Journal of Performance of Constructed Facilities

Architectural concrete has been used widely in contemporary architecture, especially because of the growing evolution associated with its shape, texture, and color. Thus, it is important to create and spread the use of appropriate tools to implement a maintenance strategy for architectural concrete surfaces. This paper presents an expert system to support the inspection, diagnosis, and repair of architectural concrete surfaces. It is composed of classification systems of anomalies, their probable causes, in situ diagnosis methods and repair techniques, and correlation matrices in which the relationship between these systems’ items is expressed. The system also includes individual files for anomalies, diagnosis methods, and repair techniques, in which each is described in detail. The objective of this system is to standardize and systematize the inspection of this type of surface to improve the inspectors’ performances. The implementation of this system supports periodic inspections within a predictive proactive maintenance strategy, improving their efficiency. The system presented was validated and adjusted through an inspection campaign of 110 cast-in-place architectural concrete walls.

In the frame of the project Rischio Sismico negli Edifici Monumentali-RiSEM (Seismic Risk in Monumental Buildings), a seismogeological reference model was developed for the historical center of the town of San Gimignano in central Italy in order to evaluate possible small-scale lateral variation of seismic hazard. To this aim, an on-purpose geological and geomorphological survey was performed along with ambient vibration measurements (both in a single station and array configurations) to characterize seismic response in the study area. Expected seismic amplification effects were quantified by considering a simplified approach developed in Italy for seismic microzoning at the municipality scale. This study provided preliminary information supporting site-specific analyses of the local seismic response and makes it possible the identify most critical situations in which eventual seismic retrofitting interventions are more urgent to reduce seismic risk.

This paper presents a numerical simulation and theoretical analysis on the collapse behavior of a reinforced concrete super-large cooling tower induced by failure of columns. The finite-element model was first validated by a collapse experiment of a 1/100-scaled super-large cooling tower and was then used to study the collapse process of the prototype tower. A simplified mechanical approach was put forward to analyze the collapse modes of the prototype tower induced by failure of columns with different numbers. The results demonstrated that the collapse process of a cooling tower resulting from failure of columns could be considered as a non-fixed axis rotation problem. The collapse modes were determined by the number of failed columns, which could be further explained by comparing flexural bearing capacities, vertical bearing capacities, and horizontal bearing capacities of the remaining columns and overturning moments, vertical pressures, and horizontal thrusts, respectively.

Silos are structures made of steel commonly used as storage facilities for grains and other bulk foods. This study presents monitoring of the structural behavior of a recently constructed large field silo structure subjected to a static grain load. Challenging full-scale tests were conducted on a steel silo that measured 14.55 m in diameter and 23.27 m in height. It was located on open farm land near Bothwell, Ontario, Canada. The silo’s internal pressure from static grain loading and its wall’s displacement and strain were measured. A complex finite-element model of the silo was then successfully developed and validated. This finite-element model furthered understanding and insights concerning the structural behavior of silos when loaded with bulk corn. The finite-element model showed that the critical stress occurred at the connection point between the silo’s vertical stiffeners and its wall; the model also showed that the maximum lateral deformation of the silo occurred approximately 1.47 m above the top surface of the silo’s concrete foundation. However, the stresses and displacements were small and within the elastic stress limit; hence, they do not pose any threat to the structural integrity of the field silo.

This paper focuses on the seismic risk assessment of historic masonry towers according to the Italian “Guidelines for the Assessment and Mitigation of the Seismic Risk of the Cultural Heritage.” The latter identifies a methodology of analysis based on three different levels of evaluation, according to increasing requirements on the structural knowledge: LV1 (analysis at territorial level), LV2 (local analysis), and LV3 (global analysis). Regardless of the methodology of analysis, the more advanced the achieved level of knowledge, the higher the reliability of these approaches becomes. In this field, a fundamental task is the estimation of the uncertain parameters (both material properties and boundary conditions) affecting the structural behavior. The effect of these uncertainties on the global structural response is herein approached through the discussion of an illustrative case study of some of the historic masonry towers in the city center of San Gimignano (Siena, Italy). The seismic risk of these towers was analyzed in the framework of Seismic Risk of Monumental Buildings (RiSEM is the Italian acronym), a research project granted by the Tuscany Regional Administration, and this paper summarizes the results obtained for two of the preceding three levels, which highlights a few issues concerning the seismic risk of historic masonry towers. Useful conclusions are drawn in order to quantify, when performing an LV3 approach through nonlinear models, the effects of the uncertainties on the seismic risk evaluation of such structural typology. The paper, in particular, confirms once more how strongly the effect of confinement reflected on tower seismic performances and stresses that specific attention should be paid to the definition of the effective portion of the structure to be considered as confined (with respect to adjacent buildings).

One of the most critical stages for a structure’s safety is its construction process, and this problem is even more acute in buildings with reinforced concrete structures. These structures are usually built by shoring successive floors, so that the most recently poured floor rests on the lower floors by means of shores. It is therefore vitally important to have calculation tools available to estimate the loads to which the shores and slabs will be subjected in each stage of construction. A number of calculation methods have been proposed to date, of which the one proposed by Grundy and Kabaila in 1963 is the best known and most frequently used. This paper analyzes the limitations of Grundy and Kabaila’s method by means of a parametric study of finite-element method simulations that identified a large number of situations in which this method presented unsafe results in terms of the estimated loads on slabs. In many situations, therefore, applying this method could gravely affect a building’s in-service behavior and durability. The paper’s final objectives are to make the reader aware of the limitations of Grundy and Kabaila’s method and the need to use the more refined methods that are now available to estimate the loads on shores and slabs in reinforced concrete buildings under construction.

This paper addresses maintenance planning in heritage buildings. Currently, social, economic, and environmental factors raise concerns about the durability and service life of buildings. This study on the service life of historical buildings in terms of functionality presents a complex analysis that has yet to be developed in great depth. In this sense, a new expert system based on fuzzy logic for the prognosis of the functional service life of buildings is established. The system developed intends to manage vulnerabilities and risk variables that affect a building’s performance. These parameters are involved in the building management and maintenance process and indicate durability in terms of serviceability as an output model parameter. The aim of this paper is to describe a new application of a fuzzy inference system based on expert knowledge. This approach discusses the serviceability of architectural heritage buildings using a Mamdani fuzzy model. In this methodology, the vulnerability and risk condition of nine theoretical case studies and five real buildings located in southern Spain are analyzed. In this case study, the application model is shown in a set of a five heritage buildings situated in southern Europe (Andalusia, Spain), which were only analyzed through in situ visual inspections. This system is able to give priorities relating to preventive conservation activities in homogeneous groups of heritage buildings. The approach gives useful information based on a functional criterion regarding the current state of the buildings. The fuzzy model aims to be an indicator for the future evolution of a building’s functionality.

This paper presents the results from a field and numerical studies performed to understand the long-term performance of a bridge approach embankment designed with lightweight, expanded clay and shale (ECS) aggregates to mitigate the settlements on a soft soil foundation. The ECS aggregates and traditional select fill were used to build southern and northern approach embankments, respectively, for a bridge on State Highway 360 in Arlington, Texas. An extensive series of laboratory tests were conducted to obtain the engineering behavior of ECS and the select fill materials before the construction. These properties were then used in the finite element modeling to simulate the embankment sections to verify the long-term performance. The embankment sections were instrumented with vertical inclinometers to monitor the lateral movements for more than four years. This data was used to validate the numerical models with an acceptable amount of accuracy. Then a parametric study was conducted for varied heights of embankments, thicknesses of foundation soil and also compression/recompression indices of foundation soil to develop design charts. The numerical, as well as field data, indicate that there is a two-thirds reduction in settlement of the foundation soil with the use of the lightweight material. The pre-consolidation pressure and the overconsolidation ratios govern the settlement behavior of the foundation soil due to lightweight embankments. The design charts can be useful in either predicting the embankment settlements for a given ECS embankment configuration or determine the allowable height of the ECS embankment for a specified settlement value when constructing in similar foundation soil encountered in this study.

The frequencies and mode shapes of high-rise buildings obtained from on-site ambient vibration testing and operational modal analysis (OMA) are very important for dynamic structural analysis and seismic design. This paper introduces a high-rise building ambient vibration test project in Laibin. Some results obtained from full-scale measurements of the dynamic behavior of 10 high-rise buildings are described. Different pre- and postprocessing techniques were used for ambient vibration signal analysis, from which the modal parameters were obtained using three OMA techniques. By rationally analyzing and modeling the stiffness of the infill walls, six finite element (FE) models were built in PKPM and SAP2000 to estimate the analytical modal information. The influences of the infill wall mass and stiffness on the dynamic properties of a high-rise building are further discussed. According to the identified and calculated results, all three modes emerged in each modal dense region in the frequency domain of high-rise buildings. Finally, based on 25 proposed empirical equations, the fundamental periods of 10 buildings are calculated and summarized.

The stability and structural performance of aged structures under extreme events are rarely investigated. The severe deterioration in current condition of aged bridges can trigger premature failures under regular floods or even mild earthquakes. A reliable bridge inspection program is required for condition assessment. Currently, Turkey, a seismically active country, does not have a regular bridge inspection program or management systems. This deficiency was highlighted by the collapse of the Caycuma Bridge in 2012, killing 15 people during a regular flood event. The main contribution of this paper is to identify the need for in-depth investigation of aging bridges by integration of bridge inspection data with bridge seismic fragility curves and to address the seismic vulnerability of these bridges with a high level of scour. In this scope, one of the inspected bridges has been selected to determine the loss of seismic load resistance attributable to floods. The investigation has included use of newly developed bridge fragility curves for Turkey and advanced nonlinear analysis.

In previous studies, reinforced concrete (RC) frame–shear wall structures subjected to partial wall removals have been investigated using the nonlinear dynamic alternate path method (APM). However, in the case of an arrested collapse, the APM is not able to obtain the residual capacity. Moreover, less attention has been paid to resisting mechanisms of partially damaged shear walls due to extreme loading on different stories. In the present study a perimeter dual system from a prototype RC frame–shear wall building is investigated using pushdown analysis. The structure is modeled based on a reliable framework established by validating modeling approaches. Load redistribution mechanisms of partially damaged shear walls are indicated and the collapse resistance is quantitatively evaluated following wall (column) removals from different stories. Based on the results, shear walls show considerably high resistance to progressive collapse, which can be implemented in collapse-resistant design. Detailed descriptions of modeling approaches and validations in this study provide guidelines for simulation of different RC structural elements under large deformations.

The many towers of San Gimignano, Italy, make this town unique in the world. While most have disappeared, the surviving towers are even today a very interesting example of ancient simple but high buildings. The construction is surprising, the method is based on very thick stone masonries and extraordinary mortars, with just a few later exceptions where bricks were used. Equally surprising is the inner space, as rooms are sometimes smaller than the wall thickness. For each of the 14 studied towers, detailed surveys were made on internal and external parts. The survey was carried out with laser scanner and traditional instrumentation. For each tower’s exposed masonries, materials and discontinuities were examined in detail, identifying demolitions and reconstructions that occurred over time. Deformations in vertical and horizontal planes and main cracking phenomena were recorded. Remarkable data on all dimensional and construction features of the medieval towers was obtained.

Knowing the flow field characteristics of pavement rainfall runoff is essential for highway drainage design and skid management. This paper presents an innovative approach to characterize the flow field properties of pavement rainfall runoff under natural rainfall events. The approach is based on two-dimensional shallow water equations with porosity to encounter pavement topography, including highway alignment, the obstructive effect of pavement surface macrotexture, and side drainage types. The model is verified with a classical dam-breaking model, and compared well with field monitoring results of water film thickness on existing expressway pavement. The capabilities of the approach to predict the flow field characteristics in temporal and spatial dimension make it useful in highway geometry and drainage design, and can also be potentially incorporated into skid and hydroplaning risk management.

The maintenance of dams is crucial because of their social, environmental, and economic relevance. However, more than 40% of the world’s dams are more than 40 years old. Furthermore, because of their ageing, damage such as cracks, leaks, and remaining movements have the potential to affect their serviceability and safety. This paper provides dam maintenance technicians with a methodology that first provides a diagnostic hypothesis, as maintenance work can only be considered if the source of the problem is known. The methodology provides technicians with tools for making decisions to ensure the short- and long-term sustainable management of a fundamental resource for societies. The analysis uses a transversal approach broken into three stages: study of the structure’s clinical history, field inspection, and analysis. These tasks are described from a technical point of view with a range of examples and graphs to demonstrate their practical usefulness and to facilitate implementation.

In buildings, mold growth can have severe consequences on the occupants’ health and on the durability of the construction. Mold growth is a complex process that depends on many factors, such as temperature and relative humidity, presence of nutrients, and exposure time. In sport facilities, vapor production is typically high and the temperature is compatible with mold development, enhancing the probability for the phenomenon to occur. Several mold prediction models are available in the literature, such as the time of wetness, the isopleth systems, the updated VTT (Technical Research Centre of Finland) model, and the biohygrothermal model. They allow estimating the mold growth incidence in building components and performing risk analysis. This study evaluates the in-service performance of a gymnasium. Mold growth and the occurrence of condensation were assessed through in situ measurements and making use of prediction models. Infrared thermography was used in the selection of critical locations on the building and superficial temperature in six points was monitored during four months. Air temperature, relative humidity, and carbon dioxide concentration were also collected. These parameters were used in the evaluation of the building’s performance and as input in the prediction models. The results obtained with the different models lead to different conclusions, creating the opportunity to discuss their strengths and weaknesses as well as their sensitivity to the input parameters.

In recent years, ground-source heat pumps (GSHPs) have been extensively used in engineering projects because of their ability to take advantage of geothermal energy and their subsequent benefits of energy saving and environmental protection. Significant progress has been made in understanding the heat exchange between ground heat exchangers (GHEs), and surrounding soils in a GSHP system. However, relatively fewer studies have been performed to investigate the influences of the moisture variations and seepage flow in the surrounding soils on the performances of the GSHP system. Karst formations extensively exist in many areas of southern China where the subtropical climate brings frequent precipitation, rich seepage water flow, and fluctuations in the groundwater table. All these factors pose huge challenges to the implementation of GSHP systems in these areas, which makes the heat exchange between GHEs and surrounding soils a coupled heat-moisture transport problem. No previous research has been dedicated to this topic. In order to understand the coupled heat-moisture transport process and its influences on the heat exchange between GHEs and surrounding soils in karst areas of southern China, a GSHP system was constructed in Guilin, Guangxi Province to monitor its performance under the combined influences of soil temperature and moisture changes. A data-acquisition system was set up to monitor the most relevant parameters of the system, such as temperature and moisture levels of the surrounding soils, climatic factors, groundwater table, and performance of the GSHP system. Three different operation-mode tests were used to simulate possible future applications under different scenarios. The test results were analyzed, from which some conclusions were drawn regarding the influences of the coupled heat-moisture migrations in karst areas on the performance of GSHP systems.

A hybrid experimental-numerical method for the standoff and quantitative analysis of metal corrosion under protective coatings is proposed based on long-wave infrared broadband imaging. This approach is based on time-lapsed measurements of surface temperature and a numerical simulation of the corresponding thermal signature. Experiments were carried out to verify the proposed methodology, while identifying the limitations and opportunities for using imaging for quantitative assessments of corrosion, particularly for use in infrastructure health monitoring. This included field studies on large natural gas pipelines in service. Results from the imaging campaign were simultaneously compared with point sensor measurements that are used customarily for pipe wall thickness evaluation, demonstrating that the full field approach provides measures of metal loss that is less than the variations in the pipe wall thickness in the noncorroded state.

Managers of highway bridge infrastructure constantly seek to improve their predictions of the physical performance of their facilities at any future time and also to identify the influential factors of bridge deterioration. In addressing this subject for concrete superstructures in particular, this paper uses empirical data from Indiana spanning 1992–2014. The superstructure design types considered are cast-in-place concrete (slab, stringer, and arch-deck) and prestressed concrete (stringer, T-beam, box-beam multiple, and box-beam single). Exponential and polynomial functional forms are investigated as part of the modeling process. A number of factors are found to have statistically significant influence on the deterioration of the concrete superstructures’ physical condition consistently across all design types, and other factors are found to be significant only for some design types. The paper also carries out sensitivity and marginal effects analyses to quantify the strength of effect of the influential factors on superstructure deterioration. Using the developed models, the paper establishes service lives for each concrete superstructure design type and compares the findings with those of past studies. The developed models can help highway agencies to carry out condition-based scheduling of bridge superstructure rehabilitation and reconstruction and to identify the materials and designs that are best suited to specific climates. This is useful for a number of agency processes including work programming and scheduling, and for feedback to bridge designers and maintenance personnel.

A residual service life prediction method based on critical life curves of selected bridge members is presented in this paper for bridges in service. The lowest target reliability index is selected as the criterion for the end of the lifecycle of bridges based on bridge design codes. Based on various assessment reference periods, a simple stochastic process model of resistance is adopted to evaluate corresponding resistance reduction coefficients related to the adopted lowest reliability index. By proposing the critical life curves based on flexural resistant capacity, the paper established a new method to predict the residual service life of bridges. A case study is used to demonstrate the proposed approach. The authors inspected 11 pieces of 13-m hollow-core slab beams that had been in use for 11 years. The accuracy of the prediction method was verified through a field condition investigation and a lab destructive test on a beam dismantled from the studied bridge.

This paper aims to explore the statistics of pavement cracks using computer-vision techniques. The knowledge discovered by mining the crack data can be used to avoid subjective crack feature selection for vision-based pavement evaluation systems. Moreover, the statistical evaluation of crack features can be used as fundamental data to justify pavement rehabilitation policies. For this purpose, surface images of flexible pavements in different deterioration stages were analyzed using a novel image-processing technique. Seven imagery features of the detected objects including area, length, width, orientation, intensity, texture roughness, and wheel-path position, which are commonly used in pavement applications, were extracted and analyzed. A comprehensive statistical analysis was performed using filter feature subset selection (FSS) methods to rank crack features based on their significance (relevance and redundancy) for the pavement crack–detection problem. Based on the results, length, intensity, and wheel-path position were identified as the optimal feature-set for the vision-based system. Statistical characteristics of crack features were also analyzed to extract accurate quantitative measures for pavement conditions assessment. The statistical characterization identified longitudinal cracks within the wheel path as the dominant defect of the validation data set. Such information can help management agencies make informed pavement maintenance policies.

The majority of housing tenements in developing countries constitute a class of structure termed open ground story (OGS) of medium rise and highly vulnerable to strong seismic motions. Evaluation of the displacement demand magnifier (DDM) for quantifying the vulnerability of OGS structures and variations in the DDM with reference to the stiffness ratio (between OGS and infilled story) represent the contribution of this paper. The relationship between the stiffness and frequency ratios of the first two bending frequencies is established and highlighted. A methodology for evaluating the DDM of an existing OGS structure through measurement of frequencies in situ is established and validated. Expressions for computing the demand capacity ratio (DCR) of OGS frames have also been derived. The developed procedure is applied to an OGS structure that was damaged during the 2001 Bhuj earthquake. A formulation to compute the bending frequencies of a free-free discrete frame is derived, which is also a contribution. Details of the shake table experiment conducted to validate the given hypothesis are presented. To establish proof of concept, ambient vibration measurements have been taken on an existing OGS structure and its DDM is evaluated.

Sandwich panel systems offer many advantages over other conventional systems, which facilitate their use in several applications, including aerospace, naval, and transportation. The complexity and relatively high cost of sandwich panel system design and fabrication have limited its application in civil engineering applications. In accordance with North American standards for blast-resistant design of buildings, the dynamic behavior of a system can be predicted using its static resistance function obtained under equivalent uniform loading. The goal of this study was to quantify the quasi-static resistant function of novel cost effective lightweight cold-formed steel sandwich panels to be used in the context of blast-resistant structures. An analytical model has been introduced to predict the elastic characteristics of the proposed sandwich configurations and to assess the critical failure modes. In addition, an experimental program was performed involving eighteen sandwich panels under uniform quasi-static loading. Different configurations were investigated, including longitudinal and transverse corrugated core sandwich panels, using different deck profiles. The modes of failure experienced by the test panels were assessed and discussed and were found to be consistent with predicted failure modes. The quasi-static resistance functions for the proposed sandwich panel configurations were characterized in terms of yield loads and ultimate capacities and the corresponding displacement values. Analytically predicted values were compared to the experimental findings and found to be in a good agreement. The influence of sandwich panel core configuration and core sheet thickness on the behavior of the sandwich panels was examined, considering energy absorption and ductility. The results of the current study are expected to serve future development of cost-effective sandwich panels to be used as sacrificial cladding for the blast protection of structures.

Because traffic and environmental loadings cause concrete pavement failure, a large budget is allocated for maintenance. Through understanding the effect of traffic and temperature loadings on pavement behavior or performance, concrete pavement design can be improved. Hence, this study focuses on the behavior of jointed concrete pavement (JCP) with traffic and temperature loadings by analyzing data from a test road in Korea. Strain gauges, displacement sensors, temperature sensors, and demec gauges were used to evaluate JCP behavior. Static loading, temperature loading, and falling weight deflectometer tests were also conducted. Strain, stress, vertical movement, and joint movement were evaluated based on different slab thicknesses, measurement locations, and substructures. Overall, temperature loading was a governing factor in JCP movement. Measurement location, thickness, substructure, and depth also affect JCP behavior. In the future, the behavior of JCP will be clearer with more acquired data, which will be used in the design of Korean concrete pavement.

This study develops and validates a conceptual model of the role of built environment resilience to natural disasters by conducting an overall case study of the Wenchuan earthquake. This research shows that the enormous losses resulting from the Wenchuan earthquake were largely attributed to failures of built environment, which also severely affected local emergency response and external aid. The significant disparities in dwelling destruction and income between rural and urban dwellers further reveal that socially disadvantaged conditions increase the vulnerability of built environments in rural areas. The lessons learned from Wenchuan earthquake indicate how it is critical to consider both the resilience of built environments to withstand external impacts and the vulnerability to the natural environment by adequate identification and assessment of hazards, proper land use planning, setting of appropriate design codes, application of natural hazard–resistant technologies, and strict construction process management. Fundamentally, creating incentives for equitably allocating resources to mitigate disasters in inland rural communities of developing countries should be a policy emphasis to facilitate sustainable project development.

This paper summarizes the main aspects of geotechnical modeling and soil–structure interaction analyses performed for the seismic risk assessment of the San Gimignano towers. Morphological, stratigraphic, and geotechnical characterization of the subsoil is described in the first part of the paper. The results of a geotechnical survey (including two borings with standard penetration tests, downhole tests, and laboratory tests on three undisturbed samples, both in static and dynamic conditions) are described and analyzed. Seismic ground response as well as soil–structure interaction analyses are presented in the second part of the paper. One-dimensional ground response analyses were performed by using a probabilistic approach, and the results were compared with those from ambient noise vibration measurements. The seismic input motions were selected from existing databases of actual strong motion recordings, according to seismic hazard of the site. Soil–structure interaction analyses were performed on a simplified model of the most important San Gimignano tower (Torre Grossa) by applying a numerical multistep method based on the principle of superimposition. The comparison of the obtained results with those presented in previous studies for fixed-base conditions shows small differences (approximately 2%) in the fundamental period of vibration of the tower estimated by means of the different approaches.

This paper investigates the response of tilt-up (referred to as “big-box”) buildings subjected to two extreme hazards to which they have been observed to be susceptible—high winds (tornadoes) and earthquakes—through a performance assessment methodology utilizing fragility analysis. The methodology focuses on load characterization, defining performance goals and corresponding limit states, and assessing performance through fragility analysis. Performance goals and limit states accounting for the performance of big-box buildings during past tornado and earthquake events in the United States are identified, as are research findings reported in the literature. The proposed methodology is applied to a set of four big-box buildings representative of the current building stock in the United States, i.e., building archetypes. The building archetypes incorporate concrete tilt-up wall panels and in-plane flexible roof diaphragms that vary in size, plan aspect ratios, and roof diaphragm connectors. The results of this study show that the building size (footprint) significantly affects the performance of big-box buildings subjected to tornado wind loads but the roof connector variability does not influence the building response, given that the roof joists failed before the roof decks connections. In contrast, the performance of big-box buildings subjected to earthquake loading is highly associated with the roof diaphragm connectors used in the design phase, which are the main source of inelasticity in the roof system.

Construction of a subway station in Shanghai called for a 31.4–33.1–m-deep excavation, which extended through upper impermeable clayey strata into underlying erodible silt and sand aquifer layers. When the north section of this pit nearly bottomed out on July 23, 2013, a sudden outburst of groundwater took place and the pit base was flooded quickly. In the subsequent two days, the adjacent ground and building successively underwent 30–42-mm settlements in a plunging manner. To prevent aggravation of the situation, a contingency plan was initiated quickly in an attempt to seal off the water flow path. By constructing mixed-in-place and jet-grouting piles respectively along the outer and inner perimeters of the diaphragm wall where leakage occurred, flow channels were successfully blocked. Despite this, the building adjacent to the outburst of groundwater suffered long-term postexcavation settlement. Forensic diagnoses show that this through-wall leaking accident was related to two major factors: (1) ignorance of minor leakages emerging two weeks before without adopting any remedial measure; and (2) a flawed slab connector embedded in the confined aquifer layer. Based on visual inspection and retrospective analysis of field monitoring data, the possible leakage flow path and associated ground subsidence zone were mapped and a settlement history of the affected building was reconstructed. Both contractual and technical lessons learned from this accident will be useful for professionals to mitigate or prevent future incidence of through-wall leakage during excavation.

On October 23 and November 9, 2011, two earthquakes struck the Van Province in eastern Turkey. Masonry buildings in the region were severely damaged. This paper presents an investigation on the seismic performance of masonry dwellings after the 2011 Van earthquakes. The seismicity of the region and its seismic hazards were considered, and a door-to-door reconnaissance study was conducted after these strong earthquakes to examine the seismic response of the masonry structures. Rural regions particularly suffered extensive damage from these earthquakes, and the reasons for the observed damage are complex. Regulations of the current Turkish earthquake code for masonry structures were compared with field observations, and the latest and draft versions of the code regarding masonry buildings were evaluated. Approaches to enhancing the seismic behavior of masonry dwellings are discussed. On the basis of the field investigation, the construction quality and control issues were fundamental factors that affected the performance of masonry dwellings. Hence, out-of-plane and in-plane behaviors contributed to the observed damage.

This paper analyzes the typical landslides caused by pipeline construction and the characteristics of landslides during the construction period, and assesses the risk to the long gas and oil pipeline project in China caused by landslides during its construction. Using the semiquantitative risk assessment method and introducing the concept of risk degree, according to the assessment of risk and vulnerability, a landslide disaster risk assessing index system was established after summarizing the causative disaster factors of the landslide disasters induced by the construction of the China-Myanmar pipeline project. Three typical disaster points induced by pipeline construction were chosen to make a risk grade evaluation. The results of site reviews show the evaluation results coincide with the actual situation. Thus, semiquantitative evaluation methods can be used as a reference to guide the landslide disasters developed portion of pipeline construction risk control.

With the advantages of both granular piles and rigid piles, pervious concrete piles (PCPs) are especially suitable for improving ground bearing capacity. To study the dynamic performance characteristics of PCP composite foundation under earthquake loads, the acceleration response of subgrade and the development and dissipation of excess pore water pressure in composite foundation during the earthquake were numerically calculated. The dynamic performances of PCP were compared with those of gravel pile and low-grade concrete pile. The surface acceleration amplification coefficient of PCP composite foundation is obviously smaller than two other composite foundations. Meanwhile, its predominant period is only half that of the gravel pile and low-grade concrete pile composite foundation, which demonstrates that PCP composite foundation is more effective for avoiding the mechanical resonance of the upper building. Besides the significant damping effect, it also has obvious pressure-reduction effect. The excess pore water pressure induced by an earthquake dissipates quickly because of the high permeability of PCPs, and foundation liquefaction is effectively inhibited. Consequently, the draining-damping coupling effect of PCPs can improve deformation compatibility of soil during the earthquake.

In the present paper, a numerical model for deformation and fracturing of brittle rocks is used to study the damage evolution and localized fracturing of brittle rocks based on statistical mesoscopic damage mechanics. In the model, material heterogeneity and the mesoscopic renormalization concept are introduced to consider the interaction among microcracks in rock. The temporal and spatial evolution of acoustic emissions in the stressed rock are also described. Correspondingly, numerical tests on rock specimens with different heterogeneities, porosities, and scales are performed to investigate the damage evolution and localized fracturing of brittle rocks. The localized damage and fracturing of brittle rocks induced by microstructural damage is investigated. The study shows that heterogeneity, porosities, and scales of rock specimen have significant impact on damage evolution and localized fracturing mode. In addition, the study reveals that the postpeak response of stress-strain curve is due to the deformation of the structural elements, and localization means that the descending branch of the stress-strain curve of the rock specimen is size dependent, and the stress-strain curve can therefore not be regarded as a pure material property.

The Escollera Tower was supposed to be the tallest building in Colombia in 2007 with a total projected height of 200.3 m. However, on May 13, 2007, when the tower reached the height of 152.3 m, an unusual wind hit the city of Cartagena, affecting the structure of the building. It swayed approximately 1 m at the tip of construction, resulting in significant damage to the columns and made it impossible to continue construction. The tower was disassembled through the intervention of the society of engineers and architects from Bolivar, Colombia. The failure took place in the structure that only consisted of beams and columns; the original design that included lateral bracings was ignored. This research studied slenderness effects, stress levels, and lateral displacements of the Escollera Tower structure for basic loading, and for wind actions with and without bracing. The analysis of the tower used FEM to account for the geometry of the original cross sections. Results show how the lack of bracing during construction and a lack of detail during the design stages of the structure led to unexpected displacements and bad structural behavior under a midintensity wind, which could have been accounted for if modeled with proper details at the time of design and construction.

The paper reports the results of a blind benchmark developed as a part of the preliminary activity of the research project RiSEM (Italian acronym for Seismic Risk on Monumental Buildings). The benchmark was aimed at comparing the results obtained with different analytical models and/or numerical analysis techniques (variational approach, finite elements, macroelements, equivalent frame, etc.) for the assessment of the nonlinear structural behavior of two cantilever masonry elements with different slenderness. The analyzed elements were characterized by a deliberately simple geometry, and the comparison between the numerical results had a twofold purpose. On the one hand, it aimed at estimating the effects of the epistemic uncertainties that are related to the different models and numerical techniques. On the other hand, it aimed at reaching a proper evaluation of the influence of parameters describing the postelastic behavior of the structural typology analyzed within the research project (specifically, the masonry towers). Both these objectives were necessary to further proceed with the development of simplified numerical models needed for the subsequent risk analysis. For both slendernesses, the results have highlighted a significant dispersion of both the displacement capacity and postpeak softening branch of the capacity curves. In addition, after some elaborations it has been observed that the dispersion of the results is proportional to both the shear-force and displacement level.

Jumping and hopping are considered the most severe human loading scenario for stadiums and gymnasiums. Recent design methods examine floor vibration by requiring knowledge of the dynamic characteristics of the floor structure (i.e., peak acceleration and fundamental frequency). However, these standards do not include a long and light structure such as the prestressed cable reinforced concrete truss (PCT) system considered in this study. Therefore, accurate assessment of the vibration behavior of such structures subjected to jumping and hopping is warranted. An experimental study (lab and in situ) aiming to investigate the vibrational properties and dynamic response of PCT floor systems was conducted. This study involves both jumping and hopping tests for verifying whether the characteristics are vibration acceptable. The measured responses of the floor systems were evaluated against the ISO 2631-2 limit for maximum acceleration. Lastly, a more rational method for determining fundamental frequency and peak acceleration is proposed.

A variety of complex modeling techniques is available to estimate the onset of chloride-induced corrosion in reinforced concrete infrastructure. Despite great progress in this area during the last two decades, many important structures have been designed using very simple diffusion models that are informed by basic laboratory testing. This paper describes an evaluation of the effectiveness of simple models and tests by analyzing a concrete comprising key components of an 8.4-km-long (5.2-mi-long) coastal bridge constructed on the Outer Banks of North Carolina that provides critical access to the mainland. A comparison of chloride permeability results was made between laboratory-mixed test batches of concrete and field-mixed concrete. Concrete specimens were prepared in the laboratory with identical mix designs to material specified for construction of the subject bridge. The test batches were evaluated by ponding with a 3% chloride solution as well as with the rapid chloride permeability test (RCPT). In the field, cores and concrete powder samples were removed from the coastal bridge after 2.2 years of exposure and again after 10.1 years, and the diffusion coefficient was determined. Results from the laboratory and the field were used to evaluate the efficacy of using laboratory-generated chloride diffusion parameters to model the ingress and service life of concrete mixed and placed in the field. Results showed good correlation between the performance of the laboratory-mixed concrete and the field mixed concrete. The durability modeling parameters used by North Carolina Department of Transportation (NCDOT) designers were also found to be accurate and conservative.

Currently there are around 14,000 bridges serving both major and minor transportation systems in Taiwan. Damages incurred to these bridges would surely affect the social and economic well-being of the society. In this study, after analyzing more than 900 pieces of data regarding bridges in Taiwan, it was found that in terms of overall bridge damage, bridges that have been in service 15 years or more, located farther from the ocean, and designed to resist seismic activities have a higher possibility to sustain overall structural damage; in comparison, bridges that have been in service 10 years or less, have more than four traffic lanes, and are designed as T-girder or I-girder are less prone to overall damage. In terms of severity of damage, bridges that are located farther from the ocean, crossing poor flow conditions, and possess a gravity type-deck are prone to more severe damage, while bridges designed as plate composite structures and possess asphalt concrete pavement are less prone to severe damage. In the life span of a bridge, the planning and design phase accounts for 4–6%, the construction phase 4–6%, and the service/maintenance phase 88–92%. It is clear that the maintenance of a bridge constitutes a major portion of the overall cost. Therefore, if managed well, periodic inspection and occasional retrofitting can reduce the life-cycle cost of a bridge project.

Sliding base isolation can achieve independence between the seismic isolation period and the liquid sloshing period. Additionally, it has dissipation advantages for liquid-storage structures. However, when earthquake actions are large, the isolation layer displacement exceeds the limit value, which can lead to auxiliary pipeline damage and liquid leakage. Therefore, a corresponding displacement-limiting study is necessary. Considering the liquid-solid interaction, a simplified model of a rectangular liquid-storage structure (RLSS) with arc displacement-limiting devices is established, and its validity is verified using numerical calculations. Based on the structural safety and deformation capacity of the displacement-limiting device, the limit of the isolation layer displacement is defined. The factors affecting the hysteretic energy dissipation of the displacement-limiting device and the dynamic responses of the RLSSs are studied. The results indicate that the section size and radius of the arc limiting device considerably influence its hysteretic energy dissipation, but the effects of the cross section shape are extremely small. When the friction coefficient is reasonably designed, the wall tensile stress and liquid sloshing height of the sliding base-isolated RLSS with limiting devices can be effectively reduced. This new damping method is of great significance for the prevention and control of the two common types of failure modes for concrete RLSSs, namely, wall cracking and liquid overflow.

The capacity of the Wuku-Yangmei freeway is insufficient for developing the Taoyuan Aerotropolis. To provide more traffic lanes to the existing freeway, a series of pier foundations at the freeway embankment have been constructed for the Wuku-Yangmei Overpass, meant to ease peak-hour congestion between Taipei and Taoyuan. The H-section with a horizontal wale strip has been widely adopted as an effective shoring measure in Taiwan. However, this may not be applicable as the presence of cobble in the lateritic soil formation may cause difficulties in installing H-sections for excavation. Soil nailing and an alternative shoring method with ring beams at the slope and a composite shoring system at the shaft were applied to Piers B7 and C15, respectively, to compare their slopes’ lateral displacement, lateral displacement–time curve, and surface tension cracking. Field measurements indicate that the rectangular shaft with a soil nail shoring system is not effective at limiting the lateral displacement, leading to the slope sliding incident. Three-dimensional finite-element analyses using the input parameters that are back-calculated by comparing the lateral displacement–depth curves to the inclinometer data have been conducted. The modeling results are found to be in reasonable agreement with the inclinometer data and the shear strain increment profile may give a better understanding of the sliding surface position.

An understanding of the failure patterns of pipes in water distribution systems is critical to cost-effective system-maintenance planning. Failure patterns, which typically measure the frequency of water main breaks in a water distribution system, can vary widely depending on the type of pipe material being considered, and statistical analysis of pipe frequency-of-failure data is complicated by limited data on soil conditions, freeze-thaw cycles, construction quality, and so on, which manifests itself as unobserved heterogeneity. The current paper considers failure frequencies in polyvinyl chloride (PVC) pipes using pipe-break data from a 21-year period in Indianapolis, Indiana. Failure frequencies were studied using a random parameters negative binomial (and a latent class negative binomial) to account for possible unobserved heterogeneity in the data and to assess the systemwide monthly frequency of PVC pipe breaks as a function of a number of observable explanatory variables. The results indicate the importance of pipe diameter, length, and age, and environmental conditions, in estimating monthly break frequency. This paper provides an important demonstration of method (the application of heterogeneity models), and the model estimation results provide insights into pipe-failure frequencies that can be used as guidance for both maintenance-crew allocations and targeted inspection of PVC pipes. Future databases, which may include detailed information on soil conditions, freeze-thaw cycles, construction quality, and other factors, can provide additional heterogeneity-related insights using the methods proposed in this paper.

Adjacent box-girder bridges are commonly built in United States because of their fast, easy, and economical construction. They have shown good performance and service life except for frequent longitudinal cracking in the shear keys. Past research attributed the development of longitudinal cracks in shear keys primarily to temperature fluctuations. However, it is not obvious how temperature fluctuations cause the shear keys to crack. An adjacent box-girder bridge with partial depth shear keys and transverse tie bars was instrumented at the time of construction and subsequently monitored to study temperature effects. A finite-element model of the bridge was used to study the behavior of the bridge generally and failure modes that partial depth shear keys experience under daily and seasonal temperature fluctuations. The bridge girders move considerably in the transverse direction, and each girder expands or contract individually in response to temperature changes. The failure in the shear keys appeared to be caused by these environmental loads, which can be exacerbated by truck loads. Tie bars did little to stop this type of failure.

Analytical fragility analyses are conducted to investigate the impact of seismic design level on the seismic performance of RC moment-resisting frame buildings designed according to the provisions of the current Chinese seismic code. Four groups of buildings of low-to-mid height (3, 5, 8, and 10 stories) are studied, each of which accounts for diverse levels of seismic design, namely, precode, low code, medium code, and high code. Fragility relationships are derived for each building using nonlinear time-history analyses with 100 real ground-motion records. The results show that the buildings designed for a higher seismic code level exhibit less fragility as improving the seismic design level leads to a raised fragility median and a reduced fragility dispersion. Data on the reference seismic hazards with the probabilities of exceedance of 10 and 2–3% in 50 years show that almost all the buildings can satisfy the performance requirements of reparability and no collapse, respectively. However, the damage limitation performance objective, which is associated with 63.2% in 50-year hazard, cannot be satisfactorily achieved by medium-code and high-code buildings. The enhancement of structural resistance caused by the improvement of seismic design level is counteracted by the simultaneously increased seismic action; therefore, the limit-state probabilities of the buildings at the corresponding reference earthquakes are not decreased but increased accordingly. The current Chinese seismic design code seems conservative because the buildings show marginal potential of suffering serious damages endangering life when subjected to the seismic hazard level higher than it was designed for. Thus, it is possible to account for larger anticipated nonlinear behavior in the definition of seismic design force.

A timely and effective postearthquake recovery could minimize the impacts and disruption that have arisen due to the induced physical damage to sewerage pipelines. The knowledge of the restoration time could facilitate the efficiency of the recovery. This paper presents a statistical model for predicting the time required to restore sewerage systems after earthquakes and to test the applicability and adaptability of the proposed approach to other areas. Using a database of 4,648 pipes that have been repaired or renewed in Christchurch, New Zealand, after the Canterbury earthquake sequence in 2010–2011, four candidate statistical models and approaches, namely, accelerated failure time, Cox proportional hazard, random survival forest (RSF), and multiple linear regression, are compared and validated. The RSF approach is found to have the best prediction power for estimating restoration time of the impaired sewerage pipelines postearthquake using the random sampling validation approach. Furthermore, key variables that have significant influence on predicting the restoration duration of sewer pipelines are identified. Finally, restoration curves are produced for informing decision makers and the public regarding pipe restoration rates after earthquakes.

Recent terrorist attacks on civil engineering infrastructure around the world have initiated extensive research on progressive collapse analysis of multistory buildings subjected to blast loading. The widely accepted alternate load path method is a threat-independent method that is able to assess the response of a structure in case of extreme hazard loads, without the consideration of the actual loads occurring. Such simplification offers great advantages, but at the same time fails to incorporate the role of a wider damaged area into the collapse modes of structures. To this end, the investigation of damage distribution on adjacent structural members induced by blast loads is considered critical for the evaluation of structural robustness against abnormal loads that may initiate progressive collapse. This paper presents detailed three-dimensional (3D) nonlinear finite-element dynamic analyses of steel frame buildings in order to examine the spatially distributed response and damage to frame members along the building exterior facing an external blast. A methodology to assess the progressive collapse vulnerability is also proposed, which includes four consecutive steps to simulate the loading event sequence. Three case studies of steel buildings with different structural systems serve as examples for the application of the proposed methodology. A high-rise (20-story) building is firstly subjected to a blast load scenario, while the complex 3D system results in the heavily impacted region are compared with individual single-degree-of-freedom (SDOF) column responses obtained from a simplified analytical approach consistent with current design recommendations. Parameters affecting the spatially distributed pressure and response quantities are identified, and the sensitivity of the damage results to the spatial variation of these parameters is established for the case of the 20-story building. Subsequently, two typical midrise (10-story) office steel buildings with identical floor plan layout but different lateral-load-resisting systems are examined; one including perimeter moment-resisting frames (MRFs) and one including interior reinforced concrete (RC) rigid core. It is shown that MRFs offer a substantial increase in robustness against blast events, and the role of interior gravity columns identified as the weakest links of the structural framing is discussed.

This paper describes the development of a course in forensic engineering at Universiti Teknologi MARA for civil engineering students at the bachelor degree level. The course is designed to give a broad introduction to the application of engineering and sciences on construction failures. The study of construction failures will offer students valuable insights into associated technical, ethical, and professional issues. Topics related to structural failures, geotechnical failures, and infrastructure failures are covered in this course. At the end of the course, students should be able to identify, evaluate, and provide solutions to real-life engineering problems. Particular reference is made to the implementation of the case-based method in teaching and learning. This method has been found effective in blending real-world problems and applyingtheoretical knowledge. Lessons learned from the case studies will help students avoid making the same mistakes and become better prepared to join the workforce.

In this paper, the performance of a full-scale single-story confined masonry building was investigated by subjecting it to quasi-static cyclic loading. The configuration and materials used for the test specimen were typical of those found in the northern areas of Pakistan as well as in the surrounding regions. The retrofitting of the building was done using ferro-cement overlay and cement-based grout injection. Damage mechanism and force-deformation behavior of the retrofitted structure are compared with those of the original structure to quantify the beneficial effects of the retrofitting. It was found that the lateral stiffness, lateral load, and deformation capacity of the retrofitted building were improved, whereas the ductility decreased slightly. The damage mechanism was transformed from mixed compression-flexural-shear to a more stable flexural-rocking mode. The results from this paper are expected to guide future research efforts on developing design recommendations for, and vulnerability assessment of, similar buildings around the world.

A stochastic time-based deterioration model for use with New Zealand bridges is presented, comprising two parts and being based on the condition management process that is used to assess the extent and severity of a defect, or defects. The first part is an expert-based severity deterioration model, which can be used to simulate the deterioration of timber, concrete, and pretensioned and steel load-bearing elements. The second part is the data-derived extent model, which uses a novel approach, not previously used, to simulate the growth of defects with time. By creating these extent and severity models, the general absence of deterioration models in the Australian and New Zealand region is addressed. Furthermore, the development of both the extent and severity models was achieved in a data-constrained environment, which led to validation and development challenges. How these challenges were dealt with, and the novel methods that were used to solve them are also covered.

A critical problem in evaluating the structural behavior of simply supported girder bridges is the performance of the transverse connectivity of girders. Traditional structural calibration factors, which are based on loading test results, are only capable of evaluating the load-bearing capacity of girders. To resolve the difficulty in evaluating the transverse connectivity performance of existing simply supported girder bridges, two parameters $P_n$ and $P_m$ were proposed based on the loading tests results of 65 simply supported concrete girder bridges. Moreover, threshold values for these two parameters were specified according to statistical analysis of loading tests results: when $P_n\le 0.3$ or $P_m\le 1.0$, the bridges perform well as a complete structure in the transverse direction, and only minor repairs are needed; when $P_n>0.3$ or $P_m>1.0$, the bridges perform poorly in the transverse direction and necessary repairing measures should be taken. Based on the data of the two evaluation parameters of surveyed bridges, a detailed strengthening strategy was established and successfully implemented in 13 field projects. According to the strengthening strategy, the following steps are to be conducted: (1) remove the damage zones in bridges, (2) rebar embedding in hinge joints, (3) install reinforcing steel grids, and (4) concrete repair. Comparative tests were made on bridges before and after the strengthening process. The results confirmed the feasibility and efficiency of the proposed strategy.

Taking advantage of the structural health monitoring system installed on the steel truss arch girder of the Dashengguan Yangtze Bridge, the monitoring correlation between strain and uniform temperature at night is obtained, and then the correlation analysis of wavelet packet decomposition is carried out, which can effectively decrease the discreteness of the monitoring correlation. After that, the whole finite-element model of the Dashengguan Yangtze Bridge is simplified into one top chord member, one diagonal web member, and one bottom chord member with imposed displacement movements on the supports. The simulated correlation between static strain and temperature is calculated using the flexibility equation of force method from the simplified finite-element model, which is close to the monitoring correlation, and the first-order derivative of flexibility equation is used to remove the influence of temperature action. Furthermore, the influence of degrading axial flexibility is analyzed, showing that the linear slopes $k_A\sim k_H$ are primarily affected by the degradation of chord members $\{T{C}_{a,-2},T{C}_{a,-1},T{C}_{a,0},T{C}_{a,1},T{C}_{a,2},T{C}_{a,3}\}$, $\{T{C}_{b,-2},T{C}_{b,-1},T{C}_{b,0},T{C}_{b,1},T{C}_{b,2},T{C}_{b,3}\}$, $\{B{C}_{a,-2},B{C}_{a,-1},B{C}_{a,0},B{C}_{a,1},B{C}_{a,2},B{C}_{a,3}\}$, and $\{C{V}_{a,1}\}$, and using the monitoring data, the method of detecting and locating the aging truss members is finally put forward.

Unfortunately, available probabilistic seismic hazard studies are reporting significantly varying estimates for seismicity of Dubai. Given Dubai’s rapid economic growth, it is crucial to assess the impact of the diverse estimates on the performance and cost of buildings. This research investigates and quantifies the impact of the high and moderate seismicity estimates of Dubai on the seismic performance and construction and repair costs of buildings with 6, 9, and 12 stories. The reference buildings are made up of reinforced concrete with special shear walls as their seismic force–resisting system. The seismic performance is investigated using nonlinear static and incremental dynamic analyses. Construction and repair costs associated with earthquake damages are evaluated to quantify the impact. Results showed that designing for higher seismicity yields significant enhancement in overall structural performance. In addition, the higher seismicity estimate resulted in slight increase in initial construction cost. However, the increase in initial investment is outweighed by significant enhancements in seismic performance and reduction in earthquake damages. This resulted in overall cost savings when reduction in repair and downtime costs are considered.

Expansive soils are known to be a serious hazard to buildings and the infrastructure industry. Saudi Arabia is located in a semiarid region where extremely dry expansive formations are frequently inundated by either household drainage or rainfall and storms. This review is aimed at investigating the procedures and methods used in variable parts of a semiarid region (Saudi Arabia) as applied by the municipalities or project owners to prevent or at least reduce the potential hazards of expansive soils. The work covers an extensive review of the published literature on the subject related to Saudi Arabia. Tabuk and Northwestern areas are among the most affected parts. The city has grown and expanded in recent decades as many major projects were constructed. The economic loss due to expansive soils in Saudi Arabia is estimated in hundreds of millions of U.S. dollars. Various solutions practiced in this area are presented. Discussion of alternative approaches can serve as a useful guide for the engineering communities and contractors. Highlights of the successful approaches in the region are shown.

Response of three masonry residential structures to blast-induced ground vibrations was measured to determine their sensitivity. Upper and lower corners, and midwall displacements were measured during blasting events, and induced strain levels in the walls were calculated and compared with the failure strains of the weakest material composing the structures walls. Presented are the methods of measurement and the results of three case studies conducted at a coal mine and two quarries. Wall strains induced by blasting vibrations were lower than the failure strains for the weakest material comprising the building walls, which indicates that blasting could not produce cracking.

This paper investigates the significance of the different types of design documents’ deficiencies (DDDs) by both contractors and consultants involved in large construction projects. Sixteen different types of DDDs were identified and classified under six different groups. Based on the significance index of the different types of DDDs, the top five ranked DDDs from the perspectives of contractors and consultants are nonconformance to building codes, design errors, specifications errors, operational issues, and lack of design team coordination. Lack of use of constructability analysis in the production of the design documents was ranked high by consultants. The test of agreement on all types of DDDs between contractors and consultants showed a high level of agreement. The study recommended that building codes should be instituted in Saudi Arabia, and consultants should conduct constructability analysis to reduce the level of deficiencies in the design documents.

An EF2 (Enhanced Fujita Scale Rating 2) tornado that hit the City of Moore, Oklahoma, on March 25, 2015, provided a rare opportunity for engineers to observe the performance of structures built to the new Moore building code high-wind provisions when subjected to a design-level event. Observations of damage to several residential structures and one commercial building were made in the immediate aftermath of the tornado. These observations were used to compare the performance of the engineered commercial building and residential structures in the same area. The conclusions made from the observations described in this paper are anecdotal and based on a limited amount of data, but indicate that residential structures constructed using the building code improvements made in Moore, Oklahoma, in 2014 perform as expected when subjected to the winds associated with an EF2 tornado. The robust structural system led to only minor damage, which could be quickly repaired.

Deteriorating and failing federal facilities represent a significant cost to the U.S. government. In maintaining these assets, the United States Air Force currently uses a facility data system to assess the reliability of building components; however, the necessary probabilities of failure are not predicted. This paper proposes a probabilistic model by using fault trees with fuzzy logic to predict the probability of failure, and therefore reliability, at the system level of a building’s infrastructure hierarchy. Through the ordered weighted averaging (OWA) operator, the method provides a basis for risk assessment by weighting probabilities of failure with the consequences of failure. After validating the method using real-world Air Force data, the proposed OWA model is statistically shown to be a significant improvement over the current condition index method for predicting future repair and replacement needs for building systems. The additional insight provided by the probability-based model provides another tool to evaluate building systems. This should help facility engineers and managers develop more effective long-term strategies to maintain systems and defend their budgetary requirements.

A large portion of the railway bridge stock in many countries is comprised of masonry arch bridges. During recent years, more attention has been paid to the maintenance of such structures. Rehabilitation and retrofitting methods have been proposed to enhance the performance of masonry arch bridges and extend their service life. Because a large portion of forces exerted on such structures comes from the railway track and passing trains, structural elements are added to the track to reduce the forces transmitted to bridges. One such element is the ballast mat, which, according to suppliers, has a positive impact on the structural performance of the track. This paper tries to assess the effects of ballast mats on the structural performance of masonry arch bridges through dynamic load tests. To do so, a 70-year-old masonry arch bridge was instrumented with deflection meters and accelerometers and dynamic load tests were carried out before and after installing ballast mats. According to test results, vertical deflections at different points on the bridge remained the same, with a deviation of less than 2%. On the other hand, vibrations on the structure were reduced significantly. Vibrations at different locations in the structure were reduced in the range of 65–85%.

Most commonly used bridge condition rating systems utilize data emanating from visual inspection reports, inevitably associated with considerable uncertainty. This could possibly lead to unnecessary repair actions or overlooking critical problems. Although the advent of nondestructive testing (NDT) technologies has significantly aided more precise assessment of bridge decks, such techniques have not received due attention in the bridge rating process. Therefore, in the present study a systematic integrated condition rating procedure for concrete bridge decks using fuzzy mathematics has been developed. Infrared thermography (IRT), ground-penetrating radar (GPR), and visual inspection are employed to identify and quantify surface and subsurface defects. The fuzzy synthetic evaluation (FSE) approach was utilized to convert the measured defects into fuzzy condition categories, which were then integrated to develop an overall bridge deck condition index (BDCI). The information sought to identify the parameters affecting the integration process were gathered from bridge engineers with extensive experience and intuition. The developed rating procedure and its application are demonstrated through a case study on a full-scale reinforced concrete bridge deck. The results revealed that rating a bridge deck based solely on visual inspection can overestimate or underestimate its condition index, while integrating NDT techniques can provide a more reliable rating. The proposed methodology could provide bridge stakeholders with a rational appraising tool for the condition of bridge decks, allowing better allocation of budgets and more precise maintenance decisions.

This paper outlines the damage observed in seven world heritage sites within the Kathmandu Valley because of the Gorkha seismic sequence of April–May 2015. Field reconnaissance was performed twice after the main shock of moment magnitude ($M_W$) 7.8 on April 25 and after the strongest aftershock ($M_W$ 7.3) on May 12. In this paper, structural damages were classified and forensic interpretation of structural performance during four major earthquakes since 1934 is presented. A new damage function is defined for the heritages, which could affect the structural performance. Causes of damage are discussed on the basis of geology, terrain characteristics, and structural deficiencies of assessed structures. Four types of heritages were identified: pagoda, Shikhara, dome and Greco-Roman. The dome was found to be the most resilient, followed by pagoda and Shikhara, and Greco-Roman heritages were identified as the most vulnerable structures. Along with the damage report, lessons learned in terms of damage and survival of heritage structures are disseminated in this paper.