Journal of Performance of Constructed Facilities

Condition assessment models are considered as an evaluation tool that can be used by decision makers to accurately evaluate and assess the condition of pipes. Condition assessment of pipes helps in reaching better decisions in terms of repair or replacement before their failures. This paper presents a condition assessment model developed for gravity and pressurized pipelines in sewer networks using integrated fuzzy analytical network process (FANP) and Monte Carlo simulation techniques. Factors affecting gravity and pressurized pipelines in sewage networks were studied and included in the developed model. A questionnaire was distributed to experts in the field, to determine the weights of 17 factors for gravity pipelines, in addition to the operating pressure for pressurized pipelines. The developed model uses a weighted scoring system to determine a numerical value indicating the condition of pipelines. FANP was used to determine the weights of the factors affecting pipeline assessment, while Monte Carlo simulation was used to determine the final scores by probability distributions fitting. Actual data for an existing sewage network in the state of Qatar was used to validate the developed model. The developed model was able to satisfactorily assess the conditions of deteriorating sewer pipelines with an average validity of approximately 85%. The developed model is expected to be a useful tool for decision makers to properly plan for their inspections and provide effective rehabilitation of sewer networks.

As territorial authorities, government agencies, and other large-asset owners were responding to regulatory and market forces in the wake of the 2010–2011 Canterbury, New Zealand, earthquakes by assessing and planning retrofits for buildings determined to be particularly vulnerable to earthquakes, an opportunity existed to identify and taxonomically classify structural seismic attributes in the largest regional commercial building stock in New Zealand. To that end, the Auckland Council proactively sought to assess thousands of commercial and industrial buildings across the Auckland region. As part of the Auckland Council program, a targeted sample out of a total of approximately 19,885 commercial buildings in the Auckland region was assessed with varying amounts of typological data recorded including lateral load resisting system type, number of stories, and time period of construction. Engineers, risk modelers, building regulators, and civil defense officials in other cities around the world can consider the Auckland Council program as a case study for how survey data may be collected, classified, and extrapolated to account for typological information not yet recorded as well as selection biases, and how relatively precise yet rapid assessments may be carried out for especially vulnerable building construction types and components.

This study presents an innovative procedure to derive the ultimate load capacity of a pile system by considering the natural (intrinsic) variability of a tropical soil. The tropical soil has high aluminum and iron content due to processes of lixiviation of the upper soil layers. As a consequence, this soil has a porous cemented structure, high void ratio, high permeability, and high variability of the geotechnical parameters in its depth. Soil layers are experimentally characterized via standard characterization, a triaxial test, standard penetration test, and flat dilatometer tests. Also, the load test of the standard groups (PG) and pile plus pile-cap (PC), which had self-drilling piles, were performed at real scale. Afterwards, simulations using a three-dimensional finite-element method (3D FEM) considering variations in soil parameters were performed for a hypothetical piles-plus-pile cap system under vertical loading using the random finite-element method. Mean parameters were verified through laboratory and field tests. Results from the load test simulations were compared with real-scale tests conducted in this study. The relative importance of variability of several geomechanical parameters was analyzed in terms of their effects on the contribution of the pile cap to the ultimate bearing capacity of the full system and found to be 18%; the minimum contribution is 2% of the total load. Finally, it is shown that reasonable savings in construction costs accompanied by a modest reduction in the safety factor ($\mathrm{FS}=1.8$) may occur when the variability of parameters is taken into account.

In this study, the variability inherent in the performance of RC frame structures to bridge over a column loss was investigated, considering the uncertainties existing in gravity loads, material properties, and construction geometries. Uncertainty and sensitivity analysis were conducted in tandem to provide the influence and significance of the uncertain parameters on RC frames to resist progressive collapse. Quasi-static pushdown analysis was used to assess the residual load-resisting capacity of structures with an initialized damage. A set of structural models were generated for uncertainty analysis by using the correlation-reduced Latin hypercube sampling method. Sensitivity analysis was performed by independently varying parameters with one standard deviation away from their means. Two typical RC frame structures with different span aspect ratios were taken as the study cases. The macromodeling technique, which was validated by the test results, was used for analysis. The study results indicated that structural uncertainties have significant effects on the behavior of RC frame buildings for mitigating progressive collapse caused by the loss of a ground column. Among the studied uncertain parameters, the gravity loads and the properties of reinforcement have the most effects on the residual load-resisting capacities of damaged frames.

Chloride-induced corrosion is one of the main causes of deterioration of reinforced concrete structures in marine environments. In the last decades many investigations have been concluded to determine the parameters affecting the deterioration of concrete structures. Prediction of long-term chloride penetration is necessary to be established based on the results of long-term exposure tests under a marine environment. This paper presents an experimental investigation for predicting long-term chloride content in concrete. The experimental results on specimens with 0%, 7.5%, and 12.5% silica fume (SF) and 10% natural zeolite (NZ) replacement, located in southern Iran for 7 years, showed that both the concrete cover and concrete quality requirements stated in the present codes need to be increased so that an acceptable service life can be achieved. Use of 0–12.5% SF and 10% NZ can reduce the required concrete cover thickness up to 20%–40% and 10%–20%, respectively. Also, the increase of water to cementitious material ratio from 0.40 to 0.50 can increase the cover depth up to 36%. In this regard practical graphs for design and analysis of concrete structures in marine environments have been derived based on long-term results of concrete samples in the investigating site.

This paper discusses three fundamental questions on the bridge deck-wave interaction: (1) are there countermeasures to mitigate the wave forces on the bridge decks? (2) what is the working mechanism of the countermeasures? and (3) what is the efficacy of such countermeasures? Motivated by these questions, a literature review is conducted and the air venting holes in the bridge deck slab is preliminarily identified to be a countermeasure for the bridge deck–wave interaction. To reach a deeper understanding of such a countermeasure, a solitary wave model is utilized here to carry on the numerical simulations. The shear stress transport (SST) $k\text{-}\omega$ model is considered as the turbulence closure for the Reynolds-averaged Navier–Stokes (RANS) equations to account for the turbulent bridge deck-wave interaction. Six different venting ratios for cases that the bottom of the bridge deck is at the still water level (SWL) are considered with detailed analysis of the characteristics of the air venting process, such as the pressure change in the chamber, the flow rate of the air and water through the air venting holes, and the force changes. Thereafter, different structure elevations, representing different submerging scenarios, with one target venting ratio are further studied. It is proven that this countermeasure is in favor of reducing the positive vertical (uplift) force substantially, but it results in an increase of the horizontal force correspondingly. This, in turn, requires more designing considerations for the supporting system to the bridge superstructures. This study will improve our understanding of this potential application in future engineering practices.

The rigid hanger is one of the main load-bearing components in a rigid tied-arch bridge that is common used in high-speed railway lines, and the mechanism for influences of train loads on the hangers’ transverse vibration -still requires clarification. This paper investigates the transverse vibration of rigid hangers in the rigid tied-arch bridge under train loads from three foci. Firstly, the accurate finite-element model of a rigid tied-arch bridge and the sub-model of each hanger of this bridge are established. The dynamic characteristics analysis of the whole bridge and each hanger are presented. Secondly, because the resonance theory used for stay cables and main girder cannot be used for rigid hangers in arch bridges, the hanger’s transverse vibration formula with consideration of the interaction of rigid hangers and main girder is proposed based on the classic structural dynamics. Thirdly, a simplified load model that can reflect the mechanical characteristics of high-speed rail Electric Multiple Units is established. The transverse dynamic displacements of hangers and their dynamic amplification factors in 6 field load cases are presented by nonlinear dynamic analysis; and also they have been validated based on the data from the structural health monitoring system. The conclusions show that generally the resonance between hangers and main girder is unlikely to happen in a rigid tied-arch bridge and the transverse dynamic displacement at long rigid hangers and the dynamic amplification factors of transverse dynamic displacements at short rigid hangers are required to be paid more attention; moreover, the parameters that affect the transverse vibration of hangers have been determined; finally, the geometry, cross sectional form, the spatial location of hangers and train speed can affect the transverse dynamic mechanical behavior of hangers. This work also gives a suggestion which lays a foundation for the better design, maintenance and long-term monitoring of hangers in a long-span rigid tied-arch bridge.

This article presents a proposed methodology to acquire optimum prestressing on diagonals in miter gates. The study uses three-dimensional (3D) numerical simulation of miter gates that includes all the geometrical details of the most commonly used miter gates. The simulation is used to attain vertical and lateral displacements at the miter end when the gate is mitered and in the operation for different prestressing forces. The simulation results allow the development of design curves that are used to obtain the optimum prestressing loading. These design curves can also be used to verify that the displacements of a gate are within tolerances for existing levels of prestressing. The analyses are compared with the existing criteria. The comparison shows that the miter gate leaf is not limited to only one prestressing combination, as prescribed by the design criteria, but several prestressing combinations evaluated from the numerical experiments can also provide the adequate torsional capacity. Furthermore, the study shows that the design criteria estimates a higher prestressing that likely causes a reduction in fatigue life in the diagonal connections. The new techniques will allow the prediction of optimum prestressing levels without compromising the torsional capacity.

Stone mastic asphalt (SMA) has been used for decades to extend the life of asphalt pavements, especially in terms of rutting resistance. However, its performance and cost-effectiveness have been debated. This study evaluates the long-term performance of an SMA pavement and its control hot-mix asphalt (HMA) pavement in eastern Washington State. The field performance of the SMA pavement and HMA control pavement was evaluated based on the data in a pavement management system and site visits. Field cores were extracted from both the SMA and HMA pavements and subjected to indirect tension (IDT) dynamic modulus tests, creep compliance tests, studded tire wear resistance tests, and intermediate and low temperature IDT fracture tests in the laboratory. SMA and HMA asphalt binders also were extracted, recovered, and subjected to performance grading, multiple stress and creep recovery tests, and monotonic tests. This study found that in the field, the SMA pavement outperformed the HMA pavement in terms of rutting and cracking resistance. Results of the laboratory tests of the field cores verified that the SMA material performed better than the control HMA material in terms of top-down, bottom-up, and thermal cracking resistance. Results of the recovered binder tests showed that the SMA mixture exhibited less aging than the HMA control mixture and that the recovered SMA binder provided better rutting, fatigue, and thermal cracking resistance than the HMA binder. Therefore, SMA pavements, when designed and constructed properly, are a viable solution for prolonging the life of asphalt pavement.

Performance-based road maintenance contracts (PBRMCs) are an effective mechanism to transfer risk and responsibility of road maintenance activities to the private sector. Proper structuring of performance indicators and the extent of penalties and incentives in the contract has a significant effect on the overall cost and level of service (LOS) provided to the public. This research develops a series of mathematical optimization models and a computational tool that allows road agencies and contractors to better structure the following contractual conditions in a performance-based contract (PBC) for road maintenance: (1) types of performance indicators to be considered; (2) their threshold levels; and (3) the appropriate levels of penalties and incentives. The availability of such models and tools will allow road agencies and contractors that are unfamiliar with PBRMCs to make informed decisions on their approach to contractual risk allocation. A case study of a major highway in Egypt is presented to demonstrate how slight changes in performance thresholds and contractual penalties affect the overall lifecycle costs (LCC) and eventual road performance. The results demonstrate that: (1) small variations in KPI thresholds can have a significant effect on the overall lifecycle costs and eventual contract price; and (2) the addition of penalties and incentives can be an effective mechanism to ensure contractors adhere to performance requirements in PBRMCs.

In many design codes, school buildings are classified as important structures. Hence, they are designed to withstand earthquakes with or without minor structural damage. This study examines the seismic performance of two aseismically designed regular reinforced concrete school buildings in Van, Turkey, after the October 23, 2011, earthquake. First, the results of reconnaissance studies regarding the seismic response of the school buildings are presented. These studies indicate that the selected buildings were moderately damaged. Three-dimensional analytical models of the buildings are developed to clarify their seismic response. The capacity values of the structures are calculated using the N2 nonlinear static procedure (where N stands for nonlinear analysis and 2 for two mathematical models). Afterwards, seismic performance of the selected buildings is assessed applying the procedures according to the latest design code. Nonlinear dynamic time history analyses are then carried out using data from the Muradiye monitoring station. The reasons of the observed damage are discussed. Further, recommendations are made to improve the seismic performance of aseismically designed reinforced concrete school buildings. The construction quality and detailing of the reinforcement are the major issues affecting the performance of school buildings.

Mitigation of blast effects caused by accidental explosions is one of the major challenges in structural engineering. Fiber-reinforced polymer (FRP) sandwich panels offer promising systems for blast mitigation applications due to their considerable energy absorption compared to other materials with similar density. The FRP sandwich panels can have different inner core configurations that can be filled with other materials whenever needed. This paper numerically evaluates the effectiveness of new FRP honeycomb sandwich panels in resisting blast loads. A numerical model has been created using nonlinear explicit finite element simulation. Then, the model has been validated using the experimental field tests in the literature. Twelve FRP panels with different inner core configurations have been proposed to enhance the panels’ performance by reducing their peak deformation and increasing their energy dissipation. The paper also investigates the effect of filling the FRP sandwich panels with sand on the panels’ blast resistance. The analyses have shown that the FRP panels utilizing the new core configurations are able to dissipate more than twice the energy compared to the experimental panels with even less deformations. It has been found that using sand as a filling material provides a damping medium that enhances the panels’ behavior under blast effect.

Low-rise, short-period buildings dominate the construction in the United States including residential, recreational, and critical, including hospital, facilities. Previous analytical studies have indicated that these structures behave poorly under seismic excitation compared to buildings with longer fundamental periods; however, such trend has not been observed in previous earthquake events. In this paper, a case study is considered to better evaluate the dynamic response of short-period light-frame wood buildings and help identify the modeling parameters and level of complexity required to accurately capture their dynamic response. For this purpose, a portion of the Twin Cities Community Hospital, located in Templeton, California (called herein the Templeton Hospital), was considered. This one-story light-frame wood building with a large roof diaphragm layout did not suffer any structural damage during the 2003 San Simeon earthquake despite being subjected to intense ground shaking. The Templeton Hospital was located at a distance of 38 km from the epicenter of the 2003 M6.5 San Simeon earthquake. The hospital structure was instrumented during this earthquake event, and recorded motions at various locations in the building are available in the public domain. Nonlinear numerical models of the selected portion of the Templeton Hospital building were developed in this study. These models incorporated varying levels of complex behaviors, so the influence of these behaviors on the level of correlation between predicted and recorded responses was assessed. Nonlinear response time history analyses were performed for each of the models developed under the ground motions recorded at the Templeton Hospital site during the 2003 San Simeon earthquake. Comparisons between predicted and recorded response time histories at various locations in the building were used to evaluate the effects of different levels of modeling complexity and to determine the minimum level of complexity needed to accurately reproduce the recorded data for this building. The results of this study indicated that the modeling of the in-plane diaphragm flexibility is the most crucial parameter needed to be accounted for in the analyses in order to accurately capture the observed response of this instrumented hospital during the San Simeon earthquake. It should be noted that the peak relative displacement measured for the Templeton Hospital was almost in the elastic range and, therefore, the findings of this study are focused on near-elastic response and not the full range of nonlinear response.

Buildings are exposed to multiple natural hazards over their service lives. Multihazard analysis and design of building structures has become a research hotspot worldwide. For these structures, earthquake and progressive collapse are two of the most commonly encountered hazards. However, little research has been conducted to examine the effects of the seismic and progressive collapse designs on the resistance of buildings against multiple hazards. In this study, a series of six-story reinforced concrete (RC) frames are considered, and their seismic and progressive collapse designs are performed independently according to the corresponding design codes. Fragility curves are used to assess the seismic and progressive collapse resistance. The interactions between the two designs are discussed by analyzing the fragility curves and the collapse modes. Results show that the progressive collapse design of the RC frame may lead to an undesirable failure mode (i.e., strong-beam-weak-column) under earthquakes, which indicates that a seismic redesign is necessary subsequent to the progressive collapse design. Note that sequential use of different design codes for a structure may result in material waste yet a suboptimal structural performance. Therefore, a design method by individually considering different hazards is unsuitable for the multihazard prevention and mitigation of building structures. A comprehensive and integrated design method for multihazards is thus in great need. The outcome of this study will lay a foundation for future multihazard analysis and design of building structures.

A 3-story building was found tilted badly as a result of a nearby deep excavation. Numerous cracks were developed on the façade walls and load-bearing brick walls. Dislodgement of some timber joists was observed at some parts of the second and third stories of the building. A detailed assessment of the conditions of the building was carried out. Unlike current prevailing practice, the assessment of damages caused by excavation-induced ground movements of this building includes tilts and out-of-plumbs of the load-bearing brick walls. The present study proposes to assume that the building behaves as a rigid body, and with appropriate empirical building correction factors to correct the inappropriateness of this assumption, reasonable estimates of the resulting out-of-plumbs of load-bearing brick walls of such buildings caused by a nearby deep excavation can be obtained. The empirically derived building correction factor is validated by comparing the predicted and measured out-of-plumbs of the brick wall of another 3-story masonry building affected by excavation. A new procedure for assessing damage potential to low-rise masonry buildings that includes tilt and out-of-plumb of brick walls caused by excavation is presented.

Facility managers are required to collect high-quality data to achieve corrective maintenance actions. Current facility management (FM) information systems are complex and provide high-quality data. However, they lack interoperability and visualization capabilities. The goal of this study is to improve the quality of data collected that is required for corrective maintenance by utilizing visualization and interoperability capabilities of building information modeling (BIM). To achieve that, an approach that implements industry foundation classes (IFC) BIM to link and present alarms reported by FM systems, such as building energy management systems (BEMS) and building automation systems (BAS), with related data from computerized maintenance management systems (CMMS) was developed and validated on a typical university building. The results showed an efficiency increase in high-quality maintenance data collection. The proposed approach supplements the existing body of knowledge in the FM domain by providing a schema that integrates corrective maintenance data in a three-dimensional (3D) IFC-BIM environment. Moreover, it provides a process to minimize the corrective maintenance lead-time and link equipment failures to the related maintenance information. FM practitioners can use this approach to decrease the lead-time needed corrective maintenance responses and focus their resources on productive maintenance tasks.

The relation between the soil-water characteristic curve (SWCC) and the soil freezing characteristic curve (SFCC) is investigated based on the similarity between the freezing/thawing and drying/wetting behaviors of soils. The SWCCs of clay and silt are obtained by the pressure plate extractor and vapor pressure method, while the SFCCs are determined from the unfrozen water content measurement using the nuclear magnetic resonance (NMR) and temperature measurement. The pore water potential of the frozen soil is derived from a generalized Clapeyron equation, which addresses the effects of capillarity, sorption, and osmosis, and compared to that of unsaturated soils. Our experimental results show that at low water content the matric potential in the soil saturated with pore water and pore ice is generally different from that in the soil saturated with pore water and pore gas. A series of experiments on the soil samples saturated by NaCl solutions of different concentrations were performed to determine the osmotic potential and the water retention characteristics. Based on the principles of surface chemistry, a relationship between the adsorptive forces and the water film thickness is developed, which is capable of describing the soil water characteristic when the sorption effect is significant. Our results indicate that the freezing-point depression method should be applied with caution in determining the soil water retention characteristics of unsaturated soils at lower water content.

Measuring water vapor sorption behavior has emerged as a potentially important alternative for characterizing expansive soil behavior. Mathematical models for representing measured water vapor sorption isotherms and for calculating properties such as heat of adsorption, monolayer coverage, and specific surface area (SSA), however, have not been evaluated in detail for clay-water systems. This paper evaluates fitting performance and correlations among four theoretical models previously developed for general sorbent-sorbate interactions (e.g., colloid science) for specific application to water vapor sorption on expansive clays. Models evaluated include those by Freundlich, Brunauer-Emmet-Teller, Frenkel-Halsey-Hill, and Guggenheim-Anderson-de Boer. Model performance is evaluated for a suite of bentonite-kaolinite mixtures representing a wide range of swelling potential and along adsorption and desorption paths. Trends in model parameters are evaluated as functions of bentonite content, correlated among the models, and discussed in the context of expansive soil characterization. Each model more accurately fits adsorption curves than desorption curves. Correlation is evident between bentonite fraction and model parameters reflecting sorption capacity, but is not evident between bentonite fraction and model parameters reflecting sorption strength. The SSA is systematically greater if determined from desorption isotherms rather than adsorption isotherms.

The demerits of level surveys for assessing foundation movements associated with moisture-induced volume change of soils have been well discussed and debated in the literature. In spite of the limitations of level surveys, and the associated strong desirability of benchmarked survey data for assessment of foundations movements on moisture sensitive soils, unbenchmarked level surveys continue to be used in forensic studies of buildings damaged by expansive and collapsible soils. The common uses and limitations of level survey data are briefly reviewed, and unbenchmarked level survey data are presented and discussed for three different cases of residential structures founded on collapsible and/or expansive clays. The level survey data are used, together with other available sources of information, in developing plausible explanations for building damage resulting from soil-wetting-induced differential movement of the structures.

Trees have long been known to cause damages to pavements and buildings as a result of soil desiccation by tree roots. This paper presents a case study of a residential house damaged by expansive soil movement caused by tree root drying. Daily transpiration and water uptake of a large Eucalypt tree, located 7 m from the northwest corner of the house, was monitored by using a sap flow meter. A numerical analysis was conducted to estimate the soil suction distribution and soil movement under influence of the tree. The measured soil suction profiles indicated that the large Eucalypt tree on the site had influenced the soil moisture condition to a depth of approximately 3.5 m, i.e., 1.5 m below the level of underpins. The case study revealed that the damage was most likely caused by tree root drying, and the differential foundation movements that had occurred after installation of underpins could be attributed to relatively shallow depth of underpins.

A large amount of construction waste creates problems related to cost and space for disposal, especially for countries with limited land like Singapore. Therefore, it is important to choose a suitable landfill management system (e.g., cover system) for optimization of landfill area in Singapore. In this paper, the performance of a cover system for minimizing rainwater infiltration into a sanitary landfill in Singapore is presented. The cover system was designed using principles of unsaturated soil mechanics. In this study, a residual soil from Old Alluvium with a low coefficient of unsaturated permeability was used in the cover system. Comprehensive geotechnical instrumentation was installed in the landfill area to monitor the pore-water pressure changes within the cover system and landfill during and after rainfall. Laboratory tests were conducted to characterize the index and engineering properties of the residual soil for the cover system under saturated and unsaturated conditions. The finite-element seepage analyses were carried out to study the effect of climate change on the soil cover system. The results from the seepage analyses showed good agreement with those obtained from the field measurements. The results also showed that the residual soil from Old Alluvium can be used as a landfill cover system to prevent rainwater infiltration into the waste material.

The paper presents the results of a case study to quantify the deterioration of a diamond-ground continuously reinforced concrete pavement (CRCP) surface in terms of macrotexture, skid resistance, ride quality, and pavement noise over time. The influence of site-specific features such as traffic speed and load, pretexturing prior to the grinding operation, lane, wheel path, and trafficking direction on the deterioration of the surface properties is considered. The four surface properties were measured before and immediately after the grinding operation and at three subsequent time intervals after 4, 9, and 15 months. Panel data analysis incorporating fixed effects was implemented to evaluate the influence of the site-specific features on the deterioration of the surface properties. The study provides statistical evidence of deterioration. A significant reduction in macrotexture and skid resistance was apparent. An increase in noise was evident soon after grinding. No significant change in roughness was found. The changes in the surface properties appear to be related to traffic over time but do not appear to be influenced by the pre-existing texturing prior to grinding. In summary, the diamond grinding of the studied CRCP pavement sections was not helpful to maintain the necessary skid resistance, texture, and pavement noise over the analysis period. However, diamond grinding was effective in maintaining a reduced roughness level and may be beneficial on any other CRCP pavements with harder aggregates.