Journal of Performance of Constructed Facilities

The objective of this study was to develop and validate practical modeling methods for investigating load paths and system behavior in a realistic light-frame wood structure. The modeling methods were validated against full-scale tests on subassemblies and an L-shaped house. The model of the L-shaped house was then modified and used to investigate the effects of reentrant corners, wall openings, and gable-end retrofits on system behavior and load paths. Results showed that the effects of adding reentrant corners and wall openings on uplift load distributions were dependent on the orientation of the trusses with respect to the walls. Openings added to walls parallel to the trusses have the least effect on loads carried by the remaining walls in the building. Varying reentrant corner dimensions under design wind loads caused increasing degrees of torsion throughout the house depending on the relative location and stiffness of the in-plane walls (parallel to the wind loads) and the assumed direction of the wind loads. Balancing the stiffness of the walls on either side of the house with the largest reentrant corner helped to decrease torsion in the structure under lateral loads. Finally, although previous full-scale tests on gable-end sections verified the effectiveness of the gable-end retrofit that was recently adopted into recent Florida building code, questions remained about the effects of the retrofit on torsion in a full building. The current study found that adding the gable-end retrofits to the L-shaped house did not cause additional torsion.

Current methodologies of fire origin investigation have yet to include the structural deformations witnessed in steel buildings as a viable indicator of the area of fire origin. In this paper, the validity of using such a technique for fire investigation has been assessed. A series of full-scale burn tests was conducted to validate the proposed methodology. Although it did not turn out that the greatest magnitude of deflection was always indicative of the precise area of origin, the tests have shown that the deflections can be used as important indicators of the area of origin.

The irregular shape of three large balconies in a performing arts center resulted in areas at the balcony tip and edge susceptible to potentially annoying levels of vibration. To mitigate this effect, the building designers added tuned mass dampers to the underside of each of the three balconies. Proper implementation of tuned mass dampers requires reliable information about the dynamic properties of the structural system. Finite-element models of the structure were constructed and experimentally verified. These models were used to determine the size, frequency, and damping ratio of three tuned mass dampers, two of which targeted the first bending mode of the edge and the remaining one targeted the first bending mode of the tip, for each balcony. The suspensions of the tuned mass dampers were made up of two laminar flow viscous damping units along with eight precompressed helical steel springs. The mass of the tuned dampers were selected as a small percentage of the modal mass of the modes targeted for damping. On completion of the tuned mass dampers installation, the effectiveness of the damping solution was evaluated via further testing.

The effects of human-structure interaction on the dynamic performance of occupied structures have long been observed. The inclusion of the effects of human-structure interaction is important to ensure that the dynamic response of a structure is not overestimated. Previous observations, both in service and in the laboratory, have yielded results indicating that the effects are dependent on the natural frequency of the structure, the posture of the occupants, and the mass ratio of the occupants to the structure. These results are noteworthy, but are limited in their application,because the data are sparse and are only pertinent to a specific set of characteristics identified in a given study. To examine these characteristics simultaneously and consistently, an experimental test structure was designed with variable properties to replicate a variety of configurations within a controlled setting focusing on the effects of passive occupants. Experimental modal analysis techniques were employed to both the empty and occupied conditions of the structure and the dynamic properties associated with each condition were compared. Results similar to previous investigations were observed, including both an increase and a decrease in natural frequency of the occupied structure with respect to the empty structure, as well as the identification of a second mode of vibration. The damping of the combined system was higher for all configurations. Overall, this study provides a broad data set representing a wide array of configurations. The experimental results of this study were used to assess current recommendations for the dynamic properties of a crowd to analytically predict the effects of human-structure interaction. The experimental results were used to select a set of properties for passive, standing occupants and develop a new model that can more accurately represent the behavior of the human-structure system as experimentally measured in this study.

Two major earthquakes with magnitudes $M_w=7.2$ ($M_L=6.7$) and $M_L=5.6$ occurred in eastern Turkey on October 23 and November 19, 2011. The maximum measured peak ground accelerations for the two ground motions were 0.18g and 0.25g, respectively. The earthquakes resulted in various levels of damage to RC moment-resisting frame buildings ranging from minor cracking in brick partition walls to total collapse. This paper summarizes the field observations of the Atilim University Reconnaissance Team carried out in the region a few days after the two main shocks with an emphasis on the performance of RC buildings. A summary of the evolution of the Turkish seismic design code during the last 35 years is given, followed by an explanation of the behavior of RC buildings during the October 23 and November 9 earthquakes. The deformation types that were commonly observed in the heavily damaged or collapsed RC buildings include plastic hinging in columns attributable to stiffer beams, localization of damage in ground-story columns attributable to changes in the stiffness of the lateral load-resisting system caused by brick partition walls, and shear failure of columns caused by discontinuities in the partition walls adjacent to the columns. Poor concrete quality, inadequate development and lap splice length for reinforcement, and inadequate confinement in columns also contributed to the poor seismic behavior.

Understanding the damage and failure mechanisms of masonry structures can help engineers reduce catastrophic failures and facilitate effective restoration and preservation of historical masonry monuments. This can be achieved through a combination of experimental and numerical studies to gain insights on the macrolevel strength-deformation behavior and microlevel defects and crack growth of masonry structures. Although experiments aid in calibration and validation of the numerical model to reduce errors and uncertainties in predictions, the success of the simulations fundamentally depends on the accuracy of the mechanical principles used to represent the heterogeneous masonry assembly. In this paper, three modeling techniques—detailed micromodeling, simplified micromodeling, and macromodeling—are investigated, considering not only the accuracy but also the robustness of the model predictions. In detailed micromodeling, the brick units and mortar joints are modeled as separate entities. In simplified micromodeling, the bricks and mortar are smeared, homogenized units bonded with zero-thickness interface elements. In macromodeling, the masonry composites are smeared into a homogenous continuum. Linear properties of these three alternative models are first calibrated by exploiting the modal parameters identified through dynamic experiments conducted on a scaled dome specimen in the laboratory. The fidelity of the two micromodeling and the macromodeling techniques are then evaluated by comparing the model predictions against static, load-to-failure tests conducted on the same scaled masonry dome. Finally, the robustness of the three models to uncertainty in the input parameters is evaluated.

The Palazzo Lombardia Tower, located at the heart of the city of Milan, Italy, recently was completed. At 161.30 m high, the new building is currently the tallest in Italy and one of the most prominent features of the city skyline for many years to come. Given the strategic importance and the strong impact of the new building, it was decided to perform a series of dynamic excitation tests, with special emphasis on the Tower. Thus, it was possible to estimate its basic modal features and then compare them to the numerical simulation predictions provided by the same finite-element (FE) numerical analysis used for design. This offered the chance to start an important and interesting model-updating procedure, taking advantage of both the actual material properties measured during the construction phase and dynamic measurements, the latter having added significant insight to the structural behavior. The mechanical engineering department of the Polytechnic University of Milan was in charge of the design and execution of the tests. Professor F. Mola served as the structural designer of the building and also supervised the design and interpretation of the tests, together with the staff of ECSD Engineering and CAD DataConsult, who created the analytical model of the complete structure to be used as a benchmark for the experimental results. The tests provided an experimental validation of the modeling assumptions accuracy and of the robustness and reliability of the FE model in predicting the structural behavior. Moreover, the experimental validation of the FE model of the Tower was meant as the initial part of an intended continuous monitoring activity. This paper describes the main structural features of the Palazzo Lombardia Tower and those of the experimental tests. Also, the FE model is presented and the comparison between the numerically predicted and the experimentally derived modal properties is discussed.

UNESCO has designated the archaeological sites of Persepolis and Naghsh-e-Rostam as cultural world heritage sites. These sites are located at 55 km northeast of Shiraz, in southern Iran. Persepolis consists of three parts: the Platform, the Southern Barzan, and the Northern Barzan. The Sivand River, which flows near these archaeological sites, is historically known as a severe flood river. This study investigates the possible inundation of the Persepolis and Naghsh-e-Rostam regions under extreme floods of the Sivand River. The 10,000-year return period flood and peak flow of probable maximum flood are estimated to be $\mathrm{2,717}\hspace{0.17em}\text{and}\hspace{0.17em}\mathrm{7,862}\hspace{0.17em}{\text{m}}^3/\text{s}$, respectively, at a station near these sites. The Hydrologic Engineering Center River Analysis System (HEC-RAS) model was then used to simulate the potential inundated downstream area with the estimated flow rate of a 10,000-year return period flood and the probable maximum flood. The model showed no risks of inundation by 10,000-year return period flood, but the probable maximum flood can potentially submerge the Southern Barzan and some parts of the Platform. The archaeological sites must be protected from any damage during the time span of human life; therefore, it is recommended that all of the archaeological sites be studied for extreme floods as a routine procedure.

Design audits have been identified as an effective mechanism for reducing errors and the subsequent rework that can arise during the construction process. Despite their effectiveness, errors and rework remain problematic issues as a result of ineffective audit protocols and systems. Drawing on experiences from Hong Kong, a triangulated research approach is adopted to examine how design audits can be effectively used to reduce errors and rework. With increasing schedule and fee pressures being imposed upon construction and engineering firms by their clients, it is vital that engineering firms do not eschew tasks associated with the auditing process to ameliorate efficiency and maximize fees. The rework associated with addressing errors during construction not only increases project costs and the schedule, but also reduces an engineering firm’s profit and reputation. A systemic audit system for construction projects derived from experiences in Hong Kong, and which may also be considered in other countries, is presented.

The statistical characteristics of design error rectification costs experienced in 139 Australian construction projects are analyzed. Theoretical probability distributions are fitted to the design error cost data. A generalized Pareto probability function was found to provide the best overall distribution fit for design error costs. The generalized Pareto distribution is used to calculate the probability of design error costs being experienced for the selected sample. A mean design error cost of 14.2% of a project’s contract value is reported. A significant difference between mean design error costs and project types was found for civil engineering (23.44%) and fit-out (22.50%) projects. Projects $>$Australian dollars (A$)101M were found to experience significantly higher mean design error costs (26.18%) than other projects. Being able to determine the likelihood of design error rectification costs from the derived empirical probability distribution will provide an ameliorated assessment of risk before the commencement of construction. Strategies to reduce design error rectification costs are also discussed.

Accurate performance assessment of building systems and subsystems (e.g., roof, boiler, windows, etc.) is essential to properly prioritize the subsystems that compete for capital renewal funding. Typically, the performance assessment of buildings has been based on physical condition alone, which is not sufficient for specialized facilities such as hospitals. This paper introduces a practical multicriteria performance assessment framework for hospitals with four unique features: (1) it divides the hospital into three zones with different characteristics and importance: clinical, nursing, and support; (2) it assesses the performance of hospital subsystems, considering four key performance indicators: condition, level of service, sustainability, and risk; (3) it assesses the service quality (temperature, lighting, noise, etc.) within various indoor spaces and accordingly determines the level of service of related subsystems; and (4) it incorporates a simple all-on-site visual inspection application that automatically computes the subsystems’ overall priority indexes. A survey among hospital maintenance experts was used to collect data for the design and verification of the proposed framework. This paper discusses the framework design and its benefits in improving the performance assessments of hospitals.

Buildings and related civil infrastructure are an important factor of production that contribute directly to the accomplishment of an organization’s mission and/or the generation of revenue. Aging, obsolescence, and general deterioration of these buildings, and their systems and components, can adversely affect the ability to accomplish a mission or generate expected revenue, thus resulting in an elevated risk profile. Maintenance, repair, and renovation (MR&R) activities, when planned effectively, can affect performance in such a way to reduce this risk. A rapidly aging infrastructure and building stock in the United States and across the world jeopardizes the ability to generate output and accomplish a mission at status quo. Moreover, rapidly expanding demands on some infrastructure will likewise make the status quo greatly inadequate in the near future. This requires two highly interrelated strategies: (1) to introduce new capabilities and capacities into the infrastructure stock to meet projected demand; and (2) to adequately manage, maintain, improve, and renew the existing infrastructure stock to slow performance degradation and fill demand gaps. The objective of this study is to develop a methodology for rapidly identifying and selecting multiyear building MR&R activities, such that facility performance is maximized and life cycle costs are minimized. This is a significant step toward the development of a comprehensive facility life cycle MR&R model that incorporates infrastructure economics and uncertainty for improved decision making. The result of this study is a model framework, to be applied against a building or group of buildings, which selects the optimum mixture of work activities considering condition, capability, performance, and life cycle costs. A genetic algorithm is employed to optimize the activity selection, and the proposed model approach is implemented against an example building to illustrate the methodology.

The structural behavior of steel tied-arch bridges is determined by the presence of a large compressive force. As a consequence, slender steel arches are highly sensitive to in-plane as well as out-of-plane buckling. At present, no specific buckling curves for out-of-plane buckling exist for nonlinear or curved elements in the international codes and calculation methods. This research is mainly concerned with quantifying the geometric imperfections of real arch bridges based on the results of on-site strain measurements. The arches of six bridges have been equipped with strain gauges along their entire length. For the actual determination of the imperfections, a detailed finite-element model has been developed. It is assumed that the actual geometric imperfections are a linear combination of a number of theoretical imperfections. These imperfections are characterized by a theoretical lateral displacement in a single cross section of the arch. The influence of these theoretical imperfections can be calculated using the described finite-element models. The actual imperfections are determined based on the comparison of measured strain values with the strain values based on a linear combination of theoretical imperfections. This method is verified using the results of topographical measurements of one of the studied bridges. Both sets of results are in agreement when it comes to size and shape of the imperfections. The shape of the resulting geometric imperfection is a half-sine wave for most of the studied bridges. However, the most important result is that for all considered bridges, the size of the imperfections is substantially smaller than the one predicted by design codes.

A new steel-concrete connection with Perfo-Bond Strip (PBL) connectors for a hybrid cable-stayed bridge was adopted and introduced. Push-out tests of the PBL connectors were performed to evaluate the shear capacity of perfobond ribs in steel-concrete connections. Test results revealed that the shear strength of a perfobond rib in a twin configuration is about 80% of that of a single independent perfobond rib. To investigate the safety and reliability of the proposed connection from a practical perspective, a model test with a scale of 1:2 for the joint of the hybrid girder was carried out on site. During the test, stress distribution, crack resistance ability, and relative slip between concrete and steel were measured carefully to investigate the mechanical performance, force transmission, strength, and stiffness of the steel-concrete connection. The test results revealed that concentrated stress at the loading section in steel girders can be reduced and transferred uniformly through the joint to the concrete sections by a combined axial and shear force transmission mode with the help of bearing plate and multiple parallel perfobond ribs. The findings from the tests and analyses are considered to be of special significance to the design and construction of steel-concrete connections in hybrid cable-stayed bridges.

Damage to skewed bridges in recent earthquakes has reinforced the potential vulnerability of these structures. The effect of skew angle on a bridge’s fragility could vary for different bridge types, ages, or geometric configurations. This paper conducts a probabilistic seismic assessment of skewed bridge performance, focusing on single-frame concrete box-girder bridge subclasses. The effect of skew angle on bridge seismic fragility is investigated for bridges with single- or two-column bents, integral or seat-type abutments, and minimal or significant levels of seismic design. Component and system-level damage states consistent with HAZUS-MH definitions are also explored in this study. The results reveal that older bridges, which are more likely to experience higher damage states, are particularly susceptible to column damage and are not sensitive to skew. Similarly, the presence of integral abutments in newer bridges significantly reduces the vulnerability and minimizes the impact of the skew angle on bridge fragility. For new bridges with seat-type abutments, the bridge skew angle has a significant effect on component and system fragility for both single- and two-column bent bridges. For these subclasses, HAZUS-MH skew factors are found to reasonably estimate the shift in median value fragility from their straight counterparts.

As part of a study to quantify temperature effects on integral-abutment box-girder bridges, field instrumentation was monitored continuously for one year on a bridge near Sacramento, California. Thermocouples were installed throughout the deck as well as over the height of the superstructure. Temperature changes were used to obtain maximum and minimum average temperatures as well as positive and negative thermal gradients. These values were compared with recommended respective temperature ranges. Strain changes at various locations were obtained by driving trucks along five load paths. These data, along with strain changes resulting from daily temperature variations, were used to validate a finite-element model using solid elements for the superstructure and springs at the abutments, in order to replicate the partial fixity of the bridge. The validated finite-element model was used to evaluate the effects that the partial fixity and temperature gradients have on the temperature stress for a typical integral-abutment bridge.

Micropiles, which are small-diameter, drilled piles, are being used more frequently to support structures where it is not feasible to use driven piles or larger-diameter, drilled shafts because of conditions such as limited overhead or restraints on vibrations. The construction procedures used for micropiles typically include the performance of verification load tests (i.e., compression load tests to 2.5 times the design capacity on test piles) and the performance of proof tests (i.e., load tests on a limited number of production piles, typically about 5%, to 1.67 times the design capacity). Because of concerns over postconstruction settlement and the difficulty of proof loading individual production piles to 1.67 times the design capacity, all production micropiles used to underpin four bridges were preloaded, and the deflection of each pile was measured to verify acceptable postconstruction performance. The collection of deflection data for such a large number of production micropiles is unusual and serves as a valuable case study showing the successful performance of drilled micropiles.

Some rural water supply (RWS) schemes were constructed in 2002 in the Dhule district of Maharashtra State in India as part of pilot projects launched in 68 districts throughout the country with financial assistance from the Government of India. The present research is derived from an investigation conducted on 11 such RWS schemes constructed during the period of 2002–2005 and aims to establish a composite sustainable management index for assessing long-term sustainability in the context of the level of service and evaluating the current performance level of piped-water supply schemes. The identification of factors influencing sustainable management is a prerequisite for developing a composite index. Various investigators have worked on the sustainability of RWS systems worldwide considering different sets of factors and subfactors. In this research, a set of five factors and 25 subfactors is considered. Two factors, though being a part of functional sustainability, are excluded in building the index; however, they are used to validate the results. The analytical hierarchy process is used for the development of metrics in decision making, i.e., for establishing the weight of factors and subfactors. The proposed model enables RWS utilities to identify the key sustainable management factors and provides a framework for aggregating various factors and subfactors into a composite sustainable management index. The outcome may also be used to identify the factors/subfactors that have potential for improvement and thus be helpful in finalizing the strategies for enhancing the functional sustainability of the system. The results demonstrate that nine subfactors out of the 25 dominate in all 11 RWS utilities studied. The RWS utilities are classified on the basis of their performance as high, moderate, or low in sustainability. The derived factors’ sustainability index may be useful for decision makers to discover the tradeoffs between them. The derived index may be a rational and transparent basis for recommending postconstruction support for a rural water utility. The limitations of the presented research are the comprehensiveness and effectiveness of the data considered, being slightly biased to the accessibility of information, in the absence of a more rational data-recording system.

Prestressed concrete cylinder pipe (PCCP) is a large-diameter and high-strength pipe used in water or wastewater transmission mains. It has been widely used in North America because of its good performance, large capacity, and cost-effective price. However, some PCCPs fail after a certain time of service because of deterioration. PCCP failures can be very significant considering the pipe size and high internal pressure. To mitigate the serious results of PCCP failures, many condition assessment technologies have been developed to inspect the pipe condition, and many models have been developed to predict the performance of the pipe. These technologies and performance prediction methods have been used as reference for decision-making in PCCP pipeline management. However, because of their limitations, there is still a strong need to improve them for better application in the future. This paper, by using three databases, presents a state-of-the-art literature review of the most commonly used condition assessment technologies and performance prediction methods for PCCP. The objective of this research is to analyze the capabilities and limitations of current condition assessment technologies and performance prediction methods and to propose direction for future research on PCCP by considering its failure factors, modes, and mechanisms.