Journal of Performance of Constructed Facilities

This paper provides a comprehensive summary of forensic research trends presented in the ASCE’s Journal of Performance of Constructed Facilities (JPCF). The paper reports the results of a 24-year analysis of JPCF published literature between 1987 and 2010. The Journal continues to serve as a primary resource for published literature in the field of engineering forensics and provides a recorded history of our recognition and understanding of important lessons learned. Interesting facts were revealed that provide insights for practitioners and academia alike. The investigation indicates a wide participation of engineering disciplines, an increasing number of new topics, innovations, and proactive forensic methodologies, extensive interdisciplinary collaboration, and a significant increase in international contributions. This study may serve as a basis for defining the history and breadth of forensic engineering and for understanding the international relevancy and regional interest in the diverse subject matter. Increased acceptance, dissemination, and participation in forensic engineering is evident and should be encouraged and sustained as part of engineering curricula, investigative research, and professional practice.

This paper presents the integral lifting and seismic isolation retrofit of the great hall of Nanjing Museum, a 78-year-old cultural and historical building. Due to the need for extension, the great hall of the Nanjing Museum needed to be lifted $3.0 \text{m}$. The total building area for lifting was $\mathrm{4,830} {\text{m}}^2$, with a total of 161 lifting points, which made this project quite challenging and also the largest done to date. Moreover, seismic isolation retrofit was utilized to improve the seismic performance of the translocated building. Details of the integral lifting and the seismic retrofit are presented in this paper, which include (1) the load underpinning system, (2) the spatial strengthening truss system, (3) the lifting control system, and (4) the base isolation using laminated rubber isolators. The entire lifting system performed well, and the main construction was finished within 5 months. Seismic time-history analyses were further performed to evaluate the effect of the seismic isolation. It was observed that the seismic responses of the museum were significantly reduced after retrofit.

In this study, the progressive collapse resistance of a two-story steel moment frame was investigated after the sudden removal of a perimeter column in the first floor through an experimental study. Two finite-element models with and without concrete slabs were developed and compared with the experimental results. The results indicate that the numerical model with slabs agrees well with that of the experiment and the concrete slabs play a significant role during the process of load redistribution. After the removal of the column, the partial loads previously carried by the removed column were transferred to its adjacent columns by the slabs. In addition, the concrete slabs and steel beams formed composite beams through shear connectors to resist the loads after the removal of the column. As a result, the stresses in the beams and the vertical displacements above the removed column were reduced significantly.

Experimental and analytical studies carried out on a RC moment-resisting frame after it is subjected to the loss of its ground-story exterior column is presented in this paper. Four full-scale interior beam-column subassemblages with varying degrees of nonseismic detailing were subjected to a monotonic loading regime to simulate the effects of redistributed gravity loads on the subassemblage after the loss of an exterior ground column. The variables in the test specimens include the beam longitudinal reinforcement ratios and the spacing of the transverse reinforcement within the beams, columns, and joints. The load-displacement relationships, crack development patterns, and failure mechanism obtained from the tests are also discussed. The finite-element models are validated by comparing the results with the experimentally obtained data. Parametric studies are then performed to study the influence factors, such as the beam transverse reinforcement ratio and the incorporation of an additional exterior beam-column element and slab on the global behavior of the subassemblages.

This paper studies the influence of slenderness on the behavior of steel-concrete composite columns encased in fiber-reinforced polymer (FRP) jackets. The composite columns are composed of steel I-sections that are partially encased by concrete and fully wrapped with epoxy-saturated glass and carbon FRP sheets. A total of nine specimens were tested with different slenderness parameters and heights ranging between 500 and 3,000 mm. The confining pressure provided by the FRP jacket and the composite action between the constituent materials resulted in an enhanced compressive behavior of the composite columns. The compressive strength, elastic axial stiffness, and energy dissipation capacity of the composite columns increased by a ratio of up to 5.2, 2.5, and 14.0, respectively, compared with that of the bare steel columns counterparts. A capacity curve, which shows the compressive strength of the composite columns for various slenderness parameters, was developed based on the experimental results.

In this study, the dynamic response of typical wide-flange steel beams was experimentally evaluated under blast loading. A total of 13 beams were field tested using live explosives, where the charge size ranged from 50 to 250 kg of ammonium nitrate-fuel oil mixture, and the ground stand-off distance was from 7.0 to 10.3 m. Blast wave characteristics, including incident and reflected pressures, were recorded. In addition, time-dependent displacements, accelerations, and strains at different locations along the steel members were measured, and the postblast damage and mode of failure of the test specimens were observed. The blast load characteristics were compared with those obtained using the Technical Manual UFC 3-340-02 results. The displacement response results were used to validate the results obtained from a nonlinear dynamic analysis based on a single degree-of-freedom (SDOF) model. Results showed that the UFC 3-340-02 pressure predictions compare reasonably well with the measured pressure in the positive phase in terms of both the peak pressure and overall time variations. The SDOF model predicted the maximum displacements of beams in the elastic range reasonably well, but it overestimated them in the plastic range.

Annoying floor vibrations, a growing issue in today’s world of lighter structural members and low inherent damping because of modern office fit-outs, may also be significant in open web steel joist supported floor systems. In the presence of these vibrations, sometimes bottom chord extensions are installed in an attempt to stiffen the floor and correct the annoying vibrations problem. This study focuses on the effect of bottom chord extensions on the static flexural stiffness of joists under relatively light loads associated with occupant-induced floor vibrations. Extensive analytical and experimental studies were conducted on single-span and three-span joist-supported laboratory footbridges with different bottom chord extension configurations. Three-dimensional finite-element computer models were created to simulate and compare the results of the stiffness tests. Testing was done with (1) the bottom chord extensions installed prior to concrete placement, (2) all or part of the bottom chord extensions removed, and (3) the bottom chord extensions reinstalled with jacking for the single-span footbridge and without jacking for the three-span footbridge. The primary objective was to determine the possible increase in flexural stiffness when bottom chord extensions are installed in an attempt to reduce annoying floor vibrations. The experimental results for the two footbridges with bottom chord extensions installed after the concrete placement are compared with results when the bottom chord extensions are installed prior to concrete placement and to footbridges without bottom chord extensions. Results from the stiffness tests on a single-span footbridge indicate that installing the bottom chord extensions to the joists after concrete placement and with the center of the span jacked up increases the flexural stiffness considerably, but not as much as installing the bottom chord extensions before the concrete placement. Similar results were found when bottom chord extensions were installed after concrete placement but without jacking on a three-span footbridge. The magnitude of the increases in flexural stiffness was sufficient to consider the installation of bottom chord extensions as a remedy to stiffen a floor and reduce floor vibrations because of occupancy movements.

A detailed investigation was carried out on a 50-year-old reinforced concrete jetty in a commercial port of Iran to assess the long-term performance as well as the structural condition. Destructive and nondestructive tests such as carbonation depth, electrical resistivity, chloride diffusion, X-ray diffraction, compressive strength, and water absorption were performed. The results revealed that the good quality of the concrete has protected reinforcement from corrosion. However, structural analysis showed minor weakness in some elements of the jetty; thus, consulting engineers finally decided to strengthen some elements with fiber-reinforced polymers.

Taquezal is a common earthen building type in Nicaragua. It is constructed by building a wood frame and then packing the frame with mud to create thick earthen walls. The wood frame allows the structure to be constructed without the formwork (which is required for rammed earth buildings) and without first constructing blocks (which is generally required in adobe construction). The wood frame also allows a thinner wall than other earthen building types. Commonly, taquezal roofs are made of timber framing and heavy clay tile roofs. Taquezal buildings are not engineered and therefore are difficult to analyze with modern structural engineering methods. During the 1972 Managua earthquake, nearly 10,000 people died, and most of them were in taquezal buildings. This paper discusses taquezal as a structural system and applies engineering methods to this nonengineered structure. It was found that taquezal buildings perform well during low-to-moderate earthquakes if well maintained. However, if the wood is not maintained and allowed to rot, this degrades the roof diaphragm and wall supports, and the performance is considerably diminished.

The placement of an asphalt overlay is the most common method to rehabilitate existing concrete pavements. Reflective cracking, however, has been a serious problem with asphalt overlays for a long time. To prevent reflective cracking, it is critical to evaluate existing concrete pavements and identify the joints/cracks with poor load-transfer efficiency (LTE) before placing an asphalt overlay. The most common equipment for this evaluation is a falling weight deflectometer (FWD). However, FWD testing is conducted only at discrete points and is time consuming. It is desirable to use the rolling dynamic deflectometer (RDD) that can continuously characterize each slab and all joints and cracks (e.g., LTE). The RDD was developed in the 1990s at the Center for Transportation Research in Austin, Texas. The RDD is one of the few operational rolling deflection systems that provide continuous data to make project level decisions on rehabilitating concrete pavements. In contrast to the FWD, no RDD data analysis software is available. This paper discusses RDD data interpretation and its application on evaluating existing concrete pavement for asphalt overlays. First of all, some basics of RDD deflection data interpretation are discussed. Several common patterns within the RDD data are identified, and associated interpretation and limited verification are presented in this paper. The RDD deflection data measured before an asphalt overlay on Interstate Highway-20, Texas, and the observed asphalt overlay performance (in terms of reflective cracking) are then presented, and the relationship between RDD deflection and reflective cracking rate is further investigated. Finally, guidelines for evaluating existing concrete pavements using RDD are proposed.

This paper presents a forensic investigation of selected Arizona specific pavement study (SPS) SPS-5 test sections. The investigation focused on identifying the causes of pavement failures, examining the pavement structural and functional performances, and measuring within-section layer thicknesses and material properties. In addition, the investigation addressed the potential effects of overlay thickness and overlay materials used (recycled and virgin asphalt) and the extent of surface preparation (minimum and intensive) on pavement performance. Destructive and nondestructive tests were conducted following the long-term pavement performance (LTPP) program test protocols. The main pavement distresses identified in the test sections included fatigue cracking, longitudinal cracking, transverse cracking, rutting, block cracking, and pumping. Based on the observations of the coring and trenching operations, most of the cracks were top-down cracks exhibiting high severity at the top and low severity at the bottom of the layer. Wheelpath rutting was observed in the overlay layer only, and virtually no rutting was detected in the lower layers. The maintenance activities (fog seals and crack sealing) applied over the years appeared to have reduced the propagation of fatigue and transverse cracks temporarily and did not significantly improve the postrehabilitation structural performance. While all sections performed well compared with the virgin asphalt overlay, the recycled overlay test sections exhibited the largest postrehabilitation rate of increase in roughness and rutting (with thinner overlays) over their monitoring period. Pavement deterioration was not associated with the base and subgrade layers. The extent of distress was also found to be associated with high binder content and air voids.

To ensure the safety of adjacent 16.7-m-high concrete frame structures (cooling towers) and buried pipelines in service during installation of 83 prestressed high-strength concrete (PHC) pipe piles, the behavior of the ground, the buried pipelines, and cooling towers was monitored by a comprehensive instrumentation program. The field measurements included the following: (1) time histories of the particle velocities and corresponding Fourier spectra in three mutually perpendicular directions at various pile penetration depths and (2) vertical and horizontal movements of the buried pipelines caused by pile installation. Based on the analysis of the field data, the following major findings were obtained: (1) unlike the driving of prestressed concrete piles or cast in situ piles, the vibration velocity in the vertical direction was not greater than that in the plane during PHC pipe pile driving; (2) the amplitudes of the peak particle velocities were relatively independent of the pile penetration depths because of the complex soil conditions; (3) both the ground and the concrete structure experienced primarily high-frequency vibrations, which attenuated rapidly over time; (4) during the pile driving, only slight vibration amplification was observed at the upper levels of the existing concrete frame structure as a result of the soil-structure interaction—the concrete structure had a much wider frequency band (around 0–300 Hz) than the ground (around 0–100 Hz); and (5) the method of installing the piles close to the existing facilities before installing those a distance away effectively mitigated the potential adverse effects on the buried pipelines.

The threat of terrorist attacks on subway systems using explosives has intensified considerably in recent years. Explosions inside subway tunnels may lead to the failure of subway structures and result in further socioeconomic losses. Specifically, the century-old, single-track, cast-iron subway tunnels in cities such as New York and London are very vulnerable to this type of attack. In this study, an explicit dynamic finite-element procedure was developed to carry out extensive numerical simulation to investigate the soil-structure interaction and failure of cast-iron tunnels in saturated soils subject to internal explosions using the medium amount of explosives (80 kg TNT) that might be perpetrated by terrorists. The stress path and damage mode of these tunnels, subjected to internal blast loading, were first investigated based on the simulated damage of cast-iron tunnel lining using a hardening elastoplastic model that considered shear damage. The study aims to better understand the soil-structure interaction and its relation to lining damage of cast-iron subway tunnels under internal blast and to investigate the influences of several critical parameters on lining failure, including compressibility of saturated soil, brittleness of lining materials, specific impulse of blast, and strength of the soil-lining interface. The study found that ground-tunnel interaction was one of the governing factors that determined the damage of tunnel lining under medium internal blast loading by providing the necessary confinement to resist internal blast loading and by absorbing blast energy with its plastic shear deformation. Lining damage was mainly triggered by the tensile hoop stress because of large inertia and dynamic forces in the radial direction of the tunnel, and it may exhibit a progressive pattern in the vibration phase. Soil compression significantly influenced the damage of the tunnel under internal blast loading. The damage was more severe with compressible saturated ground.

Behavioral, managerial, and technical problems cause construction injury accidents. Among these accidents, cave-ins are some of the most frequently occurring accidents. Mitigating hazards that result in cave-ins are of great importance in managing and controlling excavation practices. This paper introduces a new conceptual risk mitigation tool that can be adopted to minimize cave-in hazards and be employed as a quality-control tool before and during excavations. It provides a list of hazards in ranked order from the most frequent to least frequent and most hazardous to least hazardous causes that managers should focus on and invest resources into. Precise risk evaluation for cave-ins using traditional methods of failure mode and effect analysis (FMEA) can be challenging, because the variables involved in cave-ins are unique, and historical data are often incomplete. In construction, estimation of risk is based on severity, frequency of occurrence, and likelihood of detection; management teams assess these factors prior to failure occurrences using subjective judgment expressed by linguistic values, such as severe and very likely. Such linguistic terms can be best modeled using the fuzzy set theory. The traditional FMEA method has been widely used to calculate a risk priority number (RPN), which is a weighted assessment used to prioritize risk items. The calculation of the RPN is based on the rating of three variables: (1) severity, (2) frequency of occurrence, and (3) likelihood of detection. The traditional RPN is the product of these variables. Implementation of the FMEA for construction projects must be modified, because calculation of the RPN in construction projects is based on managerial experience using experiential, subjective expressions. The RPN is substituted for fuzzy rating calculation using alpha cuts and fuzzy arithmetic, in order to perform the fuzzy operations of the variables and to introduce a workable model of a fuzzy risk priority number (FRPN). For assessment purposes, the FRPNs are ranked. A numerical example is provided to illustrate the potential application of the proposed fuzzy failure mode effect analysis (FFMEA) and the detailed computational process of the FRPN. An application of the FFMEA is presented for the assessment of construction trenching safety risk. The FFMEA method introduced is intended to be used for (1) anticipating potential cave-in accidents prior to their occurrence; (2) assessing risks associated with excavation work; (3) providing a list of likely cave-in accident scenarios associated with excavation work in advance; and (4) preparing solutions and taking corrective actions before cave-in accidents occur.

In this study, the contribution of horizontal bracing to the resistance of a steel moment frame against progressive collapse was investigated using the alternate path method. Nonlinear dynamic analyses of two frame models with and without horizontal braces were carried out in various cases. The dynamic nonlinear analytical results indicated that compared with the model without braces, the displacements and rotation angles in the model with horizontal braces were much smaller because of the horizontal tie provided by the horizontal braces at the top story. It was observed that the horizontal braces could transfer the vertical loads originally carried by the removed column to the adjacent columns. Also, the layout of the horizontal braces was an effective means to enhance the resistance of the steel moment frame.