Journal of Performance of Constructed Facilities

This paper investigates the contribution of unreinforced masonry infill panels to the robustness of composite steel framed buildings subject to sudden column loss. A previously developed multilevel robustness assessment approach is extended and used to establish the system pseudostatic capacity, which determines the level of gravity loading that could be sustained under sudden column loss without exceeding the system ductility limit. The infill panels are modeled according to the ultimate failure mode and confinement caused by the frame, where a simplified approach is proposed based on extracting the infill panel contribution in isolation of the surrounding frame. The developed modeling approach is applied to a 7-story building, where it is shown that accounting for infill panels can increase the structural resistance to sudden column loss significantly, thus avoiding disproportionate collapse in most cases.

Corrosion of reinforcing bars is a common deficiency for existing RC buildings, which may have significant adverse effects on seismic performance of those buildings. The main effects of corrosion of reinforcing bars are strength loss as a result of reduction of the effective cross-sectional area of the bars, reduced bond strength between concrete and bars as a result of the increased volume of the bars because of rust products, and reduced elongation capacity of the bars as a result of the concentration of plastic deformations at sections of corrosion pits. The last item (concentration of plastic deformations of reinforcing bars only at the most heavily corroded sections rather than occurring all through the potential plastic hinge length) has a very remarkable adverse effect on the displacement capacity of existing buildings. It is known that the displacement capacity is as important as strength, particularly for the buildings that are designed to exhibit ductile behavior during earthquakes. In this study, this adverse effect is demonstrated quantitatively through nonlinear pushover and nonlinear time-history analyses of a hypothetical RC frame building. To obtain more general conclusions, different corrosion intensities and distributions of reinforcing bars and different earthquake records are considered in the analyses. Furthermore, the results of an experimental study on the seismic performance of RC columns with corroded reinforcing bars, which constituted the reason for the analytical studies, are presented.

Recently, two earthquakes ($M_{\text{W}}=5.3$ on February 14, 2006, and $M_{\text{W}}=6.9$ on September 18, 2011) struck the mountainous region of Sikkim, one of the most seismically active regions in India. The 2006 event, though of lesser magnitude, clearly showed the high seismic vulnerability of different structures in Sikkim, especially in the state capital, Gangtok. Damage observed in buildings in and around Gangtok was disproportionately high during the 2006 event, considering the small size of the earthquake. It was expected and hoped that the 2006 event would act as a wake-up call to all stake holders in the society to improve the construction practices in the region. However, the bigger earthquake of 2011 not only affected the older structures but also severely damaged a large number of new structures. Comparison of observed damage with structures in Sikkim during these two earthquakes clearly demonstrates an alarming rise in seismic vulnerability of structures in Sikkim.

A large number of stairways experienced minor to extreme damage during Wenchuan Earthquake ($M_s=8.0$) that shook northwestern Sichuan on May 12, 2008. A postearthquake field reconnaissance on buildings was carried out in the epicentral region. Typical stairway configurations identified in the epicenter areas and the corresponding damage experienced are discussed in this paper. Various types of seismic damage to the stairway components or the primary structures occurred because of the interaction between the stairways and the primary structural systems. The primary structures were affected by the formation of short columns or short beams and high local shear stresses in the floor diaphragms and beam-column joints of the stairwells. Stairway components were vulnerable to seismic actions where the distresses included cracking or spalling of concrete, buckling of reinforcing bars in the middle of the flights or at the stair flight-landing junction, high local stresses in the landing slab of L-shaped stairways and in the middle of landing beams, and stress concentration at the corner of Z-shaped stringer. Brittle stair enclosures and finish materials were particularly hazardous due to their falling debris.

Foundation movements attributable to expansive clays and claystones continue to challenge the geotechnical and structural-engineering communities. This study summarizes information and data, collected over the past 25 years, associated with the investigation, monitoring, and repair of numerous structures affected by expansive soil movements in Colorado. The paper provides a brief history and description of the various foundation systems that have been used in Colorado in an effort to prevent or accommodate soil heave. From the sites included in the study, real data on the rates of movement versus time and the time to stabilization are presented. Also provided is a summary of various remedial approaches used to address foundation movements. Lastly, the subsequent performance of foundations that have stabilized without underpinning as well as those that have been proactively stabilized are described and discussed.

Adhered ceramic tiles are one of the most commonly used exterior cladding materials in Portugal. However, various durability problems are also noted by the researchers. A research study was therefore designed to identify in situ inspection techniques that can be used for detecting moisture-content increase and delamination problems of this type of cladding, and for this purpose 16 buildings in Lisbon were inspected by infrared (IR) thermography. In IR thermography, various factors affect data collection and interpretation and this may lead to false or questionable indications. Factors of this nature observed during the in situ passive thermographic inspection of these 16 buildings have been gathered and systematized to support the decision whether to use passive thermography in detecting moisture and delamination problems in an adhered ceramic cladding of a particular building, considering its characteristics. The factors observed were organized in two main groups associated with (1) the building/site inspected, and (2) IR thermography. Finally, an interaction matrix is proposed for the identification of the factors that can influence the execution of a thermographic inspection.

The condition of the physical environment within healthcare facilities has a large impact on the quality of care, recovery time, and patient satisfaction. To maintain and ensure adequate operation of the physical environment, facility management must maintain a state of continuous compliance and constant readiness. This requires the facility management personnel to have a full understanding of the regulatory standards and guidelines that address the performance of a healthcare facility. This paper discusses an analysis of the major healthcare standards and guidelines that the American Society of Healthcare Engineers suggests facility management groups need to be familiar with. A gap analysis is performed to identify gaps between the design and construction guidelines and their ability to support healthcare facility operation and performance standards. Finally, a case example is used to discuss how the standards and regulations can be incorporated into a healthcare facility information framework to support facility operations and performance compliance.

In Spain, the high levels of inexperienced workers and the long chains of subcontracting contribute to the poor quality of dwellings. Although the Ley reguladora de la subcontratación en el Sector de la Construcción (subcontracting law) has established quality measures, the number of customer complaints is still increasing. In this paper, a total of 2,351 posthandover defects derived from four Spanish builders and seven residential developments are classified according to their source and origin. The research reveals that the most common defects identified by customers at posthandover were derived from bad workmanship and were related to construction errors and omissions. Typical defects were found to include incorrect installation, appearance defects, and missing an item or task mainly related to finishing and considered to be minor. No defects were caused by poor design because they are mainly detected and resolved during construction or become apparent after some years of use. This study demonstrates the negative impact of redoing defective work during the final stages of construction and provides knowledge to define measures to improve the quality of the finished buildings, such as understanding customer expectations and preferences, training programs for workers, specialization of subcontractors, and tightening external controls prior to handover.

Deterioration trends derived using discrete condition data are commonly used in management of civil infrastructure assets. However, the high variability of condition data often makes the derivation of deterministic models difficult and unreliable. Therefore, reliability-based methods such as Markov chain have been used to establish trends using highly variable condition data. Although these methods have been explored in assets such as bridges and roads, the use of reliability-based methods in deterioration prediction of buildings is less common. The second-largest class of infrastructure assets owned by the local governments in Australia is community buildings. Because most existing community buildings are maturing, the local government agencies seek more reliable asset management strategies. Physical condition–based forecasting is a major component of such asset management approaches. This paper presents the development of a reliability-based methodology for the deterioration prediction of community buildings. The gamma process is considered to be an appropriate approach for predicting building element deterioration because of the associated temporal variability of degradation. The gamma deterioration process presented in this paper is a stochastic process with independent nonnegative increments having a gamma distribution with an identical scale parameter. Building inspection data from one of the local governments in Victoria are used in the model. Further, the paper discusses the analysis of the data and practical application.

Localized spalling/cratering of concrete structures subjected to close-in detonations may lead to global structural failure. This paper presents the details and results of a numerical study conducted on posttensioned concrete box girder bridges under close-in detonations. A bomb explosion within or near the bridge deck may cause catastrophic damage to the bridge components. Blast causes highly dynamic loads much larger than the conventional design loads applied relatively locally. In contrast to the bridge superstructure, significant research has been performed on the response and retrofit of buildings under blast loads. The published research on the response prediction and protection of bridges under near-field blast loads are limited. This study focuses on the evaluation and assessment of box girder bridges under blast loads. The objective of this research is to develop a reliable numerical model to predict the damage (spalling/cratering) size in a concrete deck under blast loading and the corresponding dynamic response of the damaged bridge system. The key parameters evaluated were the charge weight, charge location, and concrete deck properties. The results of this study make finite-element (FE) modeling an attractive alternative when blast testing is not feasible such as in the case of bridges. The numerical model was verified using close-in detonations on concrete slabs. Verification of the numerical model results using blast field testing on bridge systems is still necessary before this study can be expanded for additional parametric studies and comprehensive design recommendations. The damage sizes of the RC box girder bridges were predicted and assessed using a nonlinear dynamic FE code. Nonlinear regression analyses were conducted and an equation to predict the damage size depending on the scaled distance was introduced.

Structural health monitoring (SHM) is a relatively recent approach to managing and extending the useful life of bridge infrastructure elements. To be useful, SHM techniques must be robust, rapidly deployable, and yield information useful to those rating the structures. Fiber optic–based sensors have been used in this regard but on a relatively limited basis in North America. Fiber optic sensors have many advantages over more conventional structural monitoring sensors, and their utility has been well established. While verification of SHM-generated data with other instrumentation schemes is important, validation using simple analytic tools is critical because such tools are the basis for most bridge rating and management systems. In this paper, load testing of a decommissioned prestressed adjacent box girder is presented. The objective of the test was to demonstrate a proof of concept for a fiber optic–based instrumentation system for bridge monitoring. Fiber optic–generated measures of girder performance are compared with other experimental test data and a relatively simple but robust analytic model of the girder. The tested fiber optic system demonstrated excellent performance, and data recovered correlated well with a well-established analytical modeling technique, thereby demonstrating the immediate utility of the fiber optic system.

This study addresses lessons learned from maintenance experiences in hydraulic tunnels in Taiwan. The characteristics of structural safety inspection are first discussed, and common anomalies in the linings of the hydraulic tunnels are illustrated. The repair and rehabilitation issues are then reviewed based on practical examples. Experience of inspection and maintenance shows that, based on a life-cycle perspective, the planning and design of a hydraulic tunnel should take into consideration, in detail, the long-term stability issues and required maintenance tasks during the service life of the tunnel, reserve all necessary preparatory facilities, and provide the clearance needed for any required work. In the construction stage, incorporating preprocessing measures for solving potential problems likely to occur during tunnel operation is essential. Initial inspection should be performed and maintenance databases should be established immediately upon completion of construction.

The paper presents the results and conclusions from field tests under service loads conducted on a corrugated steel plate (CSP) road culvert. Strains and displacements were measured in selected cross sections of the culvert during the passage of vehicles. The field tests lasted for 24 h. On the basis of the measured displacements, using the fast Fourier transform method, the dominant frequencies of the culvert were determined. The logarithmic damping decrements and the damping ratios were also calculated. The maximum displacement and strain of the culvert did not exceed $0.74\times {10}^{-3}\hspace{0.17em}\mathrm{m}$ and $-43\times {10}^{-6}$, respectively, and the maximum values were obtained in the crown of the structure. The culvert axial thrusts obtained from the field tests were compared with those calculated from the analytical methods [Sundquist-Pettersson, Canadian highway bridge code (CHBDC), and AASHTO LRFD], and in the case of bending moments, those calculated by the Sundquist-Pettersson method exclusively. The results clearly highlight the conservative approach of the AASHTO LRFD standard in calculating axial thrust. The Sundquist-Pettersson and CHBDC methods provided values (axial thrusts and bending moments) that are closest to the ones obtained from the field tests. The conclusions drawn from the tests are helpful in assessing the dynamic behavior of CSP road culverts. In the case of small-to-medium span culverts and bridges of this type, the conclusions from the field tests can be generalized for all types of such structural solutions.

The purpose of this paper is to describe the development of and typical results from a new field-monitoring system to evaluate changes in matric suction and temperature profiles in subgrade soil layers beneath constructed pavement systems over an extended period of time. This monitoring system involves the placement of sensors capable of inferring the volumetric water content and temperature of soils into a borehole in the shoulder of an existing pavement. High-permeability silica flour is used to backfill the borehole around the sensors so that changes in matric suction with depth in the subgrade can be inferred through the soil-water retention curve of the silica flour. The monitoring results from a pavement site in Arkansas with low-permeability clay subgrade are compared with predictions from the Enhanced Integrated Climatic Model (EICM). The measured and predicted temperature distributions match well, but the EICM did not capture the fluctuations in matric suction inferred from the monitoring system. This can be attributed not only to the fact that the monitoring system captured the two-dimensional water flow near the pavement shoulder but also to the possibility that the EICM may not have adequately represented the water-flow process through the asphalt and base-course layers. Profiles of matric suction and temperature obtained using the monitoring system provide real-time, site-specific feedback on interactions between the atmosphere and pavement systems. Comparison of results from multiple pavement sites with clay subgrades across Arkansas demonstrates the variability in matric suction and temperature changes in different climatic settings.

This paper describes the surveying, engineering, and construction operations performed in the construction of the Gunnison Tunnel for the Gunnison River Diversion Project. The Gunnison Tunnel, which diverts water from the Gunnison River to the Uncompahgre Valley, was one of the first major engineering projects undertaken by the federal government under the authority of the U.S. Reclamation Service. It has been recognized as a national historic civil engineering landmark for the engineering feats involved in its construction, including the performance of site investigations and survey operations through extremely harsh terrain and its construction crews’ perseverance through several dramatic accidents. It is observed that a potential cause of these multiple accidents was an insufficient knowledge of the geological subsurface properties, leading to significant differences between expected and encountered subsurface conditions. This was particularly problematic with respect to the existence of cohesionless soils and water and gas seams, resulting in numerous fatalities and injuries among hard rock miners who were inexperienced with tunneling through cohesionless soils.

This paper summarizes the evaluation of a thin-bonded epoxy overlay placed on an asphalt-wearing surface in an effort to increase skid resistance, decrease wear of the bridge deck, reduce the development of bonded snow and ice during winter conditions, and provide a safe drivable surface. The uniqueness of this study is the installation of a polymer-based overlay with anti-icing/antiskid properties on an asphalt-wearing surface. This thin-bonded epoxy overlay was examined based on mean texture depth, surface friction, bond strength, ability to stop chloride intrusion, anti-icing properties, traffic safety, and cost. Mean texture depth and friction testing produced a durable wearing surface with good traction. Bond strength test results demonstrated that the asphalt layer will fail prior to the epoxy overlay. Chloride content of the concrete bridge deck decreased with the use of the thin-bonded overlay. The anti-icing property of the overlay is effective when precharged with deicing chemicals but seems ineffective with excess moisture present on the overlay surface. A reduction in crashes has been observed after one winter season; however, further study is required.