Journal of Performance of Constructed Facilities

Skewed bridges are susceptible to seismic damage due to their complicated dynamic responses. A range of potential retrofit strategies have been implemented to mitigate damages in seismically deficient bridges. However, because the seismic responses of skewed bridges often differ from straight bridges, and the efficiency of each retrofit measure may vary from one class to another, a comprehensive study with a wide range of retrofit options among skewed bridges is needed. This paper assesses the impacts of 10 different retrofit strategies on the fragility of skewed single-frame concrete box girder bridges with seat-type abutments in two common subclasses termed single- and two-column bent. Fragility curves corresponding to four damage states at both the component and system levels are developed for various skew angles. The results show that, although no single retrofit measure can solely contribute to decreasing all component and system vulnerabilities in highly skewed bridges, combinations of retrofit measures can be used to enhance the desirable level of skewed bridge performance. The level of effectiveness of a retrofit option is highly dependent on bridge class and skew angle.

Over the past couple of decades, quality has been an area of increased focus. Multiple models and approaches have been proposed to measure the quality in the construction industry. This paper focuses on determining the quality of one of the types of roofing systems used in the construction industry, i.e., sprayed polyurethane foam roofs (SPF roofs). Thirty-seven urethane-coated SPF roofs that were installed in 2005/2006 were visually inspected to measure the percentage of blisters and repairs three times over a period of four years, six years, and seven years. A repairing criteria was established after a six-year mark based on the data that were reported to contractors as vulnerable roofs. Furthermore, the relation between four possible contributing time-of-installation factors—contractor, demographics, season, and difficulty (number of penetrations and size of the roof in square feet) that could affect the quality of the roof was determined. Demographics and difficulty did not affect the quality of the roofs, whereas the contractor and the season when the roof was installed did affect the quality of the roofs.

In recent years, the so called jointless or integral bridge design has seen a significant rise in popularity in Europe. Whereas in the last decades, designers preferred clearly defined statical systems and only adopted jointless design principles for small structures, the new generation of engineers pushes for integral design wherever possible. This development is to some degree motivated by a paradigm shift towards life-cycle cost-orientated design. Integral bridge structures lack joints and bearings, which typically are the least durable elements and thus remove the need for costly inspections and replacements. However, the obvious advantage of reduced direct and indirect maintenance costs entails novel and complex design solutions, especially for the transition area between structure and soil body. Furthermore, their statically indeterminate nature leads to increased importance of the soil–structure interaction. Both aspects are associated with significant uncertainty. This contribution focuses on the probabilistic performance assessment of an inclined approach slab solution for integral bridge structures of up to 150 m of total length. Findings are presented by the example of a recently constructed and ever since monitored 67-m-long prototype structure. Monitoring data recorded by a multisensor monitoring system during the first 30 months after construction serves as inputs for a probabilistic, extreme value-based assessment of critical design assumptions. In particular, (1) the modeling of boundary conditions, (2) the activated degree of earth pressure against the abutment wall, and (3) the strain distribution in the fiber-reinforced soil above the inclined approach slab are investigated.

The purpose of this study is to calculate the maintenance interval time (MIT) of steel structure of a large gantry crane in shipyard and provide basis for a maintenance plan. By analyzing a mechanical model of the lifting process, stress spectrum and fatigue damage are calculated. Based on the fatigue reliability theory, rational MIT and maintenance strategy are suggested. Compared with the existing empirical regulation, the solution of this study is safer, cheaper, and more efficient.

This study focuses on determining the effect of different types of binder and aggregate on chip seal performance in both laboratory and in situ settings. Eight different chip seal test sections were constructed on existing asphalt concrete as the pavement preservation technique of choice. Two different binders, CRS-2L modified emulsion and B100/150 penetration hot asphalt cement, were used in the test sections. Also, two types of aggregate, limestone, and basalt, were used. The sand-patch test as well as visual evaluations was conducted on the test sections regularly. In addition to physical and chemical characteristics, the adhesion resistance of the utilized materials was determined in the laboratory and compared with the test section results. The loss of aggregate (also called raveling or shelling), bleeding deteriorations on each test section were evaluated over time in respect to binder and aggregate type. The results indicate that after chip seal construction, the macrotexture of the existing asphalt concrete increased significantly. It was also determined that CRS-2L chip seal showed better performance than B100/150 penetration hot asphalt cement. With regard to the type of aggregate used for the chip seal, limestone showed better raveling performance when compared with basalt. In addition, in the test sections, the right and left lanes demonstrated different levels of severity distress because of varying traffic distributions. It was also seen that macrotexture is one of the best parameters to determine chip seal performance and to follow its progress over time.

Shotcrete liners are being utilized more frequently in transportation infrastructure as retaining structures and tunnel covers. Despite their economic advantages to concrete, the initial quality of construction and long-term durability of shotcrete liners are of concern among highway agencies. The quantitative construction quality management is needed to ensure adequacy and uniformity of strength and thickness. Also, periodic inspection of shotcrete liners is necessary to assess possible material deterioration and to detect the onset of defects. The impact echo and ultrasonic surface wave methods are two nondestructive sonic methods that have been proven effective for those purposes in concrete structures. Unlike concrete slabs, shotcrete slabs exhibit spatial heterogeneity. In addition to heterogeneity, surface roughness of shotcrete adds some complications into data interpretation in terms of thickness measurement. The practical effectiveness of applying these methods to shotcrete liners using a commercially-available nondestructive testing device was evaluated in three actual tunnels. This paper focuses on validating the effectiveness of these methods through a well-controlled testing on a number of shotcrete specimens constructed with and without known defects. Results from this study demonstrate that the stiffness of shotcrete layer and the presence of delamination and voids within the shotcrete liners can be detected well by using these seismic methods in combination.

The wide use of tensioned membrane structures (TMS) is prominent in many designs because of its aesthetic, ergonomic, and economical nature. Recently, TMS has been applied in the tropics with success, yet defects specific to this region have received little attention. Through a questionnaire survey of 890 users and technicians of TMS in three different areas in Malaysia, this study identified the most frequently occurring TMS defects in the tropics, such as “deterioration of roof coatings,” “corrosion or fatigue in fixings,” “fungal decay, mold growth, and dirt in membrane,” “corrosion in anchor cables,” and “degradation of fabrics.” These defects are quite different from those in other climatic zones. The top five causes of TMS defects in the tropics are weather, aging, design, construction/installation, and material selection. However, only “corrosion or fatigue in fixings” is a significant predictor for “deterioration of roof coatings.” While this is not a causal effect, a practical implication is that TMS maintenance workers do not have to climb up to the roof to check the deterioration in coating but only need to predict the deterioration through the corrosion levels of the fixings. Further, seven countermeasures for TMS defects in the tropics are recommended. This study is the first comprehensive study examining tensioned membrane structure defects in the tropics.

This paper presents a study of selection of procurement method in building maintenance management for public universities in Malaysia through the use of multiple criteria decision making (MCDM), particularly the analytic hierarchy process (AHP). There are many different types of procurement methods that have been developed to overcome the weaknesses of the existing procurement method and to meet the range of service requirement. The decision makers are faced with challenges when it comes to selecting the most appropriate procurement method for a specific building as different types of procurement methods suit different types of projects. This research seeks to investigate the current practices of the available procurement methods for building maintenance work in public universities and identify the procurement selection criteria to develop an effective decision-making framework. A questionnaire survey was conducted among 20 public universities in Malaysia with 85% response rate to identify and validate two important components for the development of a decision-making framework: the possible assessment criteria and the alternatives available for selection. The finding of this research proves that the selection of procurement methods by university organizations is neither strategic nor systematic as there is no guidance available for the decision maker to rely on in order to select the most appropriate procurement strategy. It is vital to develop a systematic approach that can assist maintenance personnel in making a decision on selecting procurement methods for a particular building.

A half-scale physical model of a thin-tile masonry dome designed by Rafael Guastavino, Jr. that is located in the Nebraska State Capitol Building is constructed and tested both nondestructively and destructively to determine the load paths of the structure as well as the reactions at the support. A corner support of the model dome is incrementally displaced horizontally and the resulting crack locations are identified. Additionally, a linear finite element model of the dome, validated with experimental modal analysis, is modified to perform nonlinear analysis where loads are placed on the dome and the resulting stresses and reactions determined. The results from the nonlinear finite element model are then compared to the destructive testing carried out on the constructed physical model. From the results of both the nondestructive and destructive testing, it is determined that the thin-tile masonry dome in question acts as a pendentive dome, which exerts horizontal thrust as well as vertically transmitting a portion of the load to the supporting columns. Additionally, the results show that the quarter points of the arches and dome webbing pendentives experience the highest stress levels under both vertical loading at the crown and horizontal support displacement, and as such are the most susceptible to initiate the system failure.

In general terms, construction rehabilitation is not sufficiently studied worldwide in civil engineering schools. This article proposes an international guideline course on construction rehabilitation for civil engineering students at the bachelor degree level. As we live in an increasingly globalized world, the course aims to prepare students in the same basic concepts so the course content and its focus can be common for all civil engineering programs worldwide. Nevertheless, the course should be considered as a general guideline. At each university, special attention should be paid to the topics that are most common due to the varying construction practices, preservation laws and regulations, and legal jurisdiction governing the scope of practice in construction rehabilitation that exist in the region/country in which the university is located. Moreover, the guideline course should be focused on existing building types, both significant historic ones and those that make up the day-to-day rehabilitation market. To achieve this, the initial step of the methodology was the study and integration of the results obtained in a survey sent to lecturers at 89 universities in 30 countries around the world. Then, a preliminary grouping was done of topics that could be included in the course, preassigning a teaching time to each topic. Later, various renowned experts in the matter audited the tentative guideline course. Finally, based on their opinions and comments, the definitive guideline course was rewritten. Through this course, civil engineering students will improve their ability to recognize, analyze, diagnose, and solve problems that commonly appear in existing buildings, and they will increase their knowledge about maintaining and conserving them.

Structures underneath pavements commonly reduce the bearing capacity of the ground because of poor compaction and long-term settlement at sites around these structures. When a load is applied at these sites, the stress on the concrete slab increases and may exceed the design strength, inducing distress and shortening the lifespan of the pavement. In this study, we investigated the transverse cracking of concrete pavement slabs above box culverts in a test road of the Korea Expressway Corporation. Transverse cracking in the slabs was surveyed in both the north- and southbound lanes with different cover depths over the box culverts. To examine the transverse cracking, the jointed concrete pavement of the test road containing the culvert was modeled and analyzed by the finite-element method. Wheel loading was applied after taking into account the self-weight of the pavement and the temperature gradient within the concrete slab. The positions and magnitudes of the maximum tensile stress and the corresponding positions of wheel loading were investigated for each loading combination. In this manner, we identified the optimal joint positions for which the maximum tensile stress in the pavement slab is minimized. We also analyzed the behavior of the pavement in relation to the cover depth and reinforced concrete transition slab length. Accordingly, we proposed an appropriate length for the reinforced concrete transition slab to ensure minimized tensile stress in the pavement slab.

Two sections from a decommissioned bridge were salvaged and tested to quantify flexure and punching shear capacities. The salvaged bridge sections each consisted of two built-up, steel-plate girders, compositely attached to precast concrete, deck panels. The deck panels were part of an accelerated bridge construction (ABC) project and were connected to one-another using female-to-female, flexurally discontinuous, transverse joints. Experimental results were compared with theoretical-based results produced from AASHTO LRFD specifications design procedures. Measured flexural capacities exceed the AASHTO computational design capacity by 30%. The precast panels and transverse joints were also tested for punching shear capacity and found to range from 144 to 87% in comparison to the AASHTO LRFD values, depending on the proximity to the transverse joint. Nonlinear, finite-element models validated the experimental results. The analytical models had excellent agreement with experimental deflection, reaction forces, regions of yielding, and the ultimate flexural capacity.

Prestressed concrete exhibits resistance to damage induced by fire and associated elevated temperatures, often permitting reuse of structural elements following exposure to accidental fire. However, prudent determination of suitability for reuse or rehabilitation of fire-damaged prestressed concrete requires a post-fire structural evaluation, which can be greatly aided by application of nondestructive testing for quantitative assessment of residual material properties, structural strength, and serviceability. In this study, a suite of nondestructive inspection and evaluation methods including visual documentation, camber surveying, penetration resistance testing, and impact-echo are applied to fire-damaged and unaffected double-tee joists of a precast, prestressed roof system. Qualitative and quantitative measures of fire damage obtained through the nondestructive tests are presented and strong correlations, in particular between longitudinal wave speed estimates obtained in impact-echo testing and depth of probe penetration, are exhibited in the test results. Furthermore, the test results are compared with empirical models of residual compressive strength and residual elastic modulus of concrete following exposure to high temperatures. These results support recent laboratory studies suggesting that nondestructive measurements of longitudinal wave speed or pulse velocity through fire-damaged concrete may be linearly related to relative reductions in compressive strength. Results from a survey of the camber in the fire damaged joists is also presented with conceivable interpretation of the observed profiles to highlight the shortcomings of this often recommended practice and emphasize the need for more definitive nondestructive test methods.

This paper demonstrates the analysis of the deterioration trends of the various types of bridge structural design and/or construction in the entire U.S. National Bridge Inventory, to derive and compare operational structural performances. The approach considers the trends of the proportional accumulation of deterioration by bridge types, based on the concept of structural deficiency and the objective of life-cycle expectancy at the serviceability limit states. The analysis determines the rate and pattern of the deterioration trends. The multiple-criteria diagnostic approach integrates the rate and pattern performances with the condition, durability, and longevity performances to determine the overall equivalent structural performances using prioritized weights. This study produces the most comprehensive national network-level comparative basis of the operational structural performances of bridge types under the actual circumstances. The deterioration trend performances of most bridge types are relatively lower. Also, the overall equivalent structural performances of almost all bridge types are lower. The analysis also helps identify critical accumulation of deterioration for bridge types, suggesting focused improvement efforts necessary for existing and future bridges. The most common stringer/multibeam or girder bridges have relatively higher and faster accumulation of deterioration, generating a below average trend and equivalent structural performances. The results help predict future performances and improve effectiveness of bridge types for sustainable service life.

Prognostic evaluation involves constructing a prediction model based on available measurements to forecast the health state of an engineering system. One particular prognostic technique, support vector regression, has had successful applications because of its ability to compromise between fitting accuracy and model complexity in training prediction models. In civil engineering applications, compromise between fitting accuracy and model complexity depends primarily on the measured response of the system to loads other than those that are of interest for prognostic evaluation, referred to as extraneous noise in this paper. To achieve accurate prognostic evaluation in the presence of such extraneous noise, this paper presents an approach for optimally weighing fitting accuracy and complexity of a support vector regression model in an iterative manner as new measurements become available. The proposed approach is demonstrated in prognostic evaluation of the structural condition of a historic masonry coastal fortification, Fort Sumter located in Charleston, South Carolina, considering differential settlement of supports. Within this case study, the adaptive optimal weighting approach had increased forecasting accuracy over the nonweighted option.

The excavation of a large-sized foundation pit for one skyscraper in Shanghai required installation of a 100-m diameter unpropped circular diaphragm wall at the pit center first, followed by installation of a multipropped rectangular diaphragm wall at the periphery. Due to the limited paper length, this study just focuses on the structural behaviors of the inner circular wall and those of the outer rectangular wall will be presented in a companion paper. The circular diaphragm wall exhibited apparent spatial arching effects during excavation and only slight differences were observed in its maximum lateral movements along the circumference. Like braced struts, waler beams mainly carried the load due to soil removal in the proximity. In contrast, the circular diaphragm wall carried the hoop stresses due to soil removal throughout the excavation. The vertical bending stresses in diaphragm wall panels were symmetric about their neutral axes. Although the adopted remedial measure effectively mitigated their potential adverse effects on wall deformations, structural deficiencies (e.g., diaphragm wall panels encountered the existing long driven piles at several locations) resulted in some detrimental effects (e.g., tension stress development in concrete and uneven stress distributions in retaining structures). Throughout the construction, the stress development patterns in concrete corresponded well with those in reinforcing rebars, which indicated that the retaining structures were not overstressed. The comparisons between the design analysis results and the field measurements show that the adopted beam-on-elastic-foundation method can make relatively reasonable estimation on excavation-induced deflections of the unpropped circular retaining wall.

Via analyzing the field instrumentation data, this study examines the structural behaviors of the multipropped diaphragm wall for excavation of the outer rectangular pit. The circumferential stresses in waler beams as well as boundary beams were closely related to the corresponding wall deflections. Braced struts might lead to stress-concentration in the retaining structures. Because of the uneven vertical movements of floor slabs, boundary beams suffered bending stresses. The stresses in interior columns were governed by the weights of cast floor slabs and rebounds of basal soils. The significant upward movements of interior columns and heavy floor slabs indicate that the released stresses due to soil removal outweighed the heavy weights of the retaining structures. The excavation-induced lateral loads against the retaining wall were mainly carried by the rigid floor slabs and concrete beams, which were up to 10 times or more those carried by the temporary propped struts. The comparison between the field data and the design analysis results shows that the theoretical beam-on-elastic-foundation design models can make a relative reasonable estimation on the wall deflections for the unpropped circular diaphragm wall, but highly underestimated the wall deflections of the multipropped rectangular diaphragm wall. The potential adverse effects resulting from structural deficiencies (e.g., openings on floor slabs for soil discharge) and pit-size effects on weakening the capabilities of cast floor slabs or braced struts to constrain wall deflection should be taken into account in design analysis of top-down excavations.

This research is a complementary study to a recent experimental study on a newly developed seismic isolator called ball rubber bearing (BRB). BRB-type isolators can be easily manufactured similar to the standard elastomeric bridge bearings and can provide significant energy dissipation during an earthquake through friction provided by steel balls inside the cylindrical core. Structural response of BRBs at low temperatures has not been examined in previous research. In this research, behavior of BRBs exposed to different simulated weather conditions is tested under combined axial and cyclic lateral load. Comparison of room temperature and low-temperature test results indicates that the BRB can have slightly increased damping characteristics and horizontal stiffness in cold-weather conditions. This shift in performance has been included in the proposed design recommendations.

An output specification is an integral part of the contract documentation for procuring and monitoring public private partnership (PPP) or private finance initiative (PFI) projects throughout their life cycles. Unlike prescriptive specifications used in the traditional project delivery, the output specifications stipulate what is required from the project rather than how they should be delivered by the private sector. Performance standards or output parameters are used for bid evaluation and operational monitoring. Failure to achieve them would lead to ongoing payment deduction and rectifications that need to be undertaken within a specified time frame. The long concession periods of PPP/PFI projects mean that changes are inevitable, and these, if foreseeable, should be managed using the output specification as a tool. This unconventional approach of specifying requires special skills and care. This paper presents the results of a questionnaire survey conducted in Australia and the U.K. with PPP/PFI practitioners. The findings highlight the common pitfalls and change management issues encountered by the two jurisdictions, which use PPP or PFI extensively in delivering public assets and services. While common pitfalls include conflicts between input and output specifications, and performance standards being compromised with affordability, small changes are often made by the public sector authorities. Changes are dealt with by anticipatory provisions in output specifications, or negotiations as and when they arise. Procedural hiccups may slow down the process of introducing necessary changes, or give rise to disputes.

This paper presents a method to facilitate the assessment of the performance and analyze the degradation of building envelopes, focusing on painted finishes. The proposed solution consists of systematizing the inspections, diagnosis, and rehabilitation methods through the compilation and structuring of the data contained in current regulations and scientific publications which are later validated and adjusted by the statistical analysis of data gathered in an inspection’s campaign. The field campaign included a sample of 105 façades with painted renders in the city of Lisbon, Portugal. The scope of the sample was limited to painted rendered façades (cementitious or mixed-binder mortar), therefore excluding other substrates. As a result, terminology, techniques, and procedures are combined into a single innovative system that allows unequivocal decision-making regarding inspections and intervention on paint coatings, thereby minimizing reliance on the experience of the inspector. The system is composed of several tools including classification lists, correlation matrices, and individual files compiling information on pathologies, testing, and repair techniques. The method for application of these tools is also described in this paper.

This study aims to present an integrated method in a probabilistic manner for seismic performance assessment of Turkish residential buildings, which can be used as a tool to estimate earthquake losses due to structural damage. In particular, the objective is to determine the performances of different types of residential buildings for predicting the potential seismic loss in terms of casualties (death toll) for a highly populated city in northwestern Turkey. The main phases of this study are seismic hazard, building performance in terms of fragility functions, and loss in terms of damage states of buildings and total number of casualties. To quantify the regional hazard, a probabilistic seismic hazard assessment approach is adopted. For different types of building structures, probabilities of satisfying predefined performance levels for a given hazard level are determined using appropriate fragility curve sets produced by using local characteristics. The results are expressed as expected losses in 50 years in terms of number of casualties obtained as a function of the estimated performance of building types under concern.

This paper investigated the influence of atypical agricultural vehicle parameters on girder distribution factors (GDFs) for two simply supported steel-concrete composite bridges located on secondary roads in the United States. As part of the parametric investigation, field measurements were performed on the bridges under the passage of full-scale agricultural vehicles along each bridge centerline. Strain data obtained from field tests were used to determine field GDFs. Both field data and GDFs were used to calibrate a finite element model of the bridge. Data from over in-use one hundred agricultural vehicles were collected, and then each vehicle was applied to the model to compute analytical GDFs. These vehicles were analytically and statistically investigated to determine the sensitivity of GDFs to vehicle parameters, including maximum vehicle axle load, gage width, and spacing distributions. Based upon field strain investigation for the two bridges, the responses of the central girders were greater than those of the exterior girders, resulting in greater field GDFs for central girders than those of the exterior girders. Results also indicated from the sensitivity study that each girder had different levels of correlation between GDFs and single vehicle parameters.

The modulus of subgrade reaction is not a unique fundamental soil property that can be readily measured, and its magnitude is an outcome from a soil-structure interaction. But it is required by structural engineers for the structural design of a tunnel. The adoption of an appropriate magnitude for the modulus of subgrade reaction is crucial to ensure that the structural design of the tunnel will be adequate. Some engineers inappropriately rely on the plate load test to determine the magnitude of the modulus of subgrade reaction of the underlying stratum for the structural design of the tunnel. This paper will discuss an appropriate approach to estimate the magnitude of the modulus of subgrade reaction of weak sandstones and siltstones underlying a 2-km tunnel. This tunnel was completed and extensive cracks were noted prior to the opening of the tunnel. This prompted an investigation that included a design review that identified the important issue of an appropriate method for determining the magnitude of the modulus of subgrade reaction for the tunnel design. Typical values for the moduli and Poisson’s ratios of weak sandstones and siltstones required for the soil-structure interaction analysis will be discussed based on a review of the existing literature and the results of plate load tests, pressuremeter tests, and unconfined compression strength tests of the soil investigation report for the tunnel project.

After the Northridge and Kobe earthquakes important experimental programs on beam-to-column connections were developed because of brittle fractures at welded beam-to-column connections. A number of studies are being carried out on a variety of materials and systems that dissipate the seismic loading effects in order to improve the seismic performance of steel frames. In the research reported in this paper, a slit steel damper system was developed to prevent the damage formation of standard columns and beams by dissipating lateral loads at the beam-to-column connections of steel frames. Therefore, the columns and beams of steel frames will not be damaged after a heavy earthquake, and the structures might be put into the service again simply by replacing the dampers at the connection sites. The seismic performance of the studied connection was verified through cyclic tests of two full-scale steel frames that had slit dampers and of one specimen that had a conventional extended end-plate connection. Test results indicated that the proposed connection showed a good hysteretic behavior, a good energy dissipation capacity, and good rigidity. However, plastic deformation is limited to the slit dampers, while the inelastic behavior of the beams and columns is prevented.