Journal of Performance of Constructed Facilities

Because failure of roof systems in past high wind events has demonstrated the consequences of not maintaining a continuous load path from the roof to the foundation, many studies have been conducted to better understand this load path, including how loads are distributed in the system. The current study looks to add to the current knowledge of the vertical load path by focusing on uplift loads and by considering the sensitivity of different modeling parameters. This is done by developing and assessing load influence coefficient contours for various roof-to-wall (RTW) connections. An analytical model of a light-framed wood structure using finite-element software is developed. The model has a gable roof system comprised of fink trusses and is modeled in a highly detailed fashion including the explicit modeling of each connector/nail in the system. The influence coefficient plots indicate that the distribution of loads is indeed sensitive to the overall stiffness of RTW connections but is not overly sensitive to their relative stiffnesses. This was investigated by looking at cases where all connections have the same stiffness and cases where they can have different stiffnesses. However, the relative stiffness begins to have a larger impact as they begin to soften because of yielding. Furthermore, the stiffness of the sheathing connectors did not appear to have much of an impact on the distribution of load, but the sheathing stiffness itself did have a notable impact.

This case study presents the horizontal translocation of the Hongxing Mansion, a high-rise building in China, which was moved transversally for 26 m because of modifications in urban planning. The 13-story RC frame-wall structure was built in 2002 with a total height of 63.2 m and a total weight of 109,881 kN, making the project unique as compared with other similar cases. The executive process of this project is introduced, including the initial planning, design, and construction procedures. A load underpinning system was proposed that can transfer the vertical loads uniformly to the rails and distribute the propelling loads from the loaded end to the other end of the building. Anchor-jacked piles were used at the original foundation from the limited indoor clear height so that rails in the original basement can be well supported without the need of large piling machines. A special moving system was proposed and successfully applied, which combined the advantages of pull and push, so that the efficiency and stability of moving were guaranteed. The removable reaction frames were used to alleviate the energy accumulation in tendons and the sudden energy release when the building started to move. Finally, the columns and walls were connected with the new foundation without diminishing their seismic capacities. The design and construction methods in this project provide references to buildings in need of translocation.

This study characterizes the mechanical performance of unreinforced and reinforced liquid-applied roof waterproofing systems (LARWS) based on several polymer types and links it to the pedestrian accessibility of roofs. The influence of the thickness and reinforcement on the system’s performance was assessed on free-film samples of cementitious, acrylic, liquid silicone, liquid rubber, and polyurethane-based systems. Tensile properties and resistance to dynamic and static indentation were determined. Further verification of fitness for intended use was assessed with watertightness and flexibility at low-temperature tests. The type of product was the most influential parameter on the mechanical performance of LARWS. The cementitious and the polyurethane-based systems had a much higher resistance to indentation than all the others, which were, at best, only fit for nonaccessible roofs. The use of internal reinforcement can improve the resistance to dynamic or static indentation. Using an extra coat of the product yields a higher resistance only to dynamic indentation. Deformability or stiffness could not be directly linked to a system’s resistance to indentation. A flexibility test at a low temperature ($\text{−}5°\mathrm{C}$) found that the mechanical performance of LARWS was not severely affected by those conditions.

The 50-year design reference period is coming to an end for many dam projects in China. In the last decade, it has become clear that remaining service life analysis of existing dams must be used to optimally manage the growing number of aging and deteriorating structures. The uncertainties associated with deteriorating dams require the use of probabilistic methods to properly assess their lifetime performance. A dam system involves multiple failure modes; however, conventional assessment and prediction models often neglect the correlations among failure modes. As a result, the remaining service life predicted by these methods is relatively rough. First, in this paper, conventional lifetime distribution functions are introduced. The influences of the correlations among failure modes on series, parallel, or series-parallel structure are discussed, respectively, and the approach for calculating correlation coefficients is proposed. Second, on the basis of the analysis of dam failure causes, failure modes of concrete gravity dams are defined, and the concrete gravity dam is reviewed as a series system with parallel subsystems. Third, the limit state functions for failure modes are given, and quantified progressive deterioration functions for various random variables to describe the aging process of gravity dams are obtained. Based on the correlation analysis and time-varying theory, a prediction model of remaining service life for gravity dam systems is finally proposed. An existing concrete gravity dam is investigated. Failure modes and deterioration mechanisms are studied. The results can be used to better predict the remaining service life of deteriorating dams.

A structural health monitoring (SHM) network was installed during the construction of a 56-story frame-wall concrete building with a height of 196 m. The SHM network recorded the vibrations produced by ambient, construction, and earthquake excitations. The vibrations were used to identify the natural periods, mode shapes, and damping ratios of the structure every 10 min for 6 consecutive months and at five specific stages of the construction process over a two-year period. The identified modal parameters were used to validate the construction process and the computer design model by comparing different adaptive computer models that correspond to the progress in construction. Maximum differences of 14% between measured and analytical model natural period were obtained, and correlation to modal shapes were close to 95%, which indicates a good approximation of the predictive design computer model. The experimental techniques also allowed for the direct measurement of the energy dissipation properties of the building. For the low amplitude vibrations, the modal damping ratio ranges from 0.7 to 1.6% for the largest natural periods. The occurrence of the 2010 Central-South Chile earthquake (magnitude $M_{\text{w}}=8.8$) also allowed for the comparison of the dynamic properties before and after an extreme loading event. A visual inspection of the building indicates an acceptable correlation between the minor damage observed and changes in the modal parameter values. The continuous monitoring of the dynamic properties of this permanently changing building proves to be an excellent tool for the verification of design models and quality assurance in construction control.

The overall aim of this paper is to identify critical success factors that would help Private Finance Initiative/facility management (PFI/FM) contractors to avoid performance failure payment deductions in Public Private Partnership/PFI (PPP/PFI) projects (constructed facilities). Using focus groups discussions, 36 possible factors that could influence performance failure payment deductions were identified and put together in a questionnaire survey. Analysis included reliability analysis that enabled identification of 29 reliable factors from the initial 36 factors. Using linear multiple regression, the best seven predictors that could help PFI/FM contractors to avoid performance payment failure deduction were identified from the 29 reliable factors. With the aid of another set of data and Spearman's rank correlation analysis, the seven predictors referred to as critical success factors were validated to confirm their dependability and wider applicability. The seven critical success factors include: (1) good working relationship with client, end-users, subcontractors, and suppliers; (2) minimal use of subjective measures as key performance indicators (KPIs); (3) a functioning help desk in place to receive service requests and complaints;, (4) explicit and realistic performance standards, criteria, and weighting systems; (5) quality of service delivery that meets requirements of output specification; (6) use of the Just-in-Time approach compared with a prescheduled maintenance regime; and (7) PFI/FM contractor active participation in the design process. The research findings would help both PFI/FM contractors and private project consortiums to maximize their profits/returns on investment by improving their performance and avoiding payment deductions in PFI projects. Public sector clients and occupants/users of their facilities would also achieve full value for money by enjoying facilities that adequately meet their needs and requirements.

A 3-story building with a mat foundation consisting of a slab on a grid of grade beams performed poorly on clay soil. Cracking of the slab became progressively worse as a result of the incorrect design and fluctuations in the groundwater pressure under the foundation. The cyclic presence and absence of water rusted the steel reinforcement, and the sulfates in the clay soil caused formation of ettringite in the concrete. Plastic hinges formed in the slab and settlements occurred, causing damage to the beams. The situation is still in progress and may lead to the collapse of the structure under normal service conditions. The geotechnical and structural investigations performed to survey and assess the aforementioned problems are described in this paper. The causes and the consequences of the detected anomalies are analyzed, and a prediction of potential future structural problems is provided. A strengthening procedure is proposed, and an estimate of the cost to realize it is provided. Recommendations are offered to help avoid the problem in new constructions.

This paper demonstrates trends in bridge structural deficiency and evaluates the operational structural performance of various types of bridge structural design and/or construction. The study analyzes the database of the National Bridge Inventory and derives data based on actual bridge deck areas, rather than discrete bridge counts. Based on the concept of structural deficiency and the objective of life-cycle expectancy for uninterrupted service life, the multiple-criteria diagnostic analysis determines condition, durability, longevity, and equivalent performance. For some bridge types, the results reflect limited remaining service life before structural deficiency is reached. Average service life is only 56% of life-cycle expectancy. The relatively higher condition performance contrasts with the significantly poor performance of durability and the relatively lower longevity. The equivalent structural performance of some bridge types is low. Overall, the study provides an indication of the current average potential, which serves as a basis for predicting future performance under similar operational conditions. The systems approach supports more objective design, maintenance, and decision-making practices, leading to more effective operation and management and more sustainable infrastructure solutions.

Timber bridges require high accumulated maintenance costs, which can be many times greater than their initial cost. Infrastructure managers need deterioration models to assist with making appropriate decisions concerning repair strategies and program maintenance schedules by accurately predicting the future condition of timber bridge elements. Markov chain–based models have been used extensively in modeling the deterioration of infrastructure facilities. These models can predict the condition of bridge elements as a probabilistic estimate. This paper presents the prediction of future condition of timber bridge elements using a stochastic Markov chain model. Condition data obtained from the Roads Corporation of Victoria, Australia, were used to develop transition probabilities. The percentage prediction method, regression-based optimization method, and nonlinear optimization technique were applied to predict transition matrices and transient probabilities from the condition data. The most suitable deterioration model for timber bridge elements was selected by evaluating the model performances using the goodness-of-fit and reliability tests. It was concluded that the Markov chain developed for deterioration prediction of timber bridges using the nonlinear optimization technique was mathematically acceptable and predicts the deterioration progression with reasonable accuracy.

A research institute at Ohio University recently conducted a comprehensive study on highway culvert structures for the Ohio Department of Transportation. During the study, a number of thermoplastic pipe structures under Ohio’s highways were inspected and rated. One of the thermoplastic pipe structures was a 0.61-m-diameter (24-in.-diameter) corrugated high-density polyethylene (HDPE) pipe under State Route 145 in Noble County, Ohio. What was unique about this pipe structure was that it was the oldest thermoplastic pipe culvert in service in Ohio. The pipe was installed under a shallow cover in 1981. The Ohio University team visited the culvert site in 2004 and inspected the pipe structure thoroughly. It was inspected again in June 2010. Drainage water entering the culvert was acidic, indicating the influence of a nearby surface coal-mining operation. The pipe structure had moderate amounts of deflection under the roadway, but overall it appeared to be in satisfactory condition. In 2004, a short pipe section was taken from the outlet end to determine if the pipe material had degraded over the years from constant exposure to ultraviolet light and acid mine drainage. A series of tensile strength and density tests were performed according to industry standard test methods. Test results showed that the thermoplastic pipe material experienced little aging. Finally, a course of action was recommended for the HDPE pipe structure based on a basic risk assessment analysis.

A database of dynamic modulus values for typical Superpave mixes widely used in the state of Washington was developed and used to investigate the sensitivity of the dynamic modulus to aggregate gradation. Seven job-mix formulas (JMFs) were selected for study. The percent of these mixes passing a No. 200 sieve was changed by $\pm 2\%$ to prepare additional mixes referred to as modified mixes. Statistical analysis showed that using different JMF mixes significantly affected the dynamic modulus. This was not the case when the JMF was modified by changing the percent passing a No. 200 sieve. A simple evaluation of the prediction accuracy of the new Mechanistic-Empirical Pavement Design Guide (MEPDG) was conducted in which the measured dynamic modulus was used as a key input parameter to predict pavement distresses. Level 1 and Level 3 predictions of rutting, longitudinal cracking, alligator cracking, and International Roughness Index (IRI) were compared with field performance data. The MEPDG predicted IRI and alligator cracking reasonably well. The predicted rutting of the JMF mixes agreed well with the dynamic modulus trend. It was found that in the modified mixes, aggregate gradation did not affect the predicted distress significantly.

Predicting performance of asphalt concrete (AC) overlay is important for both pavement design and management. Based on 328 AC overlay sections from the long-term pavement performance (LTPP) program, ordinal logistic regression models were developed in this study to predict the probability of severity levels for alligator cracking. It was found that the alligator cracking is significantly affected by alligator cracking of the existing pavement, thickness of overlay, thickness of the existing AC, age of pavements after resurfacing, truck volume, freeze-thaw cycles, and the amount of precipitation per wet day. In addition, it was found that the use of recycled asphalt pavement in the amount specified in the SPS 3 experiment and preoverlay treatment significantly affect overlay cracking. Both statistical conformance tests and empirical verification using independent data indicate that the developed models are reasonably accurate. The model can generate the probability of a pavement staying at a certain distress level and the odds ratio, which enables highway agencies not only predict probability of cracking but also assess the confidence of making such predictions.

On March 2, 1973, the Skyline Plaza apartment building in Bailey’s Crossroads, Virginia collapsed while under construction. The Occupational Health and Safety Administration (OSHA) requested an investigation from the National Bureau of Standards [(NBS); now the National Institute of Standards and Technology (NIST)]. The NBS team concluded that the most likely cause of the collapse was a punching shear failure of the 23rd floor slab. The two factors that contributed to this were premature removal of shores below the 23rd floor slab, and the low strength of the 23rd floor concrete in the area supporting the weight of the 24th floor slab. The engineer’s structural drawings required 2 full stories of shoring and 1 story of reshoring while a concrete slab was cast. The project architect and structural engineer were sued and held responsible, although their specific shoring instructions had been ignored. This case study reviews the available published information on the case to determine what lessons can be learned. The case is suitable for inclusion in variety of courses in the civil engineering and construction curriculum.

A successful engineering project must include its timely and economic completion. A project management failure can lead to delays and cost overruns. One example of a project that greatly exceeded its projected budget is the construction of the multiple facilities for the 1976 Olympic Games in Montreal. These included the Olympic Stadium, a velodrome for bicycle events, and the Olympic Village to house the athletes. This case study reviews the circumstances of the cost increases and the design decisions and other circumstances that led to them. The difficulties were brought on by an unrealistic schedule to complete the facilities before the fixed start date of the Games, combined with an unusually cavalier attitude toward project costs, exacerbated by political tensions. Although the original cost estimate for the facilities was $120 million, the final cost was $1.5 billion, with $830 million for the main stadium alone. Part of the justification for the expense of the facilities was the hope that the facilities would be useful for future athletic events—the record on this is mixed at best. The lessons learned can be applied to other projects to better control costs.