Journal of Performance of Constructed Facilities

Hurricanes present a serious financial threat to the Gulf Coast and eastern seaboard of the United States. This paper is the first in a set of companion papers that detail a comprehensive mechanistic loss model for wind and rainwater intrusion damage to light-frame wood buildings. In this paper the structural and hazard modeling for a passing hurricane is explained and demonstrated. The structural model consists of a nonlinear nail model integrated into a finite-element model, and a hazard model is developed using a combination of existing wind tunnel data and a rainwater intrusion model. A methodology to compute the rainwater entry volume is presented. The approach differs from previous methods in that it allows any time period to be examined by dividing the hurricane passage period into smaller increments of time and allows both load and resistance to change from time period to time period. Thus, the time and location of damage and rainwater intrusion is known. The companion paper utilizes the volume of rainwater calculated herein and presents a systematic mechanistic approach to damage state modeling and the related financial loss.

This is the second paper in a set of companion papers. The first paper focused on modeling the hurricane hazard and the methodology to compute the volume of rainwater entering a roof system during a hurricane. This second paper explains a methodology to probabilistically compute losses beginning with the type and location of damage and volume and location of rainwater intrusion into the roof system. The ability to identify each contribution to damage and monetary loss is a necessary condition for development of performance-based wind engineering, thus providing the impetus for this second paper. The methodology summarized in this paper is capable of tracking damage and the individual damageable component contributions to the total loss probability. An illustrative example that compares losses for the same light-frame wood residential structure introduced in the first paper is presented. In addition, both damage and loss probability distributions are presented for each room in the structure, as well as for each damageable component. The results are felt to be reasonable and align qualitatively with logic considering the size of the hurricanes and geographical location of the structure. The approach has applicability in design code refinement and development, sensitivity studies for improved building products, and land use and planning investigations.

Metal-plated wood truss systems may be rained upon during the construction phase, resulting in the soaking of the connections. In this paper, the results of an investigation of the behavior of metal-plated wood joints subjected to periods of soaking are presented. The wetting regimes included (1) 4-h shower, (2) alternating cycles of a period of shower wetting followed by a period of no shower, and (3) 24-h soaking in a water tank. Results of tests conducted after wetting and after wet-dry cycles were compared with results of dry control tests. The results show the wet joints lost over 40% of their load-carrying capacity in all three wetting regimes. Upon drying, the strength loss was about 10%. Likewise, the stiffness of the joints deteriorated, with stiffness loss ranging from 12 to 37%. In contrast to the load-carrying capacities, there were insignificant recoveries in joint stiffness upon the drying of the specimen, with additional loss of stiffness during the drying process in one of the groups investigated. The results of this study suggest the need to warn against severe wetting or to compensate for this probability of occurrence in truss design standards.

Early-age cracking of base restrained concrete walls is a common problem. To provide the owner with an early warning of in-place quality problems resulting primarily as a result of thermal and shrinkage effects, it is helpful to apply monitoring and analytical techniques to examine the early-age behavior of basement concrete walls. In this paper, the temperature and strain monitoring on a basement concrete wall is conducted. Major factors that contribute to the early-age behavior of concrete walls constructed in cold weather are evaluated using analytical models along with measured field data and finite-element modeling. The results show that the monitoring process eliminated much of the guesswork frequently associated with basement concrete walls constructed in cold weather. Temperature varies laterally within the wall. The strain remains unchanged after six days with formwork removal. And the numerical predictions for strains and temperature are in agreement with the measured results, during both the cooling and the heating phases. This analytical method can be applied to newly constructed basement walls because they are often built several weeks after the slab foundation.

This paper studies performing progressive collapse analysis for steel structures using the requirements of recent codes released by the U.S. Department of Defense and the General Services Administration. Based on a review of the code requirements, the nonlinear dynamic progressive collapse analysis resulted in a more uniform factor of safety than the linear static analysis. The applied element method in the structural analysis is proposed as an efficient alternative for performing progressive collapse analysis. A case study is undertaken where the results of the progressive collapse analysis using traditional finite-element-method simplifications are compared with the results from the applied element method in the analysis of a moment-resisting steel frame. The case study shows that simplifications that are usually done in finite-element analysis when studying traditional load cases can be overconservative when performing progressive collapse analysis. The results show that the use of the nonlinear dynamic applied element method, while taking into account the effect of secondary members such as slabs and secondary beams, can lead to considerable savings in the total weight of the steel frame.

The Berke Arch Dam is the highest arch dam constructed in Turkey. The dam height is 201 m, and the crest length is 270 m. This paper describes the Berke Arch Dam, its finite-element modeling, ambient vibration testing, finite-element model calibration, and earthquake behavior before and after model calibration. First, three-dimensional (3D) models of dam-reservoir-foundation interaction were developed to obtain analytical dynamic characteristics, such as natural frequencies and mode shapes using the Ansys finite-element program. In the analyses, reservoir water was represented by a Lagrangian approach. Then, ambient vibration tests were conducted on the dam on 4 days in May 2009 to obtain experimental dynamic characteristics. In ambient vibration tests, the sensitive accelerometers were placed on several points on the arch dam, and signals were collected from accelerometers. The enhanced frequency domain decomposition technique was used in the extraction of experimental natural frequencies, mode shapes, and damping ratios. After that, 3D finite-element models of the Berke Arch Dam were calibrated using ambient vibration test results. Finally, earthquake behaviors of initial and calibrated models of the Berke Arch Dam were obtained using the Adana-Ceyhan Earthquake in 1998. It was observed that model calibration affects the results considerably.

The use of mechanically stabilized earth (MSE) retaining walls has gained popularity as an alternative to conventional cast-in-place concrete walls. The construction of MSE walls is cost effective, requires less site preparation, and is technically more feasible compared with conventional concrete retaining walls. However, use of backfill with high fine content and poor drainage behavior can cause excessive wall movement or even failure. The current paper presents the case study of a MSE wall located at State Highway 342 in Lancaster, Texas. The top of the MSE wall has moved as much as 300–450 mm only 5 years after construction. An extensive site and laboratory investigation testing program was conducted to determine the possible causes of the MSE wall movement. The site investigation included soil test boring and resistivity imaging (RI). Perched water zones were identified at a few locations in the backfill area using RI. The bulging of the MSE wall facings was observed where the perched water zones were located. Laboratory testing of the collected soil samples was conducted to determine the characteristics of the backfill soil. The test results indicated the backfill soil was clayey sand according to the Unified Soil Classification System. Based on the test results and analyses, it was determined that the presence of high fine content may have caused the excessive movement of the MSE wall. The movement of the MSE wall was also modeled using the finite-element program PLAXIS, and is presented in this paper. The actual movement of the MSE wall and the obtained movement from the model were in good agreement.

This paper reports the outcomes of a study of the vehicle crossing effects on a terrestrial light detection and ranging (LIDAR) scan on highway bridges for underclearance measurements. Ground-based or vehicle-mount terrestrial LIDAR scanners, which recreate the bridge structure as a three-dimensional point cloud of thousands of position data points, have been found to be ideal for bridge clearance measurements. To determine the effects of ambient overhead vehicle crossing and seasonal temperature variation on clearance measurements, periodic monitoring of the Harris Road Bridge has been conducted. A simplistic but practical correlation analysis is performed, which shows that operational LIDAR scanning is a viable technique for bridge clearance measurements.

To provide a certain level of serviceability, road authorities need to perform appropriate and timely maintenance and rehabilitation (M&R) activities. However, the vast expanse and different deterioration properties of road systems greatly increase the complexity of M&R activities. Because of lack of funding and resources, it is almost impossible for road engineers to monitor every road and to promptly maintain and rehabilitate any defects that have been identified. Therefore, the monitoring and reporting of defects by the public are becoming indispensable. For several years, location-based services (LBSs) have been applied to mobile devices with mobile positioning functions to provide users with location-specific services. Augmented reality (AR) can support users in manipulating virtual objects in real environments. In this study, a road monitoring and reporting system (RMRS) is developed including a mobile RMRS (an Android application) on smartphones and a web-based RMRS by integrating LBS and AR technologies. By using LBS and AR technologies, the time and costs of M&R activities can be significantly decreased, because routes of M&R activities can be planned in advance and the neighboring defects can be instantly identified and processed, which conforms exactly to the current policies of the Public Oversight of Public Works Projects and Smooth Roads Project in Taiwan. By using field data from Ilan County in Taiwan and considering the indefinite delivery contract, different strategies for M&R operations derived from the mobile and web-based RMRSs are analyzed. The results are presented to demonstrate the system’s benefits, costs, and feasibility.

Some damages observed in tunnels constructed with tunnel-boring machines are caused by contact deficiencies between segments, which are the result of the sum and accumulation of several types of tolerances. Because the relation among the tolerances, the contact deficiencies, and the structural damage is not quite clear, the segmented lining is usually designed to meet very tight tolerances. The existing tolerance recommendations consist mostly of extrapolation of tolerances applied to other types of concrete structures with different characteristics. This explains the wide variation of production tolerances found in the literature, with different repercussions on the cost of molds and on the performance of the structure. The first part of this study shows the relation between structural damage and contact deficiencies. The second part of the study explains how the contact deficiencies found in practice are generated by the tolerances. Finally, a general design method is proposed for the estimation of the production tolerances. Based on this, general recommendations are derived for the maximum admissible production tolerance used to limit the incidence of structural damage.

A four-stage procedure for effective management and maintenance scheduling for infrastructural facilities is presented. The structure/component needing immediate attention is identified during the first stage. The second stage investigations reveal local or global damage and also the location of damage, based on the principles of damage assessment. Nondestructive testing and evaluation form the third stage. In the last stage, repair and remedial measures are carried out, which are followed by testing, if necessary. Out of the case study examples presented, two are specific to the third and fourth stage evaluation only, while one case study example is explained in full.