Journal of Performance of Constructed Facilities

The focus of the current study is to analyze previously reported test results to evaluate equivalent plastic hinge lengths for concrete-block shear walls and to extract related seismic performance parameters. Inelastic curvatures at the base of the walls are the main source of plastic deformation for flexurally dominated walls. With adequate estimation of the plastic hinge length and more realistic values for inelastic curvatures at the base of the wall, top wall displacement can be predicted more accurately. For the walls analyzed, measured compressive strains close to the base of the wall at maximum load were significantly higher than the strains specified by North American codes. The strains, although may not alter the wall strength, significantly affect the displacement ductility at maximum load. The analysis showed that the equivalent plastic hinge length varied between approximately 30 and 60% of the wall length at a drift of 1%. The product of the seismic force modification factors (for ductility and overstrength) varied between 3 and 6. The plastic hinge length and the seismic force modification factors were found to depend not only on the factors prescribed in North American codes but on the amount of vertical reinforcement and axial stress level as well. This study draws a road map for further research to facilitate better understanding and provide more realistic methods to predict the seismic performance of masonry shear wall construction.

It is known that in historical buildings as well as new buildings, facade claddings consisting of marble panels, are prone to damage patterns such as softening, crack formation, and bowing. The degree of damage is apparently dependent on the location of the building, the external climatic conditions, and the type of fastening of the facade panels. In this article, it is examined by means of nonstationary thermal simulation, to which extent the temperature fields, which develop in the facade panel, have an effect on the damage of the panel. It is shown that the diurnal and annual amplitude of the panel temperature induced by solar flux, external air temperature fluctuations, and long-wave input radiation and irradiation have a substantial influence on the damage process. On the example of the simulation of the thermal behavior of a facade panel for the building locations in Athens, Greece, Vienna, Austria, and Helsinki, Finland, it is shown that the observed increase of the susceptibility of marble facades to damages can be explained with the increase of the geographical latitude through the differences in the external climatic conditions. It is strongly recommended that architects and restorers install specific marble facade panels (like carrara marble) in close thermal contact with the wall behind, since this reduces the susceptibility of the facade to damage.

This research studies the feasibility and effectiveness of a new method of strengthening existing RC T-beams in shear by using mechanically anchored unbonded dry carbon fiber (CF) sheets. This method eliminates the debonding of epoxy-bonded carbon-fiber-reinforced polymer (CFRP) sheets and utilizes the full capacity of dry CF sheets. In this method, dry CF sheets are wrapped around and bonded to two steel rods. Then the rods are anchored to the corners of the web-flange intersection of the T-beam with mechanical bolts. This makes a U-shaped dry CF jacket around the web which increases the shear strength of the T-beam using the privilege of higher tensile strength and modulus of elasticity of dry CF compared to composite CFRP. A total of three RC T-beams with shear span-to-depth ratio of 2.0 were tested under increasing monotonic load till failure. The pilot tests were done as a proof-of-concept of the effectiveness of the proposed method in increasing the shear capacity of the RC T-beams. The first T-beam, which was tested as the control beam, failed in shear. The second beam was strengthened by using a U-shaped CFRP sheet that was externally bonded to the web of the beam in the shear zones. The third beam was strengthened by using anchored U-shaped dry CF sheet. The test results showed that the beam strengthened by the new mechanically anchored dry CF had about 48% increase in shear capacity as compared to the control beam and 16% increase in shear capacity as compared to the beam strengthened by CFRP epoxy-bonding method.

This paper describes the design and evaluates the adequacy of the moment connection of an experimental two-span highway bridge designed by the Tennessee Department of Transportation. The Massman Drive Bridge is an experimental design that unifies the construction economy of simple span bridges and the structural economy of continuous span bridges. The experimental connection, consisting of cover plates and kicker wedge plates, is used to connect the two adjoining girders over the center pier. As a result, the bridge is designed to function as a continuous bridge during the deck pour and behave compositely with the reinforced concrete deck under the live load. After completing a moment comparison analysis, it is concluded that the Massman Drive Bridge indeed acts as continuous over the pier as it was designed.

This paper presents the analytical modeling, modal testing, and finite-element model updating for a two-span masonry arch bridge. An Ottoman masonry arch bridge built in the 19th century and located at Camlihemsin, Rize, Turkey is selected as an example. Analytical modal analysis is performed on the developed 3D finite-element model of the bridge to obtain dynamic characteristics. The ambient vibration tests are conducted under natural excitation such as human walking. The operational modal analysis is carried out using peak picking method in the frequency domain and stochastic subspace identification method in the time domain, and dynamic characteristics (natural frequencies, mode shapes, and damping ratios) are determined experimentally. Finite-element model of the bridge is updated to minimize the differences between analytically and experimentally estimated dynamic characteristics by changing boundary conditions. At the end of the study, maximum differences in the natural frequencies are reduced on average from 18 to 7% and a good agreement is found between analytical and experimental dynamic characteristics after finite-element model updating.

To develop a defense strategy to protect power transmission lines against blast-induced ground motions, an understanding of the dynamic responses of these structures must be first established. This paper presents the results from ground motion monitoring at two blast sites in southern United States. These studies are being conducted as part of a research effort to establish strong ground motion characteristics necessary for developing blast limits for power transmission systems. Ground movements caused by the surface mining blast and quarry blasting were recorded using geophones and wireless triaxial sensing units. The process of establishing the ground motion response spectra via analyzing actual ground motion measurements, including noise filtration and signal processing, is then described. These ground motion response spectra are the necessary inputs for spectrum analysis of structural responses that can be used to establish ground vibration limits.

To ensure power transmission safety, loss of structural integrity of critical transmission facilities due to extreme events, such as strong ground motions induced by blasting, should be avoided. This research intends to establish a vibration safety limit for electric power transmission poles close to blasting events through actual field monitoring and finite-element (FE) simulation of transmission structure dynamic behaviors. In this paper, structural responses of transmission poles during monitored blasting are used to illustrate the methodology for safety limit establishment. The blast response spectra generated based on peak particle velocities were used as a basis for spectrum analysis performed using validated FE models to obtain the structural displacements, reactions, and stress states. The actual recorded ground vibrations as well as modified acceleration time histories were used as input excitations during transient dynamic analysis. A quantitative blast limit was established by comparing structural responses with corresponding design requirements.

In gulf region countries like Kuwait, the construction process can become very challenging. In this paper, we analyze construction-related accidents in Kuwait including type of accident, type of injury, body part injured, and accident outcome for the years 1996–2007. We present examples of recent cases and evaluate these cases presenting current Kuwaiti rules and legislation and providing suggestions for ensuring a safer construction environment. As this research shows, the construction industry is the most hazardous industry in Kuwait. On average, falls are the major type of accident (33.2%) followed by being crushed or struck by a falling object (25.2%). Use or misuse of tools caused the third largest number of accidents in Kuwait (18.1%). The most frequent type of injury is fractures (52.6%) and the most common injured body part is the upper body (53.4%). An average of (82.7%) of victims of construction accidents in Kuwait sustain permanent disabilities. It is clear that the Kuwaiti construction industry has a safety problem and that there is a pressing need to change current practices and legislation in construction and building sites.

This paper provides insights from a graduate forensic engineering course for civil engineers and analyses its success from the instructor and student perspectives. The objective of the study was to evaluate teaching methods and settings for training of forensic engineers in light of new body of knowledge needs for the profession. The assessment methodology used student feedback before, during, and after the semester-long course and the instructor’s observations and prior forensic engineering consulting experience. The course was structured around student learning objectives that paralleled actual engineer training in professional consulting firms. The students used hands-on learning, field investigations, library-based research, and report writing. Focus was placed on learning basic research skills and applying scientific method which were at low levels among students. This is of concern to the profession as these skills, along with analytical ability, form part of the basic tool set of most engineers. By the end of the course, writing and review skills had improved significantly and student perceptions of the specialized skills turned more favorable. The students overwhelmingly appreciated inclusion of guest lectures by forensic engineers to demonstrate the relevance of this field. It was concluded that inadequate technical writing and reading skills, symptomatic of students in many engineering programs can be corrected through a forensic engineering course.

With an inclinometer casing mounted on a sheet pile wall in peat bogs, sheet pile wall deflections were measured during a trial deep dynamic compaction (DDC) test. Analyses of the trial testing data indicated that sheet pie wall deflections were significantly affected by the tamping distance, $X$ , (horizontal distance between tamping points and sheet pile walls). The DDC-induced wall deflections can be simulated by an exponential relationship related to $X$ . The trial testing results were verified by the finite-element (FE) simulation. The FE analyses indicated that sheet pile wall deflections were linearly proportional to the impact energy per blow, $E_i$ . The analyses of surveyed data showed that sheet pile wall deflections due to DDC were also related to the ratio of the wall penetration depth in the underlying sands, $d_S$ , to the wall height, $L$ . Based on these findings, a semiempirical approach, incorporating the key factors that govern the sheet pile wall deflections during DDC, was developed. The estimated wall deflections using this developed method were in reasonable agreement with the field measurements.