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In this paper, the cyclic behavior of groups of double-headed anchored blind bolts (DHABBs), which are anchored within concrete-filled square hollow sections (CFSHSs), is investigated. The ...

Masonry infill walls significantly contribute to the seismic demand imposed on RC buildings. However, in general, infill walls are considered as nonstructural elements in seismic design and...

Reinforced concrete (RC) impact-resistance barriers, such as rockfall barriers, often consist of a cantilever RC wall, which is expected to experience flexural bending under impact loading ...

In this paper, a new design approach based on the principles of energy and momentum conservation is proposed for the design of free-standing rigid barriers subject to point impact. The nove...

Seven full-scale curved T-stubs connected to concrete-filled circular hollow sections (CFCHSs) using groups of double-headed anchored blind bolts (DHABBs) have been cyclically tested in thi...

This paper provides a unique literature review of cracking defects developing in low-rise residential structures as a result of deformation caused by environmental loads and low-level blast...

In this paper, the tensile behavior of groups of Ajax anchored blind bolts used within concrete-filled steel square hollow sections is investigated. Using Ajax anchored blind bolts moment-resisting bolted connections to concrete-filled steel hollow section columns will be possible. Extensive experimental and numerical studies were undertaken. Bolt sizes and section sizes suitable for medium-rise commercial buildings were used. It was concluded that the groups of Ajax anchored blind bolts can reach the ultimate capacity of equivalent groups of standard structural bolts. The location of an Ajax anchored blind bolt relative to the section side walls has a significant influence on its behavior. For bolts located close to the side walls of a section, concrete struts developed and transferred the loads to the corner of the sections. Bolt diameter, concrete grade, and strut angle were found to be the most influential factors in the stiffness of an Ajax anchored blind bolt. A simple theoretical model, bas...

Annealed glass is by far the most commonly used glazing material in building construction. The resistant properties of glazing panels to wind loading has been studied for a long time based on quasistatic modeling. More recently, the vulnerability of infrastructure and its protection against acts of terrorism has been receiving a great deal of attention, as pioneered by the work of Wu and Hao from within Australia, whereas vulnerability studies by Stewart were specific to glass facades in terrorism scenarios. Emphasis has been on modeling the blast induced pressure and impulses, as they are applied to the panels while the resistant properties of the glazing materials have been based on assumptions used currently in design. Research undertaken by the writers over the past two to three years have revealed scopes of possible improvements to the current models that have been used in defining the resistant properties of glazing materials. Models based on the well known Weibull distribution, although widely assu...

This paper presents the results of two series of experimental and analytical studies on the structural behavior of an innovative moment-resisting connection to concrete-filled circular hollow sections using blind bolts. The first part of the paper presents a large-scale T-stub connection with full instrumentation tested to failure in tension, and the second part presents a series of pullout tests to explore the anchorage behavior of cogged bars within concrete-filled steel tubes. The favorable strength and stiffness characteristics of this type of connection showed that it could be an alternative to conventional welded moment-resisting connections. A 3D finite-element (FE) model was developed to simulate the behavior of blind-bolted T-stub connections when subject to tension. The FE model took into account material nonlinearities, geometrical discontinuities, and complex contact interactions among the bolt heads, tube wall, end plates, and nuts. The FE results were found to be in good quantitative agreement with the actual connection behavior. A stiffness model composed of various nonlinear springs was also developed to predict the pullout behavior of cogged bars within concrete-filled steel tubes. The cogged extensions to the blind bolts were very effective in relieving the stress concentration on the thin tube wall. The tensile load can be shared between membrane action of the tube wall and anchorage of the cogged bars. Thus, by using the blind-bolted connections with cogged extensions to connect the beam flanges to the column, moment transfer between the beam and column can be effectively achieved within a structural frame of composite construction.

Component failures in water distribution systems are usually predicted by parametric models where the model parameters are determined by projecting the past failure rates of the component to the future. This paper shows that in such techniques, failures are implicitly assumed to be stationary random processes. However, due to the nonstationary nature of some influencing factors, this assumption may lead to inaccurate predictions. A new nonparametric technique is developed for failure prediction of classes of pipes considering this nonstationary process. The presented technique uses limited data that are typical to the databases of water distribution systems. In this method, maximum likelihood estimates of the probability of future failures are calculated and used, both to predict the number of failures occurring within a specified period of time in future, and to provide some lower and upper bounds (confidence intervals) for the estimations. This technique is applied to predict the failures of water pipes in western suburbs of Melbourne. Results of the predictions are compared with the empirical results from a failure record. Deviation of these predictions from empirical measures in terms of both rejection rates and mean-square errors of predictions are acceptable.

Blasting is common in the coal industry to remove rock overburden so that the exposed coal can be mechanically excavated. The ground vibrations and air blast produced by blasting are often felt by residents surrounding the mines. There has been a trend for regulatory authorities, especially those concerned with the environment, to impose low limits on blast vibration levels in response to community pressure, based on human perception and response to vibration. This paper reports the findings of an extensive study on a house which was located adjacent to a coal mine. The house was monitored for over 1 year and was subjected to ground peak particle velocity (PPV) ranging from 1.5 to 222 mm/s. The house was instrumented with accelerometers to measure its dynamic response due to blasting and it was also monitored for cracks before and after each blast. Based on this study, ground motion amplifications along the height of the structure have been established. A simplified methodology presented in this paper has been used to estimate the ground PPV at which cracking is likely.

The Australian Residential Timber-Framed Construction standard (AS1684:1999) has recently been revised to explicitly define the bracing contribution of nominally fixed plasterboard clad walls as 0.45 kN/m for cladding on one side and 0.75 kN/m for cladding on two sides. These values clarify the allowance, which designers may rely upon for the presence of plasterboard and their inclusion in the standard infers a necessity for plasterboard products to at least meet these requirements. A review of the relevant Australian, ISO, and ASTM standards, as well as plasterboard manufacturers' in-house quality control tests has established that these tests mainly focus on serviceability aspect of plasterboard (e.g., storage, transportation, and installation) rather than that of structural bracing performance. It has also been determined that there are no direct correlations between serviceability conditions and structural bracing performance of plasterboard. In fact, a limited set of data provided by the plasterboard manufacturers shows that almost no correlation exists between the current quality control tests and the most commonly measured parameter, the density of plasterboard. It has been concluded that current tests are inadequate to serve as control measures for bracing performance of plasterboard. Nonetheless, it must be noted that density is not the only parameter that may influence the bracing performance of plasterboard; other parameters such as linerboard strength and bonding between gypsum and linerboard may also affect the bracing capacity. This paper details a new test, termed fastener bearing test, which provides a method to evaluate the bracing capacity of plasterboard. The results of this test show a very high correlation with shear connection tests. The proposed test is practical and simple to perform as part of the manufacturing process, in addition to the current tests, without severe cost and time penalty to the plasterboard manufacturers.

The point fixed glass facade system (PFGFS), also known as a spider glass system, is popular because it is the most transparent facade system available for buildings. The glass facade system is fixed to the support structure at minimal points using bolts and spider arms. Generally, the racking performance of these systems is not considered at the design stage. The facade system will be vulnerable to racking actions mainly during severe earthquakes and wind actions if the system does not have sufficient in-plane drift capacity. A unique real-scale in-plane racking laboratory test on a typical PFGFS was conducted to assess the in-plane racking performance. A maximum drift of 2.1% was measured, which was much larger than initially anticipated because of the rigid-body articulation of the system and higher than typical maximum allowable interstory drift for buildings in regions of lower seismicity. A sophisticated nonlinear finite-element (FE) model was developed and conservatively benchmarked against...

This paper presents a detailed investigation into the contribution of plasterboard to the lateral resistance of cold-formed steel-framed residential structures. It details the development of a finite-element model for laterally loaded plasterboard-lined cold-formed steel wall frames for residential construction. The model utilizes nonlinear element properties and three-dimensional geometrical configurations and is capable of simulating the influence of boundary conditions such as corner return walls and ceiling cornices. The analytical results from the finite-element model were successfully verified against experimental racking test results. A sensitivity analysis was conducted using the model to study the influence of return walls, ceiling cornices, and wall length on the lateral capacity of the wall system. It is concluded that a wall with corner return walls, ceilings cornices, and skirting boards has more than three times the lateral capacity of an identical isolated wall panel. The relationship between the wall length and the ultimate lateral load-carrying capacity of the wall system is dependent on the presence of these boundary conditions.