PCI Journal Paper Title: Preliminary results of the shake-table testing for the development of a diaphragm seismic design methodology

Due to the increased demands of adapting the sustainability concept in the construction industry, many researchers have developed and evaluated the composite materials made with agricultural by-products, such as straws, fruit-shells, and cobs, as construction materials. Because no research work has been reported regarding the incorporation of common reed fiber (CRF) into a concrete composite to produce the green and sustainable concrete, this research has focused on the evaluation of physical, mechanical, and thermal properties of mortar mixture containing CRF regarding density, porosity, compressive and flexural strengths, and thermal conductivity. In total, six mixtures with 0%, 2%, 4%, and 6% CRF; 0.5% steel fiber (SF); and the combination of 6% CRF and 0.5% SF were prepared. Based on the experimental outputs, a simple analysis of heat loss was also been performed. The test results presented that the incorporation of CRF into mortar mixture proportionally reduced its unit weight and significantly increased its absorption capacity and porosity. Although the use of only CRF in the mortar mixture did not improve both compressive and flexural strengths compared to the plain mixture, the combined use of CRF and SF to increase both compressive and flexural strengths generated a synergetic effect to increase both strengths. The addition of CRF to the mixture has the benefit of producing a significant decrease in heat loss for a typical building in Astana due to the lower thermal conductivity and higher porosity to density ratio.

Summary: This paper presents the development of a deformable connection that is used to connect each floor system of the flexible gravity load resisting system (GLRS) with the stiff lateral force resisting system (LFRS) of an earthquake‐resistant building. It is shown that the deformable connection acts as a seismic response modification device, which limits the lateral forces transferred from each floor to the LFRS and allows relative motion between the GLRS and LFRS. In addition, the floor accelerations and the LFRS story shears related to the higher‐mode responses are reduced. The dispersion of peak responses is also significantly reduced. Numerical simulations of the earthquake response of a 12‐story reinforced concrete shear wall example building with deformable connections are used to define an approximate feasible design space for the deformable connection. The responses of the example building model with deformable connections and the example building model with rigid‐elastic connections are compared. Two configurations of the deformable connection are studied. In one configuration, a buckling restrained brace is used as the limited‐strength load‐carrying hysteretic component of the deformable connection, and in the other configuration, a friction device is used. Low damping laminated rubber bearings are used in both configurations to ensure the out‐of‐plane stability of the LFRS and to provide post‐elastic stiffness to the deformable connection. Important experimental results from full‐scale tests of the deformable connections are presented and used to calibrate numerical models of the connections. Copyright © 2016 John Wiley & Sons, Ltd.

Wireless smart sensors (WSS) have been proposed as an effective means to reduce the high cost of wired structural health monitoring systems. However, many damage scenarios for civil infrastructure involve sudden events, such as strong earthquakes, which can result in damage or even failure in a matter of seconds. Wireless monitoring systems typically employ duty cycling to reduce power consumption; hence, they will miss such events if they are in power-saving sleep mode when the events occur. This paper develops a demand-based WSS to meet the requirements of sudden event monitoring with minimal power budget and low response latency, without sacrificing high-fidelity measurements or risking a loss of critical information. In the proposed WSS, a programmable event-based switch is implemented utilizing a low-power trigger accelerometer; the switch is integrated in a high-fidelity sensor platform. Particularly, the approach can rapidly turn on the WSS upon the occurrence of a sudden event and seamlessly transition from low-power acceleration measurement to high-fidelity data acquisition. The capabilities of the proposed WSS are validated through laboratory and field experiments. The results show that the proposed approach is able to capture the occurrence of sudden events and provide high-fidelity data for structural condition assessment in an efficient manner.

Tall buildings are being built for more than a century now, but there has been an exponential growth in the development of convoluted tall buildings with distinctive architecture. A tall building with a unique structural form, brings forth admonishing challenges for the structural designers to deal with. Such a contemporary inclination towards the fabrication of free-form structures has posed enormous challenges to the modern-day structural engineering community, and consequently, has faced reactions in the form of tremendous researches pertaining to complex building specific issues. This paper extensively reviews six case studies of recent tall buildings that possess a challenging architecture with tortuous structural features to cope with the gravity and lateral loadings. Six representative tall buildings have been chosen from all over the world, which have distinctive features in terms of their structural systems. This paper discusses the fundamental characteristics of these tall buildings in the world and presents the challenges faced during the modelling, analysis, design, and construction of these skyscrapers, along with the brief of methodologies which were eventually adopted to cope with these challenges.