In the current research work, an attempt is made to increase the seismic capacity of unreinforced masonry (URM) structures by proposing a new composite material which can improve shear strength and deformation capacity of URM wall systems. Fiber Reinforced Polymer (FRP) having high tensile and shear stiffness can significantly increase in-plane and out-of-plane strength of masonry walls, but, inherently, FRP strengthened wall systems exhibit brittle failure under extreme seismic loading. Polypropylene (PP-band) is a low cost material with sufficient ductility and deformation capacity. Keeping in view the behavior of FRP and PP-band, a composite of FRP and PP-band is proposed for retrofitting of URM walls. Mechanical behavior of the proposed composite material is assessed by carrying out an in-plane diagonal compression test and an out-of-plane bending test on twenty-five 1/4-scaled masonry wall panels. Experimental plan for each panel, URM, PP-band retrofitted, FRP retrofitted and FRP + PP-band retrofitted masonry, is diagonal compression test and three-point bending test. Experimental results have determined that FRP + PP-band composite increased, not only the initial peak strength, but also the ductility, deformation capacity and residual strength of URM wall systems.

The current study is devised to evaluate the seismic performance of fiber-reinforced polymer (FRP) retrofitted buildings with openings at different FRP reinforcement levels. Required objectives are achieved by performing five shake table tests on 1/4-scale models of single-story boxlike masonry buildings. Out of five building models, one was an unreinforced masonry (URM) building model whereas the other four were retrofitted with different quantities and layouts of FRP reinforcement. FRP reinforcement is reduced by decreasing FRP strip widths and strip spacing and applying FRP strips on either the inside or outer faces of walls. Each building model was subjected to the same series of input ground motions with gradually increasing amplitudes. A series of diagonal compression tests was also conducted to decide the appropriate type of FRP and trial FRP reinforcement ratios for the masonry building models. Descriptions of the tested models are provided, including the structural response in terms of ba...

Severe failure of improperly designed and poorly constructed structures may occur due to the amplified and prolonged ground motion during an earthquake, and hence prediction of the ground motion characteristics at the soil surface is crucial. In this study, based on the prepared simplified engineering geomorphic map, we performed a one-dimensional (1D) nonlinear site response analysis for seismic site characterization of the recently proposed Detailed Area Plan (DAP) area of Dhaka City, the Capital of Bangladesh. The engineering geomorphic unit-based map was prepared from image analysis and verified with the collected borehole data and surface geology map. The study area was classified into three major geomorphic units and seven sub-units subject to the subsurface soil profiles. Nine earthquake time histories, seven from the PEER NGA WEST2 data set and two synthetics, and seven identified subsurface soil profiles were used for nonlinear site response analysis, along with the BNBC 2020 uniform hazard spectrum as the target spectrum. For the selected earthquake ground motions, the near-surface soil response of the DAP area showed de-amplification of acceleration in the short period and amplification of acceleration in the long period. The amplified long-period acceleration could cause severe damage in inappropriately designed and poorly constructed long-period structures. The outcome of this study could be used to prepare a seismic risk-sensitive land use plan for the future development of the DAP of Dhaka City.

The purpose of this study is to develop a support system for planning human resource allocation of shelter management by modeling the matching between the shelter and the staff on the basis of the set theory approach to enable sufficient days off, reduce long work hours, and consideration for appropriate rotation without causing the mental and physical deterioration of the shelter management staff. Using this matching model, a basic study was conducted to determine the appropriate human resource allocation to manage the shelter with a small number of staff members, free from unbalanced work days. The study results elucidate the relationship between the number of possible consecutive work days and that of required consecutive days off. In addition, the human resource allocations with experience in shelter management and the setting method of days off were modeled and their results are presented in this study.

To establish a standard operation procedure (SOP) for shelter management, this research analyzed current situations about shelter management in Japanese local governments, focusing on designation of shelters, operation manager and information sharing. The results indicate that some have non-designated shelters, which might lead to differences of support with designated shelters, local governments ask residents to operate shelters mainly, but this requirement is not shared among them, and system of information sharing is not developed primarily with the department of health and welfare. Besides, this research shows the importance of including the closing and after the closing of the shelters.