Dipendu Bhunia

A Conceptual Design Approach of Coupled Shear Walls

Earthquake causes considerable damage to a large number of RCC high-rise buildings and tremendous loss of life. Therefore, designers and structural engineers should ensure to offer adequate earthquake resistant provisions with regard to planning, design, and detailing in high-rise buildings to withstand the effect of an earthquake and minimize disaster. As an earthquake resistant system, the use of coupled shear walls is one of the potential options in comparison with moment resistant frame (MRF) and shear wall frame combination systems in RCC high-rise buildings. Furthermore, it is reasonably well established that it is uneconomical to design a structure considering its linear behavior during earthquake. Hence, an alternative design philosophy needs to be evolved in the Indian context to consider the postyield behavior wherein the damage state is evaluated through deformation considerations. In the present context, therefore, performance-based seismic design (PBSD) has been considered to offer significantly improved solutions as compared to the conventional design based on linear response spectrum analysis.

Mechanical strength and durability of mineral admixture concrete subjected to accelerated carbonation

Abstract Based on the experimental evaluation of blended cement concretes, its vulnerability to the potential carbonation threats have been discussed in this paper. Water binder ratios of 0.35, 0.50, and 0.65 have been adopted to study the mechanical properties and durability of the concrete mixes exposed to accelerated carbonation. Equations to predict the depth of carbonation under controlled conditions for these mixes have been established. The reliability of square root t law of diffusion to address the ingress of carbon dioxide into concrete has also been studied. Furthermore, conclusions have been drawn that the addition of fly ash and blast furnace slag as a partial replacement of cement decreased the carbonation resistance of concrete unless a water binder ratio of 0.35 is used, in which case the depth of carbonation remained almost same.

Investigation into the Behavior of Coupled Shear Walls

An effective design technique for symmetrical coupled shear walls is presented in this paper. The proposed formulation, including assumptions and steps with mathematical formulation, has been elaborated to arrive at the design technique. An example has been considered to validate the technique with the DRAIN-3DX and SAP non-linear analysis. A parametric study has also been considered to find out the limitations of this technique and suggest remedial action. It is concluded that the proposed design technique can be considered in the design of coupled shear walls under seismic motion.