Review on Seismic Analysis of Multistoried Building in Hilly Region

Due to sloping land and high seismically active zones, designing and construction of multistory buildings in hilly regions is always a challenge for structural engineers. This review paper focuses to establish a review study on the Possible Types of building frame configuration in the hilly region and he behavior of Such building frames under seismic loading conditions, and (3) The recent research and developments to make such frames less vulnerable to earthquakes. This paper concludes that the dynamics characteristics of such buildings are significantly different in both horizontal and vertical directions, resulting in the center of mass and center of stiffness having eccentricity at point of action and not vertically aligned for different floors. When such frames are subjected to lateral loads, due to eccentricity it generates torsion in the frame. Most of the studies agree that the buildings resting on slanting ground have higher displacement and base shear compared to buildings resting on plain ground and the shorter column attracts more forces and undergoes damage when subjected to earthquake. Keywords: Building frame configuration, Seismic behavior, Dynamic characteristics, Response spectrum analysis, time history analysis.

Case Study to Evaluate Stresses in Welded Endplates in Structural Steel

Endplates are widely used in the industry to attach supplementary steel structures to main building frames. These endplates can be attached to the building steel using a bolted connection or a welded connection. Industry often favors bolted connections due to ease of installation and availability of qualification methods per AISC 360 Design Guides. However, there are some applications where a welded connection is preferable, such as, cases requiring reduction of number of parts supplied or applications with higher chance of vibration causing loosening of bolts. The present case study discusses evaluation of stresses in welded endplates due to forces and moments from the attaching supplementary steel members. The study considers various welded connection scenarios including an endplate welded on two opposite sides and an endplate welded on all four sides. The stress distribution in the plate is studied using finite element analysis with wide flange and tube steel members attaching to it. ANSYS mechanical is used to perform the finite element analysis. Multiple combinations of plate sizes, weld patterns, and attaching member sizes are analyzed to provide a well-rounded solution. An analytical model is developed for the stress evaluation as well and the results are compared with the finite element model. The study is intended to provide an efficient methodology for plate evaluation and qualification.

Cost Effective Design of RC Building Frame Employing Unified Particle Swarm Optimization

Present paper deals with the cost effective design of reinforced concrete building frame employing unified particle swarm optimization (UPSO). Two building frames with G + 8 stories and G + 10 stories have been adopted to demonstrate the effectiveness of the present algorithm. Effect of seismic loads and wind load have been considered as per Indian Standard (IS) 1893 (Part-I) and IS 875 (Part-III) respectively. Analysis of the frames has been carried out in STAAD Pro software. The design loads for all the beams and columns obtained from STAAD Pro have been given as input of the optimization algorithm. Next, cost optimization of all beams and columns have been carried out in MATLAB environment using UPSO, considering the safety and serviceability criteria mentioned in IS 456. Cost of formwork, concrete and reinforcement have been considered to calculate the total cost. Reinforcement of beams and columns has been calculated with consideration for curtailment and feasibility of laying the reinforcement bars during actual construction. The numerical analysis ensures the accuracy of the developed algorithm in providing the cost optimized design of RC building frames considering safety, serviceability and constructional feasibilities.Further, Monte Carlo simulations performed on the numerical results, proved the consistency and robustness of the developed algorithm. Thus, the present algorithm is capable of giving a cost effective design of RC building frame, which can be adopted directly in construction site without making any changes.