TO STUDY FLAT PLATE STRUCTURAL SYSTEM AND COMPARE IT’S BEHAVIOR WITH MOMENT RESISTING FRAME AND SHEAR WALL SYSTEM UNDER LATERAL LOADS

Abstract

In the present scenario, the buildings being constructed in India are increasing in Heights. The metropolitans are witnessing higher and higher towers with each coming day. Though, the average height of these new buildings may be ranging between 25-30 stories, there are a number of structures which are fairly high and need better structural understanding to give economical and safer designs. Majority of structures in India are based on the traditional Moment resisting frame concept in which the beams and columns cater to the gravity loads as well as the lateral loads by virtue of its moment resisting capacity. But this system is not efficient for buildings with heights greater than 15 stories. Hence, a different concept of shear wall is being widely used as a suitable alternative. With shear walls lateral force resisting capacity of buildings is improved drastically. With the use of shear wall structural system together with special moment resisting frame or with ordinary moment resisting frame the height of building has increased to 30 stories. But, in order to achieve economy, aesthetics and architectural requirements a new structural system which comprises of only slab and column mechanism is being looked upon. This structural system is called as flat plate system in which the thickness of slab remains constant and columns rest directly on the slabs without any drops or beams. This system not only has an aesthetic edge over traditional beam-column system or flat slab system, but also proves to be economical because of lower construction time and lesser storey height. In this paper we have studied the behavior of flat plate system with increase in height. The study comprises of buildings with and without shear wall systems. The problem areas of using flat plate system have been discussed in this paper, which primarily comprise of unbalanced moment transfer of moment from column to slab, and lesser stiffness of the building as a whole to resist lateral loads. The behavior of flat plate system has also been compared with the traditional beam column moment resisting frame system and their differences have been studied. Analysis of Flat plate under gravity loading has also been performed in computer software and is compared with the direct design method of IS 456. Future scope of this paper includes economical comparison of the moment resisting frame structure and flat plate structure.