Issue 10

A.Namdar et alii, Frattura ed Integrità Strutturale, 10 (2009) 38-42; DOI: 10.3221/IGF-ESIS.10.05 38 Numerical analysis of soil bearing capacity by changing soil characteristics Abdoullah Namdar Mysore University, Mysore, India, sina_a_n@yahoo.com Mehdi Khodashenas Pelko Amirkabir University, Tehran, Iran A BSTRACT . In this research work by changing different parameters of soil foundation like density, cohesion and foundation depth and width of square foundation at angle of friction of 0  to 50  with increment of 5  , numerically safe bearing capacity of soil foundation is calculated and it is attempted to assess economical dimension of foundation as well as understanding variation range of bearing capacity at different degree. It could help of civil engineering in design of foundations at any situation. K EYWORDS . Safe bearing capacity, Density, Cohesion of soil (c), Angle of friction (φ) and Dimension of foundation I NTRODUCTION mprovement of soil foundation is a method to disabling earthquake forces and stabilization of soil foundation. For achieving this aim designing a series of foundations by changing gradually the main parameters of soil is the shortest way to better understanding soil characteristics. It has been reported the effect of soil confinement on the behavior of a model footing resting on sand under eccentric – inclined loa d [1]. Rea and Mitchell conducted a series of model plate loading tests on circular footings supported over sand-filled square-shaped paper grid cells to identify different modes of failure and arrive at optimum dimensions of the cell [2]. Mahmoud and Abdrabbo presented an experimental study concerning with a method of improving the bearing capacity of strip footing resting on sand sub-grades utilizing vertical non-extensible reinforcement. They found out this type of reinforcement increases the bearing capacity of sub-grades and modify the load–displacement behavior of the footing [3] . The investigations also made on the laboratory-model tests for the bearing capacity of a strip foundation supported by a sand layer reinforced with layers of geo-grid [4]. Research on the ultimate bearing capacity of strip and square foundations supported by sand reinforced with geo-grid has also been performed [5]. Das and Omar presented the ultimate bearing capacity of surface strip foundations on geo-grid-reinforced sand and un-reinforced sand [6]. Dash et al. investigated the use of vertical reinforcement along with horizontal reinforcement. The reinforcement consisted of a series of interlocking cells, constructed from polymer geo-grids, which contain and confine the soil within its pockets [7] . Schimizu and Inui carried out load tests on a single six-sided cell of geo-textile wall buried in the subsurface of the soft ground [8]. Mandal and Manjunath used geo-grid and bamboo sticks as vertical reinforcement elements and studied their effect on the bearing capacity of a strip footing [9]. Rajagopal et al have studied the strength of confined sand and the influence of geo-cell confinement on the strength and stiffness behavior of granular soils [10]. Dash et al. performed an experimental study on the bearing capacity of a strip footing supported by a sand bed reinforced with a geo-cell mattress [11]. Study of bearing capacity of footing without reinforcement under eccentric inclined loads by many researchers has been carried out [12-15]. Nearly 340 foundations by adopting Terzaghi method have been calculated and the results presented in form of tables and graphs, the result helps better understanding of improving of soil foundation bearing capacity.