Analysis of strip footings resting on reinforced granular trench by the finite element method

Abstract

<p>Numerous methods have been used in the past and recent time to enhance the bearing capacity of the soils, depending on the type of the structure, available equipments, and the properties of the soil. The use of granular trench (two-dimensional plane strain condition of stone column) is one of these methods. This paper provides a finite element method to model soft cohesive soil, granular trench soil, and the reinforcement material by using a computer program called (SIGMA/W). The behavior of both cohesive and granular soils is simulated by nonlinear-elastic soil model (hyperbolic model), while the linear-elastic model was used to simulate the reinforcement material.</p><p>The angle of friction of trench soil, modulus of elasticity of reinforcement material, depth, width and shape of the granular trench, locations, and number of the reinforcement layers were varied. The sloped granular trench was analyzed in two cases; lined and unlined conditions. The results showed that use of granular trench beneath foundations will increase the bearing capacity and reduce the settlement. Moreover, using of polymers as a reinforcement material has a significant effect on both bearing capacity and settlement.</p><p>For both reinforced and unreinforced granular trenches, the depth ratio has an important effect on the settlement ratio, which decreases with the increase of depth ratio. The best practical value for the depth ratio was found to be equal to 2. Making a trench with a width (<i>X</i>) larger than the foundation width (<i>B</i>) also decreases the settlement, and the best effect occurs when the width ratio (<i>X/B</i>) equals to 0.75.</p>