عنوان مقاله [English]
The settlement of a soil layer beneath structures has an important role in the designing procedure. Consolidation is a major mechanism of settlement in the cohesive soils. In some area, sand lenses may be existed in soil layers which facilitate the dissipation of the excess of the pore water pressure. Since they may possess any arbitrary shapes, the numerical simulation of the phenomena, may face with some difficulties in domain discretization when a conventional mesh based method are used. Meshfree methods are rather new approaches in the numerical solution of the engineering problems which gives a flexible tool in the discretization of domains with complex geometry. In this paper a least squares based and integral free meshless method, named Collocated Discrete Least Squares (CDLS), is used to solve two dimensional consolidation problems in the present of sand lenses with different kinds of shapes and positions in a cohesive soil. In this paper, a bench mark problem is solved to validate the
proposed scheme. Then more complicated problems are dealt with to investigate the effect of existence of sand lenses and the location of them into the settlement process of the cohesive soils. Also the results show the proposed approach, can obtain reliable solution for even complicated problems. It is shown that sand lenses have considerable effect in the settlement a soil depending on its shape and orientation. It can be predictable since the excess pore water pressure dissipates from all lateral surfaces of the sand lenses and the external loading will put on the soil aggregate sooner. In type of orientation for the sand lenses, the pore water pressure dissipates more slowly than the lenses with a plane look. The results show that the effect of sand lenses can be more noticeable if they have a plane and horizontal shapes.