Numerical Analysis Of The Bearing Capacity Of The Foundation Under Cross Strip Load

In practical engineering,it is widely used in the form of strip foundation.For the strip foundation bearing capacity,it is convenient to take it as a plane strain problem.This paper mainly studies the bearing capacity of the foundation under the cross strip load.For the bearing capacity of the cross strip load is a three-dimensional problem,and plane strain analysis can not reflect its failure characteristics.The present study for cross strip foundation is relatively small,resulting in a conservative design of the bearing capacity and a waste of material and bearing capacity,so it is necessary to do some study on its bearing capacity,which is better to guide the actual project.For the load distribution on the surface of the cross strip foundation,this paper assumes that the uniform load is used instead of the concentrated load at the intersection.In this paper,FLAC3 D is used to study the bearing capacity of foundation,and the distribution of stress,and the failure mode and the deformation mechanism under different forms of foundation,and the following main conclusions can be obtained:(1)The bearing capacity of the foundation under the "rectangular" shape load,"matts" shape load and the "nine grids" shape load is increasing with the increase of the internal friction angle.When the internal friction angle is constant,the bearing capacity of the foundation under the "rectangular" shape load,"matts" shape load and "nine grids" shape load is increasing.For the "rectangular" shape load,the foundation uplift is basically equal to the inside and outside of the foundation;for the "matts" shape load and the "nine grids" shape load,when the foundation is destroyed,the foundation uplift of the foundation is larger than the inside.(2)For the "rectangular" shape load,the length to width ratio has some influence on the bearing capacity.In the range of a certain length to width ratio,the bearing capacity of the foundation increases first and then decreases with the increase of length to width ratio.By numerical simulation,the bearing capacity of the foundation is increased by 11.4% at different length to width ratio.(3)When the length to width ratio of the "rectangular" shape load is 1,the bearing capacity of the foundation increases with the decrease of the length of the foundation in a certain range.Through the numerical simulation,the bearing capacity of the foundation is increased by 15.7%.(4)Under the effect of different length to width ratio,the depth of shear strain rate is larger than the depth below the short direction,and the bigger the length to width ratio is,the larger the depth difference is.Due to the interaction between the "rectangular " shape,the outer shear strain rate envelope is extended to the surface of the load,and the inner shear strain envelope does not extend to the surface of the foundation.At the same time,the failure mode of foundation is similar to the wholeshear failure,but the damage curve is no longer symmetrical about the center.When the length to width ratio of the "rectangular" shape load is 1 and the length of side is less than 2m,the bearing capacity of the foundation is greatly influenced by the length of side;When the length of side greater than 3m,The bearing capacity of the foundation is less influenced by the length of side.