Experimengt Study Of The Bearing Capacity Of Foundation Soil Under Inclined Loads

In civil engineering, foundation soil not only bears the long-term effects of the vertical gravity load, but also the role of wind load and so on. These loads reach to the foundation through the basis of structure, making the foundation under the combined action of vertical load and horizontal load. By model test, field test and numerical simulation, this paper analyzes and researches the failure mode of foundation under inclined load and the influence factors of its ultimate bearing capacity. The main research contents and results are as follows:1. Doing research on indoor model test, and the results shows that:under inclined load, when the inclined angle is uniform, the results calculated by Hansen formula and Vesic formula have bigger error with test results, so the value calculated by theoretical formula can not accurately reflect ultimate bearing capacity of foundation under inclined load. At the same time, with the increase of angle, ultimate bearing capacity decreases gradually, and the decreasing rate increases gradually.2.Combined with field test, when vertical load is consistent, comparing the size of horizontal load measured with the size of horizontal load calculated by relevant specification formula. Results show that:the relative error calculated by the consolidated quick shear strength index is bigger than the relative errors calculated by filed plate test and triaxial test(CU), so we should choose the reasonable strength index in the design process.3. The three-dimensional numerical simulation analysis was carried out on field test, using the equivalent plastic strain nephogram to determine the failure mode of soil. Under inclined load, foundation failure modes can be divided into two kinds, one is the sliding surface damage, and the other one is the deep sliding failure. And the critical load of homogeneous soil’s two failure models is about0.5Vu.4. Using the three-dimensional numerical simulation study the sensitivity, such as the friction coefficient between basis bottom and foundation, the width of basis and the depth of basis. Results show that:①When vertical load is uniform, the horizontal bearing capacity of foundation can be increased by increasing roughness between basal and contact surface, increasing foundation width, increasing the embedded depth of foundation, and so on.②When the load must be one value, we can increase roughness between basal and contact surface and foundation width to decrease the uneven settlement of foundation. With the increase of embedded depth, foundation settlement decreases, but trend of uneven settlement does not slow down.③When the load must be one value, we can increase roughness between basal and contact surface, foundation width and embedded depth of foundation to reduce the horizontal displacement of the foundation.