Analysis of the Bearing Capacity of Red Clay Foundation Considering Stress Level

Abstract

Accurately evaluated the bearing capacity characteristic value of red clay is of great important to make use of high strength. Based on analyzing current specifications methods to determine the bearing capacity eigenvalue of red clay foundation, it is found that deficiencies are the limitation of application, the disturbance of determining indexes such as water content, liquid limit, plastic limit and compression modulus, and even lack of reflecting effects of the stress level, the shape and failure mode of subgrade. To deal with these shortcomings, a method for determining the bearing capacity of red clay foundation in view of the stress level was proposed. This method adopts tangent modulus that can reflect different depth of stress levels instead of compression modulus to calculate the curve of load and settlement under the size of plate, and utilizes the modified Vesic formula to consider the influence of the shape and failure mode of ground to calculate the ultimate bearing capacity as major parameter of different depth of stress level calculation. The indoor shear strength index can be used to calculate the ultimate bearing capacity if there is no plate load test. According to the characteristic of the settlement and load curve, the intrinsic value of subgrade bearing capacity is achieved using the plate load test method. Verified through an engineering cases, the characteristic value of the bearing capacity obtained using this method is more consistent with that obtained by the plate load test, meanwhile more flexible in the actual application. It also can be used for reference to determine the characteristic value of bearing capacity in other red clay area.