The Ultimate Bearing Capacity of Foundation Based on Unified Strength Theory

The ultimate bearing capacity of foundation based on MohrCoulomb strength criterion does not take effect of intermediate principal stress on yield and failure of soil into account,so that the disparity between results obtained with MohrCoulomb strength criterion and those from experimental data are produced .In the paper, the ultimate bearing capacity of foundation based on unified strength theory is established and an unified solution is obtained. The corresponding solutions of different materials can be got from it. Formulae are derived with the influence of soils cohesive strength,overburden loads on sides of foundation and the self weight of soils. Taking strip foundation as an example ,the influence of intermediate principal stress and properties of the materials with different tensionpressure strength on the ultimate bearing capacity of foundation are calculated. The unified solution can not only be used to fit the properties of the materials with different tensionpressure strength but also those with equal tensionpressure strength.The results show that the properties of materials and intermediate principal stress importantly affect the ultimate bearing capacity of foundation.