Water And Earth Pressures Acting On Retaining Structure And How To Choose The Shear Strength Parameters

Water and earth pressures are important forces on the supporting structure around a foundation pit. But there are different views in geotechnique field about estimating the water and earth pressures. The problems are put forward under the condition. The research involves two problems how to estimate the water and earth pressures on the supporting structure around a foundation pit and choose the strength parameters.The paper analyses the shear strength parameters for the unconsolidated-undrained triaxial test and the consolidated-undrained triaxial test in layered soil. At the same time, based on the theory of Rankine's earth pressure, several kinds of reasonable formulae about water and earth pressures are put forward. Combined several practical foundation pit engineerings these equations are calculated according to the shear strength parameters of UU and CU test. At last, the results are tested and verified.The results are as followed. The several ways are almost equal to each other when earth pressures are calculated by the shear strength parameters of UU and in this condition the influences from water-soil calculating separately and together are negligible. When earth pressures are calculated by the shear strength parameters of CU, the way water-soil calculating separately is best, which should involve the influences of excess pore water pressure through the total stress unloading strength parameters of CU. Although the results of the earth pressure are not equal, the differences are very small. So different ways are advised in accordance with specific foundation engineering.