Study On Active Earth Pressure On Retaining Wallbased On Soil Arch Effect And Shear Stress

Earth pressure on retaining wall is an important issue in the field of soil mechanic. The classical Rankine and Coulomb earth pressure theory shows that earth pressure is distributed nonlinearly along the depth of retaining wall, which is not corresponded with the test results in the field or in the lab. Therefore, it is necessary to describe earth pressure on retaining wall accurately, which is also meaningful.The existing theory shows that soil arch effect is the key reason to lead to the nonlinear distribution of earth pressure. Many researches focus on the sand filling in the mood of translation, and few on the multilayer filling and limited filling. Otherwise, lots of researches don’t consider the shear stress between soil layers. In fact, the shear stress between soil layers must be existed and should not ignored according to shear stress mutual equal theory. Given more reasonable assumption and based on soil arch effect, this paper researches the earth pressure on retaining wall more deeply. Following is the main job and conclusion.(1) Based on soil arch effect and considering shear stress between soil layers, the earth pressure of semi-infinite single filling on retaining wall is researched. Compared with other theory, it is found that Coulomb’s slip-surface is more reasonable. Soil arch almost has no influence on the earth pressure, resultant force and position of loading point. Slip-surface is related closely to the earth pressure, resultant force and position of loading point. Coefficient of lateral active earth pressure has no connection with soil arch and slip-surface, which is affected mostly by the internal friction angle of filling and friction angle between retaining wall and filling.(2) Based on soil arch effect and considering shear stress between soil layers, the earth pressure of multilayer filling on retaining wall is studied. Compared with existing theory, it is obtained that Soil arch effect has no influence on the angle of slip-surface and resultant force of earth pressure. The Soil arch effect and shear stress have an impact on the distribution of earth pressure, which bring about the upper earth pressure is less than others’ and the lower of it is more than others’, and then makes the position of loading point lower than others’, but still higher than Coulomb’s.(3) Based on soil arch effect and considering shear stress between soil layers, the earth pressure of limited filling on retaining wall is researched. Compared with existing theory, it is shown that Coulomb’s slip-surface is more reasonable than Rankine’s. Friction angle between retaining wall and filling and distance between retaining wall and rock face are the main factor to affect earth pressure. On some condition, resultant force of earth pressure calculated by the method of limited filling is larger than Coulomb’s, which means Coulomb’s is not safe.Key Words: earth pressure, retaining wall, soil arch effect, shear stress,...