非饱和土抗剪强度及土压力统一解

基于统一强度理论和非饱和土双应力状态变量抗剪强度，合理考虑中间主应力效应，建立了非饱和土双应力状态变量抗剪强度统一解，并与文献试验结果进行比较，验证了公式的正确性；进而考虑基质吸力的不同分布，得到非饱和土主动土压力和被动土压力统一解，克服了朗肯土压力的不足，并得出中间主应力和基质吸力对土压力的影响特性。研究结果表明，主动土压力随着统一强度理论参数和基质吸力的增大而不断减小，被动土压力则相反；当基质吸力沿深度线性减小时，主动土压力和被动土压力都不像基质吸力沿深度为常数时变化得那么快。该结果为非饱和土抗剪强度和土压力分析提供了理论依据，对工程设计有一定的参考价值。

Unified solutions of shear strength and earth pressure for unsaturated soils

Considering the effect of the intermediate principal stress rationally, the unified solution of shear strength for unsaturated soils in terms of two state stress variables is presented, which is based on the unified strength theory and shear strength for unsaturated soils in terms of two state stress variables. Good agreements can be found between the results of this study and some results reported in the literatures. The proposed unified solution of shear strength for unsaturated soils in terms of two state stress variables is validated. With different distributions of matric suction, the unified solutions of active and passive earth pressures for unsaturated soils are deduced, which can avoid the shortages of Rankine earth pressures. The effects of the intermediate principal stress and matric suction on earth pressures are discussed. It is shown that the active earth pressure decreases with increasing the unified strength theory parameter or matric suction, whereas the passive earth pressure inverses. The active and passive earth pressures do not change more quickly when matric suction decreases linearly in deepness than that is constant.