分析非饱和膨胀土的强度特性，考虑非饱和膨胀土含水量与强度的关系及相关影响因素,基于平面滑裂面假设，运用库仑理论，推得了计算非饱和膨胀土主动土压力的解析解公式，并用实际算例对公式进行检验。算例分析表明，随着含水量的增加，主动土压力增大，其变化幅度逐渐减小；若不考虑含水量的影响，结果偏于保守；应用本文建立的解析解公式，可直接得出膨胀土的主动土压力及填土滑裂面与水平面的夹角。

The strength characteristics of unsaturated expansive soil was analyzed，based on the plane sliding surface assumption, the analytical formula of the active earth pressure calculation for unsaturated expansive soil was proposed which considered the relationship between water content and strength of unsaturated expansive soil and other relevant factors, using the basic principle of Coulomb theory, and practical example was used to validate the formula. The example showed that the active earth pressure increased with the increase of moisture , while the magnitude of the change decreased; If the influence of water content was not considered, the result was conservative; The active earth pressure of expansive soil and the angle of filling sliding surface with the horizontal could be obtained directly applying the method established in this study.

安徽高等学校省级自然科学研究重点项目（KJ2011Z320）;合肥学院土木工程重点学科建设项目(2014xk04)