放坡条件下有限土体主动土压力计算

Active Earth Pressure Calculation of Limited Soil in Grading Conditions

通过极限平衡法推导了放坡条件下有限土体主动土压力计算公式,基于该公式分析了不改变有限土体宽度与基坑深度的比值(b/H),但改变基坑大小的情况下,对剪切面破裂角无影响,且有限土体主动土压力与基坑深度的平方成正比关系。改变边坡坡角,随着b/H的值增大,剪切破裂角及有限土体主动土压力会趋于一定值,且该计算公式适用范围与边坡坡角无关,与内摩擦成负相关。

Formula of active earth pressure of limited soil under grading conditions is derived by limit equilibrium method. Based on this formula, not changing the ratio of limited soil width and pit depth（b/H）,but changing the size of pit, this study finds out that the rupture angle of shear surface would not be influenced and the active earth pressure of limited soil is in proportion to the square of pit depth. With the change of slope angle, value of b/H increases, shear fracture angle and active earth pressure of limited soil tend tobe a certain value. And scope of this formula is irrelevant to slope angle and negatively correlates with internal friction.