考虑变位影响的刚性挡墙非极限土压力研究

 经典土压力理论仅能计算平移模式挡墙的极限状态土压力。采用以主应力差表示的应力圆，根据应力路径三轴试验中得到的径向应力–应变关系，建立非极限状态下受位移影响的土体内摩擦角、墙土间摩擦角发挥值随位移的变化关系，并提出有效位移面积比方法将该关系量化至转动变位模式挡墙。在此基础上，应用水平层分析法和改进的库仑公式，推导出考虑挡墙变位影响的非极限土压力合力及其作用点位置、土压力分布计算式。研究表明：按有效位移面积比方法进行量化后，理论计算值与实测值相对误差较小；所提出的公式较好地反映了土压力随位移的变化规律，能够分析不同变位模式下的非极限土压力，可作为库仑理论公式的有效推广。

NON-LIMIT STATE EARTH PRESSURE AGAINST RETAINING WALL CONSIDERING INFLUENCE OF DEFORMATION

The classic theory of earth pressure can only be used to calculate the limit earth pressure on the retaining wall under the mode of translation. With the Mohr circle expressed with the principal stress difference and on the basis of the radial stress-strain relation obtained from the stress path triaxial tests，the nonlinear relationships of the mobilized internal friction angle of the soil and the friction angle between the wall and the backfill soils vesus the displacement were established under non-limit state. The method of effective area ratio of wall displacement was put forward to quantify the relationship to rigid retaining wall under the deformation mode of rotation. Based on the method above and combined with the method of horizontal slices and the modified Coulumb?s formula，the formula of earth pressure distribution，the resultant force and its application point under non-limit state which considered the influence of wall deformation were deduced. The result of an example showed that the difference between the theoretical calculation value quantified by the method of effective area ratio of displacement and the measured value was small. The proposed formula well reflects the change of earth pressure with the wall displacement and is an effective extension of Coulumb?s theoretical formula.