At the same time, the author also assumes the opposite direction of the bottom sliding surface dip as the direction of the shear stress on it ,so as to make the vague direction specified.

• 同时,本文还将计算模型中所需用到的底滑面剪力方向假定为了与其倾向相反,使这个一直比较模糊的方向得到了具体化。