倾斜填土面朗肯土压力的计算及其强度分布规律

Calculation and strength distribution of Rankine earth pressure on inclined surface

根据倾斜填土面时土体中一点的应力状态分析,采用应力圆图解法推导出倾斜填土面粘性土的朗肯主动和被动土压力强度的计算公式,把该公式视为关于填土深度z的线性关系方程和非线性关系方程两部分。通过对该公式的非线性方程部分分析可知,朗肯主动与被动土压力强度分布形态与填土面倾角β和内摩擦角φ两者的大小有关,因此分β>φ、β=φ和β<φ三种情况对朗肯主动与被动土压力强度分布形式进行了讨论,并绘制了土压力强度的分布图形,其分布图形具有非线性特点。其中在β<φ的情况下,主动土压力强度在一定深度z2以下范围出现无解现象。最后将推导公式应用到某挡土墙实例中,对比分析表明,该理论结果与现场实测结果具有较好的一致性。

According to stress state of one point on an inclined surface,we derived the formula of Rankine active and passive earth pressure on inclined surface by means of graphic method of Mohr Circle.The formula can be seen as two parts in the linear equation and non-linear equation of the filling depth z.By analyzing the part of nonlinear equation,we find that strength distribution of Rankine active and passive earth pressure on inclined surface is related to the relationship between internal friction angle φ and angle of inclined surface β.We obtain the forms of strength distribution of Rankine active and passive earth pressure on inclined surface and draw the graphics of distribution of earth pressure strength with 3 situations β φ,β = φ and β φ.The graphics of distribution is nonlinear.Rankine active earth pressure does not have solution in the case of β φ below certain depth z2.Finally,the presented formulas are applied in practical engineering.The experimental results in this instance can be well described by the presented formulas.The presented formulas are proven to be effective.