吸力等效膨胀力在非饱和膨胀土边坡稳定性中的宏观作用评价

Evaluation of macroscopic function of suction-equivalent expansive force in stability of unsaturated expansive soil slope

非饱和膨胀土边坡的失稳问题是岩土工程中迫切需要解决的工程难题之一.对吸力等效膨胀力和基质吸力进行测试分析和比较;通过考虑基质吸力非均匀分布和等效膨胀力非均匀分布条件下的南阳非饱和膨胀土边坡稳定性计算,分别探讨3种计算方法的差异,并对计算结果进行对比.研究结果表明,通过吸力等效膨胀力可以反映非饱和膨胀土的基质吸力的宏观贡献;研制的膨胀力测试装置使膨胀力试验的精度大大提高,还大大缩短了膨胀力试验的测试时间;基于卢肇钧提出的非饱和土理论公式的强度折减有限元分析方法具有较大的优越性.

The collapse of unsaturated expansive soil slope is one of the difficult engineering problems that need to be urgently solved in geotechnical engineering. The test analysis and comparison of suction equiva lent expansive force and matrical suction were carried out. By means of stability evaluation ofNanyang un saturated expansive soil slope under condition of considering the inhomogeneous distribution of matrical suction and suction equivalent expansive force, the differences of three kinds of stability evaluation meth ods were respectively explored, and the calculation results were compared. The research results show that suction equivalent expansive force can be employed to reflect the macroscopic contribution of matrical suc tion to unsaturated expansive soil. In addition, the developed test device of suction equivalent expansive force will greatly improve the test precision of expansive force and shorten its test time. The strength re duction finite element method based on Lu Zhaojun-s unsaturated soil strength formula will have a greater advantage.