各向异性砂土主动侧土压力计算方法

Evaluation of earth pressure at active side for anisotropic sand

土压力是土力学和岩土工程领域的基本研究课题之一。由于碾压作用墙后填土具有不同程度的各向异性,并且通常处于主动与被动状态之间的非极限状态。经典的朗肯和库仑土压力理论没有考虑填土各向异性的力学性质及挡墙位移效应对于土压力的影响。基于各向异性砂土的等应变增量比系列试验结果建立了土压力系数与与用应变增量比表述的应变约束条件之间所具有的惟一性关系,在此基础上给出了平动位移模式下各向异性砂土的主动土压力计算方法,并通过土压力离心模型试验结果对其计算方法进行了验证,初步表明了其有效性和合理性。

Evaluation of earth pressure is one of the key research subjects in soil mechanics and geotechnical engineering. The backfill displays anisotropic mechanical characteristics because of compaction in engineering practice; it is always at the non-limit state between the active and passive states. Classic Rankine and Coulomb earth pressure theories do not consider the effect of anisotropy and backfill deformation on the earth pressure. Based on a series of constant strain increment ratio tests, the unique relation between the earth pressure coefficient and the lateral strain constraint is established for anisotropic sand. On this basis, a method is proposed for estimating the earth pressure at the active side for anisotropic backfill sand under translational wall movement mode; and corresponding formulas are derived. Besides, the effectiveness of the suggested method is confirmed experimentally.