相邻基坑有限宽度土条主动土压力的计算

同步开挖的相邻基坑间有限宽度土条不同于以往的邻近既有建筑基坑的有限土条，其破坏方向未知，破坏形式多样，土条两侧的主动土压力计算不能沿用以往的研究成果来扩展应用。借鉴筒仓受力原理应用于相邻基坑间的土条分析计算，通过力学平衡分析和微分方程求解，得出基坑开挖中两侧均为支护结构的有限宽度土条（砂土和黏性土）的主动土压力计算公式，该公式输入参数少、假设条件少，使用方便。对比朗肯主动土压力计算公式和有限元数值模拟计算结果，该计算公式与有限元模拟计算结果基本一致，在相同深度处计算的土压力远小于朗肯土压力。

A method for calculating active earth pressure of soil piece with a finite width between adjacent foundation pits

The soil piece with finite width between the adjacent foundation pits in synchronous excavation is different from the one adjacent to existing building foundation pit. Their destruction direction is unknown, the destruction forms are various. Therefore it is difficult to apply the existing methods to calculate the active earth pressure on both sides of the soil piece. The silo balance principle is intruduced. By the mechanical equilibrium analysis and solving differential equation, a formula is developed for calculating the active earth pressure on the supporting structure installed on both the sides of soil piece (sand and clay) with a finite width. The formula has fewer parameters, less conditions and is convenient to use. By comparing with results from the Rankine active earth pressure calculation formula and the finite element simulation, it is found that the results by proposed procedure are consistent with those by Rankine’s method and finite element simulation. But the earth pressure by this paper is far less than Rankine earth pressure at the same depth.