加筋路堤下涵洞土压力分布规律及计算方法

基于缩尺模拟试验, 通过改变涵洞两侧地基压缩模量用于模拟堤-涵差异沉降, 揭示涵顶加筋作用机理, 确定路堤堆载条件下涵顶土压力分布规律, 并推导建立土压力计算公式。研究结果表明: 同等地基模量条件下, 加筋路堤下的涵顶土压力明显高于普通路堤, 且随格栅层数增加, 堤-涵相对位移减少; 同等加筋条件下, 地基压缩模量越小, 堤-涵相对位移及涵顶土压力均越大; 综合土拱效应与加筋作用机理, 建立加筋路堤下涵顶土压力计算公式, 并与模型试验结果进行可靠性验证。研究结果可为加筋路堤下涵洞结构设计提供依据。

Distribution law and calculation method of earth pressure in culvert under reinforced embankment

Based on the scale model test, the difference settlement between the embankment and the culvert was simulated by changing the foundation compression modulus on both sides of the culvert to reveal the mechanism of reinforcement and subsidence reduction on the culvert roof, determine the distribution law of earth pressure on the culvert roof under the condition of embankment overloading, and deduce and establish the calculation formula of earth pressure.The results showed that the soil pressure at the top of the reinforced embankment was obviously higher than that of the ordinary embankment under the same foundation modulus. The embankment-culvert relative displacement decreased with the increase of the number of grid layers.Under the same reinforcement condition, the smaller the foundation compression modulus was, the higher the embankment-culvert relative displacement and the soil pressure on the culvert top would be.Combined with the soil arching effect and the mechanism of reinforcement and subsidence reduction, the calculation formula of earth pressure under the roof of reinforced embankment was established, and the reliability was verified with the model test results.