低填方上埋式管涵土压力的模型试验和理论研究

Model tests and theoretical studies on earth pressure on shallow positive buried culverts

针对无黏性填土,通过模型试验和理论分析研究了低填方上埋式刚性管涵周围的土压力分布特性。基于试验结果和修正的马斯顿理论提出了较为合理的管涵土压力计算模型和计算公式,并根据试验数据确定了计算模型中的关键参数,通过不同埋深的试验工况结果对比表明:该计算模型能较好地反映实际的管涵周围土压力分布模式,在浅埋条件下管顶中心位置处土压力集中现象随管顶填高的增大而渐趋明显。同时,当填高较小时,管土界面法向土压力随分布角度θ增大先增后减;而填高较大时,管土界面法向土压力随分布角度θ增大而增大。

The distribution of earth pressure over a positive rigid culvert buried in non-cohesive soil is studied by means of model tests and theoretical analyses.Based on the measured results from the full-scale physical model tests and the Marston’s theory,a more reasonable analytical model of earth pressure over the culvert is proposed,and the principal parameters are determined based on the test data.The test results with various buried depths on culvert top show that the proposed model can describe the earth pressure distribution over the culvert effectively.The concentration phenomenon of earth pressure on top of the stiff culvert becomes more significant as buried height increases.The normal earth pressure between the soil and the culvert increases first and decreases afterwards with the distribution angle θ for lower embankment height,whereas it increases monotonically with the distribution angle θ for high embankment height.