沟埋式矩形涵洞土压力及填土等沉面分析

Study on the Equal Settlement Plane of Filling and Earth Pressure of Trench-buried Culvert

填方工程中,填土在涵洞附近形成土拱,导致现有关于涵洞土压力理论计算值与实测值相差较大。为了探讨涵洞对填方工程变形的相互影响,对沟埋式涵洞顶部土压力及填土变形进行了对比分析,计算结果表明:沟埋式涵洞内土柱的竖向沉降小于外土柱的竖向沉降;沟埋式涵洞顶部土压力系数均大于1,且随沟槽宽度的增大而增大,当沟槽宽度为涵洞宽度10倍时,土压力系数已接近最大值;土压力系数随沟槽深度的增大而呈线性减小规律,当沟槽深度大于涵洞高度的2倍以上时,涵顶土压力可按上覆土重计算;涵洞侧壁受到的剪应力随着沟槽宽度的增加而增加,随着沟槽深度的增加而呈线性减小规律。

For the filling engineering,the soil arch formed by filling near the culvert lead to differences between the calculated value and the measured value of culvert earth pressure.To discuss the mutual influence of culvert on filling engineering deformation,the earth pressure and the filling deformation above the trench-buried culvert are analyzed.The results show that the vertical settlement of the interior soil column of the culvert is less than that of the exterior soil column.The earth pressure coefficient at the top of the culvert exceeds 1.0,increases with the trench width,and almost reaches the maximum when the trench is 10 times wider than the culvert.The coefficient decreases linearly with the increase of trench depth,and the earth pressure above is equal to the overlying soil weight when the trench is 2 times as deep as the culvert height.The shear stress on the side wall of the culvert increases with the trench width,and decreases linearly with the increase of trench depth.