高填方涵洞加筋减载的数值模拟

Numerical Simulation on Load Reduction by Reinforcement Bridge of Culvert Beneath High Filling

为确定高填方涵洞加筋减载效果的影响因素及影响规律,在介绍加筋桥减载法及其减载机理的基础上,通过对加筋减载的高填方涵洞的数值模拟,研究了不同格栅层数、减载孔不同宽度、高度和侧壁角度以及减载孔不同填料性质时高填方涵洞的土压力变化规律,分析了高填方涵洞加筋减载的效果。结果表明:减载孔高度和减载孔填料模量对减载效果有较大的影响,减载孔高度越高,减载孔填料模量越低,减载效果越显著;减载孔宽度、格栅层数和减载孔填料的内摩擦角对减载效果影响较小,但减载孔宽度的增加使涵洞受力更均匀,有利于减小结构物内力。

In the aim of identifying the influencing factors and their effects on load reduction effect for culvert beneath high fill,the method and mechanism of load reduction by reinforcement bridge are introduced firstly. On this basis,by means of numerical simulation,the influences of number of geogrid layer,width,height and lateral slope angle of load reduction ditches,as well as properties of filling material on the vertical earth pressure and the load reduction effect are investigated. Results suggest that the modulus of the filling material in the load reduction ditch and the height of the ditch have great effect on the load reduction. Ditches of larger height and lower material modulus lead to significantly better load reduction effect and less vertical earth pressures on the crown of culverts. The width of load reduction ditch,number of geogrid layer and internal friction angle of backfill material have little effect on the load reduction,but the increase of the width of the load reduction ditch results in more uniform internal forces for the culvert and a decrease of bending moment.