减荷拱涵周围土体位移变化的离心模型试验

通过土工离心模型试验,利用拱涵模型模拟了实际路堤的回填材料、沟坡地形、减荷材料、地基形式及施工工艺,并使用图片测量软件分析了拱涵周围土体在未减荷与EPS板减荷工况下的变形运动性状和全局位移场的差异。根据试验结果再现了两种试验工况下,拱涵周围土体随填土高度增加的运动变化过程;模拟了EPS板变形作用下涵顶土拱的形成和基本形态;分析了拱效应影响下的拱涵基底土体的运动情况,发现通过卸荷拱转嫁到拱涵两侧土体的荷载促使基底两侧土体向基底中心运动,从而对基底产生了向上的反力,减小或阻止了拱涵自身的沉降。结果表明:合理模量和厚度的EPS板既可以减荷,也可以起到稳定结构纵向不均匀沉降的作用。

Centrifugal Model Test on Displacement Variation of Earth Surrounding Reducing-Load Arch Culvert

Based on civil centrifugal model test,using arch culvert model,filling material,trench terrain,reducing-load material,form of foundation and construction technics were simulated.Using picture measurement software,the deformation movement characteristic of earth surrounding EPS plank reducing-load and reducing-unload arch culvert case and the difference on the overall displacement were analyzed.According to experimental result,movement variation process of earth surrounding culvert vs increase of fill height under two experimental cases was displayed;soil arch form at the top of culvert and basic shape under the action of EPS plank deformation were simulated;the movement situation of the fill under the bottom of the foundation with the arching effect was analyzed and discovered that the load which shifted from unload arching to two sides of earth surrounding arch culvert made two sides soil at the bottom of foundation move to center at the bottom of foundation so that counter-force at the bottom of foundation was produced,self-settlement of arch culvert decreased or obstructed.The result shows that EPS plank with reasonable modulus and depth can not only reduce the load,but also play a role in stabilizing and balancing the longitudinal unequal settlement.