碎石层缓冲差异沉降模拟试验研究

为研究碎石层对差异沉降的缓冲性能,设计了模拟差异沉降试验箱,通过模拟试验验证了碎石层缓冲差异沉降的效果;在碎石层缓冲差异沉降机理分析的基础上,提出了二次松散系数的概念及计算公式,设计了碎石层二次松散系数测试箱,并分析了粒径大小、颗粒形状、内摩擦角与二次松散系数的关系。根据常见的沉降曲线形状推导了相应的碎石松散边界方程,并由此分析了影响碎石松散区域大小的主要因素。研究表明:碎石模拟试验箱的设计及试验是成功的;碎石层散体材料可以缓冲差异沉降主要是由于其具有二次松散的性能;二次松散系数随碎石粒径及内摩擦角增大而增大,且同粒径卵石的二次松散系数总是低于碎石;沉降最大值及二次松散系数是决定松散区域厚度的主要因素。

Study on Model Experiment of Differential Settlement Elimination of Crushed Rock Layer

In order to research the capability of eliminating differential settlement of crushed rock layer,model experiment box was designed.Through the model experiment,the effect of differential settlement elimination was validated.Then the concept and the expressions of secondary relax coefficient was established.Through measuring different rock layer's secondary relax coefficients by designed measure box,the relationships of grain diameter of crushed rock,grain figure of gravel,inner friction angle with the secondary relax coefficient were analyzed respectively.On the basis of the familiar settlement curve,the relax boundary equation was established and the influence factor of relax area was discussed.The research indicates that(1) the design of model experiment box and th experiment are successful;(2) crushed rock layer which can eliminate differential settlement mostly owing to its capability of secondary relax;(3) the coefficient of secondary relax increases with grain diameter of crushed rock and the friction angle,and the secondary relax coefficient of crushed rock always higher than that of the scree with same grain diameter;(4) the maximum of differential settlement and secondary relax coefficient are the primary influence factors to relax thickness.