基于弹性半空间理论的土石混填路基压实度确定方法

A Determination Method for Compactness of Soil-rock Mixture Subgrade Based on Elastic Half-space Theory

针对现有路基压实度检测方法用于土石混填路基存在的诸多局限性与不足,提出了一种基于贯入试验的土石混填路基的压实度快速检测方法.首先,利用在受载前后岩土颗粒体积不变的条件,建立了土石混填料孔隙率与变形模量的变化关系.在此基础上,将土石混填路基视为半无限弹性空间,引进分级加载的思想,基于布辛奈斯克解导得了均布荷载条件下的包含初始孔隙率参数的荷载与变形计算公式,再将其转化为压实度与初始孔隙率之间的关系,从而确定压实度.该公式中仅包含两个基本参数,可由曲线拟合求出.最后,利用自行设计的实验装置开展了现场试验,对该方法进行了验证.试验对比数据表明,得到的压实度精度满足工程要求.

Some limitations and insufficiencies are found in the detection methods to check the compactness of filled subgrade,so a new method was put forward.Firstly,in view of the characteristic that the solid（soil and rock） volume does not change in the soil-rock mixture subgrade when it is loaded,a model which can describe the change of porosity in the soil-rock mixture subgrade was established,and the changing regularity of the deformation modulus of soil-rock mixture subgrade was also deduced.Then,the soilrock mixture subgrade was regarded as a semi-infinite elastic space,and the changing regularity of its deformation modulus under the action of load was taken into account,and a method for calculating the deformation or settlement of soil-rock mixture subgrade under the vertical surface load was brought forward on the basis of Boussinesq＇s solution by adopting the idea of step loading.Afterwards,the relationship between the initial porosity ratio of soil-rock mixture subgrade and load-moment curves was established,and the new way to detect the compactness of soil-rock mixture subgrade was set up on the basis of static load test curves.Finally,the site test data show that the results of the new method are close to that of the common one,indicating the feasibility and validity of the new method.