基于孔隙介质理论的路基压实度确定方法

为克服以往路基压实度快速检测法中需要繁琐的标定试验及忽视初始地应力对变形参数影响的缺陷,建立了路基压实度快速检测新方法.首先,基于孔隙介质理论,研究了孔隙率、变形模量及密度随路基材料变形而变化的规律;其次,引入分层总和法和分级加载思想,考虑初始地应力和路基变形均影响路基力学参数变化的特征,建立静力贯入条件下贯入荷载-沉降解析关系;然后,在路基静力贯入试验测得荷载-沉降试验曲线的基础上,利用自适应遗传退火算法反演得路基贯入荷载-沉降解析关系中的各参数,从而建立基于孔隙介质理论的路基压实度确定方法;最后,通过工程实例对比可知,本文方法精确度满足工程要求,检测过程中无需繁琐的灌水法标定试验,能快速准确地检测路基压实度,表明了本文方法的合理性和可行性.

Determination Method of Subgrade Compactness Based on Porous Media Theory

In order to overcome two faults of the complicated calibration experiment in present methods for quick testing subgrade compactness and the neglectful effect of initial ground stress on deformation parameters, a new method for quick testing subgrade compactness was established. Firstly, the laws of porosity, deformation modulus and density varying with the deformation of subgrade soils were studied based on porous media theory. Then, the force-settlement analytical relation was established by considering the effect of initial ground stress and subgrade deformation on variational mechanical parameters by using the layer-wise summation method and step-loading idea in the process of static penetration. Besides, on the basis of force-settlement curves observed by static penetration experiments, the parameters of force-settlement analytical relation were obtained by back-analyses with adaptive genetic annealing algorithm, and the determination method for subgrade compactness based on porous media theory was then established. Finally, the engineering cases proved that the accuracy of this method satisfied the engineering requirements, and this method tested the subgrade compactness quickly and accurately without complicated calibration experiments which are essential in present methods. It shows that the proposed method is reasonable and feasible.