基于散体材料性质的土石混填路基压实度快速检测方法

A method for rapid measuring the compactness of soil-rock mixed subgrade based on the characteristics of granular material

基于静力贯入试验检测土石混填路基压实度是目前实现压实度快速检测的有效方法,但其检测原理有待深入研究,因此,首先基于现有散体材料应力传递机制的研究,假设应力在路基土石混合料中以曲线圆锥的形式向下扩散传递,建立适合土石混填路基散体材料的应力分析方法,其次,基于孔隙介质力学理论,建立变形模量、泊松比及孔隙率随路基变形而变化的规律,并引入分层总和法及分级加载思想,建立土石混填路基荷载–沉降分析模型即P-s解析关系,然后,结合路基静力贯入试验测得的P-s试验曲线,利用自适应模拟退火优化方法反演获得路基初始孔隙率,从而建立基于散体材料性质的土石混填路基压实度快速检测方法,该方法避免了繁琐的标定试验,且检测精度可满足工程要求,最后,通过现场实测结果以及本文与现有方法分析结果的比较分析,表明了提出方法的合理性与可行性。

Static penetration experiments is an effective method for rapid measuring the compactness of soil-rock mixed subgrade. However, the testing principle need to be further studied. In this paper, a method of stress analysis suitable for the granular material of soil-rock mixed subgrade is established by assuming the stresses transmitted downward with the shape of cone in the soil-rock mixture based on the stress transmission mechanism of granular material. The deformation modulus, Poisson＇s ratio and porosity varied with the deformation of subgrade is determined on the basis of the porous media mechanics. A force-settlement relationship of soil-rock mixed subgrade, i.e. the P-s curve, is established based on the layer summation method. On the basis of the P-s curves obtained with the static penetration experiments, the initial porosity is obtained with the method of back analysis using an adaptive algorithm. The method for rapid measuring the compactness of soil-rock mixed subgrade is thus established. The accuracy of this method meets the engineering requirement without the complicated calibration experiments. The results of proposed method were compared with the results from tests and existing method and proved that this method was reasonable and feasible.