基于静力贯入的土石混填路基压实度确定方法

Determination Method for Compactness of Soil-rock Mixture Subgrade Based on Static Penetration

为了建立土石混填路基压实度确定新方法,在研究土石混填路基静力贯入变形力学机理的基础上,将贯入变形视为贯入形成的土石柱压缩变形及柱端沉降两部分,考虑到土石柱及柱端土石体被压缩导致其孔隙率和变形模量变化的特点,引进分级加载的思想,分别提出土石柱压缩变形及柱端沉降的计算方法,从而建立贯入变形与路基初始孔隙率的分析模型;依据静力贯入试验曲线,采用基于自适应的遗传模拟退火优化算法,建立初始孔隙率的反演分析方法;根据初始孔隙率与压实度的关系确定路基压实度,进而建立基于静力贯入的土石混填路基压实度新型确定方法;最后,通过工程实例分析了该方法的合理性与可行性。结果表明:该方法不仅可以确定土石混填路基压实度,而且可确定其他力学参数。

In order to set up a new determination method for compactness of soil-rock mixture subgrade,based on the discussion of the mechanical deformation mechanism of soil-rock mixture subgrade under static penetration,the deformation of the subgrade was regarded as the compression deformation of the soil-rock column and the settlement of its column end.Meanwhile,considering the variational characteristics of the porosity ratio and deformation modulus when the soil-rock column and the soil-rock mass of the column end were compressed under static penetration,a method of calculating the deformation of the soil-rock column and the column end was set up by introducing the idea of step loading,thereby,analysis model about the static penetration deformation and the initial porosity ratio of subgrade was established.According to the static penetration test curves,a method of back analysis about its initial porosity ratio was developed by use of adaptive genetic simulated-annealing algorithm.Then,the compactness of soil-rock mixture subgrade was determined by the relationship between the initial porosity ratio and the compactness.Consequently,a method of determining the compactness of soil-rock mixture subgrade based on static penetration was set up.Finally,feasibility and rationality of the method were analyzed through practical engineering.Results show that the method can determine not only the compactness but also the other mechanical parameters.