花岗岩残积土路用性能影响因素研究

为了分析花岗岩残积土路用特性，从影响因素入手研究。取湖南境内花岗岩残积土进行室内试验，通过薄片和XRD试验，得到残积土矿物成分及基本结构，发现云母含量较高且呈叠片状结构；通过大量统计与试验，从粒径组成、击实功、含水率三个因素出发，研究残积土路用特性变化。结果表明:细砂对残积土含水性影响关键，粗粒含量与CBR强度呈指数关系，特定粒径组成对残积土路用特性有利；以黏土质砂为试验对象，击实功增加，最大干密度增速“两头大、中间小”，最优含水率降速“两头小、中间大”，最大CBR值先线性增加后基本不受影响；结合击实功进行分析，含水率存在wcr，小于wcr，击实功与CBR正相关，反之负相关。

A study of influence factors on the road characteristics of granite residual soil

In order to analyze the road characteristics of granite residual soil, the influence factors are examined and granite residual soils in Hunan are collected for laboratory tests. Through thin section and XRD experiments, mineral composition and basic structures of granite residual soil are obtained and the results indicates that this kind of granite residual soil has a high content of mica that behaves a laminated structure. Based on a large number of statistics and experiments, this paper studies the change in the road characteristics of the residual soil from three factors, including the particle size composition, compaction energy and water content. The results reveal that the fine sand content is the key influence factor on the soil water-bearing property and the coarse grain content has an exponential relation with CBR. Moreover, the particular particle size composition makes good sense to the road characteristics of granite residual soil. With the rising compaction energy, the head and the tail growth (decent) rate of the maximum dry density are large and the middle is small, contrary to the optimum moisture content. The max CBR value increases linearly and then basically remains unchanged as the compaction energy rises. Combined with the compaction energy, water content has a critical value and is less than this value. CBR is positively correlated with the compaction energy and if not, CBR is negatively correlated with the compaction energy.