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为了探究湘南红黏土公路路基压实标准降低的依据和具体幅度,对红黏土开展了一系列室内土工试验,分析了压实度、含水率对红黏土物理力学特性的影响,获取了渗透率、压实系数、CBR等指标与压实度的关系曲线,最终根据上述指标随压实度的变化规律给出了压实度降低的建议值。研究表明:压实度对红黏土收缩性和膨胀性的影响较小,随着压实度的提高,红黏土的渗透系数和压缩系数均明显降低,而内摩擦角和黏聚力则逐渐增加,但黏聚力在压实度由93%增加到96%过程中没有明显变化,当初始含水率控制在30%左右,压实度大于93%时,红黏土的CBR值均符合规范要求。综合各指标的变化规律,建议湘南地区红黏土路基的压实度可总体降低至93%,且填筑时的含水率应略大于最优含水率。
In order to explore the basis and specific scope of the subgrade compaction standard of southern Hunan red clay highway, a series of indoor soil tests were conducted on the red clay. The influence of compaction degree and moisture content on the physical and mechanical properties of the red clay was analyzed. The permeability, Compaction coefficient, CBR and other indicators of the relationship with the degree of compaction curve, and finally according to the above index with the compaction degree of change gives the compaction of the proposed value. The results show that the degree of compaction has little effect on the shrinkage and expansibility of red clay. With the increase of compaction degree, the permeability and compressibility of red clay decrease obviously, but the internal friction angle and cohesion increase , But the cohesion did not change obviously when the degree of compaction increased from 93% to 96%. When the initial moisture content was controlled at about 30% and the degree of compaction was more than 93%, the CBR values of red clay all met the specification requirements. According to the variation of each index, it is suggested that the degree of compaction of red clay subgrade can be reduced to 93% as a whole, and the water content of filling should be slightly larger than the optimal moisture content.