全风化软岩填料的工程特性及其高填路堤沉降特性分析

Engineering Characteristics of Fully Weathered Soft Rock Filling and Settlement Analysis of High Fill Embankment

为研究全风化软岩填料的工程特性,对压实度为96%、94%、93%的全风化软岩开展了室内承载比试验以及压缩试验,并据此对其特殊填筑路段高填路堤开展了数值模拟研究。结果表明,全风化软岩填料的膨胀率为1.29%~1.87%,不属于膨胀土;压实度越大则CBR值也呈增大的趋势,其值符合规范要求,可用作路堤填料。压缩模量随压实度的增大而增大,不同压实度对应的湿化变形率分别为2.03%、3.24%、3.86%,其湿化变形率总体不高。软岩高填路堤沉降随深度的增加呈先增大后减小的趋势,在路堤高1/3处取得最大值。随着软岩高填路堤压实度的增加,其沉降量逐渐减小,但差距不大;随着含石量的增加,其沉降量先减小后增大,在含石量为55%时达到最小沉降。因此在软岩填筑过程中,依靠提高压实度来减小路堤沉降不够经济,可采取增大含石量至55%左右来减小路堤沉降量。

To study the engineering characteristics of fully weathered soft rock filling, we carried out indoor bearing ratio tests and compression tests on the fully weathered soft rock with compaction degrees of 96%,94% and 93% respectively.On this basis, we conducted a numerical simulation on the high fill embankment as its special filled section.The results show that the expansion rate of the fully weathered soft rock is 1.29%~1.87%,indicating that it does not belong to expansive soil.The CBR value also tends to increase when the compaction degree gets higher.Its value meets the specification requirements, making it able to be used as embankment filling.The compression modulus is enhanced with the increase in compaction degree, and the wetting deformation rates corresponding to different compaction degrees are 2.03%,3.24% and 3.86%,respectively, which are not high generally.The settlement trend of high fill embankment made of soft rock is increasing first and then decreasing with the increase in depth and peaks at 1/3 of the embankment height.As the compaction degree of the high fill embankment is elevated, the settlement is reduced gradually, but the difference is not big.With the increase in stone content, the settlement first decreases and then increases and is minimized when the stone content is 55%.Therefore, it is not economical to reduce embankment settlement by increasing compaction degree during soft rock filling, while enhancing the stone content to about 55% is a good choice instead.