黄土改良红砂岩的试验及路用性能研究

兰州某地铁车站深基坑开挖遇到大量红砂岩,红砂岩直接作为路基填料会造成路基垮塌等工程事故。为了研究红砂岩作为路基填料的适宜性,以及对改良红砂岩最优配比及改良效果和工程性能进行研究。对不同配比及不同含水率的黄土-红纱岩改良土进行击实试验、直接剪切试验和固结压缩试验。试验结果表明:30%黄土掺量且含水率达到8%的红砂岩改良土的干密度达到最大值2.11g/cm~3;其抗剪强度指标内摩擦角和黏聚力得到大幅提高及其压缩性能得到改善,工程性能得到了一定提高。初步确定了改良红砂岩作为路基填料的可行性。

Experimental Study on Mixing Red Sandstone with Loess and its Performance

A large number of red sandstone is excavated in the deep excavation of a subway station in Lanzhou .There will be subgrade collapse and engineering accidents if the red sandstone is directly used as the subgrade filler .In order to test the suitability of red sandstone as a subgrade filler and determine the optimal matching and improvement effect and engineering properties of improved red sandstone .The compaction test ,direct shear test and consolidation compression test are carried out when mixing red sandstone with loess by different ratio and water content .Results of the trial indicat-ed that the dry density of improved red sandstone with 30% loess and 8% water reached a maximum of 2 .11 g/cm3 ;the angle of internal friction and cohesion of the shear strength index are improved greatly and its compression performance is improved .Therefore ,the feasibility of improved red sandstone as subgrade filler is preliminarily determined .