论文部分内容阅读
试验路基以云贵铁路某填方路基为原型,试验路堤底部宽L=60 cm,路堤顶部宽l=10 cm,路堤高h=15 cm,采用室内模型试验研究了4组减震措施在逆冲断层作用下填方路基的变形响应。第1组是把路堤直接坐落在地基上,这组试验也是一组基本试验,其他试验组的试验结果可与该组试验结果进行对比;第2组是在路堤底部铺设一层土工格栅;第3组是在路堤中部和底部各铺设一层土工格栅;第4组是在路堤底部黏土层中打入预制的CFG桩,同时在路堤底部和中部各铺设一层土工格栅。试验中利用分离式位移计和百分表记录路堤的变形数据,通过对数据的处理分析研究路堤在不同加固措施下的变形破坏模式,研究结果表明:(1)在4组模型中,路基破坏主要是路堤本身产生了斜45°的裂缝;(2)在底部基岩错动量小于路堤高度13.6%时,路堤中加入两层土工格栅达到的减震效果最佳;当基岩错动量在路堤高度13.6%~20.5%之间时,CFG桩与路堤中加入两层土工格栅的减震措施最有效;(3)随着减震措施的加强,断层位移在地层中传播的角度变缓,影响范围加长,产生的震害程度降低了。研究结果对工程实践具有重要的指导意义。
The test embankment is based on a fill subgrade of Yungui-Guizhou railway. The width of the test embankment is L = 60 cm at the bottom, l = 10 cm at the top of the embankment and h = 15 cm at the embankment. Deformation Response of Filling Subgrade under Fault Action. The first group is the embankment is located directly on the foundation, this group of tests is also a set of basic tests, the test results of other test groups can be compared with the test results; the second group is laying a layer of geogrid at the bottom of the embankment; In the third group, a layer of geogrid is laid at the middle and bottom of the embankment. In the fourth group, prefabricated CFG piles are put into the clay layer at the bottom of the embankment, and a geogrid is laid at the bottom and the middle of the embankment respectively. The deformation data of the embankment were recorded by using separate displacement meters and dial indicators. The deformation and failure modes of the embankment under different reinforcement measures were analyzed through data processing and analysis. The results show that: (1) In the four models, Mainly because the embankment itself produces a 45 ° oblique crack. (2) When the bedrock motion at the bottom is less than 13.6% of the embankment height, the geogrid with two layers of embankments achieves the best damping effect. When the bedrock motion is at When the embankment height is between 13.6% and 20.5%, it is most effective to reduce the seismic load by adding two layers of geogrids between the CFG pile and the embankment. (3) As the shock absorption measures are strengthened, the fault propagation angle is slowed down in the strata , The scope of the impact is lengthened and the degree of damage caused by the earthquake is reduced. The research results have important guiding significance for engineering practice.