红砂岩碎石土高填方路基强夯加固时的动应力扩散及土体变形试验研究

利用4种不同的夯击能量（840,960,1 080,1 200 kN.m）对红砂岩填土路基分别进行动应力扩散和夯后路基的沉降试验研究。试验结果表明：强夯对红砂岩填土路基的加固效果明显,动应力在水平方向上的有效加固宽度从2～3 m变化至3～4 m,在竖直方向上的有效加固深度从3.5～4.0 m变化至5.0～6.0 m;随着夯击次数的增加,动应力在有效加固范围内的增加亦更加明显,但在3～5击后基本稳定;4种夯击能量在土体中产生的变形为4.0～6.0 m的变化比较显著,但当深度超过6.0 m的之后,产生的沉降量就几乎相等,而且在不同夯击能量以及在不同夯击次数下,其最终的下沉位移在5.5 m处都为5.0～7.0 cm,因此这4种夯击能量在红砂岩碎石土高填方路基中的有效加固深度基本上都在4.0～6.0 m之间。这些试验成果可为以后同种条件下的山区公路加固提供参考。

TEST STUDY ON SOIL DYNAMIC STRESS DIFFUSION AND DEFORMATION DURING DYNAMIC COMPACTION IN ROADBED PRIMED WITH LARGE GRANULE RED SANDSTONE

The dynamic stress diffusion and the roadbed settlement after tamp are studied in four classes of tamping energy,i.e.840,960,1 080,1 200 kN.m,respectively,in roadbed primed with large granule red sandstone.The test results show that the effective reinforcement distance ranges from 2-3 m to 3-4 m and the effective reinforcement depth ranges from 3.5-4.0 m to 5.0-6.0 m.The dynamic stress change is more markedable with the tamp time increasing,but it approaches stable when the tamping time increases 3-5 times.The deformation change markedable with the above different classes of tamping energy in depth of 4.0 to 6.0 m,but when the depth excesses 6.0 m,the settlements are almost equal,and the final deformation at depth of 5.5 m is 5.0-7.0 cm.The reliability and validity of the tamper construction design are proved by a series of tests.