强夯法处理娄新高速公路岩溶塌陷地基的现场试验研究

摘要

Taking the project of karst collapse foundation treated by dynamic compaction in the construction of Lou-Xin expressway as an example,main parameters of dynamic compaction method,dynamic compaction test and its effects were analyzed.The test was conducted when 1000 kN·m and 4000 kN·m tamping energy were adopted.Meanwhile,the measurement work was also performed,including each tamping settlement of the tamped area,total settlement,ground uplift deformation around the tamping pit and influence scope.The results indicate that the optimum tamping times were 1 1 when 4 000 kN·m tamping energy was adopted.The compac-tion efficiency achieves more than 90%,which is much higher than that when 2 000 kN·m tamping energy was utilized.It could reinforce the karst collapse foundation effectively.Taming number of dynamic penetration after dynamic compaction increases obviously,which changes vastly from 1 to 12m in depth.It shows that the effective influence depth of 4 000 kN·m tamping energy reaches the depth of 12 meters.%以娄新高速公路岩溶塌陷地基强夯加固工程为背景，对强夯法的主要参数设计、强夯试验和强夯加固岩溶地基效果进行分析。分别采用2000 kN·m、4000 kN·m夯击能进行强夯试验，并对夯坑的每击夯沉量、总夯沉量及夯坑周围地面隆起变形量和影响范围进行监测。试验结果表明：在4000 kN·m夯击能下最佳夯击次数为11击，夯实效率达到90％以上，远高于2000 kN·m夯击能的夯实效率，可以有效地加固岩溶塌陷地基。强夯后动力触探击数明显增加，1～12 m变化明显，表明4000 kN·m夯击能的影响深度达到了12 m。