强夯法处理娄新高速公路岩溶塌陷地基的现场试验研究

Experimental study on dynamic compaction method applied in karst collapse foundation of Lou-Xin expressway

以娄新高速公路岩溶塌陷地基强务加固工程为背景，对强务法的主要参数设计、强务试验和强务加固岩溶地基效果进行分析。分别采用2000kN·m、4000kN·m务击能进行强务试验，并对务坑的每击务沉量、总务沉量及务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4000kN·m务击能下最佳务击次数为11击，务实效率达到90％以上，远高于2000kN·m务击能的务实效率，可以有效地加固岩溶塌陷地基。强务后动力触探击数明显增加，1～12m变化明显，表明4000kN·m务击能的影响深度达到了12m。

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.