环境敏感区铁路路基岩溶地基处理新结构研究

Research on the New Structure of Railway Subgrade in Karst Ground Treatment in Environmental Sensitive Area

研究目的:黔张常铁路DK 49+556.00～DK 49+913.22段路基位于野猫河水库上游水源保护区附近,在紧邻该段路基、具有相同地质条件的土乐坪1号特大桥和土乐坪2号特大桥桩基施工过程中,附近稻田出现泥浆外泄现象,为避免该段路基岩溶注浆处理引起水源保护区水质污染,需研究一种新的岩溶地基处理措施,以代替传统注浆处理措施。研究结论:(1)环境敏感的饮用水源地附近,岩溶地基处理不宜采用注浆处理方式;(2)深埋式桩、复合梁板结构不仅解决了岩溶区地基塌陷对铁路安全产生的影响,还避免了引起饮用水源的污染;(3)路堤地段岩溶地基处理采用深埋式桩、复合梁板结构还可以起到节约用地的效果;(4)本研究成果具有良好的经济效益和社会效益,可应用于岩溶强发育区地基处理。

Research purposes： Subgrade of DK 49 ＋ 556. 00 ～ DK 49 ＋ 913. 22 in Qianjiang-Zhangjiajie-Changde railway located in upstream of Yemao river reservoir near the water conservation area. In the pile foundation construction process of Tuleping No. 1 and No. 2 large bridge adjacent to the subgrade,which have the same geological conditions,we found that the mud leaked to the paddy fields nearby. To avoid water pollution because of the karst grouting treatment in the water conservation area,it need a new karst ground treatment measure instead of the traditional method of karst ground treatment.Research conclusions：（1） Near the environmentally sensitive drinking water source areas,grouting is not suitable in karst ground treatment.（2） ＂Deeply buried pile,composite beam-plank structure＂not only can prevent the influence on railway of foundation collapse in karst area,but also can avoid water pollution near water source areas.（3） Using＂deeply buried pile,composite beam-plank structure＂in embankment in karst ground treatment can also save land.（4） This research results have good economic and social benefits,which can be effectively applied to the ground treatment in strong karst development areas.