干溪沟隧道岩溶整治分析

研究目的:灰岩地段岩溶发育复杂多变,对隧道施工和结构影响较大,结合对渝怀线干溪沟隧道施工中多处溶洞的处理,对岩溶处理进行总结、反思。研究方法:在详细查明溶洞发育规模、范围及溶洞充填物岩性组合特征后,对基础处理方案进行比选。研究结果:对干溪沟隧道揭示的各个岩溶溶洞采取有效的处理措施进行治理,并取得良好的效果。研究结论:岩溶发育复杂多变,整治时需因地制宜,对症下药;施工中遇到充填溶洞时,在未探明基础充填深度的情况下,应适当扩大开挖净空,为探测、结构处理提供空间及自由度预留条件;地下工程穿越地下水水平循环带且其排泄基准面下切较深(区段多见深切沟谷)时,充填溶洞处理则可不考虑地下水的影响,空溶洞则按干岩溶管道处理,但仍应预留排水通道,以防止雨季时地下水堵塞,水位上升至线路标高后形成水害;动静结合的框架式结构基础应考虑列车通过时的冲击荷载等不确定因素影响,适当增加安全储备。

Analysis of Treatment of Karst in Ganxigou Tunnel

Research purposes: The development of karst in limestone area is complicated and changeable.The purposes of this study are to sum up experiences of solving karst problems in combination with the treatment of karst in Ganxingou Tunnel on Yuhuai railway.Research methods:The proper measures for treatments of foundation shall be selected and adopted after knowing the(development) scale and range,and lithologic features of filiing materials by doing detailed investigation.Research results:All karst caves in Ganxingou Tunnel have been treated effectively and good result has been obtained.Research conclusions:Properly different treatments shall be adopted according to different conditions because the(development) of karst is complicated and changeable.When the depth of filling material is unknown,expanding the(excavation) area to provide enough space and freedom degrees for the detection and structural disposal is appropriate.When the tunnel passes through groundwater circulation zones and the draining base-level is deeper(many deep(ravines) in the section),the impact of groundwater shall be ignored.The karst cave shall be treated as dry one,but the drainage channels should be reserved for avoiding the groundwater flooding the cave.More security coefficient should be remained for the impact force and other uncertain factors affecting the structural foundation with dynamic and static framework by train passing through.