Abstract: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 lithology features of filling 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.