铁路隧道穿越岩溶群区施工控制技术研究

Construction techniques for a railway tunnel passing through karst group area

文章以渝(重庆)怀(怀化)铁路板桃隧道为工程背景,阐述了该隧道穿越DK215+650～DK216+105段岩溶群区的施工技术.为确保施工工期,施工中采取了'先绕行后处理'的原则,设置施工迂回导洞绕行岩溶区,并通过横通道与正线相连.针对岩溶区内不同的溶洞类型分别采取跨越、支顶、锚喷支护、浆砌片石回填等技术措施,同时根据暗河与溶洞内的水流大小及流向采取了诸如涵洞、小桥等设施或开凿泄水洞将水排出洞外,安全稳妥地通过了455 m岩溶群区.本工程取得的经验可供类似工程施工中借鉴.

The paper describes the construction techniques on the section from DK215 ＋ 650 to DK216 ＋ 105, where group of karsts are encountered, for Bantao tunnel on Yu （Chongqing） Huai （Huaihua） railway. In order to guarantee the construction time limit for this project, a bypass adit was excavated to make a detour of the karst group area, it was connected with main tunnel by a transverse gallery. Measures such as spanning over, supporting, anchor bolts and shotcrete, backfilling by rubbles set in mortar, etc. were adopted according to the different types of karsts. Culverts, small bridges were adopted according to the amount and direction of flow of the underground river, drains were adopted to drain off the underground water. As a result, the 455 m long karst group area was overcome safely. The practice can be taken for reference by similar projects.