摘要
宜万铁路马鹿箐隧道"+978"大型富水溶洞容量巨大,水压高,充填物为饱水淤泥质粉质黏土夹碎石、块石及孤石,颗粒细、强度低、施工风险大。在排水减压的条件下,根据Ⅰ、Ⅱ线溶洞段不同的工程地质条件,Ⅰ线溶洞段采用了"注浆加固、超前支护、加强结构"的处理方案,Ⅱ线溶洞段采用了"回填反压、盖挖通过、加强结构"的处理方案。针对溶洞充填物强度低,荷载大的特点,采用双层喷混凝土支护形式的初期支护,有效控制了围岩变形,并承担了大部分围岩压力,为二次衬砌承受雨季突增水压力提供了有利条件,隧道结构安全性监测结果表明溶洞段结构安全可靠。
The large scale and waterrich cave of ＂ ＋ 978＂ Cave in Malujing Tunnel on YichangWanzhou Railway features large dimension and high water pressure, it is filled with watersaturated silty clay mingled with gravel, stones and boulders. The tough status, that is, tiny particles and low strength in the cave zone, leads to tremendous construction risks. Under the circumstances of decompression and drainage, also according to different geological conditions in cave zones in line I and line II, we adopt treatment schemes of ＂grouting reinforcement, advanced supporting, strengthening the struc ture＂ for the cave in line I , as well as ＂antipressure backfilling, cover excavation passing through , strengthening the structure＂ for the cave in line II. The cave filler has only a very low strength, however, it must bear very heavy loads. In response to this feature, an initial support of double shot concrete lining has been chosen for the cave zone. The lining has borne the most of the rock pressure, and the deformation of the surrounding rock has been effectively controlled, this has provided a favorable condition for the secondary lining to withstand the water pressure, which might suddenly increase in the coming rainy season. Monitoring results in the tunnel has shown that the structure in cave zone is safe and reliable.
出处
《铁道建筑技术》
2012年第2期30-33,38,共5页
Railway Construction Technology
关键词
隧道工程
溶洞
支护结构
安全监测
tunnel engineering
cave
supporting structure
safety monitoring
