高地应力区缓倾互层岩体无砟轨道隧道底部隆起的成因分析及整治方案  

Cause Analysis and Treatment Scheme for Bottom Heave of Ballastless Track Tunnel in Nearly Horizontally Interbedded Rock Mass with High Geostress

作　　者：肖小文[1,2] 王立川[1,3] 阳军生[1,2] 张学民[1,2] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学重载铁路工程结构教育部重点实验室,湖南长沙410075 [3]成都铁路局,四川成都610082

出　　处：《中国铁道科学》2016年第1期78-84,共7页China Railway Science

基　　金：国家自然科学基金资助项目(51378505)

摘　　要：某高地应力区缓倾互层岩体无砟轨道隧道建成通车后,部分区段因隧道底部持续隆起而引起结构开裂、破坏。在实施预应力锚索(杆)加固方案后,底部隆起趋势仍未抑止,为此对该隧隧道底部隆起原因进行详细的调查分析。在现场实测和实验资料的基础上,采用FLAC2D数值软件建立隧道平面应变模型,研究隧道底部隆起的原因;对预应力锚索(杆)锚固和钢管桩结合中空锚杆注浆加固两方案进行模拟,比较二者的整治效果。结果表明:高地应力、隧道底部下伏缓倾互层岩体及仰拱下部存在软弱岩层是导致隧道底部隆起的主要原因;预应力锚索(杆)加固方案虽能一定程度抑制隧道底部的隆起,但不能显著改善隧道底部结构的受力状态,因此不能得到理想的整治效果;钢管桩结合中空锚杆注浆加固方案不仅能有效抑制隧道底部的隆起,而且能明显改善隧道底部结构的受力状态,同时通过注浆又可抑制隧道底部软弱岩层的进一步劣化,防止病害持续发展,显然此方案更适用于该隧道底部隆起的整治。A ballastless track tunnel, constructed in nearly horizontally interbedded rock mass with high geostress, bottom heave occurred continuously in some sections after it was put into service, which caused cracks and failure developed in the bottom structure. The heave trend didn＇t cease after the execution of anchorage treatment using pretensioned cables tunnel were investigated and analyzed in detail. （bolts）. In this paper, the causes for bottom heave of Based on in-situ monitoring and experimental data, the plane strain model of tunnel was constructed with the FLAC2D numerical software to study the causes for bottom heave. Two treatment schemes, namely, anchoring with pretensioned cables （bolts） and strengthening using steel tube piles and grouted hollow bolts were both simulated, and their treatment effects were compared. The results proved that high geostress, nearly horizontally interbedded rock mass underlying and the weak layer of broken rock mass existed under tunnel invert were the main causes. The treatment scheme of anchoring with pretensioned cables （bolts） could inhibit bottom heave to some extent. However, the loading conditions of bottom structure were not improved obviously, which made the treat- ment effect non-ideal. Strengthening using steel tube piles and grouted hollow bolts not only could inhibit bottom heave but also improve obviously the loading conditions of bottom structure. Meanwhile, grouting could stop the further deterioration of the weak layer below tunnel invert and prevent the disease from continuous development. So this scheme was testified to be more appropriate for treating the bottom heave of tunnel.

关 键 词：铁路隧道 高地应力 缓倾互层岩体 底部隆起 成因分析 整治方案 

分 类 号：U475.2[机械工程—车辆工程]