深路堑内浅埋层状软岩隧道锚特性试验研究  

Experimental Research on the Characteristics of Shallow Layered Soft Rock Tunnel-type Anchorage in Deep Cutting

作　　者：乔雷涛[1] 康炜[1] 文强[1] QIAO Leitao;KANG Wei;WEN Qiang(China Railway First Survey and Design Institute Group Co.Ltd,Xi'an,Shaanxi 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道工程学报》2022年第10期47-52,共6页Journal of Railway Engineering Society

基　　金：中国铁建股份有限公司科研计划课题(17-C06-2);中铁第一勘察设计院集团有限公司科研课题(院科18-13)。

摘　　要：研究目的:浅埋层状软岩隧道锚锚塞体与围岩相互作用的变形特征及承载机制复杂,难以用规范或工程类比进行分析研究,为研究隧道锚的变形规律、破坏特征及承载特性,通过现场开展1∶10缩尺模型试验,确定隧道锚的变形特征及承载力安全系数,探明软岩、浅埋、层理面等因素对隧道锚的影响,最终对隧道锚进行安全稳定性评价。研究结论:(1)在各级荷载下,隧道锚的变形从后锚面开始产生并向四周围岩衰减,锚体与左右侧围岩的变形呈较规则的对称双驼峰形;(2)在设计荷载下,锚塞体的变形最大,最大变形值为0.054mm,根据相似原理获得原型隧道锚在运营期的最大变形为0.5 mm;(3)隧道锚的极限承载力高达18倍设计荷载,锚塞体在极限荷载下致使正上方浅埋岩体发生斜向上拱起破坏,破裂面由层理面原始裂缝扩展延伸,致使破坏范围超过4倍洞径;(4)隧道锚的变形限值和围岩安全系数均满足规范要求,验证了隧道锚的安全稳定性;(5)本研究成果可为油溪长江大桥隧道锚系统安全评估提供可靠的依据,也可为相关工程提供技术参考。Research purposes: The deformation characteristics and bearing mechanism of the interaction between anchor plug body and surrounding rock of shallow layered soft rock tunnel-type anchorage are complex, and it is difficult to analyze and study with specifications or engineering analogies. In order to study the deformation law, failure characteristics and bearing characteristics of tunnel-type anchorages, the deformation characteristics and bearing capacity safety factor of tunnel-type anchorages are determined through on-site 1 ∶10 scale model tests, and the effects of soft rock, shallow burial, bedding plane and other factors on tunnel-type anchorages are explored. Finally, the safety and stability of tunnel-type anchorages are evaluated. Research conclusions:(1) The deformation of the tunnel-type anchorage occurs from the back anchorage surface and attenuates to surrounding rock under all levels of loads. And the deformation of the anchorage plug and the surrounding rock on the left and right sides presents a symmetrical double hump shape.(2) Under the design load, the deformation of the anchorage plug is the largest, and the maximum deformation is 0.054 mm, and the predicted maximum deformation of the prototype tunnel-type anchorage is about 0.5 mm.(3) The ultimate bearing capacity of the tunnel-type anchorage reaches 18 times of the design load. Under the ultimate load, the anchorage plug carries the shallow buried rock mass directly above to have the inclined upward arch failure. The fracture surface comes from the bedding plane original crack to expand and the failure range exceeds 4 times the tunnel diameter.(4) All these show that the deformation limit and the safety factor of surrounding rock meet the requirements of the specification and tunnel-type anchorage is safe and stable.(5) The research results can provide a reliable basis for the safety evaluation of the tunnel-type anchorage system of Youxi Yangtze River Bridge, and also provide technical reference for related projects.

关 键 词：油溪长江大桥 隧道锚 缩尺模型试验 变形承载特性 

分 类 号：U45[建筑科学—桥梁与隧道工程]