倾斜薄层炭质板岩隧道围岩大变形特征及其卸荷破坏防控对策研究  

Characteristics of large deformation in tunnel surrounding within inclined thin-layered carbonaceous slate and its countermeasures against unloading failure

作　　者：阳军生[1] 杨喜锋 方星桦 谢亦朋 刘伟龙 ILYAS Ahbanouch YANG Jun-sheng;YANG Xi-feng;FANG Xing-hua;XIE Yi-peng;LIU Wei-long;ILYAS Ahbanouch(School of Civil Engineering,Central South University,Changsha,Hunan 410075,China;School of Civil Engineering,Central South University of Forestry and Technology,Changsha,Hunan 410004,China;Guangzhou Metro Construction Management Co.,Ltd.,Guangzhou,Guangdong 510220,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南林业科技大学土木工程学院,湖南长沙410004 [3]广州地铁建设管理有限公司,广东广州510220

出　　处：《岩土力学》2024年第12期3728-3737,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金高铁联合基金项目(No.U1934211)。

摘　　要：针对云南香丽高速公路11座典型倾斜薄层炭质板岩隧道,通过围岩变形监测、离散-连续耦合数值分析手段,研究了围岩大变形特征和卸荷变形破坏机制,并提出了相应防控对策。结果表明:(1)倾斜薄层炭质板岩隧道围岩变形受开挖卸荷和施工扰动影响大,围岩变形具有量值大、速率快、持续时间长的特点,拱部沉降大于水平收敛,为围岩卸荷大变形,整体呈现出非对称的空间分布特征;(2)围岩变形破坏随台阶施工进一步发展,上台阶开挖后,洞身左拱肩围岩出现弯折破坏,形成初始卸荷区域,具有显著的非对称特点,随着中、下台阶施工步序推进,左拱肩围岩的弯折破坏进一步发展,隧道拱部与右拱肩的围岩也逐渐产生朝向左侧的剪切滑移破坏,最终导致拱部卸荷破坏区域的整体扩张;(3)地层预加固是控制倾斜薄层炭质板岩隧道围岩变形的主要有效手段,同时可结合降低施工扰动、优化支护时机与参数等方面对围岩变形进行综合处置。We conducted monitoring of peripheral rock deformation and performed discrete-continuous coupling numerical analysis on 11 typical inclined thin-layered carbonaceous slate tunnels of the Yunnan Shangri-la-Lijiang Expressway.This study investigated the large deformation characteristics and unloading failure mechanisms of peripheral rock in these tunnels,and proposed corresponding countermeasures.The results indicate that:(1)The peripheral rock deformation of inclined thin carbonaceous slate tunnels is significantly influenced by excavation unloading and construction disturbances.The deformation is characterized by large quantitative values,rapid rates,and long durations.Additionally,crown settlement is greater than horizontal convergence,indicating significant unloading deformation of the peripheral rock,which exhibits asymmetric spatial distribution characteristics.(2)Peripheral deformation failure further develops with the construction of each step.After excavating the upper step,bending failure occurs in the peripheral rock on the left shoulder of the tunnel,forming an initial unloading area with pronounced asymmetric characteristics.As construction progresses through the middle and lower steps,the bending failure of the left shoulder’s peripheral rock continues to develop,while shear-slip failures gradually occur in the crown and right shoulder,ultimately leading to an expansion of the overall unloading failure area.(3)Pre-reinforcement of the strata is the primary effective method for controlling the deformation of inclined thin-layered carbonaceous slate.This approach can be combined with strategies to reduce construction disturbances and optimize the timing and parameters of support for the comprehensive treatment of peripheral deformation.

关 键 词：隧道 倾斜薄层炭质板岩 离散-连续耦合分析 卸荷大变形 防控对策 

分 类 号：TU454[建筑科学—岩土工程]