超深竖井侧压力计算方法  

Lateral rock mass pressure calculation method for extra deep vertical shafts

作　　者：李尧[1] 董星 曹校勇[2] 徐平[2] 陈星历 LI Yao;DONG Xing;CAO Xiao-yong;XU Ping;CHEN Xing-li(School of Highway,Chang’an University,Xi’an 710064,Shaanxi,China;CCCC First Highway Consultants Go.,Ltd.,Xi’an 710075,Shaanxi,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]中交第一公路勘察设计研究院有限公司,陕西西安710075

出　　处：《长安大学学报（自然科学版）》2024年第4期87-96,共10页Journal of Chang’an University(Natural Science Edition)

基　　金：陕西省“特支计划”青年拔尖人才支持项目;中交第一公路勘察设计研究院有限公司科创基金项目(JTBZ2019-05)。

摘　　要：中国公路隧道竖井设计与施工主要借鉴煤炭、冶金等行业的经验,尽管在超深竖井建设方面取得了瞩目的成就,但相关设计理论远滞后于工程实践,在多座超特长隧道中超深竖井的建设过程中遇到多种挑战。针对隧道工程中超深竖井围岩压力计算难题,基于天台山2号竖井设计参数,结合已有实测围岩应力和损伤特征,使用三维有限差分模拟方法,假定爆破损伤区范围为1 m,建立560 m深竖井(包含Ⅲ-Ⅴ级围岩)数值模型,分析围岩应力分布特征,建立超深竖井侧压力计算方法。结果表明:围岩塑性区在竖井开挖线外1~2.5 m处;塑性区范围在同级围岩内随埋深增大而增大,在接近围岩等级变化处时减小;损伤区内围岩应力远小于其他区域,大主应力为切向应力,围岩成环作用显著;损伤区外的塑性区内大主应力为垂直应力。竖井开挖并支护后,竖井周边围岩应力状态显著变化,径向应力随埋深增加而持续增加,在接近围岩级别变化处和竖井底部时开始减小。围岩级别的改变显著影响切向应力和垂直应力的大小,而对径向应力影响较小。相比现行《公路隧道设计细则》(JTG/T D70—2010)推荐方法,提出的计算方法所得围岩压力更小,且更接近类似工程的实测结果和模拟结果,可为超深竖井围岩压力计算提供参考。The design and construction of highway tunnel shafts in China mainly relies on the experience of coal,metallurgy,and other industries.Despite significant accomplishments in constructing ultra-deep shafts,the design theory in this area significantly lags behind engineering practice.Throughout the construction of super-deep shafts in many long tunnels,numerous challenges have been faced.In order to address the issue of calculating the surrounding rock pressure in super-deep shafts for tunnel engineering,a three-dimensional finite difference simulation method was utilized based on the design parameters of the Tiantaishan No.2Shaft.The measured stress and damage characteristics of the surrounding rock was used,assumed a 1m range for the blasting damage zone and a 560m-deep numerical model of the shaft(comprising gradeⅢ-Ⅴsurrounding rock)was established.The analysis focused on the stress distribution characteristics of the surrounding rock and developed a calculation method for the lateral pressure of ultra-deep shafts.The results show that the plastic zone of the surrounding rock extended 1to 2.5mbeyond the shaft excavation line,with the range of the plastic zone increasing with burial depth in the same level of surrounding rock and decreasing near changes in surrounding rock grade.The inner surrounding rock exhibited lower stress compared to other areas,with the major principal stress being tangential stress and a significant ring formation effect in the surrounding rock.Additionally,the major principal stress in the plastic zone outside the damage area is vertical stress.After the excavation and support of the shaft,there is a noticeable change in the stress state of the surrounding rock.Radial stress increases with depth,decreases near the changing point of rock mass level and the bottom of the shaft.Variations in the surrounding rock level have a significant impact on tangential and vertical stress levels,while radial stress remains relatively unaffected.The proposed calculation method in this study showed sm

关 键 词：隧道工程 竖井 侧压力 径向应力 切向应力 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]