深埋软岩隧洞让位支护原理及应用技术框架  

Principle and Application Framework of Displacement Yielding Support for Deep Buried Tunnel in Red Soft Rock

作　　者：张建平 黄威 王环玲[1,2] 王如宾[1,2] 马建伟 徐卫亚[1,2] ZHANG Jianping;HUANG Wei;WANG Huanling;WANG Rubin;MA Jianwei;XU Weiya(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai Univ.,Nanjing 210098,China;Research Institute of Geotechnical Engineering,Hohai Univ.,Nanjing 210098,China;POWERCHINA Kunming Engineering Co.,Ltd.,Kunming 650051,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学岩土工程科学研究所,南京210098 [3]中国电建集团昆明勘测设计研究院有限公司,昆明650051

出　　处：《三峡大学学报（自然科学版）》2023年第5期12-18,86,共8页Journal of China Three Gorges University：Natural Sciences

基　　金：云南省重大科技专项计划项目(202102AF080001)。

摘　　要：软岩大变形问题是深埋软岩隧洞面临的重大工程挑战和核心关键技术问题.本文总结了从采取刚性支护硬顶的方法发展到采用柔性支护利用围岩自承能力的让压方法的历程,通过分析国内外软岩大变形案例,以滇中引水工程为例,总结滇中软岩变形特征,认为滇中深埋软岩隧洞大变形问题,如采用以防止冲击地压和解决不均压问题的让压锚杆支护,将有一定的局限性,甚至无效.滇中深埋软岩隧洞软岩大变形问题往往还与赋存地质物理环境高外水压力作用有关.文中提出复杂地质条件下深埋软岩隧洞让位支护理论与技术方法,让位支护理论与让压支护理论基础和原理不同,其不是让抵抗冲击地压为目标,而是让变形位移为核心,软岩隧洞施工中“持续变形、边支边让”为核心思想,在保证水工隧洞安全稳定的条件下充分释放岩体的主体变形能,保障软岩隧洞支护、衬砌的安全稳定.该理论方法可在变形力学机理上解决软岩大变形和高外水压力强作用的关键核心技术问题.文中给出了软岩隧洞让位支护系统技术方法,包括系统让位锚杆、让位锚索、约束混凝土、可缩动钢拱架结构及其让位支护体系技术.The problem of large deformation in soft rocks is a significant engineering challenge and a core technical issue for deeply buried soft rock tunnels.This paper summarizes the evolution from rigid support with a hard roof to employing flexible support that utilizes the self-supporting capacity of surrounding rock,through the development of the“yielding pressure”method.Based on an understanding of the deformation characteristics of soft rocks in central Yunnan Province,it is suggested that relying solely on yielding pressure anchor support,aimed at preventing impact pressure and addressing uniform pressure problems,will have limitations and might even be ineffective for dealing with the issue of large deformation in deeply buried soft rock tunnels.The large deformation issue in these tunnels is often influenced by high external water pressure in the geological and physical environment.This paper introduces the displacement yielding support theory and technical approach for deeply buried soft rock tunnels under complex geological conditions.Unlike the conventional yielding pressure support theory,the displacement yielding support theory is not focused on minimizing impact pressure,but rather centers around deformation displacement.The core idea is to“support while yielding,start flexible and then become rigid”,allowing the main deformation energy of the rock mass to be released fully,while ensuring the safety and stability of the hydraulic tunnel,as well as the support and lining of the soft rock tunnel.This theoretical approach offers a solution to the key technical challenges of large deformation in soft rocks and strong external water pressure effects based on deformation mechanics principles.The paper presents the displacement yielding support system technical methods for soft rock tunneling,including a systematic displacement yielding anchor rod,displacement yielding anchor cable,displacement yielding constraint concrete,adjustable steel arch structure,and the displacement yielding support system.

关 键 词：软岩隧洞 软岩大变形 高外水压力 让位支护 滇中引水工程 

分 类 号：P642[天文地球—工程地质学]