基于塑性体积率的地下厂房初次支护时机  

Timing of Initial Support for Underground Plant Excavation Based on Plastic Volume Rate

作　　者：杨峰[1] 贾朝军 戴梁 雷明锋[1] 施成华[1] 张强[3] YANG Feng;JIA Chao-jun;DAI Liang;LEI Ming-feng;SHI Cheng-hua;ZHANG Qiang(School of Civil Engineering,Central South University,Changsha 410083,China;Guizhou Transportation Venture Capital Co.,Ltd.,Guiyang 550081,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]中南大学土木工程学院,长沙410083 [2]贵州交通创业投资有限公司,贵阳550081 [3]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《长江科学院院报》2025年第3期133-140,共8页Journal of Changjiang River Scientific Research Institute

基　　金：“十四五”国家重点研发计划项目(2023YFB2603900);国家自然科学基金项目(52378421)。

摘　　要：为解决大型地下厂房分层开挖过程中,最佳初次支护时机难以确定的问题。基于隧道全断面开挖过程的横向变形特征,引入塑性体积率描述围岩开挖后发生塑性变形部分体积与开挖部分围岩总体积之比。根据不同应力释放率下隧道横断面位移释放率与纵向收敛变形曲线(LDP)特征,以位移释放率为纽带,提出了基于塑性体积率的地下厂房施工分层开挖过程初次支护时机确定方法。研究结果表明以塑性体积率描述的围岩变形演化规律更直观,突破了基于位移释放率方法中位移演化临界状态难找及无法应用于地下厂房分层开挖不同层初次支护时机确定的难题。某抽水蓄能电站地下主厂房二维和三维开挖数值计算结果表明所提出的基于塑性体积率的支护时机确定方法具有较好的规律性,可为大型地下工程分层开挖设计及施工提供参考依据。To address the challenge of determining the optimal timing for initial support during layered excavation in large underground powerhouses,we present a concept of plastic volume ratio to quantify the volume of rock mass undergoing plastic deformation to the total volume of excavated rock mass.Based on the lateral deformation characteristics of the entire cross-section during tunnel excavation,we propose a method for determining the timing of initial support in layered excavation processes based on the plastic volume ratio.This method takes into account the displacement release rate,along with the characteristics of the transverse displacement release rate and the longitudinal convergence deformation curve(LDP)under different stress release rates.The research demonstrates that the evolution of rock mass deformation,as described by the plastic volume ratio,offers a more intuitive understanding.This method overcomes the challenges associated with identifying the critical state of displacement evolution and the difficulty in determining the timing of initial support for different layers during layered excavation,as encountered when using the displacement release rate method.By conducting two-dimensional and three-dimensional numerical calculations for excavations in the underground main powerhouse of a pumped-storage power station,we demonstrate consistent performance of the proposed method.It can serve as a valuable reference for the design and construction of layered excavation in large underground projects.

关 键 词：地下厂房 初次支护时机 塑性体积率 分层开挖 位移释放率 

分 类 号：TV22[水利工程—水工结构工程]