摘要
在分析多个高应力地下工程破裂特征的基础上,将岩石峰前和峰后全过程力学行为纳入地下工程支护设计中,提出融合启裂强度因子和峰后脆–延转化因子的大型地下洞室应力-强度设计方法,简称“2S+”方法,充分考虑了岩石裂纹扩展机制和峰后力学行为。岩石单轴压缩试验中的启裂强度与现场初始地应力下最大主应力量值的比值构成启裂强度因子ISI,反映岩石内部裂纹扩展本质和围岩初始应力水平;工程围压范围内岩石脆性指标的下降速率构成峰后脆-延转化因子BDF,反映岩石峰后应力降低的大小、速率和脆-延性;支护强度根据收敛约束法的基本原理求解获得。基于多个典型地下洞室岩石ISI,BDF和地下洞室支护强度统计结果,建立围岩破坏模式和支护设计的“七分区”评价体系,并在多个大型地下工程实践中得到了成功应用。
Based on the analysis of failure characteristics of multiple underground engineerings under high in-situ stress condition,the mechanical behavior of rock before and after peak is incorporated into the support design of underground engineering.This paper establishes the stress-strength design method for huge underground engineering considering initial strength index and post-peak brittle-ductile transformation factor.The established support design method pays full attention to the rock crack propagation mechanism and post-peak mechanical behaviour.The initial strength index(ISI)is defined by the ratio of the crack initial strength of rock under uniaxial compression to the maximum principal stress of geostress,which reflects the crack propagation mechanism of rock and the initial stress level of surrounding rock.The post-peak brittle-ductile transformation factor(BDF)is defined by the decreasing rate of rock brittleness within engineering confining pressure,which demonstrates the magnitude and rate of post-peak stress reduction and rock brittleness.The support strength is obtained according to the basic principle of convergence-confinement method.A seven-zone evaluation system of surrounding rock failure mode and support design is established based on the statistical results of ISI,BDF and support strength of surrounding rock of several typical huge underground engineerings.The failure modes and support parameters of huge underground engineerings in Baihetan,Jinping II,Jiangbian,Yangfanggou hydropower station and Yixing pumped storage power station show the rationality and applicability of the established support design method.
作者
张春生
刘宁
陈建林
褚卫江
高要辉
张传庆
高阳
ZHANG Chunsheng;LIU Ning;CHEN Jianlin;CHU Weijiang;GAO Yaohui;ZHANG Chuanqing;GAO Yang(PowerChina Huadong Engineering Corporation Limited,Hangzhou,Zhejiang 310014,C4hina;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第1期51-64,共14页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(U1865203)。
关键词
岩石力学
启裂强度因子
峰后脆性转化因子
大型地下洞室
围岩破坏
支护设计
rock mechanics
initial strength index
post-peak brittle-ductile transformation factor
huge underground caverns
surrounding rock failure
support design
