杨石扣,孙宽,邓正定,等. 深埋多隧洞开挖围岩分区破裂机制研究[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2024040037.

YANG S K, SUN K,  DENG Z D, et al． Study on zonal fracture mechanism of surrounding rock in deep-buried multi-tunnel excavation[J]. Journal of Henan Polytechnic University( Natural Science) ， doi: 10.16186/j.cnki.1673-9787. 2024040037.

深埋多隧洞开挖围岩分区破裂机制研究(网络首发)

杨石扣，孙宽，邓正定，胡新伟

江西理工大学 土木与测绘工程学院, 江西 赣州341000

摘要: 目的 深埋隧洞开挖卸荷后，围岩往往出现分区破裂这一特殊结构性破坏现象，容易引起隧洞发生剧烈变形、突水和大规模塌陷等工程灾害。目前围岩分区破裂研究侧重于单隧洞，而实际工程中常见的多隧洞围岩分区破裂机制尚不清晰。方法 为探究深埋多隧洞开挖卸荷后的围岩分区破裂机制，以锦屏二级引水隧洞为研究背景，基于应变软化模型，建立引水隧洞数值模型，研究深埋多隧洞开挖卸荷后围岩分区破裂形态、破裂带最大径向距离、破裂带数目等随强度参数、变形参数、剪胀角的变化规律，比较强度参数、变形参数、剪胀角对围岩分区破裂形态的影响。结果 结果表明：多隧洞开挖卸荷后，四个洞室的破裂化形态呈一定的对称关系，2#隧洞围岩分区破裂迹象更为严重，1#隧洞右侧分区破裂化程度比左侧更加剧烈；随着内摩擦角、粘聚力、弹性模量的减小，或剪胀角的增大，围岩分区破裂越来越剧烈；泊松比主要影响破坏区域的位置，泊松比越小，隧洞左右两侧破坏区域逐渐向围岩深处转移，而隧洞拱顶和拱底处的破坏区域逐渐靠近隧洞壁；强度参数对围岩分区破裂形态的影响最大，变形参数次之，剪胀角的变化对围岩分区破裂化效果影响相对较小。结论 研究结果揭示了深埋多隧洞开挖卸荷围岩分区破裂化机制，为深部地下多洞室开挖围岩支护设计提供理论支撑。

关键词: 深埋隧洞；围岩；应变软化；分区破裂；强度参数；开挖卸荷

doi: 10.16186/j.cnki.1673-9787. 2024040037

基金项目: 国家自然科学基金项目（52368048，51739006）；中国博士后科学基金项目（2017M611678）；江西省自然科学基金项目（20224BAB213045）；江西省教育厅科学技术研究项目（GJJ190500）；赣州市科技计划项目（赣市科发[2019]60号）

收稿日期：2024-04-20

修回日期：2024-05-27

网络首发日期：2026-03-09

Study on zonal fracture mechanism of surrounding rock in deep-buried multi-tunnel excavation (Online)

YANG Shikou, SUN Kuan, DENG Zhengding, HU Xinwei

School of Civil Engineering and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China

Abstract: Objectives After the excavation and unloading of deep tunnels, the surrounding rock often suffers from special structural damage phenomena such as zonal fracture, which can easily cause engineering disasters such as severe deformation of the tunnel, water inrush, and large-scale collapse. At present, research on the zonal fracture of surrounding rock focuses on single tunnel, while the zonal fracture mechanism of surrounding rock in multiple tunnels in practical engineering is not yet clear. Methods In order to explore the mechanism of rock fragmentation after excavation unloading of deep buried multi-tunnels, the diversion tunnels at Jinping II Hydropower Station were used as the research background. Based on the strain softening model, a numerical model of the diversion tunnels was established. The variation patterns of the zonal fracture morphology of surrounding rock, the maximum radial distance of fracture zones, the number of fracture zones with the strength parameters, deformation parameters, and shear dilation angle after the excavation unloading of deep-buried multi-tunnels were studied, and the effects of strength parameters, deformation parameters and shear dilation angle on the fracture shape of the surrounding rock partition were compared. Results The results show that after multi-tunnel excavation and unloading, the fracturing patterns of the four caverns exhibit a certain symmetrical relationship. The signs of zonal fracturing in the surrounding rock of the 2# Tunnel are more serious, and the degree of zonal fracturing in the right side of the 1# Tunnel is more severe than that of the left side. As the internal friction angle, cohesion, and elastic modulus decrease, or the shear dilation angle increases, the zonal fracture of surrounding rock becomes more severe. The Poisson's ratio mainly affects the location of zonal fractures of surrounding rock. The smaller the Poisson's ratio is, the fractured zones on the left and right sides of the tunnel are farther away from the tunnel wall, while the closer fractured zones at the arch top and bottom are to the tunnel wall. The strength parameters have the greatest influence on the zonal fracture morphology of surrounding rock, followed by the deformation parameters, the effect of changes in shear dilation angle has relatively little effect on the zonal fracture of surrounding rock. Conclusions The research results reveal the zonal fracture mechanism of surrounding rock after excavation unloading of deep buried multi tunnels, and provide theoretical support for the design of surrounding rock support for deep underground multi-cavity excavation.

Key words: deep buried tunnel; surrounding rock; strain softening; zonal fracture; strength parameters; excavation unloading