卢文斌,张栋,何燕新,等.三向应力作用下柱状节理岩体强度破坏特性试验研究[J]. 河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787. 2024100032.

LU W B,ZHANG D,HE Y X, et al．Experimental study on strength failure characteristics of columnar jointed rock mass under triaxial stress[J].Journal of Henan Polytechnic University( Natural Science)，doi:10.16186/j.cnki.1673-9787. 2024100032.

三向应力作用下柱状节理岩体强度破坏特性试验研究(网络首发)

卢文斌，张栋，何燕新，拓志伟

1. 河南理工大学 能源科学与工程学院，河南 焦作 454000；2. 河南省煤矿岩层控制国际联合实验室，河南 焦作 454000；3. 山东农业大学 水利土木工程学院，山东 泰安 271018

摘要: 目的 金沙江白鹤滩水电站坝址区的柱状节理岩体具有结构面异常发育、各向异性特征显著、开挖后易松弛破裂等特点，为保证施工建设的安全性，需对其力学性质展开深入研究。方法 根据相似理论并采用石膏、河砂及水等相似材料制备不含节理的完整试样和具有不同节理倾角的六棱柱型模型试样，利用真三轴试验机开展单轴压缩和三轴压缩试验，根据试验结果分别绘制强度及变形随节理倾角变化曲线，重点研究柱状节理岩体在不同应力条件下的强度特征、应力-应变关系及其破坏模式。结果 结果表明：不同于完整试样，柱状节理模型试样的强度与变形在不同的应力环境下表现出显著各向异性力学特征，且节理面的存在对模型的强度弱化作用明显；两种类型试样的峰值强度随围压升高而增大，节理试样在单轴压缩下的强度及弹性模量随节理倾角β变化呈“U”型线，三轴压缩时试样峰值强度随β增大分为两种类型，即先减小后增大(σ₃=1MPa)和无明显变化规律(σ₃=1.5MPa,2MPa)；随着围压增大，节理试样的破坏形态从脆性转变为塑性，各向异性比R降低；根据试验结果对模型试样的破坏模式进行分类，总结了三维应力条件下柱状节理模型试样的4种典型破坏类型。结论 研究结果不仅能够深入了解柱状节理玄武岩工程力学特性，同时可为复杂节理岩体相关问题的理论研究和工程分析提供参考。

关键词: 柱状节理岩体；三轴压缩；白鹤滩水电站；峰值强度；破坏模式

doi:10.16186/j.cnki.1673-9787. 2024100032.

基金项目: 国家自然科学基金（4183000014）

收稿日期: 2024-10-23

修回日期: 2024-11-14

网络首发日期：2024-11-19

Experimental study on strength failure characteristics of columnar jointed rock mass under triaxial stress

LU Wenbin,Zhang Dong,HE Yanxin,Tuo Zhiwei

1.School of Computer Science and Technology, Henan Polytechnic University, Jiaozuo 454000, Henan, China；2. Henan International Joint Laboratory of Coalmine Ground Control, Jiaozuo 454000, Henan, China；3.School of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai’an 271018, Shandong , China

Abstract: Objectives The columnar jointed rock mass(CJRM) in the dam site area of Baihetan Hydropower Station of Jinshajiang River has the characteristics of abnormal development of structural surface, significant anisotropic characteristics, and easy to relax and rupture after excavation, etc. In order to ensure the safety of the construction, it is necessary to carry out an in-depth study on its mechanical properties. Methods According to the similarity theory, the complete specimen without joints and the hexagonal prismatic model specimen with different joint inclinations were prepared by using similar materials such as gypsum, river sand and water, and uniaxial compression tests and triaxial compression tests were carried out by using true triaxial testing machine. Based on the experimental results, the strength and deformation curves were plotted, and the strength characteristics, stress-strain relationship and damage modes of CJRM under different stress conditions were investigated. Results The test results showed that, unlike the intact specimens, the strength and deformation of the columnar joint model specimens showed significant anisotropic mechanical characteristics under different stress environments, and the presence of joint surfaces had a significant effect on the weakening of the strength of the model; the peak strength of the two types of specimens increased with the increase of the peripheral pressure, and the strength and elastic modulus of the joint specimens under uniaxial compression with the change of the nclination angle β showed a ‘U’ line, and the peak strength of the specimens in triaxial compression with the increase of β was divided into two types, i.e., it decreased firstly and then increased (σ₃=1MPa) and there was no obvious rule of change (σ₃=1.5MPa,2MPa); With the increase of the peripheral pressure, the damage modes of the joint specimens changed from brittle to plastic, and the anisotropy ratio R decreased; Based on the results of the test of the model specimen damage mode; the damage modes of the model specimens were classified according to the test results, and four typical damage types of the specimens under three-dimensional stress conditions were summarised. Conclusions The results of the study could not only provide an in-depth understanding of the engineering mechanical properties of columnar jointed basalt, but also provided a reference for the theoretical study and engineering analysis of the problems related to complex jointed rock mass.

Key words: columnar jointed rock mass; triaxial compression; Baihetan Hydropower Station; peak intensity; destruction mode