圆形洞室模型在双轴加载下的力学特征分析  

Mechanical Characteristics Analysis of Circular Cavity Model under Biaxial Loading

作　　者：李雪迎 任红磊 胡宝文 无 LI Xue-ying;REN Hong-lei;HU Bao-wen;无(College of Water Conservancy and Hydropower,Hebei University of Engineering,Handan 056038,China;Hebei Key Laboratory of Intelligent Water Conservancy,Handan 056038,China;Beijing Key Laboratory of Urban Underground Space Engineering,Beijing 100083,China)

机构地区：[1]河北工程大学水利水电学院,邯郸056038 [2]河北省智慧水利重点实验室,邯郸056038 [3]城市地下空间工程北京市重点实验室,北京100083

出　　处：《科学技术与工程》2022年第18期8013-8021,共9页Science Technology and Engineering

基　　金：河北省自然科学基金(E2019402256)。

摘　　要：为探究圆形洞室围岩在不同围压下加载过程中的力学特征变化,对制作的含圆形洞室的类岩石材料进行双轴加压试验,运用数字图像技术记录全场应变演化过程,并根据室内试验建立颗粒流模型,探究了围压对洞室围岩的抗压强度以及裂纹的发育的影响。结果表明:尺寸效应对模型的力学特征影响较大,圆形洞室模型峰值抗压强度随着洞室尺寸的增加而减小;当围压增大时,压剪作用增强,洞室模型的破坏模式由以张拉应变为主向拉剪复合破坏为主转变;圆形洞室应变集中区域会随着围压的增大由洞口上下侧向两帮转移;当围压逐渐增大,张拉作用被抑制,洞口两侧破坏程度逐渐增加,收缩变形程度逐渐增大;最后通过数值模拟验证了圆形洞室围岩在不同围压下加载过程中的力学变化特征。In order to explore the change of mechanical characteristics of surrounding rock of circular cavern under different confining pressures,biaxial compression tests were carried out on the rock-like materials containing circular caverns.The digital image technology was used to record the whole field strain evolution process,and the particle flow model was established according to the test to explore the influence of confining pressure on the compressive strength of surrounding rock of cavern and the development of cracks.The results show as follows.The size effect has a great influence on the mechanical characteristics of the model,and the peak compressive strength of the circular cavity model decreases with the increase of the cavity size.When the confining pressure increases,the compressive shear effect increases,and the failure mode of the cavern model changes from tensile strain to tensile shear composite failure.With the increase of confining pressure,the strain concentration area of circular cavity transfers from the upper and lower sides of the hole.When the confining pressure increases gradually,the tension is inhibited,the damage on both sides of the hole increases gradually,and the shrinkage deformation increases gradually.Finally,the mechanical variation characteristics of surrounding rock of circular cavern under different confining pressures are verified by numerical simulation.

关 键 词：相似材料 数字图像技术 双向加载 洞室围岩 离散元法 

分 类 号：TU458.4[建筑科学—岩土工程]