摘要
为研究纵向裂隙分布位置对洞室围岩失稳特征的影响规律,通过无预制裂隙洞室模型及含不同位置预制裂隙洞室模型双轴加载试验,结合数字图像技术(DIC)对比分析了洞室模型宏观力学参数及破坏模式。试验结果表明,随侧压力系数(λ)增大,洞室模型峰值强度和峰值应变呈先增大后减小趋势,在λ=1时达到最大值,弹性模量与之相反,呈先减小后增大趋势;从破坏模式来看,λ<1时,洞室破坏模式主要由张拉破坏逐渐转为拉剪复合破坏,裂隙位于拱顶,底板破坏明显,而裂隙位于直墙和底脚处,拱顶及底脚均破坏严重,随λ增大,λ≥1时,模型破坏以张拉裂纹为主,相比其他两个位置的裂隙,裂隙位于直墙,洞室稳定性最差;在相同λ下,高应变集中区会随裂隙位置改变而发生转移,但高应变区主要集中在预制裂隙端及洞室两底脚处。
In order to study the influence of the distribution position of longitudinal cracks on the instability istics character-of surrounding rock of caverns,the macroscopic mechanical parameters and failure modes of cavern models were compared and analyzed by biaxial loading tests of cavern models without prefabricated cracks and cavern models with fabricated pre-cracks at different positions as well as combining with digital image technology(DIC).The test results show that with the increase of lateral pressure coefficient(λ),the peak strength and peak strain of the cavern model increase first and then decrease,and reach the maximum whenλ=1,while the elastic modulus decreases first and then increases.From the point of view of failure mode,forλ<1,the failure mode of the cavern is gradually changed from tensile failure to tensile-shear composite failure.The fracture is located at the vault and the bottom plate is obviously damaged,while the fracture is located at the straight wall and the bottom foot,and the vault and the bottom foot are seriously damaged.With the increase ofλandλ≥1,the failure of the model is mainly tensile crack.Compared with the other two positions,the fracture is located in the straight wall,and the stability of the cavern is the worst.Under the sameλ,the high strain concentration area will shift with the change of crack position,but the high strain area is mainly concentrated at the fabricated pre-crack end and the two bottom feet of the cavern.
作者
胡宝文
宋金科
李雪迎
刘会欣
栾亚伟
南博文
HU Bao-wen;SONG Jin-ke;LI Xue-ying;LIU Hui-xin;LUAN Ya-wei;NAN Bo-wen(School of Water Conservancy and Hydroelectric Power,Hebei University of Engineering,Handan 056006,China;Hebei Key Laboratory of Intelligent Water Conservancy,Handan 056006,China)
出处
《水电能源科学》
北大核心
2024年第6期115-119,共5页
Water Resources and Power
基金
河北省自然科学基金项目基础研究专项(E2020402087)
河北省自然科学基金项目(E2019402256)。
关键词
侧压力系数
数字图像技术
裂纹扩展
纵向单裂隙分布位置
起裂应力水平
lateral pressure coefficient
digital image technology
crack propagation
longitudinal single fracture tribution dis-position
crack initiation stress level
