摘要
为了研究深部巷道锚喷层卸压孔径大小对围岩应力释放与喷层承载强度的影响,对6种不同孔径的12个试件进行了单轴压缩试验,研究了不同孔径条件下水泥石试件应力-应变关系,以及试件抗压强度、峰值应变与弹性模量的变化,得到了试件的破坏形态与失稳模式。结果表明:孔洞水泥石试件孔径越大,试件破裂粘结面积与试件抗压强度越低;随着孔径尺寸由0mm向50mm增加,试件抗压强度、峰值应变与弹性模量呈减小趋势,且减小趋势变缓,衰减率分别是52.74%、22.31%与34.63%,孔径尺寸与试件抗压强度、峰值应变与弹性模量可采用负线性函数表征,但线性关系依次减小;0~20mm孔径水泥石试件裂纹起裂于孔壁上下斜角,破坏于上下斜角孔壁对角线,称为小孔径破坏形态,而30~50mm孔径水泥石试件起裂于左右侧孔壁,破坏于孔壁两侧垂直劈裂,称为大孔径破坏形态,30mm以上试件破坏形态明显具有孔洞试件结构特征;依据大小孔径破坏形态差异,不同横向孔径水泥石试件失稳模式分为剪切错动失稳与片状劈裂失稳。
In order to study the influence of releasing-hole size of bolting shotcrete in deep gateway on the stress releasing and bearing strength,uniaxial compression tests of 12 specimens with 6 different pore sizes were carried out,stress-strain relationship of the specimens was discussed,the effect of hole size on the compressive strength,peak strain and elastic modulus,poisson ratio was studied,and the failure form and instability mode were obtained.The results show that:the larger the pore size of the cement specimen,the lower the rupture bond area and compressive strength of the specimen.As holediameter rises from 0mm to 50mm,the compressive strength and elastic modulus declines slowly,and the attenuation rates are 52.74%,22.31%and 34.63%,respectively;the relationships between hole size and compressive strength,peak strain and elastic modulus can be represented by negative liner functions,but the linear relationship decreases.The crack in cement specimen with 0mm to 20mm hole-diameter starts at the hole-walls in the upper and lower diagonal angles of specimen,the specimen is damaged at diagonal crack of hole-walls in the upper and lower diagonal angles,which is named small hole-size failure form.The crack in cement specimen with 30mm to 50mm hole-diameter started at the walls in the left and right holes of specimen,the specimen is damaged at both sides of hole-walls in vertical split,which is named large hole-size failure form,the failure mode of specimens above 30mm is obviously characterized by the structure of holes.The instability mode of cement specimen with different-size horizontal hole is divided into shear dislocation instability and planar splitting.
作者
孙广建
张洋
辛亚军
常晓亮
SUN Guang-jian;ZHANG Yang;XIN Ya-jun;CHANG Xiao-liang(Yongmei Group Co.,Ltd.,Yongcheng 476600,China;Shuihe Coal Mine,Yongmei Group Co.,Ltd.,Yongcheng 476600,China;School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Jiaozuo 454000,China)
出处
《煤炭工程》
北大核心
2022年第7期109-115,共7页
Coal Engineering
基金
国家自然科学基金资助项目(51374091)
深井瓦斯抽采与围岩控制技术国家地方联合工程实验室开放基金项目(SJF201801)。
关键词
深部巷道
锚喷层
水泥石试件
横向孔径
单轴压缩
应力应变
失稳模式
deep roadway
bolt-shotcreting layer
cement specimen
diameter of horizontal holes
uniaxial compression
stress-strain
instability form
