摘要
为研究裂隙对冻结黏土动态力学性能的影响,制作了不同位置、不同条数、不同长度和倾角的预制裂隙冻土试样,利用Ф50 mm杆径的分离式Hopkinson压杆装置进行了不同预制裂隙冻结黏土的冲击压缩试验。研究表明,侧面预制裂隙对人工冻结黏土试样动态抗压强度和弹性模量的弱化程度要大于端面预制裂隙,当侧面预制裂隙倾角垂直时,试样的强度劣化系数最大,弹性模量最小,分别为25.99%、172 MPa;端面裂隙条数为1～2条时强度劣化系数增长幅度较为明显,侧面裂隙条数为1～2条时增幅较小,弹性模量随裂隙条数的增加逐渐减小。当端面裂隙长度为8 mm、12 mm和16 mm时,强度劣化系数分别为0.47%、7.97%、22.22%,弹性模量分别降低了3.59%、15.69%、44.77%,随着裂隙长度的增大,冻土抵抗破坏的能力变弱。
To study the effects of the pre-existing flaws on dynamic mechanical property of frozen clay,the frozen clay specimens with different flaw positions,flaw numbers,flaw lengths,and angles are tested using a system of split Hopkinson pressure bar(SHPB)with the diameter of 50 mm.Experimental results show that the deterioration degree of pre-existing flaws at side surface on dynamic strength and elasticity modulus are larger than that at end surface of specimen.The maximum strength deterioration coefficient and minimum elasticity modulus are found at 0°flaw angle at side surface,and their corresponding values are 25.99%and 172 MPa,respectively.Additionally,elasticity modulus of frozen clay decreases with the increase of flaw numbers.Meanwhile,there has a larger growth value about strength deterioration coefficient when the end surface flaw number increases from one to two,while at side surface of specimen is not obvious.The capability of frozen clay to resist deformation and destruction under dynamic impact load decreases with the increase of flaw lengths,the strength deterioration factor and reduce value of elasticity modulus are 0.47%,7.97%and 22.22%at 8 mm,12 mm and 16 mm flaw length,and the correspond decrease value are 3.59%,15.69%,44.77%,respectively.
作者
黄坤
马芹永
马冬冬
HUANG Kun;MA Qin-yong;MA Dong-dong(School of Civil Engineering and Architecture,Ministry of Education,Anhui University of Science and Technology,Huainan 232001,China;Engineering Research Center of Underground Mine Construction,Ministry of Education,Anhui University of Science and Technology,Huainan 232001,China)
出处
《科学技术与工程》
北大核心
2018年第25期224-229,共6页
Science Technology and Engineering
基金
国家自然科学基金(50874003)资助
