板状页岩单轴压缩实验及断裂力学分析

发布时间：2018-01-07 12:34

本文关键词：板状页岩单轴压缩实验及断裂力学分析　出处：《煤炭学报》2017年05期 　论文类型：期刊论文

【摘要】：基于板状页岩的单轴压缩试验,研究了含共线闭合裂隙页岩的裂纹扩展规律,从断裂力学角度,解释了裂纹起裂顺序,推导了板状页岩的脆性断裂准则及抗压强度,给出了断裂韧性的求取方法,得到:含预制裂隙页岩的抗压强度劣化程度较弹性模量大;破坏后宏观裂纹分为两类,一类为表面平整、光滑的拉裂纹,另一类为呈锯齿状、有明显压痕的压剪裂纹;预制裂隙内端比外端更容易起裂,起裂角范围为46°~86°;裂隙间距越小岩桥越容易搭接贯通;裂纹尖端起裂方向只和θ有关,和KⅡ无关;裂隙尖端的内端应力强度因子较大,更易起裂;共线双裂纹模型的优势裂纹角为β_m=0.5arctan f~(-1)。
[Abstract]:Uniaxial compression test of plate Shale Based on collinear crack closed fracture shale expansion law, from the point of view of fracture mechanics, explains the crack initiation sequence, deduced the brittle fracture criterion and compressive strength of plate shale, gives the fracture toughness calculation method: deterioration of prefabricated fractured shale the compressive strength is high elastic modulus; after the destruction of the macro crack is divided into two categories, one for the smooth surface, smooth crack pattern, the other is serrated, shear crack has the obvious indentation pressure; the inner end of the outer end of prefabricated crack more easily than crack initiation angle range of 46 degrees ~86 degrees; the smaller the distance between the rock bridge fracture more easily through the lap; crack tip crack direction and theta, and K II; the stress intensity factor of the crack tip in the larger end, more easy to crack; crack edge of two collinear cracks model angle beta _m= (-1) 0.5arctan f~.

【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;中国科学院武汉岩土力学研究所;中国矿业大学(北京)资源与安全工程学院;
【基金】：国家自然科学基金资助项目(51574218) 国家科技重大专项资助项目(2016ZX05060) 中国科学院战略性先导科技专项(B类)资助项目(XDB10040200)
【分类号】：TE311
【正文快照】： 中国页岩气资源丰富,可采储量达到31.57万亿m3,占全世界总量的15%[1],页岩的渗透率极低[2],为了实现页岩气的高效稳产,各国学者开展水力压裂实验来研究裂缝扩展规律[3-4],由于水力压裂裂缝扩展在试件内部进行,不便观察,故笔者采用高压水射流技术,在板状页岩上预制两共线裂隙,

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