采动影响下断层活化机理及影响因素分析  

Analysis of fault activation mechanism and influencing factors caused by mining

作　　者：于秋鸽 张华兴[1,2] 张玉军[1,2] 邓伟男[1,2] 张刚艳[1,2] YU Qiuge;ZHANG Huaxing;ZHANG Yujun;DENG Weinan;ZHANG Gangyan(Coal Mining and Design Branch,China Coal Research Institute,Beijing 100013,China;Coal Mining and Design Department,Tiandi Science and Technology Co.,Ltd.,Beijing 100013,China)

机构地区：[1]煤炭科学研究总院开采研究分院,北京100013 [2]天地科技股份有限公司开采设计事业部,北京100013

出　　处：《煤炭学报》2019年第S01期18-30,共13页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51604151);天地科技开采设计事业部青年基金资助项目(KJ-2018-TDKCZL-10)。

摘　　要：为了研究断层活化机理及影响因素,考虑断层水的作用,根据断裂力学建立了断层带岩体原始裂隙损伤发育力学模型及断层带岩体滑移力学模型,根据此模型分析了断层活化的机理,并得到影响断层活化的因素主要有断层带岩体水平应力和垂直应力的比值λ、断层带岩体是否含水、断层带岩体弹性模量E、断层带泊松比μ、断层倾角θ1、断层带岩体内摩擦角φ、断层带岩体黏聚力c等。同时,以断层露头处台阶下沉值的大小为断层活化程度判别标准,利用FLAC 3D内置FISH语言进行编程验证了以上因素对断层活化的影响。研究结果表明:①当λ<1时,随着λ的增加,断层带岩体原始裂隙越不容易扩展,断层活化的可能性降低;当λ>1时,随着λ的增加,断层带岩体原始裂隙越容易扩展,断层活化的可能性增加。②=2\*GB3当断层带岩体含有水时,水压的存在不仅导致断层带岩体原始裂隙容易扩展,同时水还对断层带岩体滑移具有润滑作用,增加了断层活化的可能性。③随着E的增加,断层带岩体原始裂隙越不容易扩展,断层活化的可能性降低;随着μ的增加,断层带岩体原始裂隙越容易扩展,断层活化的可能性增加。④断层露头处的台阶下沉值取决于断层带岩体滑移量和采动影响下断层露头处的正常下沉值,随着θ1的增加,断层带岩体滑移量可能减小,但是采动影响下断层露头处的正常下沉值急剧增加导致断层露头处的台阶下沉值增大,断层活化的可能性增加。⑤随着φ,c的增加,断层带岩体原始裂隙越不容易扩展,断层带岩体越不容易滑移,断层活化的可能性降低。研究结果为分析断层活化机理及断层露头处建筑物和构筑物的保护提供借鉴。To study the mechanism of fault damage activation,the mechanical models for fracture damage development and rock mass slipping under water pressure were established based on fracture mechanics.From the two mechanism models,the main influencing factors including the ratio of horizontal stress to vertical stressλ,whether there was water or not in fault zone,elastic modulus E,Poisson’s ratioμ,fault angleθ1,internal friction angleφand cohesion c and so on were obtained.At the same time,the results were verified by numerical simulation using FLAC 3D built-in FISH language according to the criterion of fault activation degree based on the value of step subsidence at fault outcrop.The results show that the possibility of fault activation would increase withλwhen it is smaller than 1,while the possibility would decrease whenλincreases and is larger than 1 for the reason that the fault zone fracture is easier to expand whenλis smaller than 1 and increasing,while it’s adverse whenλis larger than 1.When there is water existing in fault zone,water would promote possibility of fault activation for water pressure wouldn’t only expand the fracture,but also lubricate the rock mass sliding.With the increase of E,the original fracture of the rock mass in the fault zone is not easy to expand,and the possibility of fault activation is reduced,while it’s reverse according toμ.The step subsidence value at the fault outcrop depends on normal subsidence value at fault outcrop without fault existing and rock mass slipping value influenced by mining,the rock mass slipping value would decrease at fault outcrop whenθ1 increases,but the normal subsidence would increase sharply.As the result,the step subsidence value at fault outcrop increases as well as the possibility of fault activation.At the same time,when internal friction angleφand cohesion c increase,the fault zone fracture is harder to expand and the possibility of fault activation decreases.

关 键 词：断层活化 影响因素 裂隙损伤发育 断层带岩体滑移 断层带岩体性质 开采沉陷 

分 类 号：TD325[矿业工程—矿井建设]