【作者】 孙杰；

【导师】 韩立军； 薛志胜；

【作者基本信息】 中国矿业大学 ， 土木水利（专业学位）， 2023， 硕士

【摘要】 近二十年来,我国许多矿区开展了大规模矿井资源整合,主要针对小煤窑开采后的破坏区内遗留的优质煤炭资源,进行资源整合并回收。其中,房柱式开采形成的采空区(下文简称房采区)是一种资源整合矿井经常遇到的复杂工况。房柱式开采通过在各个矿房间留设煤柱以保证作业安全,这种开采方式不仅破坏了原有煤层及顶板岩层的完整性,而且遗留的煤柱造成了大量的煤炭资源浪费。因此,如何在密布房采区条件下布置长壁综放工作面是该类煤炭资源安全高效回收的关键。其中,穿越房采区巷道的安全掘进对于保证后续煤炭资源的开采,具有重要的战略意义。本文以中煤集团山西华昱能源水泉煤业有限公司9~#煤层一盘区集中回风巷掘进工程为背景,针对巷道穿越房采区过程中可能遇到的顶板破碎、垮落、空顶区等严重影响巷道安全掘进及后期围岩与支护结构稳定的关键问题,通过理论分析、室内试验、数值模拟和现场应用等技术手段,开展穿越房采区巷道壁后充填注浆围岩稳定控制效应研究。本文研究主要得到以下几方面的成果:(1)通过现场钻孔取样的方式,取得原位的岩样,试验确定相应的基本力学参数;并通过单因素分析法,分析水灰比、粉煤灰掺量、水玻璃掺量、减水剂对房采区充填材料性能影响规律,明确最优掺量区间,进而确定正交试验各影响因素及水平,再利用正交试验法改进充填材料配比,最终发现了适用于水泉煤业房采区壁后充填的最优配比为水泥:粉煤灰(3:7)、水灰比(1.2)、减水剂(0.6%)、水玻璃(4.0%)。(2)根据Talbol级配理论,利用自主设计的注浆试验系统,分析了不同Talbol指数下的破碎煤体、破碎岩体的注浆固结体力学特性,发现随着Talbol指数的增加,破碎煤岩体的注浆固结体峰值强度、弹性模量等指标,都表现出先增后减的特征。除此以外,还发现随着Talbol指数的增加,固结体的破坏模式有由延性向脆性转化的趋势。(3)根据原位探测的房采区分布特点,利用离散元分析软件3DEC建立相应的数值模型,分析了模型在原岩应力、不同采动应力影响下的房采区遗留煤柱与顶板的响应特征,发现在采动应力影响下,遗留煤柱被迅速压坏,直接顶基本垮落,巷道掘进范围内为破碎的煤岩体,不具备结构性与承载能力;基于以上分析结果,探讨了不同充填加固高度下巷道掘进的可行性,发现在充填10m以上时,巷道掘进围岩能够维持短时稳定,从而保证巷道的安全掘进。(4)利用COMSOL Multiphysics多场耦合软件,推导了流固耦合的理论方程;分别分析了注浆范围为3m、4m、5m、6m、7m时的动态注浆压力与注浆孔布置参数,并利用3DEC数值模拟软件,分析了采动应力影响下,不同注浆范围的围岩动态响应特征,从而确定了合理的壁后注浆范围。(5)将以上研究成果在现场进行了工业性试验,监测结果表明,巷道围岩控制效果良好,能够为巷道围岩与支护结构稳定使用提供技术保障。该论文有图56幅,表31个,参考文献99篇。更多还原

【Abstract】 In the past two decades,many mining areas in China have carried out large-scale integration of mine resources,mainly aiming at the high-quality coal resources left in the damaged areas after the mining of small coal kilns,and carried out resource integration and recovery.Among them,the goaf formed by house-pillar mining(hereinafter referred to as house-mining area)is a complex working condition often encountered in resource integration mines.Room and pillar mining not only destroys the integrity of the original coal seam and roof strata,but also causes a lot of waste of coal resources.Therefore,how to arrange the longwall fully mechanized caving face under the condition of dense mining area is the key to the safe and efficient recovery of such coal resources.Among them,the safe excavation of the roadway through the housing mining area has important strategic significance for ensuring the subsequent mining of coal resources.This thesis takes the central return air roadway excavation project in the 1 pan area of 9#Coal seam of China National Coal Group Shanxi Huayu Energy Shuiquan Coal Industry Co,LTD as the background,aiming at the key problems that may be encountered in the process of roadway crossing the house mining area,such as roof breakage,caving and empty roof area,which seriously affect the safety of roadway excavation and the stability of surrounding rock and supporting structure in the later stage.By means of theoretical analysis,laboratory test,numerical simulation and field application,the stability control effect of surrounding rock filling and grouting after passing through the roadway wall of house mining area is studied.The main results of this study are as follows:(1)In-situ rock samples are obtained by in-situ drilling and sampling,and the corresponding basic mechanical parameters are determined by test;Through single factor analysis,the influence law of water-cement ratio,fly ash content,water glass content and water reducing agent on the performance of filling materials in Fang-mining area was analyzed,the optimal mixing range was defined,and then the influencing factors and levels of orthogonal test were determined.The orthogonal test method was used to improve the filling material ratio,and finally it was found that the optimal filling ratio suitable for the wall backfilling in Fangmining area of Shuiquan coal industry was cement: Fly ash(3:7),water-cement ratio(1.2),water reducing agent(0.6%),water glass(4.0%).(2)According to Talbol grading theory,the mechanical characteristics of grouting consolidation of broken coal and rock mass under different Talbol indices are analyzed by using the self-designed grouting test system.It is found that with the increase of Talbol index,the peak strength and elastic modulus of grouting consolidation of broken coal and rock mass all show the characteristics of first increase and then decrease.In addition,it is found that with the increase of Talbol index,the failure mode of the consolidated body changes from ductile to brittle.(3)According to the distribution characteristics of the mined area detected in situ,a corresponding numerical model was established by using discrete element analysis software3 DEC.The response characteristics of the model between the coal pillar and the roof in the mined area under the influence of raw rock stress and different mining stresses were analyzed.It was found that under the influence of mining stress,the coal pillar was crushed rapidly,the direct roof basically collapsed,and the coal and rock masses were broken in the range of roadway excavation.Lack of structural and carrying capacity;Based on the above analysis results,the feasibility of roadway excavation under different filling reinforcement heights is discussed.It is found that the surrounding rock of roadway excavation can maintain short-term stability when the filling is more than 10 m,so as to ensure the safety of roadway excavation.(4)The theoretical equations of fluid-structure coupling were deduced by using COMSOL Multiphysics software.The dynamic grouting pressure and the layout parameters of grouting holes when the grouting range is 3m,4m,5m,6m and 7m are analyzed,and the dynamic response characteristics of surrounding rock under the influence of mining dynamic stress are analyzed by using 3DEC numerical simulation software,so as to determine the reasonable grouting range behind the wall.(5)The monitoring results show that the control effect of roadway surrounding rock is good,which can provide technical support for the stable use of roadway surrounding rock and supporting structure.This thesis has 56 figures,31 tables and 99 references.更多还原