基于相似模拟实验的巷道变形特征及失稳危险判别研究
发布时间：2019-03-09 11:44
【摘要】：巷道(承担着通风、运输、行人及其他功能)在煤矿开采中扮演着重要的角色,巷道的稳定关系着煤矿的安全和高效生产。近年来由于开采强度的增大和开采深度的增加,加上复杂的地质条件,采动应力和构造应力的叠加,使得井下开采区域巷道容易产生大的变形、失稳和破坏,甚至会由于冲击地压、矿震或强烈矿压显现等造成巷道的损坏。如何对处于应力影响范围内的巷道的稳定进行监测,及时对巷道变形、失稳等危险状况作出预警,是煤矿安全监测中的重要研究内容。针对巷道变形失稳监测的实际,本文建立巷道围岩变形破坏模拟试验及应变测试系统,在通过材料强度配比试验确定相似模型所需材料最佳配比的基础上,开展了巷道围岩变形过程的物理相似模拟研究,测试了二向载荷条件下受载巷道模型变形破坏过程中的宏观应力、应变的变化特征,同时利用预先植入的光纤光栅传感器测试了巷道围岩内部应变的变化特征;并结合RFPA数值模拟结果,分析了巷道围岩变形破坏机理;最后根据巷道围岩内部弯曲拉伸应变变化的时序特征,提出了基于内部应变监测的围岩失稳判别条件。全文主要取得以下研究成果:(1)进行了试验模型所需相似材料的强度配比实验,测定了沙子石蜡混合物8种配比情况下的主要力学参数,确定了沙子/石蜡为100:12作为相似模型所需材料的最佳配比。(2)建立了巷道围岩变形破坏模拟试验系统,开展了巷道围岩变形过程的物理相似模拟试验,模型整体变形破坏过程的全应力应变曲线可以划分为四个阶段:压密阶段、受载阶段、破坏阶段和破坏后阶段。(3)测试并分析了巷道模型受载变形破坏过程中顶板下沉和支撑压力变化情况,以及垂向、横向载荷变化特征和围岩内部应变变化特征。(4)应用RFPA2D软件,对巷道模型进行了平面应力分布集中及平面裂纹生成发育扩展过程的数值模拟分析。(5)提出了基于内部应变监测的巷道围岩失稳判别条件:①应变呈渐增大趋势且其绝对值达到很大或者应变值在短时间内迅速增大;②应变表现出先上升后下降的趋势特征,或出现不规则的波动。本文为巷道围岩的实验模拟研究提供了新的思路,对深入了解巷道变形破坏及围岩失稳具有重要的理论价值和现实意义。
[Abstract]:Roadway (with ventilation, transportation, pedestrian and other functions) plays an important role in coal mining, the stability of roadway is related to the safety and efficient production of coal mine. In recent years, due to the increase of mining intensity and the increase of mining depth, coupled with complex geological conditions, the superposition of mining stress and structural stress makes the roadway in underground mining area easy to produce large deformation, instability and destruction. It can even cause roadway damage due to rock burst, mine earthquake or strong rock pressure behavior. How to monitor the stability of roadway under the influence of stress and give early warning to the dangerous condition of roadway deformation and instability is an important research content in coal mine safety monitoring. In view of the reality of deformation and instability monitoring of roadway, a simulation test and strain test system for deformation and failure of surrounding rock of roadway is established in this paper. On the basis of determining the best proportion of materials required by similar model through material strength matching test, The physical similarity simulation of deformation process of roadway surrounding rock is carried out, and the variation characteristics of macroscopic stress and strain in deformation and failure process of loaded roadway model under two-way load are tested. At the same time, the strain variation characteristics of surrounding rock of roadway were tested by pre-implanted fiber grating sensor. Combined with the results of RFPA numerical simulation, the deformation and failure mechanism of roadway surrounding rock is analyzed, and finally, according to the time series characteristics of the deformation and tensile strain change of roadway surrounding rock, the condition for determining the instability of surrounding rock based on internal strain monitoring is put forward. The main results of this paper are as follows: (1) the strength proportioning experiment of similar materials required for the test model was carried out, and the main mechanical parameters of sand paraffin mixture were measured under the condition of 8 kinds of mix ratio. The optimum proportion of sand / paraffin as the material needed for similar model is determined. (2) the simulation test system of deformation and failure of surrounding rock of roadway is established, and the physical similarity simulation test of deformation process of surrounding rock of roadway is carried out. The total stress-strain curves of the whole deformation and failure process of the model can be divided into four stages: compaction stage, loading stage, The failure stage and the post-failure stage. (3) the change of roof subsidence and support pressure and vertical direction in the process of deformation and failure of roadway model under load are tested and analyzed. The variation characteristics of transverse load and strain in surrounding rock. (4) using RFPA2D software, The numerical simulation and analysis of plane stress distribution concentration and plane crack growth are carried out for the tunnel model. (5) the criterion of surrounding rock instability based on internal strain monitoring is put forward: 1 the strain increases gradually. Trend and its absolute value is very large or strain value increases rapidly in a short time; (2) the strain showed a tendency of rising first and then decreasing, or appeared irregular fluctuation. This paper provides a new train of thought for the experimental simulation of roadway surrounding rock, and has important theoretical and practical significance for further understanding the deformation and failure of roadway and the instability of surrounding rock.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353
本文编号：2437419
[Abstract]:Roadway (with ventilation, transportation, pedestrian and other functions) plays an important role in coal mining, the stability of roadway is related to the safety and efficient production of coal mine. In recent years, due to the increase of mining intensity and the increase of mining depth, coupled with complex geological conditions, the superposition of mining stress and structural stress makes the roadway in underground mining area easy to produce large deformation, instability and destruction. It can even cause roadway damage due to rock burst, mine earthquake or strong rock pressure behavior. How to monitor the stability of roadway under the influence of stress and give early warning to the dangerous condition of roadway deformation and instability is an important research content in coal mine safety monitoring. In view of the reality of deformation and instability monitoring of roadway, a simulation test and strain test system for deformation and failure of surrounding rock of roadway is established in this paper. On the basis of determining the best proportion of materials required by similar model through material strength matching test, The physical similarity simulation of deformation process of roadway surrounding rock is carried out, and the variation characteristics of macroscopic stress and strain in deformation and failure process of loaded roadway model under two-way load are tested. At the same time, the strain variation characteristics of surrounding rock of roadway were tested by pre-implanted fiber grating sensor. Combined with the results of RFPA numerical simulation, the deformation and failure mechanism of roadway surrounding rock is analyzed, and finally, according to the time series characteristics of the deformation and tensile strain change of roadway surrounding rock, the condition for determining the instability of surrounding rock based on internal strain monitoring is put forward. The main results of this paper are as follows: (1) the strength proportioning experiment of similar materials required for the test model was carried out, and the main mechanical parameters of sand paraffin mixture were measured under the condition of 8 kinds of mix ratio. The optimum proportion of sand / paraffin as the material needed for similar model is determined. (2) the simulation test system of deformation and failure of surrounding rock of roadway is established, and the physical similarity simulation test of deformation process of surrounding rock of roadway is carried out. The total stress-strain curves of the whole deformation and failure process of the model can be divided into four stages: compaction stage, loading stage, The failure stage and the post-failure stage. (3) the change of roof subsidence and support pressure and vertical direction in the process of deformation and failure of roadway model under load are tested and analyzed. The variation characteristics of transverse load and strain in surrounding rock. (4) using RFPA2D software, The numerical simulation and analysis of plane stress distribution concentration and plane crack growth are carried out for the tunnel model. (5) the criterion of surrounding rock instability based on internal strain monitoring is put forward: 1 the strain increases gradually. Trend and its absolute value is very large or strain value increases rapidly in a short time; (2) the strain showed a tendency of rising first and then decreasing, or appeared irregular fluctuation. This paper provides a new train of thought for the experimental simulation of roadway surrounding rock, and has important theoretical and practical significance for further understanding the deformation and failure of roadway and the instability of surrounding rock.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353
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