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深部软岩巷道高凸钢带—锚网索复合支护耦合效应研究
Study on High Convex Strip and Bolt-mesh-cable Combined Supporting Effect for Deep Soft Rock Roadway
【作者】 李志平;
【作者基本信息】 河南理工大学 , 岩土工程, 2009, 硕士
【摘要】 本文基于高凸钢带-锚网索复合支护技术在鹤壁九矿-420m水平软岩试验巷道的成功应用,采用理论分析、FLAC3D数值模拟、LS-SVM围岩位移非线性预测、工程监测等手段对其支护机理及效应做了较为系统深入的研究,主要内容及相关研究成果如下:1)采用文献计量学的方法对我国煤矿井巷支护技术的发展现状做了统计分析,发现锚杆支护特别是锚杆系列联合支护技术应用广泛,而钢带研究基本没引起重视。认为高凸钢带-锚网索复合支护的研究具有一定的理论和应用价值。2)明确给出高凸钢带支护参数的理论公式。分析既有钢带的结构效应,对比凸显高凸钢带的优越性。认为凸台的存在可以适应深部软岩的有害大变形,高强度高刚度能有效限制岩巷的时空非均匀变形破坏。3)建立了高凸钢带-锚网索复合支护数值模型。采用FLAC3D数值模拟方法,对比分析了无支护、普通锚带支护、新型支护条件下围岩应力、围岩变形、锚杆(索)受力、高凸钢带受力等情况,初步研究了高凸钢带-锚网索复合支护机理及其应用。认为高凸钢带-锚网索复合支护效果良好。4)参考河南、两淮、山西等地区石炭二叠纪岩石地质工程资料,将石炭二叠纪含煤岩系岩石分为:砂岩、粉砂岩、砂质泥岩、泥岩、煤五组,并归纳出各岩组的现场鉴定法及力学性质测试参数。综合分析了基于Hoek-Brown准则、基于RMR值评分、经验判断等分组法的特点,参考国家工程岩体分级标准(GB50218-94),推荐了石炭二叠纪含煤岩系岩体地质力学分组法,并提出了适用于FLAC3D数值模拟的岩体力学参数。并通过分析五组围岩状况巷道变形破坏及钢带受力情况,初步研究高凸钢带-锚网索复合支护的适用性。5)基于LS-SVM法建立了深部岩巷顶部离层量非线性预测模型。并编制了相应的Matlab程序,来预测深部围岩非线性变形,结果与FLAC3D数值模拟结果基本一致,认为采用LS-SVM法进行深部围岩位移非线性预测是科学可行的。6)参考鹤壁九矿-420m水平软岩试验巷道的高凸钢带-锚网索复合支护设计方案及工程监测结果,与本文FLAC3D数值模拟和LS-SVM预测结果进行对比分析,发现其结果基本吻合,进一步验证了本文研究的科学性、准确性和有效性。
【Abstract】 Based on perfect reinforcement effect of high convex strip-bolting support technology achieved by a soft rock roadway at -420 level (depth of 640m) in Hebi No.9 Coal Mine, theoretical analysis, numerical simulation with FLAC3D, nonlinear prediction of surrounding rock displacement by LS-SVM, and in comjunction with inversion techniques of in-situ monitoring were carried out in our study.The following is the main research contents and the results in this dissertation.1.In accordance with the statistics of coal roadway support from main journals during last 30 years in China, though bolting support, especially combined support, has been widely applied, there exist deficiencies in studies of strip. In this paper, the roadway support technology was categorized into traditional support, metal support, bolting support and combined support, of which the characteristics and applications are totally analyzed.2.Theoretical formulas of high convex strip-bolting support parameters are raised. It is concluded that the convex bed of strip-band can adapt to large deformation of high pre-stressed bolting, and that the high strength and rigidity of strip can bear extremely large axial force and moment.3.The FLAC3D numerical simulation model of roadway section using the high convex strip-bolting support has been established. Considering the conditions of no support, general bolting support and high convex strip-bolting support, several regular conclusions of high convex strip-bolting support are put forward.4.The rock type of Permo-Carboniferous coal-bearing formation is classified as five kinds which are sandstone, siltstone, sandy mudstone, mudstone and coal. In-situ check and mechanical parameters of carboniferous rock are induced. The mechanical parameters for numerical simulation with FLAC3D are designed on the basis of Hoek-Brown criterion, RMR value score, and Chinese National Standards for Engineering Rock Mass Classification. By means of the analyses of the roadway deformation and strip strength conditions, surrounding rock classification of combined support of high convex strip-bolting is stated.5.Nonlinear predicted models of deep rock roadway basing on the LS-SVM are established, and the relevant Matlab codes are compiled. It is shown that nonlinear deformation predicted by LS-SVM is suitable for roadways excavated in deep weak rock masses.6.To take a haulage roadway at -420 level (depth of 640 m) in Hebi No.9 Coal Mine as an example, a design scheme is brought forward to fit for the deep roadway support. By successive observation and analysis of the convergence of roadway, the correctness, effectiveness and scientificalness of this study are further confirmed.
【Key words】 deep gateway; soft rock roadway; high convex strip; numerical simulation; support vector machine;