大断面巷道锚网索支护技术的研究与应用
发布时间：2018-11-22 09:00
【摘要】：随着地下矿开采强度与规模的扩大，为满足大型开采设备的使用、运输以及矿井通风等要求，巷道尺寸不断增加。巷道尺寸的增大降低了围岩的稳定性，这给巷道支护工作带来新的挑战。大断面巷道的支护已成为一个亟待解决的难题。 本文以纳林河煤矿大断面巷道支护问题为背景，通过现场调研、理论分析、数值模拟等研究手段，对大断面巷道围岩破坏机理及其锚网索联合支护技术进行研究，并针对纳林河煤矿的具体地质条件和支护问题提出相应支护对策。 （1）分析了大断面巷道变形破坏机理。大断面巷道开挖后，巷道围岩平衡时的三向应力失衡转变为二向应力，巷道两帮和顶底板均出现应力集中现象，造成巷道围岩强度的降低，最终导致围岩的变形和破坏。 （2）通过FLAC3D数值模拟软件，分析了大断面巷道尺寸对巷道稳定性的影响。研究结果表明，巷道断面积越大，围岩塑性区范围增大，，巷道宽度对巷道稳定性的影响尤其重大，当巷道宽度从4m增大到6.5m时顶板最大位移从65mm增大至85mm，造成巷道支护难度加大。 （3）分析了锚网索联合支护对大断面巷道的作用机理。巷道支护后，锚索和锚杆预紧力的作用可以使围岩重新恢复三向应力状态，有效控制围岩变形，从而维持巷道围岩的稳定。支护后锚索可以深入顶板围岩深处，对可能发生松动和破裂的岩石起到悬吊作用，由于大断面巷道跨度比较大，锚索还起到了减跨的作用，降低了顶板的沉降量；两帮的锚杆可以加固表面破碎煤体，使其同深部稳定煤体形成一个大的锚固体，抑制深部煤体发生离层，可以有效的控制巷道两帮的变形。 （4）通过FLAC3D数值模拟软件对锚杆长度、间排距、夹角、预紧力大小等对支护效果的影响。研究结果表明，增大锚杆长度可以使预紧力有效向围岩深部扩散，压应力主要作用区为锚杆1/2长度以内；锚杆间排距及夹角的减小可使锚杆之间的作用力相互叠加形成一个整体的压缩区，起到对围岩的整体加固作用；增大预紧力能够提高锚杆的主动支护效果，随着锚杆预应力的增大，锚杆群在围岩中产生的压应力的强度和范围都有所增加，锚杆预紧力为50KN时的最大主应力为0.02MPa，预紧力增大到200KN后最大主应力增大至0.09MPa。 （5）针对纳林河煤矿大断面巷道变形破坏特征及现有支护方案的不足，提出锚网索联合支护方案并在现场加以应用。现场监测结果表明，该支护方案有效控制了围岩变形，支护效果较为理想。
[Abstract]:With the expansion of underground mining intensity and scale, the size of roadway is increasing in order to meet the requirements of large-scale mining equipment, transportation and mine ventilation. The increase of roadway size reduces the stability of surrounding rock, which brings new challenge to roadway support. The support of large-section roadway has become a difficult problem to be solved. Based on the support problem of large section roadway in Nalinghe coal mine, the failure mechanism of surrounding rock and the combined support technology of anchor, mesh and cable are studied by means of field investigation, theoretical analysis, numerical simulation and so on. According to the concrete geological conditions and supporting problems of Nalinhe coal mine, the corresponding supporting countermeasures are put forward. The main contents are as follows: (1) the deformation and failure mechanism of large section roadway is analyzed. After the excavation of large section roadway, the three direction stress imbalance of roadway surrounding rock balance is changed into two direction stress, and the stress concentration phenomenon appears in both side of roadway and roof and floor, which results in the decrease of surrounding rock strength of roadway, and finally leads to the deformation and destruction of surrounding rock. (2) the influence of roadway size on roadway stability is analyzed by FLAC3D numerical simulation software. The results show that the larger the roadway area is, the larger the plastic zone of surrounding rock is, and the more the influence of roadway width on roadway stability is, when the roadway width increases from 4m to 6.5m, the maximum displacement of roof increases from 65mm to 85mm. The difficulty of roadway support is increased. (3) the action mechanism of bolting, mesh and cable combined support on large section roadway is analyzed. After roadway support, the action of anchor cable and bolt pre-tightening force can restore the three-way stress state of surrounding rock, control the deformation of surrounding rock effectively, and maintain the stability of roadway surrounding rock. After supporting, the anchor cable can go deep into the surrounding rock of the roof and suspend the rock which may be loosened and ruptured. Because of the large span of the roadway with large section, the anchor cable also plays the role of reducing the span and reducing the settlement of the roof. The bolt of the two sides can strengthen the surface broken coal body, make it form a large anchor body with the deep stable coal body, restrain the deep coal body from breaking off, and effectively control the deformation of the two sides of the roadway. (4) the influence of the length of bolt, the distance between rows, the angle of the bolt, the magnitude of pretension force on the support effect by FLAC3D numerical simulation software. The results show that increasing the length of anchor rod can effectively spread the pretightening force to the deep surrounding rock, and the main area of compressive stress is within 1 / 2 of the length of anchor rod. The reduction of the row distance and the angle between the anchors can make the interaction between the anchors superimposed to form a whole compression zone, which can strengthen the surrounding rock as a whole. With the increase of anchor prestress, the strength and range of compressive stress produced by anchor group in surrounding rock are increased, and the maximum principal stress of anchor is 0.02MPa when the pre-tension force of anchor rod is 50KN. The maximum principal stress of 200KN increases to 0.09 MPA. (5) aiming at the characteristics of deformation and failure of large section roadway in Nalinghe coal mine and the deficiency of existing supporting scheme, the combined support scheme of anchor, mesh and cable is put forward and applied in the field. The field monitoring results show that the supporting scheme can effectively control the deformation of surrounding rock and the support effect is ideal.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353
本文编号：2348785
[Abstract]:With the expansion of underground mining intensity and scale, the size of roadway is increasing in order to meet the requirements of large-scale mining equipment, transportation and mine ventilation. The increase of roadway size reduces the stability of surrounding rock, which brings new challenge to roadway support. The support of large-section roadway has become a difficult problem to be solved. Based on the support problem of large section roadway in Nalinghe coal mine, the failure mechanism of surrounding rock and the combined support technology of anchor, mesh and cable are studied by means of field investigation, theoretical analysis, numerical simulation and so on. According to the concrete geological conditions and supporting problems of Nalinhe coal mine, the corresponding supporting countermeasures are put forward. The main contents are as follows: (1) the deformation and failure mechanism of large section roadway is analyzed. After the excavation of large section roadway, the three direction stress imbalance of roadway surrounding rock balance is changed into two direction stress, and the stress concentration phenomenon appears in both side of roadway and roof and floor, which results in the decrease of surrounding rock strength of roadway, and finally leads to the deformation and destruction of surrounding rock. (2) the influence of roadway size on roadway stability is analyzed by FLAC3D numerical simulation software. The results show that the larger the roadway area is, the larger the plastic zone of surrounding rock is, and the more the influence of roadway width on roadway stability is, when the roadway width increases from 4m to 6.5m, the maximum displacement of roof increases from 65mm to 85mm. The difficulty of roadway support is increased. (3) the action mechanism of bolting, mesh and cable combined support on large section roadway is analyzed. After roadway support, the action of anchor cable and bolt pre-tightening force can restore the three-way stress state of surrounding rock, control the deformation of surrounding rock effectively, and maintain the stability of roadway surrounding rock. After supporting, the anchor cable can go deep into the surrounding rock of the roof and suspend the rock which may be loosened and ruptured. Because of the large span of the roadway with large section, the anchor cable also plays the role of reducing the span and reducing the settlement of the roof. The bolt of the two sides can strengthen the surface broken coal body, make it form a large anchor body with the deep stable coal body, restrain the deep coal body from breaking off, and effectively control the deformation of the two sides of the roadway. (4) the influence of the length of bolt, the distance between rows, the angle of the bolt, the magnitude of pretension force on the support effect by FLAC3D numerical simulation software. The results show that increasing the length of anchor rod can effectively spread the pretightening force to the deep surrounding rock, and the main area of compressive stress is within 1 / 2 of the length of anchor rod. The reduction of the row distance and the angle between the anchors can make the interaction between the anchors superimposed to form a whole compression zone, which can strengthen the surrounding rock as a whole. With the increase of anchor prestress, the strength and range of compressive stress produced by anchor group in surrounding rock are increased, and the maximum principal stress of anchor is 0.02MPa when the pre-tension force of anchor rod is 50KN. The maximum principal stress of 200KN increases to 0.09 MPA. (5) aiming at the characteristics of deformation and failure of large section roadway in Nalinghe coal mine and the deficiency of existing supporting scheme, the combined support scheme of anchor, mesh and cable is put forward and applied in the field. The field monitoring results show that the supporting scheme can effectively control the deformation of surrounding rock and the support effect is ideal.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353
【参考文献】
相关期刊论文 前2条
1 王建军;锚索支护在井巷支护中的应用[J];矿业安全与环保;2003年S1期
2 李洪鑫;李世民;徐宝;;地下工程锚固支护理论研究之进展[J];四川建筑科学研究;2014年04期
本文编号：2348785
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