金川二矿区深部巷道支护机理研究以及围岩稳定性的数值模拟

【作者】 李宏业；

【导师】 吴爱祥； 王永前；

【作者基本信息】 中南大学 ， 采矿工程， 2003， 硕士

【摘要】 与国内外许多矿山相比，金川镍矿具有深、大、富、碎等特点，因而，从矿山一投产就开始了科研攻关。在巷道支护方面，尤其投入了不少物力和人力，也取得了丰硕的成果，如近些年来一直指导金川巷道施工的“先柔后刚，先让后抗”的支护原则，并在金川二矿区二期工程的建设中发挥了重要的作用。锚杆支护技术的引进以及在工程中的探索和逐步的推广使用，彻底改变了传统的支护理念，即支护就是要靠外部支架去支撑围岩的变形，形成了以强化巷道周边围岩破碎后的残余强度，提高围岩自撑能力的支护理念。 近年来，随着开采深度的逐渐增加，巷道支护的问题又越来越突出。原来使用比较普遍的锚杆支护、U型钢拱架支护以及喷射混凝土支护在1000m(埋藏深度约760m)开拓工程的施工过程中出现了严重的破坏，巷道变形速度之快、变形量之大，二矿区历史上从未有过。 巷道的支护有其最佳的支护方式、最佳的支护强度，这根据巷道所处的地质环境和人们对巷道工程本身的要求不同而不同。“先柔后刚，先让后抗”的支护原则，似乎限制了人们思想，解决巷道支护的问题就是要分两步骤支护，且选择二次支护的时间是关系到支护成败的关键。但很少提出过“先柔”要柔到什么程度，“后刚”要刚到什么程度，以及“先让”要让到什么程度，“后抗”要抗到什么程度，对支护强度的合理范围并没有过多的探究。 论文结合《金川二矿区深部巷道支护机理的研究以及围岩稳定性的数值模拟》课题，针对金川二矿区开采深度日益增加而所引起的严重的巷道支护问题，对金川二矿区地质条件以及以往的岩石力学性质的测定结果、金川二矿区深部岩体以及巷道的变形特征、巷道支护的失效形式、金川二矿区锚杆支护的支护能力以及巷道支护的机理等展开了研究，并运用ANSYS有限元软件对1150水平运输巷道的返修方案进行了模拟计算。论文的主要研究工作如下： (1)对国内外有关巷道支护的技术发展和理论研究进行了研究，包括U型钢、锚杆支护、锚索支护、喷射混凝土支护以及其它的支护方式。 (2)对金川二矿区的地质条件、地应力随深度变化的规律以及以往的关于岩体的力学特性测试的结果进行了全面的调查和研究，认为金川二矿区的岩石单体强度较高，岩体的整体强度低，且具有明显的流变性，具有软中南大学硕十学位论文岩的特征。. (3)对巷道围岩变形与支护阻力之间的关系进行了研究，给出了巷道支护的最佳工作阻力围0.2一0.3MPa。分析了U型钢拱架承载能力和支护阻力，认为钢拱架的实际支撑能力远未达到理论极限值的原因是实际支护工作中支架受偏心载荷。对锚杆支护作用方式和支护能力的计算得出，金川二矿一区锚杆的托板的托锚能力与锚杆的锚固能力不足而且不匹配，推导出金川二矿区锚杆锚固力估算公式:锚杆的最大锚固力的是最大拉拔力的75%(，并对喷射混凝土支护的变形机理等进行了研究。 (4)分析了金川二矿区深部高应力碎胀岩体的碎胀和时效性以及巷道的变形特征，研究了巷道深部围岩的变形规律以及锚杆支护巷道支护破坏失效形式，从而印证了锚杆支护托锚能力与锚杆粘锚能力的不足和相互的不匹配，提出了强初撑急增阻高阻力锚杆支护是解决金川二矿区支护问题的有效途径‘， (5)运用ANSYS超巨型有限元程序在弹塑性理论的基础上对金川.二矿区1150水平运输巷道的几种返修方案进行了模拟计算和评价。 (6)对金川二矿区深部巷道围岩变形的基本特征形成了基本的认识，提出围岩维护的基本原则是:在变形地压中，围岩与支护是相互影响共同作用的共同结构体，维护的着眼点在于充分利用和发挥围岩的自撑能力上。井给出了几点合理的巷道地压控制措施。更多还原

【Abstract】 Compared with many mines in china and other countries, Jinchuan nickel mine has such characters as ’deep, large , rich and fragmentized’. Once production began, studies about it were started. Especially there were much work have been done on the roadway’s support and a great of achievements have been got. For example, the principle of carrying out the soft way before stiff way, and making some sidestep before support, which have been directed the roadway’s support and have made a important role in 2nd construction of Jinchuan mine. It is completely changed the idea of traditional support that the deformation of the roadway being restrained by eyeframe, since the bolt was introduced, studied as well as popularized. As a result, the idea that strengthening the retained strength of surrounding rock mass so as to improve the self-supporting capacity has been formed.With the increasing of mining depth in recent years, the problem of roadway’s support in Jinchuan nickel mine become more and more serious. The traditional ways of bolt and U-formed arched falsework have been destroyed badly in the roadways of 1000m level. It is the first time that the roadway deformation’s rate is so quick and the deformation is so large.According to the geological environment and the demand, there exist best roadway’s support way and most reasonable intensity. It seems that man’s idea about support has been restrained by previous principle, that support must be divided into two steps, and the time is crucial to the 2nd support. But none points out how great the degree of the first soft way and lately stiff way is, what the reasonable range of the support intensity is.Combining with the project that study on roadway’s support mechanism in Jinchuan deep mine and simulation of the surrounding rock mass’s stability, aiming at the serious problems of the roadway’s support, studies have been done in the thesis as follows: the geological condition and the former test results about the rock in Jinchuan mine; the characters of the deformation of the rock mass and roadway; the forms of the support invalidation; the capacity of the bolt support in Jinchuan 2nd mine and the mechanism of the support. The blue print of reparation in the 1150m level of Jinchuan 2nd mine have been analyzed with the ANSYS .The followingare main researches:(1) The theories and technology about roadway’s support in china and other countries are studied, which include the U-formed arched falsework, bolt, cable anchor, shotcrete lining and others.(2) The geological condition, the law of stress changing and the test results of the rock mass’ mechanics characters are investigated and researched. The author argues that the strength of the rock is low and rock mass’ is high, and rock mass can creep. Those are the characters of soft rock.(3)The relationship between deformation of the surrounding rock mass and resistance of the support is studied. The reasonable range (0.2~0.3MPa) of the support is given. After analyzing the bearing capacity and the supporting performance of the U-formed arched falsework, the reason that the actual supporting capacity not reaching the theoretical limit value is the stress is eccentric. According to the analysis about the bearing way and calculation of the bearing capacity of the bolt, both the splint and the bolt have not enough capacities and they are not matching. The estimate bearing capacity of the bolt is given. That is the anchoring force is just about 75% of the drawing force of the bolt test. The deformation mechanism of the shotcrete is studied.(4) The expansion on breaking, time effect and the characters of roadway’s deformation are analyzed. The law of the deformation of the roadway’s surrounding rock mass and several forms of bolt becoming invalid are researched. So the result of the capacity of the splint and the bolt is not enough and they are not matching are verified. A support system of strong in initial and steep increasing resistance and high bearing capacity is put forward. It is the effective way to r更多还原