冲击地压下锚杆作用机理研究.doc

太原理工大学工程硕士研究生学位论文 PAGE PAGE VI 冲击地压下锚杆作用机理研究 摘 要 当巷道发生冲击地压时，锚杆支护可以起到减少冲击灾害的作用。本文应用数值模拟方法，基于现行冲击地压机理和控制技术，对冲击地压下巷道围岩动力响应规律和锚杆支护的减灾作用进行研究；然后通过9次正交数值模拟试验，分析冲击地压下影响巷道锚杆支护效果的关键因素，并进行支护参数优化；最后分析了锚杆预紧力对冲击地压下巷道支护效果的影响。 论文获得以下主要结论： （1）在冲击过程中，顶板拉应力和拉应力深度不断变大，两帮围岩加速度波形呈“正弦”波形，巷道稳定性变差。 （2）锚杆支护可以有效控制顶板和两帮围岩（特别是两帮）的拉应力大小和深度，在冲击过程中起到较好的支护作用。锚杆对围岩的支护作用实际上是通过改善围岩应力状态及分布来实现的，而不是通过控制位移来实现。 （3）冲击过程中，锚杆最大拉力的位置有向锚杆中间移动的趋势，且锚杆拉力始终呈现两端小、中间大的规律。 （4）冲击地压下，锚杆间距是影响锚杆支护效果的关键因素。在一定范围内，提高锚杆预紧力是一项有效的防冲措施。 关键词：冲击地压；锚杆支护；预紧力；减灾作用；数值模拟；  mechanism of Bolt action on rock-burst ABSTRACT When the rock-burst occurs in roadway, bolting can play a role in reducing the impact of disasters. In this paper, numerical simulation method, based on the current mechanism and control technology of rock-burst, is used to study the dynamic response of roadway and mitigation effects of bolting in the rock-burst; then nine orthogonal numerical simulation tests are conducted to analyze the key factor of the bolting effect in rock-burst, and to optimize support parameters; finally the influence of the bolt pretightening force on roadway supporting effect is analyzed. This paper obtains the following conclusions: （1）During the impact, roof tensile stress and depth of tensile stress become larger and larger, and the acceleration waveform of coal wall is sine wave,roadway stability becomes poor. （2）Bolt can effectively help control the tensile stress and its depth of the roof and coal wall (especially coal wall),plays a good role in supporting during the impact. The role of bolt is achieved by improving the rock stress condition and distribution actually, rather than by controlling displacement of rock. （3）During the impact, the position of maximum tension in bolt has the trend of moving to the middle of bolt, and bolt tension always shows the rule : Small at both ends, large in the middle. （4）In rock-burst, bolt spacing is the key factor of bolting effect. Within a certain range, improving pretightening force of bolt