巷道吸能支护的减震防冲效应分析

ANALYSIS OF SHOCK ABSORPTION AND ANTI-IMPACT EFFECT OF ENERGY-ABSORBING SUPPORT IN ROADWAY

冲击地压是煤矿开采的主要动力灾害,巷道吸能支护是防御冲击地压灾害的新型支护方式和有效手段。吸能支护是在刚性支护基础上附加阻尼耗能构件形成的巷道支护,基于巷道顶板与支护相互作用的动力学模型,分析了在巷道刚性支护与吸能支护作用下的顶板-支护系统动力响应,同时就阻尼构件在吸能支护上的分布特征对减震防冲效应的影响进行了分析,研究了阻尼构件在支护中的串联、并联、混联3种分布特征下的支护吸能减震防冲效应。结果表明:相比于刚性支护,吸能支护不仅能有效抑制顶板的冲击响应,还对支护体的冲击响应具有自保护能力;串联吸能支护模式与混联吸能支护模式对顶板冲击位移的控制及支护体加速度的抑制作用相当,且均优于并联吸能支护模式,其中,在串联吸能支护模式下,顶板冲击位移可下降约89%,支护体加速度可下降约55%。进一步优化串联吸能支护模式可知,当采用支护体上端串联布置吸能构件时,构件吸能效果发挥的最好,并且支护体的变形、应力、等效塑性应变变化平稳且幅值较小,同时相比于在下端以及两端串联吸能构件时支护等效塑性应变分别下降约77%和96%。该研究为冲击地压动力灾害的防冲吸能支护动力可靠性设计提供思路。

Rock burst is the main dynamic disaster of coal mining,the energy-absorbing support in roadway is a new support method and effective means to prevent rock burst disasters.The energy-absorbing support is a kind of roadway support formed by adding damping energy dissipation components up rigid supports.Based on the dynamic model of interaction between roadway roof and support,the dynamic response of the roof-support system with roadway rigid support and energy-absorbing support is analyzed,the influence of distributed characteristics of damping components on the effect of shock absorption and anti-impact is investigated,and the effect of energy absorption,shock absorption and anti-impact of damping components in support with series,and parallel as well as hybrid distributed characteristics are studied.The results show that:compared with the rigid support,the energy-absorbing support can effectively suppress the impact response of roof and has self-protection ability to the impact response of support body.The energy-absorbing support with series and hybrid connection have similar control effects on roof impact displacement and acceleration of support body,which are better than the energy-absorbing support with parallel connection.The roof impact displacement decreases by about 89%and the acceleration of support body decreases by about 55%in the energy-absorbing support with series connection.Further optimization of the series mode shows that:when the energy-absorbing components are arranged in series at the upper end of the support,the energy-absorbing effect of the component is the best,the deformation,stress and equivalent plastic strain of support body change smoothly and the amplitude is small,and the equivalent plastic strain of support body decreases by about 77%and 96%respectively compared with that of the lower end and the two ends connected in series.This study provides ideals for the dynamic reliability design of anti-impact and for the energy-absorbing support in the dynamic disaster of rock burst.