吸能支护结构在隧道岩爆灾害防治中的应用研究

Application Research on Energy-Absorbing Support Structure for the Prevention and Control of Tunnel Rock Burst Disasters

为提高隧道岩爆灾害的控制效果,提出钢框架和钢管组合式的吸能支护结构,进一步吸收岩爆产生的动能,拦截飞石,加强围岩及隧道整体结构的稳定性。现场试验结果表明,随着隧道挖掘距离增加,拱顶沉降和拱底隆起位移均呈下降趋势,且采用吸能结构时,拱顶及拱底位移数值均小于锚杆支护结构,利用钢框架和钢管可以提高围岩稳定性、降低岩爆风险。数值模拟分析结果表明,在相同冲击力条件下,钢框架和钢管组合式吸能支护结构的吸能大于锚杆支护,当冲击力为600 kN时,吸能支护结构的吸能高达689 kJ,而锚杆支护的吸能仅为294 kJ。随着冲击力持续时间增加,支护结构变形位移呈递增趋势。当冲击力为200 kN时,支护结构的最大变形位移为14 mm。因此利用钢框架和钢管支护隧道,可以有效防治岩爆灾害,提高围岩稳定性,为隧道安全施工提供技术支持。

In order to improve the control effect of the tunnel rock explosion disaster,steel frame and steel pipe combination of energy-absorbing support structure are proposed to further absorb the kinetic energy generated by the rock explosion,intercept the flying rocks,and strengthen the stability of the surrounding rock and the overall structure of the tunnel.Field test results show that,with the increase of tunnel excavation distance,the settlement of the arch and the displacement of the arch bottom rises are downward trend,and with the use of energy-absorbing structure,the arch top and arch bottom displacement values are smaller than those of the anchor support structure,the use of steel frame and steel pipe can improve the stability of the surrounding rock and reduce the risk of rock explosion.Numerical simulation analysis results show that,under the same impact conditions,the energy absorption of steel frame and steel pipe combined energy-absorbing support structure is greater than that of the anchor support,when the impact force is 600 kN,the energy absorption of the energy-absorbing support structure can reach up to 689 kJ,while the absorption of the anchor support is only 294 kJ.With the increase in the duration of the impact force,the deformation displacement of the support structure is an increasing trend.When the impact force is 200 kN,the maximum deformation displacement of the support structure is 14 mm.Therefore,the use of steel frame and steel pipe support tunnel can effectively prevent and control the rock explosion disaster,improve the stability of the surrounding rock,and provide technical support for the safe construction of the tunnel.