溪洛渡电站地下洞室群爆破地震效应的研究

 采用现场爆破振动测试研究复杂地下导流洞群爆破地震波传播规律，并利用萨道夫斯基经验公式对测试数据进行回归分析，测试结果表明水平向爆破质点峰值振动速度可以作为地下洞室的安全判据；应用FLAC3D数值软件模拟爆破振动对相邻洞室的影响，得到爆破振动作用下相邻洞室振动速度、应力和位移的分布规律，并从静载作用和动载作用两方面分析评价相邻洞室的安全稳定性。计算结果表明：现场测试结果与计算结果吻合较好；采用振动速度作为安全判据是可行的；爆破振动作用下相邻洞室迎爆侧是容易出现破坏的区域，且随着冲击荷载增大，迎爆侧直墙最容易出现拉伸破坏。最后针对具体工程，根据相邻洞室洞壁最大拉应力与最大振动速度的统计关系，并结合岩石动态抗拉强度准则提出爆破振动作用下相邻洞室发生破坏的临界振动速度。

STUDY OF BLASTING SEISMIC EFFECTS OF UNDERGROUND CHAMBER GROUP IN XILUODU HYDROPOWER STATION

Based on field testing of blasting vibration,the blasting seismic wave propagation laws in underground diversion tunnels under complicated construction conditions are studied. Regression analysis of testing data is conducted according to Sadaovsky empirical formula and the field testing results indicate that horizontal particle peak velocity of blasting vibration can be taken as safety criterion for underground chambers. The numerical simulation is carried out to study the influence of blasting vibration on adjacent diversion tunnels by software the fast Lagrangian analysis of continua in 3D(FLAC~(3D)) and distributions of particle vibration velocity,stress and displacement of the adjacent diversion tunnel wall are obtained. The stability of adjacent chamber is assessed by considering the effect of static load and dynamic load separately. The result of numerical simulation shows that the blasting vibration responses predicted by numerical simulation agree well with field testing;and it is reasonable to use blasting vibration velocity as safety criterion. The near-blasting side of adjacent tunnel is the area where failure tends to occur under blasting load;and the tensile failure will appear possibly in adjacent tunnel straight wall facing blasting with the blasting impact load increasing. Finally,the critical vibration velocity of adjacent chamber under blasting vibration is proposed according to the statistical relationship between maximum tensile stress and maximum vibration velocity combined with the dynamic tensile strength criteria of rock for a project.