输水隧道的减震措施研究

Study on Shock Absorption Measures of Water-Conveyance Tunnel

隔震技术是近几十年发展起来的新技术,对地面结构减震效果显著。本文运用Newmark隐式时间积分有限元法并采用粘-弹性人工边界,分析了在输水隧道施工中设置减震层和注浆加固一定范围内围岩这2种方法的减震效果、适用条件及其减震机理。计算结果表明:减震层或加固层的设置均使隧道衬砌应力减小,起到保护隧道衬砌的作用;在较大的范围内注浆加固围岩的办法,对软土中的输水隧道的减震更加有效,它能充分发挥围岩的承载能力;而在围岩与衬砌间设置减震层的办法,对稳定性极好的坚硬围岩中的输水隧道的减震效果更加有效。计算结果可为地震区的输水隧道抗震设计提供依据。

Seismic isolation technology is a new method developed in recent decades.It has been applied widely in ground-structures and achieved remarkable efficiencies.Based on Newmark′s step-by-step implicit integration FEM method and viscoelasticity artificial boundary theory,this paper investigated two kinds of shock absorption measures,which are shock absorption layer setting and grouting in the surrounding rock within certain influencing distances to the linings during the construction of water-conveyance tunnel.Moreover,the shock absorption effects,applicability and mechanisms are also analyzed.The results show： in soft soil,the stress in the lining of the water-conveyance tunnel decreases by using of the two measures,which is liable to protect the lining;rock grouting is a more effective shock absorption measure and the aseismatic capability of surrounding rocks can be improved.For water-conveyance tunnel in hard rocks,the shock layer is more effective.The results can provide useful reference for the aseismatic design of water-conveyance tunnel.