摘要
通过几何相似比为1∶20的有/无泡沫混凝土减震层的浅埋偏压连拱隧道振动台模型试验,研究了泡沫混凝土减震层对连拱隧道衬砌加速度和应变的影响规律,探讨了泡沫混凝土减震层的减震效果和机理。研究结果表明:泡沫混凝土减震层显著降低了连拱隧道左洞拱顶的加速度响应,却显著增大了右洞拱顶的加速度响应;减震层不改变加速度响应的主要频率区间。泡沫混凝土减震层除对左洞左拱脚和左拱顶水平加速度有减小作用之外,对隧道其余位置测点尤其是右洞具有显著的放大效应,使得偏压侧的水平加速度“临空面效应”显著增加。减震层对左洞竖向加速度主要表现为减小作用,对于右洞除在左右拱脚位置表现为减小作用外,其余位置表现为显著放大,这与隧道偏压的应力环境有关。应严格控制右洞偏压侧上覆岩土层厚度。泡沫混凝土减震层的设置不会改变隧道衬砌测点横截面方向应变显著大于纵向应变的规律;减震层能显著减小横截面方向和纵向应变,但减小效果存在差异。泡沫混凝土减震层对隧道衬砌应变的影响明显不同于对加速度的影响,不存在应变的“临空面效应”的放大作用。除个别位置、个别激振强度外,泡沫混凝土减震层具有显著减小衬砌主应变的效果,存在激振强度越大,应变减小作用越小的规律。地震波在泡沫混凝土减震层内部孔隙中的折射与反射耗散地震能量,减震层的较大变形能力能吸收地震能量,从而使其具有减震效果,但具体减震效果与衬砌位置所处应力环境和地震波传播特性密切相关。
Based on the shaking table model tests of a shallow-buried bias double-arched tunnel with and without foam a concrete damping layer whose geometric similarity ratio is 1:20,the influence of foam concrete damping layer on the acceleration and strain of the tunnel lining is studied,and the seismic reduction effects and mechanism of foam concrete damping layer are discussed.The results show that the damping layer significantly reduces the acceleration response of the left arch of double-arched tunnel,but significantly increases the acceleration response of the right arch.The foam concrete damping layer does not change the main frequency range of acceleration response.In addition to reducing the horizontal acceleration of the left arch foot and left arch crown of the left tunnel,the foam concrete damping layer has a pronounced amplification effect on other measuring points of the tunnel,especially in the right tunnel,leading to a signficantly increase in the'free surface effect'on the biased side.The vertical acceleration of the left tunnel is mainly reduced by the foam concrete damping layer.For the right tunnel,except for the left and right arch feet,the vertical acceleration is reduced,and the other locations are significantly enlarged,which is related to the biased stress environment of the tunnel.The thickness of the overlying rock and soil layer on the eccentric pressure side of the right tunnel should be strictly controlled.The foam concrete damping layer does not change the rule that the strain in the cross section direction of the corresponding position of the tunnel lining is significantly greater than the strain in the longitudinal direction.It can significantly reduce the strain in cross section direction and longitudinal direction,but the reduction effect is different,which is related to the location.The influence of foam concrete damping layer on the strain of tunnel lining is markedly different from that on the acceleration,and there is no amplification of the'free surface effect'of strain.In addition to the individual excitation strength at individual locations,the foam concrete damping layer has the effect of significantly reducing the main strain of the lining.There is a law that the greater the excitation strength,the smaller the strain reduction effect.The refraction and reflection of seismic waves in the pores of the foam concrete damping layer dissipate seismic energy.The larger deformation capacity of the foam concrete damping layer can absorb seismic energy,so that it has a damping effect.However,the specific damping effect is closely related to the stress environment of the lining location and the propagation characteristics of seismic waves.
作者
杨慧
江学良
刘潺
王浩冬
魏珍珍
尹军
汪亦显
YANG Hui;JIANG Xueliang;LIU Chan;WANG Haodong;WEI Zhenzhen;YIN Jun;WANG Yixian(School of Future Transportation,Guangzhou Maritime University,Guangzhou 510725,China;School of Civil Engineering,South Central University of Forestry and Technology,Changsha 410004,China;Dahan Holding Group Shaoyang Real Estate Co.,Ltd.,Shaoyang 422100,China;School of Civil Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《振动工程学报》
北大核心
2026年第1期195-204,共10页
Journal of Vibration Engineering
基金
广东省普通高校重点领域专项(2023ZDZX4044,2023ZDZX4045)
湖南省自然科学基金资助项目(2022JJ31005,2020JJ4944)
广州市教育局“羊城学者”领军人才项目(2024312379)。
关键词
浅埋偏压连拱隧道
泡沫混凝土减震层
振动台试验
减震效果
shallow-buried and bias double-arched tunnel
foam concrete damping layer
shaking table test
seismic reduction effect
