水工隧洞设置减震层作用机理与效果分析

发布时间：2018-01-23 08:32

本文关键词： 水工隧洞减震层作用机理变形传递系数减震效果减震材料　出处：《水力发电》2017年12期 　论文类型：期刊论文

【摘要】：基于水工隧洞围岩、减震层和衬砌的横向作用机制和振动理论,将水工隧洞围岩、减震层和衬砌简化为三自由度振动体系,并推导其运动方程,求解变形传递系数,探讨减震层与围岩刚度比、地震波荷载与结构自振频率比对水工隧洞抗减震特性的影响。在此基础上,分析了不同减震材料参数、不同减震层厚度对水工隧洞地震响应的影响。计算表明:在低频条件下,减小刚度比能够有效降低结构地震响应,在高频条件下,减震效果不明显;设置减震层能够有效缓解衬砌结构受力变形状态,且减震层弹性模量与围岩相差越大时,减震效果越明显;增大减震层厚度能有效减小衬砌结构应力和变形,但减震层厚度超过0.2 m,衬砌受力变化逐渐减缓。
[Abstract]:Based on the lateral action mechanism and vibration theory of surrounding rock, damping layer and lining of hydraulic tunnel, the surrounding rock, damping layer and lining of hydraulic tunnel are simplified as three degrees of freedom vibration system, and their motion equations are deduced. The effects of the ratio of seismic wave load to surrounding rock stiffness, the ratio of seismic wave load to the natural vibration frequency of the structure on the anti-vibration characteristics of hydraulic tunnel are discussed. On the basis of this, the parameters of different damping materials are analyzed. The effect of different thickness of damping layer on the seismic response of hydraulic tunnel is calculated. The results show that reducing the stiffness ratio can effectively reduce the seismic response of the structure under the low frequency condition, but the effect is not obvious at the high frequency condition. Setting the damping layer can effectively alleviate the deformation state of the lining structure, and the bigger the difference between the elastic modulus of the damping layer and the surrounding rock is, the more obvious the damping effect is. Increasing the thickness of the damping layer can effectively reduce the stress and deformation of the lining structure, but the thickness of the damping layer is more than 0.2 m, and the change of the lining force gradually slows down.
【作者单位】：江西省交通科学研究院;江西农业大学;
【基金】：江西省交通运输厅科技项目(2017R0026、2015C0018、2015C0019、2016H0024、2016H0025)
【分类号】：TV554
【正文快照】： 0引言水工隧洞的力学作用机制及其所处的地形地质条件均较为复杂,在地震作用下易发生失稳破坏,给工程稳定带来极大挑战,从而需要研究水工隧洞的减震作用机理,并在此基础上提出合理有效的减震措施。设置减震层是工程实践中较为常用的减震措施,减震层将衬砌与围岩隔开,从而减小

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