城市硬岩下地铁隧道管片壁后注浆隔振优化分析

Optimization analysis of grouting vibration isolation behind subway tunnel segments under urban hard rock

为了研究硬岩地层叠落隧道管片壁后注浆隔振处理措施,并为隔振材料研究提供基础。结合工程实际,将注浆隔振等效为注浆阻尼,采用有限元模拟分析法,研究隧道管片壁后注浆层不同阻尼比对地铁列车振动荷载的隔振效果影响。研究结果表明:当注浆层阻尼比从0.05增大到0.50,隧道结构上的最大竖向加速度变化率达到14.6%,周边岩土体的变化率达到了60.3%;由于加速度随阻尼比改变的变化率逐步降低,当阻尼比到达0.50时,此改变效果已经达到影响极限的80%,故可以将注浆层阻尼比控制在0.50以内,以达到最大的优化效率及经济效益。

In order to study the treatment measures of vibration isolation after grouting in hard rock strata stacked tunnel segment wall and provide the basis for the research of vibration isolation materials.Utilizing the finite element simulation analysis method,we investigated the influence of varying damping values of the grouting layer behind the tunnel segment wall on mitigating the vibration effects caused by subway train movement.The findings revealed that as the damping ratio of the grouting layer escalated from 0.05 to 0.50,the maximum vertical acceleration change rate on the tunnel structure registered at 14.6%,with a corresponding 60.3%alteration in the surrounding rock and soil.The acceleration change rate diminished progressively with increasing damping ratio;When the damping ratio attains 0.50,this alteration effect had already achieved 80%of its potential impact.Maintaining the damping ratio for the grouting layer below O.50 was advocated to optimize efficiency and economic viability.