屏障填充材料对地基振动隔振效果的数值模拟研究

Numerical Research on the Ground Vibration Isolation Effects via Different Barrier Materials

摘要: 强夯是高速公路工程中常用的地基加固技术，然而强夯对周围结构产生的振动影响，严重制约了强夯技术的工程应用。本文采用数值模拟的方法，分析了气垫和泡沫轻质土的隔振效果，优化了两种隔振材料的技术参数。气垫、泡沫轻质土的隔振数值模拟表明，振动频率为20 Hz和10 Hz时，隔振深度为6 m和9 m，两种材料到达最佳隔振效果。考虑到强夯特征振频，优选振动频率为10 Hz，隔振深度为9 m。在10 Hz振频和9 m埋深下，两种隔振材料的水平隔振效率分别为73%、39%，竖向隔振效率分别为68%、35%。气垫隔振材料的弹性模量(即气压)对于隔振效率基本没有影响；泡沫轻质土的密度、弹性模量对隔振效率具有较显著的影响。

Abstract: Dynamic compaction technology is a common technique of foundation reinforcement in highway engineering. However, the adverse effect of dynamic compaction on the surrounding structure se-riously restricts the application of dynamic compaction technology. In this paper, numerical sim-ulation method was used to analyze the vibration isolation effect of air cushion and lightweight treated soil, and optimized the technical parameters of the two kinds of vibration isolation mate-rials. Numerical simulation showed that the optimum vibration isolation depths of these two ma-terials were 6 m and 9 m for vibration frequency of 20 Hz and 10 Hz. Considering the dynamic compaction with the characteristic frequency of 10 Hz, the suggested vibration isolation depth was 9 m. The vibration isolation efficiencies of the two vibration isolation materials were 73% and 39% in the horizontal direction, and 68% and 35% in the vertical direction, respectively. The elastic modulus of air cushion had minor effect on the vibration isolation efficiency. The density and elastic modulus of lightweight treated soil had significant impacts on the vibration isolation efficiency.