柔性泡沫对振杆密实法模型试验边界效应的影响分析  

Analysis on influence of flexible foam on boundary effects in model tests of vibratory probe compaction method

作　　者：庄仲旬 杜广印[1,2] 刘松玉[1,2] 齐睿典 唐紫琼 Zhuang Zhongxun;Du Guangyin;Liu Songyu;Qi Ruidian;Tang Ziqiong(School of Transportation,Southeast University,Nanjing 211189,China;Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学交通学院,南京211189 [2]东南大学江苏省城市地下工程与环境安全重点实验室,南京211189

出　　处：《东南大学学报（自然科学版）》2023年第4期600-608,共9页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(42277153,41977241);江苏省交通科技资助项目(2022G1-2);江苏省交通科技与成果转化资助项目(2021G31-2).

摘　　要：为研究柔性泡沫材料对刚性模型箱边界效应的改善效果,在模型箱侧壁分别内衬了聚氨酯、聚苯乙烯和珍珠棉3种泡沫,开展了振杆密实法处理可液化地基的室内模型试验.采用2-范数偏差法对振动加速度场进行分析,通过将加速度时程信号功率谱密度对频率进行积分处理,估算出边界材料耗散的能量.结果表明,聚氨酯泡沫吸收和散射的能量约为输入水平的53.9%,其对刚性模型箱边界效应的改善作用优于聚苯乙烯泡沫和珍珠棉泡沫.柔性泡沫主要通过减少弹性波向模型土层中的反射来减弱模型箱的边界效应.泡沫材料与土体的波阻抗越接近,减少弹性波反射的能力越强.To investigate the influence of flexible foam on the boundary effect of a rigid model box,polyurethane foam,polystyrene foam,and expanded polyethylene foam were lined the on the side wall of the model box.Model tests were conducted to examine the improvement of liquefiable foundation by the vibratory probe compaction method.The 2-norm deviation method was used to analyze the vibration acceleration field,and the energy dissipated by the boundary material was quantified by integrating the power spectral density of the time acceleration histories with respect to the frequency.The results demonstrate that polyurethane foam absorbs and scatters approximately 53.9%of the input energy level,and its effectiveness in reducing the boundary effect of rigid model box surpasses that of expanded polystyrene foam and expanded polyethylene foam.Flexible foams mitigate the boundary effect of rigid model box by minimizing the reflection of elastic waves within the soil.The closer the wave impedance of the foam is to that of the soil,the stronger the ability to reduce the reflection of elastic waves is.

关 键 词：边界效应 振杆密实法 模型试验 边界材料 振动加速度 

分 类 号：TU43[建筑科学—岩土工程]