饱和地基中劲芯水泥土墙隔振的二维BEM-FEM耦合分析  

Coupled 2D BEM-FEM analysis of SDCM wall as wave barrier to isolate ground vibrations in saturated soil

作　　者：孙立光 朱颖 时刚[2] 王瑜 刘攀 郜新军[2] 朱超杰 SUN Liguang;ZHU Ying;SHI Gang;WANG Yu;LIU Pan;GAO Xinjun;ZHU Chaojie(Zhengzhou Metro Group Co.,Ltd.,Zhengzhou 450000,China;School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China;China Railway Tunnel Group No.2 Engineering Co.,Ltd.,Langfang 065000,China)

机构地区：[1]郑州地铁集团有限公司,河南郑州450000 [2]郑州大学土木工程学院,郑州450001 [3]中铁隧道集团二处有限公司,河北廊坊065000

出　　处：《世界地震工程》2024年第4期164-178,共15页World Earthquake Engineering

基　　金：国家自然科学基金资助项目(52078469)。

摘　　要：振动污染在国际上已被列入“七大环境公害”之一,填充沟是振动污染治理的一种常用隔振屏障。传统的填充沟受工程造价和施工工艺等限制工程中应用较困难;为克服上述问题,提出一种新型隔振屏障-内插预制芯墙的劲芯水泥土墙。对于饱和地基中劲芯水泥土墙的隔振问题,饱和地基采用饱和土半解析边界元法(boundary element method,BEM)建模,劲芯水泥土墙采用有限元法(finite element method,FEM)建模,根据饱和地基-水泥土墙交界面的平衡和连续性条件,分别建立了劲芯水泥土墙对入射Rayleigh波(瑞利波)的远场被动隔振和对动力机器基础振动近场主动隔振的半解析BEM-FEM耦合分析方法,并对劲芯水泥土墙的隔振效果进行了计算分析。研究结果表明:饱和地基中设置劲芯水泥土墙能够起到较好的隔振作用,其隔振效果与混凝土墙基本相当且远优于纯水泥土墙;预制芯墙在劲芯水泥土墙隔振系统中起关键作用,为避免弹性波从芯墙底绕射而降低隔振效果,预制芯墙深度应与水泥土墙深度保持一致;增大芯墙厚度对隔振效果提升不大。在等深芯墙条件下,增大墙深能显著提高远场隔振效果,但对近场隔振效果提升较小;增大墙厚也可提高隔振效果,但提高幅度不大。实际工程中,建议结合工程造价和施工工艺,选择合适的水泥土墙和预制芯墙墙厚。此外,屏障距振源距离对主动隔振效果影响较小,建议根据被保护建筑与振源之间的实际情况,选择合适位置构建隔振屏障。Vibration pollution has been listed as one of the“seven major environmental hazards”in the world,which can be eliminated or prevented by using in-filled trench.Traditional in-filled trenches are less commonly used in engineering due to the limitations such as project cost and construction technology.To overcome these problems,this paper proposes a new type of wave barrier-stiffened deep cement mixing wall(SDCM wall)and investigates the vibration isolation effectiveness of SDCM wall in saturated foundation.The analysis was accomplished with the aid of semi-analytic(boundary element method,BEM)coupled with(finite element method,FEM).Herein,semi-analytical BEM was used to model saturated foundation and FEM was used to model SDCM wall.Based on equilibrium and compatibility conditions of contact surface between saturated foundation and SDCM wall,coupled BEM-FEM equations for far-field passive vibration isolation and near-field active vibration isolation of SDCM wall are established,respectively.Effects of the relevant parameters on the vibration isolation efficiency are analyzed and discussed in detail.The study results show that SDCM wall can effectively isolate ground vibrations caused by incident Rayleigh waves and dynamic machine foundations,respectively,of which the screening effectiveness is basically equivalent to that of concrete wall and far superior to that of deep cement mixing wall.The prefabricated core wall plays a key role in the vibration isolation system of SDCM wall.Further,the depth of core wall should be consistent with that of DCM wall to avoid the decrease of screening efficiency due to the diffraction of elastic waves from the bottom of the core wall,while increasing the thickness of core wall has little effect on improving the vibration isolation effectiveness.When the core wall has the same depth with DCM wall,increasing the depth of SDCM wall can significantly improve the far-field isolation effectiveness.but has little effect on improving the near-field isolation effectiveness.Increasing

关 键 词：环境振动 饱和地基 劲芯水泥土搅拌墙 隔振效果 BEM-FEM耦合方法 

分 类 号：TU435[建筑科学—岩土工程]