水锤作用下饱和地基蓄排水隧道的动力响应  

Dynamic response of storage and drainage tunnel in saturated ground under water hammer

作　　者：黄超 钱建固[1,2,3] HUANG Chao;QIAN Jian-gu(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;College of Architecture and Civil Engineering,Xinjiang University,Urumqi,Xinjiang 830047,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学土木工程防灾减灾全国重点实验室,上海200092 [3]新疆大学建筑工程学院,新疆乌鲁木齐830047

出　　处：《岩土力学》2024年第12期3802-3814,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52178345)。

摘　　要：针对饱和土地基中深埋蓄排水隧道在水锤作用下的三维动力响应问题,建立了流体-衬砌-饱和土地基系统的频域有限元与边界元耦合模型。隧道内流体视为无黏性、微可压缩性流体,将隧道衬砌结构模拟为弹性介质,用弹性多孔介质模拟饱和土地基。采用频域有限元法分别求解隧道内流体和衬砌的动力控制方程;采用频域边界元方法求解饱和土地基的动力控制方程。基于流体-衬砌接触面和衬砌-饱和土地基接触面的位移一致、面力平衡及完全不透水边界条件,实现了频域有限元与边界元模型的耦合求解。与以往研究的对比验证了新建模型的正确性。利用该模型计算了蓄排水隧道在水锤作用下的内水压(水锤荷载)和周边饱和土体的位移及孔隙水压力响应。结果表明:(1)水锤作用下的动力响应呈现出显著的周期性和衰减性;(2)土体径向位移幅值显著大于轴向位移幅值;(3)将地基简化为单相弹性介质会导致动力响应评估不准确;(4)水锤作用会对隧道周边广大的区域内造成显著的影响;(5)土体的渗透性越差,隧道内流体压力、土体位移和孔隙水压力的峰值越小。To investigate the three-dimensional dynamic response of a deeply buried storage and drainage tunnel in saturated soil subjected to water hammer,we propose a frequency-domain finite element method and boundary element method(FEM-BEM)coupling model for the fluid-lining-saturated soil system.The fluid is modeled as an inviscid and compressible fluid,the lining as an elastic medium conceptualized as a hollow cylinder of finite length,and the soil as a saturated poroelastic medium.Initially,the governing equations for the fluid and lining are solved using FEM in the frequency domain,while those for the soil are solved using BEM in the same domain.In the following,fluid,lining,and soil are coupled based on the conditions of deformation compatibility,force equilibrium,and impermeable boundary conditions at their interfaces.The presented model is verified through the comparison with the existing models.Finally,a case study of internal water pressure(water-hammer load)and the displacement and pore pressure of the saturated soil in a fluid-filled lined tunnel due to water hammer is presented.The results show that:(1)The dynamic response caused by the water hammer presents significant periodicity and attenuation.(2)The radial displacement of soil is significantly larger than that of axial displacement.(3)Modeling soil as a single-phase elastic medium inaccurately evaluates the dynamic response.(4)The water hammer makes an extensive impact on the ground surrounding the storage and drainage tunnel.(5)The peak values of internal fluid pressure,the soil displacement and pore pressure decrease with the decrease of soil permeability.

关 键 词：水锤 蓄排水隧道 有限元-边界元 饱和土 动力响应 

分 类 号：TU435[建筑科学—岩土工程]