深厚软土地区大型沉井突沉行为分析  

Analysis on Sudden Sinking Behaviors of Massive Open Caisson in Deep-thick Soft Clay Area

作　　者：张治成[1] 邓燕羚 郑锋利 王金昌[1] Zhang Zhicheng;Deng Yanling;Zheng Fengli;Wang Jinchang(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,P.R.China;Wenzhou Oujiang River Estuary Bridges Co.,Ltd.,Wenzhou,Zhejiang 325002,P.R.China)

机构地区：[1]浙江大学建筑工程学院,杭州310058 [2]温州瓯江口大桥有限公司,浙江温州325002

出　　处：《地下空间与工程学报》2020年第3期933-943,共11页Chinese Journal of Underground Space and Engineering

摘　　要：为了研究深厚软土地区某大型沉井的突沉行为,结合现场监测数据对沉井的下沉过程及受力特性进行分析,推测了沉井发生大幅度突沉的机理;基于ABAQUS/Explicit有限元软件,将显式动态求解方法应用于沉井下沉的拟静力过程分析,揭示了沉井突沉过程中土体的扰动损伤行为。分析结果表明,由于局部土体损伤失效带动周围大面积土体的不稳定损伤演化从而引发沉井快速下沉,土体损伤耗散能的大小可表征相应的沉井区域的下沉量;采用扩展的Drucker-Prager模型并结合损伤因子演化方程用来模拟土体扰动损伤特性的方法,能够定量分析评价沉井周边软土在受力变形后的扰动度和相应的沉井突沉行为。To study the sudden sinking behaviors of a large open caisson in deep-thick soft soil area,the sinking process and mechanical characteristics of the caisson were analyzed with field monitoring data,and the mechanism of large-scale sudden sinking of the caisson was also deduced.Based on ABAQUS/Explicit finite element software,the explicit dynamic solution method was applied to analyze the pseudo-static process of caisson sinking and to reveal the soil disturbance and damage behaviors of soft soil during the sudden sinking process of caisson.Results show that the rapid subsidence of caisson is caused by the unstable damage evolution of the large area of surrounding soil,which was brought about by damage failure of local soil,and the dissipated energy of soil damage can represent the sinkage of corresponding areas of caisson.The extended Drucker-Prager model combined with the evolution process of damage factor described by displacement,which is used to simulate the damage characteristics of soil disturbance,can quantitatively analyze and evaluate the disturbance degree of soft soil around caisson after forced deformation and the corresponding sudden sinking behaviors of open caisson.

关 键 词：沉井 软土地基 现场监测 突沉行为 土体扰动损伤 扰动度 

分 类 号：U443.13[建筑科学—桥梁与隧道工程]