某南锚碇沉井基础数值模拟分析  

Numerical Simulation Analysis of a South Anchorage Caisson

作　　者：王正振[1,2] 龚维明[1,2] 戴国亮[1,2] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,江苏南京210096 [2]东南大学土木工程学院,江苏南京210096

出　　处：《南京工程学院学报（自然科学版）》2017年第1期16-22,共7页Journal of Nanjing Institute of Technology(Natural Science Edition)

基　　金：国家自然科学基金项目(51478109);国家"973"计划(2013CB036304);"十二五"交通运输重大科技专项(2011318494160)

摘　　要：以即将开工的某大桥南锚碇沉井为研究对象,利用PLAXIS 3D有限元软件对其进行施工和使用过程中的应力、位移模拟分析,为该沉井的设计提供参考.将模拟结果与南京长江四桥北锚碇沉井的实测结果进行对比,验证模拟结果的可靠性.模拟结果表明:该沉井施工运营阶段最大竖向位移为35.66cm,最大水平位移为25.28cm,整个沉井在填充内腔、浇筑顶板和锚碇过程中会出现明显倾斜,应对沉井后部土体进行加固处理;整个沉井除混凝土最大主拉应力已超过C30混凝土的轴心抗拉强度设计值之外,其余应力指标均满足设计要求.Based on a bridge program which is going to be started, the stress and displacement during the construction and usage stages of a super-large caisson were simulated by using PLAXIS 3D so as to cast light on the design of this caisson. The results were compared with those measured in the north anchorage caisson of the Fourth Nanjing Yangtze River Bridge to verify the validity of the simulation, indicating that the caisson maximum vertical displacement is 35. 66 cm and the maximum horizontal displacement is 25. 28 cm. Besides, the caisson foundation will incline significantly during the process of filling a cavity, pouring a roof and anchoring, if any other actions are not taken. To avoid such inclinations, the soils in the back of the caisson should be reinforced. All the stress indexes of concrete structure and steel shell should meet the design requirements except the maximum principal tensile stress of concrete which exceeds the designed value of tensile stress of C 30 concrete.

关 键 词：超大沉井 数值模拟 应力 位移 

分 类 号：U443[建筑科学—桥梁与隧道工程]