基于ANSYS的地铁车站大体积混凝土侧墙裂纹机理分析  

Research on Crack and Temperature Stress of Mass Concrete Side Wall of Subway Station Based on ANSYS

作　　者：陈得良[1] 朱梓铭 陈昌萍 CHEN Deliang;ZHU Ziming;CHEN Changping(College of Civil Engineering,Changsha University of Science and Technology,Changsha 410076,China;College of Civil Engineering and Architecture,Xiamen University of Technology,Xiamen 361000,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410076 [2]厦门理工学院土木工程与建筑学院,福建厦门361000

出　　处：《湖南科技大学学报（自然科学版）》2022年第1期24-30,共7页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(51778551)。

摘　　要：针对地铁车站大体积混凝土侧墙施工中出现的裂纹问题,借助有限元软件,对大体积混凝土侧墙进行了温度应力分析,并探讨了裂纹成因与规律.在考虑新老混凝土界面层热膨胀率变化的基础上,利用弹簧单元模拟了混凝土侧墙边界上的约束作用,并通过选取不同的边界约束强度和温度荷载等参数,对混凝土侧墙温度应力进行了参数化分析.研究结果表明:侧墙的温度应力分布规律能较好地反映厦门地铁站侧墙的裂纹分布规律和成因,侧墙端部的裂缝与温度作用下侧墙端部较大的剪应力或第一主应力有关,侧墙中部的竖直裂缝与温度作用下侧墙中部较大的X方向正拉应力有关.适当增强侧墙与地连墙的约束强度,同时减弱侧墙与底部基础间的约束作用,对控制侧墙底部裂缝的发展较为有利.侧墙与地连墙间后浇筑混凝土产生的水化热减缓了侧墙的降温收缩,能适当降低侧墙底部的拉应力.Aming at cracks in the construction of mass concrete side walls of the subway station, the thermal stress analysis of the mass concrete side wall of subway station is carried out with finite element software, and the causes and laws of the cracks are discussed. On the basis of considering the change of thermal expansion rate between new and old concrete interfacial layers, the restraint effect on the boundary of concrete side wall is simulated with spring element, and the temperature stress of concrete side wall is parameterized and analysed by selecting different parameters, such as boundary restraint strength and temperature load. Results show that the temperature stress distribution law of the side wall can well reflect the crack distribution law and cause of the side wall of Xiamen metro station. The cracks at the end of the side wall are related to the larger shear stress or the first principal stress at the end of the side wall under the action of temperature. The vertical crack in the middle of the side wall is related to the larger X-direction normal tensile stress in the middle of the side wall under the action of temperature. It is beneficial to control the development of cracks at the bottom of the side wall by appropriately enhancing the restraint strength of the side wall and the diaphragm wall and weakening the restraint between the side wall and the bottom foundation. The hydration heat generated by pouring concrete between the side wall and the ground connecting wall slows down the cooling shrinkage of the side wall and can appropriately reduce the tensile stress at the bottom of the side wall.

关 键 词：大体积混凝土 新老混凝土界面 侧墙 有限元 温度应力 裂纹 

分 类 号：TU375.401[建筑科学—结构工程]