老混凝土坝防渗加固施工中温度应力仿真分析

运用大型通用有限元分析软件ANSYS对某老混凝土重力坝防渗加固形成防渗心墙施工中的温度场及温度应力进行全过程的仿真分析.计算中考虑了水温、气温、坝体材料分区、坝体切槽、浇筑层尺寸以及混凝土发热率等因素的影响.得出了施工过程中温度场及温度应力的变化规律,新浇混凝土对坝体整体湿度场影响较小,但浇筑坝内的温度和应力都有一定变化,新老混凝土接触处应力发生较大变化,开挖、浇筑施工中温度作用不显著改变坝体整体应力状态,但温度荷载却为产生坝体应力的主要因素.

Numerical simulation of thermal stress during construction period of seepage control and reinforcement of aged concrete dams

A numerical simulation of temperature field and thermal stress was carried out for the full process of water-tight core wall construction for reinforcement of an aged concrete dam by use of the universal finite element software ANSYS.The influences of some factors,including the water temperature,air temperature,partitioning of dam body materials,size of concrete lift,and rate of heat generation,were taken into account in the calculation,and the regularities of temperature field and thermal stress during the construction were obtained.The newly poured concrete has little influence on the temperature field of the whole dam body;however,it results in local variation of temperature and stress in the newly poured concrete block,and the stress in the interface of old and newly poured concrete changes a lot.It is also indicated that the temperature variation has little influence on the stress of the whole dam body during the excavation and concrete pouring process,but the thermal load is the main factor causing the dam stress.