【作者】 王刚；

【导师】 马震岳；

【作者基本信息】 大连理工大学 ， 水利水电工程， 2005， 硕士

【摘要】 随着时间的推移,混凝土大坝会达到甚至超过其使用寿命,这样,就出现了混凝土坝的老化问题。解决坝体老化、混凝土破坏和渗漏严重等问题,对老坝进行改建、扩建和加固,并让其重新焕发青春,是全世界范围内水利工程研究都要面临的一个重要课题。就混凝土坝改建、扩建和加固施工面临的难题而言,关键问题在于新老混凝土结合面的处理和采取有效的温控措施。本文即是以当前提出的一种全新的老坝再生技术(坝体置换混凝土形成防渗芯墙技术)为基础进行研究,以利于工程实际问题的解决。本文的工作是以我国东北某老化混凝土重力坝为研究对象,针对该实际工程的老化现象以及进行坝体再生施工时可能出现的坝体安全性问题进行分析。分析过程将以大型有限元通用软件ANSYS为平台,应用其自带的APDL语言,编写大型施工仿真程序,着重对该大坝典型坝段坝体施工过程进行仿真模拟,并对施工期的温度场、温度应力进行三维有限单元仿真计算。在温度场和温度应力的计算中,将考虑混凝土热学、力学参数随龄期变化,坝体的不同材料分区,坝体不同的分层开挖、浇筑施工的工期和间歇期,以及不同的切槽开挖、浇筑尺寸等对温度场和温度应力的影响。计算成果将给出温度场、温度应力随时间变化的规律以及诸多温控因素对坝体施工温度场和温度应力场的影响程度。依托这种开创性的老化混凝土坝的再生技术方案,本文的研究成果不仅可以为该实际工程的施工提供理论依据,为坝体内施工安全性作好预测,为施工技术方案可行性论证提供参考,也为解决其它的混凝土坝老化问题提供广阔的应用空间。更多还原

【Abstract】 With the time going on, the concrete dams grow and might be exceed their usage life-spans. The adverse conditions cause many problems such as movement, cracking, seeping, concrete deterioration and so on. So, how to rebuild, continue, enhance and rehabilitate the old dam has become an important problem for all hydraulic engineering researchers in the world. Among the puzzles about rebuilding, continuing and enhancing, how to deal with the joint surfaces between the old and new concrete and introducing effective methods to solve the problem of temperature control are two key points in construction. At present, a new technique, forming inner wall to prevent seeping by replacing dam concrete, is introduced to rehabilitate old dams, based on which this paper discuss the problems above.Taking a concrete gravity dam in northeast of china for example, this paper discusses and analyzes the systematic safety problem for dam rehabilitation. During the analysis, general software, ANSYS, which has its own program, APDL, is used to model the process of construction of representative portion. It is also used to perform the three-dimensional temperature field and thermal stresses during construction. When modeling the temperature field, the factors below should be considered: the parameters’ changes of concrete calorifics and mechanics with age of concrete, different materials of dam portions, different digging sequences, time of construction and the intervals, different digging and pouring sizes. The analysis results include the change rules of temperature field and thermal stresses with time, and the influence of some temperature controlling factors to them.Based on this rehabilitation technique of aging concrete dam, the results of this paper could be used as a theory not only to this engineering but also to other similar projects since it can predict the systematic safety of dam construction and provide effective reference for technique of construction.更多还原