小浪底排沙洞预应力混凝土衬砌结构应力状态分析

发布时间：2018-05-05 00:06

本文选题：衬砌结构 + 无粘结预应力　；参考：《天津大学》2014年硕士论文

【摘要】：环锚无粘结预应力衬砌结构在施工期和运行期受到自重、锚索预应力、洞室温度变化、内部高压水头等荷载的作用，在各种组合工况作用下其应力状态非常复杂，，如何采取有效手段对其应力状态进行分析和模拟是一个很棘手的问题。作为一种新型的结构形式，只有对其在各种工况下的应力状态进行全面、深入的分析，才能找出各种工况变化对其应力状态影响的规律，为今后的类似结构形式的应用提供有利的参考。在以往的研究中，对无粘结预应力衬砌施工张拉期的应力分析已经有了较多的研究结果，但对衬砌在温度变化和水头变化下的应力状态分析的研究结果还比较少。本文针对以上问题，基于小浪底历年实测资料，采用回归分析法对施工期温度变化对衬砌应力状态的影响进行了分析，采用单因子变量法对过水运行期水头变化对衬砌应力状态的影响进行了分析。同时，基于ANSYS有限元程序对施工期温度变化对衬砌应力状态的影响和过水运行期水头变化对衬砌应力状态的影响进行了深入的研究。结果表明，当衬砌内外温差为负值时，会使衬砌内侧混凝土的压应力减小，对衬砌内侧的应力状态会造成不利的影响；而内外温差为正值时，则对衬砌内侧应力状态有利。随着水位的增加，衬砌混凝土的环向压应力减小，即水头增大时会导致衬砌混凝土中由预应力锚索施加的环向压应力减小。但是无论是最大温差作用还是最大水头作用下，小浪底衬砌结构均处于安全运行的状态下。
[Abstract]:The ring anchor unbonded prestressed lining structure is subjected to deadweight during construction and operation, the anchor cable prestress, the temperature change of the cavern, the effect of high pressure water head load in the interior, and the stress state is very complex under various combined working conditions. How to use effective means to analyze and simulate the stress state is a very difficult problem. As a new type of structure, only through comprehensive and in-depth analysis of the stress state under various working conditions, can we find out the law of the influence of the variation of various working conditions on the stress state. It provides a favorable reference for the application of similar structural forms in the future. In the previous studies, there have been many results in stress analysis of unbonded prestressed lining construction during tensioning period, but the results of stress state analysis of lining under temperature and water head change are still few. In view of the above problems, based on the measured data of Xiaolangdi over the years, the effect of temperature change on the stress state of lining during construction period is analyzed by regression analysis method. The influence of water head change on lining stress state was analyzed by single factor variable method. At the same time, based on ANSYS finite element program, the influence of temperature change on lining stress state during construction period and the influence of water head change on lining stress state during overwater operation are deeply studied. The results show that when the inner and outer temperature difference of the lining is negative, the compressive stress of the inner lining concrete will be reduced, and the stress state of the lining inner side will be adversely affected, while the inner stress state of the lining will be favorable when the inner and outer temperature difference is positive. With the increase of water level, the circumferential compressive stress of lining concrete decreases, that is, when the water head increases, the circumferential compressive stress applied by prestressed Anchorage cable in lining concrete decreases. However, under the action of maximum temperature difference or maximum water head, the lining structure of Xiaolangdi is in safe operation.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV332

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