重力坝运行期温度场及温度应力分析

发布时间：2018-02-12 03:33

本文关键词： 重力坝运行期温度场温度应力　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：混凝土重力坝作为一种重要的坝型，，由于其具有设计方法简单，运行安全可靠，对地形、地址条件适应性强等特点，被广泛运用，混凝土重力坝温度应力是影响坝体安全的主要因素，所以开展该方面的研究具有重要应用价值。本文以刘家峡水电站主坝Ⅸ非溢流坝段作为工程实例，采用ANSYS软件计算其1月和7月的准稳定温度场和温度应力，以及在1月准稳定温度场基础上计算寒潮对大坝温度场和温度应力的影响，和在7月准稳定温度场基础上计算气温日变化对大坝温度场和温度应力的影响，主要研究成果如下：（1）对刘家峡水电站Ⅸ非溢流坝段的温度场进行仿真分析。先计算模型的边界条件，再用ANSYS进行模拟分析，计算出1月和7月的准稳定温度场，1月寒潮期间的瞬态温度场和7月气温日变化的瞬态温度场。（2）计算出刘家峡Ⅸ非溢流坝段的位移，高温和低温季节引起坝体位移随着季节变化呈现周期性变化，高温时，坝体向上游倾斜；低温时，向下游倾斜，7月位移分量达到最大，1月时位移分量达到最小。（3）对刘家峡水电站Ⅸ非溢流坝段的应力场进行仿真分析。计算出1月和7月的稳定温度应力，1月寒潮期间非稳定温度应力及7月气温日变化非稳定温度应力。在1月低温时期，冬季温度引起的拉应力是相当大的，接近坝段混凝土的抗拉强度，如果在这个基础上加上寒潮，就有可能产生裂缝，7月高温时期，温度荷载引起的应力主要是压应力，坝区昼夜温差大，混凝土表面温度和内部温度存在较大的温度差，将引起相当大的应力，对坝体表面不利。气温骤降和气温日变化对坝段的影响在表层0.5～1m的范围内，对其内部的温度影响不大，所以在坝面附近出现应力。本文的研究结果为刘家峡水电站运行期的维护和补强提供一定的技术依据。
[Abstract]:As an important dam type, concrete gravity dam is widely used because of its simple design method, safe operation, strong adaptability to terrain and address conditions, etc. The thermal stress of concrete gravity dam is the main factor that affects the safety of dam body, so it has important application value to carry out the research in this field. Taking the non-spillway section of the main dam of Liujiaxia Hydropower Station as an engineering example, the quasi-stable temperature field and temperature stress in January and July are calculated by ANSYS software. The influence of cold wave on dam temperature field and temperature stress is calculated on the basis of January quasi-stable temperature field, and the influence of diurnal variation of temperature on dam temperature field and temperature stress is calculated based on July quasi-stable temperature field. The main research results are as follows:. 1) the temperature field in the non-spillway section of Liujiaxia Hydropower Station is simulated and analyzed. The boundary conditions of the model are calculated first, and then the ANSYS is used to simulate and analyze the temperature field. The quasi-stable temperature field on January and July, the transient temperature field during the cold wave of January and the diurnal variation of temperature in January are calculated. (2) the displacement of the non-spillway dam section of Liujiaxia IX is calculated. The displacement of the dam body changes periodically with the seasonal variation of high temperature and low temperature. At high temperature, the dam tilts upstream, and at low temperature, The displacement component reaches the maximum in July and the smallest in January. The stress field of the non-spillway dam of Liujiaxia Hydropower Station has been simulated and analyzed. The steady temperature stress of January and July, the unsteady temperature stress during January cold wave and the diurnal variation of temperature in January have been calculated. The tensile stress caused by winter temperature is quite large, which is close to the tensile strength of concrete in dam block. If the cold wave is added on this basis, cracks may occur. During the high temperature period in July, the stress caused by temperature load is mainly compressive stress. The temperature difference between day and night in the dam area is large, and the temperature difference between the concrete surface temperature and the inner temperature will cause considerable stress, which will be unfavorable to the dam body surface. The sudden drop of temperature and the diurnal variation of temperature will affect the dam section in the range of 0.5m in the surface layer. It has little effect on the internal temperature, so the stress appears near the dam surface. The results of this paper provide some technical basis for the maintenance and reinforcement of Liujiaxia Hydropower Station.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV642.3;TV315

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