高混凝土拱坝的模型材料特性研究

发布时间：2018-05-19 15:12

本文选题：动态特性 + 配比　；参考：《大连理工大学》2014年硕士论文

【摘要】：我国是世界上水能资源最丰富的国家之一。大力发展水电逐步减少一次能源在能源结构中的比重,是进入21世纪我国能源发展的重要战略方针。我国80%以上的水能资源分布于西部,按照国家能源发展规划,预计在未来10年中要陆续建设超过百米甚至高达三百多米的世界级高坝；但西部又是我国主要的地震区,具有相当高的频度和烈度,因此对高坝的抗震技术研究不可避免且迫在眉睫。高坝的抗震安全评价目前主要依赖数值模拟进行研究,但是从试验角度来研究高坝地震反应问题,特别是坝体进入非线性阶段直到破坏的地震响应,仍是大坝抗震研究不可或缺的重要手段之一。本文以沙牌工程为研究背景,以混凝土仿真材料的动态特性为主要研究方向。目的是探索出一种合适配比的材料,为模型试验研究拱坝地震破坏形态和破坏机理做准备。论文的主要工作包括以下几个方面： 1、探索合适的配比,为模型试验做准备。通过调整配比,探索水灰比、粗细骨料配比、添加剂等对于模型材料抗压强度、劈裂强度、临界应变等性质的影响；并通过总结对比,选择出最优配比。试验结果表明重晶石、矿粉会提高材料的脆断性；重晶粉、砂子会降低材料的脆断性；随着龄期的增长,材料强度线性增长,脆断性明显提高； 2、探索加载速率对材料抗压强度、劈裂强度、临界应变等的影响；通过直拉试验,测量材料的抗拉强度。试验结果表明材料的抗压强度、劈裂强度、抗压吸能及抗压弹性模量都会随着加载速率的提高而提高； 3、通过不同尺寸试件的试验,探索试件形状对材料抗压特性的影响。试验结果表明单轴抗压强度会随着试件尺寸的变大而降低,且高宽比达到3：1时趋近于一定值；弹性模量和吸能会随着尺寸的增加而降低；尺寸会对试件的破坏形态产生影响。
[Abstract]:China is one of the countries with the most abundant water energy resources in the world. It is an important strategic policy for China to develop hydropower and gradually reduce the proportion of primary energy in the energy structure in the 21st century. More than 80% of the hydropower resources in China are distributed in the western part of the country. According to the national energy development plan, it is expected that more than 100 meters or even more than 300 meters of world-class dams will be built in the next 10 years, but the west is also the main earthquake area in our country. Because of its high frequency and intensity, it is inevitable and urgent to study the seismic technique of high dams. At present, seismic safety evaluation of high dams mainly depends on numerical simulation, but the seismic response of high dams is studied from the point of view of test, especially when the dam body enters the nonlinear stage until the seismic response of failure. It is still one of the most important methods in dam seismic research. This paper takes Shapai project as the research background and the dynamic characteristics of concrete simulation materials as the main research direction. The purpose of this paper is to explore a suitable material for model test to study the failure pattern and failure mechanism of arch dam. The main work of the thesis includes the following aspects: 1. To explore the appropriate ratio and prepare for the model test. The effects of water cement ratio, coarse aggregate ratio and additives on the compressive strength, splitting strength and critical strain of the model materials were explored by adjusting the ratio of water to cement, and the optimum ratio was selected by summing up and comparing. The experimental results show that barite and mineral powder can improve the brittle fracture of the material, the double crystal powder and sand will reduce the brittle fracture of the material, the strength of the material increases linearly with the increase of age, and the brittle fracture property increases obviously. (2) the influence of loading rate on the compressive strength, splitting strength and critical strain of the material is explored, and the tensile strength of the material is measured by Czochralski test. The results show that the compressive strength, splitting strength, compressive energy absorption and compressive elastic modulus of the material will increase with the increase of loading rate. 3. The influence of specimen shape on the compressive properties of the material was investigated through the experiments of different sizes. The experimental results show that the uniaxial compressive strength decreases with the size of the specimen and reaches a certain value when the aspect ratio reaches 3:1, the elastic modulus and energy absorption decrease with the increase of the size, and the size has an effect on the failure mode of the specimen.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV642.4;TV431

【参考文献】