拱坝坝肩、坝底局部加厚对坝体应力影响分析

发布时间：2019-03-14 18:39

【摘要】：拱坝结构应力分析是拱坝设计的重要组成部分，，尤其是对规模庞大和技术难度高且超出已有设计规范的高拱坝。大量的工程经验表明,拱坝最大主应力常出现在坝肩和坝底处,特别是拉应力过大会导致坝肩失稳甚至溃坝等措施对坝体应力的影响,给出了满足拱坝规范设计要求的综合加厚方案。本文介绍了国内拱坝发展现状提出了论文技术路线,首先利用ANSYS建立拱坝三维在限元计算模型，总结了拱坝有限元等效应力法的计算和实现过程。介绍了静水压力、泥沙压力、扬压力、重力、弧门推力等荷载施加方法,研究了已有高拱坝工程中拱坝坝体结构设计中的加切角问题:分析了加切角对拱坝结构应力的影响,在2种工况下与不加切角方案作了应力分析,结果表明:拱坝坝肩加切角措施能有效减小坝肩应力。其次对拱坝坝底的3种不同加厚位置进行研究，在不同工况下对比分析了坝底上游加厚、坝底下游加厚和坝底上、下游均加厚方案的应力状况,得出坝底下游加厚方案能有效减小坝底应力;并对坝底下游加厚方案的加厚尺寸初步优化,即分别对坝底下游加厚3m,6m、9m进行应力分析,计算结果表明:拱坝坝底向下游加厚6m,坝底处应力值可满足规范设计要求。最终提出了对坝肩、坝底均加厚的综合方案,即:坝肩上游切角厚2m,坝肩下游切角厚2.8m,坝体501至510m高程向下游加厚6m。并计算了综合方案下5种工况的拱坝坝体应力,计算结果表明:采取综合加厚方案,拱坝应力标准可满足拱坝规范设计要求。
[Abstract]:Stress analysis of arch dam structure is an important part of arch dam design, especially for high arch dam with large scale and high technical difficulty. A large number of engineering experiences have shown that the maximum principal stress of arch dam often occurs at the abutment and bottom of the dam, especially the influence of the measures such as instability of abutment and even dam break caused by excessive tensile stress on the stress of dam body. A comprehensive thickening scheme to meet the design requirements of arch dam code is presented. In this paper, the present situation of arch dam development in China is introduced and the technical route is put forward. Firstly, the 3D in-situ finite element calculation model of arch dam is established by using ANSYS, and the calculation and realization process of finite element equivalent force method for arch dam are summarized. This paper introduces the loading methods of hydrostatic pressure, sediment pressure, lifting pressure, gravity, arc gate thrust, etc., and studies the problem of adding shear angle in the structure design of arch dam in the existing high arch dam engineering. The influence of the shear angle on the structural stress of arch dam is analyzed, and the influence of shear angle on the stress of arch dam structure is analyzed. The stress analysis of the arch dam abutment and the non-cutting angle scheme is made under two conditions. The results show that the stress of the abutment of arch dam can be effectively reduced by adding the angle of the arch dam abutment. Secondly, three different thickening positions of arch dam bottom are studied, and the stress status of upstream thickening, downstream thickening of dam bottom and average thickening scheme of upper and lower reaches of dam bottom are compared and analyzed under different working conditions. It is concluded that the dam bottom stress can be effectively reduced by the thickening scheme at the downstream of the dam bottom. At the same time, the initial optimization of the thickening scheme of the downstream dam bottom is made, that is to say, the thickness of the downstream dam bottom is increased by 3m, 6m and 9m respectively. The calculated results show that the stress value at the bottom of the arch dam can meet the design requirements of the code when the bottom of the arch dam is thickened downstream by 6m. Finally, a comprehensive scheme is put forward to thicken the abutment and the bottom of the dam, that is, the thickness of the upstream cut angle of the dam abutment is 2m, the thickness of the downstream cut angle of the abutment is 2.8m, and the height of the dam body from 501 to 510m is thickened to the downstream of the dam body by 6 m. The stress of arch dam under five conditions under the comprehensive scheme is calculated. The results show that the stress standard of arch dam can meet the design requirements of arch dam code by adopting the scheme of comprehensive thickening.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV642.4

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