共查询到19条相似文献，搜索用时 250 毫秒
1.
研究目的:研究混凝土拱坝多尺度横缝单元和坝体损伤。创新要点:解决了拱坝坝段单元采用不同剖分形式(即多尺度剖分形式)时,在静动力荷载下,拱坝横缝开度和坝体损伤的计算。研究方法:首先建立大尺度交接面单元和小尺度单元坝段自由度耦合,然后建立大尺度交接面单元和大尺度单元坝段横缝单元模型,并对坝体损伤本构的计算进行研究。重要结论:通过对比计算发现,通过混凝土的损伤本构计算的应力峰值和实验结果相同,下降段的应力应变曲线基本吻合。提出的不同尺度横缝单元模型对坝体应力和横缝开度的计算误差在7%以内。 相似文献
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基于三维有限元计算软件ANSYS对某一高145 m的混凝土双曲拱坝进行开设大表孔与不开设表孔方案的计算对比分析,通过分析得出,高拱坝坝顶开设表孔对坝体应力的影响是局部的,主要集中在孔口周边,而对坝体下部几乎没有影响。最后,总结规律,希望为拱坝结构设计及体形优化提供参考。 相似文献
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华阳水库砌石拱坝裂缝和渗漏严重。为了了解大坝的结构工作性态,评价其安全性,根据大坝的实际情况,参照现行规范,采用拱冠梁法,对大坝的应力进行计算分析,复核其强度安全性。计算表明,在基本组合和特殊组合等4种工况下,坝体应力基本满足规范要求,该坝体结构的强度是安全的。 相似文献
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李怀斌 《贵阳学院学报(自然科学版)》2010,5(4)
马槽河水电站拦河大坝是一座外掺MgO不分横缝的拱坝,在施工图阶段通过对坝址地质条件深入细致的研究,将初步设计阶段的抛物线拱圈优化为统一二次曲线形拱圈的双曲拱坝,在使坝体应力水平及坝肩抗滑稳定满足要求的前提下,节省了坝基开挖及坝体混凝土工程量;同时采用MgO筑坝技术,降低了施工难度,使得电站提前发电.获得了良好的经济效益及社会效益. 相似文献
5.
简要介绍了某水电站混凝土面板堆石坝工程概况和流变计算模型。采用三维有限单元法对该混凝土面板坝筑坝及蓄水过程进行模拟计算,对比考虑堆石料流变和不考虑流变的两种计算结果,分析说明筑坝材料的流变特性对面板坝坝体以及混凝土面板变形应力的影响。 相似文献
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沥青心墙坝堆石坝应用广泛,筑坝材料主要有沥青心墙、堆石、砂砾石等,材料的应力-应变关系为非线性关系。建立坝体的三维模型,采用分级加载方式模拟坝体填筑过程,使模型单元和材料性质随时间改变,较好地计算了坝体的应力和应变。 相似文献
7.
杨文华 《Journal of Zhangzhou Technical Institute》2004,6(1):74-76
抛物线双曲拱坝的坝面几何形状复杂,在施工放样中其坐标的计算工作量很大.应用 Excel 2000计算放样数据,简单易学,操作方便,可以提高放样数据的处理效率.介绍了利用 Excel2000 来计算拱坝放样数据的方法和过程. 相似文献
8.
杨文华 《漳州职业大学学报》2004,6(1):74-76
抛物线双曲拱坝的坝面几何形状复杂，在施工放样中其坐标的计算工作量很大。应用Excel2000计算放样数据，简单易学，操作方便，可以提高放样数据的处理效率。介绍了利用Excel2000来计算拱坝放样数据的方法和过程。 相似文献
9.
林承岸 《长江工程职业技术学院学报》2011,(4):6-9
通过对小型水库大坝的渗流和稳定进行计算,得出坝体存在渗透破坏和下游坝坡不稳定隐患,需进行加固处理。根据大坝基础地质、坝体填筑材料以及施工质量等条件,选择3种大坝防渗加固方案并进行优选,同时对大坝坝体进行综合整治;经对加固后的坝体稳定进行校核,结果表明大坝除险加固后安全可靠。 相似文献
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11.
《天津大学学报(英文版)》2017,(5)
The construction of arch dams exhibits high uncertainty. Sensitivity analysis of construction parameters is important for the design and optimization of dam construction duration. However, current research cannot fully consider the combined influences of multiple parameters on the total construction. To effectively analyze the duration of arch dam construction, this study proposes a global comprehensive sensitivity analysis method in view of the whole process of arch dam construction based on an orthogonal experiment. This method could comprehensively consider the influence of the construction parameters that may lead to the uncertainty of construction duration. In addition, this method is able to identify the key parameters that may have a significant effect on duration uncertainty and sums up the general rules of combined parameters' interaction effect, which provides a scientific basis for reasonable optimization of the duration of dam construction. 相似文献
12.
Sequence placement logic plays a significant role in construction simulation of high arch dams and directly affects the simulation process and results. To establish a sequence logic for dam block placement, the construction scheme, real-time construction process, and random factors of the site all need to be considered in detail. There are few studies available currently that take all these factors into consideration. To address this problem, a real-time update of sequence placement logic for high arch dams based on evidence weight discount is proposed in this study. First, the subjective weight of the dam block sequence priority criteria is built using a consistent matrix method based on the construction scheme. Second, using evidence theory, dynamic objective weight of the priority criteria and basic probability assignment is built. Finally, using a weight self-adaptive adjustment method and comprehensive evidence discounting, the placing probabilities of different dam blocks are obtained. A case study indicates that this method can realize real-time update of sequence placement logic. 相似文献
13.
A new contraction joint element model for the interface in different meshes between the arch dam sections is con- structed. The study on the elastic-plastic damage constitutive model for concrete, which is applied to multi-axial stresses, is also taken. The models of the dam-foundation-reservoir system for Xingbiling and Jinping concrete arch dams, China are calculated using the proposed contraction joint elements and the elastic-plastic damage constitutive model to verify the proposed models. Results showed that the proposed contraction joint element model has a high precision in simulating the behavior of contraction joints and the elastic-plastic damage constitutive model has a high precision in simulating the behavior of the damage to the concrete. 相似文献
14.
An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method. 相似文献
15.
Calculation Model of Equivalent Strength for Induced Crack Based on Double-K Fracture Theory and Its Optimizing Setting in RCC Arch Dam 总被引：2，自引：0，他引：2
By means of fracture testing on roller-compacted concrete (RCC) three-point bending beams with two different specimen sizes, the P-CMOD complete curve for RCC was gained. Furthermore, by applying double-K fracture theory, KIC^ini,KIC^un, as well as the critical effective crack length and the critical crack tip opening displacement, were evaluated. Based on the double-K fracture parameters above, the calculation model of equivalent strength for induced crack was established, thus the calculation method on its initiation, stable propagation and unstable fracture was ascertained. Moreover, the finite element simulation analysis of stress field in ShaPai arch dam and the on-site observational splaying points of induced crack at different altitudes validated the reliability of the model. Finally, crack inducer‘s optimal setting in RCC arch dam was studied. It improves the design level of induced crack in RCC arch dam and satisfies the necessity of engineering practice. 相似文献
16.
随着施工技术的飞速发展,混凝土面板堆石坝已经成为现代水利枢纽工程的主要坝型之一。渭南市涧峪水库在堆石面板坝的施工中,采用了先进的挤压式混凝土边墙施工技术,提高了施工质量,为同类工程施工积累了宝贵的经验。 相似文献
17.
土石坝的除险加固方案中常采用冲抓套井回填夯实粘土作为防渗体,即粘土心墙防渗体,该方法已在许多水库和相当长度的堤防工程建设中得到广泛的应用;然而其渗透稳定一直是工程设计和施工中的关键问题之一.本文结合某水库土石坝除险加固工程坝体渗透稳定问题,开展了坝体心墙粘土的物理特性、渗透特性、临界坡降的研究,为工程设计和施工提供了必要的分析成果和参考依据. 相似文献
18.
广大小型水库及山塘土坝的除险加固问题是陕西省彻底消除病险水库安全隐患的重要途径。本文针对黄土地区小型土坝常见的渗漏及结构安全等病害问题,分析导致病险的原因及关键技术问题,特别指出抗震性能与坝顶交通是当前陕西省小型土坝安全评价的新问题。结合大中型土坝病险加固的经验与教训,提出黄土区小型土坝除险加固关键技术问题的对策及措施。 相似文献
19.
In this paper, the characteristics of two-dimensional viscous flow over two dams were numerically investigated. The results show that the behavior of the vortices is closely related to the space between two dams, water depth, Fr number and Reynolds number. In addition, the flow properties behind each dam are different, and the changes over two dams are more complex than over one dam. Finally, the relevant turbulent characteristics were analyzed. 相似文献