有限元法在泥石流重力式拦砂坝受力分析中的应用研究
文献类型：学位论文
| 作者 | 卢铖昀 |
| 学位类别 | 硕士 |
| 答辩日期 | 2008 |
| 授予单位 | 中国科学院水利部成都山地灾害与环境研究所 |
| 授予地点 | 成都 |
| 导师 | 王士革 |
| 关键词 | 泥石流 重力式拦砂坝 有限元法 稳定分析 |
| 学位专业 | 岩土工程 |
| 中文摘要 | 重力式拦砂坝是泥石流防治中经常采用的一种工程措施，是修建在泥石流沟谷内靠其自身重量以及同地基间的摩擦力来维持稳定的实体混凝土坝或圬工坝。拦砂坝的稳定是泥石流拦砂坝设计的关键，拦砂坝的稳定分析，主要包括抗滑移稳定计算、抗倾覆稳定计算和地基承载力计算，目前多以传统的材料力学法进行计算。有限元法是一种数值计算方法，即将实际的结构划分为一系列的离散单元（这些单元通过公共节点连接在一起），然后对这些单元的组合进行受力分析。该方法在工程结构计算中应用广泛，但在泥石流拦砂坝受力分析中的应用研究较少。本论文探索有限元法应用于拦砂坝稳定分析方面的可行性，为今后的泥石流重力式拦砂坝设计提供一些参考。 本文在归纳重力式拦砂坝的特点、荷载组合，以及与水工重力坝区别的基础上，以四川省宁南县石洛沟后山电站拦砂坝为原型，采用ANSYS有限元软件，针对不同的库容下的荷载组合，对泥石流重力式拦砂坝进行二维数值模拟，计算其稳定性，并与传统的材料力学法进行对比分析，可以得到以下结论：（1）有限元法进行拦砂坝稳定计算的二维模型尺寸为：坝下深度取1倍坝高，坝前长度取1倍坝高，坝后长度取2倍坝高。（2）有限元法进行拦砂坝稳定计算的位移边界条件为：坝基底部X方向和Y方向固定约束。（3）根据材料力学法和有限元法的计算结果，对比分析抗滑系数可知拦砂坝最不利荷载组合为：空库下、稀性泥石流过流时的荷载组合。（4）有限元法在拦砂坝抗滑稳定系数计算中的应用前景良好，所得结果比材料力学法计算结果更准确。对于石洛沟后山电站拦砂坝而言，有限元法所得抗滑系数是材料力学法所得抗滑系数的2倍左右，但该结论是否对于所有泥石流拦砂坝都满足，有待进一步研究。（5）应用有限元法对拦砂坝抗倾稳定进行计算，结果表明抗倾覆系数对荷载变化敏感，且计算量大，需要进一步改进计算方法。（6）根据有限元法计算所得应力应变图，得出拦砂坝的薄弱区为拦砂坝背水面坝脚处和坝体溢流口处。 |
| 英文摘要 | Gravity silt-trap dam is a kind of engineering measure to control the debris flow.It is a masonry dam or entities concrete dam which is constructed on a debris flow valley and maintain its stability by own weight and friction with the foundation to maintain stable. The safety and stability of Silt-trap dam is the key of debris flow silt-trap dam design. The stability analysis of silt-trap dam, including anti-slip stability, anti-overturning stability and foundation bearing capacity calculation, now is often calculated by the traditional material mechanical method. The finite element method is a numerical method, which divided into a series of discrete units (these units connected by public nodes), then analyse the combination of these elements .This is popular in the existing engineering structure computing application, but the analysis in the debris flow silt-trap dam is less. The objective of this paper is to explore the application of finite element method in silt-trap dam stability analysis, so as to provide some reference for the future gravity silt-trap dam design. This paper is based on the summary of the gravity silt-trap dam’s characteristics, load combinations and the difference with the hydraulic gravity dam, using ANSYS finite element software, the author simulated two-dimensional numerical calculation at the debris flow gravity silt-trap dam for the load combination under the different storage ,taking Ning-nan shiluo gully Hou-Shan power-station dam of Ning-nan county in Sichuan province as an example. Comparing the traditional material mechanical method, we can reach some conclusions as follows:(1) Using finite element method to calculate the stability coefficient of silt-trap dam, the general two-dimensional model size: dam depth downstream is one times of the dam height, dam length downstream is 1 times of the dam height, the dam length upstream is 2 times of the dam height.(2) Using finite element method to calculate the stability of silt-trap dam, the boundary condition is the basis of a fixed dam downstream constraints.(3) According to the results calculated by the mechanical method and the finite element method, we can reach a conclusion that the most disadvantaged load combination is under space storage of a non-viscous debris flow .(4)The application of the finite Element Method in silt-trap dams stability analysis has a good prospect, and the results are more accurate than the results calculated by the mechanical method. Generally speaking, the anti-sliding coefficient calculated by the finite element is 2 times of the results calculated by the mechanical method.(5)Using finite element method to calculate the anti-dumping coefficient of silt-trap dams, the results show that the anti-overturning coefficient is sensitive to load. In addition the method have a large computation amount and needs to be further improved . (6) Using the finite element method to calculate stress and strain, we know that the weak areas of the silt-trap dam is dam feet on the dorsal surface. |
| 学科主题 | 岩土力学 |
| 语种 | 中文 |
| 公开日期 | 2010-10-14 |
| 分类号 | O31;P64 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2190]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） |
| 推荐引用方式 GB/T 7714 | 卢铖昀. 有限元法在泥石流重力式拦砂坝受力分析中的应用研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2008. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。