深卸荷裂隙带混凝土面板堆石坝趾板基础处理研究
发布时间：2018-07-16 20:49
【摘要】：梨子坪混凝土面板堆石坝坝高77.5m，属于中等高度坝。该坝坝基岩体倾角平缓，卸荷裂隙发育。坝基开挖和防渗处理是混凝土面板堆石坝设计的重要环节，对坝体的稳定、沉降、变形、防渗乃至大坝的安全运行均有较大影响。趾板不仅是面板和地基的连接结构，，同时也是防渗帷幕的连接体，起到承上启下的特殊作用，所以对于面板堆石坝的趾板这一关键部位进行研究很有必要。 本文在系统总结了工程区及趾板区地质特性基础之上，根据地质勘测及试验资料，建立了面板坝地质模型对趾板建基面应力、应变、变形位移范围等进行研究并根据结果选择建基面高程。 鉴于梨子坪面板坝所处地质环境以及建坝稳定安全性考虑，研究梨子坪面板坝的基础处理措施显得非常必要。与此同时，对趾板基础岩体进行固结灌浆后的效果分析以及对于灌浆处理后趾板建基岩体质量的改善程度同样也是值得研究和分析的。 本文的主要结论如下： ①根据地质岩石（体）特性，对建基岩体进行了分类：直接利用岩体、开挖利用岩体和开挖清除岩体。根据混凝土面板堆石坝模型分析和从自身抗冲蚀能力出发，趾板基础开挖深度应至弱卸荷岩体（声波测速值不小于3000m/s）。如果受到工程条件的局限，部分基础无法挖到弱卸荷下部岩体时，建议采取固结灌浆布设锚杆等结构措施进行处理，以提高趾板建基岩体质量，达到工程设计要求。 ②根据地质勘察资料建立大坝及趾板的有限元模型，在不同工况下对其进行应力、变形、位移分析，得到其塑性变形范围、应力分布情况、各方向最大位移，分析结果有助于大坝趾板建基面的选择。 ③本文研究采用了“均匀固结+帷幕”的布孔型式以应对梨子坪大坝趾板基础岩体倾角平缓、地质缺陷类型多样、后期处理难的特点，能够满足大坝安全运行的要求。 4研究认为固结灌浆不仅提高了建基岩体的整体性和均一性、减小了渗水力比降、增强了趾板基础浅部防渗帷幕体的厚度及其致密性。 同时，本文系统详尽地说明了梨子坪混凝土面板堆石坝址区域环境、工程岩体特点、工程地质条件等，论文所涉内容资料翔实、符合实际情况，所积累的处理问题的方法和工程经验，可以作为其它类似工程的参考。
[Abstract]:The dam height of Liziping concrete face rockfill dam is 77.5 m, which belongs to medium height dam. The dipping angle of the dam foundation rock mass is gentle and the unloading fissure is developed. The excavation and seepage prevention of dam foundation is an important link in the design of concrete face rockfill dam, which has great influence on the stability, settlement, deformation, seepage prevention and even the safe operation of the dam. Toe slab is not only the connection structure of face slab and foundation, but also the connection body of impervious curtain, so it is necessary to study the toe slab of face rockfill dam. On the basis of systematically summarizing the geological characteristics of the engineering area and the toe slab area, according to the geological survey and test data, the stress and strain of the foundation plane of the face slab are established by the geological model of the face slab dam. The range of deformation and displacement is studied and the height of foundation surface is selected according to the result. In view of the geological environment of Liziping concrete slab dam and the safety of dam construction, it is necessary to study the foundation treatment measures of Liziping face slab dam. At the same time, it is also worth studying and analyzing the effect analysis after consolidation grouting and the improvement of the quality of toe slab foundation rock mass after grouting treatment. The main conclusions of this paper are as follows: 1 according to the characteristics of geological rocks (bodies), the author classifies the base rock mass: directly using rock mass, excavating using rock mass and excavating removing rock mass. Based on the model analysis of concrete face rockfill dam and its erosion resistance, the excavation depth of toe slab foundation should be up to weak unloading rock mass (the sonic velocimetry value is not less than 3000m/s). If some foundation can not be excavated to weak unloading rock mass due to the limitation of engineering conditions, it is suggested to take structural measures such as consolidation grouting and anchoring to improve the quality of the toe slab foundation rock mass. According to the data of geological survey, the finite element model of dam and toe slab is established, and the stress, deformation and displacement are analyzed under different working conditions, and the range of plastic deformation and the distribution of stress are obtained. The maximum displacement in each direction is helpful to the selection of the foundation surface of the dam toe plate. 3 the "uniform consolidation curtain" is adopted in this paper to deal with the slope of the toe plate foundation rock mass of the Liziping dam. The characteristics of various types of geological defects and difficult post-treatment can meet the requirements of safe operation of dams. 4 it is considered that consolidation grouting not only improves the integrity and uniformity of foundation rock mass, but also reduces the water permeability ratio. The thickness and compactness of the shallow impervious curtain body of toe plate foundation are enhanced. At the same time, the regional environment, characteristics of engineering rock mass and engineering geological conditions of the site of Liziping concrete face rockfill dam are described in detail in this paper. The contents of the paper are full and solid, which are in line with the actual situation. The accumulated methods and engineering experience can be used as reference for other similar projects.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV223
本文编号：2127632
[Abstract]:The dam height of Liziping concrete face rockfill dam is 77.5 m, which belongs to medium height dam. The dipping angle of the dam foundation rock mass is gentle and the unloading fissure is developed. The excavation and seepage prevention of dam foundation is an important link in the design of concrete face rockfill dam, which has great influence on the stability, settlement, deformation, seepage prevention and even the safe operation of the dam. Toe slab is not only the connection structure of face slab and foundation, but also the connection body of impervious curtain, so it is necessary to study the toe slab of face rockfill dam. On the basis of systematically summarizing the geological characteristics of the engineering area and the toe slab area, according to the geological survey and test data, the stress and strain of the foundation plane of the face slab are established by the geological model of the face slab dam. The range of deformation and displacement is studied and the height of foundation surface is selected according to the result. In view of the geological environment of Liziping concrete slab dam and the safety of dam construction, it is necessary to study the foundation treatment measures of Liziping face slab dam. At the same time, it is also worth studying and analyzing the effect analysis after consolidation grouting and the improvement of the quality of toe slab foundation rock mass after grouting treatment. The main conclusions of this paper are as follows: 1 according to the characteristics of geological rocks (bodies), the author classifies the base rock mass: directly using rock mass, excavating using rock mass and excavating removing rock mass. Based on the model analysis of concrete face rockfill dam and its erosion resistance, the excavation depth of toe slab foundation should be up to weak unloading rock mass (the sonic velocimetry value is not less than 3000m/s). If some foundation can not be excavated to weak unloading rock mass due to the limitation of engineering conditions, it is suggested to take structural measures such as consolidation grouting and anchoring to improve the quality of the toe slab foundation rock mass. According to the data of geological survey, the finite element model of dam and toe slab is established, and the stress, deformation and displacement are analyzed under different working conditions, and the range of plastic deformation and the distribution of stress are obtained. The maximum displacement in each direction is helpful to the selection of the foundation surface of the dam toe plate. 3 the "uniform consolidation curtain" is adopted in this paper to deal with the slope of the toe plate foundation rock mass of the Liziping dam. The characteristics of various types of geological defects and difficult post-treatment can meet the requirements of safe operation of dams. 4 it is considered that consolidation grouting not only improves the integrity and uniformity of foundation rock mass, but also reduces the water permeability ratio. The thickness and compactness of the shallow impervious curtain body of toe plate foundation are enhanced. At the same time, the regional environment, characteristics of engineering rock mass and engineering geological conditions of the site of Liziping concrete face rockfill dam are described in detail in this paper. The contents of the paper are full and solid, which are in line with the actual situation. The accumulated methods and engineering experience can be used as reference for other similar projects.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV223
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本文编号：2127632
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