刘桥泵站的渗流与结构稳定分析

发布时间：2018-04-01 22:02

本文选题：泵站　切入点：有限元　出处：《扬州大学》2015年硕士论文

【摘要】：刘桥泵站建于粉细砂地基上,而这类土壤颗粒之间无凝聚力或凝聚力很小,液化和管涌问题较为严重。在上下游水位差的作用下,泵站地基将会产生较大的渗透变形,严重时泵房将沉陷而遭到破坏。而由渗流产生的竖直向上的扬压力减小了泵房的有效重量,对泵房的抗滑不利。因此对刘桥泵站的渗流和结构稳定分析有着非常重要的意义。基于此,本文利用有限元软件ABAQUS对刘桥泵站的渗流场和应力场进行了模拟,主要研究内容有：对刘桥泵站粉细砂地基的渗流进行有限元分析,得出了其在上游不同作用水头下的位移、孔压、渗透水头和渗透坡降。结果表明,刘桥泵站砂土地基的渗透坡降都偏大,渗透稳定不满足要求,渗流问题是影响泵站安全运行的重大隐患,因此必须对其进行地基处理。为了保证刘桥泵站的正常运行,在泵室底部加设封闭的防渗墙,墙内用水泥土填充,对该经过地基处理后的泵站渗流进行有限元分析。结果表明,防渗墙大大改变了渗流场的分布,也大大降低了泵室底板下的渗透水头。水平段和出口段的渗透坡降远小于允许的渗流坡降临界值,刘桥泵站满足渗透稳定要求。对设有防渗墙的刘桥泵站整体进行有限元分析,得出泵站在各个工况下的应力分布规律。泵站最大主拉应力小于混凝土抗拉强度,最大主压应力小于混凝土抗压强度,泵站上部结构不会出现拉压应力破坏。泵房底板底部都处于受压状态,在泵室边墩底部和中墩底部,底板与防渗墙接触部位应力都很集中,泵室底板中间处的竖向应力分布比较均匀。泵室底板与地基接触的地方应力值都远远小于地基允许承载力,满足要求。三种工况下泵房的抗滑稳定系数都明显大于允许值,满足抗滑稳定要求。
[Abstract]:The Liuqiao pumping station is built on silty sand foundation, and there is no cohesion or little cohesion between these kinds of soil particles, so the problems of liquefaction and piping are serious. Under the action of the water level difference between upstream and downstream, the foundation of the pumping station will produce large seepage deformation. In severe cases, the pump room will sink and be destroyed. The vertical uplift pressure generated by the seepage reduces the effective weight of the pump room. Therefore, it is very important to analyze the seepage and structural stability of the Liuqiao pumping station. Based on this, the seepage field and stress field of the Liuqiao pumping station are simulated by the finite element software ABAQUS. The main research contents are as follows: the seepage of silty sand foundation in Liuqiao pump station is analyzed by finite element method, and the displacement, pore pressure, seepage head and seepage slope under different action head are obtained. The seepage slope of sand soil foundation of Liuqiao pump station is on the high side, and the seepage stability is not satisfied with the requirement. Seepage problem is a major hidden danger affecting the safe operation of the pump station, so it is necessary to treat the foundation. In order to ensure the normal operation of the Liuqiao pumping station, A closed cutoff wall was installed at the bottom of the pump chamber, and the soil was filled with water in the wall. The seepage of the pump station after the foundation treatment was analyzed by finite element method. The results show that the seepage field distribution has been changed greatly by the impervious wall. The seepage gradient of horizontal section and outlet section is far less than the allowable critical value of seepage gradient, and the Liuqiao pumping station satisfies the requirement of seepage stability. The finite element analysis of the whole Liuqiao pump station with impermeable wall is carried out. The maximum principal tensile stress of pumping station is smaller than the tensile strength of concrete, and the maximum principal compressive stress is less than the compressive strength of concrete. The bottom of the bottom plate of the pump room is in the state of compression, and the stress at the bottom of the side pier of the pump chamber and at the bottom of the middle pier, the contact part between the bottom plate and the impervious wall is very concentrated. The vertical stress distribution in the middle of the bottom plate of the pump chamber is relatively uniform. The local stress values of the bottom plate of the pump chamber and the foundation are far smaller than the allowable bearing capacity of the foundation, which satisfies the requirements. The coefficient of anti-slip stability of the pump room is obviously larger than the allowable value under the three working conditions. Meet the requirement of anti-slip stability.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV675;TV223.4

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