覆盖层对面板堆石坝脱空的影响研究

Study on the Influence of Overburden on the Void of CFRD

面板作为修建在堆石坝上游的建筑物,其主要作用为挡水和防渗,由于堆石坝体和面板的材料属性差异较大,因此面板与坝体的变形相差较大,故而面板出现了脱空现象。本文结合具体的覆盖层上的某面板堆石坝工程,通过建立不同覆盖层厚度的面板堆石坝有限元计算模型,进行三维有限元计算分析,计算分析了大坝在竣工期的应力变形,在此基础上研究覆盖层对面板脱空的具体影响。结果表明,随着覆盖层厚度的增大,坝体的沉降、顺河向位移、横河向位移的最大值以及面板挠度和顺坡向应力的最大值均随之也在不断增大。覆盖层的存在一定程度上增大了面板脱空的极值,对大坝的安全运行产生了不利的影响,因此需提高覆盖层地基的承载力,减少大坝的不均匀沉降,可以有效地预防面板脱空现象的出现。

As a building built on the upstream of rockfill dam,the main function of panel is water retaining and seepage prevention.Because of the material properties of rockfill dam and panel are different,the deformation of the face pl|ate and dam body is different,so the face slab appears void phenomenon.In this paper,based on a concrete face rockfill dam project on the concrete cover,the face rockfill dam with different thickness of overburden is established The finite element model is used to calculate and analyze the stress and deformation of the dam during the completion period.On this basis,the concrete influence of the overburden on the slab void is studied.The results show that with the increase of overburden thickness,the maximum values of dam settlement,along river displacement,across river displacement,and the maximum values of slab deflection and along slope stress are increasing.The existence of overburden increases the extreme value of slab void to a certain extent,which has a negative impact on the safe operation of the dam.Therefore,it is necessary to improve the bearing capacity of overburden foundation and reduce the uneven settlement of the dam,which can effectively prevent the occurrence of slab void.