阜康抽蓄电站下库深厚覆盖层工程性质特征分析

Engineering characteristics analysis of deep overburden layer in Fukang pumping storage power station

阜康抽蓄电站下库覆盖层厚度达65 m左右,是以中、粗粒为主的漂石、砂卵砾石层,在平面和垂向上均无明显的分层特征,总体上整个深厚覆盖层可按同一土体进行评价。漂石、砂卵砾石层具有较高的承载和抗变形能力,深厚覆盖层的渗透系数为5.67×10^(-2) cm/s渗透能力较强。波速试验表明,漂石、砂卵砾石层的剪切波速自上而下逐渐递增,地层密实程度逐渐由松散到密实。研究区的主要工程地质问题为渗透变形和承载力问题,渗透变形破坏形式流土、管涌和过渡型均可存在,承载力问题则主要表现为地基不均匀沉降。

The overburden layer of Fukang pumping and storage power station is about 65 m thick,which is mainly composed of medium and coarse boulders,sand and gravel layers.There are no obvious stratification characteristics in plane and vertical direction,so it can be evaluated according to the whole deep overburden layer and the same soil.Boulders and gravel layers have higher bearing capacity and anti-deformation ability,and the permeability coefficient of deep overburden layer is 5.67×10^(-2) cm/s.The wave velocity test shows that the shear wave velocity of boulders and gravel layer increases gradually from top to bottom,and the stratum compactness gradually changes from loose to dense.The main engineering geological problems in the study area are seepage deformation and bearing capacity.The seepage deformation failure forms of flowing soil,pipe surge and transition can exist,while the bearing capacity problem is mainly manifested as uneven settlement of foundation.