前言葛洲坝工程地基岩体为下白垩系河流相红色碎屑岩。复杂多变的河流沉积条件,沉积了一整套粘土矿物含量较高的泥质软岩为主的地层。在整个地层中,夹有数量巨多、形态多变的各种类型粘土岩夹层。在地质构造作用下,粘土岩夹层受到剪切错动破坏,形成不同程度的泥化夹层。泥质软岩成岩作用较差,岩性软弱,抗压强度低,变形模量小,风化速度快,基坑开挖后产生卸荷回弹 Foreword The foundation rock mass of the Gezhouba Project is the lower Cretaceous fluvial red clastic rock. Complex and fluctuating river sedimentary conditions have deposited a whole set of layers dominated by argillaceous soft rock with high clay mineral content. In the entire formation, there are a large number of various types of clay rock sandwiches. Under the action of geological structure, the clay rock interlayer is damaged by shearing, forming different layers of clay interlayer. Silt soft rock has poor diagenesis, weak lithology, low compressive strength, small deformation modulus, rapid weathering, and unloading rebound after excavation