Under the soft soil geological condition,the problems of the settlement,destabilization,bottom pouring,super-settling and etc.

Considerations on crest settlement reservation in face slab dams design;

Early stage sedimentation of basin evolvement during Mesozoic went through an overlapping process from continental to marine facies, sedimentary overlap started from the alluvial/fluvial facies, along with intrusion, eruption and pyroclaistic sedimentation, reflecting a upward deepened transgression sequence, which indicates a rift basin.

Under complicated geological conditions,large slenderness ratio ultra-deep well sinks in the ultra-soft soil by prevented sinking method,sinks in hard soil by assisted sinking method,and in the process of sinking to take difficult technical measures of anti-tilt,correcting,and prevent sudden sinking to make large slenderness ratio ultra-deep wells vertically and evenly sink in the position.

Construction technology of super large sunk well in soft soil stratum