Abstract: The wave-induced seabed liquefaction is the main cause of gedegical disasters at the Chengdao Sea of the Yellow River Estuary, an oil production area. In this paper, a theoretical calculation model was established for assessing the seabed liquefaction, and calculating the liquefaction depth at different drills at the Chengdao Sea; further more, the direction of flow-slide was gotten. Through study some conclusions were gotten. (1) Under extreme sea conditions, the region with larger liquefaction depth lies at the central and southeastern of the Chengdao Sea, the weak soil layer up to 10 m can liquefy. The liquefaction depth can reach 4~8 m at the north, and liquefaction depth at the southwest is relatively little, 〖JP2〗within 3 m. (2) The flow-slide directions of the seabed after liquefaction are as follows, soil at north slide to north, soil at middle firstly slides to east and then to northeast, soil at the southeast may slide to southeast or be residual. The liquefaction depth and slide direction can be used for petroleum engineering design and construction reference.

Key words: the Yellow River Estuary, the Chengdao Sea, wave, liquefaction