The surroundings and geological conditions of waterfront excavation enclosure in deep riprap foundation are very complex,which are quite different from those of conventional foundation excavation enclosure.The traditional enclosure structures cannot be fully applied in the complex conditions.In this paper,the design of waterfront excavation in deep riprap foundation behind a cruise terminal is referred to solve the difficult problems of complex geological conditions,high environmental protection requirements,difficulty in waterproof technology and so on.Firstly,two excavation enclosure schemes are proposed to comparatively analyze through calculation.Secondly,based on pumping test of enclosed well,the water sealing effects of two different enclosure schemes,concluding piercing occlusion pile and piercing grouting pile together with high pressure jet grouting pile,are compared.The test results show that the piercing occlusion pile has the dual functions of supporting and water-proof curtain,and can be implemented well in waterfront excavation in riprap foundation.Then the piercing occlusion pile is determined to be excavation enclosure scheme.Finally,a model is established by the software Plaxis 2D to analyze the deformation of recommendation excavation enclosure scheme on the adjacent wharf.The design scheme of piercing occlusion pile adopted in the deep riprap layer near the sea has the characteristics of structural safety,reliability and good sealing effect.It successfully works out the difficult technical problems of construction and water sealing under the complex environment.And it can provide reference for similar excavation projects.