The various geotechnical issues that must be resolved in selecting a bridge pile foundation scheme are the focus of investigation and research. Based on the complex marine environment, the structural characteristics of the bridge (large span, high clearance, concentrated loads), and the distribution features of the rock and soil layers in the bridge area (deep bedrock, strong differential weathering), a comprehensive analysis indicates the following possible options for the bridge pile foundation scheme.

　　(1) Using the dense sand layer in the lower part of the Quaternary overburden as the pile tip bearing stratum, adopting the driven large-diameter steel pipe pile scheme with high geotechnical utilization efficiency. This scheme mainly has two major doubts. First, the pile driving depth will reach 70–80 m and must penetrate a considerable thickness of gravel-bearing dense sand layer; whether existing pile driving technology can handle this requires targeted practical verification. Second, even if a suitable pile diameter is used to drive the pile to the predetermined depth, whether the bearing capacity of a single pile can meet the design requirements also needs to be verified through tests.
　　(2) Using the fully and strongly weathered bedrock layer as the pile tip bearing stratum, either with driven steel pipe piles or bored piles. The driven steel pipe pile option faces the same doubts as scheme ①. The greater concern with this scheme is that the engineering properties of fully and strongly weathered rock vary significantly, and there are many uncertain factors in engineering application, so caution is advised.

　　(3) Using moderately weathered rock as the pile tip bearing stratum, adopting the bored rock-socketed pile scheme. This scheme is simple and feasible, with relatively few unknown risks. Of course, given the obvious differential weathering of bedrock in this area, reasonable quantitative research on rock strength is undoubtedly the top priority in investigation, analysis, and evaluation for the investigation and design of rock-socketed piles.