硬质岩基条件下沉箱码头的抛石棱体优化设计

对于硬质基岩条件下的重力式沉箱码头，通常在沉箱后方设置抛石棱体，用以减小沉箱宽度，从而缩减基槽开挖范围内的炸礁量。依托某海外工程，对棱体高度和工程造价的关系进行分析，探究抛石棱体的优化设计规律。结果表明，当抛石棱体高度约为沉箱高度的60%~80%时，工程造价最低；在硬质岩面低于沉箱高度的1/2时，抛石棱体的最优高度为沉箱高度的60%左右；在硬质岩面高出沉箱高度的1/2时，抛石棱体的最优高度为沉箱高度的80%左右。揭示的规律可供类似项目参考，实际工程中应综合考虑工程地质条件、地材价格、施工能力等多方面因素，分析确定经济合理的棱体高度。

Optimization design of riprap prism for caisson wharf under hard rock foundation conditions

For gravity caisson quay under hard bedrock conditions，riprap prisms are usually installed behind the caissons to reduce the width of the caissons，and reduce the amount of reef blasting within the excavation range of the foundation trench.This article relies on an overseas project to analyze and study the relationship between the height of the prism and the engineering cost，so as to explore the optimal design rules of the riprap prism.The results show that the engineering cost is the lowest when the height of the riprap prism is about 60%~80% of the height of the caisson.When the hard rock surface is lower than 1/2 of the height of the caisson，the optimal height of the riprap prism is about 60% of the height of the caisson.When the hard rock surface is 1/2 higher than the height of the caisson，the optimal height of the riprap prism is about 80% of the height of the caisson.The laws revealed in this article can be used as a reference for similar projects.In practical projects，multiple factors such as engineering geological conditions，ground material prices，and construction capacity should be comprehensively considered to analyze and determine an economically reasonable prism height.