深水桶式岸壁结构荷载传递特性与变形机理研究

Compared with the traditional marine structures, bucket structure has the advantages of economy, environmental protection, high efficiency and so on. It has a wide range of application prospects. Bucket structure has been used in breakwater engineering, but as a vertical quay structure, the safety and reliability of the structure has not yet been verified. Therefore, the study on load transfer character and deformation mode of deep-water bucket quay-wall structure can provide a theoretical basis for its application and the construction of wharf bulkhead, and greatly promote the development of marine infrastructure. The research topics are as follows: Through the centrifugal model test of bucket foundation structure with negative pressure sinking and backfill loading progress, it shows the bearing behavior and long term settlement mechanism of deep-water bucket quay-wall structure in different backfill form; Through the numerical simulation study on deep-water bucket quay-wall structure with different load forms, backfilling methods, structure forms, soil types, length-diameter ratios and other factors, it shows the main influencing factors of the deformation of deep-water bucket quay-wall structure, and the load transfer behavior of different backfill forms, Based on the theoretical analysis of the above test results, the coupling theory is established considering the effect between the lateral deformation and the vertical settlement. And a settlement calculation method of bucket quay-wall structure is established considering the interactions among backfill load, structure and soil. The research provides reference for the optimization design of deep-water bucket quay-wall structure.

相对于传统海工结构，桶式结构具有经济、环保和高效等优点，应用前景十分广阔。桶式结构在防波堤工程中已经得到了应用，但作为直立岸壁结构，其安全可靠性尚未得到验证。因此开展深水桶式岸壁结构荷载传递特性与变形机理研究，可为其应用于驳岸码头建设提供理论依据，大大推动海洋基础设施建设的发展。本课题拟开展负压下沉和回填加载下桶式结构的离心模型试验，揭示不同回填形式下深水桶式岸壁结构承载特性和长期沉降变形机理；通过桶式岸壁结构在不同荷载形式、回填方式、结构形式、土层类型和长径比等因素下的数值模拟研究，分析深水桶式岸壁结构变形的主要影响因素，验证不同回填形式下的荷载传递特性；基于上述试验结果进行理论分析，建立考虑侧向变形与竖向沉降的耦合制约理论，得到考虑回填荷载-结构-土相互作用的桶式岸壁结构工后沉降计算方法，为桶式岸壁结构的优化设计提供参考依据。

相对于传统海工结构，桶式结构具有经济、环保和高效等优点，应用前景十分广阔。桶式结构在防波堤工程中已经得到了应用，但作为直立岸壁结构，其安全可靠性尚未得到验证，因此开展了深水桶式岸壁结构荷载传递特性与变形机理研究。本课题利用申请人团队研制的大行程作动装置，开展了负压下沉和回填加载下桶式基础结构的离心模型试验，揭示了不同回填形式下深水桶式岸壁结构承载特性和长期沉降变形机理；通过桶式岸壁结构在不同荷载形式、回填方式、结构形式、土层类型和长径比等因素下的数值模拟研究，分析深水桶式岸壁结构变形的主要影响因素，验证不同回填形式下的荷载传递特性；基于上述试验结果进行理论分析，引入外荷载作用下地基土的变形系数，得到考虑各种外荷载-结构-土相互作用的桶式岸壁结构工后沉降计算方法。本项目发现桶式岸壁结构最大下沉总阻力在40000kN左右，桶体穿越上部淤泥土层时，桶壁及内隔板与土之间的摩擦系数约为0.125。当桶后吹填淤泥高度超过8m时，桶体结构发生了水平滑动失稳；当桶后回填袋装砂达到13.8m时，桶式岸壁结构仍是稳定的；桶式岸壁结构主要变形模式为向港侧倾斜和向海侧水平位移两种，破坏模式为滑动失稳。本项目的研究成果为桶式岸壁结构的优化设计提供参考依据，可为其应用与驳岸码头建设提供理论依据，对海洋基础设施建设的发展有一定推动作用。