前墙-土体-遮帘桩共同作用下遮帘式板桩码头承载机理及计算理论研究

With the development of wharf construction into large size and application in the deep water operation environment, A new type of wharf named sheet pile wharf with barrier piles was developed, which has been applied more and more in new large wharf construction and reforming construction of existing small wharf in the deep water. Most of the finished researches on this new structure have been focused on the improvement of bearing capacity compared with the traditional sheet pile wharf, but the key problem about the interaction between structures (wall and barrier piles) and soil of sheet pile wharf with barrier piles has not been attached enough importance and investigated systematically. Therefore, the researches on load transfer mechanisms and computation theory on the sheet pile wharf with barrier piles considering the interaction of wall-soil-pile will be made in this subject, by means of model testing in lab, numerical simulation and theoretical analyses. The main contents included in this study are as follows: based on the large scale model test and numerical simulation, the basic characteristics of interaction between structure and soil of the sheet pile wharf with barrier piles will be studied, the load transfer mechanisms of the structure considering the co-work effects of wall-soil-pile will also be investigated in details, and the influences of several factors on the bearing mechanism and the optimization design indexes will also be discussed by contrastive calculating; furthermore, the wall-soil-pile interaction theory on sheet pile wharf with barrier piles considering soil arching effect will be advanced, and the simplified calculation method on quay wall and barrier pile will be proposed as well based on the obtained testing results of physical tests in situ and in lab. The proposed transfer mechanism and calculation theory are helpful to improve scholarly system and spread application of the sheet pile wharf with barrier piles.

随着码头建设向深水化、大型化发展，新型遮帘式板桩码头被越来越多的应用到新建大吨位码头及现有板桩码头深水化改造中。目前已有研究多集中于对比其承载效果的改善与提高，而结构（前墙、遮帘桩）与土相互作用等核心问题研究还未系统开展，因此本课题将采用室内模型试验、数值模拟与理论分析等方法，开展前墙-土体-遮帘桩共同作用下的遮帘式板桩码头承载机理及计算理论研究。拟通过大型室内模型试验和数值模拟，重点揭示遮帘式板桩码头建设过程中结构与土相互作用的承载机理，阐明前墙-土体-遮帘桩共同作用的荷载传递机理及破坏模式，并分析相关因素的影响，提出优化设计指标等；在此基础上，建立考虑土拱效应的遮帘式板桩码头前墙-土体-遮帘桩共同作用理论，并给出求解方法，最后结合原位监测等成果，提出前墙和遮帘桩等主要构件的简化设计计算方法。所得考虑前墙-土体-遮帘桩共同作用的承载机理和计算理论与方法，具有重要的理论意义和工程价值。

随着码头建设向深水化、大型化发展，新型遮帘式板桩码头被越来越多的应用到新建大吨位码头及现有板桩码头深水化改造中。目前这种新型板桩码头结构的科学研究远远落后于工程实践，对其承载特性和变形机制的认识还不完善，特别是对于结构（前墙、遮帘桩）与土相互作用等核心问题研究还未系统开展，因此，开展前墙-土体-遮帘桩共同作用下的遮帘式板桩码头承载机理及计算理论研究，具有重要理论意义和工程意义。本课题密切结合依托工程，采用试验研究、数值模拟与理论分析等方法，开展了以下研究：开展了遮帘式板桩码头结构荷载传递机理室内模型对比试验研究，阐明了遮帘桩在码头前沿开挖和上部结构施工两个阶段的承载机理；进行了遮帘式板桩码头承载和变形特性现场试验研究，对码头结构沉降、水平位移、水位、水平土压力、结构内力等进行了监测与测量，得到了其变形机制和荷载传递特性，揭示了码头结构和土体相互作用的承载特点，证明了遮帘式板桩码头作为新型大型深水板桩码头结构的可行性；开展了遮帘式板桩码头结构与土体相互作用数值模拟研究，研究了桩体尺寸与间距、桩墙间距等重要设计参数对码头承载特性的影响，得出了各参数对码头结构荷载传递的影响规律；基于遮帘式板桩码头结构变形特点，提出考虑结构与土体相互作用的水平土压力计算模型，建立了前墙水平土压力理论计算方法。研究成果为遮帘式板桩码头结构的设计、施工和安全运营提供了科学依据。