【作者】 周学领；

【导师】 廖少明；

【作者基本信息】 同济大学 ， 岩土工程， 2007， 硕士

【摘要】 目前，钻孔咬合桩在我国越来越多地得到应用，但大部分只是作为临时结构使用，在基坑开挖完成后即废弃，经济上造成很大的浪费，也对后续的地下空间开发利用形成障碍。考虑到咬合桩的结构形式和受力机理同地下连续墙相似，那么咬合桩应该可以像地下连续墙一样作为永久结构使用。基于这样的观点，本文结合上海地铁某咬合桩试验段工程，对咬合桩作为永久结构使用的咬合桩复合结构设计理论和方法进行了研究。 首先，文章详细介绍了目前咬合桩结构设计理论和方法在我国的应用和研究情况，目前国内现在咬合桩技术的研究主要针对施工技术进行研究，针对咬合桩复合结构的设计方法的研究较少。 其次，对咬合桩作为挡土结构使用时设计中应考虑的关键参数进行了研究，根据咬合桩成桩施工的垂直度和咬合面的受力破坏特点提出了合理咬合量的计算方法，同时对不同搭配形式咬合桩的刚度计算及截面配筋设计方法进行了研究。 随后，研究了不同搭配形式咬合桩作为主体结构使用的可行性，认为荤荤搭配的咬合桩可以作为主体结构一部分使用，但荤素搭配的咬合桩作为主体结构一部分使用要控制素桩的裂缝发展。研究了咬合桩复合结构的共同作用模式和与主体结构的结合方式，给出了不同复合结构形式下的设计原则，讨论了刚度比、地基刚度和咬合桩止水性等因素对内力荷载分担的影响。同时对咬合桩复合结构的抗裂控制进行了研究，并对上海地铁咬合桩试验段的咬合桩、内衬墙和咬合面进行了抗裂验算，提出了荤素搭配咬合桩作为复合结构使用需要结合内衬墙使用。 再次，研究了通过工程实测数据推算咬合桩及内衬结构弯距的方法，咬合桩弯距推算有根据钢筋应力推算及测斜数据推算两类。同时应用以上推算方法对上海地铁咬合桩试验段的咬合桩与主体结构的内力及共同作用进行了实测分析，认为咬合桩在使用阶段仍分担相当一部分水土压力荷载，内衬墙的内力分担逐步增加，给出了实测的内力分担比，两者的共同作用效果明显。 最后，研究了咬合桩复合结构的构造设计，研究了不同咬合桩复合结构形式的防水构造设计要点，并对不同复合结构形式下的咬合桩与主体结构(楼板、侧墙)连接的可行方案进行了探讨。更多还原

【Abstract】 Currently, secant pile wall is mostly used as temporary structure in China, it is a uneconomic way that the secant pile wall is abandoned after excavation, at the same time, the abandoned pile wall is a big obstruct to the subsequent development of urban underground space. Structural style and bearing mechanics of secant pile wall are similar to the diaphragm wall and should be used as both temporary and permanent structure like the diaphragm wall. Based on the previous viewpoints and the testing project of Shanghai Metro, the research on the theory and design method of the secant pile wall composite structure used as permanent structure is studied in the paper.Firstly, the paper introduces the existing conditions of application and research in our country, and they are still in the stage of familiar with and exploring construction methods. The research on design method of the secant pile is little.Secondly, the key parameters of secant pile designed as retaining wall is analyzed in the paper. Based on the squareness of the secant pile boring and destruction feature of secant pile face, the paper delivers the calculation method of proper overlapping size of secant pile wall. The calculation method of rigidity and reinforcement of different secant pile format is also studied.Then, the paper discusses the feasibility of different secant pile wall used as permanent structure and includes that the hard/hard secant pile wall can be used as permanent structure and hard/firm as a part of permanent structure, the joints between secant pile wall and the exterior wall of the major structure are also presented. The paper qualitative discusses the additive condition of the load moment and stress on the lining and exterior wall and presents the design items needed attention under the different combination format. The paper also discussed the influence of stiffness ratio、 subgrade modulus and waterproofing quality to the internal force and load sharing. Based on the study of crack resistance of secant pile wall, the paper takes checking calculation to the testing project of Shanghai Metro and advises that hard/firm secant pile wall should used with lining.And then, the inverse calculation method of bending moment of secant pile and lining based on the measured stress of reinforcement and lateral deformation is studied. The inverse calculation method is applied to analyze the internal force and interaction of lining and secant pile wall of the testing project of Shanghai Metro. The更多还原