沉管隧道节段接头剪力键受力特性及作用机理研究

发布时间：2018-05-08 01:03

本文选题：沉管隧道 + 节段接头　；参考：《长安大学》2014年硕士论文

【摘要】：随着我国跨海越江沉管隧道的不断修建，沉管法施工得到足够的重视，理论技术不断进步。当前修建超长沉管隧道多采用节段式管节取代整体式管节，可避免因温度变化差异、施工差异、混凝土内部应力过大等原因引起混凝土管节出现开裂的情况。国内外试验主要是针对沉管隧道中间接头和最终接头的研究，对节段接头的构造形式、受力特性、作用机理及剪力承担比等方面的研究尚少。本文以港珠澳海底沉管隧道工程为依托，对在荷载作用综合组合的不利情况下，采用理论研究、三维数值模拟和大比尺模型试验综合的手段对节段接头剪力键的破坏形式、破坏原因、应力发展趋势、危险敏感区域分析及剪力键的作用机理进行研究。第一，模型试验前，根据沉管隧道管节所受主要荷载作用确定由纵向地基刚度差异和不均匀回淤荷载引起弯曲工况和横向地基刚度差异和不均匀回淤荷载引起扭转工况，建立足尺三维数值模拟来模拟实际工程，分析沉管节段接头的力学性能并为物理模型试验提供指导。第二，以长安大学路基沉降平台为基础，按试验要求进行平台改造，，制定模型试验实施的总体方案，开展了在陆域条件下沉管管节结构与周边土体相互作用的大比尺模型试验，并解决了试验中遇到的技术难题。建立完全模拟模型试验的缩尺数值模拟，并与模型试验的分析结果进行对比研究，建立起缩尺数值模拟和模型试验之间的桥梁。第三，采用缩尺数值模拟和模型试验相结合的手段，阐述节段接头剪力键在弯曲和扭转工况下的破坏形式、破坏原因、应力发展趋势，对剪力键危险敏感区域进行分析并提出剪力键应该着重加强的区域，最后从上述几方面综合揭示了剪力键的作用机理，相关结论对我国在建及拟建海底沉管隧道工程设计与研究具有一定的借鉴意义。
[Abstract]:With the continuous construction of cross-sea and cross-river immersed tunnel in China, enough attention has been paid to the construction of sinking pipe method, and the theory and technology have been improved constantly. In order to avoid cracking of concrete pipe joints due to temperature variation, construction difference and excessive internal stress of concrete, segmental pipe segments are often used to replace integral pipe joints in the construction of ultra-long immersed tube tunnels at present. The domestic and foreign tests mainly focus on the research of intermediate joint and final joint of immersed tube tunnel, but there are few studies on the structural form, mechanical characteristics, action mechanism and shear bearing ratio of segmental joint. In this paper, based on the undersea sinking tunnel project of Hong Kong, Zhuhai-Macao, and under the unfavorable condition of comprehensive combination of loads, the failure form of shear bond of segmental joint is analyzed by means of theoretical research, three-dimensional numerical simulation and large scale model test. Failure cause, stress development trend, hazard sensitive region analysis and mechanism of shear bond are studied. First, before the model test, according to the main loads on the pipe joints of the immersed tube tunnel, the bending condition and the torsional condition caused by the longitudinal foundation stiffness difference and the uneven siltation load are determined, and the lateral foundation stiffness difference and the uneven siltation load cause the torsion condition. A full-scale three-dimensional numerical simulation was established to simulate the actual engineering, to analyze the mechanical properties of the joints of the immersed pipe and to provide guidance for the physical model test. Secondly, based on the subgrade settlement platform of Changan University, the platform is reformed according to the test requirements, the overall scheme of model test is formulated, and the large scale model test of interaction between pipe joint structure and surrounding soil is carried out under the condition of land area. The technical problems encountered in the experiment are solved. The scale numerical simulation of complete simulation model test is established and compared with the analysis result of model test. The bridge between scale numerical simulation and model test is established. Thirdly, by means of scale numerical simulation and model test, the failure form, failure cause and stress development trend of segmental joint shear bond under bending and torsional conditions are expounded. This paper analyzes the dangerous sensitive region of shear bond, and puts forward the region where shear bond should be strengthened. Finally, the mechanism of shear bond is comprehensively revealed from the above several aspects. The conclusions can be used for reference in the design and study of submarine tunnel under construction in China.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U459.5

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