向上顶管技术竖井管片密封垫设计及试验研究

Design and Experimental Research on Segment Sealing Gasket of Vertical Shaft Using Upward Pipe Jacking Technology

  • 摘要: 为研究向上顶管竖井施工中预制竖井管片的防水和拼装性能,通过ABAQUS/Explicit对3种截面形式的密封垫进行有限元模拟,分析比较后针对性研制出一款耐水压高、压缩性强的管片密封垫,并依次开展压缩装配试验、水密试验及径向拼装试验,分析密封垫在不同接缝张开量、错台量条件下的物理力学性能。研究结果表明:接缝张开量和错台量与密封垫防水性能呈负相关关系,为达到防水压力设计值0.8 MPa,管片接缝张开量须保持在6 mm以内,错台量控制在10 mm以内;径向拼装时密封垫纵向变形近似呈弓形,即中间变形最大,两侧逐渐缩小,拼装时应注意挤压变形引起的错台问题;径向拼装推进力与接缝张开量呈负相关关系,为满足防水性能和拼装变形控制要求,可考虑采用扩径拼装方式,管片块间预设的张开量应大于9 mm。

     

    Abstract: In order to study the waterproof and assembly performance of prefabricated vertical shaft segments in upward pipe jacking construction, finite element simulations of sealing gaskets with three different cross-sectional forms were performed using ABAQUS/ Explicit. After comparison and analysis, a sealing gasket with high water pressure resistance and strong compressibility was specifically developed. Compression assembly tests, water-tightness tests, and radial assembly tests were conducted sequentially to analyze the physical and mechanical properties of the sealing gasket under different joint opening and misalignment conditions. The results show that the joint opening and misalignment are negatively correlated with the waterproof performance of the sealing gasket. To achieve the designed waterproof pressure value of 0.8 MPa, the joint opening should be kept within 6 mm, and the misalignment should be controlled within 10 mm. During radial assembly, the longitudinal deformation of the sealing gasket is approximately in arc-shape, with the maximum deformation at the center and gradually decreasing at the sides. Attention should be paid to misalignment caused by squeezing deformation during assembly. The radial assembly thrust is negatively correlated with joint opening. To meet the waterproof performance and assembly deformation control requirements, an expanding diameter assembly method can be considered, with the pre-set joint opening between the segments greater than 9 mm.

     

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