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

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.