Sealing Performance of Prestressed Steel Tube–Concrete Pipe Connection

Abstract In order to study the sealing performance of the joint of a prestressed concrete cylinder pipe (PCCP), this paper established a refined three-dimensional solid finite-element model including the socket steel ring, rubber ring, and bearing steel ring using LS-DYNA nonlinear finite-element software. The influence of internal water pressure, rubber ring type, and connection strength on the sealing performance of the pipeline was explored; at the same time, theoretical calculations were used to investigate the sealing ring performance under the influence of material aging. The results showed the following. (1) When the internal water pressure is less than 3 MPa, the structure has good waterproof sealing performance; when the internal water pressure reaches 3 MPa, the rubber ring leaks. (2) The type of rubber has a significant impact on the stress of the sealing ring, and multiple factors need to be considered when the rubber type is selected. (3) Once an external force acts on the interface, when the external force reaches 169 KN, the displacement reaches 14 mm, and plastic slip displacement begins to occur at the interface; when the force at the connection port reaches 450 KN, the displacement can reach 169 mm, and the structure completely loses its seal. (4) The main factor causing seal ring failure during aging is that after more than 50 years, the sealing performance of hard rubber deteriorates rapidly and reaches a complete failure state. The results indicate that polyisoprene rubber, natural rubber, and hard rubber all have certain sealing strength, but hard rubber has a poor waterproof effect. During the construction and installation of PCCP, attention should be paid to the stress situation at the connection port. This study can provide a reference for pipeline design.