Interfacial behavior of permeable polymer and concrete at joints of cross-river shield tunnels

Joint leakage is one of the main diseases of shield tunnels crossing rivers during operation. The bonding performance with joint concrete and commonly used grouting materials in shield tunnel engineering is poor. The effects of common materials used for leakage treatment are limited. The authors has developed a new type of permeable polymer based on the existing grouting materials. A series of tests are carried out to investigate the applicability of the new permeable polymer for joint leakage treatment of tunnels. A theoretical model for the interface between the permeable polymer and the concrete is established and validated. The main conclusions are as follows: the interfacial shear strength between the permeable polymer and the concrete segments is directly proportional to the interfacial roughness and normal stress, and inversely proportional to the degree of humid condition of tunnels. The degree of influences of various factors on the interfacial strength is normal pressure > interfacial roughness > interfacial humidity. The residual error of linear regression theoretical model for the shear strength of interface between the polymer and the segment concrete obeys the normal distribution. The shear strength of the interface between the permeable polymer and the concrete can reach up to 1.5 MPa. The permeable polymer meets the needs of leakage treatment in cross-river shield tunnels.