Full scale tests and a progressive failure model to simulate full mechanical behavior of concrete tunnel segmental lining joints

Abstract

In the context of segmental concrete linings for tunneling, segmental joints are the most vulnerable parts of the lining. Most existing segmental joint models cannot evaluate the full mechanical behavior of segmental joints from the elastic deformation to the inelastic damage and failure. However, in some actual field cases, segmental joint damage and failure can occur. In this study, full-scale tests on the segmental joint adopted by a gas transmission tunnel are presented. The segmental joint is continuously loaded until it reaches its ultimate capacity. The internal force, deflection and failure characteristics of the segmental joint during the loading process are reported and compared with those of previous studies tested with flat segments. The relationships between the internal force, deflection and damage to the segmental joint are systematically analyzed. The tests reveal that the full mechanical behavior of the segmental joints can be divided into three progressive phases with four critical points. Based on the test observations, a progressive failure model that consists of a multiple stress states is proposed to simulate the full mechanical behavior of the segmental lining joints. The proposed model is ultimately compared with the full-scale test results.