3D numerical study of the joint dislocation and spacing impacts on the damage of tunnel segmental linings

Abstract

Aggravating factors of the segmental tunnel lining damage can severely affect the performance of support systems. Based on previous studies and statistical data, the excessive thrust force, offset, and gap are the essential factors that can aggravate the damage of segmental linings during the thrust force application stage. This study aims to evaluate the effect of influential factors, including longitudinal offset, circumferential offset, incomplete contact of loading shoes, and incomplete contact in the support area. To evaluate the impact of these defects and compare the numerical results, crack width, crack starting force, allowable crack force, plastic strain, and damage parameters were considered. In addition, the impact of mentioned factors is evaluated on the performance of three different segmental lining types, including reinforced concrete segment, recycled steel fiber reinforced concrete segment, and ultra-high performance recycled steel fiber reinforced concrete segment. In this parametric study, the parameters' values were selected based on statistical data of more than 23,000 installed segments. According to the results, it can be said that numerical modeling is able to simulate stress and damage patterns in different conditions accurately. This method can also provide helpful information about the performance of segmental tunnel lining because the repetition of the classical design often uses very simple models, which ignore essential phenomena such as the effect of longitudinal or circumferential offset, incomplete contact of the shoe loading, or in the support area, and excessive thrust force. Numerical analysis of segmental tunnel lining behavior by considering different conditions can reduce undesirable phenomena and, consequently, construction costs.