Evaluation of environmental and economic compatibility of different types of segment linings based on the structural performance with some aggravating factors

Abstract

The performance of supporting systems can be significantly affected by aggravating factors that contribute to segmental tunnel lining damage. Based on previous studies and statistical data, the excessive thrust force and defect in support conditions are the crucial factors that can aggravate the damage of segmental linings during the installation stage. This study aims to evaluate the effect of influential factors, including the excessive thrust force, the incomplete contact of loading shoes, configuration of loading shoes, defect gap thickness, and segment type. In addition, a series of numerical simulation are performed to investigate the impact of the influential factors on the performance of three different segmental lining types, including conventional reinforced concrete segment, recycled steel fiber reinforced concrete segment, and new hybrid design recycled steel fiber reinforced concrete segment. The results indicated that numerical modeling can accurately simulate stress concentration and damage patterns of segmental lining in different conditions. This method can provide useful information about the performance of segmental tunnel linings, considering essential phenomena that are neglected in traditional design methods, such as the effect of incomplete contact of the support area, and the thickness of circumferential gap. Numerical analysis of segmental tunnel lining behavior by considering different conditions can help reduce undesirable consequences and construction costs. The results indicated that the increase in the thickness of the gap significantly increase in crack opening and destructive damages. While, the configuration of the loading shoes affects the amount of crack openings, the number and position of these cracks; the effect of this parameter is very lower compared to the presence of defects in the supporting area. Finally, it was concluded that the hybrid design showed high efficiency for all investigated conditions, in terms of structural performance, environmental impact and economic compatibility.