The influence of fiber-reinforced shotcrete on the ground settlement in tunnel excavation: A case study of Tabriz metro line ۲

In recent years, as cities expand and populations increase, the importance of public transportation, particularly subways, and underground spaces, has grown. In-situ concreting in underground areas is time-consuming, costly, and requires significant space for molding. However, shotcrete can be applied quickly with high quality and minimal space needed. The main purpose of this study is to investigate the settlement of the ground surface resulting from tunnel excavation using ۳D numerical modelling. This study investigated the use of shotcrete reinforced with recycled and industrial fibers as an alternative tunnel support system in section ۴ of the third phase of Tabriz metro line ۲. The evaluation of the load-carrying capacity of shotcrete-lattice and fiber-reinforced shotcrete support systems showed that the maximum tensile stress for the preferred support systems is ۱۶۵.۱ MPa and ۱.۲۸۴ MPa, respectively. The results of finite element analysis revealed that shotcrete with ۴۰ of industrial steel fibers and ۳۰ of recycled materials can be a viable alternative to the traditional shotcrete-lattice tunnel support system in Tabriz metro line ۲ in terms of resistance and surface settlement properties. The use of recycled fibers is cost-effective, and a smaller quantity of recycled fibers can provide similar mechanical properties compared to a larger quantity of industrial fibers.

کلیدواژه ها:

Numerical Modeling ، recycled fibers ، settlement ، Shotcrete ، tunnel