Experimental study on the influence of glass fiber reinforced concrete isolation layer on the seismic dynamic response of tunnels

Abstract

The use of isolation layer structures has been a proven and effective method in reducing the seismic dynamic response of tunnels. It is considered a crucial measure in enhancing the seismic capacity of tunnels. This paper focused on the Xianglushan Tunnel Project and investigated the key factors affecting the glass fiber reinforced concrete (GFRC) isolation layer through shaking table tests. The research analyzed the seismic dynamic response characteristics of the lining under varying fiber content, isolation layer thickness, and seismic intensity. According to the test results, the GFRC isolation layer is more effective in reducing the acceleration and strain response of the lining compared to the rubber isolation layer, indicating a superior isolation effect. The shock absorption effect of the GFRC isolation layer is affected by its fiber content. The best effect is achieved when the isolation layer thickness and lining thickness are in the ratio of 1:1 and the GFRC isolation layer contains 0.9 % glass fiber. The thickness of the GFRC isolation layer has an optimal interval, which is directly related to the glass fiber content. The effectiveness of the GFRC isolation layer in reducing seismic impact decreases as the intensity of the earthquake increases. While the GFRC isolation layer cannot alter the way in which the lining deforms or fails during an earthquake, it can help reduce the seismic dynamic response of critical parts of the lining.

Keywords

• Glass fiber reinforced concrete
• Isolation layer
• Tunnel
• Earthquake dynamic response
• Shaking table test