Title:
Punching-Shear Behavior of Glass Fiber-Reinforced Polymer-Reinforced Precast Concrete Tunnel Segments
Author(s):
Ahmed Elbady, Salaheldin Mousa, Hamdy M. Mohamed, and Brahim Benmokrane
Publication:
Structural Journal
Volume:
121
Issue:
4
Appears on pages(s):
19-34
Keywords:
deflection and strain; glass fiber-reinforced polymer (GFRP) bars; precast concrete tunnel lining (PCTL) segments; punching shear; reinforcement ratio; segment length; shear stirrups; theoretical predictions
DOI:
10.14359/51740709
Date:
7/1/2024
Abstract:
The behavior of precast concrete tunnel lining (PCTL) segments
reinforced with glass fiber-reinforced polymer (GFRP) bars
under punching loads is one area in which no research work has
been conducted. This paper reports on an investigation of the
punching-shear behavior of GFRP-reinforced PCTL segments
induced by soil conditions, such as rock expansion or the geotechnical conditions surrounding a tunnel. Six full-scale rhomboidal PCTL specimens measuring 1500 mm (59 in.) in width and 250 mm (9.8 in.) in thickness were constructed and tested up to failure. The investigated parameters were: 1) reinforcement type (GFRP or steel); 2) reinforcement ratio (0.46 or 0.86%); 3) stirrups as shear reinforcement; and 4) segment length (2100 or 3100 mm
[82.7 or 122 in.]). The experimental results are reported in terms
of cracking behavior, punching-shear capacity, deflection, strain
in the reinforcement and concrete, and failure modes. The results
reveal that the GFRP-reinforced PCTL segment was comparable
with its steel counterpart with the same reinforcement ratio and
satisfied serviceability limits. Increasing the reinforcement ratio
and decreasing the segment length enhanced the punching-shear
strength. The shear stirrups improved the structural performance
and increased the punching and deformation capacities of the
GFRP-reinforced PCTL segments. In addition, theoretical predictions of the punching-shear capacity using the current design provisions were compared to the experimental results obtained herein. The theoretical outcomes show the suitability of using current FRP design provisions for predicting the punching capacity of PCTL segments reinforced with GFRP bars.