Studying the Behavior of Strengthened Four Shapes of RC Tunnels using Externally Bonded GFRP

Dr. Eiad Hafiz Zahran

Strengthening of reinforced concrete members by externally bonded fiber reinforced polymers (FRP) sheets or plates has been increasing in recent years due to the beneficial characteristics of being non-corrosive and generally resistant chemicals, high strength to weight ratio, and non-magnetic and non-conductivity of composite materials. The experimental results showed that better performance of the strengthened sections with GFRP could be achieved in terms of ultimate load, crack control, and stiffness. Application of GFRP to strengthen underground tunnels is one of the prime applications due to the severe environment, which the concrete is exposed. Repair work of underground tunnels such as "Ahmed Hamdi Tunnel under Suez Canal "or" El-Salam Tunnel under Suez Canal" is carried out mainly to strengthen the primary lining of the tunnel due to any defects or cracks. Experimental program contain four shapes of concrete tunnel "Circular section, Elliptical section, Egg-Shaped section and Horse shoie section"  to investigate of the research work showed that the procedure described in this paper is stable, fast in convergence and effective for tunnels applications.