Flexural performance of rigid joints for diaphragm walls: Experimental investigation and numerical analysis

Diaphragm walls have been widely applied in long-span suspension bridges due to superior mechanical performance and extensive adaptability to various geological conditions. However, limited studies focused on the structural behaviour of rigid joints for diaphragm walls. This paper hence presented the flexural performance of joints through experimental investigation and numerical analysis. Two types of joints were designed to compare the structural response in terms of failure modes and moment resistance. Parametric analysis was carried out to explore critical parameters that influenced the joint performance significantly. A related provision in a current design code was evaluated to check if it was compatible to predict the moment capacity of designed joints. Results suggested that concrete cracks dominated the moment resistance of joints, and numerical analysis was reliable to predict the damage development as well as the moment-deflection relationship. The joint with U-shaped rebar exhibited more excellent performance that the counterpart with C-T lock. The critical parameters that could affect the member behaviour consisted of reinforcement strength, reinforcement diameter and a distance between tensile reinforcement and beam edge. The current design code provided nonconservative estimations of moment capacity, and thus a reduction factor should be proposed to promote satisfactory application.