Shear behavior of deep beam with web openings and reinforced with strut reinforcement: a numerical study

Abstract

This study aims to predict the shear behavior of Deep Beams (DB) with web openings and reinforced by struts. ABAQUS Finite Element (FE) program was used to investigate the effects of the type, dimensions, number, and position of the opening, additional reinforcement in the same direction as the strut reinforcement (AS), and Additional Vertical and Horizontal reinforcements (AVH) around the web opening on the shear behavior of the DB. The FE study results showed that the web opening had a significant effect on the shear behavior of DBs reinforced with strut reinforcement, especially for DBs with rectangular opening cuts half of the strut reinforcement. As a result of web openings cutting half or all of the strut reinforcement, the shear capacity of the DB at supports must also be taken into account. The addition of AS improved the ultimate capacity of the deep beam with a small web opening area; otherwise, it showed an insignificant effect on the varying web openings. Adding AVH around the web openings for DBs with rectangular web openings cuts half of the strut reinforcement improved the ultimate capacity and load distribution at support close to the web opening. However, the square openings that cut off all the strut reinforcements had a minor effect. Different proposed equations were provided to predict both the shear strength of the strut with the web opening and the ultimate shear strength of DB with varying web opening cut full/half of the strut reinforcement. Both struts acting as columns and the suggested equations can be used to predict the design shear strength and ultimate capacity of deep beams with web openings and reinforced with strut reinforcement, according to a comparison with the ACI318 formula and the FE result.