Using Nonlinear Simulation to Analyze the Bearing Performance and Engineering Application of Partial Strengthening and Replacement Composite Shear Walls Without Support Roof

With the advancement of construction development, urban renewal, and urbanization, engineering appraisal and structural reinforcement will become crucial tasks in the construction industry, thus presenting both significant challenges and long-term responsibilities. The concept of “partial strengthening and replacement composite shear walls without support roof” refers to a structural system that utilizes the existing load-bearing capacity of RC shear walls. In this method, high-performance materials are used to locally remove and replace critical load-bearing sections of the wall to be strengthened, resulting in a “composite shear wall” structure composed of both strengthened replacement areas and non-replaced sections. This study proposes the concept of composite shear walls, conducts simulation analysis and exploratory research on their bearing performance, and explores engineering applications based on engineering examples. The research conclusions include the following: Compared to only one batch of replacement reinforcement, partial strengthening and replacement in batches can significantly improve the bearing performance of composite shear walls. The use of steel-reinforced concrete for local strengthening and replacement can significantly improve the bearing performance of composite shear walls, and the magnitude of the improvement in bearing performance decreases with the increase in the initial vertical stress level of the components. The overall structural stress condition after local strengthening and replacement reinforcement is good, and its vertical and horizontal bearing capacity can meet the original design requirements (after reinforcement, the vertical bearing capacity of the overall structure increased by about 6.3% compared to the original design, and the horizontal ultimate bearing capacity is about 1.4 times larger compared to the elastic–plastic “large earthquake” effect of the original design). Compared with conventional replacement methods, the unsupported-roof local reinforcement replacement method has the advantages of using high-performance materials, reducing reinforcement engineering, minimizing resource waste, and simplifying construction procedures, and has good application prospects.