ACI 347.2R

Abstract

Although the aforementioned documents provide basic guidelines for general formwork operations, there are no codes or standards that provide detailed design and construction requirements specifically for shoring/reshoring operations for multistory reinforced and post-tensioned concrete construction. Investigations for usable procedures to establish safe and cost-effective shoring/reshoring operations have been ongoing for several decades. These investigations focus on two major areas: 1) determining the distribution of loads carried by the concrete structure during construction; and 2) estimating the ability of the concrete members to resist construction loads. This guide outlines the importance of appropriate shoring/ reshoring design for multistory structures and provides basic requirements for safe construction. ACI SP-4 serves as an expanded commentary to ACI 347R and provides detailed information related to formwork practices, including a discussion of shoring/reshoring procedures and analysis examples. Contract documents or the authority having jurisdiction may require the contractors to supply to the building official, upon request, the structural analysis and concrete strength requirements used in planning and implementing shoring/reshoring operations. Such data and information should be furnished to the engineer/architect who should evaluate the effects of construction loads on the immediate and long-term deflections. The contractors and formwork designers should acquire an understanding of the construction loads and the structural behavior of the buildings during construction. This understanding enables them to develop a rational shoring/reshoring system design that is economical without compromising safety, quality, and serviceability. The objective of this guide is to present practical guidelines for the design of shoring/reshoring operations. This guide provides tools to design and evaluate construction schedules for shoring/reshoring of multistory reinforced and post-tensioned concrete structures.