New American Concrete Institute (ACI) Code for Design, Manufacturing and Construction of Tunnel Segmental Lining

Abstract

American Concrete Institute (ACI) as one of the most powerful advocates for concrete construction in the world is aiming to publish its first guide (ACI 533.2R) led by the authors of this paper on general aspects of precast tunnel segments. This paper is intended to present salient features of the guide including the most recent developments on all aspects of design, manufacturing and construction. This document is drafted based on the knowledge and the experience gained on projects in Asia, Europe, and North America, and available national and international reports and recommendations. Procedures to perform structural design for Ultimate and Serviceability Limit States (ULS, SLS) during production, transportation, construction and final service stages are explained. Details of segmental ring geometry and systems, concrete strength, curing, and reinforcement detailing are discussed. Gasket design, segment connection devices, anchorage systems, tolerances, measurement and dimensional control, and repair of defects are among other topics that are presented. This document also addresses testing and performance evaluation, durability and degradation mechanisms of tunnel linings and their mitigation methods. While some design parts of this guide may only consider the procedures adopted by ACI, they can be extended to other national and international codes and used worldwide.