Description
Abstract
This standard defines procedures that may be used to design special precast concrete shear walls, coupled or uncoupled, composed of discretely jointed precast panels that are vertically post-tensioned to the foundation with unbonded tendons. Such walls are suitable for use in regions of high seismicity and for structures assigned to high seismic design categories. After a major seismic event, these walls can be expected to exhibit minimal damage in the flexural hinging region at the base of the wall as well as negligible permanent displacements. Such walls do not satisfy the prescriptive requirements of Chapter 18 of ACI 318-14 for shear walls of monolithic construction. According to 18.2.1.7 of ACI 318-14, their acceptance requires demonstration by experimental evidence and analysis that the walls have strength and toughness equal to or exceeding those provided by comparable monolithic reinforced concrete walls that satisfy the prescriptive requirements of Chapter 18. This standard describes the procedures that the designer may use to demonstrate, through analysis, that one type of unbonded post-tensioned precast wall has strength and toughness at least equal to that of comparable special reinforced concrete monolithic walls. The standard consists of Design Requirements and a Commentary.
Keywords:
coupling devices; drift angle; energy dissipation; lateral resistance; post-tensioning; precast concrete; prestressed concrete; seismic design; special shear wall; test module; toughness.
Table of Contents
Chapter 1—General, p. 2
1.1—Introduction
1.2—Scope
1.3—Drawings
Chapter 2—Notation and definitions, p. 5
2.1—Notation
2.2—Definitions
Chapter 3—Referenced standards and reports, p. 7
Chapter 4—Materials, p. 8
4.1—General
4.2—Ducts
4.3—Reinforcement
4.4—Concrete
4.5—Interface grout
4.6—Coupling devices
4.7—Corrosion protection of prestressing tendons
Chapter 5—Structural system requirements for walls, p. 9
5.1—General
5.2—Strength
5.3—Drift
5.4—Wall characteristics
5.5—Distribution of walls within structures
5.6—Wall system-gravity load frame interactions
Chapter 6—Design requirements for uncoupled wall systems, p. 12
6.1—Scope
6.2—Materials
6.3—Prestress force
6.4—Energy-dissipating reinforcement
6.5—Shear strength
6.6—Flexural strength and drift limits
6.7—Detailing of lowermost wall panel
6.8—Interface grout
Chapter 7—Design requirements for coupled wall systems, p. 16
7.1—Scope
7.2—Materials
7.3—Coupling devices
7.4—Prestress force
7.5—Shear strength
7.6—Flexural strength and drift limits
7.7—Lowermost panel
7.8—Interface grout
Chapter 8—Design requirements for coupling devices, p. 18
8.1—Scope
8.2—General
8.3—Materials
8.4—Design methodology
Chapter 9—Commentary references, p. 20