Description
This standard provides retrofit and rehabilitation criteria for reinforced concrete buildings based on results from the most recent research on the seismic performance of existing concrete buildings. The intent of this standard is to provide a continuously updated resource document for modifications to Chapter 10 of ASCE 41-17, similar to how the National Earthquake Hazards Reduction Program (NEHRP) Recommended Seismic Provisions produced by the Federal Emergency Management Agency (FEMA) (FEMA 450) have served as source documents for the International Building Code (IBC) and its predecessor building codes. Specifically, this version of ACI 369.1 serves as the basis for Chapter 10, “Concrete,” of ASCE 41-17.
This standard should be used in conjunction with Chapters 1 through 7 of ASCE 41-17. Chapter 1 of ASCE 41-17 provides general requirements for evaluation and retrofit, including the selection of performance objectives and retrofit strategies. Chapter 2 of ASCE 41-17 defines performance objectives and seismic hazards. Chapter 3 of ASCE 41-17 provides the requirements for evaluation and retrofit, including treating as-built information and selecting the appropriate screening procedures. Chapter 4 of ASCE 41-17 summarizes Tier 1 screening procedures, while Chapters 5 and 6 summarize Tier 2 deficiency-based procedures and Tier 3 systematic procedures for evaluation and retrofit, respectively. Chapter 7 of ASCE 41-17 details analysis procedures referenced in ACI 369.1, including linear and nonlinear analysis procedures, acceptance criteria, and alternative methods for determining modeling parameters and acceptance criteria. Chapter 8 of ASCE 41-17 provides geotechnical engineering provisions for building foundations and assessment of seismic-geologic site hazards. References to these chapters can be found throughout the standard. The design professional is referred to FEMA 547 for detailed information on seismic rehabilitation measures for concrete buildings. Repair techniques for earthquake-damaged concrete components are not included in ACI 369.1. The design professional is referred to FEMA 306, FEMA 307, and FEMA 308 for information on evaluation and repair of damaged concrete wall components.
This standard does not provide modeling procedures, acceptance criteria, and rehabilitation measures for concrete-encased steel composite components. Future versions will provide provision updates for concrete moment frames and will add provisions for concrete components and systems omitted in the present version of the standard.
Table of Contents
PREFACE
INTRODUCTION
CHAPTER 1—GENERAL
1.1—Scope
CHAPTER 2—MATERIAL PROPERTIES AND CONDITION ASSESSMENT
2.1—General
2.2—Properties of in-place materials and components
2.3—Condition assessment
2.4—Knowledge factor
CHAPTER 3—GENERAL ASSUMPTIONS AND REQUIREMENTS
3.1—Modeling and design
3.2—Strength and deformability
3.3—Flexure and axial loads
3.4—Shear and torsion
3.5—Development and splices of reinforcement
3.6—Connections to existing concrete
3.7—Retrofit measures
CHAPTER 4—CONCRETE MOMENT FRAMES
4.1—Types of concrete moment frames
4.2—Reinforced concrete beam-column moment frames
4.3—Post-tensioned concrete beam-column moment frames
4.4—Slab-column moment frames
CHAPTER 5—PRECAST CONCRETE FRAMES
5.1—Types of precast concrete frames
5.2—Precast concrete frames expected to resist seismic forces
5.3—Precast concrete frames not expected to resist seismic forces directly
CHAPTER 6—CONCRETE FRAMES WITH INFILLS
6.1—Types of concrete frames with infills
6.2—Concrete frames with masonry infills
6.3—Concrete frames with concrete infills
CHAPTER 7—CONCRETE STRUCTURAL WALLS
7.1—Types of concrete structural walls and associated components
7.2—Reinforced concrete structural walls, wall segments, and coupling beams
CHAPTER 8—PRECAST CONCRETE STRUCTURAL WALLS
8.1—Types of precast structural walls
8.2—Precast concrete structural walls and wall segments
CHAPTER 9—CONCRETE BRACED FRAMES
9.1—Types of concrete-braced frames
9.2—General
9.3—Stiffness of concrete braced frames
9.4—Strength of concrete-braced frames
9.5—Acceptance criteria for concrete-braced frames
9.6—Retrofit measures for concrete-braced frames
CHAPTER 10—CAST-IN-PLACE CONCRETE DIAPHRAGMS
10.1—Components of cast-in-place concrete diaphragms
10.2—Analysis, modeling, and acceptance criteria for cast-in-place concrete diaphragms
10.3—Retrofit measures for cast-in-place concrete diaphragms
CHAPTER 11—PRECAST CONCRETE DIAPHRAGMS
11.1—Components of precast concrete diaphragms
11.2—Analysis, modeling, and acceptance criteria for precast concrete diaphragms
11.3—Retrofit measures for precast concrete diaphragms
CHAPTER 12—CONCRETE FOUNDATIONS
12.1—Types of concrete foundations
12.2—Analysis of existing concrete foundations
12.3—Evaluation of existing condition
12.4—Retrofit measures for concrete foundations
CHAPTER 13—NOTATION AND DEFINITIONS
13.1—Notation
13.2—Definitions
REFERENCES
Authored references