Course Length: 1.5 Hours

The evaluation and retrofit of buildings with unreinforced masonry (URM) brick bearing walls is a significant part of the ongoing effort to improve the existing structures in areas subject to earthquake hazard. This webinar introduces the requirements of Chapters 11 - Masonry, 13 - Architectural, 15 - System-Specific Performance Procedures, and 16 - Evaluation Checklists of ASCE 41-13 “Seismic Evaluation and Retrofit of Existing Buildings” for URM brick bearing wall buildings. The new standard provides a unified method for evaluating and retrofitting existing buildings for earthquakes and eliminates significant inconsistencies between the two previous standards.

Purpose and Background

URM brick bearing wall buildings are consistently one of the most vulnerable building types and are common candidates for seismic evaluations and retrofits. Performance of previously retrofitted URM buildings has been mixed, but thorough retrofits with effective enforcement and quality assurance can significantly reduce the risks of collapse and falling components. This webinar will familiarize participants with common considerations including documenting the conditions of unreinforced masonry bearing walls, options for analysis, and design of enhancements.

Primary Discussion Topics

• Documenting the condition of unreinforced masonry building components
• Determining material properties
• Masonry condition enhancement
• Establishing quality assurance plans for anchors in unreinforced masonry walls
• Linear and nonlinear analysis alternatives
  

Learning Outcomes 

• Describe seismic vulnerabilities common to unreinforced masonry buildings
• Familiarize participants with the major unreinforced masonry provisions in Chapters 11, 13, 15, and 16 of ASCE 41-13
• Case study: a simple URM building, showing a Tier 1 Seismic Evaluation and a System-Specific Retrofit using linear analysis
• Summarize the potential benefits of more-detailed nonlinear analyses
  

Webinar Benefits

• Gain confidence in helping building owners manage seismic risks posed by URM buildings
• Find out about the extensive changes to the URM requirements which are now distributed throughout ASCE 41
• Zero in on and avoid missing major requirements that apply to URM buildings
• Find out how ASCE 31-03 seismic evaluation requirements for URM buildings have been merged into ASCE 41-13
• Gain familiarity with a sample URM building evaluation and retrofi
• Improve judgment about the importance of thorough materials testing and quality assurance procedures
• Learn the importance of insights provided by the standard’s commentary and references
  

Intended Audience

• Civil and Structural Engineers with an emphasis on existing buildings
• Building officials
• Building Managers
• Architects
• Federal and State Agencies
• Building materials testing specialists
  

Webinar Outline 

• Describe common seismic vulnerabilities of unreinforced brick masonry bearing wall buildings. 
• Summarize the results of a typical seismic evaluation based on checklists that apply to unreinforced masonry (URM) buildings in ASCE 41 Chapter 16. 
• Summarize provisions in Chapters 11 and 13
• Documenting the condition of URM buildings per Chapters 3,4, and parts of 5 and 6
• Testing for material properties
• Enhancing the condition of URM 
• Quality assurance for anchors
• General evaluation and retrofit requirements with an emphasis on linear analysis procedures. 
• Summarize System-Specific Procedures for retrofitting URM buildings with flexible wood floors and roofs in Chapter 15. 
• Provide a simple, two-story URM building case study
• Apply the requirements of Chapters 16, 11, 13, and 15. 
• Provide examples of where information in the commentary and other referenced sources can be helpful to users of the standard.
• List the potential benefits of nonlinear analyses provisions in Chapter 13 compared to the linear analysis for URM bearing wall buildings