Design Philosophy
- Building code requirements for masonry structures.
- 1992 ACI 530-92/ASCE-92/TMS402-92 Building Code Requirements for masonry structures.
- Often called the 530 code or the MSJC code.
- Where MSJC = Masonry Standards Joint Committee with members from:
- ACI - American Concrete Institute.
- ASCE - American Society of Civil Engineers
- TMS - The Masonry Society
- CMR - Council for Masonry Research.
- Developed a single standard that was mechanics-based for both clay and concrete masonry.
- Working Stress Design Philosophy.
- In this class we will use the older Working Stress Design (WSD) approach that is also known as Allowable Stress Design (ASD).
- This approach is still the most appropriate for wood and masonry, even though both industry groups have made attempts to develop strength procedures.
- This author believes, however, that these strength efforts are still at the development stage and will not be readily used by the design community for some time yet.
- The basic WSD approach is:
- Straight - line, elastic stress assumption (the induced-stresses are within the linear, elastic range of the material's behavior)
Actual stress £ Allowable stress ß ß Stress developed in a structural member due to actual (service or working) loads. A function of the material's strength and behavior for that particular stress under consideration.
- Design methodology for masonry - an introduction
- The 1933 Long Beach, California earthquake demonstrated that unreinforced masonry structures designed by empirical
procedures could not adequately resist the induced tensile stresses caused by seismic loadings.
- The impetus for developing a rational procedure for reinforced masonry.
- An elastic WSD procedure for masonry appeared in the 1937 UBC.
- Modern reinforced masonry uses:
- Steel to resist shear and tensile stresses.
- Also adds ductility to the system.
- Masonry to resist compressive stresses.
- Also contribute to weather durability fire protection, and stability.
- Steel to resist shear and tensile stresses.
- The 1933 Long Beach, California earthquake demonstrated that unreinforced masonry structures designed by empirical
procedures could not adequately resist the induced tensile stresses caused by seismic loadings.
