STP871: Guidelines for Temporary Masonry Wall Support Systems

    Carr, RI
    Professor of Civil Engineering, University of Michigan, Ann Arbor, MI

    Woods, RD
    Professor of Civil Engineering, University of Michigan, Ann Arbor, MI

    Heslip, JA
    Executive vice-president, National Concrete Masonry Association, Herndon, VA

    Pages: 12    Published: Jan 1985


    Abstract

    Masonry walls are vulnerable to high winds until supported by the completed structure. A common method of temporary support consists of inclined braces restrained at the ground with stakes. Adequate information on the capacity of stakes in this system could not be found in the literature, so research was conducted on the horizontal capacity of stakes in soil. Three stakes were studied: 3.8 by 3.8 cm (2 by 2 in.) and 3.8 by 8.9 cm (2 by 4 in.) wood stakes, and No. 6 reinforcing bars. Each stake was tested at two embedments, 30 cm (12 in.) and 45 cm (18 in.), and at three inclinations to the horizontal, 90°, 60°, and 45°. Stakes were tested in sand, silt, and clay at three consistencies. Loads were applied with a hand-cranked screw mechanism with a proving ring to measure load. Displacement and rotation were measured with two dial gages. A total of 139 tests were performed, and load deflection curves were analyzed at ground level displacements of 3.2 mm (⅛ in.) and 6.4 mm (¼ in.). Equations based on the theory of subgrade reaction for the soils and rigid behavior of the stakes were formulated to match measured data. For most soils, the stake capacity was found to be insufficient to support reasonable lengths of tall masonry walls in a modest wind, 56 km/h (35 mph); consequently, stakes are not recommended as the horizontal support element for tall masonry walls.

    Keywords:

    masonry, wind (meteorology), walls, stakes


    Paper ID: STP34550S

    Committee/Subcommittee: C12.02

    DOI: 10.1520/STP34550S


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