Shoring and bracing are essential parts of many masonry projects. Shoring reduces labor costs and increases production times, while bracing holds up a structure before it reaches full strength.
Shoring supports and suspends structures like formwork, underpinning, and face cuts in the earth. Conventional shoring – a 20K all-steel frame that looks like scaffolding –is the most common kind on jobsites, but other options exist.
Aluminum shoring is a high-capacity design that has ledger frames to brace each other. Horizontal adjustable shores set up on an already-existing structure. Shoring tables have wheels that are hydraulically or manually put into position and then rolled to the next location.
Choosing shoring for the job often comes down to three factors: price, production, and load capacity, according to Gary Jividen, regional sales manager, Form Tech Concrete Forms Inc., Poca, W.Va. Although conventional systems are the most common because of lower pricing, they are not always the fastest, which leads some contractors to other options. “When it comes to construction, labor plays the biggest part, and if the contractor can save with shoring, he will choose the equipment accordingly and make money,” said Jividen.
A bracing system – generally diagonal to the principle members – stiffens a structure. Various types of bracing exist. One is a compression style and needs to be placed on both sides of the wall. Another type consists of a steel connector that goes through the wall, allowing the use of a dead man to withstand multidirectional wind loads.
OSHA requires that adequate bracing be present to prevent accidents until a permanent structure is set up, leading to the question of what “adequate” means. Unlike pre-cast and tilt-up walls, which have most of their final design strength when first erected, masonry walls are susceptible to wind damage and start severely altering their shapes in winds in excess of 60 mph.
The Standard Practice for Bracing Masonry Walls under Construction from the Mason Contractors Association of America mandates that wall bracing be designed to resist wind speeds of 40 mph. This figure was determined by a council of contractors, masonry design professionals, and an OSHA representative.
This information and photograph was provided by Universal Mfg. Corp., Zelienople, Pa., a manufacturer of scaffolding, tube and clamp, and shoring.
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