Subpart Q
A registered professional engineer experienced in lift-slab construction must design and plan lift-slab operations, and the employer must implement those plans which include detailed instructions, sketches, and provisions for lateral stability. See the Requirement in 1926.705(a).
Jacks and lifting units must be marked with their manufacturer-rated capacity and must not be loaded beyond that rated capacity. See the marking requirement in 1926.705(b) and the loading limit in 1926.705(c).
Jacking equipment must be capable of supporting at least two and one-half times the load being lifted during jacking operations and must not be overloaded. See the strength requirement in 1926.705(d).
Threaded rods, lifting attachments, lifting nuts, hook-up collars, T-caps, shearheads, columns, footings, and other load-bearing components are jacking equipment, and jacks/lifting units must be designed/installed so they will neither lift nor continue to lift when loaded in excess of their rated capacity. See the equipment definition and the design requirement in 1926.705(e).
Jacks and lifting units must have a safety device that will cause them to support the load in any position if a jack malfunctions or loses lifting ability. See the safety-device requirement in 1926.705(f).
Jacking operations must be synchronized to ensure even and uniform lifting so that all supporting points are kept within 1/2 inch of level to maintain the slab in a level position. See the synchronization and tolerance rule in 1926.705(g).
If leveling is automatically controlled, a device must be installed that stops the operation when the 1/2 inch tolerance in 1926.705(g) is exceeded or when there is a malfunction in the jacking system. See 1926.705(h).
If leveling is maintained manually, the manual controls must be located in a central location and attended by a competent person experienced in the lifting operation and equipment while lifting is in progress. See 1926.705(i) and the competent person requirement at 1926.32(f).
The competent person must meet the definition in 1926.32(f) and must also be experienced in the lifting operation and with the lifting equipment being used. See the competence requirement described with 1926.705(j).
No more than 14 manually controlled jacks/lifting units are allowed on one slab; the actual maximum may be lower to permit the operator to maintain level within the 1/2 inch tolerance. See the numeric limit in 1926.705(j).
Only employees essential to the jacking operation may be in the building while jacking is taking place unless a separate independent registered professional engineer has determined the structure is reinforced sufficiently to ensure integrity; under no circumstances may nonessential employees be permitted immediately beneath a slab while it is being lifted. See 1926.705(k)(1) and 1926.705(k)(2).
A jacking operation begins when a slab or group of slabs is lifted and ends when those slabs are secured with either temporary or permanent connections. See the definition of a jacking operation in 1926.705(k)(3).
An employer who complies with Appendix A to 1926.705 will be considered in compliance with paragraphs (k)(1) through (k)(3). See the compliance option in 1926.705(k)(4).
Wedges used for temporary connections must be secured by tack welding or an equivalent method to prevent them from falling out, and lifting rods must not be released until the wedges at that column have been secured. See the wedge and lifting-rod rule in 1926.705(l).
All welding on temporary and permanent connections must be performed by a certified welder who is familiar with the welding requirements in the lift-slab plans and specifications. See 1926.705(m).
Load transfer from jacks/lifting units to building columns must not be executed until the welds on the column shear plates (weld blocks) have cooled to air temperature. See the cooling requirement in 1926.705(n).
Jacks and lifting units must be positively secured to building columns so that they do not become dislodged or dislocated. See the securing requirement in 1926.705(o).
Leveling tolerances may be controlled either automatically (with a device that stops operations if the 1/2 inch tolerance is exceeded or on malfunction) or manually (with controls in a central location attended by a competent person); if manual, a competent, experienced person must be present and actively maintain level within the 1926.705(g) 1/2 inch tolerance. See 1926.705(h) and 1926.705(i).