Lift-slab construction after the Bridgeport collapse

September 26, 1987

MEMORANDUM FOR: REGIONAL ADMINISTRATORS

THROUGH: LEO CAREY, DIRECTOR
DIRECTORATE OF FIELD PROGRAMS

FROM: THOMAS J. SHEPICH, DIRECTOR
DIRECTORATE OF COMPLIANCE PROGRAMS

SUBJECT: Lift Slab Construction

The attached new release, citations, and report from the National Bureau of Standards concerning the Bridgeport, Connecticut catastrophe is forwarded for your review.

Because of the serious concerns affecting employee safety arising for our preliminary review of the NBS report, we have requested that construction firms not engage in lift slab operation until:

• they are able to assure that each and every component of the lifting system (including, but not limited to, such elements as lifting rods; lifting angles, lifting nuts, and fillet welds) are in conformance with the requirements of ANSI A10.9-1970 and

• A progressive failure analysis is conducted by a qualified engineer to determine what temporary and/or permanent supports (including, but not limited to, such elements as guy wires, shear walls, cribs, and blocks) would be needed during the construction process to assure that a localized failure (e.g., failure of the concrete around the shearhead, failure of any component of the lifting system, a weld failure on the column or on the shearhead supports) would not precipitate a building collapse.

Employers complying with the above mentioned criteria must also adhere to our construction standards for lift slab construction. 29 CFR 1926.700(a), a provision of OSHA's Construction Industry Standards for Concrete, Concrete Forms, and Shoring, stipulated that "all equipment and materials used in concrete construction and masonry work shall meet the applicable requirements for design, construction, inspection, testing, maintenance and operations as set forth in (American National Standards Institution) ANSI A10.9-1970, Safety Requirements for Concrete Construction and Masonry Work."

The ANSI requirement that no one shall be permitted under the slab during the slab jacking operations has been clarified to mean that no employee will be allowed in the building during lifting operations except those employees necessary to secure the slabs to the columns.

All Regional Administrators are requested to notify this office immediately if they are aware of lift slab construction projects which are presently underway or planned for future construction. If you have any questions please contact the Directorate of Compliance Programs, Office of Construction and Maritime Compliance Assistance, FTS 532-8124.

[News release, citations, and National Bureau of Standards report mentioned as attached are not reproduced on OSHA's page.]