Civil Engineering Reference
In-Depth Information
Ownership of the project changed a number of times, with changes in
architects and engineers. This situation added to the overall confusion and
contributed to the irregularities cited above. Some of the key changes are
discussed in King and Delatte (2004).
The general contractor only had a single employee on site, and most
subcontracts were issued directly by the owner to the subcontractors and
bypassed the general contractor. At least seven subcontractors were
involved.
The structural concrete subcontract did not require any inspection or cold
weather protection of the work, although the designer had specified these
measures. There was no evidence of any inspection of the work by an
architect or engineer, although the project specifications required this.
The concrete materials and quality control were poor.
The triggering mechanism of the collapse was punching shear at the roof
slab around column E5, probably preceded by flexural yielding of the roof
slab adjacent to the east face of the elevator core.
The construction did not conform to design documents and the
construction procedures and materials were deficient. The design
documents specified a 28-day strength of 20 MPa (3,000 lb/in.
2
). At the
time of the failure, 47 days after casting, the concrete had yet to achieve
the required 28-day strength. The most significant deficiencies were a lack
of shoring under the roof slab and low-strength concrete.
References
Delatte, Norbert J. (2009).
Beyond Failure: Forensic Case Studies for Civil
Engineers
, ASCE Press, Reston, VA, 133 - 134.
Granger, R. O., Peirce, J. W., Protze, H. G., Tobin, J. J., and Lally, F. J. (1971).
The
Building Collapse at 2000 Commonwealth Avenue, Boston, Massachusetts, on
January 25, 1971
, Report of the Mayor's Investigating Commission, The City
of Boston, MA.
King, S., and Delatte, N. J. (2004). “Collapse of 2000 Commonwealth Avenue:
Punching Shear Case Study,”
Journal of Performance of Constructed
Facilities,
18(1), 54-61.
