The Earthquake Engineering Online Archive

Capacity of columns with splice imperfections

Popov, Egor P.; Stephen, Roy M.; Philbrick, Robert A.

UCB/EERC-76/21, Earthquake Engineering Research Center, University of California, Berkeley, 1976-09-01, 61 pages (515/P651/1976)

The milled or cut surfaces at column splices as a general rule do not make a perfect full and even contact. Recognizing this fact, the AISC Code of Standard Practice accepts a maximum gap of 1/16 in. at the faying surfaces. Data on the behavior of such imperfectly spliced columns are very limited. Therefore, in this investigation the behavior of two W 14x176 columns with the currently allowed 1/16 in. gaps at the splices and two similar columns with 1/4 in. gaps and shims inserted in accordance with the AISC Quality Criteria and Inspection Standards were compared with the behavior of an unspliced column of the same size. Four of the columns were 14 ft 8 in. long; one was 10 ft long. The results showed that the lack of perfect contact at the compression splices of these stubby columns is not serious, provided that the gaps are carefully shimmed and welding is used to maintain sections in alignment. In these tests minimum partial penetration welds only along the flanges were used. The KL/r ratio for the columns tested was approximately 30. Therefore, considerable caution must be exercised in extending the results to the columns having high slenderness ratios. After completion of the compression tests the specimens were tested in tension. Since only minimum partial penetration welds along the flanges were provided at the splices, all failures occurred through the welds. Some observed lack of uniformity of the weld size suggests the need for a visual inspection of such welds if the members are designed to transmit tensile forces. Tensile tests of these full-size specimens provide data on the behavior of such members for aseismic design. Complete load-deflection diagrams are included in the report. No such data appear to be readily available elsewhere.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-76-21.pdf (5 MB)