A Benchmark Problem for Collapse Prediction of Steel Structures

Swaminathan Krishnan

Submitted 2010, SCEC Contribution #1395

To aid in the evaluation of the collapse-prediction capability of competing methodologies, a benchmark problem of a water-tank subjected to the Takatori near-source record from the 1995 Kobe earthquake, scaled down by a factor of 0.32, is proposed. The water-tank, supported by a 5-segment steel lattice tower, is so configured as to have a collapse mechanism that is always triggered due to catastrophic column and brace buckling at the bottom-most segment under all forms of ground motion. A FRAME3D model of the tank reveals severe buckling in the bottom mega-columns on the west face of the tower, followed almost instantaneously by compression brace buckling on the north and south faces, when the structure is hit by the Takatori near-source pulse, resulting in a tilt in the structure. Subsequent shaking induces P-Delta instability resulting in complete collapse of the tank.

Krishnan, S. (2010). A Benchmark Problem for Collapse Prediction of Steel Structures. Journal of Structural Engineering, (submitted).