BRI Research Paper


Earthquake Response Analysis of Full-Scale Six-Story Concentrically K-Braced Steel Building -Part of the U.S./Japan Cooperative Research Program-.

M.Midorikawa*1, I.Nishiyama*2, H.Yamanouchi*3; October, 1989. 176p.


This paper compares analytical predictions with a series of full-scale seismic tests on a concentrically K-braced six-story steel building. A computer program for the inelastic frame analysis is used to calculate the seismic response of the test building, in which the degrading hysteresis rule is applied to the post-buckling brace model.

As a result of the comparison of the elastic story stiffness between the static frame analysis and the full-scale test, it is emphasized that the three dimensional effects by the transverse cross-bracing, the axial deformation of the floor members and the rigid links assumed at the column ends are remarkably significant to evaluate the elastic story stiffness accurately. From a comparison of the analytical and experimental results, it is concluded that the overall and local behavior of the full-scale test building subjected to simulated earthquakes can be reasonably well represented by using the implemented frame model and analytical method. It should, however, be noted that the overall

hysteresis behavior and the damage distribution of the K-braced building are easily affected by the difference of the hysteresis characteristics of each bracing members assumed in the frame model.

According to the simple analysis with lumped mass shear-type model to compare the earthquake responses between this design level analysis and the full-scale test results, the horizontal floor displacement response of the building does not contradict so much if considered from the viewpoint of the design level analysis. However, it should be noted that the analytical damage concentration along the height of the building obtained from this simple model is considerably different from the experimental one. The seismic performance of the test building is further estimated on the basis of the energy concept. It is pointed out by applying the diagnostic standard based on the energy concept that the test building possesses the sufficient resistability against the severest earthquake. Although the predicted energy absorption capacity of the test building by this diagnostics is a safe-side estimation compared with the experimental result, the prediction of its capacity is appropriate from the standpoint of the earthquake resistant design.

*1 Head, Earthquake Engineering Division II, International Institute of Seismology & Earthquake Engineering.
*2 Senior Research Structural Engineer, Earthquake Engineering Division I, International Institute of Seismology & Earthquake Engineering.
*3 Head, Structural Dynamics Division, Structural Engineering Department.

Note: A part of this paper has already been reported in Refs. 6, 7, 8,9, 10, 13, 20, 21, 22, 27 and 29.

Home | Back

Japanese HP


(c) BRI All Rights Reserved