CKI-11: Design Guidelines for Ductility and Drift Limits
This report summarizes each of the studies that have been conducted in California as a part of the CUREe-Kajima Research Project #5, entitled "Design Guidelines for Ductility and Drift Limits.'' This research project has been supported by a grant provided by the Kajima Corporation and administered by CUREe (California Universities for Research in Earthquake Engineering). This financial support is gratefully acknowledged.
This report includes the following:
Earthquake Response and Analytical Modelling of the Japanese S-K Building
Chukwuma G. Ekwueme
Gary C. Hart
Thomas A. Sabol
Description of building.
Description of earthquakes.
Response of the building.
- Chiba To-Ho Earthquake.
- Tokyo To-Bu Earthquake.
- Description of the model.
- Mode shapes.
- Time history Analyses and Response Spectra.
Inelastic Analysis of S-K Building
Displacement Design Approach for Reinforced Concrete Structures Subjected to Earthquakes
Jack P. Moehle
An analytical study of the characteristics of inelastic displacement response of single degree-of-freedom (SDOF) systems subjected to earthquake ground motions was conducted to develop practical means of estimating the peak values of the displacement. It is observed that the displacement response can be characterized in two period ranges, divided by the characteristic period of the ground motion. Methods are established by which elastic analysis can be used to estimate the peak displacement response in both period ranges. Therefore, a design displacement response spectrum can be constructed for a given earthquake. The spectrum provides a measure of the expected inelastic displacement using a linear model.
The method of estimating the displacement of inelastic SDOF systems is extended to estimate the peak lateral displacement of multi-story frame structures. The maximum inter-story drift that a frame could experience during a given earthquake is approximated based on the estimated roof level displacement.
A study of the deformation capacities of reinforced concrete frame members and subassemblages is conducted to relate the details provided in reinforced concrete beams and columns to the maximum inter-story drift capacity. It is concluded that the required details for reinforced concrete members can be assessed based primarily on displacement considerations.
A new displacement-based seismic design approach is outlined. Design examples demonstrate that the displacement response of structures can be effectively controlled using this approach. It is concluded that more efficient control of the seismic performance of buildings can be achieved using the displacement design approach. The importance of structural stiffness in resisting earthquake excitations is highlighted in the application of the displacement approach.
Also listed as Report No.: CK92-03D (February 1992)