Seismic stability of block structures
Abstract
When studying earthquake damage reinforced concrete or concrete masonry structures, it was observed that the mechanisms of failure are often simple ones; the vulnerable connections between structural components degrade under stress allowing the major substructures to separate, lose support, and topple. This type of failure is said to result from kinetic instability. For the purpose of analysis, structures with degraded connections are modeled as assemblages of rigid substructures with only friction acting between them. A statistical analysis of data from experiments on concrete masonry members gives an asymptotic Coulomb law describing this friction which is included in the model equations of motion. The equations of motion for a simple shear wall floor slab assemblage subjected to simulated earthquake loading are solved numerically. The result shows a surprisingly well defined relation between the maximum amplitude of excitation, the natural frequency of the structure, and a numerically valued hazard from kinetic instability. When presented graphically, the result allows a designer to assess hazard from kinetic structural instability by inspection.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- March 1980
- Bibcode:
- 1980PhDT........40F
- Keywords:
-
- Concrete Structures;
- Earthquake Damage;
- Failure Modes;
- Seismology;
- Equations Of Motion;
- Structural Stability;
- Engineering (General)