Sharma A.,HS and EG |
Mahrenholtz C.,University of Stuttgart |
Eligehausen R.,University of Stuttgart |
Reddy G.R.,HS and EG |
And 3 more authors.
International Journal of Earth Sciences and Engineering | Year: 2010
In the event of an earthquake, the anchor in a crack experiences cyclic tension loads, cyclic shear loads and cyclic opening and closing of cracks (crack cycling). As a conservative assumption, it is assumed that the anchor is subjected to the peak load when the crack is open to its maximum possible crack width value. The assumption, though safe is unrealistic and highly conservative, because for such a case, the frequency of load and crack cycling should be equal and also should be in phase with no lag. However, due to difference in mechanisms for transfer of load on anchor and crack opening loads, the frequency of load cycling and frequency of crack width (CW) cycling will, in general be different. Moreover, due to reasons such as the cohesion at the tips of the crack, the crack width cycling in general always lags behind the load cycling. Therefore, in general when the crack width is at maximum the possibility that the load will also be at peak is quite low. In this report, a simple and effective probabilistic approach is used to realistically evaluate the probability that when the crack width is opened to a maximum, the load on anchor is less than or equal to certain percentage of peak load. Three cases are considered namely any given possibility of frequency ratio and phase as equally likely, which is quite conservative, a more realistic normal distribution function for frequency and another even more realistic Fisk distribution. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.