Shallow foundations are widely used in many earthquake-prone regions, where the structures founded upon them are insufficiently valuable for pile foundations to be used. It is widely known that the bearing capacity of a shallow foundation is reduced when the foundation is subjected to rocking moments and horizontal loads during an earthquake event. This paper discusses a series of experiments carried out on a shaking table at Cambridge University in order to measure both the displacements of the foundation due to seismic loading and also the development of the failure mechanism within the soil. The failure mechanism was studied using the technique of Particle Image Velocimetry, (PIV), which has been widely used in the field of fluid mechanics to measure displacements. A series of images was recorded looking at the cross-section of the model using a high frame-rate digital camera. Each image was then split into patches and the best match for each of these patches in the next image of the series was found in order to generate displacement and hence strain fields. The failure mechanisms measured are compared with the theoretical results found from upper and lower bound solutions and the effects of such parameters as earthquake magnitude and frequency are discussed.
|Title of host publication||Proceedings of the 11th International Conference on Soil Dynamics and Earthquake Engineering, Berkeley, California, 7-9 January|
|Place of Publication||United States|
|Number of pages||6|
|Publication status||Published - 2004|