Initiation of pore pressure rise in earthquakes

摘要

Downhole recordings of ground acceleration and pore pressure obtained from several earthquakes are used to investigate the initiation of pore pressure increase. A shear strain threshold mechanism for triggering of pore pressure rise proposed by Dobry, et al. (1982) is considered in detail. Downhole acceleration records are used to synthesize actual shear strain time histories. The times at which the measured strains surpass the proposed strain threshold are contrasted with the times at which pore pressure increase was first measured. Good agreement is found.