11:45 AM - 12:00 PM
[MIS02-11] Applications of DCDA method for in-situ crustal stress measurement - Rock core samples from NIED seismic observation wells -
Keywords:DCDA method, in-sitsu crustal stress, rock core, seismic observation well
We used recovered hard rock cores from 7 Hi-net obsevation wells of NIED (more than 10 years ago) from the depth about 100m - 200m (one is from the depth of 2000m). The circumferential core diameter variation was measured by an especially designed apparatus that consists of an optical micrometer, a pair of motor-driven rollers and a data processing system (Funato and Ito, 2017, IJRMMS). We got the sine curves of circumferential diameter variation associated with stress relief. However, in some cases, we got the sine curve of circumferential diameter variation obviously related petrogical suructure of sedimetary rocks.The data suggest that the DCDA method is applicable to boring cores from shallow seismic obsevation wells, except for sedimetary rock cores.