In-situ Stress Measurement and Analysis in the South Himalayas

摘要

The 3D in-situ stress measurement was conducted at Gongga valley in the south Himalayas for thernfirst time. The maximum principal stress is around 17.0 MPa and its’ direction is approximately N-S.rnThe plunge angle is almost horizontal. The intermediate principal stress is around 13.4 MPa with arnnearly E-W direction. The maximum principal stress is around 8.1 MPa and its plunge direction pointsrndown. Based on the measured data, the characteristic parameters of the main stress tensor wererndetermined. The results indicated that the co-action of the stress pushing and cutting in crustal rock isrnmain characteristic of the local stress state. Then , the high shear stress is the main reason of causingrnfrequent crustal activities in this field.