Regional stress field as determined from electromagnetic radiation in a tunnel

摘要: Abstract The paper presents the results of electromagnetic radiation (EMR) measurements in Feuerberg tunnel southwest Germany. EMR is associated with small scale fracturing processes. measured numbers impulses are shown to be proportional shear stresses. From correlation and stresses along long axis tunnel, orientations magnitudes horizontal principal determined. major stress 3.6±0.3 MPa has an azimuth 143±6°. minor 2.1±0.3 MPa. Zones located where low occur because vertical overburden equal. In these zones also minimum was detected. A possible accumulation close a fault suggested by higher values part tunnel. Orientations stresses, which derived from EMR, correlate well conventional measurements. It that cross-section measuring method described study used determine regional fields as investigate endangered high underground facilities, may critical regard stability.