TECHNIQUE OF STRAIN OBSERVATION IN SOIL WITH SELF-CHECKING FUNCTION
Qiu Zehua 1) ; Tang Lei 1) ; Lu Falin 2) ; and Zhang Baohong 1)
1)Institute of Crustal Dynamics, China Earthquake Administration, Beijing 100085;2)Wenan Seismostation of Earthquake Administration of Hebei Peovinve, Wenan 065800
Abstract A test of continuously observing strain changes in soil has been recording data for over three years in Wenan, Hebei province. A YRY4 type borehole strainmeter of high resolution is used for the horizontal strain observation. The selfchecking function of the YRY4 strainmeter which has four gages ensuring the reliability of the data. Relative insitu calibration is applied to evaluate the operation of the instrument, as well as correct the readings, which is very significant for precisely calculating the principal orientation of changes. Thus data credibility of four gages borehole strainmeter is defined here. A correction using the result of relative insitu calibration entails high data credibility of the YRY4 strainmeter at Wenan, indicates that it has been working well.
