Application of seismic instrument placement location selection based on comprehensive deep well in Shanghai Changjiang Farm Station of PS wave velocity test
Zhifeng Liu · Progress in geophysics · 2015
Comprehensive deep Shanghai Changjiang Farm Station was built in 2011,installed magnetometer,strain gauge, inclinometer, seismometers, pore pressure,temperature, water temperature instrument, water meter installation site in deep well,.Through the formation of PS wave velocity test can know the structure of the area's formation and the project site seismic effect.This is finished in the quaternary loose soil drilling,casing,before the puckering method of PS wave velocity test,valuable information and good results have been achieved.In Shanghai comprehensive deep project,the American production of S-Land digital seismic instrument and VCANTS5 control controller device,the Changjiang Farm Station successfully to the well depth of 400 meters of deep PS wave test,has obtained the precious soil data.Based on the analysis of the Changjiang Farm Station in Shanghai test results, we can scientific and reasonable to determine the instrument placement,ensure the equipment running well.Changjiang Farm Station PS wave test results and analysis results as follows:in the installation of down hole seismometer is 400 meters,S wave formation is larger than 600m/s,showed that the soil properties are good.At a depth of290 meters,dynamic Poisson's ratio decreased,numerical near0.42,show that this formation has become more dense in the gravity under the action of seismic instruments,pre layer can be placed at the same time.In view of the influence by the environment noise of the instrument,the soil structure was better,selected the deepest place seismic instrument,can obtain high quality monitoring data.Select the appropriate instrument placement,monitoring data can obtain high quality,for every million comprehensive deep bench is essential,to ensure the efficient operation of station equipment.The test data of PS wave of the Changjiang farm this acquisition provides valuable experience for the future to build more comprehensive deep well.