Review the situation and determining the position of fractures and zones of crushed rock tunnels and galleries inject water into the dam and powerhouse Seymareh Tomography

In this paper, we used intra-borehole seismic assays with shear and compressional waves, in order to complete geotechnical view obtained from excavations and dynamically evaluation of project area’s soillayers by seismological engineering approach.Tomography study in supply water and grouting tunnelbeen done to identify crushed zone and cavity. For example in this study a 12- hydrophone streamer with spacing 2 m has been driven from 40 to 62 m in one borehole and sparker has been driven in another borehole at 44 m. (sparker must be located minimum3 m under water level). With start of sparker, streamer receives the seismic wave and recorded by seismograph. This step repeated by stacking to reduce noise level and increase seismic signal.Then sparker has been located at depths 46, 48, 50, 52, 54, 56, 58 and 60 and each depth recorded in separated file. On the next step receivers have been located from 50 to 72 m and sparker located at 60, 62, 64, 66, 68 and 70. This trend is continuing to whole of depth thataccessible swept. Data that has been recorded by seismograph has been saved digitally on diskette. The record length is 24 ms and sample rate is .024 ms in borehole tomography. Thisdata is proceed and for each seismograph first break extracted .the input data (includedlocation of seismic, source and first break) for each section is made. This file run in Geotmo software and by SIRT for each cell obtained velocity. In the end isovelosity section is prepared.

کلیدواژه ها:

Tomography ، tunnel ، sparker ، Geotmo ، seismograph