Downhole

Software for processing seismic tests using the DownHole method.

Once entered the information for the project, the depth reached, and the travel times, we can get:

• • the distances from the source to the receiver;
  • corrected travel times;
  • speeds of P and S waves;
  • some important geotechnical parameters;
  • the travel time graph with seismic layers from which can be determined the average velocity in each layer, some average geotechnical parameters and VS30;
  • the graph of P and S waves interval velocity and definition of seismic layer;
  • graphics relating to geotechnical parameters, derived for each interval;
  • the stratigraphy of the borehole;
  • the final report.

The import of SEG2 files ensures this software’s high compatibility with the working tools.

INTERPRETATION WITH DIRECT METHOD

With the direct method, initially, the travel times (t) measured along the source-receiver paths must be corrected to take into account the inclination of the path of the waves and then realize the chart tcor-z, for both P waves and S waves.

Thus, the average speed of seismic waves in homogeneous soil layers is represented by the inclination of the line segments aligned to the experimental data.

Once the seismic layers are graphically obtained, we get the average density, from the speed and depth, Poisson’s ratio, shear deformation modulus, oedometric modulus, Young’s modulus, bulk modulus, VS30.

INTERPRETATION WITH INTERVAL METHOD

In the interval method, travel times are measured between two receivers placed at different depths, thus allowing for better-quality measurements (speed intervals).

When we have only one receiver, assuming that the pairs do not match a single impulse, the rate-determined values are defined in the pseudo-range, allowing only an apparent better definition of the velocity profile.

Once we have the measurements is possible to calculate the corrected travel times and interval velocity for the P and S waves, along with the related graphic.

Then we can calculate the density, Poisson’s ratio, the shear deformation modulus, the oedometric modulus, Young’s modulus, the bulk modulus for each interval and VS30.