Seismic survey

Seismic surveying investigates the subsurface by measuring how fast artificially generated elastic waves travel through the ground. A sledgehammer or dedicated source creates the wave, geophones laid out on the surface pick it up, and a seismograph records arrival times with high precision.

Azerbaijan, and Baku and the Absheron peninsula in particular, lie in a seismically active zone, so the seismic soil category is a key input for earthquake-resistant structural design. From compressional (P) and shear (S) wave velocities we derive the soil category, the average shear-wave velocity in the top 30 m (Vs30), dynamic moduli and Poisson's ratio.

We use seismic refraction, multichannel analysis of surface waves (MASW) and, where required, downhole seismic logging. Profiles are run alongside geotechnical boreholes so that seismic results can be correlated with the drilling data.

Results are delivered in a form designers can use directly: velocity sections, tables and conclusions in line with the applicable seismic codes (AzDTN).

When you need it

• Design of high-rise buildings and critical structures
• Determining seismic soil category and Vs30
• Input data for seismic microzonation
• Locating the top of bedrock and the weathered zone
• Studying stratigraphy where drilling is impractical

What's included

• Seismic profile design
• Field acquisition using refraction and MASW
• P- and S-wave velocity determination
• Calculation of Vs30 and dynamic parameters
• GNSS RTK positioning of profiles
• Correlation with borehole data

How we work

1. Reviewing project data and requirements
2. Laying out profiles and geophone spreads
3. Recording seismic signals
4. Processing and building the velocity model
5. Preparing and handing over the report

Deliverables

• P- and S-wave velocity sections
• Conclusion on seismic soil category and Vs30
• Table of dynamic deformation parameters
• Profile layout plan and technical report