A proper geotechnical investigation should include boreholes with SPT and detailed laboratory testing. This should be supplemented with CPTu testing. Use an electric cone with pore pressure transducer and (preferably) seismic transducer for performing seismic CPT.

Pressuremeter tests can enhance the quality of the data for foundation analysis. The test should be performed at 3-4 m depth intervals in the boreholes.

For a detailed site characterization, geophysical testing is essential to assess the liquefaction potential, behavior under dynamic loads and to establish the continuity of the strata between the boreholes. This may include cross-hole seismic tests, seismic refraction tests, MASW tests, electrical resistivity imaging, etc.

Thank you, Ravi Sundaram, for your insightful response! I appreciate your recommendation for a comprehensive geotechnical investigation, including boreholes with SPT and detailed laboratory testing. The addition of CPTu testing, especially using an electric cone with pore pressure transducer and seismic transducer for seismic CPT, is a valuable suggestion for enhancing accuracy in complex subsurface environments.

I'm curious if you could elaborate further on the specific advantages or challenges associated with incorporating seismic CPT into geotechnical site characterization. Additionally, are there any particular case studies or projects where you have seen notable improvements in accuracy using these advanced techniques?

Advantage of seismic cone is that it gives you a profile of shear wave velocity with depth along with CPT data. There is significant time and cost-saving in comparison to a cross-hole seismic test.

Challenge: 1. Test cannot be done in rock / refusal strata

2. It has a limited footprint in India.

Dear Mr. Sundaram,

Thank you for your insightful response regarding the advantages and challenges of seismic cone penetration testing. Your expertise is greatly appreciated.