Soil investigation using multichannel analysis of surface wave (MASW) and borehole

Multichannel Analysis Surface Wave (MASW) measurement is one of geophysics exploration techniques to determine the soil profile based on velocity. Meanwhile borehole intrusive technique identifies the changes of soil layer based on SPT N value. Both techniques were applied at the University campus test site and Parit Jelutong as part of soil investigation. A 7 kg of sledge hammer was used as source, 24 units of 4.5 Hz geophones used as detectors (receivers) and Terraloc Mark 8 ABEM was used as a recorder. SeisImager software was used for seismic data processing. The MASW test configuration was 5 m geophones spacing and 5 m source offset distance at Parit Jelutong, and used 1 m geophones spacing and 2 m offset distance at the University campus test site. All the MASW test array was conducted near to the boreholes. The reliable seismic results at Parit Jelutong were from depth 0.5 m to 14 m and 3.7 m to 27 m the University campus test site, respectively. Comparison between MASW and borehole data indicates that a very soft clay shear wave velocity is below than 165 m/s, soft clay at 170 m/s to 195 m/s and firm layer at 194 m/s to 317 m/s. There was not available shear wave velocity result of hard material. In conclusion, the MASW technique is potential to adapt in soil investigation to compliment the intrusive technique, which is non-destructive, non-invasive nature and relative speed of assessment