ABSTRACT
The Standard Penetration Test (SPT) is a widely used subsurface exploration technique for site characterization in Bangladesh. However, non-standard practices often result in unreliable SPT N-values. This study examined four manual and four automatic trip SPT rigs across eight different sites. Only one hammer was found to weigh the standard 63.5 kg. A total of 1234 hammer free-fall heights were recorded for manual rigs, of which only 37.5% were re-leased from the standard height of 762 mm. The remaining 62.5% ranged between 610 mm and 940 mm. Although the automatic rigs generally maintained the standard drop height, apparatus and operational errors were still observed. The investigation also found that the physical condi-tion and dimensions of the split-barrel samplers deviated from standard specifications. Non-standard practices were more prevalent in manual rigs. Moreover, none of the rigs fully com-plied with ASTM standards except one, underscoring the need for more rigorous quality control.
