The Standard Penetration Test (SPT) is one of the most widely used soil investigation techniques in Bangladesh. However, SPT data are often unreliable due to the use of non-standard equipment and procedures, unskilled rig operators, and the absence of regulatory oversight. In this study, both manually operated rope-cathead and semi-automatic trip SPT rigs were assessed at six different sites, each operated by a separate driller. The qualitative assessment involved a questionnaire survey of rig operators, visual inspection of apparatus, and observations of operational procedures. The quantitative assessment included measurements of hammer mass, hammer free-fall height, and the dimensions of the split-barrel sampler and sampling/drill rods. The qualitative findings indicated that none of the rig operators had received professional training to conduct SPTs, and all lacked awareness of most standard testing procedures. Additionally, several split-barrel samplers were found to be rusty and deformed. Deviations from standard specifications were also identified in hammer mass and in the dimensions of the samplers and sampling/drill rods during the quantitative assessment. The hammer’s free-fall height was recorded during a total of 1629 blows using high-definition video across five manually operated rigs. Of these, only 621 blows corresponded to the standard free-fall height of 762 mm, while the remaining 1008 blows were released from heights either greater or less than the standard. Overall, the study revealed a significant lack of uniformity in both testing apparatus and operational procedures across drillers. The findings are expected to provide valuable insight into the current state of SPT practice in Bangladesh and highlight critical areas for improvement.

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A Qualitative and Quantitative Assessment of Standard Penetration Test (SPT) Practices in Bangladesh

  • Mohammad Mominul Hoque,
  • Reshma,
  • Md. Hasibul Islam

摘要

The Standard Penetration Test (SPT) is one of the most widely used soil investigation techniques in Bangladesh. However, SPT data are often unreliable due to the use of non-standard equipment and procedures, unskilled rig operators, and the absence of regulatory oversight. In this study, both manually operated rope-cathead and semi-automatic trip SPT rigs were assessed at six different sites, each operated by a separate driller. The qualitative assessment involved a questionnaire survey of rig operators, visual inspection of apparatus, and observations of operational procedures. The quantitative assessment included measurements of hammer mass, hammer free-fall height, and the dimensions of the split-barrel sampler and sampling/drill rods. The qualitative findings indicated that none of the rig operators had received professional training to conduct SPTs, and all lacked awareness of most standard testing procedures. Additionally, several split-barrel samplers were found to be rusty and deformed. Deviations from standard specifications were also identified in hammer mass and in the dimensions of the samplers and sampling/drill rods during the quantitative assessment. The hammer’s free-fall height was recorded during a total of 1629 blows using high-definition video across five manually operated rigs. Of these, only 621 blows corresponded to the standard free-fall height of 762 mm, while the remaining 1008 blows were released from heights either greater or less than the standard. Overall, the study revealed a significant lack of uniformity in both testing apparatus and operational procedures across drillers. The findings are expected to provide valuable insight into the current state of SPT practice in Bangladesh and highlight critical areas for improvement.