• The Journal of Engineering Geology
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• v.31 no.4
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• pp.541-547
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• 2021

To assess the stability of a slope and the likelihood of its loss or collapse requires information about the ground, such as the composition of the stratum and its mechanical characteristics. This information is generally gathered through standard penetration testing (SPT) and cone penetration testing. SPT is not widely used due to problems with accessing slopes, most of which are steep and without ramps. A drop cone penetrometer, a portable device that can make up for these shortcomings, can be used in a limited way in some circumstances. Therefore, we developed a portable drilling machine and a small dynamic cone penetration test module that can easily access a slope site and perform SPT. The correlation of the developed system's results with those from SPT was analyzed. Analysis of the correlation between the energy shear rate passing to the load during the different test types established that the energy shear rate is reflected in the test result. The correlation between corrected dynamic cone penetration testing and corrected SPT was N_d' = 3.13 N'.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.175-182
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• 2001

The PMT test results are compared with other in situ test such as Standard Penetration Test (SPT), Cone Penetration Test (CPT), Field Vane Test (FVT) and the laboratory test in order to investigate the correlationships for the strength parameters obtained from Busan and Incheon areas. Many proposed correlation formulas also make a comparative study and new correlation formulas for domestic soils are introduced. Limit pressure ( $P_1$) could be determined by P-log($\Delta$V/V) and Relative volume Method. PMT for the granular soils showed relatively high correlation with SPT, while CPT has good correlation with PMT for cohesive soil. The predicted undrained shear test ( $S_{u}$) by the PMT test results for Incheon and Busan samples showed low correlativity with proposed equations, therefore, new correlation formulas are proposed for domestic soils.s.

• Journal of Ocean Engineering and Technology
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• v.26 no.6
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• pp.33-38
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• 2012

In our study, a closed-type penetration unit for standard penetration test (SPT) equipment was developed in order to operate in an underwater environment. This type causes energy dissipation, mainly due to the small gap between an airtight case and moving hammer. The dissipation was estimated through a CFD analysis. The computed dissipated energy was less than 1.2% compared to the potential energy of the hammer with the given gap. Subsequently, the impact energy of the underwater SPT equipment was within 1.2% of that for the SPT equipment on land.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.105-111
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• 2013

The standard penetration test (SPT) has been widely used because of its usability, economy, and many correlations with soil properties among other factors. In SPT, hammer energy is an important factor to evaluate and calibrate N values. To measure hammer energy, an instrumented SPT rod was developed considering that stress waves transferring on rods during SPT driving are the same as stress waves transferring on piles due to pile driving. Using this idea, an instrumented SPT rod with a pile driving analyzer was applied as a pile capacity prediction tool in this study. In order to evaluate this method, SPT and dynamic cone tests with the instrumented SPT rod were conducted and also 2 pile load tests were performed on pre-bored steel pipe piles at the same test site. End bearings were predicted by CAPWAP analysis on force and velocity waves from dynamic cone penetration tests and SPT. Comparing these predicted end bearings with static pile load tests, a new prediction method of the end bearing capacity using the instrumented SPT rod was proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.469-476
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• 2001

The Ν-value in the standard penetration test(SPT) is affected by the magnitude of the rod penetration energy transmitted from the falling hammer as well as the geotechnical characteristics of the ground. Understanding of the striking energy efficiency in the SPT equipment is getting important for that reason. The energy efficiencies of the doughnut hammer with the hydraulic lift system and the automatic trip hammer system were investigated through field tests using the instrumented rod and wave-signal acquisition systems including the pile driving analyzer(PDA) . The rod energy ratio, ΕR$\_$r/ was defined as the ratio of the energy delivered to the drilling rod to the potential free-fall energy of the hammer. It appears that the type of the hammer and lift/drop system had a strong influence on the energy transfer mechanism and ΕR$\_$r/ also varies according to the energy instrumentation system and the analysis methods.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.71-78
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• 2002

The N-value from the standard penetration test(SPT) is affected by the magnitude of the rod penetration energy transmitted from the falling hammer as well as the geotechnical characteristics of the ground. Understanding of the striking energy efficiency in the SPT equipment is getting important for that reason. The energy efficiencies of the various type of equipment were investigated through field tests using the instrumented rod and wave-signal acquisition systems including the pile driving analyzer(PDA). The rod energy ratio, ERr was defined as the ratio of the energy delivered to the drilling rod to the potential free-fall energy of the hammer. It appears that the type of the hammer and lift/drop system had a strong influence on the energy transfer mechanism and ERr also varies according to the energy instrumentation system and the analysis methods.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.477-484
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• 2001

In this paper shows the evaluation of the liquefaction potential of soils using in situ test. There are different types of in situ test used in the evaluation the liquefaction potential. In the particular study the Standard penetration test(SPT), Cone penetration test(CPT), ad Seismic cone penetration test (SCPT) were used. The SPT N value has been used all over for a very long time. The evaluation of the liquefaction of soil was preformed using the worldwide renowned CPT and SCPT. Shake 91 program was used to evaluate the results obtained by different in situ test and were later analyzed.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1425-1434
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• 2009

This study was aimed at comparing and assessing SPT-N values both measured by automatic and manual record devices of Standard Penetration Test. As a result, energy efficiency of hammer was approximately 62.9%, meaning SPT-N value measured by automatic recording device showed relatively accurate performance that the one done by manual device. Given the relations between hit frequency of automatic recording device and intrusion, the characteristics of stratum are expected to be proved in more accurate way. Additionally, higher confidence level seems to make it preferred and quality assessment method.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1359-1364
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• 2008

It is well known that the standard penetration test (SPT) has been used in all over the world to get geotechnical properties of the ground. However, it is difficult to apply the SPT to the dense sand, gravel, weathered rock, etc. For the application of the SPT in these grounds, it is necessary to change in the diameter and the impact energy of the SPT. For the improvement of site investigation technology, Large Penetration Testing device (KICT-type LPT) was developed and applied to the in situ condition. The drop height and weight of the hammer in developed system were decided as 760mm and 150kg, respectively. And the developed sampler has the inner diameter of 63 mm and the length of 500 mm with the adjustment of energy ratio to the SPT of 1.5. In this study, the performance of KICT-type LPT was evaluated by using a calibration chamber system and pile driving analyzer (PDA)

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1340-1352
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• 2008

In this study, S-wave velocity range is gauged in every field test method at the total 5 locations in the marine deposits in Incheon area. field test method is accomplished the SPT(Standard Penetration Test), CPT(Cone Penetration Test), SPS(Suspension PS Logger), SCPT (Seismic Cone Penetration Test) and so on. The S-wave velocity of SCPT in the downhole test method is measured lower than SPS logger at the N value > 15 range. But at the N value < 15 range, SPS logger and SCPT result is measured same. In this result, although the soil strength of the downhole test method increased, the rate of S-wave velocity is tend to be slowed. This result shows that the downhole test is difficult to apply at the place that the intensity of soil is more extreme and harder soil. And it shows that the existing Imai(1982) type that is mostly used within the country is not suitable for the marine deposits. Thus, the empirical formula that can show the range of S-wave velocity in each N value for domestic soil is needed.