Model:SPT
Use:Meets ISO 22476-3:2005, ASTM D1586, D4633, D6066. The SPT Analyzer Determines the Energy Transferred by SPT Hammers using Force and Velocity Measurements, for Improved Reliability of SPT N-values consult
Standard:ISO 22476-3:2005, ASTM D1586, D4633, D6066
What is SPT?
The Standard Penetration Test (SPT) is a widely employed soilexploration tool that involves using a SPT hammer to drive asplit barrel sampler at the bottom of a drill string to obtain soil samples. The number of blows required to penetrate the last
300mm (1ft) is the “N value”, which is related to soil strength.
Several different types of SPT hammers are used to conductStandard Penetration Tests. Their varying efficiencies influencethe N value. The measured N value is normalized by multiplyingit by the ratio of the measured energy transferred to the rodto 60% of the theoretical potential energy. The normalizationcompensates for the variability of the efficiencies of differentSPT hammer types, and improves the reliability of soil strength estimates used in geotechnical applications.
The SPT Analyzer is furnished with a 0.6 m sub assembly (orsection) of an SPT rod (AW, NW or other type) instrumented with
2 strain gage bridges, and precisely calibrated by Pile Dynamics.Once in the field, two accelerometers are bolted to the rodsection. The instrumented section is inserted at the top of thedrill string between the hammer and the existing sampling rod.The rod is connected to the SPT Analyzer.Smart Sensor technology allows the SPT Analyzer to read therod instrumentation, obtaining the sensor calibration and rodcross sectional area. These quantities are input to the SPTAnalyzer automatically without the operator having to enterthem. This significantly simplifies the initial test setup.The strain gages and accelerometers obtain the force and velocitysignals necessary for the calculation of transferred energy as theSPT hammers drive the instrumented rod into the ground. Theenergy is displayed in real time on the SPT Analyzer screen.The latest model of SPT Analyzer responds to multi touch gesturesand have numerous color schemes available, making things likeadjusting time scale or display to better view data in the fieldmuch simpler than previously. A pre-programmed set of outputquantities tailored to SPT calibration is presented to the user,who can, however, modify it to fit a particular project need. Data
quality checks are available.
The SPT Analyzer is compliant withEN ISO 22476-3:2005.ASTM D1586recommends normalizing results from any SPT test using energy measurements. When these tests are performed to determine the liquefaction potential of sands,D6066not only recommends but mandates the normalization.ASTM D4633states that the only acceptable method of determining energy for normalization of N values is by force and velocity measurements.
Technical Specification
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