ASDSO Dam Safety Toolbox

Continuous Drive Sampling: Difference between revisions

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"This method consists of forcing a tube into soil materials and withdrawing material retained inside the tube. Tubes are driven by use of a drive hammer or pushed using a jack or hydraulic cylinders against the weight of the rig. Continuous drive test holes can be made in clays, silts, and relatively stable materials free from gravel, cobbles, and boulders. The sampler, when withdrawn, acts as a piston in the hole, causing more excessive caving then other methods of boring."<ref name="NEH_CH5">[[National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing | National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing, NRCS, 2012]]</ref>
"This method consists of forcing a tube into soil materials and withdrawing material retained inside the tube. Tubes are driven by use of a drive hammer or pushed using a jack or hydraulic cylinders against the weight of the rig. Continuous drive test holes can be made in clays, silts, and relatively stable materials free from gravel, cobbles, and boulders. The sampler, when withdrawn, acts as a piston in the hole, causing more excessive caving than other methods of boring."<ref name="NEH_CH5">[[National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing | National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing, NRCS, 2012]]</ref>


"Although highly recommended for logging purposes, continuous drive sampling represents a slow method of advancing holes if logging is not the primary purpose of the boring. Even minor changes in soil materials are visible when the sample is extruded from the tube. However, when used for logging purposes, the hole should be advanced by other means, such as with hollow-stem augers and tubes that will fit through the inner diameter of the hollow stem augers to provide wall clearance. Continuous drive sampling is generally impractical for advancing holes with diameters larger than 3 inches."<ref name="NEH_CH5" />
"Although highly recommended for logging purposes, continuous drive sampling represents a slow method of advancing holes if logging is not the primary purpose of the boring. Even minor changes in soil materials are visible when the sample is extruded from the tube. However, when used for logging purposes, the hole should be advanced by other means, such as with hollow-stem augers and tubes that will fit through the inner diameter of the hollow stem augers to provide wall clearance. Continuous drive sampling is generally impractical for advancing holes with diameters larger than 3 inches."<ref name="NEH_CH5" />


==[[Best Practices Resources]]==  
==<noautolinks>Best Practices Resources</noautolinks>==  
{{Document Icon}} [[National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing | National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing (NRCS, 2012)]]
{{Document Icon}} [[National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing | National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing (NRCS, 2012)]]



Revision as of 04:32, 14 December 2022


Operating a Drill Rig

"This method consists of forcing a tube into soil materials and withdrawing material retained inside the tube. Tubes are driven by use of a drive hammer or pushed using a jack or hydraulic cylinders against the weight of the rig. Continuous drive test holes can be made in clays, silts, and relatively stable materials free from gravel, cobbles, and boulders. The sampler, when withdrawn, acts as a piston in the hole, causing more excessive caving than other methods of boring."[1]

"Although highly recommended for logging purposes, continuous drive sampling represents a slow method of advancing holes if logging is not the primary purpose of the boring. Even minor changes in soil materials are visible when the sample is extruded from the tube. However, when used for logging purposes, the hole should be advanced by other means, such as with hollow-stem augers and tubes that will fit through the inner diameter of the hollow stem augers to provide wall clearance. Continuous drive sampling is generally impractical for advancing holes with diameters larger than 3 inches."[1]

Best Practices Resources

National Engineering Handbook: Chapter 5 - Engineering Geology Logging, Sampling, and Testing (NRCS, 2012)



Citations:



Revision ID: 5573
Revision Date: 12/14/2022