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Sampling Frozen Soils

John Poullain, P.E.


Course Outline

This three hour online course discusses drilling equipment and procedures used for soil sampling in frozen soils, and methods for recovering the soil samples. Visual examination and other measures used during drilling and sample recovery are considered. The types of equipment and drilling methods covered in the course include solid-stem, hollow-stem augers, bucket augers, and Rand auger boring. Guidelines for a variety of samplers including split barrel, thin wall tubes, block, pitcher and continuous soil auger are discussed as well as the handling, selection and storage of specimen samples. Basic soil types and how drilling and sampling in frozen states differ from unfrozen conditions and are considered in the selection of appropriate drilling and sampling methods. Also covered is artificial ground freezing methods for dealing with groundwater problems.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will have reviewed the following topics:


Intended Audience

This course is a general guide intended for civil engineers, and project engineers.


Benefit to Attendees

The student will become familiar with the guidelines and criteria for sampling frozen soils


Course Introduction

The design of building foundations, roadways, excavation, fills and slopes requires an understanding of soil strength; soil characteristics and consideration of problem soils and how soil behaves under imposed loads. Drilling and core samples provide the necessary samples for laboratory tests and for in-situ field-testing. It is important to follow the criteria and guidelines so the appropriate drilling methods are selected especially since subsurface exploration is expensive but not as expensive as a project failure.

Because of the large variety of soils and a large variety of applied soil mechanics problems there is also a large variety of soil exploration and sampling methods for determining the engineering properties of soils. Before the boring program can be requested the design engineer must define the purpose for the exploration program and the testing program for his self and for field and laboratory personnel. Accurate observations and operations of the exploration equipment are of great importance and the equipment must be properly maintained, otherwise the sampling results will be valueless and result in poor design and construction.

Not only must exploratory personnel be well trained and conscientious; the drilling and sampling equipment must also provide accurate samples and data for a variety of tests. Samples must be handled and stored with care following established standards. Samples should be inventoried, examined and tested as soon as they are received. Sometimes, especially for large testing programs, it may become necessary to store the samples for days or weeks, but no longer than 15 days If possible. If they are stored for a longer time the undisturbed samples should be protected against damage or changes in water content by maintaining at temperatures close to those required for the project or for frozen soils the in situ temperature. Rewaxing and relabeling may be required. Nevertheless the stored samples may undergo physical and chemical changes when stored too long no matter how carefully stored and resealed.

Artificial ground freezing has been used for several decades for in drilling and sampling difficult soil formations. It has been used more extensively for groundwater control and excavation in underground construction projects since it is very effective in controlling the groundwater and to provide soil support for shaft construction in water-bearing formations. By artificially freezing the pore water of soils a stronger more stable material is created and ground water problems are solved.

Artificial ground freezing has more recently been used for environmental remediation projects by creating subsurface barriers. Frozen earth barriers prevent contaminated groundwater from migrating while remediation is being performed. Installation of the barriers may be for temporary use or for long term use.

Course Content

The course is primarily based on Chapters F-2, F-5 and F-9 of the US Army Corps of Engineers manual EM 1110-1-1804, “Geotechnical Investigations”, (2001 Edition, 31 pages), PDF file. The course is also base on pages 16-22 of the US Army Corps of Engineers Special Report 86-27, “Drill Bits for Frozen Fine-Grained Soils”, (1986 Edition, 8 pages), PDF file.

The links to the those documents are:

Chapters F-2 of the US Army Corps of Engineers manual EM 1110-1-1804, “Geotechnical Investigations”

Chapters F-5 of the US Army Corps of Engineers manual EM 1110-1-1804, “Geotechnical Investigations”

Chapters F-9 of the US Army Corps of Engineers manual EM 1110-1-1804, “Geotechnical Investigations”

US Army Corps of Engineers Special Report 86-27, “Drill Bits for Frozen Fine-Grained Soils”, (1986 Edition, 8 pages)

Terms

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

This course should serve as a guide for selecting the proper equipment for drilling and sampling in frozen soils. The advantages and limitation of soil drilling equipment, drilling fluids and samplers are discussed along with photographs to better understand the equipment. Basic soil types are discussed to understand the selection of soil drilling methods. The importance of following proper sampling procedures is stressed and the proper storage, handling and selection of soil specimens for testing programs are considered. Artificial ground freezing methods for groundwater problems, boring certain soils and for underground excavations are presented.


Related Links

For additional technical information related to this subject, please refer to:

http://www.haywardbaker.com/
Information describing construction methods for structural support and earth retention are given. Solution “tools” for problem soils and applications for projects are available.

http://www.usace.army.mil/publications/eng-manuals/em1110-2-1913/c-3.pdf
Describes lab tests for pervious and fine-grained cohesive soils and the soils characteristics tested for.

http://www.ggsd.com
Lists over 50 software packages, shareware or commercial as noted, for soil boring logs and subsurface profiling.

http://www.laynechristensen.com/test/GroundF
Artificial ground freezing for environmental remediation barriers, subsurface soil properties and installation procedures are discussed.

 

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.