Geophysical - Revision history

Mpollei@gfnet.com at 22:49, 10 July 2023

2023-07-10T22:49:17Z

← Older revision		Revision as of 22:49, 10 July 2023
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	==<noautolinks>Best Practices Resources</noautolinks>==		==<noautolinks>Best Practices Resources</noautolinks>==
	{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations, NRCS~~, 2012~~]]		{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations, NRCS]]
	{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802), USACE~~, 1995~~]]		{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802), USACE]]
	{{Document Icon}} [[Design of Small Dams \| Design of Small Dams, USBR~~, 1987~~]]		{{Document Icon}} [[Design of Small Dams \| Design of Small Dams, USBR]]

	<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->		<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->

Rmanwaring at 23:15, 19 December 2022

2022-12-19T23:15:08Z

← Older revision		Revision as of 23:15, 19 December 2022
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	"Geophysical methods of subsurface exploration are an indirect means of gathering data pertaining to underground conditions. Using geophysical techniques involves taking measurements at the earth's surface or in boreholes to determine subsurface conditions. Geophysical methods may be employed during any stage of an investigation and include:		"Geophysical methods of subsurface exploration are an indirect means of gathering data pertaining to underground conditions. Using geophysical techniques involves taking measurements at the earth's surface or in boreholes to determine subsurface conditions. Geophysical methods may be employed during any stage of an investigation and include:

	*[[Seismic]],		*"[[Seismic]],
	*Electrical,		*"Electrical,
	*Magnetic, and		*"Magnetic, and
	*Gravity."<ref name="EarthManualP1">[[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]</ref>		*"Gravity."<ref name="EarthManualP1">[[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]</ref>

	"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />		"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />
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	==<noautolinks>Best Practices Resources</noautolinks>==		==<noautolinks>Best Practices Resources</noautolinks>==
	~~{{Document Icon}} [[Design of Small Dams \| Design of Small Dams (USBR, 1987)]]~~		{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations, NRCS, 2012]]
	{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations (NRCS, 2012)]]		{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802), USACE, 1995]]
	{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) (USACE, 1995)]]		{{Document Icon}} [[Design of Small Dams \| Design of Small Dams, USBR, 1987]]

	<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->		<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->

Grichards at 04:44, 14 December 2022

2022-12-14T04:44:10Z

← Older revision		Revision as of 04:44, 14 December 2022
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	[[Category:Geotechnical Exploration]]		[[Category:Geotechnical Exploration]]
	----		----
	~~{{Picture~~
	~~<!-- Add image file name (ex.image.jpg) -->~~
	~~\|image= RemoteSensing.jpg~~
	~~<!--Add link if applicable -->~~
	~~\|link=~~
	~~<!-- Add picture caption -->~~
	~~\|caption= Aircraft Used for Remote Sensing~~
	}}

	<!-- Introductory paragraph or topic page summary -->		<!-- Introductory paragraph or topic page summary -->

	"Geophysical methods of subsurface exploration are an indirect means of gathering data pertaining to underground conditions. Using geophysical techniques involves taking measurements at the earth's surface or in boreholes to determine subsurface conditions. Geophysical methods may be employed during any stage of an investigation and include:		"Geophysical methods of subsurface exploration are an indirect means of gathering data pertaining to underground conditions. Using geophysical techniques involves taking measurements at the earth's surface or in boreholes to determine subsurface conditions. Geophysical methods may be employed during any stage of an investigation and include:

	*[[~~seismic~~]],		*[[Seismic]],
	*~~electrical~~,		*Electrical,
	*~~magnetic~~, and		*Magnetic, and
	*~~gravity~~."<ref name="EarthManualP1">[[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]</ref>		*Gravity."<ref name="EarthManualP1">[[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]</ref>

	"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />		"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />
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	"All geophysical techniques are based on detection of differences between properties of geologic materials. If such differences do not exist, geophysical methods will not be useful. These differences range from acoustic velocities to contrasts in electric properties of materials. Seismic methods, both reflection and refraction, depend on the difference in compressional or shear-wave velocities through different materials. Electrical methods depend on contrasts in electrical resistivities. Differences in density of different materials allow magnetic surveying to be used. Differences in magnitude of naturally existing electric current within the earth can be detected by self-potential surveys."<ref name="EarthManualP1" />		"All geophysical techniques are based on detection of differences between properties of geologic materials. If such differences do not exist, geophysical methods will not be useful. These differences range from acoustic velocities to contrasts in electric properties of materials. Seismic methods, both reflection and refraction, depend on the difference in compressional or shear-wave velocities through different materials. Electrical methods depend on contrasts in electrical resistivities. Differences in density of different materials allow magnetic surveying to be used. Differences in magnitude of naturally existing electric current within the earth can be detected by self-potential surveys."<ref name="EarthManualP1" />

	==[[Best Practices Resources]]==		==<noautolinks>Best Practices Resources</noautolinks>==
	~~{{Document Icon}} [[Earth Manual Part 1 \| Earth Manual Part 1 (USBR, 1998)]]~~
	~~{{Document Icon}} [[Test Quarrier and Test Fills (EM 1110-2-2301) \| Test Quarries and Test Fills (EM 1110-2-2301) (USACE, 1994)]]~~
	{{Document Icon}} [[Design of Small Dams \| Design of Small Dams (USBR, 1987)]]		{{Document Icon}} [[Design of Small Dams \| Design of Small Dams (USBR, 1987)]]
	{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations (NRCS, 2012)]]		{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations (NRCS, 2012)]]
	~~{{Document Icon}} [[Engineering Geology Field Manual 2nd Edition, Volume 2 \| Engineering Geology Field Manual 2nd Edition, Volume 2 (USBR, 2001)]]~~
	{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) (USACE, 1995)]]		{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) (USACE, 1995)]]

Grichards at 05:25, 18 November 2022

2022-11-18T05:25:47Z

← Older revision		Revision as of 05:25, 18 November 2022
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	<!-- Delete any sections that are not necessary to your topic. Add pictures/sections as needed -->		<!-- Delete any sections that are not necessary to your topic. Add pictures/sections as needed -->
	__NOTOC__		__NOTOC__
			[[Category:Geotechnical Exploration]]
	----		----
	{{Picture		{{Picture

Rmanwaring at 21:43, 2 November 2022

2022-11-02T21:43:00Z

← Older revision		Revision as of 21:43, 2 November 2022
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	==[[Best Practices Resources]]==		==[[Best Practices Resources]]==
	{{Document Icon}} [[Earth Manual Part 1 \| Earth Manual Part 1 (USBR, 1998)]]		{{Document Icon}} [[Earth Manual Part 1 \| Earth Manual Part 1 (USBR, 1998)]]
			{{Document Icon}} [[Test Quarrier and Test Fills (EM 1110-2-2301) \| Test Quarries and Test Fills (EM 1110-2-2301) (USACE, 1994)]]
			{{Document Icon}} [[Design of Small Dams \| Design of Small Dams (USBR, 1987)]]
			{{Document Icon}} [[National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations \| National Engineering Handbook: Chapter 2 - Engineering Geologic Investigations (NRCS, 2012)]]
			{{Document Icon}} [[Engineering Geology Field Manual 2nd Edition, Volume 2 \| Engineering Geology Field Manual 2nd Edition, Volume 2 (USBR, 2001)]]
			{{Document Icon}} [[Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) \| Geophysical Exploration for Engineering and Environmental Investigations (EM 1110-1-1802) (USACE, 1995)]]

	<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->		<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->

Rmanwaring at 21:34, 2 November 2022

2022-11-02T21:34:04Z

← Older revision		Revision as of 21:34, 2 November 2022
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	{{Picture		{{Picture
	<!-- Add image file name (ex.image.jpg) -->		<!-- Add image file name (ex.image.jpg) -->
	\|image=		\|image= RemoteSensing.jpg
	<!--Add link if applicable -->		<!--Add link if applicable -->
	\|link=		\|link=
	<!-- Add picture caption -->		<!-- Add picture caption -->
	\|caption=		\|caption= Aircraft Used for Remote Sensing
	}}		}}

Rmanwaring at 00:26, 2 November 2022

2022-11-02T00:26:02Z

← Older revision		Revision as of 00:26, 2 November 2022
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	*electrical,		*electrical,
	*magnetic, and		*magnetic, and
	*gravity.<ref name="EarthManualP1">[[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]</ref>		*gravity."<ref name="EarthManualP1">[[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]</ref>

	"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />		"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />

Rmanwaring at 00:25, 2 November 2022

2022-11-02T00:25:29Z

← Older revision		Revision as of 00:25, 2 November 2022
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	==[[Best Practices Resources]]==		==[[Best Practices Resources]]==
	{{Document Icon}} [[Earth Manual Part 1 \| Earth Manual Part 1, USBR, 1998]]		{{Document Icon}} [[Earth Manual Part 1 \| Earth Manual Part 1 (USBR, 1998)]]

	<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->		<!-- In the location of an in text citation, simply enclose the citation as follows: <ref> citation </ref>. Citations will automatically populate. Learn more at https://www.mediawiki.org/wiki/Help:Cite. -->

Rmanwaring: Created page with " NOTOC ---- {{Picture |image= |link= |caption= }} "Geophysical methods of subsurface exploration are an indirect means of gathering data pertaining to underground conditions. Using geophysical techniqu..."

2022-11-02T00:24:52Z

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"Geophysical methods of subsurface exploration are an indirect means of gathering data pertaining to underground conditions. Using geophysical techniques involves taking measurements at the earth's surface or in boreholes to determine subsurface conditions. Geophysical methods may be employed during any stage of an investigation and include:

*[[seismic]],
*electrical,
*magnetic, and
*gravity.<ref name="EarthManualP1">[[Earth Manual Part 1 | Earth Manual Part 1, USBR, 1998]]</ref>

"Geophysical methods can be a useful and economic addition when used in conjunction with a test-boring investigation program. In contrast to borings, geophysical surveys are used to explore large areas rapidly and economically. They indicate average conditions along an alignment or in an area, rather than along the restricted vertical line at a single location as in a boring. Geophysical data can be used to help determine the best location of future [[drill]] holes as well as provide information to extrapolate foundation conditions between existing drill holes. These data are useful for detecting irregularities in bedrock surfaces and at interfaces between strata. The cost of performing geophysical surveys is often less than the cost of [[drilling]]; therefore, judicious use of both geophysical methods and drilling can produce the desired information at an overall lesser cost. Although geophysical field work is relatively inexpensive, interpretation of results is difficult and specialized. For test results to be usable and reliable, correlations must necessarily be made locally with exploration data from borings."<ref name="EarthManualP1" />

"Geophysical methods are best suited to prospecting sites for dams, [[reservoirs]], [[tunnels]], highways, [[canals]], and other structures. Also, they have been used to locate gravel deposits and sources of other [[construction]] materials whose properties differ significantly from adjacent [[soils]]. Downhole, uphole, and cross-hole seismic surveys are used extensively to determine dynamic properties of soil and rock at small strains."<ref name="EarthManualP1" />

"All geophysical techniques are based on detection of differences between properties of geologic materials. If such differences do not exist, geophysical methods will not be useful. These differences range from acoustic velocities to contrasts in electric properties of materials. Seismic methods, both reflection and refraction, depend on the difference in compressional or shear-wave velocities through different materials. Electrical methods depend on contrasts in electrical resistivities. Differences in density of different materials allow magnetic surveying to be used. Differences in magnitude of naturally existing electric current within the earth can be detected by self-potential surveys."<ref name="EarthManualP1" />

==[[Best Practices Resources]]==
{{Document Icon}} [[Earth Manual Part 1 | Earth Manual Part 1, USBR, 1998]]


{{Citations}}


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