7/30/2019 36b Developing an ASTM Standard for the Utility Dynamic Cone Penetrometer FinalReport 2-Pager

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EXCAVATION & SITE RESTORATIONPROJ ECT No. 3.6.b

SUMMARY REPORT

P r o je c t D e s c r i p t i o n

Gas utilities have long recognized the need for qualitycontrol of soil compaction to improve pavement resto-ration and reduce call-backs from failed sections.

For several years, the Utility Dynamic Cone Penetro-meter (DCP) has been used for soil-compaction controlduring utility restoration work. Field demonstrationshave shown the DCP to be an effective quality-controldevice that is less expensive than the more commonlyused and accepted nuclear density gauge. However, theeconomic benefits that could be derived from the DCPwere limited without an American Society of Testingand Materials (ASTM) procedure for its standard use.

Through this project, researchers developed a standardwhich gained regulatory approval.

As part of the program, utilities performed demonstra-tions of the Utility DCP for New York City agenciesand Department of Transportation regulators to showthe potential of the DCP as a cost-effective alternative

to the nuclear density gauge.

In t his project, researchers developed an ASTM standard and test ing procedure forthe use of the Uti lit y Dynamic Cone Penetrometer (DCP), a tool t hat has been show nto be an effective and less expensive alternative to other techn olog ies used to ensureproper soil compaction.

Developing an ASTM Standard forthe Utility Dynamic Cone Penetrometer

De l i v e r a b l e

A published ASTM standard procedure for the use andoperation of the Utility DCP was the final deliverable

of this project.

Bene f i t s

The development of an ASTM standard procedure forUtility DCP compaction control will establish the toolas an acceptable technology to replace the nucleardensity gauge in utility pavement restoration work.

The cost of the nuclear density gauge is about $6,200,compared to about $400 for the DCP (plus an additionalcost for optional electronic data-collection add-ons).Further costs with the nuclear density gauge are en-countered for licensing, training, maintenance, and dis-posal.

A 2002 study shows that the natural gas industryperforms about 722,000 bellhole excavations per year.

At an average cost of $250 to $300 per repair for bell-holes and $3,500 per 100 feet of trench, utilities willrealize substantial savings by establishing an economicprocedure for compaction control and by eliminatingthe need of using the costly nuclear density gauge inprotected streets.

T e c h n ic a l C o nc e p t & A p p ro a c h

The Utility DCP uses a five-pound drop-weight todrive a small cone into the soil, counting the number ofdrops required to penetrate the soil a fixed distance of

3- inches. The number of drops is determined by cali-brating the device to the relative soil compaction ofvarious soil types. Researchers report that in earliertests the device proved to be a practical replacement forthe nuclear density gauge by providing layer-by-layercompaction verification.

Previous work in a GTI Research Collaboration Project(2002-2004) resulted in evaluating and selecting theDCP as one of the three best tools for utility work. Afollowing OTD project (2004-2006) included modify-

Research has shown the Utili ty Dynamic Cone Pentrometer to be an

attractive, cost-saving alternative to more commonly used soil-

compaction-measurement equipment.

7/30/2019 36b Developing an ASTM Standard for the Utility Dynamic Cone Penetrometer FinalReport 2-Pager

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ing the DCP to improve its quality, overall effective-ness, and to add electronic data storage and transfercapabilities.

Work in this project included the initiation of a standardrequest to ASTM Committee on Soils and Rock (ASTMD-18). A case study was presented to ASTM supportingthe need to establish the procedure.

The ASTM procedure required voting and approval ofthe draft standard and discussion during the ASTMcommittee meetings. (ASTM committees meet twice ayear to discuss the proposed drafts. A new standard mayrequire an average of two to three years before it isapproved for publication.)

Res u l t s / S t a t u s

This project is now complete.

The project team drafted a proposed ASTM standard,which passed the main committee ballot in January2008. Investigators subsequently addressed commentsand negative votes from ASTM members.

ASTM issued the formal reference standard in June2008 as ASTM D 7380-08 Standard Test Method forSoil Compaction Determination at Shallow Depth Us-ing 5-lb (2.3 kg) Dyname Cone Penetrometer.

F o r m o r e in f o rm a t i o n :

Maureen Droessler

Program AdministratorOperations Technology Development, NFPPhone: 847/768-0608maureen.droessler@otd-co.org

Schematic of the Dynamic Cone Penetrometer.