Location

New York, New York

Session Start Date

4-13-2004

Session End Date

4-17-2004

Abstract

Two case histories are presented where jurisdictional authorities expressed a concern regarding the impact of blast and construction traffic induced vibrations on the stability of the burrows of endangered ground dwelling species. The first case history involved the use of explosives proposed to be used for a seismic survey in the vicinity of desert tortoise burrows. The concern was that the use of explosives in the vicinity of a tortoise burrow could cause the collapse of an occupied burrow potentially trapping the tortoise within the burrow. Field tests were performed by constructing artificial tortoise burrows and inducing progressively higher vibration levels near the test burrows while observing the stability of the burrow. The data obtained from the tests were used to develop a site-specific attenuation relationship and vibration amplitude-burrow collapse relationship. These relationships were used to establish safe distance criteria for the use of explosives. The second case history involved the effect of heavy haul-truck traffic induced vibrations on the stability of San Bernardino Kangaroo Rat (SBKR) burrows. The jurisdictional authority imposed a mitigation area requirement equal to 100-ft. on either side of the almost 2-mile long haul roadway. This resulted in a significant cost impact on the project. Initially, an evaluation was made using the results of the tortoise study for vibration amplitude-burrow stability criteria on the premise that the wide low tortoise burrows would tend to be less stable than the smaller round SBKR burrows. This relationship was used together with attenuation relationships for the heavy haul-trucks considering soil type, the road roughness, truck weight, number of trucks, and trucks speed to evaluate the required mitigation area. The initial analysis indicated that 3-ft. on either side of the roadway would be acceptable to define the mitigation area instead of the 100-ft imposed by the jurisdictional authority. The results of the initial evaluation were discussed with personnel representing the jurisdictional authority and a compromise mitigation distance of 10-ft on either side of the haul road was negotiated, contingent on the results of fieldtesting. The field testing was completed by excavating 36 artificial SBKR burrows along the haul route, inserting split sample tubes into the burrows, monitoring vibrations induced by truck traffic at 5-ft. and 10-ft. from the road, removing the split sample tubes after one hour of truck traffic (25 to 35 trucks), and measuring the volume of soil collected in the split tubes. It was found that less than 10% of the volume of the burrow hole was collected in the sample tubes and the test results were found acceptable by the jurisdictional authority. The paper provides a tabulation of all vibration measurements, photos or diagrams of sampling and test layouts, the basis for estimating vibration amplitudes, and the conclusions reached from each case history.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fifth Conference

Publisher

University of Missouri--Rolla

Publication Date

4-13-2004

Document Version

Final Version

Rights

© 2004 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 13th, 12:00 AM Apr 17th, 12:00 AM

Two Case Histories of Blast- & Traffic-Induced Vibrations on the Stability of Burrows of Endangered Sensitive Ground Dwelling Animals

New York, New York

Two case histories are presented where jurisdictional authorities expressed a concern regarding the impact of blast and construction traffic induced vibrations on the stability of the burrows of endangered ground dwelling species. The first case history involved the use of explosives proposed to be used for a seismic survey in the vicinity of desert tortoise burrows. The concern was that the use of explosives in the vicinity of a tortoise burrow could cause the collapse of an occupied burrow potentially trapping the tortoise within the burrow. Field tests were performed by constructing artificial tortoise burrows and inducing progressively higher vibration levels near the test burrows while observing the stability of the burrow. The data obtained from the tests were used to develop a site-specific attenuation relationship and vibration amplitude-burrow collapse relationship. These relationships were used to establish safe distance criteria for the use of explosives. The second case history involved the effect of heavy haul-truck traffic induced vibrations on the stability of San Bernardino Kangaroo Rat (SBKR) burrows. The jurisdictional authority imposed a mitigation area requirement equal to 100-ft. on either side of the almost 2-mile long haul roadway. This resulted in a significant cost impact on the project. Initially, an evaluation was made using the results of the tortoise study for vibration amplitude-burrow stability criteria on the premise that the wide low tortoise burrows would tend to be less stable than the smaller round SBKR burrows. This relationship was used together with attenuation relationships for the heavy haul-trucks considering soil type, the road roughness, truck weight, number of trucks, and trucks speed to evaluate the required mitigation area. The initial analysis indicated that 3-ft. on either side of the roadway would be acceptable to define the mitigation area instead of the 100-ft imposed by the jurisdictional authority. The results of the initial evaluation were discussed with personnel representing the jurisdictional authority and a compromise mitigation distance of 10-ft on either side of the haul road was negotiated, contingent on the results of fieldtesting. The field testing was completed by excavating 36 artificial SBKR burrows along the haul route, inserting split sample tubes into the burrows, monitoring vibrations induced by truck traffic at 5-ft. and 10-ft. from the road, removing the split sample tubes after one hour of truck traffic (25 to 35 trucks), and measuring the volume of soil collected in the split tubes. It was found that less than 10% of the volume of the burrow hole was collected in the sample tubes and the test results were found acceptable by the jurisdictional authority. The paper provides a tabulation of all vibration measurements, photos or diagrams of sampling and test layouts, the basis for estimating vibration amplitudes, and the conclusions reached from each case history.