An investigation of standard penetration test hammer efficiency through measurement of impact velocity and stress wave energy
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Miller, Kurtis Henry
issued: 2022-05-04T17:09:44Z
issued: 2022
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: This thesis presents a study of SPT hammer efficiency measurement methods in a set of innovative underground test chambers. The standard stress wave method of hammer efficiency measurement was used alongside hammer impact velocity measurement to create a new database of 1,263 automatic hammer SPT blows. These data were collected with drill rod lengths of 8.5, 16.2 and 32 m. Previous researchers have concluded that estimating SPT hammer efficiency by measuring impact velocity gives equal or slightly better uncertainty in N₆₀ at a lower cost than direct stress wave measurement. The collected dataset confirms this conclusion. Impact velocity is shown to be a reliable indicator of stress wave energy. Measurement of impact velocity is shown to be an attractive complement (if not full replacement) to direct stress wave measurement due to lower measurement uncertainty and the method’s relative simplicity. The hammer impact velocity is measured with a string potentiometer, a high-speed camera, and proprietary sensors integral to a commercially available automatic SPT hammer (the eSPT from MARL Technologies). The stress wave energy is measured using two different devices, the SPT Analyzer (PDI Inc.) and another from Northwoods Instruments. Using two different stress wave devices shows the inherent uncertainty in SPT stress wave measurement. This uncertainty is best seen with the 16.2 m drill rod, where the two devices produced a 5.2% difference in average ETR. The entire dataset has an average post-impact efficiency (e2, stress wave energy divided by impact kinetic energy) of 96.4% (1,263 blows, standard deviation = 4.0%). With this hammer, applying a 96.4% correction to the measured impact velocity will provide a better estimate of ETR than direct measurement. The same logic should apply to all automatic hammers if a tool for impact velocity measurement is available. The innovative test site used to collect these data has several benefits to traditional research methods. Th…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/81466
note: AN INVESTIGATION OF STANDARD PENETRATION TEST HAMMER EFFICIENCY THROUGH MEASUREMENT OF IMPACT VELOCITY AND STRESS WAVE ENERGY by Kurtis Henry Miller B.A.Sc., The University of British Columbia, 2020 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Civil Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) May 2022 © Kurtis Henry Miller, 2022 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: AN INVESTIGATION OF STANDARD PENETRATION TEST HAMMER EFFICIENCY THROUGH MEASUREMENT OF IMPACT VELOCITY AND STRESS WAVE ENERGY submitted by KURTIS HENRY MILLER in partial fulfillment of the requirements of the degree of Master of Applied Science. Dr. Dwayne Tannant, School of Engineering Supervisor Dr. Christopher Ryan Daniel, BC Hydro Co-Supervisor Dr. Sumi Siddiqua, School of Engineering Supervisory Committee Member Dr. John A. Howie, Department of Civil Engineering University Examiner iii Abstract This thesis presents a study of SPT hammer efficiency measurement methods in a set of innovative underground test chambers. The standard stress wave method of hammer efficiency measurement was used alongside hammer impact velocity measurement to create a new database of 1,263 automatic hammer SPT blows. These data were collected with drill rod lengths of 8.5, 16.2 and 32 m. Previous researchers have concluded that estimating SPT hammer efficiency by measuring impact velocity gives equal or slightly better uncertainty in N60 at a lower cost than direct stress wave measurement. The collected dataset confirms this conclusion. Impact velocity is shown to be a reliable indicator of stress wave energy. Measurement of impact velocity is shown to be an attractive complement (if not full replacement) to direct stress wave measurement due to lower measurement uncertainty and the method’s relati…
has type: Thesis/Dissertation
date issued: 2022-05
is shown at: 10.14288/1.0413223
language: eng
degree discipline: Civil Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution 4.0 International
rights URI: http://creativecommons.org/licenses/by/4.0/
scholar level: Graduate
contributor: Tannant, Dwayne
type: Text
type: Dataset
type: Other
identifier URI: http://hdl.handle.net/2429/81466