Location
San Diego, California
Presentation Date
29 Mar 2001, 7:00 pm - 7:30 pm
Abstract
To improve our understanding of the lateral load behavior of deep foundations in liquefied soil, a series of full-scale lateral load tests have been performed at the National Geotechnical Experimentation Site (NGES) at Treasure Island in San Francisco, California. The ground around the test piles was liquefied using explosives prior to lateral load testing. The goal of the project is to develop load-displacement relationships for bored and driven piles and pile groups in liquefied sand under full-scale conditions for improved and non-improved ground. The results of this investigation confirmed that controlled blasting techniques could successfully be used to induce liquefaction in a well-defined, limited area for field-testing purposes. Excess pore pressure ratios greater than 0.8 were typically maintained for 4 to 10 minutes after blasting. Data were collected showing the behavior of laterally loaded piles before and after liquefaction in non-improved ground. Following liquefaction, the stiffness of the soil-foundation system typically decreased by 70 to 80% of its pre-liquefaction value non-improved ground. Ground improvement with stone columns was then performed prior to an additional series of tests. Lateral load tests were again conducted before and after blasting to induce liquefaction. Cone penetration testing following the installation of stone columns found that the density was improved significantly. As a result, the stiffness of the foundation system following blasting was 2.9 to 3.6 times that in the liquefied soil. Subsequent tests involving more than twice as many piles or 50% larger piles provided less than 50% of the increased resistance produced by stone column treatment alone. This study provides some of the first full-scale quantitative results on the improvement of foundation performance due to ground improvement in a liquefiable deposit.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
4th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Publisher
University of Missouri--Rolla
Document Version
Final Version
Rights
© 2001 University of Missouri--Rolla, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Rollins, Kyle M.; Ashford, Scott A.; and Lane, J. Dusty, "Full-Scale Lateral Load Testing of Deep Foundations Using Blast-Induced Liquefaction" (2001). International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. 3.
https://scholarsmine.mst.edu/icrageesd/04icrageesd/session14/3
Included in
Full-Scale Lateral Load Testing of Deep Foundations Using Blast-Induced Liquefaction
San Diego, California
To improve our understanding of the lateral load behavior of deep foundations in liquefied soil, a series of full-scale lateral load tests have been performed at the National Geotechnical Experimentation Site (NGES) at Treasure Island in San Francisco, California. The ground around the test piles was liquefied using explosives prior to lateral load testing. The goal of the project is to develop load-displacement relationships for bored and driven piles and pile groups in liquefied sand under full-scale conditions for improved and non-improved ground. The results of this investigation confirmed that controlled blasting techniques could successfully be used to induce liquefaction in a well-defined, limited area for field-testing purposes. Excess pore pressure ratios greater than 0.8 were typically maintained for 4 to 10 minutes after blasting. Data were collected showing the behavior of laterally loaded piles before and after liquefaction in non-improved ground. Following liquefaction, the stiffness of the soil-foundation system typically decreased by 70 to 80% of its pre-liquefaction value non-improved ground. Ground improvement with stone columns was then performed prior to an additional series of tests. Lateral load tests were again conducted before and after blasting to induce liquefaction. Cone penetration testing following the installation of stone columns found that the density was improved significantly. As a result, the stiffness of the foundation system following blasting was 2.9 to 3.6 times that in the liquefied soil. Subsequent tests involving more than twice as many piles or 50% larger piles provided less than 50% of the increased resistance produced by stone column treatment alone. This study provides some of the first full-scale quantitative results on the improvement of foundation performance due to ground improvement in a liquefiable deposit.
