Location
San Diego, California
Presentation Date
27 May 2010, 7:30 pm - 9:00 pm
Abstract
For moderately loaded structures founded on liquefiable soils, spread footings on improved ground can provide considerable cost savings over deep foundation options. Liquefaction mitigation by ground improvement must be properly designed and executed; and should include a field verification program. Although densification is the most effective method of achieving verifiable mitigation of liquefaction susceptible soils, vibro-densification methods are often disregarded for urban sites due to concern for adjacent structures and utilities. An alternative to vibratory methods is compaction grouting, which can achieve densification of cohesionless materials while avoiding excessive vibration of adjacent structures. Recently, compaction grouting was successfully applied to densify a thick loose sand layer (up to 40 feet) for a large development site in an urban environment. This densification significantly increased the factor of safety against liquefaction and reduced potential liquefaction-induced settlement to under 0.5 inch. The compaction grouting program included automated data acquisition and processing and three-dimensional visualization components to ensure quality control and assurance. In addition, the site improvement program was fully verifiable, as the ground improvement program included a comparison of cone penetrometer tests (CPT) conducted prior to and following treatment. Although compaction grouting has been well utilized for several years, the potential for liquefaction mitigation in urban environments is not well established. However, ground improvement through compaction grouting can be a cost-effective alternative to drilled shafts or driven piles on liquefiable sites. This paper includes a description of the site conditions, the compaction grouting program (including automated data acquisition instrumentation and visualization), site instrumentation, post-treatment evaluation of the mitigation procedures, and analysis of the response of adjacent structures.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
5th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Publisher
Missouri University of Science and Technology
Document Version
Final Version
Rights
© 2010 Missouri University of Science and Technology, 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
Wakeman, Richard C.; Evenson, Alan; Morgan, Thomas; Pastore, Joseph; and Blackburn, J. Tanner, "Compaction Grouting for Seismic Mitigation of Sensitive Urban Sites" (2010). International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. 3.
https://scholarsmine.mst.edu/icrageesd/05icrageesd/session09/3
Included in
Compaction Grouting for Seismic Mitigation of Sensitive Urban Sites
San Diego, California
For moderately loaded structures founded on liquefiable soils, spread footings on improved ground can provide considerable cost savings over deep foundation options. Liquefaction mitigation by ground improvement must be properly designed and executed; and should include a field verification program. Although densification is the most effective method of achieving verifiable mitigation of liquefaction susceptible soils, vibro-densification methods are often disregarded for urban sites due to concern for adjacent structures and utilities. An alternative to vibratory methods is compaction grouting, which can achieve densification of cohesionless materials while avoiding excessive vibration of adjacent structures. Recently, compaction grouting was successfully applied to densify a thick loose sand layer (up to 40 feet) for a large development site in an urban environment. This densification significantly increased the factor of safety against liquefaction and reduced potential liquefaction-induced settlement to under 0.5 inch. The compaction grouting program included automated data acquisition and processing and three-dimensional visualization components to ensure quality control and assurance. In addition, the site improvement program was fully verifiable, as the ground improvement program included a comparison of cone penetrometer tests (CPT) conducted prior to and following treatment. Although compaction grouting has been well utilized for several years, the potential for liquefaction mitigation in urban environments is not well established. However, ground improvement through compaction grouting can be a cost-effective alternative to drilled shafts or driven piles on liquefiable sites. This paper includes a description of the site conditions, the compaction grouting program (including automated data acquisition instrumentation and visualization), site instrumentation, post-treatment evaluation of the mitigation procedures, and analysis of the response of adjacent structures.
