Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

The Lane Field Property, located northwest of the intersection of Broadway and Pacific Highway on the San Diego Bay Embarcadero in downtown San Diego, California is slated for development of a 40-story, mixed-use, retail/hotel with two subterranean parking levels. Site conditions posed several challenges during the design and implementation of the geotechnical and geologic fault studies. The 6.2-acre site was reclaimed by dredge fill from San Diego Bay in approximately 1900 by the City of San Diego. Prior to 1900, the bay shoreline coincided approximately with the eastern edge of the property. A baseball park was built at the site in 1936 and was still in use until 1957. The site is currently occupied by an asphalt-paved parking lot. A detailed fault evaluation was required because the site is within the City of San Diego Downtown Special Fault Zone; however, fault trenching was not feasible due to the presence of thick, unconsolidated hydraulic fill and a shallow water table. To explore the site for faulting, Geocon conducted three seismic-reflection traverses within the project area. The S-wave reflection technique was chosen for its high signal-to-noise ratio and its ability to detect small offsets in the stratigraphy underlying the site. Geocon also performed 16 cone penetrometer test (CPT) soundings at approximate 50-foot intervals along the seismic traverses to aid the geophysicist with interpretation of the reflection data. We encountered some anomalies in the reflection data. An additional 13 CPTs were advanced at approximate 10-foot intervals over areas of anomalous data indicated by the seismic reflections. The City of San Diego requested an additional 12 CPT soundings at several other locations. The data from three seismic-reflection traverses, forty CPT soundings, and five small-diameter borings indicate the presence of an un-faulted, continuous marker bed within the Pleistocene-aged sediments underlying the site, leading to the conclusion that the site is not affected by active or potentially active faulting.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

Share

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May 24th, 12:00 AM May 29th, 12:00 AM

San Diego Seismic Study – Lane Field

San Diego, California

The Lane Field Property, located northwest of the intersection of Broadway and Pacific Highway on the San Diego Bay Embarcadero in downtown San Diego, California is slated for development of a 40-story, mixed-use, retail/hotel with two subterranean parking levels. Site conditions posed several challenges during the design and implementation of the geotechnical and geologic fault studies. The 6.2-acre site was reclaimed by dredge fill from San Diego Bay in approximately 1900 by the City of San Diego. Prior to 1900, the bay shoreline coincided approximately with the eastern edge of the property. A baseball park was built at the site in 1936 and was still in use until 1957. The site is currently occupied by an asphalt-paved parking lot. A detailed fault evaluation was required because the site is within the City of San Diego Downtown Special Fault Zone; however, fault trenching was not feasible due to the presence of thick, unconsolidated hydraulic fill and a shallow water table. To explore the site for faulting, Geocon conducted three seismic-reflection traverses within the project area. The S-wave reflection technique was chosen for its high signal-to-noise ratio and its ability to detect small offsets in the stratigraphy underlying the site. Geocon also performed 16 cone penetrometer test (CPT) soundings at approximate 50-foot intervals along the seismic traverses to aid the geophysicist with interpretation of the reflection data. We encountered some anomalies in the reflection data. An additional 13 CPTs were advanced at approximate 10-foot intervals over areas of anomalous data indicated by the seismic reflections. The City of San Diego requested an additional 12 CPT soundings at several other locations. The data from three seismic-reflection traverses, forty CPT soundings, and five small-diameter borings indicate the presence of an un-faulted, continuous marker bed within the Pleistocene-aged sediments underlying the site, leading to the conclusion that the site is not affected by active or potentially active faulting.