Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-4-2013

Abstract

A massive urban excavation is required to construct the below-grade rail platforms for the Transbay Transit Center. A performance-based approach was used to design the minimum stiffness of the shoring system to limit excavation-induced ground movements to appropriate magnitudes and minimize impact to adjacent infrastructure. During construction, a fully-automated near real-time digital geotechnical monitoring system that integrates wireless sensor data streams into an integrated database and decision support system called the Global Analyzer is used to track the performance of this excavation. Instrumentation used for monitoring includes inclinometers, deep settlement markers, extensometers, piezometers, and an automated total station network. Some of the advantages of the Global Analyzer system include (a) integration of all project monitoring data and construction history information in a centralized database, (b) the ability to compare measured and estimated or target performance, (c) the use of early indicators to understand problems areas prior to excavation reaching critical stages, (d) the distribution of geotechnical monitoring data to adjacent building owners and other stakeholders through a web-based portal, and (e) the generation of computer generated email alerts when threshold values are exceeded by a given instrument. The Global Analyzer is a key tool in supporting an efficient decision process informed by more complete and timely performance data. It represents a component of the decision support process needed in the observational approach and deformation control. This application is relatively new to such a large scale project in the US and provides an example of a large complex data collection and distribution system. The monitoring process used for this project takes advantage of the latest communications technologies in the monitoring of the construction of the Transbay Transit Center excavation in its complex urban environment.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

Share

 
COinS
 
Apr 29th, 12:00 AM May 4th, 12:00 AM

Networked Geotechnical Near Real-Time Monitoring for Large Urban Excavation Using Multiple Wireless Sensors

Chicago, Illinois

A massive urban excavation is required to construct the below-grade rail platforms for the Transbay Transit Center. A performance-based approach was used to design the minimum stiffness of the shoring system to limit excavation-induced ground movements to appropriate magnitudes and minimize impact to adjacent infrastructure. During construction, a fully-automated near real-time digital geotechnical monitoring system that integrates wireless sensor data streams into an integrated database and decision support system called the Global Analyzer is used to track the performance of this excavation. Instrumentation used for monitoring includes inclinometers, deep settlement markers, extensometers, piezometers, and an automated total station network. Some of the advantages of the Global Analyzer system include (a) integration of all project monitoring data and construction history information in a centralized database, (b) the ability to compare measured and estimated or target performance, (c) the use of early indicators to understand problems areas prior to excavation reaching critical stages, (d) the distribution of geotechnical monitoring data to adjacent building owners and other stakeholders through a web-based portal, and (e) the generation of computer generated email alerts when threshold values are exceeded by a given instrument. The Global Analyzer is a key tool in supporting an efficient decision process informed by more complete and timely performance data. It represents a component of the decision support process needed in the observational approach and deformation control. This application is relatively new to such a large scale project in the US and provides an example of a large complex data collection and distribution system. The monitoring process used for this project takes advantage of the latest communications technologies in the monitoring of the construction of the Transbay Transit Center excavation in its complex urban environment.