Location
Chicago, Illinois
Date
01 May 2013, 2:00 pm - 4:00 pm
Abstract
Prior to the excavation of half a million cubic meters of dense gravelly material within the city centre of Milan, a 24 to 27m long diaphragm wall was built to provide a 17m retained height to a four-level basement. Temporary support was offered by two to four rows of ground anchors with the exception of a portion adjacent to an existing multi-level cark park where a post-tensioned capping beam was installed to protect the car park and prevent it from being subject to sway. Other design challenges were posed by the proximity of a buried channel and of an urban rail tunnel. An extensive monitoring system was set up including inclinometers, load cells and topographical survey points to reveal lateral movements in the order of 10mm or less, negligible variation of anchor loads as the excavation progressed and heave behind the wall. In response to a general lack of case histories and design guidance on deep excavations in dense coarse material, especially in the region, a backanalysis of diaphragm wall monitoring data was carried out and its main results are commented on in the present paper. Lateral movements are best reproduced with pseudo-FE or full FE software if a soil stiffness compatible with the relevant shear strain level is adopted.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
7th Conference of the International Conference on Case Histories in Geotechnical Engineering
Publisher
Missouri University of Science and Technology
Document Version
Final Version
Rights
© 2013 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
Petrella, Francesco; Persio, Roberto; Ferrero, Silvia; and Hocombe, Tim, "Behaviour of a Large Anchored Basement in Dense Sands and Gravels" (2013). International Conference on Case Histories in Geotechnical Engineering. 8.
https://scholarsmine.mst.edu/icchge/7icchge/session01/8
Behaviour of a Large Anchored Basement in Dense Sands and Gravels
Chicago, Illinois
Prior to the excavation of half a million cubic meters of dense gravelly material within the city centre of Milan, a 24 to 27m long diaphragm wall was built to provide a 17m retained height to a four-level basement. Temporary support was offered by two to four rows of ground anchors with the exception of a portion adjacent to an existing multi-level cark park where a post-tensioned capping beam was installed to protect the car park and prevent it from being subject to sway. Other design challenges were posed by the proximity of a buried channel and of an urban rail tunnel. An extensive monitoring system was set up including inclinometers, load cells and topographical survey points to reveal lateral movements in the order of 10mm or less, negligible variation of anchor loads as the excavation progressed and heave behind the wall. In response to a general lack of case histories and design guidance on deep excavations in dense coarse material, especially in the region, a backanalysis of diaphragm wall monitoring data was carried out and its main results are commented on in the present paper. Lateral movements are best reproduced with pseudo-FE or full FE software if a soil stiffness compatible with the relevant shear strain level is adopted.
