Abstract
An open gripper TBM continuously records gripper forces. This enables to determine the rock mass stiffness of the surrounding ground by using the gripper as the pressure unit of a plate load test. The gripper tests have been executed in the exploratory tunnel of the Brenner Base Tunnel project in Austria. Two different in situ test procedures have been developed upon constant agreement with the owner, the construction company and the site supervision team of the project. Evaluation of the rock mass stiffness (deformation moduli) indicated good agreement with the characteristic stiffness values for the rock mass from the lab tests. Numerical studies have been executed to validate the depth of influence for the gripper tests. The in situ test data and the results of the gripper test evaluations are discussed and an interpretation on the meaningfulness of the different results are given. Finally, suggested modifications on the gripper-TBM and an outlook on further research requirements on the evaluation of the monitored gripper data are given.
Original language | English |
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Publication status | Published - 1 Jan 2020 |
Event | 54th U.S. Rock Mechanics/Geomechanics Symposium - Virtual, Online, United States Duration: 28 Jun 2020 → 1 Jul 2020 |
Conference
Conference | 54th U.S. Rock Mechanics/Geomechanics Symposium |
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Country/Territory | United States |
City | Virtual, Online |
Period | 28/06/20 → 1/07/20 |
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics
- Geotechnical Engineering and Engineering Geology