NTL Record

Title A New Sensing System for Pre-excavation Subsurface Investigation for Tunnels in Rock Masses. Volume I. Feasibility Study and System Design
Record ID 57978
Personal Name
Creator
Rubin, L. A.; Fowler, J. C.; Griffin, J. N.; Still, W. L.
Corporate Creator United States. Federal Highway Administration; ENSCO, Inc
Publisher United States. Federal Highway Administration
Publication Date 19760800
Language English
Abstract This report includes a feasibility study and system design for an initial prototype of a sensing system for pre-excavation subsurface investigation for tunnels in rock. Tunnels in rock are very expensive, and costs often rise far above estimates when unforeseen problems are encountered during excavation. New techniques in rapid excavation technology, such as the development of boring machines, have increased the need for improved site investigation. Possibilities for a new sensing system that will provide more complete data on subsurface conditions were investigated. Favorable results obtained from high-resolution geophysical sensing in boreholes have been combined with improvements in drilling of long, horizontal, precise boreholes in order to provide an economical alternative to pilot tunnel for subsurface investigation. Pilot tunnel costs as with all subsurface construction are rising at rates much higher than the economy, thus the use of borehole site investigation has potentially very high benefit/cost characteristics. The prototype system designed is a highly mobile geophysical measurement (data acquisition) system. The system will take electromagnetic radar measurements, pulsed acoustical measurements, and multi-spaced array resistivity measurements. The sensors will be used in traverses along the borehole, and data will be taken and stored on magnetic tape for subsequent reduction and analysis at a computational center. The system could reduce accidents, reduce bid contingencies, and reduce other factors contributing to rapid escalating costs of subsurface excavation. Volume I describes the feasibility study and system design. Volume II contains the Appendices A-R.
Rosap ID dot:30587
Rosap URL https://rosap.ntl.bts.gov/view/dot/30587
TRT Terms Acoustic detectors; Acoustic emission; Analysis; Boreholes; Construction; Costs; Data collection; Excavation and tunneling; Functional analysis; Geological events; Geological surveying; Radar; Rocks; Seismic prospecting; Seismicity; Surveys; Tunneling; Materials
Geographical
Coverage
United States
TRIS Online
Accession No
00174740
Contract Number DOT-FH-11-8602
Report Number FHWA-RD-77- 10 Final Rpt., 1061-TR-3-1-Vol-1
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/57000/57900/57978/newsensingsystem00rubi.pdf
Format PDF
Database NTL Digital Repository