Serving professionals in engineering, environmental, and groundwater geology
since 1957

OCTOBER MEETING NOTICE
***Tuesday, October 8, 2013***

Topic: "Tunnel Mapping and Comparison of Design vs. Actual Ground Conditions, Caldecott Tunnel Fourth Bore, Oakland, California"

Speaker: Sean P. Harvey, PG, CEG
BRIERLEY ASSOCIATES

Location: Victorio's Ristorante
10901 Victory Blvd
North Hollywood
(818) 762- 9000

Date/Time: Tuesday, October 8, 2013
5:45pm - Social Hour
6:45pm - Dinner
7:45pm - Program

Cost: $30 per person with reservations in advance for AEG members, $35 Non-Members and AEG members without reservations (at the door), $15 for students with a valid student ID.

RSVP: Please email Edmond Lee at: edmond@geoconceptsinc.com
or call (818) 994-8895 ext.103.

Please make reservations by e-mail or call in to Edmond Lee prior to 4 p.m., Monday, October 7th, 2013


Abstract
The Caldecott Tunnel Fourth Bore was mined using the Sequential Excavation Method (SEM) of tunneling. The SEM involves an observational approach to tunneling in which experienced geologists are utilized to map tunnel advances, evaluate ground behavior and recommend primary and secondary ground support based on actual ground conditions as they are encountered. The tunnel, situated approximately one mile east of the active Hayward Fault, transects the northwest-trending Berkeley Hills that are bounded on the west by the Hayward fault and on the east by the Calaveras fault. The Berkeley Hills consist of a complex series of northwest-trending folds and faults developed in Tertiary sedimentary shale, claystone, chert, siltstone, and sandstone, with lesser occurrences of limestone, dolomite, and igneous and sandstone intrusions. These moderately well-stratified, steeply dipping deposits have been folded into northwest-trending folds that are bisected by north-trending faults. The SEM design for this project identified 18 Rock Mass Types (RMT) grouped into seven Ground Classes that correlate directly with seven design Support Categories. Selection of Support Category was implemented by an interactive decision-making process between the Contractor’s and the Owner’s geologists on a daily basis. Initial agreement established at the tunnel heading was typically approved during daily SEM meetings. This presentaton gives an overview of the design RMT’s, Ground Classes and Support Categories, followed by a discussion from the Contractor’s geologists’ perspective that compares the design basis and actual observed geologic conditions, ground behavior and initial support during construction. Tunnel construction resulted in a significantly different distribution of Ground Classes than the design.
 
Speaker Biography
Mr. Harvey is a professional engineering geologist with over thirteen years of progressive experience in geotechnical and geologic engineering applications for tunneling, mining, and commercial construction. Mr. Harvey’s experience in tunneling, underground construction, and mining includes responsibility for subsurface investigations, tunnel design evaluations, Geotechnical Baseline Report (GBR) preparation, geologic mapping, tunnel mapping, ground anchor design and construction, and deep / shallow foundation design and construction. He has also served as a project geologist / engineer for tunnel design and construction management projects. Mr. Harvey has worked on multiple projects in various locations throughout the United States involving soft ground, hard rock, and mixed face conditions. Technical skills obtained through these projects include drilling and coring methods of subsurface exploration, in-situ and laboratory testing methods, geologic mapping and map interpretation, groundwater monitoring and modeling, rock mechanics investigations and interpretations, instrumentation installation and interpretation techniques, report preparation, and design methods and techniques. During excavation of the Caldecott Tunnel 4th Bore, Mr. Harvey served as the contractor’s lead SEM geologist. His responsibilities included mapping the geology as encountered during excavation, documenting rock mass types, ground classes, and describing rock mass behavior, as well as making recommendations for initial support.