Sean Harvey
Mr. Harvey is a licensed professional engineering geologist with experience in geotechnical and geologic engineering applications for underground design and construction, trenchless and tunnel design and construction, mining, and commercial construction. He routinely manages projects for underground design and construction, underground feasibility and design evaluation, initial support design and evaluation, rock mechanics, geotechnical investigations, geologic interpretation, and construction observation.
Mr. Harvey’s experience in underground construction includes responsibility for subsurface investigations, design evaluations, Geotechnical Baseline Report (GBR) preparation, geologic mapping, tunnel mapping, ground anchor design and construction, and deep / shallow foundation design and construction. Mr. Harvey has worked on projects in various locations throughout the United States involving soft ground, hard rock, and mixed face conditions generally located in highly developed, urban areas. 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 underground design methods and techniques.
Relevant Projects
Caldecott 4th Bore Tunnel, Almeda and Contra Costa Counties, CA
Lead Engineering Geologist
2014 Project of the Year Award - California Transportation Foundation
“Project of the Year,” Bay Area Metropolitan Transportation Commission
Caltrans Transportation Excellence Award, 2015 Major Structures Category
Bore No. 4 is located north of the existing Caldecott Tunnel on SR 24 between SR 13 in Oakland, CA and Gateway Boulevard in Orinda, CA. The existing Caldecott Tunnels connect Oakland and Orinda through the Berkeley Hills. The mined tunnel portion of Bore No. 4 is about 990.4m (3249.2-ft) long and has a horseshoe shape with excavated dimensions of approximately 15m (49.2-ft) in width and 11.0 to 12.3 m (36.1- to 40.3-ft) in height. Seven cross passages were mined between Bore No. 4 and the existing Bore No. 3. The horseshoe-shaped cross passages range from 32.7 to 44.1m (107- to 145- ft) long and have excavated dimensions of about 4.2m (13.8-ft) wide and 4.7m (15.4-ft) high. Excavation commenced from two portals using roadheader equipment. Engineering geologic conditions range from highly weathered (near soil) shale under shallow cover to blocky and seamy sandstone under approximately 530-ft of cover.
The design and construction of Bore No. 4 and cross passages was based on the philosophy of the sequential excavation method (SEM). Depending on ground conditions encountered, the initial support system could include: shotcrete, rock dowels, lattice girders, spiles, and grouted steel pipes in various combinations.
Mr. Harvey served as the lead engineering geologist and provided full time, on-site construction phase services including evaluation and documentation of ground conditions, sequential excavation consulting, and initial support recommendations during excavation of the tunnel. Mr. Harvey individually assessed the most ground conditions encountered, and made the most round by round ground support recommendations for daily SEM meetings at which initial support selection was the main topic of discussion.
During the bid and preconstruction phases, Mr. Harvey performed analyses of the anticipated geologic / geotechnical conditions to be encountered during construction and evaluated the contract design documents in order to provide construction recommendations and bid assistance to Tutor-Saliba Corporation. Tutor-Saliba Corp. was the low bidder and was awarded the construction contract. During the preconstruction and submittal phase, Mr. Harvey performed further evaluation of initial support design and anticipated ground characteristics for use in finite element analyses and construction means and methods recommendations.
New Irvington Tunnel, Sunol to Fremont, San Francisco Bay Area, Fremont, CA
Engineering Tunnel Geologist
*Deepest Application of Unreinforced Secant Pile Supported Shaft in North America at the time of construction
The New Irvington Tunnel (NIT) project, located in the San Francisco Bay Area, east of the City of Fremont, CA, involved the construction of a new tunnel, connections to existing facilities at each end of the tunnel, and construction of ancillary facilities. The NIT runs roughly parallel with the Existing Irvington Tunnel (EIT), which was constructed over 80 years ago. The new tunnel, about 3.6 miles long, was excavated in a 12-ft wide by 14-ft tall horseshoe shape using drill-and-blast, mechanical, and hand excavation techniques. Difficult and highly variable ground conditions were encountered during excavation. The rock mass was generally composed of weak, intensely fractured and sheared sedimentary rocks (mainly sandstone, siltstone, interbedded siltstone/sandstone, and shale), and also includes some sections of stronger and more massive rock. Along the proposed alignment, the tunnel will also intercept a number of fault zones with abundant clay gouge. The initial support elements consist of steel sets with timber lagging, rock dowels, spiles, and shotcrete.
Mr. Harvey provided on-site construction phase services including evaluation and documentation of ground conditions and initial support recommendations during excavation of the tunnel. During the bid and preconstruction phases, Mr. Harvey performed an analysis of the anticipated geologic / geotechnical conditions to be encountered during construction and evaluated the contract design documents in order to provide bid assistance, construction recommendations, and initial support submittal preparation to Oscar Renda Contracting.
Purple Line Extension – Section 2, Los Angeles Metropolitan Transportation Authority, STV, Inc., Los Angeles and Beverly Hills, CA
Major Temporary Works Design Group Leader
Design/Build Project Delivery of the second of three planned sections of the Purple Line Extension Transit Project includes 2.59 miles of additional double track heavy rail transit to Metro’s Rail system and two new stations at Wilshire/Rodeo and Century City/Constellation. The two station excavations will be up to approximately 1,100-ft in length and almost 100-ft below ground surface. Given the urban nature of the alignment, station excavations are deep shored open cut with live traffic above. The tunnels and shafts will encounter a variety of challenging conditions including groundwater, hydrocarbons, and faults. Tunneling is being accomplished using two 22-ft diameter Herrenknecht EPB TBM’s
Mr. Harvey served on the design team as Major Temporary Works Design Group Leader. His responsibilities include managing and coordinating the structural design and numerical modeling of the support of excavation, pre-construction surveys for buildings and utilities within the zone of influence, soil and groundwater investigation program, dewatering program, and associated geotechnical parameters to be used in the support of excavation design. Additional responsibilities include oversight of the instrumentation design,ground movement assessments and building and utility settlement impact assessments. He was also responsible for coordination of the temporary support of excavation designs with the permanent structures designs to ensure constructability and project requirements compliance.
Westside Purple Line Extension, Section 3 - Westwood/UCLA and Westwood/VA Hospital Stations Los Angeles Metropolitan Transportation Authority, STV, Inc., Los Angeles and Beverly Hills, CA
Major Temporary Works Design Group Manager
Both station excavations will be up to approximately 1,100-ft in length and almost 100-ft below ground surface. Given the urban nature of the alignment, station excavations are deep shored open cut with live traffic above. The tunnels and shafts will encounter a variety of challenging conditions including groundwater, hydrocarbons, and faults.
Mr. Harvey served on the design team as Major Temporary Works Design Group Leader. His responsibilities include managing and coordinating the structural design and numerical modeling of the support of excavation, pre-construction surveys for buildings and utilities within the zone of influence, soil and groundwater investigation program, dewatering program, and associated geotechnical parameters to be used in the support of excavation design. Additional responsibilities include oversight of the instrumentation design,ground movement assessments and building and utility settlement impact assessments. He was also responsible for coordination of the temporary support of excavation designs with the permanent structures designs to ensure constructability and project requirements compliance.
Bertha TBM Access Shaft, Alaskan Way WR99, Seattle, WA
Lead Engineering Geologist
When complete, this dual stacked freeway within the SR 99 tunnel constructed by the largest ever Earth-Pressure-Balance tunnel boring machine (TBM), will carry over 80,000 vehicles each day. During early December 2013, obstructions and mechanical issues halted tunneling. Brierley Associates was retained by Seattle Tunnel Partners, the design-build joint venture, to design an access shaft that allowed removal of the cutter head assembly from the TBM nicknamed “Bertha”. Secant pile diameters varied between 1.0m and 3.0m. Components of design also included jet grout cutoff walls, dewatering and depressurization under the shaft base and around the 57.5-ft diameter TBM penetration and geotechnical instrumentation. This is the deepest application of secant piles in North America. The prior record was set at the New Irvington Tunnel Vargas Shaft, also designed by Brierley.
Mr. Harvey was in charge of developing the subsurface geologic model, finite element geologic and geotechnical models including the lithology and various input parameters for the design of an 80-ft inside-diameter unreinforced secant pile access shaft (3- to 10 ft diameter piles). Mr. Harvey also assisted with the dewatering analysis and design, provided evaluation and interpretation of the subsurface conditions as encountered during shaft excavation, and interpreted ground behavior based on data derived from an extensive network of geotechnical instruments installed throughout downtown Seattle.
Lake Mead Intake No. 3, Las Vegas, NV
Shaft Design Engineer’s Representative
The Lake Mead Intake No. 3 project includes five major components: a deep-water intake riser and inlet structure; an intake tunnel driven beneath the lake and a portion of Saddle Island; a pumping station on Saddle Island; a discharge pipeline connection to the Alfred Merritt Smith WTF; and a tunnel connecting the IPS-3 facilities with the existing IPS-2. IPS-3’s basic concept is to draw water from below the lake’s thermocline, providing reliable access to better water quality (minimizing the need for additional treatment processes). Main areas of work include a 30-ft diameter, 600-ft deep tunnel access shaft; a secondary shaft to service the access shaft; a TBM-excavated, 20-ft diameter, three mile long intake tunnel beneath the lake; an intake structure in the lake consisting of a caisson structure that was fabricated on the lake surface, immersed into a preformed excavation, and encased in tremie concrete. The intake structure also served as a dock to receive the TBM.
Brierley Associates was retained by Vegas Tunnel Constructors to provide the detailed design for the contract; providing the lead engineer, tunnel design, geotechnical characterization, and specification and submittal review. Excavation of the access shaft and service shaft were accomplished through drill-and-blast excavation methods. Initial support elements consisted of rock dowels and shotcrete followed by a cast-in-place permanent concrete liner. The TBM starter tunnel was excavated using drill-and-blast and mechanical excavation techniques. Initial support of the TBM starter tunnel consisted of steel sets, rock dowels, and shotcrete. Mr. Harvey served as the on-site Shaft Design Engineer’s Representative. Responsibilities included general construction observations and geotechnical / geologic mapping and characterization of the tunnel access shaft, service shaft, and TBM Assembly Cavern and starter tunnel for use in initial support design.
Publications
- Harvey, S.; Zietlow, B.; Kwietnewski, D.; Howard, A., 2014 “Rock Mass Characterization and Initial Support Performance of the Caldecott Tunnel Fourth Bore, San Francisco Bay Area, California”, Proceedings of the 2014 North American Tunneling conference, Los Angeles, CA; June 2014.
- Harvey, S.; Howard, A.; Baldwin, J.; Monahan, W., 2012 “Contractor Implementation of SEM Tunneling and Comparison Between Design and Observed Ground Conditions, Caldecott Tunnel Fourth Bore, San Francisco Bay Area, California” Proceedings of the 2012 North American Tunneling conference, Indianapolis, IN; June 2012.
- Harvey, S.; Ozbay, U., 2009. “Review and Applicability of Yielding Support Systems for Bump Prone Coal Mines in the Western United States” Proceedings of the 2009 Society for Mining, Metallurgy and Exploration Annual Meeting and Exhibit; Denver, CO; February, 2009.
- Harvey, S.; Ozbay, U., Neugebauer, E.; Warfield, B.; Koontz, W.; Anderson, T.; Avery, J. “In-Situ Testing of Roofex Yielding Rock Bolts in Coal Ribs” Proceedings of the 28th International Conference on Ground Control in Mining, Morgantown, WV; July, 2009.
