HARD ROCK TBMs Levent Ozdemir Tunneling Consultant
HARD ROCK TBM TYPES Main-Beam (open, gripper) Single Shield Double Shield
MAIN-BEAM HARD ROCK TBM
MAIN-BEAM HARD ROCK TBM
SINGLE SHIELD CROSS-SECTION
SINGLE SHIELD TBM
DOUBLE-SHIELD CROSS-SECTION 2 3 1
DOUBLE-SHIELD TBM
COMPARISON BETWEEN HARD ROCK TBM TYPES Single shield Double shield Open type For the poorest ground condition Used with pre-cast segments (required for thrust reaction) Pro s Relatively inexpensive Crew not exposed to rock Short shield, less prone to trapping Better steering ability No need of shotcrete Con s Slow advance rates Cyclic operation since machine forces are reacted via tunnel lining (cut/ring build) For poor to medium quality rock May be used with or without pre-cast segments Crew not exposed to rock Can erect lining while boring High advance rates Can operate as a Single Shield in poor ground Expensive Prone to becoming stuck in high overburden Large turn radius Large thrust force required (due to shield friction) For medium to high quality rock, gripper reaction needed to advance machine High advance rates Tight turn radius Inexpensive Easy mob/demob. Crew more exposed to rock Gripper pressure (~4MPa)
TBM SELECTION Very poor rock RQD <25% Poor rock RQD 25-50% Fair rock RQD 50-75% Good rock RQD 75-90% Very good rock RQD 90-100%
EXCAVATION BY HARD ROCK TBMS
DISC CUTTER COMPONENTS
TBM CUTTING FACE
DISC CUTTING
CHIPS GENERATED BY DISC CUTTERS
DISC CUTTER DEVELOPMENT HISTORY Cutter Diameter (in) Cutter Load (lbs.) Year Introduced 13 20,000 1980 14 30,000 1976 15.5 45,000 1973 17 60,000 1983 19 70,000 1989
WHY USE BIGGER CUTTERS?
CUTTER WEAR AND REPLACEMENT
NORMAL WEAR VERY HARD ABRASIVE ROCK
CHIPPING
MECHANICAL FAILURES BLOCKED CUTTERS, BAD BEARINGS OR SEALS
HARD FACING OF DISC CUTTER RINGS (HERRENKNECHT)
CUTTER CHANGE OPERATION
CUTTER CHANGE OPERATION
CUTTER INSTRUMENTATION ( Cutter RPM, temperature and Vibration)
TBM BACKUP SYSTEM Energy supply Transformer Electrical cabinets Cable drum Hydraulic systems Compressed air system TBM operation & guidance systems TBM operators station Laser guidance system Ventilation Main ventilation air ducts Dust suppression system Air cooler Safety system Unobstructed walkways Work platforms Emergency rescue cabin Fire suppression system Fire/gas detection system Rock support Segment/ring erector Segment storage Grouting Drill equipment Material transport Conveyor belt Belt storage and extension Temporary muck storage
MUCK TRANSPORTATION (BELT CONVEYOR) Tunnel Conveyor Installation Tunnel Conveyor
MUCK TRANSPORTATION (RAIL HAULAGE)
TBM ASSEMBLY
PORTAL ASSEMBLY
UNDERGROUND ASSEMBLY
NIAGARA TUNNEL PROJECT ON-SITE ASSEMBLY (OFTA)
COMPLETED TBM ASSEMBLY NIAGARA TUNNEL PROJECT
GROUND SUPPORT
ROCK BOLTING
Wire Mesh Erector WIRE MESH
SHOTCRETE ROBOT
Wire Mesh Erector as Steel Support Erector STEEL SUPPORT Ring Beams
PRE-CAST SEGMENTAL LINING
PRE-EXCAVATION GROUTING
PROBE DRILLING AND PRE-EXCAVATION GROUTING
TBM PERFORMANCE PREDICTION TBM Predictor Model University of Trondheim (NTNU) Model Proprietary Models by Manufacturers
TBM PERFORMANCE PREDICTION AR = ROP x Utilization x Total shift hours AR: Daily advance rate (ft/day) ROP: Rate of Penetration (ft/hr) CL = Cutter life (cubic yards per cutter change)
TBM PREDICTOR MODEL ROCK DATA Uniaxial Compressive Strength (UCS) Brazilian (Indirect) Tensile Strength (BTS) Cerchar Abrasivity Index (CAI) Punch Penetration Index
UNIAXIAL COMPRESSIVE STRENGTH (ASTM D2938-95) Non-structural Failure Structural Failure BEFORE AFTER BEFORE AFTER
BRAZILIAN TENSILE STRENGTH (ASTM D3967-95) Normal Failure Structural Failure T Tensile Strength (psi) F Failure Load (lbs.) L Thickness of the disk (in.) D Diameter of the disk (in.) Effect of Foliation on Tensile Strength
PUNCH PENETRATION TEST
CERCHAR ABRASIVITY TEST Cerchar Abrasivity Index (CAI) has proven to be fairly accurate and is commonly used for cutter life estimation. A series of sharp 90 hardened pins of heat-treated alloy steel are pulled across a freshly broken surface of the rock. The average dimensions of the resultant wear flats are related directly to cutter life in field operation. The geometry of the planned excavation then allows calculation of the expected cutter costs per unit volume of material. 10 CAI 0.0254 d i 1 i
CERCHAR Abrasivity Index (CAI) for various rocks Quartzite 5.9 Norway Rock type CAI Location Shale 0.9 New York Shale 1.1 Ohio Limestone 1.1 Illinois Barea Sandstone 1.2 Ohio Indiana Limestone 1.3 Indiana Phyllite 1.3 Norway Mica Schist 2.2 Washington, D.C. Andesite 2.3 Arizona Quartz Diorite 3.2 Norway Red Sandstone 3.6 Kentucky Anphibolite 3.6 Norway Gabbro 3.7 Norway Granediorite 3.9 North Carolina Granite 4.0 Sweden Diorite 4.1 North Carolina Gneiss 4.1 Georgia Quartz Gneiss 4.3 Georgia Quartzite 4.3 East Africa Gneiss 4.4 Norway Sandstone 4.7 Kentucky Quartz Gneiss 4.8 Norway Granite Gneiss 4.8 Norway Mica Schist 5.3 New York
DISC CUTTER LIFE vs.cerchar INDEX
TBM MODEL ADJUSTMENT FACTORS Cutter wear Brittleness Petrographic features (suturing/interlocking) Foliation/bedding Porosity Joints/fissures
USES OF TBM PREDICTOR MODEL Develop estimates of TBM penetration rates Develop estimates of cutter life and costs Evaluate different TBM proposals Develop specs for ideal TBM for a project Evaluate different size cutters for ROP and life Optimize TBM performance
CAUSES OF REDUCED ROP AND/OR HIGHER CUTTER WEAR Rock is harder/tougher and/or more abrasive than anticipated Less and/or adverse jointing, bedding and foliation than anticipated Cutterhead design, cutter layout, stability, steering, vibration, etc. TBM operation at reduced capacity-lower cutter load Optimistic TBM performance estimates
WORLD TBM RECORDS - PERFORMANCE Indianapolis Deep Rock Tunnel ( 20.2 ft. diam., 7.6 mile long, limestone/dolomite) Be st day = 410 ft Be st week = 169 0 ft Be st Mont h = 5755 ft.
WORLD TBM RECORDS LONGEST TUNNEL Gotthard Base Tunnel, Switzerland
LIMMERN PUMP STORAGE TUNNEL 5.2 M. Hard Rock TBM 40 degree incline Double anti-reverse lock system
DELAWARE AQUEDUCT BYPASS TUNNEL
DELAWARE AQUEDUCT BYPASSTUNNEL Reach 1-2,560lf Sha le (Normanski ll For m at i on ) Reach 2-3,900lf Limestone & Do lo m i te (Wappi ng er Formati on ) Reach 3 3,500lf Limestone & Do lo m i te (Wappi ng er Formati on ) Reach 4 2,540lf Sha le (M ou nt Merin o Formati on )
Muck chute closure doors for controlling high water inflows
THANK YOU Levent Ozdemir