3. WHAT IS TUNNEL?
• Tunnel is an underground passageway
• Passageway dug through surrounding soil , earth or rock
• Enclosed structure expect at entrance & exit
• Note : Pipeline is not considered as tunnel
4. TYPES OF TUNNEL
• Traffic tunnels
• Hydropower tunnels
• Public utility tunnels
10. UNDERGROUND SURVEYING
• Survey operations
To be carried out beneath surface of the earth
• Used for
Tunneling
Exploration
Constr in subterranean passageways
• Peculiarities of underground surveying
Artificial Illumination reqd
Working space – cramped
For levelling instrument stations & benchmarks setting
Drill holes in rock reqd
Done by water dripping from the roof of passageways
11. SURVEY WORK IN TUNNELING
• Surface survey
• Transfer of underground alignment
• Levels in tunnels
SURFACE SURVEY TFR OF UNDERGROUND ALIGNMENT LEVELLING IN TUNNELS
12. LASER ALINGMENT
• Lasers installed in the tunnel
• Calibration to be carried out
• Generation of axis by laser spots
• Positioning of arches - as per str & soil condns
WKG OF TOTAL STATION
LASER ALIGNMENT TOTAL STATION
13. SOFTWARE FOR LASER SURVEY
• Talos – Motor laser system
• Software for tunnel proof hardware
• Uses basic surveying principles
• Talos – Used for stake out operations
Adjust supporting girders
Pipe umbrellas
Easy profile check
Data analysis
MOTOR LASER SYSTEM WKG PRINCIPLE TL - 80 LASER SYSTEM
15. ALINGMENT BY GPR
• Geodetic measurements reqd
• Tunnel heading control reqd
• Surveying is an imp factor
• Provide positioning & directional specifications
• Grnd Penetrating Radar is use for this purpose
GPR ALIGNMENT WKG PRINCIPLE OF GPR ALIGNMENT
16. TAUROS FOR ROADHEADERS
• Machine – based controlled guided system
• Maint spatial position & orientation
• Developed by Sandvik & Geodata
• Robust camera measurement units installed
• Used on both single shield TBMs as well as double shield TBMs
• Ensures automatic calculation of the best fitting ring
• Optimum ring sequencing can be achieved
• Time saving
• Reduce risk of damages to the shield
PARTS OF TAUROS
TAUROS
17. APPLICATIONS OF UNDERGROUND SURVEYS
• Constr of tunnels
• Constr of underground utilities
• Why tunnel is constructed ?
Open excavation becomes uneconomical when it is more than 20M
• Advantages
Reduces the grade
Shorten the distance
Meets the demand of - modern rapid transit in a city
Exact alignment
Proper gradient
Estb of permanent stations
Marking of proposed route
18. SURFACE SURVEY
• Connect points of each portal of
a tunnel
• Determination of azimuth
• Distance calculation
• Calculation of difference in
elevation
• Survey based on local suitable
coordinate system
• Note Survey is based on suitable
local coordinate
• Ref point prominent landmark
• Central line – MKG done
• Offset MKG along the tunnels
edge
ROBOTIC ALIGNMENT BY EDM
20. TRANSFER OF UNDERGROUND ALIGNMENT
• Excavation along the tunnel
alignment
• Insertion of shafts at intermediate
locations along the routes
• Vertical alignment done by -
Plumb bob
Optical collimator
Laser
LASER
OPTICAL COLLIMATOR
PLUMB BOB WKG PRINCIPLE
21. SHAFT FOR TUNNEL CONSTR
• Shaft is being used
• Shaft is made up of -
Steel tape
Chain
Construction rods
Steel wires
EDM
SHAFT PRINCIPLE USED
X-SEC DESIGN
23. ADVANTAGES OF TUNNELING
• Economical when the depth is beyond limit
• Limited disturbance for surface life & ground activities
• High speed construction
• Low power consumption
• Reduces noise pollution
• Freedom from snow & iceberg hazards in areas of high altitudes
• Restricted surface & air interference
• Easy gradients reduces hauling cost
• Greater protection in aerial warfare & bombing conditions.