Tunnel Lining Design and Construction

Transcription

1 Tunnel Lining Design and Construction Verya Nasri, PhD, PE 10 th Annual Breakthroughs in Tunneling Short Course August 15, 2017

2 Cast-in-Place Final Lining Design Considerations Strength Serviceability Durability Plain concrete versus reinforced concrete Fiber versus rebar Spray on concrete versus CIP concrete

3 Final Tunnel Linings Liner Geometry Construction Method Area of Application

4 Road Tunnels World Road Association (PIARC)

5 Rail Tunnels

6 Transit Tunnels

7 Subway Stations Mined Cut and Cover

8 Geometry Optimization

9 Ventilation

10 Station Cross Section

11 Caverns in Competent Rock

12 Permanent SOE Wall Munich

13 Underground Parking

14 Cut and Cover, Top-Down and Bottom-Up

15 Cut and Cover Tunnels

16 Immersed Tunnels

17 Final Tunnel Linings Liner Loading Structural Analysis Design

18 Structural Loading

19 Structural Loading p = RL p = RL p = RL p = 0 p = 0 p = 0 Uniform Rock Load b=d/2 45 º b=d/2 D D Unbalanced Rock Load

20 Groundwater Pressure Drained and Undrained Concepts WATER TABLE(HWL) CROWN OF ARCH.25Wcrown EFFECTIVE PRESSURE DISTRIBUTION.10Wbase HYDROSTATIC PRESSURE

21 Beam Spring Method US Army Corps of Engineers K r =E g /[R(1+v)] K t =0.5K r /(1+v)

22 2D Structural Analysis Cut & Cover Box Mined Cavern Beam-Spring Model

23 3D Structural Analysis Cut & Cover Box Mined Cavern Beam-Spring Model

24 Road Deck Central LRT Precast Unit In-situ Deck Construction in Parallel with Excavation & Lining Pavement

25 Double Deck Road

26 Stacked Subway

27 Design Pressure Envelopes for Braced Cuts (Peck, 1969)

28 Excavation Sequence, Support Installation and Flow Analysis

29 Convergence Confinement Method

30 Initial Ground Support Design Empirical Method (e.g. Q-System) Analytical Method (e.g. Key-Block) Numerical Method (Continuum and Discontinuum Modeling)

31 Continuum Analysis 2D modeling Hoek-Brown Failure Criterion 50 % Relaxation, Shotcrete Strength Varied With Excavation Sequence

32 Rock Mass Parameters Input - Intact Uniaxial Compressive Strength (UCS) - Intact Rock Modulus (Ei) - Disturbance Factor (D) - Geological Strength Index (GSI) - Intact Rock Parameter (mi) Output - Hoek-Brown Strength Parameters - Rockmass Deformation Modulus

33 Continuum Analysis Results No Yielding of Initial Support Small Ground Surface Deformations

34 Types of Discontinuities CONJUGATE JOINTS FOLIATION CLUSTER SUBVERTICAL STRUCTURE FAULT / SHEAR ZONE

35 Discontinuum Analysis Rock constitutive model: Mohr-Coulomb elastic/plastic failure Joint constitutive model: Barton-Bandis joint model

36 Discontinuum Analysis Results

37 3D Continuum Analysis

38 3D Continuum Analysis Results

39 3D Continuum Analysis Results

40 3D Discontinuum Analysis

41 3D Discontinuum Analysis Results

42 Seismic Design of Tunnel Final Lining Design & Analysis Approach Force Method for surface structures Deformation Method for underground structures Two-level seismic hazard (ODE and MDE)

43 Seismic Design of Tunnel Final Lining Deformation modes of tunnels due to seismic waves

44 Fire Design of Tunnel Final Lining

45 Reduction of Strength and Stiffness of Concrete

46 Final Lining Protection in Concrete Sewers Corrosion has been identified as No. 1 cause of deterioration in concrete sewers. Quantitative approach to assess the corrosion of the concrete final lining Measures to protect the concrete final lining

47 Life Expectancy of Concrete Final Lining The life expectancy of the concrete final lining: L = z / C L = service life, yr z = thickness of allowable loss (thickness covering the reinforcing steel), in. c = corrosion rate, in./yr

48 Liners and Coatings Example: Ameron T-Lock, a PVC sheeting that locks mechanically into the interior wall of concrete sewer pipes and tunnels

49 Sewers Subject to Low Corrosion Risk For a 100-year service life costly corrosion protection measures such as impermeable liners, coatings or polymer concrete are not warranted. Use calcareous aggregate and sacrificial concrete cover

50 Sewers Subject to High Corrosion Risk Recommendation: A combination of corrosion protection schemes including concrete with calcareous aggregates sacrificial concrete thickness protective lining Initial Liner CIP Liner Protective Liner

51 Waterproofing, Drained and Undrained Concepts

52 Waterproofing Details

53 Initial Liner Smoothness Criteria

54 Materials: Geotextile, Membrane, and Attachment Disk

55 Membrane Installation and Testing

56 Sectioning, Water Barrier, and Remedial Grout Pipes

57 Sprayed on Waterproofing Membrane Sprayed on membrane Elongation at rupture %100 Bond strength 1 MPa Tensile strength 2-4 MPa

58 New York City s Second Avenue Subway 72 nd Street Station and Tunnels Project Final Concrete Lining (Waterproofing and Concrete Stages)

59 72 nd Street Station and Tunnels Project Station Cavern Walls

60 72 nd Street Station and Tunnels Project Station Walls Forms & Rebar

61 72 nd Street Station and Tunnels Project Station Cavern Finished Walls

62 72 nd Street Station and Tunnels Project Station Arch Forming System

63 72 nd Street Station and Tunnels Project Station Arch Forming System

64 72 nd Street Station and Tunnels Project Station Arch Forming System

65 72 nd Street Station and Tunnels Project Tunnels Invert Concrete

66 72 nd Street Station and Tunnels Project Tunnels Arch Concrete

67 Final Tunnel Linings Architectural Aspects Magenta Station, Paris

68 Different Types of Structural and Architectural Concrete Light gray with satin finish for the entire structure Light gray with shiny finish for stair tunnels Light gray with rough finish for sidewalls of central cavern and side tunnels White only for columns and struts.

69 More than 10 mix designs were Used to answer the structural and architectural requirements Large scale samples for testing the formwork surface and its accessories

70 Completed Station

71 Metal (copper, aluminum ), exotic wood, concrete with multiple finishes (white, satin, shiny ), marble

72 Entrance

73 Entrance

74 Thank You