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10th Annual Breakthroughs in Tunneling Short Course, Chicago, IL

August 14-16, 2017

Low Pressure Tunnel Design

Jon KaneshiroPARSONS CORPORATION

Monday August 14: 4:15 to 4:40 PM

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Agenda:

Low Pressure Tunnel Design

1) Introduction

Definitions

Load Sharing

2) Case Histories Low Pressure Tunnel

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1) Introduction

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1) Introduction – Definitions

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1) IntroductionLoad sharing – Internal Water Pressure

Load Sharing is defined as sharing of the internal pressure in a water system between the ground and the liner. The pressure is transmitted from the liner to the ground through the annular backfill. The ability of the ground to handle these loads is determined by verification of rock modulus using in-situ testing, verifying sufficient ground cover, control of the annular backfill strength/stiffness, and proper liner design.

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Load Sharing Extent: 0 (lined) to 100% (unlined)

sh

sv

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2) Low Pressure Tunnels

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2) Low Pressure Segmented Lining Pressure Confinement Strategies

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2) Low Pressure Segmental Liner Case Histories

Preloading by External Grout pressure▪ DE, Keiser’s method, 1952Preloading by Jacks▪ DE, 1960, Dusseldorf sewage tunnel under Rhine, 14.8’ ODRebar steel▪ US, 1995-2000, South Bay Tunnel Outfall, San Diego, 12.5’ OD▪ JP, 1999-2009, Metropolitan Area Outer Underground Discharge

Channel, Tokyo, 17.7 to 34’? ODPost tensioning / Pre-stressing steel▪ FR, 1949, Subaqueous tunnel under Seine, 14’ & 16’ dia., steel bands▪ JP, ca. 1999-2003 (Osaka area)

▪ Onchigawa-Higashi Trunk Line, 9.7 ft OD, ▪ Yao-Hiraoka Trunk Line, 11.6 ft OD▪ Shitanoya Trunk Line, 9 ft OD▪ Midorigaoka Rainwater Trunk Line,10.2 ft OD

▪ CH, 2008, Thun Flood Relief Tunnel, 19.7’ OD

Water Leakage Criteria through micro cracks in concrete

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ACI 224 Control of Cracking in Concrete Structures limiting fs < 20 ksi

W = 0.10 fs (dc A)1/3 x 10-3

Where A = 2dcSdc = bar coverS = Bar SpacingW = 0.008 in. crack width for water retaining structures

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Kieser’s (1960) Method Prestressing segmented liner

As reported by Szechy (1966)

1. circumferential concrete bedding is placed, providing a smooth surface and grout barrier

2. grout fissures in rock and annular space

3. concrete segments erected4. 1-1/4” gap use low

pressure grouted until return in adjacent hole

5. finally pressure grouted to 150% of working load until cement suspension is hardened.

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Subaqueous Sewer Tunnel under Seine(Lalande, 1949)

As reported by Szechy (1966)

• 14 and 16 ft dia.• compressed air • hand excavation methods• 11” x 0.20” steel bands/grouted• segments 4’10” l, 1’10’ wd, 1’4” thk

1. two 50 ton jacks at two half rings

2. jacks tensioned and steel wedges installed to hold pretension

3. jacks removed and space filled with concrete

4. Joints clipped and band grouted5. Interior gunite layer

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Subaqueous sewage tunnel under RhineDusseldorf (Hochtief News, 1960)

As reported by Szechy (1966)• 14’8” OD• 2’3’ wide x 10’ thk segments• Prestressing keys at Qtr Arches

1. Prestressing bar tensioned against shoulders in joint with asbestos bearing pads

2. Joints filled with grout3. Followed by annular grout

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Continuous Hoop Re-barJoined by Bearing/Transfer Plates

San Diego’s SBOO Tunneled Outfall

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shap

Metropolitan Area Outer Discharge Channel, JP

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Hoop Re-bar fastened to C-shaped connectors which are in turn butted together and fastened with H-shape connectors at the segment Joint. (Miyao et al., 1999).

Continuous Hoop Re-bar

Fastened by C- and H- shape connectors

Continuous TendonsPost Tensioned/Prestressed

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Continuous TendonsP&PC Segment Lining Method

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Neyagawa Ryuiki sewerage Onji kawa Higashi Kannsenn (No 4 Kouku)

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View of Tunnel

Assembly situation of the B Segment X-Assembly situation of the K Segment Insertion of the unbounded PC Steel

Lap Direction, Jacking of Tendon Tension and Fixation Completion

Saitou et al., 1999

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Neyagawa Ryuiki sewerage Onji kawa Higashi Kannsenn (No 4 Kouku)

Photo-1. X-Anchor . Fixation Point Segment

Saitou et al., 1999

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Thun Flood Relief Tunnel, CH

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Haefilger, 2009; Kohler and Rupp, 2008

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Thun Flood Relief Tunnel, CH

Haefilger, 2009; Kohler and Rupp, 2008

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South Bay Tunnel Ocean Outfall (ca. 1995-2000)

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Hydrotest of Hoop Tendons or Bars (SBTO, ca. 1994)

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LACSD JWPCP Effluent Outfall Tunnel 2018-2024

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LACSD JWPCP Effluent Outfall Tunnel Proof Concept Test

Outside Face of Tunnel

Indicators numbering order:• Start at keystone• Clockwise (outside face)• Bottom to top ring

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1615

14 12 11 10 9

C

13

6 4 8

B

5

A

3 7 6

9

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1F1A1B 1E 1D 1C

1F1A1B1E 1D 1C

1F1A1B 1E 1D 1C

1F1A1B1E 1D 1C

A LVDT

1 Dial Indicator

LEDEND

1A Segment Type

Photo 1 Photo 2 Photo 1

Approx. Location of Stressing Pocket

Photo 3

LACSD JWPCP Effluent Outfall Tunnel, Proof of Concept Test

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Ring 1

Ring 2

Ring 3

Ring 4

Photo 2

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Conclusions

Issues and Conclusions Low Pressure One Pass Segmented Liner

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AlternativesTwo PassLoad SharingPlastic liner

Bearing TransferAnchorage/Liner thickness

Hoop BarsStrands

Steel vs. CarbonBonded vs. UnbondedAnchorage

Constructability

Example Trade Off Analysis

Alternative Description Relative

Reliability

Relative

Cost

Rank

1 Secondary grout,

lock in thrust

1 5 5

2 Hoop steel 2 4 8

3 Two-pass w/steel

or PCCP

5 1 5

4 Embedded plastic

linings

3 4 12

5 Steel shell 4 2 8

6 Pre-stressing

tendons

3 4 12

References Segmented Liners designed for low pressure

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• Haefliger, P., 2009, Thun Flood Relief Tunnel, Sept. 22 Presentation to D. Klug European Tunnel Tour.

• Hirosawa, N. et al., 2008, Development of composite concrete-packed steel segment, Nippon Steel Technical Report No. 97, January, 39–44.

• Kaneshiro, J.Y., S.J. Navin, and G.E. Korbin, 1996. Unique precast concrete segmented liner for the South Bay Ocean Outfall Project, In Ozdemir, L. (ed.), Proceedings of the International Conference on North American Tunneling, Washington, DC.

• Kohler, D. and B. Rupp, 2008, Thun flood relief tunnel, Part 1 – Challenges faced by the hydro-shield method., Tunnel, Vol. 7/

• Miyao, H et al., 1999. Development of a new lining for shield tunnels bearing internal pressures, ITA World Tunnel Congress Proceedings 1999, Oslo, Norway.

• Nishikawa, K, 2003, Development of a precast and prestressed concrete segmental lining, Tunnelling and Underground Space, V. 18.

• Saitou, S. , M. Kaneko, T. Sagara, M. Sugimoto, and J. Kondou, 1999, PC Segment Construction, Tunnel Engineering Thesis, Collection of Reports, Vol. 9. Translation from: Proceedings of Tunnel Engineering, Japan Society of Civil Engineers, Released on internet: June 27, 2011, https://www.jstage.jst.go.jp/article/journalte1991/9/0/9_0_325/_pdf

• Shield Tunneling Association of Japan, 2004. P&PC Segment Lining Method, www.shield-method.gr.jp/english/, accessed February 2012.

• Szechy, K., 1966, The Art of Tunnelling, Budapest.

▪ Hochtief Nachrichten (Newsletter), 1960, Rheintunnel Dusseldorf, Aug/Sept

▪ Keiser, A., 1960, Druckstollenbau (Pressure Tunnel Construction), Springer-Verlag

▪ Lalande, M., 1949, Diversite de applications du beton precontraint, Travaux, Feb.

▪ Rousselier, M., 1952, Le revetment des galeries, Annales de l’Institut Technique de B.T.P., V. 59

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Thank You!