EL VALOR DE INNOVACION EN TUNELES

Transcription

1 EL VALOR DE INNOVACION EN TUNELES NOVIEMBRE 2008 Harald Wagner, PhD, PE D2 Consult Ltda.,Linz/Austria ITA EXCO Experto Especial

2 CONTENT 1. Preface / Introduction 2. Role of Ground Investigations 3. Role of the Designer 4. Base of Geotechnical Design 5. Geomechanic Aspects 6. Innovative Design in Conventional Tunnelling 7. Technological Progress in Monitoring 8. Innovative Design in TBM Tunnelling 9. Technological Progress in TBM Segment Design 10. Innovations in Contracting Practices 11. Selfperforming Construction 12. Risk Management Practices 13. Innovative Cost Aspects 2

3 1. INTRODUCTION Underground works are featured by of geology, geometry and purpose. uniqueness The decision for optimum construction method requires competence and integrity. The engineer in charge is challenged to think about innovative means and methods. 3

4 2. ROLE OF GROUND INVESTIGATION Results of geological and geotechnical investigations, and innovative interpretation of results Description of the Rock Mass Types and the associated key parameters Description of the Rock Mass Behaviour Types, the relevant influencing factors, the analyses performed, and the innovative geotechnical model A report on the determination of excavation and support, relevant scenarios considered and analyses applied. 4

5 GROUND INVESTIGATIONS The basis for the Austrian approach to tunnel site investigation is a geotechnical rock mass characterisation procedure, which aims to correlate rock mass properties with rock mass behaviour through rock and project specific key parameters during the early design. During later design stages rock mass models are developed and updated. 5

6 The designer has to include 3. ROLE OF DESIGNER In detailed design all structures and incorporate latest project developments, results of additional site investigations and requirements by the authority. An update of geotechnical investigations, support measures, distribution of support classes, details of auxiliary construction methods and provision of information as required by the national standards and guidelines. 6

7 4. BASE OF GEOTECHNICAL DESIGN Step 1: Determination of Rock Mass Types Step 2: Determination of Rock Mass Behavior Types Step 3: Determination of the excavation and support Step 4: Geotechnical report-baseline construction plan Step 5: Determination of excavation classes 7

8 INNOVATION BECOMING STANDARD 8

9 INNOVATION BECOMING STANDARD CROWN BENCH INVERT 9

10 SAFETY MANAGEMENT WARNING STEPS / ACTION LEVEL Geomechanic Planning Conventional Tunnelling 10

11 5. GEOMECHANIC ASPECTS Question 1 Question 2 How to define safety of tunnel lining during and after construction? 11

12 GEOMECHANIC ASPECTS Equilibrium Safety Safety 12

13 6. CONVENTIONAL TUNNELLING TECHNOLOGY Tunnel BEG Lot H5 (Austria 2003) 13

14 INNOVATIVE INITIAL LINING Lit.: Conventional Tunnelling Austrian Society for Geomechanics - Daft

15 INNOVATIVE INITIAL LINING Lit.: Conventional Tunnelling Austrian Society for Geomechanics - Daft

16 INNOVATIVE NATM DESIGN Carretera Bogota Villavicencio Tunnel 6A 16

17 INNOVATIVE FINAL LINING Carretera Bogota Villavicencio 17

18 7. PROGRESS IN MONITORING 18

19 ADVANCED MONITORING SCHEME 19

20 MONITORING FAULT ZONE 20

21 8. INNOVATIVE SEGMENT TECHNOLOGY LINING JOINT CONNECTORS SEALING SEGMENT- PRODUCTION DOWELS CONVENTIONAL GASKETS INSTALLATION GUIDING RODS INTEGRATED GASKETS 21

22 TBM - SHIELD PARAMETERS TUNNEL PROJECT DATA LENGTH, DIAMETER, RADIUS, GEOLOGY HYDROLOGY, CONSTRUCTION TIME TUNNEL FACE TUNNEL LINING EXCAVATION PRE INVESTI- -GATION STABILITY QUALITY 22

23 INNOVATIVE TBM DESIGN Carretera Bogota Villavicencio Tunnel 6A 23

24 TBM DESIGN CHARACTERISTICS Thickness depends on size of bending moment Width depends on space in rear of TBM Ring division depends on thruster jacks Segment form depends on designer s experience Ring erector design depends on segment weight 24

25 QUALITY CONTROL Tolerances of segment Tolerances of moulds Concrete mixture Compressive strength Concrete cover Surface of concrete 25

26 INNOVATIVE TBM TUNNEL INTERSECTIONS Lay-by niche and cross passage 26

27 INNOVATIVE DOUBLE DECK TUNNEL Cross Section / Safety Chamber (Paris, France) 27

28 INNOVATIVE DOUBLE LANE TUNNEL Cross Section / Longitudinal Section (Paris, France) 28

29 RIVER CROSSING TUNNELS Changjiang Tunnel, Wuhan/China (Opening December 2008) 29

30 9. INNOVATION IN JOINT DESIGN 30

31 INNOVATION IN SEGMENT KINEMATICS 31

32 INNOVATION IN SEGMENT KINEMATICS 32

33 10. CONVENTIONAL CONTRACT PRACTICE A typical feature of Austrian Tunnelling is its tradition of good cooperation between the parties to a contract. The cooperation model is generally of benefit to all parties involved, calling for technical competence and positive willingness to compromise, also called partnering. 33

34 APPROVED INNOVATION During tunnel driving immediate and joint decisions by the partners to a contract must be possible within predetermined limits to respond to changing rock mass behaviour. Tunnelling works in Austria are executed on the basis of unit price contracts. 34

35 11. SELFPERFORMING CONSTRUCTION Projects with low competition may result in selfperforming construction of the client providing all personnel, equipment and material. The technical risk of construction is on the client side (without any profit). The economic risk of low competetion e.g.bidding of only two contractors, can such be controlled. 35

36 12. RISK INTRODUCTION Risk is the ultimate factor, deciding upon success or failure of a project. Risk needs to be covered and needs to be managed to finalize a project successfully. Risk needs to be shared between the parties involved. 36

37 SHORT RISK EVALUATION OF TECHNOLOGY NATM and TBM have been fundamentally differing competing technologies Interaction between excavation and geomechanical response is differing New findings of interactive risk behaviour between soils, rock and water 37

38 SEGMENT INSTALLATION RISK Decisive installation parameters Influences of rotation and migration Influences of TBM advance pressure Twisted thrust shoes and rigid erector hydraulics Transport conditions and segment design Sequence of installation Shield drive and eccentricity of thrusters Sectional tension forces Crack appearance Quality assurance programs 38

39 FLOW CHART DESIGN RISK Identify Hazards (H) Forms Complete Hazard Identification and Risk Assessment Form (MIRA) Check no further Risk can be eliminated Complete Design Decision Form (DDF) Identifay Residual Hazards Revise DDF with Residual Risk Advice Client Complete Risk Register Issue to Contractor 39

40 FLOW CHART CONSTRUCTION RISK Proceed with Construction Identify Hazards during Construction (H) Forms Complete Hazard Identification and Risk Assessment Proceed with Construction Revise CDF with Residual Risk Complete Risk Register Proceed with Construction 40

41 TBM TUNNELLING TECHNOLOGY WSKE-TBM (Vienna 2004) 41

42 TBM TUNNELLING TECHNOLOGY WSKE-TBM (Vienna 2005) 42

43 RISK MANAGEMENT METHODOLOGY Establish objectives and risk appetite Risk identification, classification and allocation Assessment, impact and quantification Identify mitigation procedures Prepare or update risk register 43

44 RISK REDUCING MEASURES The Basis is formed by project descriptions, drawings, technical specifications, etc. The main layout needs to be evaluated Sufficient safety measures, e.g. fire protection, emergency escape routes have to be foreseen 44

45 13. COST ASPECTS Issues of quality, cost and schedule relate to Construction Geotechnical Design Geological Risk Risk Management Partnering 45

46 CONVENTIONAL TUNNELLING TECHNOLOGY RANGE OF RISK Typical Cost Distribution Conventional Tunnelling 46

47 TBM TUNNELLING TECHNOLOGY RANGE OF RISK Typical Cost Distribution Mechanized Tunnelling 47

48 TBM COST DISTRIBUTION Carretera Bogota Villavicencio Tunnel 6A Tunnel Linning Site Installation TBM - Equipment Energy & Spare Parts General Equipment Tunnel Supply Personal Underground Supply Personal Surface Personal Construction Management Tunnel Overhead Tunnel Linning Site Installation TBM - Equipment Energy & Spare Parts General Equipment Tunnel Supply Personal Underground Supply Personal Surface Personal Construction Management Tunnel Overhead 48

49 SUMMARY Innovations in Tunnelling relate to construction technologies (NATM / TBM), contract practices and are driven by quality and economics. Conventional Tunnelling is progressing in terms of initial linings (support/monitoring) and final linings (including operation and maintenance). Mechanized Tunnelling is progressing in terms of TBM and lining improvements for universal geologic conditions. 49