1. ANCIT WORKSHOP Torino, 30-31 March 1998 NO-DIG(Trenchless method) Technologies in Reducing Information Infrastructure Costs and Creating New Construction Forms NTT Access Network Systems Laboratories Minoru Tanaka

2. ANCIT WORKSHOP Torino, 30-31 March 1998 500 400 300 200 100 0 (1,000km) (%) 100 80 60 40 20 0 ‘52‘56‘60‘64‘68‘72‘76‘80‘84‘88‘92 Total conduit length Installation ratio High growth period Fig.1 Transition in City Water Conduit Construction

3. ANCIT WORKSHOP Torino, 30-31 March 1998

4. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.3 Nighttime Construction Conditions (Opencut method)

5. ANCIT WORKSHOP Torino, 30-31 March 1998 (1,000km) 16 14 12 10 8 6 4 2 0 1400 1200 1000 800 600 400 200 0 (km) ‘77‘79‘81‘83‘85‘87‘89‘91‘93‘95 Fig.4 Transition in Sewage Conduit Construction Length and NO-DIG Process Length

6. ANCIT WORKSHOP Torino, 30-31 March 1998 NTT building Free-space conduit Cable tunnelDistribution conduit Existing conduit Fig.5 NTT Infrastructure Network System Configuration

7. ANCIT WORKSHOP Torino, 30-31 March 1998 Yearly Cumulative 80 60 40 20 0 (km) 0 100 200 300 400 ‘88‘89‘90‘91‘92‘93‘94‘95‘96 Fig.6 Transition in NTT NO-DIG Process Length

8. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.7 ACEMOLE Lineup Driving distance Short distance (up to 100m)Long distance (up to 300m) PC10PL30 DC15 DL35 DL50 Applicable Soil Condition Driving Method Penetrating Nonmuck- Discharge Excavating Muck- Discharge Soft- Normal soil Hard and gravely soil N-Value< Approx.15 N-Value< Approx.50 *Pebbles *Rocks *The DL supports soil containing pebbles and rocks.

9. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.8 Position Detecting System Driving machine Pressure sensor Hose Transmitting coil Search coil Standard pressure sensorSilicon tank Measurement equipment (Electromagnetic Induction method) (Liquid Pressure Difference Method) Planned route Electromagnetic field

10. ANCIT WORKSHOP Torino, 30-31 March 1998

11. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.10 Shallow Seismic Reflection Exploration System *Development of a compact mechanical seismic source *Development of a device that moves all geophones together Exploration condition Change in the soil stratum Seismic source Geophones Ground Surface -10m Seismic wave Shallow seismic reflection exploration range

12. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.11 Remote Operation Support System Operation center Cockpit Driving conditions Ground conditions Driving control Driving database server CockpitExecution site Facility information Survey Information Driving information Driving Know-how Optimum driving Control Feedback PHS Network Execution sites (Cyber Control System)

13. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.12 Total NO-DIG System SurveysDesignConstruction Design support system ACCESSMOLE (for distribution routes) ACEMOLE (for main routes) Seismic exploration system Soil investigation Ground penetrating radar Buried pipes investigationNO-DIG DesignNO-DIG construction Designing easily by using artificial intelligence(AI) functions and databases

14. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.13 Expansion system NTT group System development Access Network Systems Laboratories Support Training Training center Design Training Technology transfer Guidance and support Surveys and design Subsidiaries and branch offices(designers) Construction ordering Construction(operators) Construction companies(domestic) Construction(operators) Construction companies(overseas) Rental and consulting services Group enterprises Overseas expansion Group enterprises Machine sales Technical guidance Machine rentals Technical guidance ACEMOLE Association

15. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.14 Progress of All NO-DIG operations Invention periodExpansion periodAll NO-DIG operations 1987199820002005 Introduction of ACEMOLE Introduction of Future ACEMOLE Evolution of NO-DIG operations Microtunneling Opencut NO-DIG (85%) (15%) With Future ACEMOLE With current technology (%) 100 50 0 100 50 0 Designated cities Provincial cities Opencut methodNO-DIG of Future ACEMOLE With the introduction Cost Reduction

16. ANCIT WORKSHOP Torino, 30-31 March 1998 Fig.15 Future ACEMOLE High speed pit Remote support operation Unit components High-speed driving through hard soil Auto navigation High accuracy continuous position detection construction Themes Cost reduction Automation All NO-DIG Civil technology innovation Combination with leading-edge telecommunication technology High speed driving Compact pits Automated operation operations Automatic pipe connection