Kiewit Approach for Tunnel Stabilization and Sewer Pipeline Replacement Project

Transcription

1 South Coast Water District Kiewit Approach for Tunnel Stabilization and Sewer Pipeline Replacement Project Board of Directors January 14-15, 2013

2 Overview of Construction Plan Highlights of Kiewit s Construction Approach 1. Worker Safety 2. No Spills Pipe Protection 3. Reduced Community Impacts 4. Proven Construction Methods 2

3 Mobilization, Sitework, Staging Aliso Creek Staging & Storage Area 0.46 Acre Project office Parking for craft and staff Equipment shop Material storage 4 th Avenue Site 0.27 Acre Primary access for tunnel operations Fencing and sound wall Paved site Electrical service Water treatment Site office 3

4 Construction Plan 4 4 ALISO CREEK STAGING AND STORAGE AREA

5 Mobilization, Site Work, Staging

6 4 th Avenue Shaft Construction Shaft Excavation and Support Total depth 93 vertical feet Finished diameter 20 feet Excavated in overburden and rock Permanent ground support installed Mitigation of surface settlement Precast concrete shaft cover 6

7 Soil Ground Support Grouted liner plate Steel ribs Rock Support Rock bolts Shotcrete Shaft excavation & support in overburden 22-ft dia. with liner plate and steel ribs (Euclid Creek Tunnel, OH) 7 7

8 Maintenance Bay Access Tunnel Access Shaft Tail Tunnel 8 8

9 Connector, Tail, Maintenance Tunnels Tail and Maintenance Tunnels Small Excavator, Loader Length 30 linear feet each Horseshoe,10 feet Tail tunnel for material handling Maintenance tunnel used for equipment service Connector Tunnel Roadheader Length 320 linear feet Horseshoe, 10 feet Roadheader excavation All Excavations Fiber-reinforced shotcrete lining 9

10 Transition Tunnel Construction Small Excavator, Loader Fiber-reinforced shotcrete lining Protection of sewer pipe, transition to existing tunnel Benefits 100% protection at all times Two stage protection plan Completed ahead of any construction activities First: Place concrete pipe protection Second: Excavate existing tunnel transition 10

11 11 Pipe Protection

12 12 Concrete Encasement

13 Tunnel Enlargement & Stabilization South Heading Construction Challenges Low cover area Adit 16A/B Sand backfill sections North Heading Construction Challenges Laguna Lido Laguna Royale 13

14 14 Geotechnical Conditions

15 Tunnel Enlargement Lining Types 15 15

16 16 Tunnel Enlargment Liner Type 1

17 17 Tunnel Enlargment Liner Type 2

18 18 Tunnel Enlargment Liner Type 3

19 19 Tunnel Enlargment Liner Type 4

20 20 Tunnel Enlargment Liner Type 5

21 21 Tunnel Enlargement Means & Methods Pipe Protection 150-ft Section, flotation restraint, pumped concrete Excavation by Roadheader Muck removal by Loader Installation of Ground Support as prescribed Shotcrete fiber reinforced wet mix Steel Sets / Lattice Girders installed by round length Spiling pre support drilled in advance Ventilation through Adits

22 Tunnel Enlargement - Equipment Tunnel Equipment: 25-Ton Roadheader 1 per Heading 2.3 CY Tunnel Loader 1-2 per Heading Electric Shotcrete/Concrete Pump 1 per Heading 22 Surface Support Equipment: 55-Ton Hydraulic Crane 1 Each 3 CY Front End Loader 1 Each 175 HP Ventilation Fan 1 per Heading

23 Roadheader Excavation 25 Ton Weight Construction Equipment Class (Los Alamos Tunnel, NM) Tunnel Equipment 23 23

24 Tunnel Material Handling Tunnel loader Spoils removal Material and supplies handling Flexibility and efficiency Manage curves and grades 24

25 Tunnel Equipment Roadheader in Tunnel Loader in Tunnel 25

26 27 Portal 2 - Staging

27 28 Portal 4 - Staging

28 29 Adit 16A/B Construction Plan

29 30 Laterals

30 31 Custom Pipe Placing Gantry

31 Construction Schedule Activity NTP Mobilize & Sitework 4 th Ave. Shaft Connector Tunnel Tunnel South Tunnel North Laterals Low Cover Area Portal 2 Tunnel Portal 4 Tunnel Invert & Pipe Final Completion 32 North South

32 Benefits of Kiewit Approach Permanent shaft construction concurrent with excavation Detailed plan for tunnel transition section Liner types appropriate for variable ground conditions Minimize beach landings for low cover areas Reduced construction staging area at Portals 2 and 4 Efficient approach for placement of new sewer pipe 33

33 Cost Proposal Summary Direct Costs Mobilization & Demobilization $3,500,000 Mobilization $ 3,400,000 Demobilize $ 100,000 4 Th Ave Shaft & Connector Tunnel $ 1,628, Mobilization $ 110,000 Shaft Excavation and Lining $ 723,000 Shaft Base Chambers $ 120,000 Connector Tunnel $ 590,000 Spoil Disposal, Care of Water, Cleanup $ 85,000

34 Cost Proposal Summary Direct Costs Portal 2 & Tunnel Stabilization $ 1,567,000 Mobilization $ 176,000 Demolition, Care of Water, Relocate Laterals $ 233,000 Bulkhead & Backfill, Enlarge and Line Tunnel $ 1,099,000 Spoil Disposal and Site Restoration $ 59,000 Portal 4 $ 346, Mobilize, Relocate Public Facilities, Fence Work Area $ 100,000 Demolish Structure & Excavation, Care of Water $ 123,000 New Portal Structure $ 85,000 Site Restoration & Demobilize $ 38,000

35 Cost Proposal Summary Direct Costs Adits 16A & 16B $ 150,000 Construct Artificial Tunnel Between Adits $ 150,000 Tunnel Stabilization Shaft Access $29,961, Tunnel Enlargement and Liner $ 24,507,000 Pipe Protection & Concrete Invert $ 1,846,000 Special Care Intervals $ 2,435,000 Rehabilitate & Abandon Adits $ 625,000 Spoil Disposal & Care of Water $ 533,000 Provisional Ground Support $ 15,000

36 Cost Proposal Summary Direct Costs Pipeline Replacement $ 2,170,000 Install 24-Inch Pipeline $ 1,850,000 Permanent Lateral Connections $ 250,000 Connect 24-Inch Pipeline $ 70,000 Insurance $ 3,175,000 Composite Rate Plus Builder s Risk $ 3, 175,000 37

37 Cost Proposal Summary Direct Costs General Costs Field Indirects $18,450,000 Construction Management $ 8,400,000 As-built Drawings $ 50,000 General Work Items $ 10,000,000 38

38 Cost Proposal Summary Direct Costs Mobilization & Demobilization $ 3,500,000 4 Th Ave Shaft & Connector Tunnel $ 1,628,000 Portal 2 & Tunnel Stabilization $ 1,567,000 Portal 4 $ 346,000 Adits 16A & 16B $ 150,000 Tunnel Stabilization Shaft Access $29,961,000 Pipeline Replacement $ 2,170,000 General Costs (Field Indirects) $ 18,450,000 Insurance $ 3,175,000 Total Direct Costs $60,947,000 39

39 Cost Proposal Summary Direct Costs $ 60,947,000 Indirect Costs (Home Office) $ 4,686,215 Target Profit $ 12,750,000 Target Price $78,383,215 40

40 41 Thank You