Creating Value Delivering Solutions Rehabilitation of Existing River Piers for Dick Henderson Bridge, West Virginia i i Joe Carte, P.E. W.V. Department of Transportation Scott Zang, P.E. Michael Baker Jr., Inc.
Project Location location West Virginia Charleston 3
Project Location I-64 Bridges Dick Henderson Bridge Charleston 4
Nitro Project Location St. Albans 5
Existing Bridge Nitro Built 1934, Rehabbed 1977 12 Ton Weight Limit St. Albans 6
Existing Bridge 20 ADT 17000 (2007) Functionally Obsolete Sufficiency rating 42.5 out of 100 7
Proposed bridge 8
Why reuse the piers? 9
Nitro Residential Residential School Fields Marina/ docks Car Dealer St. Albans 10
Schedule Reusing existing piers shortens the time the bridge is out of service BRIDGE CLOSED 11
Permitting Permitting for new piers not required 12
Span Length and Grade Required grade to clear extended opening Existing Opening = 450 x60 Possible Required Opening for New Bridge = 600 x 70 13
Condition of Existing Main Piers Sound except at very top In Depth Inspection 14
Condition of Existing Main Piers 15
Subsurface Conditions 600 Very thin soil (0-3 ) Clay 550 Silty Sand Soft Claystone 500 Sandy Shale 16
Soft Claystone Sandy Shale 17
Evaluation of Existing Spread Footing B (ft) q R Strength Limit State φ =045 0.45 (KSF) q R Extreme Limit State φ =10 1.0 (KSF) 45 4.5-59.6 7 27.7 61.5 10 28.88 64.0 18 31.4 69.8 18
Evaluation of Existing Spread Footing F x Extreme II Barge Impact F x = 1377 kips 40.4 V V = 6758 kips e = 82ft 8.2 ft. B = 2.1 ft. 18.5 σ = 74.4 ksf 74.44 ksf >596ksf 59.6 19
Micropile Concept Construction Sequence 1. Install cofferdam 20
Micropile Concept Construction Sequence 2. Install micropiles 21
Micropile Concept Construction Sequence 3. Place tremie seal 22
Micropile Concept Construction Sequence 4. Dewater cofferdam 23
Micropile Concept Construction Sequence 5. Cast new footing 24
Micropile Concept Construction Sequence 6. Cast stem encasement 25
Micropile Concept 12 clear to new footing 10 ¼ Hole 9 5/8 OD x 0.5 wall N80 pipe 5000 psi grout 2 x #18 Gr 75 10 Casing embedment 28 Bond zone q r = 526 kips 26
3 Months less closure time Improve Existing Pier Time Savings? None overall Vs. Reduced superstructure cost Cost Savings? None for pier Demolish and Build New Pier 27
Construction 28
Contractor s Proposed Pile Construction ti Method 1. Place drilling deck with 14 guide pp pipes 29
Contractor s Proposed Pile Construction ti Method 2. Install temporary 11 pipe pp into competent rock or top of existing footing 30
Contractor s Proposed Pile Construction ti Method 3. Drill 10.25 hole to final tip elevation 31
Contractor s Proposed Pile Construction ti Method 4. Lower permanent 9.625 N80 casing and center reinforcing bar to bottom of hole NOTE: permanent casing is coupled to reinforcing bar with custom bracket that suspends it at the proper height ht in the hole 32
Contractor s Proposed Pile Construction ti Method 5. Lower grout standpipe over top of permanent casing. NOTE: Grout standpipe seals to top of permanent casing with a rubber compression seal and is held down by drill rig 33
Contractor s Proposed Pile Construction ti Method 6. Insert grout tremie tube to bottom of pile 7. Place grout till return is observed in outside pipe 34
Contractor s Proposed Pile Construction ti Method 8. Remove tremie tube 9. Install pressure cap and pressurize till grout returns or 100 psi 35
Contractor s Proposed Pile Construction ti Method 10. Remove standpipe 11. Remove e temporary casing pipe 36
Pre-Production Load Tests Clay Silty Sand Soft Claystone Sandy Shale 37
Test Pile Installation 38
Test Setup 39
St. Albans - Results Dis splacem ment (in n) 0 0.2 0.4 0.6 0.8 1 1.2 14 1.4 Load (kips) 0 200 400 600 800 Top of Pile Elastic Compression Approx. Max. bond stress mobilized = 62.1 psi 40
Drilling Piles 41
Installing Reinforcing and Casing 42
Tremie Grouting Grout Return 43
Grout Return Grout Pressurization 44
Encapsulation Dowels 45
Excess Grout Cleanout by Divers 46
Dewatering Cofferdam 47
Dewatered Cofferdam 48
Dowel Holes and Piles 49
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Creating Value Delivering Solutions Questions? Joe Carte, P.E. W.V. Department of Transportation Scott Zang, P.E. Michael Baker Jr., Inc.