1
Driven Pile Foundation Driven Pile Foundation Support-Cost ComponentsSupport-Cost Components
Wagner Komurka Geotechnical Group, Inc.
2009 PDCA Professors’ Driven Pile Institute2009 PDCA Professors’ Driven Pile Institute
June 15-16, 2009June 15-16, 2009
Van E. Komurka, P.E.Van E. Komurka, P.E.
2
• Discuss support-cost components:Discuss support-cost components:– PilePile• ConventionalConventional• Profile (as a function of depth)Profile (as a function of depth)
– CapCap– Column (matching allowable pile loads to Column (matching allowable pile loads to
structure column loads)structure column loads)– SystemSystem
Talk OutlineTalk Outline• Define support cost.Define support cost.
• Present case histories (large and small) illustrating load-matching Present case histories (large and small) illustrating load-matching approach.approach.
3
The cost of an installed or constructed The cost of an installed or constructed foundation element or system divided by foundation element or system divided by its allowable load, usually expressed in its allowable load, usually expressed in dollars per ton (i.e., how many dollars it dollars per ton (i.e., how many dollars it costs to support one ton of load).costs to support one ton of load).
Sup•portSup•port'' Cost (S Cost (Sŭŭ•pōrt•pōrt'' Kŏst) Kŏst)
4
• As a normalized parameter, allows direct As a normalized parameter, allows direct (apples-to-apples) economic comparison (apples-to-apples) economic comparison of different foundation alternatives:of different foundation alternatives:– Shallow vs. deep (e.g., spread footings vs. piles)Shallow vs. deep (e.g., spread footings vs. piles)– Deep vs. deep (e.g., drilled piers vs. piles)Deep vs. deep (e.g., drilled piers vs. piles)– Pile section vs. pile section (e.g., 10.75” vs. 12.75”)Pile section vs. pile section (e.g., 10.75” vs. 12.75”)– Pile capacity vs. pile capacity (e.g., 70Pile capacity vs. pile capacity (e.g., 70TT vs. 150 vs. 150TT))
Sup•portSup•port'' Cost (S Cost (Sŭŭ•pōrt•pōrt'' Kŏst) Kŏst)
• Allows economic evaluation and Allows economic evaluation and optimization of deep foundation system optimization of deep foundation system cost componentscost components
5
CapCap
PilesPiles
Design Column Design Column LoadLoad
ColumnColumn
Deep Foundation Deep Foundation System System ComponentsComponents
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Pile Support Pile Support CostCost
Pile CostPile Cost
Allowable Pile Allowable Pile LoadLoad
In general, higher allowable pile In general, higher allowable pile loads result in lower pile loads result in lower pile support costs:support costs:• Spread pile length invested to Spread pile length invested to penetrate through poor soils penetrate through poor soils over more capacityover more capacity•In competent soils, capacity In competent soils, capacity generally increases faster with generally increases faster with depth than does costdepth than does cost
=
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Pile Support CostPile Support Cost
Pile Support Cost Pile Support Cost ==
Pile CostPile Cost
Allowable Pile LoadAllowable Pile Load
$1,500 per $1,500 per pilepile
50-ton allow. 50-ton allow. loadload
= $30 / ton= $30 / ton $3,000 per $3,000 per pilepile
150-ton allow. 150-ton allow. loadload
= $20 / ton= $20 / ton
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WKGWKG22 Pile Support Costs Pile Support Costs
Project Name Pile TypeAllowable Pile
Load, tons
Pile Support Cost, dollars per
allowable ton
Midwest Express (Wisconsin) Center, Phase 1 10.75 x 0.36512.75 x 0.365
100150
12.1211.52
Miller Park 16-inch Monotube 200 12.20
Johnson Controls Brengel Technology Center 12.75 x 0.312 148 13.48
Potawatomi Casino ExpansionPotawatomi Casino Parking Structure
10.75 x 0.25010.75 x 0.250
8083
Overall Project Average 15.55
Milwaukee Journal-Sentinel Production Facility 10.75 x 0.307
4065758085
20.5916.9715.1215.3414.81
Overall Project Average 15.64
Sixth Street Viaduct Replacement10.75 x 0.25012.75 x 0.37512.75 x 0.37512.75 x 0.375
65154182190
20.4710.508.62
13.92
Overall Project Average 15.28
State Fair Park Exposition Hall 9.625 x 0.545 200 9.40
Great Lakes Aquatarium/Discovery World Museum(Pier Wisconsin)
10.75 x 0.36513.375 x 0.48013.375 x 0.480
91180251
14.7313.369.91
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y = 90.662x-0.402
R2 = 0.712
8
10
12
14
16
18
20
22
40 60 80 100 120 140 160 180 200 220 240 260
Pile Support Costs – WKGPile Support Costs – WKG22 Projects ProjectsP
ile S
up
port
Cost,
dollars
per
allow
ab
le
Pile S
up
port
Cost,
dollars
per
allow
ab
le
ton
ton
Allowable Pile Load, tons (factor of safety = 2.0)Allowable Pile Load, tons (factor of safety = 2.0)
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Pile Support Costs – Sixth Street Pile Support Costs – Sixth Street Viaduct ReplacementViaduct Replacement
y = 245.41x-0.5529
R2 = 0.4787
y = 35.326e-0.0058x
R2 = 0.5423
5
10
15
20
25
30
35
40
40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190
Allowable Pile Load, tonsAllowable Pile Load, tons
Pile S
up
port
Cost,
dollars
per
Pile S
up
port
Cost,
dollars
per
allow
ab
le t
on
allow
ab
le t
on
Various: Pile Diameters (10.75- and 12.75-inch- O.D.) Safety Factor (from 2.0 to 2.5) Installation Criteria (WEAP, Modified EN) Subsurface Conditions (from till at 4 feet, to 60 feet of organic silt)
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Achieving Higher-Capacity PilesAchieving Higher-Capacity Piles
Use larger section, larger hammer, drive Use larger section, larger hammer, drive piles “harder,” perhaps deeper.piles “harder,” perhaps deeper.
Increase design stresses (e.g., from 9-12 ksi to Increase design stresses (e.g., from 9-12 ksi to 16 ksi)16 ksi)
Incorporate soil/pile set-up:Incorporate soil/pile set-up: Use displacement pile.Use displacement pile. Adjust testing program (wait longer to test, Adjust testing program (wait longer to test,
restrike testing, etc.).restrike testing, etc.).
Use higher-strength concrete (e.g., in Use higher-strength concrete (e.g., in concrete-filled pipe piles from 3-4 ksi to 6 ksi)concrete-filled pipe piles from 3-4 ksi to 6 ksi)
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Cap Support Cap Support CostCost
Cap CostCap Cost
Design Column Design Column LoadLoad
Higher allowable pile loads Higher allowable pile loads result in fewer piles, smaller result in fewer piles, smaller caps, and therefore lower caps, and therefore lower cap support costs.cap support costs.
Minimized cap support cost Minimized cap support cost results from using the results from using the minimum required number minimum required number of piles.of piles.
=
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Cap Support CostsCap Support CostsC
ap
Su
pp
ort
Cost,
dollars
per
allow
ab
le
Cap
Su
pp
ort
Cost,
dollars
per
allow
ab
le
ton
ton
Design Column Load, kipsDesign Column Load, kips
2
3
4
5
6
7
8
9
10
11
12
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000
50-Ton Piles
75-Ton Piles
100-Ton Piles
250-Ton Piles
150-Ton Piles200-Ton Piles
3-Pile Minimum
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Column Support Column Support CostCost
Pile Cap Cost + Pile Cap Cost + ΣΣ Pile Costs Pile Costs
Design Column Design Column LoadLoad
Measures how well the Measures how well the allowable pile load, in allowable pile load, in conjunction with the minimum conjunction with the minimum required number of piles, required number of piles, matches the design column matches the design column load.load.
Minimum column support cost Minimum column support cost results from using the optimum results from using the optimum allowable pile load.allowable pile load.
=
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Optimum Allowable Pile Optimum Allowable Pile LoadLoad
Design Column LoadDesign Column Load
Minimum Req’d No. of Minimum Req’d No. of PilesPiles
Design Column Load = 900 kipsDesign Column Load = 900 kips
Minimum Req’d No. of Piles = 3Minimum Req’d No. of Piles = 3
Optimum Allowable Pile Load = Optimum Allowable Pile Load =
900 kips900 kips
3 piles3 piles
= 300 kips/pile = 150 tons/pile= 300 kips/pile = 150 tons/pile
900K
=
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Lower-Than-Optimum Allowable Pile Lower-Than-Optimum Allowable Pile LoadsLoads
Increased pile support costs – each ton of Increased pile support costs – each ton of allowable pile load costs more than it would allowable pile load costs more than it would have with higher-capacity piles.have with higher-capacity piles.
Increased cap support costs – each cap is Increased cap support costs – each cap is larger than it would have been with higher-larger than it would have been with higher-capacity piles.capacity piles. Increased column support costs – for a given Increased column support costs – for a given column load, pile and cap costs are higher column load, pile and cap costs are higher than they would have been with higher-than they would have been with higher-capacity (closer to optimum allowable load) capacity (closer to optimum allowable load) piles.piles. Increased number of pile installations – may Increased number of pile installations – may increase total project drive time.increase total project drive time.
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Higher-Than-Optimum Allowable Higher-Than-Optimum Allowable LoadsLoads
Increased column support costs – although Increased column support costs – although pile support costs are low, and cap costs are pile support costs are low, and cap costs are minimized, unnecessary capacity is installed minimized, unnecessary capacity is installed (unnecessary cost is incurred).(unnecessary cost is incurred).
Low unit cost. All you need.
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Match Allowable Pile Loads to Column Match Allowable Pile Loads to Column Loads!Loads!
Piles are below-grade structural extensions Piles are below-grade structural extensions of above-grade structural elements; their of above-grade structural elements; their design should be integrated with the above-design should be integrated with the above-grade design.grade design. Using one allowable pile load for a project is Using one allowable pile load for a project is analogous to using one beam or column analogous to using one beam or column design throughout a building.design throughout a building.
Two fixed design components:Two fixed design components: Structural loads to support (column load Structural loads to support (column load
schedule).schedule). Soil/pile resistance behavior to support Soil/pile resistance behavior to support
structural loads (depth vs. capacity structural loads (depth vs. capacity relationships).relationships).
Deep foundation system design flexibility Deep foundation system design flexibility (choice of pile type, section, allowable load, (choice of pile type, section, allowable load, safety factor, etc.) allows accommodating safety factor, etc.) allows accommodating fixed design components.fixed design components.
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System Support System Support CostCost
ΣΣ Deep Foundation System Deep Foundation System CostsCostsΣΣ Column Design Loads Column Design Loads
Measures overall cost-Measures overall cost-effectiveness of deep effectiveness of deep foundation system. Provides foundation system. Provides basis for comparison of basis for comparison of viable design and installation viable design and installation options.options.
=
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Load-Matching Design ApproachLoad-Matching Design Approach
Obtain foundation layout, column load Obtain foundation layout, column load schedule, and the minimum required schedule, and the minimum required number of piles at each cap, from structural number of piles at each cap, from structural engineer.engineer. Calculate optimum allowable pile load for Calculate optimum allowable pile load for each cap.each cap.
If desired, calculate required “ultimate” pile If desired, calculate required “ultimate” pile capacity for each cap. To evaluate the cost-capacity for each cap. To evaluate the cost-effectiveness of field testing, this can be effectiveness of field testing, this can be done for a range of factors of safety.done for a range of factors of safety.
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22
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F.S. = 2.00Maximum
Optimum RequiredAllowable "Ultimate"
Column Min. Column Pile PileLine No. Load, Load, Capacity,
Designation of Piles kips tons tons
0.A-8.5 1 158 79 1580.A-0.5 1 180 90 180
P-3.3 1 181 91 181P-3.7 1 181 91 181P-4.5 1 181 91 181P-5 1 181 91 181
P-5.5 1 181 91 181P-6 1 181 91 181
0.A-8 1 203 102 203M.5-8 1 228 114 228
N-8.5 1 360 180 360P.7-8.5 1 360 180 360P-0.5 1 360 180 360P-8.5 1 360 180 360Q.8-3 1 360 180 360Q-0.5 1 360 180 360M.5-4 1 368 184 368J -5 2 748 187 374
G-7 3 1479 247 493H-7 3 1479 247 493K-6 3 1484 247 495B-7 3 1487 248 496B-6 3 1507 251 502C-8 3 1508 251 503
R1-5.9 3 1510 252 503K-7 3 1529 255 510
C-4 3 1874 312 625F-6 3 1879 313 626J -6 3 1942 324 647J -4 3 1995 333 665Q-9 3 2003 334 668R-9 3 2003 334 668
448
Pier Pier WisconsinWisconsin
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Load-Matching Design ApproachLoad-Matching Design Approach
Obtain foundation layout, column load Obtain foundation layout, column load schedule, and an indication of the minimum schedule, and an indication of the minimum required number of piles at each cap, from required number of piles at each cap, from structural engineer.structural engineer. Calculate optimum allowable pile load for Calculate optimum allowable pile load for each cap.each cap.
Calculate required “ultimate” pile capacity Calculate required “ultimate” pile capacity for each cap. To evaluate the cost-for each cap. To evaluate the cost-effectiveness of field testing, this can be effectiveness of field testing, this can be done for a range of factors of safety.done for a range of factors of safety.
Generate histogram of optimized allowable Generate histogram of optimized allowable pile loads (or of “ultimate” pile capacities).pile loads (or of “ultimate” pile capacities).
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194
tons
91 to
ns
180
tons
227
tons
0
10
20
30
40
50
60
70
75 100 125 150 175 200 225 250 275 300 325 350 375
Allowable Pile Load HistogramAllowable Pile Load HistogramPier WisconsinPier Wisconsin
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Piles
Piles
Allowable Pile Load, tonsAllowable Pile Load, tons
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Load-Matching Design ApproachLoad-Matching Design Approach
Obtain foundation layout, column load Obtain foundation layout, column load schedule, and an indication of the minimum schedule, and an indication of the minimum required number of piles at each cap, from required number of piles at each cap, from structural engineer.structural engineer. Calculate optimum allowable pile load for Calculate optimum allowable pile load for each cap.each cap.
Calculate required ultimate pile capacity for Calculate required ultimate pile capacity for each cap. To evaluate the cost-effectiveness each cap. To evaluate the cost-effectiveness of field testing, this can be done for a range of field testing, this can be done for a range of factors of safety.of factors of safety. Generate histogram of optimized allowable, Generate histogram of optimized allowable, and/or ultimate, pile capacities.and/or ultimate, pile capacities.
Select appropriate allowable pile loads (or Select appropriate allowable pile loads (or “ultimate” pile capacities), with design-“ultimate” pile capacities), with design-team input.team input.
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194
tons
91 to
ns
180
tons
227
tons
0
10
20
30
40
50
60
70
75 100 125 150 175 200 225 250 275 300 325 350 375
Allowable Pile Load HistogramAllowable Pile Load HistogramPier WisconsinPier Wisconsin
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Piles
Piles
Allowable Pile Load, tonsAllowable Pile Load, tons
180 tons
251 tons
91 tons
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Load-Matching Design Approach Load-Matching Design Approach (continued)(continued)
Select viable pile type(s) and section(s) for Select viable pile type(s) and section(s) for selected allowable loads/capacities (91selected allowable loads/capacities (91TT, 180, 180TT, , and 251and 251TT) ) {borings}{borings}..
Estimate individual pile lengths required for Estimate individual pile lengths required for selected pile capacities.selected pile capacities.
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-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
0 100 200 300 400 500 600 700
Estimated Ultimate Pile Capacity - Estimated Ultimate Pile Capacity - BoringsBorings
13.375-inch-diameter Pipe Piles13.375-inch-diameter Pipe Piles
Pile T
oe E
levati
on
, fe
et
Pile T
oe E
levati
on
, fe
et
Estimated “Ultimate” Pile Capacity, tonsEstimated “Ultimate” Pile Capacity, tons
30
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
0 50 100 150 200 250 300 350Estimated “Ultimate” Capacity, tonsEstimated “Ultimate” Capacity, tons
Pile T
oe E
levati
on
, fe
et
Pile T
oe E
levati
on
, fe
et Pile Test Pile Test
Program Program Capacity Capacity ProfileProfileLong-
term Capacity
EOID Capacity
Set-Up
31
Load-Matching Design Approach Load-Matching Design Approach (continued)(continued)
Select viable pile type and section for Select viable pile type and section for selected pile capacities.selected pile capacities.
Estimate individual pile lengths required for Estimate individual pile lengths required for selected pile capacities.selected pile capacities.
Estimate total pile lengths required for Estimate total pile lengths required for project.project.
Using representative prices, estimate total Using representative prices, estimate total pile cost for project.pile cost for project.
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Allowable Pile Load HistogramAllowable Pile Load HistogramPier WisconsinPier Wisconsin
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Allowable Pile Load, tonsAllowable Pile Load, tons
227
tons
180
tons
91 to
ns
194
tons
0
10
20
30
40
50
60
70
75 100 125 150 175 200 225 250 275 300 325 350 375
180 tons
251 tons
91 tons
33
F.S. = 2.00Maximum
Optimum RequiredAllowable "Ultimate"
Column Min. Column Pile Pile Est. Pile Est. Pile(s) Est. Pile(s)Line No. Load, Load, Capacity, No. Length, Footage, Cost,
Designation of Piles kips tons tons of Piles feet feet dollars
0.A-8.5 1 158 79 158 1 62 62 1,3400.A-0.5 1 180 90 180 1 62 62 1,340
P-3.3 1 181 91 181 1 62 62 1,340 91-ton max. P-3.7 1 181 91 181 1 62 62 1,340 allow. load:P-4.5 1 181 91 181 1 62 62 1,340 71P-5 1 181 91 181 1 62 62 1,340 10.75x0.365
P-5.5 1 181 91 181 1 62 62 1,340 feet:P-6 1 181 91 181 1 62 62 1,340 4,402
0.A-8 1 203 102 203 1 86 86 2,405M.5-8 1 228 114 228 1 86 86 2,405
N-8.5 1 360 180 360 1 86 86 2,405 180-ton max.P.7-8.5 1 360 180 360 1 86 86 2,405 allow. load:P-0.5 1 360 180 360 1 86 86 2,405 108P-8.5 1 360 180 360 1 86 86 2,405 13-3/8" 0.480Q.8-3 1 360 180 360 1 86 86 2,405 feet:Q-0.5 1 360 180 360 1 86 86 2,405 9,288M.5-4 1 368 184 368 1 95 95 2,657J -5 2 748 187 374 2 95 190 5,314
G-7 3 1479 247 493 3 95 285 7,971 251-ton max. H-7 3 1479 247 493 3 95 285 7,971 allow. load:K-6 3 1484 247 495 3 95 285 7,971 177B-7 3 1487 248 496 3 95 285 7,971 13-3/8" 0.480B-6 3 1507 251 502 3 95 285 7,971 feet:C-8 3 1508 251 503 3 95 285 7,971 16,815
R1-5.9 3 1510 252 503 4 95 380 10,629K-7 3 1529 255 510 4 95 380 10,629
C-4 3 1874 312 625 4 95 380 10,629 251-ton max.F-6 3 1879 313 626 4 95 380 10,629 allow. load:J -6 3 1942 324 647 4 95 380 10,629 125J -4 3 1995 333 665 4 95 380 10,629 13-3/8" 0.480Q-9 3 2003 334 668 4 95 380 10,629 feet:R-9 3 2003 334 668 4 95 380 10,629 11,875
448 481 42,380 $1,157,416
3 Capacities (91, 180, and 251 tons)
$21.61 / ft
$27.97 / ft
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Load-Matching Design Approach Load-Matching Design Approach (continued)(continued)
Select viable pile type and section for Select viable pile type and section for selected pile capacities.selected pile capacities.
Estimate individual pile lengths required for Estimate individual pile lengths required for selected pile capacities.selected pile capacities.
Calculate total pile lengths required for Calculate total pile lengths required for project.project.
Calculate total pile cost for project.Calculate total pile cost for project.
Perform additional iterations as desired.Perform additional iterations as desired.
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F.S. = 2.00Maximum
Optimum RequiredAllowable "Ultimate"
Column Min. Column Pile Pile Est. Pile Est. Pile(s) Est. Pile(s) Est. Pile Est. Pile(s) Est. Pile(s)Line No. Load, Load, Capacity, No. Length, Footage, Cost, Number Length, Footage, Cost,
Designation of Piles kips tons tons of Piles feet feet dollars of Piles feet feet dollars
0.A-8.5 1 158 79 158 1 62 62 1,340 2 58 116 2,2230.A-0.5 1 180 90 180 1 62 62 1,340 2 58 116 2,223
P-3.3 1 181 91 181 1 62 62 1,340 91-ton max. 2 58 116 2,223P-3.7 1 181 91 181 1 62 62 1,340 allow. load: 2 58 116 2,223P-4.5 1 181 91 181 1 62 62 1,340 71 2 58 116 2,223P-5 1 181 91 181 1 62 62 1,340 10.75x0.365 2 58 116 2,223
P-5.5 1 181 91 181 1 62 62 1,340 feet: 2 58 116 2,223P-6 1 181 91 181 1 62 62 1,340 4,402 2 58 116 2,223
0.A-8 1 203 102 203 1 86 86 2,405 2 58 116 2,223M.5-8 1 228 114 228 1 86 86 2,405 2 58 116 2,223
N-8.5 1 360 180 360 1 86 86 2,405 180-ton max. 3 58 174 3,334P.7-8.5 1 360 180 360 1 86 86 2,405 allow. load: 3 58 174 3,334P-0.5 1 360 180 360 1 86 86 2,405 108 3 58 174 3,334P-8.5 1 360 180 360 1 86 86 2,405 13-3/8" 0.480 3 58 174 3,334Q.8-3 1 360 180 360 1 86 86 2,405 feet: 3 58 174 3,334Q-0.5 1 360 180 360 1 86 86 2,405 9,288 3 58 174 3,334M.5-4 1 368 184 368 1 95 95 2,657 3 58 174 3,334J -5 2 748 187 374 2 95 190 5,314 6 58 348 6,668
G-7 3 1479 247 493 3 95 285 7,971 251-ton max. 12 58 696 13,335H-7 3 1479 247 493 3 95 285 7,971 allow. load: 12 58 696 13,335K-6 3 1484 247 495 3 95 285 7,971 177 12 58 696 13,335B-7 3 1487 248 496 3 95 285 7,971 13-3/8" 0.480 12 58 696 13,335B-6 3 1507 251 502 3 95 285 7,971 feet: 12 58 696 13,335C-8 3 1508 251 503 3 95 285 7,971 16,815 12 58 696 13,335
R1-5.9 3 1510 252 503 4 95 380 10,629 12 58 696 13,335K-7 3 1529 255 510 4 95 380 10,629 13 58 754 14,447
C-4 3 1874 312 625 4 95 380 10,629 251-ton max. 15 58 870 16,669F-6 3 1879 313 626 4 95 380 10,629 allow. load: 15 58 870 16,669J -6 3 1942 324 647 4 95 380 10,629 125 16 58 928 17,780J -4 3 1995 333 665 4 95 380 10,629 13-3/8" 0.480 16 58 928 17,780Q-9 3 2003 334 668 4 95 380 10,629 feet: 16 58 928 17,780R-9 3 2003 334 668 4 95 380 10,629 11,875 16 58 928 17,780
448 481 42,380 $1,157,416 1,560 90,480 $1,733,597
$576,181
3 Capacities (91, 180, and 251 tons) 1 Capacity (10.75 x 0.188, 63 tons)
$19.16 / ft
$21.61 / ft
$27.97 / ft
36
F.S. = 2.00Maximum
Optimum RequiredAllowable "Ultimate"
Column Min. Column Pile Pile Est. Pile Est. Pile(s) Est. Pile(s) Est. Pile Est. Pile(s) Est. Pile(s)Line No. Load, Load, Capacity, No. Length, Footage, Cost, Number Length, Footage, Cost,
Designation of Piles kips tons tons of Piles feet feet dollars of Piles feet feet dollars
0.A-8.5 1 158 79 158 1 62 62 1,340 2 58 116 2,2230.A-0.5 1 180 90 180 1 62 62 1,340 2 58 116 2,223
P-3.3 1 181 91 181 1 62 62 1,340 91-ton max. 2 58 116 2,223P-3.7 1 181 91 181 1 62 62 1,340 allow. load: 2 58 116 2,223P-4.5 1 181 91 181 1 62 62 1,340 71 2 58 116 2,223P-5 1 181 91 181 1 62 62 1,340 10.75x0.365 2 58 116 2,223
P-5.5 1 181 91 181 1 62 62 1,340 feet: 2 58 116 2,223P-6 1 181 91 181 1 62 62 1,340 4,402 2 58 116 2,223
0.A-8 1 203 102 203 1 86 86 2,405 2 58 116 2,223M.5-8 1 228 114 228 1 86 86 2,405 2 58 116 2,223
N-8.5 1 360 180 360 1 86 86 2,405 180-ton max. 3 58 174 3,334P.7-8.5 1 360 180 360 1 86 86 2,405 allow. load: 3 58 174 3,334P-0.5 1 360 180 360 1 86 86 2,405 108 3 58 174 3,334P-8.5 1 360 180 360 1 86 86 2,405 13-3/8" 0.480 3 58 174 3,334Q.8-3 1 360 180 360 1 86 86 2,405 feet: 3 58 174 3,334Q-0.5 1 360 180 360 1 86 86 2,405 9,288 3 58 174 3,334M.5-4 1 368 184 368 1 95 95 2,657 3 58 174 3,334J -5 2 748 187 374 2 95 190 5,314 6 58 348 6,668
G-7 3 1479 247 493 3 95 285 7,971 251-ton max. 12 58 696 13,335H-7 3 1479 247 493 3 95 285 7,971 allow. load: 12 58 696 13,335K-6 3 1484 247 495 3 95 285 7,971 177 12 58 696 13,335B-7 3 1487 248 496 3 95 285 7,971 13-3/8" 0.480 12 58 696 13,335B-6 3 1507 251 502 3 95 285 7,971 feet: 12 58 696 13,335C-8 3 1508 251 503 3 95 285 7,971 16,815 12 58 696 13,335
R1-5.9 3 1510 252 503 4 95 380 10,629 12 58 696 13,335K-7 3 1529 255 510 4 95 380 10,629 13 58 754 14,447
C-4 3 1874 312 625 4 95 380 10,629 251-ton max. 15 58 870 16,669F-6 3 1879 313 626 4 95 380 10,629 allow. load: 15 58 870 16,669J -6 3 1942 324 647 4 95 380 10,629 125 16 58 928 17,780J -4 3 1995 333 665 4 95 380 10,629 13-3/8" 0.480 16 58 928 17,780Q-9 3 2003 334 668 4 95 380 10,629 feet: 16 58 928 17,780R-9 3 2003 334 668 4 95 380 10,629 11,875 16 58 928 17,780
448 481 42,380 $1,157,416 1,560 90,480 $1,733,597
$576,181
3 Capacities (91, 180, and 251 tons) 1 Capacity (10.75 x 0.188, 63 tons)
$19.16 / ft
$21.61 / ft
$27.97 / ft
37
Pile Support Costs – WKGPile Support Costs – WKG22 Projects ProjectsP
ile S
up
port
Cost,
dollars
per
allow
ab
le
Pile S
up
port
Cost,
dollars
per
allow
ab
le
ton
ton
Allowable Pile Load, tons (safety factor = 2.0)Allowable Pile Load, tons (safety factor = 2.0)
y = 90.662x-0.402
R2 = 0.712
8
10
12
14
16
18
20
22
40 60 80 100 120 140 160 180 200 220 240 260
38
First Place CondominiumsFirst Place Condominiums
Relatively small project, approximately 200 Relatively small project, approximately 200 piles required.piles required.
Renovation of a former storage warehouse Renovation of a former storage warehouse into condominiums.into condominiums.
Piles required only beneath small building Piles required only beneath small building addition.addition.
Existing geotechnical engineering report Existing geotechnical engineering report prepared for different site development prepared for different site development plans.plans.
A review of existing recommendations A review of existing recommendations relative to currently proposed development relative to currently proposed development was desired.was desired.
39
21
5
50
36
12
5
42
10
8
12
9
54
72
0
5
10
15
20
25
30
30 50 70 90 110 130 150 170 190 210
Op
tim
um
(M
inim
um
) R
eq
uir
ed
Nu
mb
er
of
Op
tim
um
(M
inim
um
) R
eq
uir
ed
Nu
mb
er
of
Piles
Piles
Allowable Pile Load, tonsAllowable Pile Load, tons
Optimum Allowable Pile Load Optimum Allowable Pile Load HistogramHistogram
First Place CondominiumsFirst Place Condominiums
40
First Place Condominiums - Proposed First Place Condominiums - Proposed DesignsDesigns
AllowableAllowable NumberNumber EstimatedEstimated
DesignDesign Load, tonsLoad, tons of Pilesof Piles FootageFootage
OriginalOriginal 7070 205205 15,58015,580
41
21
5
50
36
12
5
42
10
8
12
9
54
72
0
5
10
15
20
25
30
30 50 70 90 110 130 150 170 190 210
Op
tim
um
(M
inim
um
) R
eq
uir
ed
Nu
mb
er
of
Op
tim
um
(M
inim
um
) R
eq
uir
ed
Nu
mb
er
of
Piles
Piles
Allowable Pile Load, tonsAllowable Pile Load, tons
Optimum Allowable Pile Load Optimum Allowable Pile Load HistogramHistogram
First Place CondominiumsFirst Place Condominiums
42
First Place Condominiums - Proposed First Place Condominiums - Proposed DesignsDesigns
AllowableAllowable NumberNumber EstimatedEstimated
DesignDesign Load, tonsLoad, tons of Pilesof Piles FootageFootage
OriginalOriginal 7070 205205 15,58015,580
RevisedRevised 7272 180180 14,04014,040
SAVE:SAVE: 2525 1,5401,540
$34,250 + cap costs$34,250 + cap costs
on $346,500 worth of pileson $346,500 worth of piles
43
First Place Condominiums - Proposed First Place Condominiums - Proposed DesignsDesigns
AllowableAllowable NumberNumber EstimatedEstimated
DesignDesign Load, tonsLoad, tons of Pilesof Piles FootageFootage
OriginalOriginal 7070 205205 15,58015,580
RevisedRevised 7272 180180 14,04014,040
Alternate Alternate 100100 130130 $60,000 $60,000 savingssavings
72 tons per pile x 180 piles = 12,960 tons to 72 tons per pile x 180 piles = 12,960 tons to supportsupport
12,960 tons / 100 tons per pile = 130 piles12,960 tons / 100 tons per pile = 130 piles
Save 50 piles & $60,000 ?Save 50 piles & $60,000 ?
44
21
5
50
36
12
5
42
10
8
12
9
54
72
0
5
10
15
20
25
30
30 50 70 90 110 130 150 170 190 210
Op
tim
um
(M
inim
um
) R
eq
uir
ed
Nu
mb
er
of
Op
tim
um
(M
inim
um
) R
eq
uir
ed
Nu
mb
er
of
Piles
Piles
Allowable Pile Load, tonsAllowable Pile Load, tons
Optimum Allowable Pile Load Optimum Allowable Pile Load HistogramHistogram
First Place CondominiumsFirst Place Condominiums
45
72-ton 72-ton allowaballowab
lele
100-ton 100-ton allowaballowab
lele
72 tons 72 tons 72 tons
100 tons
100 tons
100 tons
46
First Place Condominiums - Proposed First Place Condominiums - Proposed DesignsDesigns
AllowableAllowable NumberNumber EstimatedEstimated
DesignDesign Load, tonsLoad, tons of Pilesof Piles FootageFootage
OriginalOriginal 7070 205205 15,58015,580
RevisedRevised 7272 180180 14,04014,040
AlternateAlternate 100100 164164 15,74415,744
SAVE:SAVE: 16 (not 50)16 (not 50) -1,704-1,704
($37,897)($37,897) (if same pile section is used) (if same pile section is used)
47
ConclusionsConclusions• Consider using higher-capacity piles Consider using higher-capacity piles
(when building loads warrant)(when building loads warrant)- Lower pile support costLower pile support cost- Lower cap support costLower cap support cost
• Consider matching (optimizing) Consider matching (optimizing) allowable pile loads to column loadsallowable pile loads to column loads- Lower column support costLower column support cost
• All should result in more-cost-All should result in more-cost-effective driven pile foundationseffective driven pile foundations
• Evaluate design options/alternatives Evaluate design options/alternatives using actual column loads and allowable using actual column loads and allowable pile load histogrampile load histogram
48
Questions / Comments?Questions / Comments?