Nget Pyaw Taw Bridge (150'-0" span)

At Nget Pyaw Taw Village, Kawa Township, Bago Region

October 2017
 Nget Pyaw Taw Bridge (150'-0" span)
At Nget Pyaw Taw Village, Kawa Township, Bago Region

(A) Pile Foundation for Abutment Wall

24" φ Bored Pile Capacity

Material Capacity
Concrete strength, fc' = 3000 psi
Rebar strength,fy = 50000 psi
Concrete Area,Ag = 491.328 in2
Rebar Area, As (9-T25mm) = 7.611 in2
Pile capacity , Q = 0.33Agfc' + 0.5Asfy
Pile capacity , Q = 677 kips
Pile capacity , Q = 302 Tons

Geotechnical Capacity (See attached)

Friction resistance, Qs = 39.40 kips
Bearing resistance, Qb = 287.38 kips
Total resistance, Q = 326.78 kips
= 146 Tons (Control)
From Etabs Result,
Input
Dead Load includes all self weight of members
AASHTO Standards, HS 20-44, Live Load = 480 psf)
Output
Abutment Wall Loading = 447 Tons

By providing 6 nos of 24" φ bored piles

Total bored pile capacity, Q = 875 Tons
Total bored pile capacity = 875 Tons > Abutment wall loading = 447 Tons

(B) Pile Foundation for Piers

32" φ Bored Pile Capacity

Material Capacity
Concrete strength, fc' = 3000 psi
Rebar strength,fy = 50000 psi
Concrete Area,Ag = 873.472 in2
Rebar Area, As (12-T25mm) = 9.134 in2
Pile capacity , Q = 0.33Agfc' + 0.5Asfy
Pile capacity , Q = 1093 kips
Pile capacity , Q = 488 Tons

Geotechnical Capacity (See attached)

Friction resistance, Qs = 70.04 kips
Bearing resistance, Qb = 376.13 kips
Total resistance, Q = 446.17 kips
= 199 Tons (Control)
From Etabs Result,
Input
Dead Load includes all self weight of members
AASHTO Standards, HS 20-44, Live Load = 480 psf)
Output
Pier Loading = 236 Tons

By providing 2 nos of 32" φ bored piles

Total bored pile capacity, Q = 398 Tons
Total bored pile capacity = 398 Tons > Abutment wall loading = 236 Tons

From Etabs Result,

Required Steel area for Pier = 7.069 in2
Used steel area (12- T25mm) = 9.134 in2
Used steel area > Required steel area ( OK )
BORED PILE CAPACITY

BORE HOLE NO.(1)

Pile size = 24 in Ø Ab = π/4(242) = 3.14 ft2 Perimeter, pD= 6.28 ft WT = 3 ft

Depth PileLength Thickness Pile

Soil Description γ γ' C CU φ б б' бvo ' SPT,N Nq Nc Qb kip δ tan δ α ΣQs
(ft ) (ft ) z capacity

Brown silty SAND

10 0 2 124.31 61.91 0.00 0.00 22.0 248.62 123.8 61.9 3 9.25 20.36 1.80 17.6 0.318 0.85 0.08 1.88
trace Clay,trace Gravel

Brown silty CLAY &

12 2 6 124.81 62.41 183.00 91.5 8.0 997.48 498.3 311.1 3 2.21 8.61 2.48 6.4 0.112 0.85 3.01 5.5
SAND

Gray silty SAND

18 8 6 122.26 59.86 0.00 91.5 23.0 1731.04 857.4 677.9 4 10.30 21.84 21.93 18.4 0.334 0.85 6.40 28.3
trace Clay

Gray sandy silty CLAY

24 14 6 125.03 62.63 139.00 69.5 7.0 2481.22 1233.22 1045.3 2 2.00 8.16 1.78 5.6 0.098 0.85 8.63 10.4
trace Gravel

Gray sandy silty CLAY

30 20 10 125.03 125.03 139.00 139.0 7.0 3731.52 2483.52 1858.4 3 2.00 8.16 3.56 5.6 0.098 0.85 16.05 19.6
trace Gravel

Reddish yellowish gray

40 30 10 124.90 62.50 570.00 354.5 8.0 4980.52 3108.52 2796.0 8 2.21 8.61 9.59 6.4 0.112 0.85 34.97 44.6
sandy silty CLAY

Brown gray SAND

50 40 10 122.84 60.44 0.00 285.0 28 6208.92 3712.92 3410.7 9 17.96 31.80 192.46 22.4 0.413 0.85 65.34 257.8
some silt, trace Clay

Brown gray SAND

60 50 10 122.84 60.44 0.00 0.0 28 7437.32 4317.32 4015.1 15 17.96 31.80 226.57 22.4 0.413 0.85 100.64 327.2
some silt, trace Clay

Gray silty CLAY

70 60 10 117.74 55.34 364.00 182.0 5 8614.72 4870.72 4594.0 4 1.64 7.34 4.20 4 0.070 0.85 110.36 114.6
trace Sand

Gray silty CLAY

80 70 10 117.74 55.34 364.00 364.0 5 9792.12 5424.12 5147.4 4 1.64 7.34 8.40 4 0.070 0.85 129.79 138.2
trace Sand

Gray silty CLAY

90 80 10 122.70 60.30 924.00 644.0 6 11019.12 6027.12 5725.6 15 1.82 7.74 15.65 4.8 0.084 0.85 164.16 179.8
trace Sand

Brownish gray silty CLAY

100 90 10 124.21 61.81 1529.00 1226.5 7 12261.22 6645.22 6336.2 23 2.00 8.16 31.44 5.6 0.098 0.85 229.63 261.1
same Sand

Brownish gray silty CLAY

110 100 10 124.21 61.81 1529.00 1529.0 7 13503.32 7263.32 6954.3 2.00 8.16 39.19 5.6 0.098 0.85 311.25 350.4
same Sand 25
γ = Unit weight ofSoil (lb/ft3)
бv0' = (б1'+б2')/2
γ' = Effective unit weight of soil (lb/ft3)
Nc,Nq = Bearing capacity factor
δ = 0.8φ
φ Qb = Nc Cu Ab Qb = Nq бv0' Ab ( in sand )
C = Undisturbed undrained cohesion (lb/ft2)

CU = Average undisturbed undrained cohesion (lb/ft ) 2

α = Adhesion factor Qs = α Cu As ( in clay ) Qs = Ks бv0' tan δ As ( in sand )

φ = Angle of friction(degree) Qb = Bearing resistance (Kip)

2 Qs = Shaft resistance (Kip)

б = Overburden pressure at pile base(lb/ft )
PILE CAPACITY

BORE HOLE NO.(2)

Pile size = 24 in Ø Ab = π/4(242) = 3.14 ft2 Perimeter, pD= 6.28 ft WT = 3 ft

Depth PileLength Thickness Pile

Soil Description γ γ' C CU φ б б' бvo ' SPT,N Nq Nc Qb kip δ tan δ α ΣQs
(ft ) (ft ) z capacity

Brown gray clayey

10 0 2 120.05 57.65 153.00 153.00 6.0 240.10 115.3 57.7 2 1.82 7.74 3.72 4.8 0.084 0.85 4.90 8.62
sandy SILT

Brown gray clayey

12 2 6 120.05 57.65 153.00 153.0 6.0 960.40 461.2 288.3 2 1.82 7.74 3.72 4.8 0.084 0.85 9.80 13.5
sandy SILT

Brown gray clayey

18 8 6 120.05 57.65 153.00 153.0 6.0 1680.70 807.1 634.2 2 1.82 7.74 3.62 4.8 0.084 0.85 10.61 14.2
sandy SILT

Brown gray clayey

24 14 6 120.05 57.65 153.00 153.0 6.0 2401.00 1153.00 980.1 2 1.82 7.74 3.72 4.8 0.084 0.85 15.51 19.2
sandy SILT

Brown gray clayey

30 20 10 120.05 120.05 153.00 153.0 6.0 3601.50 2353.50 1753.3 2 1.82 7.74 3.72 4.8 0.084 0.85 23.67 27.4
sandy SILT

Gray silty CLAY

40 30 10 120.65 58.25 421.00 287.0 6.0 4808.00 2936.00 2644.8 5 1.82 7.74 6.98 4.8 0.084 0.85 38.99 46.0
some Sand

Gray silty SAND

50 40 10 121.95 59.55 0.00 210.5 25 6027.50 3531.50 3233.8 8 12.81 25.26 130.19 20 0.365 0.85 23.35 153.5
trace Clay

Yellownish gray sandy silty

60 50 10 125.80 63.40 644.00 322.0 7 7285.50 4165.50 3848.5 9 2.00 8.16 24.24 5.6 0.098 0.85 31.45 55.7
CLAY trace Grave

Yellownish gray sandy silty

70 60 10 125.80 63.40 644.00 644.0 7 8543.50 4799.50 4482.5 7 2.00 8.16 16.51 5.6 0.098 0.85 65.83 82.3
CLAY trace Grave

Gray CLAY & SILT

80 70 10 121.92 59.52 770.00 707.0 6 9762.70 5394.70 5097.1 9 1.82 7.74 17.18 4.8 0.084 0.85 103.57 120.8
trace Sand, trace Gravel

Brownish light gray

90 80 10 124.91 62.51 753.00 761.5 8 11011.80 6019.80 5707.3 14 2.21 8.61 20.60 6.4 0.112 0.85 144.22 164.8
silty sandy CLAY

Brownish gray silty CLAY

100 90 10 127.78 65.38 1537.00 1145.0 7 12289.60 6673.60 6346.7 24 2.00 8.16 29.35 5.6 0.098 0.85 205.34 234.7
Trace Sand

Brownish gray silty CLAY

110 100 10 127.78 65.38 1537.00 1537.0 7 13567.40 7327.40 7000.5 25 2.00 8.16 39.40 5.6 0.098 0.85 287.38 326.8
Trace Sand
γ = Unit weight ofSoil (lb/ft3)
бv0' = (б1'+б2')/2
γ' = Effective unit weight of soil (lb/ft3)
Nc,Nq = Bearing capacity factor
δ = 0.8φ
φ Qb = Nc Cu Ab Qb = Nq бv0' Ab ( in sand )
C = Undisturbed undrained cohesion (lb/ft2)

CU = Average undisturbed undrained cohesion (lb/ft ) 2

α = Adhesion factor Qs = α Cu As ( in clay ) Qs = Ks бv0' tan δ As ( in sand )

φ = Angle of friction(degree) Qb = Bearing resistance (Kip)

2 Qs = Shaft resistance (Kip)

б = Overburden pressure at pile base(lb/ft )
PILE CAPACITY

BORE HOLE NO.(1)

Pile size = 32 in Ø Ab = π/4(322) = 5.59 ft2 Perimeter, pD= 8.37 ft WT = 3 ft

Depth PileLength Thickness Pile

Soil Description γ γ' C CU φ б б' бvo ' SPT,N Nq Nc Qb kip δ tan δ α ΣQs
(ft ) (ft ) z capacity

Gray silty SAND

20 0 4 122.26 59.86 0.00 0.0 23.0 489.04 239.4 119.7 4 10.30 21.84 6.89 18.4 0.334 0.85 0.84 7.7
trace Clay

Gray sandy silty CLAY

24 14 6 125.03 62.63 139.00 69.5 7.0 1239.22 615.22 427.3 2 2.00 8.16 3.17 5.6 0.098 0.85 3.81 7.0
trace Gravel

Gray sandy silty CLAY

30 20 10 125.03 125.03 139.00 139.0 7.0 2489.52 1865.52 1240.4 3 2.00 8.16 6.33 5.6 0.098 0.85 13.70 20.0
trace Gravel

Reddish yellowish gray

40 30 10 124.90 62.50 570.00 354.5 8.0 3738.52 2490.52 2178.0 8 2.21 8.61 17.05 6.4 0.112 0.85 38.93 56.0
sandy silty CLAY

Brown gray SAND

50 40 10 122.84 60.44 0.00 285.0 28 4966.92 3094.92 2792.7 9 17.96 31.80 280.16 22.4 0.413 0.85 72.68 352.8
some silt, trace Clay

Brown gray SAND

60 50 10 122.84 60.44 0.00 0.0 28 6195.32 3699.32 3397.1 15 17.96 31.80 340.79 22.4 0.413 0.85 113.02 453.8
some silt, trace Clay

Gray silty CLAY

70 60 10 117.74 55.34 364.00 182.0 5 7372.72 4252.72 3976.0 4 1.64 7.34 7.46 4 0.070 0.85 125.97 133.4
trace Sand

Gray silty CLAY

80 70 10 117.74 55.34 364.00 364.0 5 8550.12 4806.12 4529.4 4 1.64 7.34 14.93 4 0.070 0.85 151.88 166.8
trace Sand

Gray silty CLAY

90 80 10 122.70 60.30 924.00 644.0 6 9777.12 5409.12 5107.6 15 1.82 7.74 27.83 4.8 0.084 0.85 197.71 225.5
trace Sand

Brownish gray silty CLAY

100 90 10 124.21 61.81 1529.00 1226.5 7 11019.22 6027.22 5718.2 23 2.00 8.16 55.89 5.6 0.098 0.85 285.01 340.9
same Sand

Brownish gray silty CLAY

110 100 10 124.21 61.81 1529.00 1529.0 7 12261.32 6645.32 6336.3 2.00 8.16 69.68 5.6 0.098 0.85 393.83 463.5
same Sand 25
γ = Unit weight ofSoil (lb/ft3)
бv0' = (б1'+б2')/2
γ' = Effective unit weight of soil (lb/ft3)
Nc,Nq = Bearing capacity factor
δ = 0.8φ
φ Qb = Nc Cu Ab Qb = Nq бv0' Ab ( in sand )
C = Undisturbed undrained cohesion (lb/ft2)

CU = Average undisturbed undrained cohesion (lb/ft2) α = Adhesion factor Qs = α Cu As ( in clay ) Qs = Ks бv0' tan δ As ( in sand )

φ = Angle of friction(degree) Qb = Bearing resistance (Kip)

Qs = Shaft resistance (Kip)

б = Overburden pressure at pile base(lb/ft2)

б' = Effective overburden pressure at pile base(lb/ft2) Ks = 0.315 ( Ks / Ko = 0.7 , where Ko = 0.45 )
PILE CAPACITY

BORE HOLE NO.(2)

Pile size = 32 in Ø Ab = π/4(322) = 5.59 ft2 Perimeter, pD= 8.37333333 ft WT = 3 ft

Depth PileLength Thickness Pile

Soil Description γ γ' C CU φ б б' бvo ' SPT,N Nq Nc Qb kip δ tan δ α ΣQs
(ft ) (ft ) z capacity

Brown gray clayey

20 8 4 120.05 57.65 153.00 153.0 6.0 480.20 230.6 115.3 2 1.82 7.74 1.17 4.8 0.084 0.85 0.20 1.4
sandy SILT

Brown gray clayey

24 14 6 120.05 57.65 153.00 153.0 6.0 1200.50 576.50 403.6 2 1.82 7.74 6.61 4.8 0.084 0.85 6.74 13.3
sandy SILT

Brown gray clayey

30 20 10 120.05 120.05 153.00 153.0 6.0 2401.00 1777.00 1176.8 2 1.82 7.74 6.61 4.8 0.084 0.85 17.63 24.2
sandy SILT

Gray silty CLAY

40 30 10 120.65 58.25 421.00 287.0 6.0 3607.50 2359.50 2068.3 5 1.82 7.74 12.40 4.8 0.084 0.85 38.05 50.5
some Sand

Gray silty SAND

50 40 10 121.95 59.55 0.00 210.5 25 4827.00 2955.00 2657.3 8 12.81 25.26 190.18 20 0.365 0.85 25.58 215.8
trace Clay

Yellownish gray sandy silty

60 50 10 125.80 63.40 644.00 322.0 7 6085.00 3589.00 3272.0 9 2.00 8.16 36.63 5.6 0.098 0.85 34.89 71.5
CLAY trace Grave

Yellownish gray sandy silty

70 60 10 125.80 63.40 644.00 644.0 7 7343.00 4223.00 3906.0 7 2.00 8.16 29.35 5.6 0.098 0.85 80.73 110.1
CLAY trace Grave

Gray CLAY & SILT

80 70 10 121.92 59.52 770.00 707.0 6 8562.20 4818.20 4520.6 9 1.82 7.74 30.55 4.8 0.084 0.85 131.05 161.6
trace Sand, trace Gravel

Brownish light gray

90 80 10 124.91 62.51 753.00 761.5 8 9811.30 5443.30 5130.8 14 2.21 8.61 36.63 6.4 0.112 0.85 185.24 221.9
silty sandy CLAY

Brownish gray silty CLAY

100 90 10 127.78 65.38 1537.00 1145.0 7 11089.10 6097.10 5770.2 24 2.00 8.16 52.18 5.6 0.098 0.85 266.74 318.9
Trace Sand

Brownish gray silty CLAY

110 100 10 127.78 65.38 1537.00 1537.0 7 12366.90 6750.90 6424.0 25 2.00 8.16 70.04 5.6 0.098 0.85 376.13 446.2
Trace Sand
γ = Unit weight ofSoil (lb/ft3)
бv0' = (б1'+б2')/2
γ' = Effective unit weight of soil (lb/ft3)
Nc,Nq = Bearing capacity factor
δ = 0.8φ
φ Qb = Nc Cu Ab Qb = Nq бv0' Ab ( in sand )
C = Undisturbed undrained cohesion (lb/ft2)

CU = Average undisturbed undrained cohesion (lb/ft2) α = Adhesion factor Qs = α Cu As ( in clay ) Qs = Ks бv0' tan δ As ( in sand )

φ = Angle of friction(degree) Qb = Bearing resistance (Kip)

Qs = Shaft resistance (Kip)

б = Overburden pressure at pile base(lb/ft2)

б' = Effective overburden pressure at pile base(lb/ft2) Ks = 0.315 ( Ks / Ko = 0.7 , where Ko = 0.45 )