steel design calculation for bridge false works

GENERAL NOTES:a. Analysis of frame is computed using Staad Pro V07 Analysis Software. Other members subjected to design are considered to be simply supported.b. For beam and column design, consider longitudinal section at centerline.

1. Interior Columns - carries 1 girder load and its components.2. Exterior Columns - carries only ½ of Interior column load and its components. Therefore, Design Interior Columns Only.

c. Design procedures for adequacy requirements are done by:1. Staad Pro V07 Program ………………………………………… Code: AISC-Allowable Stress Design

Members: H-Beam & Column (W12x65) AISC Steel2. Detailed Calculation by Hand ………………………….. NSCP 2001-Allowable Stress Design (Counter-Cheking) Members: H-Beam & Column (BH300x92) ASEP Steel

d. Sequence of section investigation and design:1. Plywood Sheathing (1" thk.) ……………………………………ACI 3472. Wood Joist (2"x4") @ 200mm O.C………………………….. NSCP-ASD3. SSP (Type-II) …………………………………………………………NSCP-ASD4. H-Beam as Girders (300x300mm) NSCP/AISC-ASD5. H-Beam as Columns (350x350mm) NSCP/AISC-ASD Note: USE 300x300mm section in design consideration.

e. Lateral Loads are to be neglected in the design. However, provide bracing supports for the frame, especially on the transverse section if in case there are lateral forces that may occur.

DESIGN CRITERIA and SPECIFICATIONS

I. LIVE LOADSa. Liveload (Special Loads for Construction)…………………………… Sect. 205.3.4, T205-2, Pg.2-9

II. DEAD LOADSa. Concrete ………………………………………………………………………… Sect. 204.2, T204-1, Pg.2-5b. Steel Materials………………………………………………………………… Sect. 204.2, T204-1, Pg.2-5c. Steel Forms ………………………………………………………………..d. Wood Bracings……………………………………...……………………….e. Formworks (includes pylwood & joists) ………………………………

IV. ALLOWABLE STRESSESa. Structural Steel Materials

DESIGN SCHEME:

276.0 Mpa

STRUCTURAL ANALYSIS AND DESIGN(based on NSCP 2001 Vol. 1 - 5 th Ed., AISC-ASD, ACI 347)

PROPOSED FALSEWORK DESIGN FOR MOAWA BRIDGE(Simple Steel Frames with Diagonal Bracings)

7.20 KPa

24.00 KN/m³77.30 KN/m³9.000 KPa1.400 KPa1.200 KPa

Bridge Name: Moawa Bridge, BoholLength of Bridge: 32.0 mSpan Length: 3.6m to accommodate 9-pcs of SSP per span [Falsework]

INPUT DATA and DESIGN CRITERIA

Prestressed I-Girder = AASHTO Specs DEAD LOADS: Kpa psf KN/m Area (Total) = AASHTO Specs Steel Forms = 9.000 188.03 5.95

Girder Width = AASHTO Specs Wood Bracings = 1.400 29.25 0.93 γ(Unit Weight) = Concrete = 22.25 464.86 14.71

γ(Linear Weight) = Formwork = 1.200 25.07 [Plywood & Joist] Allow. ðdeflection = Timber Sub-Total = 33.850 707.21 [Girder Components]Allow. ðdeflection = Steel

LIVELOADS:Working Load = 7.200 150.4 [Special Loads]

I. DESIGN OF SHEATHING

Material Properties: Source: (ACI 347 Table 4-2,4-3)

Plywood =Bending, Fb =Shearing, Fv =

E = S =I =

Ib/Q =spacing, s = [(0.661-0.050)/3] s s s

Support = 3 or more spans

Loadings: (Consider 1-ft strip of plywood) Loading Combination: (NSCP Sect. 203.3.1 - ASD)DL =

=LL = Wu = (DL + LL) =

=

wu = [self-weight included]

From ACI 347 Using Table 7-1 (Safe Spacing of Supports)

Note: Failure on Plywood if we use t=1/2" or even 3/4" with joist spaced @ 200mm O.C.

[Adequate]

707.21 lb/ft

Spacings Bending, Fb Rolling Shear, Fv ∆=l/360 ∆=1/16"(in.) 10.95 √(FbS/wu) (20FvS/wu)(Ib/Q)+1.5 1.693√(EI/wu) 3.234√(EI/wu)

1545 Psi

Status [Adequate] [Adequate] [Adequate]Therefore

(Based on NSCP 2001 Vol. 1, 5th Edition and ACI 347 )

0.39 Mpa10,345 Mpa

5,730 mm² 8.882 in²

10,881 mm³

STEEL and WOOD SECTION DESIGN and INVESTIGATIONPCDG Formwork and Falsework

57 Psi1500000 Psi0.664 in³

176,066 mm^4 0.423 in^4

24.024 KN/m³ 153 lb/ft³

Type IV-B0.6123 m²0.661 m

USE: Ordinary Plywood (1.0" thk) with Joist spaced @ 200mm O.C.

1.0" thk

Design Section is ADEQUATE

150.43 lb/ft

857.6 lb/ft

0.204 m 8.03 in

Max. Spacing 11.98 in 9.34 in 15.29 in 16.85 inActual Spacing 8.03 in 8.03 in 8.03 in 8.03 in

Check Act. < All Act. < All Act. < All Act. < All

10.7 Mpa

L/360L/180

14.710 KN/m 1008 lb/ft

707.21 psf

150.43 psf 857.640 lb/ft

0.661

TABLE 7-1

II. DESIGN OF WOOD JOIST

Material Properties: Source: (website: www.supertimber.com)

Coco Timber =b =d =

Bending, Fb =Shearing, Fv =

E = S =I =

Ib/Q =Unit Weight, γ =

spacing, s = s s sassumed length, L =

selfweight =Support = 3 or more spans

STEEL SECTION DESIGN and INVESTIGATIONPCDG Formwork and Falsework


Design Section is ADEQUATE0.400 m 15.74 in0.022 KN/m

50.000 mm100.00 mm13.1 Mpa1.30 Mpa 189 psi

1900 psi

4.33 KN/m³ 441 Kg/m³0.204 m 8.03 in

2" x 4"

3,100 Mpa 449500 psi83,333 mm³ 5.085 in³4,166,667 mm^4 10.010 in^43,333 mm² 5.166 in²

0.40 0.40

Loadings: Loading Combination: (NSCP Sect. 203.3.1 - ASD)DL =

= (DL)(s)LL = Wu = (DL + LL) =

= (LL)(s)

wu = [including self-weight]Mu = 1/8(Wu)(L²)Vu = ½(Wu)(L)

ð ACT = (5/384) (WuL4 / EI)

Note: Not critical as long as SSP are placed side by side with no gaps.

III. DESIGN OF SSP Type-II (Deck Flooring)

Material Properties: Source: Sumitomo SKSP Steel Sheet PilesNote: As per one (1) ssp

SSP =b =d =t =A =fy =

Allow. Bending, Fb = 0.60fy (50% Eff.)Allow. Shearing, Fv = 0.40fy (50% Eff.)

E = S = I =

Unit Weight, γ =span length, L = 2.250 m

selfweight =Widthgirder = 0.661 m

Loadings: Tributary Area:Girder Components = (Girder)(Wgirder)(s) ÷ 9pcs Span Length, L =

= (33.85)(0.661)(3.6)÷ 9pcs Span Spacing, s ==

Selfweight = (γ)(Area)(L)= (0.47)(0.006118)(2.25) Pu=

DL = [per ssp]

Live Load = (LL)(L)(s) ÷ 9pcs= (7.2)(2.25)(3.6)÷ 9pcs

LL = [per ssp]6.480 KN

Design Section is ADEQUATE

8.950 KN

0.006 KN8.956 KN

2.250 m3.600 m

0.003 KN/m

0.141 KN-m1.413 KN0.182 mm

Stresses Bending, Fb Shearing, Fv Deflection, ð6M/bd² 3V/2A (5WuL

4)/384EIActual 1.692 MPa 0.424 MPa 0.182 mm

Type II400 mm100 mm

82.8 Mpa

10.50 mm6,118 mm²

Allowable 13.100 MPa 1.300 MPa 2.22 mmCheck Act. < All Act. < All Act. < AllStatus ADEQUATE ADEQUATE ADEQUATE

Therefore USE: Wood Joist 50x100mm (2" x 4") @ 200mm O.C.



33.85 Kpa

7.20 Kpa

276.0 Mpa

0.47 KN/m³12,400,000 mm^4152,000 mm³200,000 Mpa55.2 Mpa

6.905 KN/m

0.158 KN/m

7.063 KN/m

7.063 KN/m

0.40 0.40

Summary: Loading Combination: (NSCP Sect. 203.3.1 - ASD)

DL =LL = Pu = (DL + LL) =

Pu = [self-weight included as per (1) ssp]Mu = Pu L / 4Vu = Pu / 2

ð ACT = Pu L³ / 48EI

IV. DESIGN OF GIRDERS (H-Beam 300x300)

Material Section and Properties: Source: (ASEP Steel Handbook 1994)

Built-Up Shape = Flange Width-Thickness RatioA = mm² bf/2tf = 12.50d = mmtw = mm Web Depth-Thickness Ratio tf =12bf = mm d/tw = 37.50tf = mm

Linear γ = KN/m [92.19] kg/mw = mm

k (crippling use) = mm [t f + w] tw =8

rx = mmry = mmrt = mmSx = mm³Sy = mm³Ix = mm4

Iy = mm4

E = Mpafy = Mpa

Span Length, L = mm [Actual Un-Braced Length in Bending]Un-Supported , Lb = mm [simply supported] [Max. Un-Braced Length of Compression]

Length, Lc = min { [200bf /√fy] , [137900 / (fyd ÷ bf tf)] }=

L / rT = 43.11 mm

7.0019.00

200,000

3,600.003,600.00

Allowable 82.800 MPa 55.200 MPa 6.250 mmCheck Act. < All Act. < All Act. < AllStatus ADEQUATE ADEQUATE ADEQUATE

Therefore USE: SSP Type-II for Deck Flooring placed side by side.

BH 300 x 9211,744

bf = 300

300

d =

300

8.00300

0.904

132.60

72,000,000

6.480 KN8.956 KN

8.683 KN-m7.718 KN

Stresses Bending, Fb Shearing, Fv Deflection, ð Mu / Sx Vu / A Pu L³ / 48EI

Actual 57.125 MPa 1.262 MPa 1.477 mm



78.3083.50

1,377,000480,000

x-axis

y-axis

207,000,000Design Section is ADEQUATE

12.00

276

3,611.58 mm

15.436 KN

1.477 mm

15.436 KN

Determine Allowable Bending Stress, Fb:Determine Allowable Shearing Stress, Fv:

a. (bf/2tf) ≤ (170/√fy) a. (bf/2tf) ≥ (170/√fy) a. Lb ≥ Lc

12.50 ≤ 10.23 12.50 ≥ 10.23 ≥ 3611.58

b. (d/tw) ≤ (1680/√fy) b. (bf/2tf) ≤ (250/√fy) b. If Stress in Tension37.5 ≤ 101.12 12.50 ≤ 15.05 Fb = 0.60fy

c. Lb ≤ Lc c. Lb ≤ Lc c. If Stress in Compression≤ 3611.58 ≤ 3611.58 Fb =

d. If a,b & c =YES (x) Whend. USE Fb = 0.66fy Fb=min(x,y) 703,270Cb 3,516,330Cb

x = 0.60fy fy fyy =fy [0.79 - 0.000762 (bf/2tf) √fy] =fy{2/3 - [fy(L/rt)² / 10.55e6 Cb]}

(y) When 3,516,330Cb

fy =(1,172,100 Cb) / (L/rt)²

(z) For Any Value of L/rtRESULTS: =(82,740 Cb) / (Ld ÷ bf tf)

Fb = [see table]Fv = [0.40fy] Note: Cb=1.75+(1.05M1/M2)+0.30(M1/M2)² ≤ 2.3

USE: Cb=1.0 [Conservative Value]

Loadings: Tributary Area:Girder = (girder)(Wgirder) Wgirder =

= (33.85)(0.661) Span Length, L == Span Spacing, s =

SSP = (γ)(s)(Assp)(9.0 pcs) ÷ L

= (0.47)(2.25)(0.006118)(9.0 pcs) ÷ 3.6=

Selfweight = (γlinear)(L)= (0.904)(3.6)=

Dead Load (TOTAL) =

LL = (LL)(s)= (7.2)(2.25)

Live Load (TOTAL) =

Summary: Loading Combination: (NSCP Sect. 203.3.1 - ASD)

DL =LL = Wu = (DL + LL) =

wu = [self-weight included]Mu = [see Staad Pro. V7 analysis results] Beam No. 1Vu = [see Staad Pro. V7 analysis results] Beam No. 1

ð ACT = (5/384) (WuL4 / EI)

0.661 m

3,600.00 3,600.00

3,600.00

Fb = 165.60

165.60 MPa110.40 MPa

51.520 KN-m87.120 KN2.211 mm

165.6



N/A

N/A

N/A

RequirementsCOMPACT

NO

YES

YES

N/A

NON-COMPACTRequirements

YES

YES

YES

COMPACT or NON-COMPACTRequirements [USE: min of b,c]

NO

N/A

N/A

max (x,y,z)

16.200 KN/m

3.600 m

41.85 KN/m

2.250 m22.375 KN/m

25.645 KN/m

25.645 KN/m16.200 KN/m

0.016 KN/m

3.254 KN/m

41.845 KN/m

≤ L/rt ≤ ≤≤

L/rt >

Check: Local Web Yielding and Web Crippling R(actual) = N = 300 K = 19

dist. = 0.0

Note: PROVIDE adequate connection to steel pile caps. (Welding Connection)

V. DESIGN OF STEEL BEAM USED AS COLUMN SUPPORT

Material Section and Properties: Source: (ASEP Steel Handbook 1994)

Built-Up Shape = Flange Width-Thickness RatioA = mm² bf/2tf = 12.50d = mmtw = mm Web Depth-Thickness Ratio tf =12bf = mm d/tw = 37.50tf = mm

Linear γ = KN/m [92.19] kg/m

rx = mm tw =8ry = mmrt = mmSx = mm³Sy = mm³Ix = mm4

Iy = mm4

E = Mpafy = Mpa

Column Length, L = mmUn-Supported , Lb = mm

Length, Lc = min { [200bf /√fy] , [137900 / (fyd ÷ bf tf)] }=

Select Type = see NSCP Table Length Factor, k = see NSCP Table

kL / rt = 86.2275Cc = √(2 π² E / fy)

= 119.598CHECK: Slenderness Ratio Requirements (Main Compression Member)

kL / rt = ≤ 200≤ 200 [OK]

PCDG Formwork and Falsework(Based on NSCP 2001 Vol. 1, 5th Edition and ACI 347 )

Status

Act. < AllAct. < All Act. < All

Therefore

R/[tw(N+5k)]d from end>d

R/[tw(N+2.5k)]

STEEL SECTION DESIGN and INVESTIGATION

tw²[1+3(N/d)(tw/tf)1.5

Status ADEQUATE ADEQUATE ADEQUATETherefore USE: H-Beam (300x300) as Girder spaced @ 2.250m O.C.

Stresses

87.120 KNR = 177.2 (factor)

d from end>d

Stresses Bending, Fb Shearing, Fv Deflection, ð Mu / Sx Vu / d tw (5Wu L

4)/384EI

Actual 37.415 MPa 36.300 MPa 2.211 mmAllowable 165.600 MPa 110.400 MPa 10.000 mm

Check

d from end ≤ dN/A USE

Results 31.338 MPa182.160 MPa

Act. < AllADEQUATE

USE: H-Beam (300x300) as Girder spaced @ 2.250m O.C.

N/A

Check

USE237.181 KN87.120 KNAct. < All

ADEQUATE

12.00x-axis0.904

132.60

[strong axis]

78.3083.50

1,377,000 bf = 300480,000

207,000,000

Factor

x √(Fyw tf / tw)

3,611.58 mm

d from end ≤ d

2.656 KN

Allowable = (0.66fy)

72,000,000200,000

2766,000

y-axis

BH 300 x 9211,744

3008.00300

d =

300

R = 89.3 (factor)

6,000

1.2(c)

86.23

Determine Allowable Bending Stress, Fb:Determine Allowable Shearing Stress, Fv:

a. (bf/2tf) ≤ (170/√fy) a. (bf/2tf) ≥ (170/√fy) a. Lb ≥ Lc

12.50 ≤ 10.23 12.50 ≥ 10.23 ≥ 3611.58

b. (d/tw) ≤ (1680/√fy) b. (bf/2tf) ≤ (250/√fy) b. If Stress in Tension37.5 ≤ 101.12 12.50 ≤ 15.05 Fb = 0.60fy

c. Lb ≤ Lc c. Lb ≤ Lc c. If Stress in Compression≤ 3611.58 ≤ 3611.58 Fb =

d. If a,b & c =YES (x) Whend. USE Fb = 0.66fy Fb=min(x,y) 703,270Cb 3,516,330Cb

x = 0.60fy fy fyy =fy [0.79 - 0.000762 (bf/2tf) √fy] =fy{2/3 - [fy(L/rt)² / 10.55e6 Cb]}

(y) When 3,516,330Cb

fy =(1,172,100 Cb) / (L/rt)²

(z) For Any Value of L/rtRESULTS: =(82,740 Cb) / (Ld ÷ bf tf)

Fb = [see table]Fv = [0.40fy] Note: Cb=1.75+(1.05M1/M2)+0.30(M1/M2)² ≤ 2.3

USE: Cb=1.0 [Conservative Value]

Determine Allowable Axial Stress, Fa:FS =

Since,kL/rt [<] Cc

Therefore,

Fa = {1 - [(kL/r)² ÷ 2 Cc²]} x fy / FS Fa = (12 π² E) / [23 (kL/r)²]= =

USE: Fa =

Pu = [see Staad Pro. V8i analysis results] Column No. 8Selfweight = [(Linear γ)(Length of Column)]

Pile Cap Weights = [(Linear γ)(Length of Beam)]Accecories = (Assume 1% of Pu)

Total Pu =

Mu = [see Staad Pro. V07 analysis results] Column No. 8fa = [Pu / A] Actual Compressive Stressfb = [Mu / Sx] Actual Bending Stress

Summary:fa = fb =Fa = Fb =

2.034 KN1.636 KN172.734 KN

108.065 MPa



165.60

14.708 Mpa

YES YES

NO NO6,000.00 6,000.00

N/A

= 1.89

When kL/r < Cc [Short-Columns] When kL/r > Cc [Long Column]

108.065 Mpa

165.48

max (x,y,z)

N/A N/A130.31

163.640 KN

14.708 Mpa108.065 Mpa

0.006 Mpa165.480 Mpa

N/A

165.48

165.48 MPa110.40 MPa

2.810 KN-m

0.006 Mpa

COMPACT NON-COMPACT COMPACT or NON-COMPACTRequirements Requirements Requirements [USE: min of b,c]

Fb = 165.48

NO YES YES6,000.00

5.424 KN

5/3 + 3(KL/r) - (KL/r)³8Cc 8Cc³

≤ L/rt ≤ ≤≤

L/rt >

fa + Cm fb ≤ 1.0Fa (1-fa/Fe') Fb

Cm=0.60-0.4M1/M2 ≤ 0.4Cm =0.85 (sidesway) = 0.85Fe'=(1030000) / (KL/r)² =138.53

CHECK Shearing Stress for Columns:

Vu = [see Staad Pro. V07 analysis results]fv = [Vu / d tw]Fv = [Vu / d tw]

Check = [fv < Fv] [Satisfactory]

STAAD PRO V2007 ANALYSIS

wu = [from Design IV-Steel Beam Design]41.850 KN/m

(fa / Fa) = 0.14References: (interaction)

Status SAFE

ThereforeColumns Section is Adequate for Both Bending and Compression

0.136 when > 0.15Check ≤ 1.0

Governs N/A (fa/Fa)+(fb/Fb) ≤ 1.0

Interaction Value

(fa / Fa) ≤ 0.15 (fa / Fa) > 0.15Requirements Requirements when ≤ 0.15

Check



0.690 KN0.288 Mpa110.400 Mpa

MOMENT DIAGRAM

SHEAR DIAGRAM

AXIAL FORCES



steel design calculation for bridge false works

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