Design of box culvert bridge

DESIGN CRITERIA

Structural Design Criteria of the Proposed

CASTELLANO BRIDGE MAY 2013

1.0 GENERAL

This document defines the structural engineering requirements and design

philosophy for the structure. Included herein is a list of applicable codes, standards, and specifications used as reference in determining the parametric values; the basis upon which the design criteria are established and methods/procedures used for the analysis and design of the structures included in Castellano Bridge.

Noteworthy among the design requirements is the DPWH Advisory for

Seismic Design of Bridges, Dept. Order No. 75 that specifies for earthquake analysis the requirements of AASHTO Guide Specifications for Seismic Design.

Following the above-mentioned DPWH Advisory and the AASHTO Guide for

Seismic Design, the followings are the important design concepts adopted in our structural design:

a. The stiffness of the bridge as a whole was considered in the

analysis b. The provision of column transverse reinforcements for

confinement at expected plastic hinge regions. c. The adaptation, in general of the design forces and analysis, and

design procedures for piers, abutments and foundation as required by the AASHTO Guide Specifications for Seismic Design.

2.0 CODES AND STANDARDS

A summary of the codes and industry standards used in the design shall be as follows:

2.1 Design Codes and Standards

2.1.1 DPWH Standard Specification, Highway, Bridges and

Airport, 1995. 2.1.2 National Structural Code of the Philippines (NSCP), Volume

2 - Bridges, 1997. 2.1.3 American Association of State Highway and Transportation

Officials (AASHTO), Standard Specifications for Highway Bridges, 17th Edition, 2002.

2.2 Material Codes and Standards 2.2.1 American Society for Testing Materials (ASTM).

Structural Design of the Proposed


3.0 BRIDGE DESCRIPTION

Based on requirement as indicated in design report a proposed new bridge is to be constructed to replace the existing Castellano Bridge.

The new bridge shall have a new span of 14.0 meters with no central pier and shall function as a box culvert serving as spillway for flush flooding during heavy rain conditions. The same level as the existing bridge shall be maintained.

The new bridge shall be constructed using reinforced concrete materials. The superstructure shall be flat slab from end to end of the abutment walls. The bridge structure shall be founded on four (4) bored pile deep foundations based on the recommendation of the geotechnical study. The river bed under the bridge shall be covered by reinforced concrete slab for smooth channel flow.

Separate apron structures with cut-off walls and compacted stones at ends are provided at the upstream and downstream side of the bridge to protect surrounding areas from the destructive effect of scouring. The new apron retaining wall and floor slab structures shall be founded using shallow mat footing and shall be provided with edge beams/walls to minimize the effect of foundation settlements due to the existing poor soil condition.

PROFILE OF THE PROPOSED CASTELLANO BRIDGE



4.0 MATERIALS 4.1 Concrete The following concrete compressive strengths (f’c) shall be based on

the 28-day strength of 150 x 300 mm cylinder:

Structural Member f’c Box Culvert 28.0 MPa (4,000 Psi) Bored Pile 21.0 MPa (3,000 Psi) Sidewalk, railings, parapet, median 21.0 MPa (3,000 Psi) Other concrete 21.0 MPa (3,000 Psi) Lean concrete 17.0 MPa (2,400 Psi) Non Shrink Grout 58.0MPa (8,000Psi) 4.2 Reinforcing Steel Steel reinforcing deformed bars shall conform to AASHTO M31

ASTM A615) Grade 40 (276 MPa) for 10mm diameter below and Grade 60 (414MPa) for 12mm diameter above.

5.0 STRUCTURAL DESIGN CONCEPT

5.1 Method of Analysis 5.1.1 Superstructure

The box culvert bridge superstructure was modeled in three-dimensional space frame using STAAD Pro 2007 software.

The maximum stresses produced by the design loads (combination of loads will be used to investigate and strengthened every component of the superstructure.

5.1.2 Substructure

The substructures of the bridges were analyzed using the Multimode Spectral Analysis Method (Procedure 3 of Div. IA, Seismic Design, AASHTO 2002). The structures were modeled as three dimensional space frames and the analysis was performed using a structural analysis computer program called STAAD Pro 2007. The member forces and displacements were estimated by combining the respective response quantities from individual modes by the Complete Quadratic Combination (CQC) method as recommended in AASHTO Guide Specification for Seismic Design Section 4.5.5



5.1.2.1 Determination of Elastic Forces and Displacements The elastic forces and displacements shall be determined independently along two perpendicular axes by use of analysis procedure. Typically, the perpendicular axes are the longitudinal and transverse axes of the bridge. 5.1.2.2 Combination of Orthogonal Seismic Forces A combination of orthogonal seismic forces is used to account for the directional uncertainty of earthquake motions and the simultaneous occurrences of earthquake forces in two perpendicular horizontal directions. The elastic seismic forces and moments resulting from analyses in the in the two perpendicular horizontal directions shall be combined to form two (2) load cases as follows: LOAD CASE 1: Seismic forces and moments on each of the principal axes of a member shall be obtained by adding 100 percent of the absolute value of the member elastic seismic forces and moments resulting from the analysis in one of the perpendicular (longitudinal) directions to 30 percent of the absolute value of the corresponding member elastic seismic forces and moments resulting from the analysis in the second perpendicular direction (transverse). (NOTE: The absolute values are used because a seismic force can be positive or negative.)

LOAD CASE 2: Seismic forces and moments on each of the principal axes of a member shall be obtained by adding 100 percent of the absolute value of the member elastic seismic forces and moments resulting from the analysis in the second perpendicular direction (transverse) to 30 percent of the absolute value of the corresponding member elastic seismic forces and moments resulting from the analysis in the first perpendicular direction. For seismic design of structural components, Loading Combination VII shall be modified. Group Load = 1.0(D + B + SF + E + EQM or EQF) Where, D = dead load B = buoyancy SF = stream flow pressure E = earth pressure



EQM or EQF = elastic seismic force for either Load Case I or Load Case 2 modified by dividing the appropriate R-Factor

5.2 Method of Design

5.2.1 Reinforced Concrete Structural Member

Design of reinforced concrete members shall be based on Strength Design Method (Load Factor Design) shall be used for the design of reinforced concrete structural members (abutments, piers, pile caps, piles, deck slabs, wing walls, approach slabs), wherein the required strength of a section is the strength necessary to resist the factored loads and forces applied to the structure in the load combinations. All sections of structures shall have design strengths at least equal to the design strength as specified in Article 8.16 of NSCP Volume 2, Bridges – Part A, 2nd Edition, 1997.

6.0 LOADINGS 6.1 Dead Loads

The dead loads shall consist of the weight of the entire structure including the roadway, sidewalks, car tracks, pipes, conduits, cables, and other public utility services. The following unit weights of construction materials were used in computing the dead loads.

Materials Unit Weight

(kN/m3) Concrete, plain or reinforced 24

Compacted earth, sand, gravel, or ballast

18.9

Structural Steel 77 Cast Iron 71

Water (without sediment) 9.81 Bituminous wearing surface

(50 mm thk) 1.05 kPa

6.2 Live Loads

The live loads shall consist of the weight of applied moving loads of the vehicles, cars and pedestrians. 6.2.1 Highway Loads



The highway live loading on the bridges or incidental structures shall conform to the following highway live load, whichever governs; 6.2.1.1 MS18 (HS20) Loading

For bridges that may carry heavy truck traffic the minimum live load shall be MS18 (HS20) as designated herein and shown in the following figures.



STANDARD MS (HS) TRUCKS 6.2.1.2 Alternate Military Loading

The alternate military loading shall consist of two axles, 1.22m apart with each axle weighing 107kN (see figure below).

6.2.1.3 Permit Design Loading

The permit loading was developed to ensure sufficient bridge live load capacity to carry extra legal live loads allowed by permit (see figure below).

6.2.2 Impact

Highway Live Loads shall be increased for those structural elements in

Group A, below, to allow for dynamic, vibratory and impact effects. Impact allowance shall not be applied to items in Group B. It is intended as part of the loads transferred for superstructure to



substructure, but shall not be included in loads transferred to footings nor to those parts of piles or columns that are below ground.

a) Group A – Impact shall be included (1) Superstructure, including legs of rigid frames. (2) Piers, (with or without bearings regardless of type)

excluding footings and those portions below the ground line.

(3) The portions above the ground line of concrete or steel piles that support the superstructure.

b) Group B – Impact shall not be included

(1) Abutments, retaining walls, piles except as specified in

6.2.2.a (3). (2) Foundation pressures and footings. (3) Timber structure. (4) Sidewalk loads. (5) Culverts and structures having 0.90m or more cover. Impact Formula

The amount of this allowance or increment is expressed as a fraction of live load stress, and shall be determined by the following formula:

38

24.15

LI

Where,

I = impact factor (maximum of 30 percent) L = length in meters of the portion of the span that is

loaded to produce the maximum stress in the member

6.3 Sidewalk, Curb, and Railing Loading

6.3.1 Sidewalk Loading

Sidewalk floors, stringers and their immediate supports shall be designed for a live load of 4070 Newton per square meter of sidewalk area. Girders, trusses, arches, and other members shall be designed for the following sidewalk live loads: Span 0 to 7.80 m in length ……………….. 4070 Pa Span 7.80 to 30.5 m in length ……………. 2870 Pa Span over 30.5 m in length according to the formula



2.15

7.16800,43435,1

W

LP

In which P = live load in Pa. max. 2870 Pa. L = loaded length of sidewalk in meters W = width of sidewalk in meters Bridges for pedestrian and/or bicycle traffic shall be designed for a live load of 4070 Pa. 6.3.2 Railing Loading Although the primary purpose of traffic railing is to contain the average vehicle using the structure, consideration should be given to (a) protection of the occupants of a vehicle in collision with railing, (b) protection of other vehicles near the collision, (c) protection of vehicles or pedestrians on roadways underneath the structure, and (d) appearance and freedom of view from passing vehicles. 6.4 Seismic Loads

Structure shall be designed to resist earthquake motions by considering the relationship of the site to active faults, the seismic response of the soil at the site, and the dynamic response characteristics of the total structure in accordance with the criteria as prescribed in Section 21 of Division IA- Seismic Design of the AASHTO Standard Specifications for Highway Bridges, 17th Edition, 2002.

6.4.1 Acceleration Coefficient The coefficient A to be used for the area shall be 0.4. 6.4.2 Importance Classification

An importance classification (IC) of I shall be assigned for the structure with a classification of being an essential structure.

6.4.3 Seismic Performance Categories

Seismic Performance Category (SPC) D shall be assigned to the structure, based on the Acceleration Coefficient (A) of 0.40g and the Importance Classification (IC) of I.



6.4.4 Site Effect

The effects of site condition on bridge response shall be determined from site coefficient (S) based on soil profile types defined as follows:

Acceleration Coefficient Importance

Classification (IC)

A I II A ≤ 0.29 C C

0.29 < A D C

SOIL PROFILE TYPE I is a profile with either 1) Rock of any characteristics, either shale-like or crystalline

in nature (such material may be characterized by a shear wave velocity greater than 760m/sec, or by other appropriate means of classification); or

2) Stiff soil conditions where the soil depth is less than 60m and the soil types overlying rock are stable deposits of sands, gravels, or stiff clays.

SOIL PROFILE TYPE II is a profile with stiff clay or deep cohesionless conditions where the soil depth exceeds 60m and the soil types overlying rock are stable deposits of sands, gravels, or stiff clays. SOIL PROFILE TYPE III is a profile with soft to medium-stiff clays and sands, characterized by 10m or more of soft to medium-stiff clays with or without intervening layers of sand or other cohesionless soils. In location where the soils properties are not known in sufficient detail to determine the soil profile type or where the profile does not fit any of the three types, the site coefficient for Soil Profile Type II shall be used. The soil profile coefficients apply to all foundation types including pile supported and spread footings.

6.4.5 Site Coefficient

The site coefficient (S) approximated the effects of the site conditions on the elastic coefficient or spectrum of Article 21.5.2 of NSCP Volume 2 - Bridges, 2nd edition, 1997, is given below:



Soil Profile Type I II III S 1.0 1.2 1.5

6.4.6 Response Modification Factors

Seismic design forces for individual members and connections of bridges classified as SPC C and D are determined by dividing the elastic forces by the appropriate Response Modification Factor (R) as specified in Article 21.4.6 of NSCP Volume 2 - Bridges, 2nd edition, 1997. The Response Modification Factors for the various components are given below Substructure1 R Connections R

Wall Type Pier2 2 Superstructure to Abutment 0.8 Reinforced Concrete Pile Bents

a. Vertical Piles only 3 Expansion Joints within a Span

b. One or more Batter Piles 2 of the Superstructure 0.8

Single Columns 3 Columns, Piers or Pile Bents to

Steel or Composite Steel and Cap Beam or Superstructure3 1.0

Concrete Pile Bents Columns or Piers to

a. Vertical Piles only 5 Foundations3 1.0 b. One or more Batter Piles 3 Multiple Column Bent 5

1The R-Factor is to be used for both orthogonal axes of the substructure. 2A wall-type pier may be designed as column in the weak direction of the pier provided all the provisions for columns in Article 21.8 of NSCP Volume 2 - Bridges, 2nd edition, 1997 are followed. The R-factor for a single column can then be used. 3For bridges classified as SPC C and D it is recommended that the connections be designed for the maximum forces capable of being developed by plastic hinging of the column bent as specified in Article 21.4.6.6 of NSCP Volume 2 - Bridges, 2nd edition, 1997. These forces will often be significantly less than obtained using an R-factor of 1.

6.5 Earth Pressure

6.5.1 Active Earth Pressure Coefficient



Lateral earth pressures shall be computed assuming active stress conditions and wedge theory using a planar surface of sliding defined by Coulomb’s Theory.

)sin()sin(

)'sin()'sin(1)sin(sin

)'(sin

2

2

ak

Where,

ka = active earth pressure coefficient ’ = effective unit weight ’ = effective angle of internal friction = angle of wall friction β = slope angle = wall face batter All angles are positive (+) as shown.

For seismic lateral earth pressures, the pseudo-static approach developed by Mononobe-Okabe specified in Division IA, Seismic Design of the AASHTO was used to estimate the equivalent static forces for seismic loads. The estimation of seismic design forces also accounted for structure inertial forces in addition to the equivalent static forces.

)cos(2coscos

)(cos2

aek

Where,

kae = total Mononobe-Okabe seismic lateral earth pressure coefficient H = height of soil face = unit weight of soil



= angle of friction of soil = arc tan (kh /1-kv) = angle of friction between soil and abutment β = backfill slope angle kh = horizontal acceleration coefficient kv = vertical acceleration coefficient

=

2

)cos()cos(

)sin()sin(1

i

i

6.5.2 Earth Load

2

2

1HkPa a

for normal condition

2)1(2

1HkkPa vae

for seismic condition

6.6 Load Combinations

Every structure component shall be designed to withstand the forces resulting from each load combination according to the requirements of Division I Article 3.22 and to the additional requirements of Division IA Article 7.2 (AASHTO Standard Specifications for Highway Bridges). The following Groups represent various combination of loads and forces to which a structure may be subjected. Each component of the structure, or the foundation on which it rests, shall be proportioned to withstand safely all group combinations of these forces that are applicable to the particular site or type. Group loading combinations for Service Load Design and Load Factor Design are given by: Group (N) = {βDD + βL (L + I) + βCCF + βEE + βBB + βSSF + βWW + βWLWL + βLLF + βR ( R + S + T ) + βEQEQ}

Where, N = group number, = load factor, β = coefficient,



D = dead load; L = live load; I = live load impact; E = earth pressure; B = buoyancy; W = wind load on structure; WL = wind load on live load --- 1.46 kN/m; LF = longitudinal force from live load; CF = centrifugal force; R = rib shortening; S = shrinkage; T = temperature; EQ = earthquake; SF = stream flow pressure;

TABLE OF COEFFICIENTS AND β COL. No. 1 2 3 3A 4 5 6 7 8 9 10 11 12 13

β FACTORS

GROUP � D ( L +

I)n ( L +

I)n CF E B SF W WL LF R + S + T EQ %

SE

RV

ICE

LO

AD

I 1.0 1 1 0 1 βE 1 1 0 0 0 0 0 100IA 1.0 1 2 0 0 O 0 0 0 0 0 0 0 150IB 1.0 1 0 1 1 βE 1 1 0 0 0 0 0 **

Culverts

II 1.0 1 0 0 0 1 1 1 1 0 0 0 0 125III 1.0 1 1 0 1 βE 1 1 0.3 1 1 0 0 125IV 1.0 1 1 0 1 βE 1 1 0 0 0 1 0 125V 1.0 1 0 0 0 1 1 1 1 0 0 1 0 140VI 1.0 1 1 0 1 βE 1 1 0.3 1 1 1 0 140VII 1.0 1 0 0 0 1 1 1 0 0 0 0 1 133VIII 1.0 1 1 0 1 1 1 1 0 0 0 0 0 140IX 1.0 1 0 0 0 1 1 1 1 0 0 0 0 150X 1.0 1 1 0 0 βE 0 0 0 0 0 0 0 100



TABLE OF COEFFICIENTS AND β

For seismic design of structural member, loading combination VII shall be modified as per section 5.1.2 of the design criteria. 7.0 DEFLECTION 7.1 Members having simple or continuous spans preferably should be

designed so that the deflection due to service live load plus impact shall not exceed 1/800 of the span, except on bridges in urban areas used in part by pedestrians whereon the ratio preferably shall not exceed 1/1000. For checking deflection, the service live load preferably shall not exceed HS 20 Loading.

7.2 The deflection of cantilever arms due to service live load plus impact preferably should be limited to 1/300 of the cantilever arm except for the case including pedestrian use, where the ratio preferably should be 1/375.

8.0 FOUNDATIONS

The foundation shall be designed based on the allowable bearing capacity of bored piles/ driven piles recommended in the Geotechnical Investigation Report conducted by A. M. Geoconsult & Associates dated January 21, 2013.

COL. No. 1 2 3 3A 4 5 6 7 8 9 10 11 12 13

Culverts

β FACTORS

GROUP � D ( L +

I)n ( L +

I)n CF E B SF W WL LF R + S + T EQ %

LO

AD

FA

CT

OR

DE

SIG

N

I 1.3 βD 1.67* 0 1.0 βE 1 1 0 0 0 0 0

Not

App

lica

ble

IA 1.3 βD 2.20 0 0 O 0 0 0 0 0 0 0

IB 1.3 βD 0 1 1.0 βE 1 1 0 0 0 0 0

II 1.3 βD 0 0 0 βE 1 1 1 0 0 0 0

III 1.3 βD 1 0 1 βE 1 1 0.3 1 1 0 0

IV 1.3 βD 1 0 1 βE 1 1 0 0 0 1 0

V 1.25 βD 0 0 0 βE 1 1 1 0 0 1 0

VI 1.25 βD 1 0 1 βE 1 1 0.3 1 1 1 0

VII 1.3 βD 0 0 0 βE 1 1 0 0 0 0 1

VIII 1.3 βD 1 0 1 βE 1 1 0 0 0 0 0

IX 1.20 βD 0 0 0 βE 1 1 1 0 0 0 0 X 1.30 1 1.67 0 0 βE 0 0 0 0 0 0 0 100



9.0 ALLOWABLE STRESSES FOR ALLOWABLE STRESS DESIGN

9.1 Allowable Stresses for Steel

A. Allowable Tensile Stress On gross section FyFt 55.0 On net section FuFt 50.0

B. Allowable Axial Compressive Stress

When r

kl ≤ Cc

E

Fyr

kl

FS

FyFa

2

2

41

When r

kl > Cc

2

2

r

klFS

EFa

Where,

Cc = Fy

E22

FS = 2.12

C. Allowable Compressive Bending Stress

When compression flange is supported laterally in its full length by embedment in concrete,

FyFb 55.0

When compression flange is partially supported or is unsupported,

2

87.9772.0344750

d

I

JI

S

CFb

yc

yc

xc

b Fy55.0

Where,

Cb = 3.23.005.175.12

2

1

2

1

M

M

M

M



2

1

M

M = positive when moments cause reverse curvature

2

1

M

M = negative when bent is in single curvature.

Cb = 1.0 for unbraced cantilevers and for member

when the moment within a significant point of the unbraced segment is greater than or equal to the larger of the segment end moments.

= length in meters

ycI = moment of inertia of compression flange about

the vertical axis in the plane of the web, mm4 d = depth of girder, mm

J =

3

333 Dtwbtbt tc ,where b and t

represent the flange thickness of the compression and tension flange, respectively (mm4)

xcS = section modulus with respect to compression

flange, mm3 E = modulus of elasticity of steel r = governing radius of gyration L = actual unbraced length k = effective length factor FS = 2.12

D. Allowable Shear Stress

Shear in girder, webs, gross section FyFv 33.0

E. Combined Stresses

1. Axial Compression and Bending Stresses

a. At intermediate points

0.1

'1

'1

yy

ymy

xx

xmx

FbFe

fa

FbC

FbFe

fa

fbC

Fa

fa

b. At point of supports (points braced in the plane of bending 5

0.1472.0

y

y

x

x

Fb

Fb

Fb

fb

Fy

fa



Where,

Fe’ = 2

2

b

bb

r

LkFS

E

fa = computed axial stress fbx of fby = computed compressive bending

stress about the x-axis and y-axis, respectively

Fa = axial stress that would be permitted if axial force alone existed, regardless of the plane of bending

Fbx, Fby = compressive bending stress that would be permitted if bending moment alone existed about the x-axis and the y-axis respectively evaluated according to AASHTO Table 10.32.1A

Fe’ = Euler Buckling stress divided by a factor of safety

E = modulus of elasticity of steel kb = effective length factor in the plane of

bending (see AASHTO Appendix C) Lb = actual unbraced length in the plane of

bending rb = radius of gyration Cmx, Cmy = coefficient about the x-axis and the y-

axis, respectively, whose value is taken from AASHTO Table 10.36A

FS = 2.12

2. Axial Tension and Bending Stress a. At intermediate points

0.1y

y

x

x

Fb

Fb

Fb

fb

Ft

ft

b. At point of supports (points braced in the plane of bending

0.1472.0

y

y

x

x

Fb

Fb

Fb

fb

Fy

ft

DESIGN

CALCULATIONS

Design of Box Culvert with Seismic Design Code

Backfill Slope Angle i = 0 (deg)

Angle of Friction of Soil Φ = 30 (deg)

Height of Soil Face H = 7.6 m

Total Span of Box Culvert Bridge S= 14 m

Total Width of Box Culvert Bridge W= 10.2 m

Tributary Width considered in analysis tW = 10.2 m

Acceleration Coefficient a = 0.4

Unit Weight of Soil γsoil = 18 kN/m3

δst = 17 (Static Condition)

δse = 8.5 (Seismic Condition)

Horizontal Seismic Coefficient kh = 1/2 a = 0.2

Vertical Seismic Coefficient kv: 0.3kh < kv < 0.5 kh

0.06 < kv < 0.10 thus, use

kv = 0.08

Seismic Internal Angle θ = arc tan (kh / (1-kv))θ = 12.265 (deg)

Slope of Soil Face β = 0 (deg)radian = 0.0175

K 0 4459

Compute Seismic Active Earth Pressure Using the Mononobe-Okabe Equation

Angle of Friction between Soil and Abutment

Seismic Active Earth Pressure KAE = 0.4459

Seismic Active Earth Pressure PAE = 1/2 (γsoil) (H)2 (1-KV) (KAE)

PAE = 213.25 kN /m

KA= 0.2994

Static Active Earth Pressure PA= 155.66 kN /m

Concentrated force of PA= 1587.7 kN (Applied at 1/3*H)

Thrust factor, Ft = [PA(H/3) + (PAE - PA)(0.6)H] / [PA(H1.6659

Ft (PA) = 259.31 kN/m

Dynamic Earth Pressure, EQL= 2645 kN (Applied at 0.6H)

Seismic Active Earth Pressure Coefficient

Static Active Earth Pressure Coefficient

Compute Equivalent Pressure Determine a single equivalent pressure: Static pressure acting at H/3 & Seismic pressure at 6/10 of H

DESIGN OF BOX CULVERT TYPE CASTELLANO BRIDGE1.0 FIGURE

2.0 LOADINGS 2.1 DEAD LOAD

a. Selfweightb. Wearing Surface c. Sidewalks/Curbsd. Railings

2.2 LIVE LOADa. Truck Load MS 18 (HS20-44) & Equivalent Lane Loadingb. Permit design live load

Sid lk 2870 kPc. Sidewalk 2870 kPa IMPACT FORMULA

I = 15.24 / (S + 38) I = impact fraction, maximum 30 percent

I = 0.2932.3 EARTH'S PRESSURE

a. Static Earth's Pressureb. Dynamic Earth's Pressure (Mononobe-Okabe)

3.0 MATERIALS 3.1 CONCRETE

Unit Wt.of Concrete = 24 kN/m3Compressive strength, f'c = 27.6 MpaModulus Of Elasticity = 27336 Mpa

3.2 STEELYield Strength Bars = 414 MpaModulus Of Elasticity = 200000 Mpa

4.0 DESIGN MOMENTS (Kn-m)

B C D E F G I J Des Moment Des Axial-2690 2760 2760 575 -1611 2195 2195 -1295 154 2183

-802 661 662 276 -110 33 33 33 49 160-604 414 414 173 -69 21 21 21 31 181-137 122 122 51 -20 6 6 6 9 37161 161 161 -499 199 74 74 74 111 0355 355 355 -1020 323 -101 -101 -101 151 0

-2827 2882 2882 626 -1631 2201 2201 -1289 163 2220-802 661 662 276 -110 33 33 33 49 181-137 122 122 51 -20 6 6 6 9 37355 355 355 -1020 323 -101 -101 -101 151 0

4.1 LOAD COMBINATION

GROUP g βD(L+I)n E A B C D E F G I J Des Moment Des AxialI 1.3 1 1.7 1.3 4926 -3764 4925 4926 -668 -1670 2720 2720 -1817 510 3049

IA 1.3 1 2.2 0 4460 -4526 4459 4460 1111 -2239 2897 2897 -1640 265 3086IB 1.3 1 0 1.3 4505 -3254 4505 4505 -844 -1600 2699 2699 -1838 479 2934II 1.3 1 0 1.3 4505 -3254 4505 4505 -844 -1600 2699 2699 -1838 479 2934III 1.3 1 1 1.3 4757 -3559 4757 4757 -739 -1642 2712 2712 -1825 497 3003IV 1.3 1 1 1.3 4757 -3559 4757 4757 -739 -1642 2712 2712 -1825 497 3003V 1.3 1 0 1.3 4332 -3128 4332 4332 -811 -1539 2595 2595 -1767 460 2821VI 1.3 1 1 1.3 4574 -3422 4574 4574 -710 -1579 2607 2607 -1755 478 2887VII 1.3 1 0 1.3 4505 -3254 4505 4505 -844 -1600 2699 2699 -1838 479 2934VIII 1.3 1 1 1.3 4757 -3559 4757 4757 -739 -1642 2712 2712 -1825 497 3003IX 1.2 1 0 1.3 4158 -3003 4158 4158 -779 -1477 2491 2491 -1697 442 2709X 1.2 1 1.7 1.3 4547 -3474 4547 4547 -617 -1542 2511 2511 -1677 471 2815

4926 -4526 4925 4926 1111 -2239 2897 2897 -1838 510 3086

4.2 FLEXURAL REINFORCEMENT

Pile Head

Pile Head

DEAD LOADTRUCK LOADLANE LOADS

SIDEWALK 122EARTH'S

DYNAMIC

A2760

355

SIDEWALKSTATIC

662414122161

DEAD LOAD 2882LIVE LOAD 662

355

Design Data:Bridge width 10200 mm db= 28 mm db= 20 mm

Bridge Span As= 615.8 mm2 As= 314.2 mm2

Clear cover 50 mmt1= 700 mm db= 25 mm

t2= 900 mm tmid= 800 mm As= 490.9 mm2

t3= 600 mmfooting= 1500 mm

Mu d w ρreqd ρdesign As4926 811 0.0301 0.002 0.0032 264714526 711 0.0361 0.0024 0.0032 232074925 811 0.0301 0.002 0.0032 264714926 611 0.0538 0.0036 0.0036 223471111 611 0.0118 0.0008 0.0032 199432239 611 0.024 0.0016 0.0032 199432897 486 0.0499 0.0033 0.0033 164822897 486 0.0499 0.0033 0.0033 164821838 486 0.0313 0.0021 0.0032 15863

4.3 TEMPERATURE REINFORCEMENT

As Asb1620 490.91440 490.92700 490.91260 490.91260 490.91260 490.92700 490.92700 490.91080 490.9

5.0 DESIGN SHEAR (Kn)

B C D E F G I J Des Moment Des ShearPile Head

28mmφ @ 20028mmφ @ 200

bw=

Section SpacingAB

28mmφ @ 20028mmφ @ 20028mmφ @ 200

DEFGIJ

28mmφ @ 200

28mmφ @ 20028mmφ @ 20028mmφ @ 200

Section

C

cc=

As SpacingABC

0.0018bt0.0018bt0.0018bt

25mmφ @ 150

DEFGIJ

0.0018bt0.0018bt0.0018bt0.0018bt0.0018bt0.0018bt

25mmφ @ 19025mmφ @ 200

25mmφ @ 15025mmφ @ 15025mmφ @ 19025mmφ @ 19025mmφ @ 19025mmφ @ 190

A3 -1556 -659 -659 -659 845 846 0 154 -30

36 -320 -27 -27 -27 0 0 0 49 780 -131 -41 -41 -41 -1 -1 -1 31 6

0 -74 -23 -23 -23 0 0 0 9 10 0 -216 -216 451 0 0 0 111 -400 0 -673 440 440 0 0 0 151 -59

3 -1630 -682 -682 -682 845 846 0 163 -2980 -320 -41 -41 -41 -1 -1 -1 49 7

0 -74 -23 -23 -23 0 0 0 9 10 0 -673 440 451 0 0 0 151 -59

DEAD LOAD 1556TRUCK LOAD 320LANE LOADS 362SIDEWALK 74STATIC 0DYNAMIC 0TRANSV

DEAD LOAD 1630LIVE LOAD 362SIDEWALK 74EARTH'S 0TRANSV

5.1 LOAD COMBINATION

GROUP g βD(L+I)n E A B C D E F G I J Des Moment Des ShearI 1.3 1 1.7 1.3 2446 55 -2419 -2081 -201 -181 1098 1099 0 510 -132

IA 1.3 1 2.2 0 2519 71 -2484 -952 -952 -952 1098 1099 -1 265 -31IB 1.3 1 0 1.3 2215 4 -2215 -2054 -174 -155 1099 1100 0 479 -137II 1.3 1 0 1.3 2215 4 -2215 -2054 -174 -155 1099 1100 0 479 -137III 1.3 1 1 1.3 2353 35 -2337 -2070 -190 -170 1098 1100 0 497 -134IV 1.3 1 1 1.3 2353 35 -2337 -2070 -190 -170 1098 1100 0 497 -134V 1.3 1 0 1.3 2130 4 -2130 -1975 -168 -149 1056 1058 0 460 -131VI 1.3 1 1 1.3 2263 33 -2247 -1990 -183 -164 1056 1057 0 478 -129VII 1.3 1 0 1.3 2215 4 -2215 -2054 -174 -155 1099 1100 0 479 -137VIII 1.3 1 1 1.3 2353 35 -2337 -2070 -190 -170 1098 1100 0 497 -134IX 1.2 1 0 1.3 2045 4 -2045 -1896 -161 -143 1014 1015 0 442 -126X 1.2 1 1.7 1.3 2257 51 -2233 -1921 -185 -167 1014 1015 0 471 -122

2519 71 -2484 -2081 -952 -952 1099 1100 0 510 -31

5.2 CHECK SHEARVu=ΦVn φ=0.85Vn=Vc+Vs

Vc=1 / 6 (√f'c)(bw)(d)Vu bw d Vn Vc2519 10200 811 2963 38052

71 10200 711 83.989 333602484 10200 811 2921.9 380522081 10200 611 2447.8 28668

952 10200 611 1120.2 28668952 10200 611 1120.2 28668

1099 10200 486 1292.4 228031100 10200 486 1293.9 22803

0 10200 486 0 22803

Pile Head

SectionAB

FGI Ok

CDE

OkJ

OkOk

REMARK

OkOkOkOkOk

Documents

Design of box culvert bridge