DESIGN CRITERIA
Structural Design Criteria of the Proposed
CASTELLANO BRIDGE
1.0
MAY 2013
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
2.2
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.
Material Codes and Standards 2.2.1 American Society for Testing Materials (ASTM).
Structural Design of the Proposed
CASTELLANO BRIDGE
3.0
MAY 2013
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
Structural Design of the Proposed
CASTELLANO BRIDGE
4.0
MAY 2013
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 Box Culvert Bored Pile Sidewalk, railings, parapet, median Other concrete Lean concrete Non Shrink Grout
4.2
f’c 28.0 MPa (4,000 Psi) 21.0 MPa (3,000 Psi) 21.0 MPa (3,000 Psi) 21.0 MPa (3,000 Psi) 17.0 MPa (2,400 Psi) 58.0MPa (8,000Psi)
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 threedimensional 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
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
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 B SF E
= = = =
dead load buoyancy stream flow pressure earth pressure
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
EQM or EQF =
5.2
elastic seismic force for either Load Case I or Load Case 2 modified by dividing the appropriate R-Factor
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 Concrete, plain or reinforced Compacted earth, sand, gravel, or ballast Structural Steel Cast Iron Water (without sediment) Bituminous wearing surface (50 mm thk) 6.2
Unit Weight (kN/m3) 24 18.9 77 71 9.81 1.05 kPa
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
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
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.
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
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
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
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:
I Where, I = L =
6.3
15.24 L 38 impact factor (maximum of 30 percent) length in meters of the portion of the span that is loaded to produce the maximum stress in the member
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
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
43,800 16.7 W P 1,435 L 15.2 In which P L W
= = =
live load in Pa. max. 2870 Pa. loaded length of sidewalk in meters 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.
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
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
0.29 <
A A A
≤ 0.29
Importance Classification (IC) I II C C 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:
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
S
Soil Profile Type I II III 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 Reinforced Concrete Pile Bents
2
Superstructure to Abutment
0.8
a. Vertical Piles only b. One or more Batter Piles
3
Expansion Joints within a Span
2
Single Columns
3
of the Superstructure Columns, Piers or Pile Bents to Cap Beam or Superstructure3 Columns or Piers to Foundations3
0.8
Steel or Composite Steel and 1.0 Concrete Pile Bents a. Vertical Piles only 5 1.0 b. One or more Batter Piles 3 Multiple Column Bent 5 1 The R-Factor is to be used for both orthogonal axes of the substructure. 2 A 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
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
Lateral earth pressures shall be computed assuming active stress conditions and wedge theory using a planar surface of sliding defined by Coulomb’s Theory.
ka
sin 2 ( ' ) sin( ' ) sin( ' ) sin 2 sin( ) 1 sin( ) sin( )
Where, ka
= = = = = =
’ ’ β
active earth pressure coefficient effective unit weight effective angle of internal friction angle of wall friction 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. kae
cos 2 ( ) cos cos 2 cos( )
Where, kae
=
H
= =
total Mononobe-Okabe seismic lateral earth pressure coefficient height of soil face unit weight of soil
Structural Design of the Proposed
CASTELLANO BRIDGE
β kh kv
MAY 2013
= = = = = =
angle of friction of soil arc tan (kh /1-kv) angle of friction between soil and abutment backfill slope angle horizontal acceleration coefficient vertical acceleration coefficient
=
sin( ) sin( i ) 1 cos( ) cos(i )
6.5.2 Earth Load 1 Pa k a H 2 2 1 Pa k ae (1 k v )H 2 2 6.6
2
for normal condition for seismic condition
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 = = β =
group number, load factor, coefficient,
Structural Design of the Proposed
CASTELLANO BRIDGE
D L I E B W WL LF CF R S T EQ SF
MAY 2013
= = = = = = = = = = = = = =
dead load; live load; live load impact; earth pressure; buoyancy; wind load on structure; wind load on live load --- 1.46 kN/m; longitudinal force from live load; centrifugal force; rib shortening; shrinkage; temperature; earthquake; stream flow pressure;
TABLE OF COEFFICIENTS AND β COL. No.
SERVICE LOAD
GROUP I IA IB II III IV V VI VII VIII IX X
1
1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
2
3
3A
D 1 1 1 1 1 1 1 1 1 1 1 1
(L+ I)n 1 2 0 0 1 1 0 1 0 1 0 1
(L+ I)n 0 0 1 0 0 0 0 0 0 0 0 0
4
CF 1 0 1 0 1 1 0 1 0 1 0 0
5
E βE O βE 1 βE βE 1 βE 1 1 1 βE
6 7 8 β FACTORS
9
10
B SF W WL LF 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 1 1 1 0 0 1 1 0.3 1 1 1 1 0 0 0 1 1 1 0 0 1 1 0.3 1 1 1 1 0 0 0 1 1 0 0 0 1 1 1 0 0 0 0 0 0 0
11
12
13
R+S +T 0 0 0 0 0 1 1 1 0 0 0 0
EQ 0 0 0 0 0 0 0 0 1 0 0 0
% 100 150 ** 125 125 125 140 140 133 140 150 100 Culverts
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
TABLE OF COEFFICIENTS AND β 1
LOAD FACTOR DESIGN
GROUP
2
D
3 (L+ I)n
3A
4
(L+ I)n
5
CF
I
1.3
βD 1.67*
0
IA
1.3
βD
2.20
0
IB
1.3
βD
0
1
II
1.3
βD
0
0
0
III
1.3
βD
1
0
IV
1.3
βD
1
V
1.25 βD
VI
6 7 8 β FACTORS
E
B SF
10 11
WL LF
12
13
R+S +T
EQ
1
0
0
0
0
0
0
0
0
0
0
0
0
1.0 βE 1
1
0
0
0
0
0
βE 1
1
1
0
0
0
0
1
βE 1
1
0.3
1
1
0
0
0
1
βE 1
1
0
0
0
1
0
0
0
0
βE 1
1
1
0
0
1
0
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
0 1.67
0 0
0 0
βE 1 βE 0
1 0
1 0
0 0
0 0
0 0
0 0
IX X
1.20 βD 1.30 1
1.0 βE 1
W
9
0
O
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.
%
Not Applicable
COL. No.
100
Culverts
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
9.0 ALLOWABLE STRESSES FOR ALLOWABLE STRESS DESIGN
9.1 Allowable Stresses for Steel A. Allowable Tensile Stress
Ft 0.55Fy Ft 0.50 Fu
On gross section On net section
B. Allowable Axial Compressive Stress
When
kl ≤ Cc r
When
kl > Cc r
kl 2 Fy Fy r Fa 1 FS 4 2 E 2 E Fa 2 kl FS r
Where, Cc
=
FS
=
2 2 E Fy 2.12
C. Allowable Compressive Bending Stress When compression flange is supported laterally in its full length by embedment in concrete, Fb 0.55Fy
When compression flange is partially supported or is unsupported, 344750C b Fb S xc
I yc
0.772 J d 9.87 I yc
2
0 . 55 Fy
Where, Cb
=
M1 M 0 . 3 1 1 . 75 1 . 05 M2 M2
2
2 . 3
Structural Design of the Proposed
CASTELLANO BRIDGE
M1 M 2 M1 M 2
MAY 2013
=
positive when moments cause reverse curvature
=
negative when bent is in single curvature.
Cb
=
I yc
= =
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 moment of inertia of compression flange about
d
=
J
=
S xc
=
E r L k FS
= = = = =
the vertical axis in the plane of the web, mm4 depth of girder, mm bt 3 c bt 3 t Dtw 3 ,where b and t 3 represent the flange thickness of the compression and tension flange, respectively (mm4) section modulus with respect to compression flange, mm3 modulus of elasticity of steel governing radius of gyration actual unbraced length effective length factor 2.12
D. Allowable Shear Stress Shear in girder, webs, gross section
Fv 0.33Fy
E. Combined Stresses 1. Axial Compression and Bending Stresses a. At intermediate points C my Fb y C mx fbx fa 1.0 Fa fa fa Fb 1 Fbx 1 Fe' y Fe' x y b. At point of supports (points braced in the plane of bending 5 Fb y fb fa x 1.0 0.472 Fy Fbx Fb y
Structural Design of the Proposed
CASTELLANO BRIDGE
MAY 2013
Where, Fe’
=
fa fbx of fby
= =
Fa
=
Fbx, Fby
=
Fe’
=
E kb
= =
Lb
=
rb Cmx, Cmy
= =
FS
=
2E 2
k L FS b b rb computed axial stress computed compressive bending stress about the x-axis and y-axis, respectively axial stress that would be permitted if axial force alone existed, regardless of the plane of bending 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 Euler Buckling stress divided by a factor of safety modulus of elasticity of steel effective length factor in the plane of bending (see AASHTO Appendix C) actual unbraced length in the plane of bending radius of gyration coefficient about the x-axis and the yaxis, respectively, whose value is taken from AASHTO Table 10.36A 2.12
2. Axial Tension and Bending Stress a. At intermediate points ft fbx Fb y 1.0 Ft Fbx Fb y b. At point of supports (points braced in the plane of bending Fb y fb ft x 1.0 0.472 Fy Fbx Fb y
DESIGN CALCULATIONS
Design of Box Culvert with Seismic Design Code Compute Seismic Active Earth Pressure Using the Mononobe-Okabe Equation 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=
Unit Weight of Soil
γsoil =
Angle of Friction between Soil and Abutment Horizontal Seismic Coefficient
0.4 3
18 kN/m
δst =
17 (Static Condition)
δse =
8.5 (Seismic Condition)
kh = 1/2 a =
0.2
Vertical Seismic Coefficient kv: 0.3kh < kv < 0.5 kh 0.06 < kv < 0.10 kv = 0.08 Seismic Internal Angle
thus, use
θ = arc tan (kh / (1-kv)) θ = 12.265 (deg)
Slope of Soil Face
β= 0 (deg) radian = 0.0175
Seismic Active Earth Pressure Coefficient
KAE = 0.4459 0 4459
2
PAE = 1/2 (γsoil) (H) (1-KV) (KAE)
Seismic Active Earth Pressure
PAE = 213.25 kN /m Static Active Earth Pressure Coefficient
KA= 0.2994
Static Active Earth Pressure
PA= 155.66 kN /m
Concentrated force of PA= 1587.7 kN (Applied at 1/3*H) Compute Equivalent Pressure Determine a single equivalent pressure: Static pressure acting at H/3 & Seismic pressure at 6/10 of H Thrust factor,
Ft = [PA(H/3) + (PAE - PA)(0.6)H] / [PA(H 1.6659 Ft (PA) = 259.31 kN/m
Dynamic Earth Pressure,
EQL=
2645 kN (Applied at 0.6H)
DESIGN OF BOX CULVERT TYPE CASTELLANO BRIDGE 1.0 FIGURE
2.0 LOADINGS 2.1 DEAD LOAD a. Selfweight b. Wearing Surface c. Sidewalks/Curbs d. Railings 2.2 LIVE LOAD a. Truck Load MS 18 (HS20-44) & Equivalent Lane Loading b. Permit design live load c. Sidewalk Sid lk 2870 kP kPa IMPACT FORMULA I = 15.24 / (S + 38) I = impact fraction, maximum 30 percent I = 0.293 2.3 EARTH'S PRESSURE a. Static Earth's Pressure b. Dynamic Earth's Pressure (Mononobe-Okabe) 3.0 MATERIALS 3.1 CONCRETE Unit Wt.of Concrete = Compressive strength, f'c = Modulus Of Elasticity = 3.2 STEEL Yield Strength Bars = Modulus Of Elasticity =
24 kN/m3 27.6 Mpa 27336 Mpa 414 Mpa 200000 Mpa
4.0 DESIGN MOMENTS (Kn-m)
DEAD LOAD TRUCK LOAD LANE LOADS SIDEWALK STATIC DYNAMIC
A 2760 662 414 122 161 355
B -2690 -802 -604 -137 161 355
C 2760 661 414 122 161 355
D 2760 662 414 122 161 355
E 575 276 173 51 -499 -1020
F -1611 -110 -69 -20 199 323
G 2195 33 21 6 74 -101
I 2195 33 21 6 74 -101
Pile Head Des Moment Des Axial J -1295 154 2183 33 49 160 21 31 181 6 9 37 74 111 0 -101 151 0
DEAD LOAD LIVE LOAD SIDEWALK EARTH'S
2882 662 122 355
-2827 -802 -137 355
2882 661 122 355
2882 662 122 355
626 276 51 -1020
-1631 -110 -20 323
2201 33 6 -101
2201 33 6 -101
-1289 33 6 -101
A 4926 4460 4505 4505 4757 4757 4332 4574 4505 4757 4158 4547 4926
B -3764 -4526 -3254 -3254 -3559 -3559 -3128 -3422 -3254 -3559 -3003 -3474 -4526
C 4925 4459 4505 4505 4757 4757 4332 4574 4505 4757 4158 4547 4925
D 4926 4460 4505 4505 4757 4757 4332 4574 4505 4757 4158 4547 4926
E -668 1111 -844 -844 -739 -739 -811 -710 -844 -739 -779 -617 1111
F -1670 -2239 -1600 -1600 -1642 -1642 -1539 -1579 -1600 -1642 -1477 -1542 -2239
G 2720 2897 2699 2699 2712 2712 2595 2607 2699 2712 2491 2511 2897
I 2720 2897 2699 2699 2712 2712 2595 2607 2699 2712 2491 2511 2897
163 49 9 151
2220 181 37 0
4.1 LOAD COMBINATION GROUP I IA IB II III IV V VI VII VIII IX X
g βD(L+I)n E 1.3 1 1.7 1.3 1.3 1 2.2 0 1.3 1 0 1.3 1.3 1 0 1.3 1.3 1 1 1.3 1.3 1 1 1.3 1.3 1 0 1.3 1.3 1 1 1.3 1.3 1 0 1.3 1.3 1 1 1.3 1.2 1 0 1.3 1.2 1 1.7 1.3
4.2 FLEXURAL REINFORCEMENT
J -1817 -1640 -1838 -1838 -1825 -1825 -1767 -1755 -1838 -1825 -1697 -1677 -1838
Pile Head Des Moment Des Axial 510 3049 265 3086 479 2934 479 2934 497 3003 497 3003 460 2821 478 2887 479 2934 497 3003 442 2709 471 2815 510 3086
Bridge width Bridge Span Clear cover
Design Data: bw= 10200 mm cc= t1= t2= t3= footing=
50 700 900 600 1500
Section A B C D E F G I J
Mu 4926 4526 4925 4926 1111 2239 2897 2897 1838
db= As=
mm mm mm mm mm d 811 711 811 611 611 611 486 486 486
tmid=
w 0.0301 0.0361 0.0301 0.0538 0.0118 0.024 0.0499 0.0499 0.0313
28 mm 2 615.8 mm
db= As=
20 mm 2 314.2 mm
800 mm
db= As=
25 mm 2 490.9 mm
ρreqd ρdesign 0.002 0.0032 0.0024 0.0032 0.002 0.0032 0.0036 0.0036 0.0008 0.0032 0.0016 0.0032 0.0033 0.0033 0.0033 0.0033 0.0021 0.0032
As 26471 23207 26471 22347 19943 19943 16482 16482 15863
28mmφ @ 28mmφ @ 28mmφ @ 28mmφ @ 28mmφ @ 28mmφ @ 28mmφ @ 28mmφ @ 28mmφ @
Spacing 200 200 200 200 200 200 200 200 200
4.3 TEMPERATURE REINFORCEMENT Section A B C D E F G I J
As 0.0018bt 0.0018bt 0.0018bt 0.0018bt 0.0018bt 0.0018bt 0.0018bt 0.0018bt 0.0018bt
As 1620 1440 2700 1260 1260 1260 2700 2700 1080
Asb 490.9 490.9 490.9 490.9 490.9 490.9 490.9 490.9 490.9
Spacing 25mmφ @ 150 25mmφ @ 150 25mmφ @ 150 25mmφ @ 190 25mmφ @ 190 25mmφ @ 190 25mmφ @ 190 25mmφ @ 190 25mmφ @ 200
B 3 36 80 0 0 0
C -1556 -320 -131 -74 0 0
D -659 -27 -41 -23 -216 -673
E -659 -27 -41 -23 -216 440
F -659 -27 -41 -23 451 440
G 845 0 -1 0 0 0
I 846 0 -1 0 0 0
3 80 0 0
-1630 -320 -74 0
-682 -41 -23 -673
-682 -41 -23 440
-682 -41 -23 451
845 -1 0 0
846 -1 0 0
5.0 DESIGN SHEAR (Kn)
DEAD LOAD TRUCK LOAD LANE LOADS SIDEWALK STATIC DYNAMIC TRANSV DEAD LOAD LIVE LOAD SIDEWALK EARTH'S TRANSV
A 1556 320 362 74 0 0
1630 362 74 0
J 0 0 -1 0 0 0
0 -1 0 0
Pile Head Des Moment Des Shear 154 -30 49 7 31 6 9 1 111 -40 151 -59
163 49 9 151
-29 7 1 -59
5.1 LOAD COMBINATION GROUP I IA IB II III IV V VI VII VIII IX X
g βD(L+I)n E 1.3 1 1.7 1.3 1.3 1 2.2 0 1.3 1 0 1.3 1.3 1 0 1.3 1.3 1 1 1.3 1.3 1 1 1.3 1.3 1 0 1.3 1.3 1 1 1.3 1.3 1 0 1.3 1.3 1 1 1.3 1.2 1 0 1.3 1.2 1 1.7 1.3
A 2446 2519 2215 2215 2353 2353 2130 2263 2215 2353 2045 2257 2519
5.2 CHECK SHEAR Vu=ΦVn Vn=Vc+Vs Section A B C D E F G I J
B 55 71 4 4 35 35 4 33 4 35 4 51 71
C -2419 -2484 -2215 -2215 -2337 -2337 -2130 -2247 -2215 -2337 -2045 -2233 -2484
D -2081 -952 -2054 -2054 -2070 -2070 -1975 -1990 -2054 -2070 -1896 -1921 -2081
E -201 -952 -174 -174 -190 -190 -168 -183 -174 -190 -161 -185 -952
F -181 -952 -155 -155 -170 -170 -149 -164 -155 -170 -143 -167 -952
G 1098 1098 1099 1099 1098 1098 1056 1056 1099 1098 1014 1014 1099
I 1099 1099 1100 1100 1100 1100 1058 1057 1100 1100 1015 1015 1100
φ=0.85
Vu 2519 71 2484 2081 952 952 1099 1100 0
Vc=1 / 6 (√f'c)(bw)(d) bw d Vn 10200 811 2963 10200 711 83.989 10200 811 2921.9 10200 611 2447.8 10200 611 1120.2 10200 611 1120.2 10200 486 1292.4 10200 486 1293.9 10200 486 0
Vc 38052 33360 38052 28668 28668 28668 22803 22803 22803
REMARK Ok Ok Ok Ok Ok Ok Ok Ok Ok
J 0 -1 0 0 0 0 0 0 0 0 0 0 0
Pile Head Des Moment Des Shear 510 265 479 479 497 497 460 478 479 497 442 471 510
-132 -31 -137 -137 -134 -134 -131 -129 -137 -134 -126 -122 -31
