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Industry Standard of the People's Republic of China
The Standard of Loadings for the Municipal Bridge Design
CJJ 77--98
Editing Unit: Urban Construction Research Institute of the Ministry of ConstructionApproving Department: Ministry of Construction of the People's Republic of ChinaEffective Date: December 1, 1998
4-19-1
Notice on Issuing Industry Standard
"Standard for Design Loads of Urban Bridges" [Jianbiao 1998] No. 125
According to the requirements of the Ministry of Construction's "Notice on Printing and Distributing the 1988 Project Plan for the Preparation and Revision of Standards, Specifications and Regulations of the Ministry of Urban and Rural Construction and Environmental Protection" (88) Chengbiao No. 141, the "Standard for Design Loads of Urban Bridges" edited by the Urban Construction Research Institute of the Ministry of Construction has been reviewed and approved as a mandatory industry standard, numbered CJJ77--98, and will be implemented on December 1, 1998.
This standard is managed by the Ministry of Construction's Urban Road and Bridge Standard Technical Management Unit 4—19-2
Beijing Municipal Engineering Design and Research Institute, and the Ministry of Construction's Urban Construction Research Institute is responsible for the specific interpretation. This standard is published by the Ministry of Construction's Standard and Quota Research Institute and China Building Industry Press.
Ministry of Construction of the People's Republic of China
June 9, 1998
2 Terms and symbols
2.2 Symbols
3 Urban bridge design loads
Load classification...
Load combination·
中+--
营营事
-19—4
4—19—4
4—19—4
... 4—19.-4
-19—4
.. 4—19—4
-19—5
3.3 Permanent load
3.4 Occasional load
.........
Variable load for urban bridge design
4—19-5
4—19—6
:4—19—6
Basic variable load
**++*..... 4-196
.2 Other variable loads…·
Appendix A Explanation of terms used in this standard
Additional explanation
............. 4-198
............... 4-198
4—19-3
In order to improve the current method of urban bridge design load determination, the uniformly distributed load according to lanes is adopted. 1. 0. 1
This standard is formulated for the purpose of increasing the design of bridge loads to meet the international standards for bridge loads.
1.0.2 This standard is applicable to the design of permanent bridges and urban elevated road structures newly built or rebuilt in Singapore, as well as other structures subject to motor vehicle loads. 1.0.3 The basic variable loads specified in this standard are applicable to urban bridge structures with a span or loading length of no more than 150m.
1.0.4 The design loads in this standard are divided into two levels, urban-A and urban-B.
In addition to complying with this standard, the design loads of urban bridges shall also comply with the provisions of the relevant national standards in force.
2 Terms and symbols
2.1.1 Action
A general term for the force effect caused by various loads and deformations borne by the structure. 2.1.2 Loads
Gravity caused by various vehicles, people, snow, and wind, including permanent, variable, and accidental loads.
Z.1.3 Permanent Loads Loads whose values do not change with time during the design validity period, or whose changes are negligible compared to the average value.
2. 1. 4 Variable Loads Loads whose values change with time during the design validity period, and whose changes are not negligible compared to the average value. According to their influence on the bridge structure, they can be divided into basic variable loads (active loads) and other variable loads. 2. 1.5 Accidental Loads Loads that may not appear during the design validity period, but once they appear, their values will be very large and last for a very short time.
f Ultimate Limit State Design2. 1. 6
Ultimate Limit State Design
When the structure reaches the ultimate state of its bearing capacity. The design method is used when the effect caused by the structure is equal to the resistance of the material. Z.1.7 Serviceability Limit State Design
The design method when the crack chain, stress and resistance of the structure reach the maximum during the normal working stage.
Allowable Stress Design
Allowable Stress Design
The design method when the cross-section of various materials reaches the allowable stress. 2.1.9 Effect
The magnitude of the internal force and deformation borne by the structure or component. 2.1.10 Resistance
The ability of the structure to resist external forces. 2. 1. 11 Bridge Deck PavementThe waterproof and friction layer installed on the bridge superstructure panel 2.1.12 Traffic Deck SlabThe plate structure that bears the weight of traffic.
2.1.13 Weight (force) Density Weight (force) Density Weight per unit volume of a substance.
2.1.14 Multi-Lane Transverse Reduction Factor Multi-Lane Transverse Reduction Factor When multiple vehicles are moving on the transverse lanes of the bridge deck at different times, the structural effect should be reduced.
2.1.15 Multi-Lane Longitudinal Reduction Factor Multi-Lane Longitudinal Reduction Factor On the lanes within the straightening beam diameter model, the various light vehicles that actually appear do not meet the design axle weight and spacing of standard vehicles. The structural effect calculated according to the standard vehicle should be reduced.
2.1.16 Design Lane Design Lane refers to the width of the strip on the bridge deck for a single longitudinal column of vehicles to travel, which is determined according to the design dimensions of the bridge cross section.
Wheel contact length,
6——±pressure calculation width;
B———Calculated width of abutment or calculated length of retaining wall; C--—centrifugal force coefficient;
Diameter of column or pile:
Height from calculated section to pavement item or converted soil layer thickness, Hbzxz.net
Height of retaining wall;
Span or added length:
1. ——Standard truck front and rear wheelbase; the length of the damaged joint of the fill behind the abutment or retaining wall L——————the horizontal clear distance of the columns or piles;
abandoned one——the number of columns or piles,
horizontal strength of soil pressure
vertical strength of soil pressure,
radius of curvature of the bend or curved bridge;
travel speed,
crowd load per unit area, or soil mass; width of a lane:
gravity density of soil,
pressure coefficient of soil
impact coefficient of vehicle or lane load;
total weight of vehicle wheels arranged in the BXI area; internal friction angle of fill:
width of single-side sidewalk.
3 Design loads for urban bridges
3.1 Load classification
3.1.1 Design loads for urban bridges can be divided into three categories: permanent load, variable load and eccentric load. The load categories should adopt the provisions of Table 3.1.1. Load age classification
Classification of drug number
Wax structure gravity
Neck added virtual force
Soil force and soil pressure
Permanent load
(but general)
Variable load
Basically traceable
(live storage)
Reduced soil end and variable influence
Basic displacement influence
Buoyancy of water
Automobile impact force
High centrifugal force
Soil pressure caused by automobile
Table 3.1,1
The design loads of urban bridges can be divided into three categories: permanent loads, variable loads and possible loads. The load categories should be based on the provisions of Table 3.1.1. Variable load classification
Street classification
Automobile braking force
Water flow
Variable load
Other variable loads
Heat load
Ice pressure
Influence of load
Load name
Support
Earthquake (uncommon)
General impact force
Table 3.1.1
3.1.1 Components that are mainly designed to bear other variable loads should be regarded as basic variable loads when calculating the loads they bear. 3.2 Load combination
3.Z.1 When designing according to the ultimate limit state of bearing capacity, the following load combinations should be selected according to the loads that may appear simultaneously:
3.2. 1 Combination: One or several basic variable loads combined with one or several permanent loads
3. 2. 1. 2 Combination 1: One or several basic variable loads and one or several permanent loads are combined with one or several other variable loads: When designing a curved bridge and using a combination of centrifugal force and braking force, the braking force should be calculated as 70%1
3. 2. 1. 3 Combination 2: One or several basic variable loads and one or several permanent loads are combined with the impact force of ships or drifting objects in the accidental loads; 3. 2. 1. 4 Combination IV bridges are combined according to possible structural gravity, scaffolding, materials and equipment, crowds, wind force, and unidirectional thrust of arch bridges during construction:
The impact force generated by bridge components during construction, hoisting or transportation should be considered in the dynamic system of the components according to the specific conditions on site and design experience; 3.1.1.s Combination V: structural stiffness, prestressing, soil weight and main pressure, one or more of which are combined with earthquake force. 3.2.2 Other variable loads that are not combined at the same time should comply with the provisions of Table 3.2.2. Other variable loads that are not combined at the same time Name
Vehicle braking force
Water pressure
Bearing resistance
3. 2.2
Variable fracture water pressure, ice pressure, bearing resistance, vehicle braking force, ice pressure
vehicle braking force, water pressure
vehicle braking force
3. 2. 3 When the bridge is designed with the ultimate limit state, different load partial factors should be used according to different load combinations to verify the deformation. The cracking degree, stress and prestress state in the sugar stage, its load combination and load safety factor should comply with the relevant provisions of the current industry standard "Design Code for Steel and Prestressed Concrete Bridges" (JTI023)
3.2.4 Steel-wood structural members are still designed according to the allowable stress, and the load combination and material allowable stress values can be implemented according to the current industry standard (Design Code for Steel and Wood Structures of Highway Bridges and Culverts) (ITJ025).
3.3 Permanent loads
3. 3. 1 The gravity of the structure and the additional forces of the bridge deck and its equipment are all structural gravity densities. When actual data are lacking, the gravity density of commonly used materials can be selected according to Table 3.3.1.
Material types
Roots, shear steel
Each number
Photographic gaze at the south right mixed bag seven
Wu Le stone Xiao material stone
Jun or piece stone
Photographic cement soil
Stone magnet) stone
Charcoal king
Xiu Li
Common materials strength density
Gravity strength (kN/m*)
Table 3. 3. 1
Box weight (based on body plasticity) less than 2%
Angle 26.0kN/m
F2% of the vegetable
Including water-bound crushed stone, graded crushed (gravel) stone. 0%
3.3.2 When the structure is designed according to the limit state of normal use, the prestressing shall be calculated as a permanent load and its effect shall be included in the prestressing loss at the corresponding stage, but the additional internal force caused by the increase of eccentricity shall not be taken into account. When the structure is designed according to the limit state of bearing capacity, the prestressing shall not be used as a load. However, the prestressed steel bars shall be considered as part of the structural resistance. 3.3.3 The calculation of soil gravity and soil pressure shall comply with the following provisions 13.3.3.1 The calculation of active soil pressure and static pressure may be carried out in accordance with Appendices 1 and 2 of the current industry standard "General Specification for Design of Highway Bridges and Culverts" (JTJ021). The gravity density and internal friction angle of the soil shall be determined based on investigation or test. When there is no data available, it may be carried out in accordance with Appendix 2 of the current industry standard "Specifications for Design of Foundations and Foundations of Highway Bridges and Culverts" (JTJ024).
3.3.3.2 The directional and horizontal pressure intensity of the fill force on the vehicle can be calculated according to the following formula:
Directional pressure intensity
Horizontal pressure intensity
Lateral pressure coefficient
qv=r,h
α= tg[45° - Sign]
Gravity density of soil (kN/m)
Height from calculation surface to top of road surface (m),
: fill internal angle (\).
(3.3.3-1)
(3.3.3-2)
(3.3.3-3)
3.3.3.3 For column-type piers subjected to lateral soil pressure, the calculated width of the soil pressure on the column shall comply with the following provisions:
3.3.3 Calculation width of soil pressure on columns (1) When L:≤d, the reduction due to the space between columns shall not be considered. The calculated width of the soil pressure acting on each column shall be calculated according to the following formula: b
nd +2u
Width of the soil pressure gauge (m)
d-diameter (or width) of the column (m),
clear distance between columns or piles in horizontal rows;
(3.3.3-4)
4-19-- 5
-number of columns or piles.
(2) When 1,≥d, the reduction effect of the hollow space between columns shall be considered according to the diameter or width of the column. The calculated width of the pressure on each column shall be calculated according to the following formula: When d≤1.0m6 ~ d(2n -1)
(3.3.3-5)
When d>1.0m6 =d ±1)-1
(3.3.3-6)
3.3.4 Externally overdetermined concrete structures and combined beam bridges shall take into account the shrinkage and creep effects of concrete. And the calculation shall be carried out in accordance with the method in Appendix 4 of the current industry standards "General Specification for Design of Highway Bridges and Culverts" (JTJ021) and "Design Specification for Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts" (JTJ023). 3.3.5 When the statically indeterminate structure takes into account the influence of long-term displacement of the bearings caused by foundation compression, etc., the additional internal force of the component section should be calculated according to the elastic theory based on the final displacement. 3.3.6 The buoyancy of water should be calculated according to the following situations: 3.3.6.1 For bridge piers located on permeable foundations, when stability is verified, their buoyancy should be calculated using the design water level; when foundation stress is verified, the buoyancy can be calculated only at low water level, or the buoyancy of water can be ignored. 3.3.6.2 For bridge piers whose foundations are embedded in impermeable foundations, the buoyancy of water can be ignored.
3.3.6.3 The buoyancy acting on the bottom surface of the pile foundation cap should be calculated based on the entire bottom area. However, if the piles are embedded in the rock layer and poured with concrete, the cross-sectional area of the piles should be deducted when calculating the buoyancy of the bottom surface of the cap.
3.4 Accidental loads
3.4.1 The seismic resistance of urban bridges should be designed based on the basic intensity of the city where the bridge is located. The calculation of seismic forces and structural design should comply with the relevant provisions of the current industry standard "Highway Engineering Seismic Design Code" (JTJ004). 3.4.2 Bridge piers located in navigable rivers or rivers with drifting objects should take into account the impact force of ships or drifting objects. When there is no measured data, the impact force can be calculated according to the current industry standard "General Code for Highway Bridge and Culvert Design" (JTJ021). 4 Variable loads for urban bridge design
4. 1 Basic variable loads
The automobile load level can be divided into two levels: urban A-level automobile load and urban B-level automobile load.
4.1.2 Automobile loads can be divided into vehicle loads and lane loads. The calculation of soil pressure behind the bridge's diaphragm, driving slab, abutment or retaining wall should adopt vehicle loads. The calculation of the bridge's main beam, main arch and main frame should adopt lane loads. When light rail vehicles are running on the bridge deck, they should be checked and calculated according to the relevant light rail load regulations, and the most unfavorable one should be taken for design. When calculating the bridge structure, the effects of vehicle loads and lane loads shall not be superimposed.
Standard trucks for urban-A class vehicles and urban-B class vehicles shall comply with the following provisions:
4.1.3.1 Urban-A class standard trucks shall be loaded with five-axle trucks, with a total weight of 700kN, a front and rear wheelbase of 18.0m, and a transverse width of the driving limit of 3.0m (Figure 4.1.3-1);
4.1.3.2 Urban-B class standard trucks shall be loaded with three-axle trucks, with a total weight of 300kN, a front and rear wheelbase of 4.8m, and a transverse width of the driving limit of 3.0m (Figure 4.1.3-2)
4.1.3.3 The cross-sectional dimensions of domain-A class and domain-B class standard trucks are the same, and their transverse bridge layout shall comply with the provisions of Figure 4.1.3-3. 4.1.4 The load on the lanes of Class A and Class B vehicles in urban areas shall be calculated based on the uniformly distributed load plus a concentrated load. The standard values of uniformly distributed load and concentrated load shall be determined according to the span of the bridge and shall comply with the following provisions:
4.1.4.1 When the span is 2 to 20m4-19-6
Axle number
Axle (KN) S
Total (700kN)
Figure 4.1.3-
Axle number
Total (300kN)
Class A standard vehicle longitudinal and plan layout
City-B class standard vehicle longitudinal and plan layout diagram4.1.3-2
Figure 4.1.3-3 Calculation of residual load in transverse direction of bridgeet
(1) City-A class; When calculating the bending moment, the standard value of uniformly distributed load gm of lane load is 22.5kN /m; when calculating shear force, the standard value of uniform load gg is 37.5kN/m, and the added concentrated load P is 140kN (Figure 4.1.4-1). +140kN
4k22.3EN/m
：4g-37.5kN/ml
Figure 4, 1.4-1 Class A lane load
(2) Class B: When calculating the moment, the standard value of uniform load gM of the lane load is 19.0kN/m, when calculating shear force, the standard value of uniform load qg is 25.0kN/m, and the added concentrated load P is 130kN (Figure 4.1.4-2). P-130kN
4r-19.,0kN/ma
4=25.0kNhm
Figure 4, 1. 4-2 Urban-B Class Lane Load 4. 1. 4. 2 When the span is greater than 20m and less than or equal to 150m (1) Urban-A Class: When calculating the bending moment, the standard value of the uniformly distributed load 9M of the lane load is 10. 0kN/m, and when calculating the shear force, the standard value of the uniformly distributed load gα is 15.0kN/m, and the added concentrated load P is 300kN (Figure 4.1.4-3). When the number of lanes is equal to or greater than 4, the calculated bending moment is not multiplied by the growth factor. The calculated shear force should be multiplied by the growth factor 1. 25.
Figure 4.1.4-3 Urban A-level lane load 4ye-10akNm
9u-15.0kN/m
（2） Urban B-level: When calculating the bending moment, the standard value of the uniform load qM of the lane load is 9.5kN/m; when calculating the shear force, the standard value of the uniform load qg is 11.0kN/m, and the added concentrated load P is 160kN (Figure 4.1.4-4). When the number of vehicles passing is equal to or greater than 4, the calculated bending moment is not multiplied by the growth factor. The calculated shear force should be multiplied by the growth factor of 1.30. p-160kN
Figure 4.1.4-4. City B-load lane load Lane load transverse distribution
hr- 9.5kN/m
4g=11.0kN/m
The one-way distribution width of lane load should be 3.0m, see Figure 4.1.4-5(a). For the calculation of the transverse influence line of commercial bridge, the vehicle load can be arranged in the equivalent load wheel concentrated force form shown in Figure 4.1.4-5 (5). Stone
Figure 4.1.4-5 Lane load transverse distribution 4.1.5 The relationship between the number of design lanes n and the total lane separation W, can be determined according to Table 4.1.5.
Relationship between the number of designed vehicles and the total height of the laneTotal lane comfort W. (m)
7. 0kW14.0
14. 0≤W<17. 5
17. 5≤W21.0
21.0W24.5
24. 5xw28. 0
28. 0≤W,<31. 5
Number of designed lanes
Table 4. 1. 5
Double inner lane comfort w. (m)
7. 0kW14. 0
14. 04-3 Urban A-level lane load 4ye-10akNm
9u-15.0kN/m
（2） Urban B-level: When calculating the bending moment, the standard value of the uniform load qM of the lane load is 9.5kN/m; when calculating the shear force, the standard value of the uniform load qg is 11.0kN/m, and the added concentrated load P is 160kN (Figure 4.1.4-4). When the number of vehicles passing is equal to or greater than 4, the calculated bending moment is not multiplied by the growth factor. The calculated shear force should be multiplied by the growth factor of 1.30. p-160kN
Figure 4.1.4-4. City B-load lane load Lane load transverse distribution
hr- 9.5kN/m
4g=11.0kN/m
The one-way distribution width of lane load should be 3.0m, see Figure 4.1.4-5(a). For the calculation of the transverse influence line of commercial bridge, the vehicle load can be arranged in the equivalent load wheel concentrated force form shown in Figure 4.1.4-5 (5). Stone
Figure 4.1.4-5 Lane load transverse distribution 4.1.5 The relationship between the number of design lanes n and the total lane separation W, can be determined according to Table 4.1.5.
Relationship between the number of designed vehicles and the total height of the laneTotal lane comfort W. (m)
7. 0kW14.0
14. 0≤W<17. 5
17. 5≤W21.0
21.0W24.5
24. 5xw28. 0
28. 0≤W,<31. 5
Number of designed lanes
Table 4. 1. 5
Double inner lane comfort w. (m)
7. 0kW14. 0
14. 04-3 Urban A-level lane load 4ye-10akNm
9u-15.0kN/m
（2） Urban B-level: When calculating the bending moment, the standard value of the uniform load qM of the lane load is 9.5kN/m; when calculating the shear force, the standard value of the uniform load qg is 11.0kN/m, and the added concentrated load P is 160kN (Figure 4.1.4-4). When the number of vehicles passing is equal to or greater than 4, the calculated bending moment is not multiplied by the growth factor. The calculated shear force should be multiplied by the growth factor of 1.30. p-160kN
Figure 4.1.4-4. City B-load lane load Lane load transverse distribution
hr- 9.5kN/m
4g=11.0kN/m
The one-way distribution width of lane load should be 3.0m, see Figure 4.1.4-5(a). For the calculation of the transverse influence line of commercial bridge, the vehicle load can be arranged in the equivalent load wheel concentrated force form shown in Figure 4.1.4-5 (5). Stone
Figure 4.1.4-5 Lane load transverse distribution 4.1.5 The relationship between the number of design lanes n and the total lane separation W, can be determined according to Table 4.1.5.
Relationship between the number of designed vehicles and the total height of the laneTotal lane comfort W. (m)
7. 0kW14.0
14. 0≤W<17. 5
17. 5≤W21.0
21.0W24.5
24. 5xw28. 0
28. 0≤W,<31. 5
Number of designed lanes
Table 4. 1. 5
Double inner lane comfort w. (m)
7. 0kW14. 0
14. 0
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