1 General Provisions
1.0.1 This standard is formulated with a view to unify the design technology standards of highway bridge and culverts, to implement the related laws and highway technical policies, and to make the design of highway bridge and culverts to meet the requirement of state-of-art technology, safety and reliability, application and duration, and economic feasibility.
1.0.2 This standard is formulated in accordance with the principles specified in "Unified standard of reliability design of highway engineering structures" (GB/T 50283) and the relevant regulations in "Technical Standard of Highway Engineering" (JTG B01).
1.0.3 This standard is applicable to the structure design of new and rebuilt highway bridge and culverts at all classes.
1.0.4 The line shape of the highway bridge / culvert and slip roads shall be inconsistent with the general arrangement of the road line.
1.0.5 Besides highway bridges and culverts shall meet the article 1.0.1 in consideration of highway function, property and future expansion, it shall be designed on the principles of esthetic appearance and environmental protection, combined with the factors "adaptation to local conditions", "using local materials" and "convenient for construction and maintenance".
The bridges and culverts arranged with standard span should be fabricated structure, and is applicable to Mechanized and factorial construction.
1.0.6 The design reference period of highway bridge / culvert structure shall be 100 years.
1.0.7 Highway bridge / culvert structure shall be designed under bearing capacity limit state and normal use limit state.
1 Bearing capacity limit state: it is referred to the state when bridge / culvert structure or its element reaches the max carrying capacity or has the deformation or displacement which is not suitable to continue bearing loads.
2 Normal use limit state: it is referred to the state when the bridge / culvert structure or its element reaches certain limit of normal use or endurance.
The designs of above two limit state designs shall satisfy the requirements of structure and technology.
1.0.8 According to actions (or load) or its influence on bridges and culverts, and location environmental condition, highway bridges and culverts shall be treated with corresponding limit designs.
1 Persistent situation: it is referred to the situation of long duration that bridges and culverts near deadweight and automobile load after being constructed. The bridges and culverts under this situation shall be treated with bearing capacity limit state and normal use limit state designs.
2. Transient situation: it is referred to the situation that bridges and culverts bear temporary actions in the construction course. The bridges and culverts under this situation is only treated with bearing capacity limit state design, and normal use limit state design only when necessary.
3 Incidental situation: it is referred to the situation that the bridges and culverts occur incidentally in the use course. The bridges and culverts under this situation are only treated with bearing capacity limit state design.
1.0.9 Treated with bearing capacity limit state design under persistent situation, the design safe class of highway bridge and culvert structure shall be divided in to 3 design classes according to the severity of the consequent effect that may be caused by structural damage. And it shall not be lower that the specified values in Table 1.0.9.
Table 1.0.9: Design safe class of highway bridge and culvert structure
Design safe class Bridge /culvert structure
Class I Grand bridge, larger important bridge
Class II Large bridge, medium bridge and small important bridge
Class III Small bridge and culvert
Note: Grand, large and medium bridges listed in the table are determined according to the single-hole span specified in Table 1.0.11. As for multispan and unequal-span bridge, the safe class is determined according to the largest span;
The Large bridge and small bridge marked with "important" refer to bridges located in expressway and first-class highway, national defense highway and busy highway nearby cities.
As for the highway bridge and culvert with special purpose, the design safe class may be determined according to specific circumstances. The safe class of structural elements for same bridge / culvert shall be same to one of the overall structure. If there is special requirement, the safe class may be adjusted, but the adjusted class shall not be higher than by Class I.
1.0.10 Special large bridge should be treated with landscape design; bridges for expressway with span, first-class highway shall coordinate with natural environment and landscape.
1.0.11 Grant, large, medium and small bridge, and culvert shall be classified according to single-hole span or total length of multihole span (Table 1.0.11).
Table 1.0.11: Classification of bridge / culvert
Bridge / culvert classification Total length of Multihole span L(m) Single-hole span Lk (m)
Grand bridge L> 1000 LK>150
Large bridge 100≤L≤1000 40≤LK≤150
Medium bridge 30≤L≤100 20≤LK<40
Small bridge 8≤L≤30 5≤LK <20
Culvert - Lk<5
Note: (1) Single-hole span refers to standard span;
(2) The total length of Multihole span of Girder bridge and plate bridge is the total length of Multihole standard span; the one of arch bridge is the distance between arch spring lines at abutments; the one of other bridge is the length deck roadbed;
(3) No matter what the pipe diameter or span is, Pipe culvert and box culvert all are named as culvert;
(4) Standard span: as for girder bridge and plate bridge, it is the length of the center line between the midlines of two piers, or the length of the center lines between face-lines at the back of abutments; as for arch bridge and culvert, it is the clear span.
1.0.12 Besides highway bridge and culvert design shall be taken out with quality control in accordance with the related technical management system, the relevant requirements, concerned with structure design, material property, structure durability, fabricating and construction technology that must be specialized, and bridge / culvert operating condition shall be proposed in the design documentation.
1.0.13 Highway bridge and culvert design shall comply with this standard and the structure design shall meet the provisions of the related current national standards.
2 Terms
2.0.1 Action
It is referred to a group of single force or distributed force stressed on structures, or reasons causing imposed deformation and restrained deformation. The former is also called as direct action or load, and the later is called as indirect action.
2.0.2 Permanent action
It is referred to the action which the value does not change wit time, and the comparison of its value and the mean value hereof can be negligeable in the service time of the structure.
2.0.3 Variable action
It is referred to the action which the value change with time, and the comparison of its value and the mean value hereof can be nonnegligible in the service time of the structure.
2.0.4 Accidental action
It is referred to the action which the probability is smaller in the service time of the structure, but the value is larger and the duration is short once it appears.
2.0.5 Representative value of an action
It is referred to the specified value of actions, which is used for different purposes in the design of the structure or the elements. it includes action characteristic value, quasi-permanent value and frequent value.
2.0.6 Characteristic value of an action
It is referred to the main representative value of actions in structure and the elements, which the value can be determined according to certain fractile in the max action probability distribution during the design reference period.
2.0.7 Design reference period
It is referred to the reference time parameter used for basic variable and time relationship under the persistent design state in the structural reliability analysis.
2.0.8 Frequent value of an action
It is referred to a representative value of variable action adopted when the structure or elements are designed according to Combination for short-term action effects under normal use limit state, which the value can be determined according to the fractile 0.95 of the point probability distribution at any action time during a observation period long enough.
2.0.9 Quasi-permanent value of an action
It is referred to another representative value of variable action adopted when the structure or elements are designed according to Combination for long-term action effects under normal use limit state, which the value can be determined according to the fractile 0.5 (slightly larger than 0.5) of the point probability distribution at any action time during a observation period long enough.
2.0.10 Effect of an action
It is referred to the response of the structure to the stressed actions, like bending moment, torque, and displacement.
2.0.11 Design value of an action effect
It is referred to the product of the characteristic value effect and the partial safety factor of the action.
2.0.12 Partial safety factor
It is referred to the factor adopted in the design expression, which is used for ensuring the specified reliability of the designed structure. it is includes action partial safety factor and partial safety factor of resisting force.
2.0.13 Combination for action effects
It is referred to the random superimposition of effects caused by several actions stressed on the structure.
2.0.14 Coefficient for importance of a structure
It is referred to the coefficient used for ensuring the specified reliability of the structure at different safe classes.
2.0.15 Coefficient of combination for action effects
It is referred to the reduction coefficient of an action when effect of several variable actions has worst values with smaller probability in a combination for action effects.
2.0.16 Fundamental combination for action effects
It is referred to the combination of the design value effect of permanent action and variable action under bearing capacity limit state.
2.0.17 Accidental combination for action effects
It is referred t the combination of characteristic value effect of permanent action characteristic value, effect of certain representative value (of variable action), and a effect of accidental action characteristic value in the bearing capacity limit state.
2.0.18 Combination for short-term action effects
It is referred to the combination of effect of permanent action characteristic value, and effect of variable action frequent value under Normal use limit state design.
2.0.19 Combination for long-term action effects
It is referred to the combination of effect of permanent action characteristic value, and effect of variable action quasi-permanent value under Normal use limit state design.
3 Design Requirements
3.1 Bridges and Culverts Layout
3.1.1 Bridges shall be designed according to highway Function, class, trafficability and the requirements of disaster prevention, and in combination with the conditions such as hydrochemistry, Geology, navigation and environment.
1 General Provisions
2 Terms
3 Design Requirements
3.1 Bridges and Culverts Layout
3.2 Bridge / Culvert Hole Size
3.3 Bridge / Culvert Clearance
3.4 Bridge Alignment and Bridge Approach
3.5 Structure Requirements
3.6 Deck Pavement, Drainage and Water Proof Layer
3.7 Maintenance and Other Appurtenant Works
4 Action
4.1 Action Classification, Representative Value and Combination for Action Effects
4.2 Permanent Action
4.3 Variable Action
4.4 Accidental Action
Annex A
Annex B
Explanation of Wording
