1.0.1 This code is formulated with a view to make the design of highway bridges and culverts meet the requirements of state-of-art technology, safety and reliability, durability and applicability as well as economic feasibility.
1.0.2 This Code is applicable to the design of the general reinforced concrete and prestressed concrete structural members for highway bridges and culverts, and it is not applicable to the design of light aggregate concrete structural members or other special concrete structural members.
1.0.3 This Code is formulated according to the design philosophy specified in the national standard "Unified standard of reliability design of highway engineering structures" (GB/T 50283-1999). The basic terms and symbols are adopted according to the requirements of the national standard “Basic terms and general symbols of structure deign" (GBJ 132-90) and "Terms of Road Construction" (GBJ 124-88).
1.0.4 This Code adopts probabilistic theory-based limit design method and designs according to the designed expression of partial safety factor.
The design reference period of this Code is 100 years.
1.0.5 The following two limit designs shall be carried out for the highway bridges and culverts:
1 Bearing capacity limit state: it corresponds to the state when the bridges and culverts and their members reach the maximum carrying capacity or deformation or deflection occurs indicating the aforesaid are not suitable for continuous bearing.
2 Regular service limit states: it corresponds to the certain state when the bridges and culverts and their members reach the limit of regular service or durability.
1.0.6 The following three design situations and their corresponding limit design shall be considered for the highway bridges and culverts:
1 Persistent situation: it refers to the situation that the finished bridges and culverts sustain their deadweight and car load etc. for a very long time. Bearing capacity limit state design and regular service limit state design shall be carried out for such bridges and culverts.
2 Transient situation: it refers to the situation when the bridges and culverts sustain temporary action (or load) in the construction process. Bearing capacity limit state design shall be carried out for such bridges and culverts, and regular service limit design can be carried out when necessary.
3 Accidental situation: it refers to the situation that a sporadic earthquake occurs when the bridges and culverts are under usage. Bearing capacity limit design is the only design required for such bridges and culverts.
1.0.7 According to the environmental conditions, the durability design shall be carried out for the highway bridges and culverts. The basic requirements of durability for the structural concrete shall meet the requirements of Table 1.0.7.
Table 1.0.7 Basic Requirements of the Durability for Structural Concrete
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Environment classification
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Environmental condition
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Maximum water cement ratio
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Minimum cement content(kg/m3)
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Minimum concrete strength level
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Maximum chloride ion content (%)
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Maximum alkali content(kg/m3)
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I
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Atmospheric environment in warm or cold regions and environment with no connection to corrosive water or soil
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0.55
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275
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C25
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0.30
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3.0
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II
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Atmospheric environment in chilly areas, ice-removal salt-used environment and littoral environment
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0.50
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300
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C30
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0.15
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3.0
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III
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Briny environment
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0.45
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300
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C35
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0.10
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3.0
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IV
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Environment influencing by corrosive substance
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0.40
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325
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C35
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0.10
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3.0
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Note: (1) If the maximum water cement ratio and minimum cement content of structural concrete in the briny environment are specified in more detail in relevant governing codes, these codes may be complied with;
(2) The chloride ion content in the Table refers to the percentage of chloride ion to cement content;
(3) With actual engineering experience, the minimum strength level of structural concrete under Class I environment can be a grade lower what specified in the Table;
(4) As for the prestressed concrete members, its maximum chloride ion content is 0.06%, minimum cement content is 350kg/m3, minimum concrete strength level is C40 or three grades higher than what specified in Class I environment or two grades higher than other types of environments;
(5) As for the outsized and large bridges, the maximum alkali content of concrete should be reduced to l.8kg/m3; when it is under Class III, �� or ice-removal salt-used and littoral environment, non-alkali aggregate should be adopted. The definitions for outsized bridges and large bridges are given in Table 5.1.2 of this Code.
1.0.8 As for the bridge bridges under Class III or Class IV environment, if the durability in required, their major tension reinforcement should be epoxy coating steel reinforcement; and special protective measures shall be adopted for the prestressed reinforcement, anchorage and connectors.
1.0.9 As for structural concrete in mobile water region and with freezing resistance requirements, its freezing resistance rating shall not be lower what specified in Table 1.0.9.
Table 1.0.9 Standard for Selection of Freezing Resistance Rating of Concrete in Mobile Water Regions
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Bridge location
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Briny environment
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Freshwater environment
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Severely frost areas (with the monthly mean temperature of the coldest month lower than -8��)
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F350
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F250
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Frost areas (with the monthly mean temperature of the coldest month between -4��~-8��)
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F300
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F200
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Partial freezing areas (with the monthly mean temperature of the coldest month between 0��~-4��)
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F250
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F150
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Note: (1) The freezing test method for concrete shall meet the requirements of the current standard "Testing Methods of Concrete for Highway Engineering" (JTJ 053-94);
(2) The freezing resistance rating for pier and platform concrete shall be a grade higher than what specified in the Table.
The frost-resistant concrete shall be added with proper amount of air-entraining agent, the air content of the mixture shall meet the current code "Technical Specifications for Construction of Highway Bridges and Culverts" (JTJ 041-2000).
1.0.10 As for the structural concrete with impervious requirements, its impermeability rating shall meet the requirements of Table 1.0.10.
Table 1.0.10 Standard for the Selection of Impermeability Rating for Structural Concrete
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Ratio of the maximum acting head to concrete wall thickness
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Impermeability rating
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Ratio of the maximum acting head to concrete wall thickness
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Impermeability rating
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