What are the regulations and requirements for the preliminary design of bridges and culverts?

1. The two-way four-lane expressway standard with a design speed of 80Km/h is adopted. The width of the integral roadbed is 24.5m. The standard section of the bridge is shown in the figure below:

2. The design load level of main line bridges and culverts: Highway-I level;

The road to be handed over (expressway and first-class highway: highway-class I, second-class road and third- and fourth-class roads: highway-class II; below class four: highway-class II multiplied by 0.6 to 0.8 coefficient) .

3. Earthquake action: the peak acceleration of the earthquake is 0.05g.

4. Design flood frequency: 1/300 for extra large bridges, 1/100 for large, medium and small bridges and culverts.

5. Considering the possibility of implementing the maintenance cover and the traffic safety of some special super-high vehicles in the future, and considering the requirements of construction clearance, the clearance height of bridges crossing county roads (including county roads) and above grades should be increased to 5.5 as much as possible m, marked as 5.5 m; cement roads and country roads marked as 5.0 m, and other marked as 4.5 m.

1. General diagram of the superstructure of the main line bridge (including quantity table, standard cross-section, general structure diagram, beam layout)

20m prestressed concrete small box girder (integral subgrade 0°, 15°, 30°)

25m prestressed concrete small box girder (integral subgrade 0°, 15°, 30°)

30m prestressed concrete small box girder (integral subgrade 0°, 15°, 30°)

40m prestressed concrete small box girder (integral subgrade 0°)

For specific drawings, please refer to the general drawings of the superstructure of each span

2. General diagram of the substructure of the bridge on the main line (corresponding to the general diagram of the superstructure of the bridge on the main line)

Prestressed concrete split small box girder (including general structure diagram of 20, 25, 30m, 40m span abutment and bridge pier)

3. General map of culverts

ф1.5m reinforced concrete circular pipe culvert (0°～45°, 5° level 1)

2.0, 4.0, 6.0m reinforced concrete cover culvert (0°～45°, 5° level 1)

2.0, 4.0, 6.0m reinforced concrete box culvert (0°～45°, 5° level 1)

4. The design contents of ordinary bridges and ramp bridges include (arranged in the order of publication of drawings):

A) Quantity list of the whole bridge project

B) Bridge site plan

C) Engineering geological longitudinal section of the bridge site (the unified design of the geological survey unit, special or complex geological conditions of the bridge also need to provide engineering geological plan)

D) Comparison table of bridge schemes (general bridges do not have, bridges with comparison schemes need to be added, the specific style is as shown in the figure below)

E) Bridge type layout (horizontal and vertical data tables are drawn for the middle bridge and bridges above the middle bridge)

F) Cross-sectional view of the superstructure (mainly for the sections of prefabricated variable-width mainline bridges and interchange ramp bridges, which will not be published for standard-width bridges)

G) Construction process diagram (for special structures such as long-span variable-section box girders)

H) General structure diagram of special structure

I) Layout of steel beams for special structures

J) General structural diagram of abutments (mainly abutments for interchange ramps, abutments with widened main lines or U abutments; U abutments require the amount of concrete and the quantity of filling and excavation for each part of the structure)

K) General structure diagram of bridge piers (mainly transition piers, inter-ramp piers, and bridge piers of special structures; non-special piers of prefabricated structures will be published by the general diagram below, and will not be published for specific bridges)

5. Comparison plans (comparison plans should be drawn for both special-structure bridges and super-large bridges), which should include all the above-mentioned drawings except the "Bridge Scheme Comparison Table" at the same time;

6. For culverts and passages, only quantity tables are provided; for small bridges and overpasses, only typical style drawings and quantity tables are provided.

7. For separated overpasses, the plan, longitudinal and cross-sectional views of the bridge to be designed shall be added on the basis of the drawings required for ordinary bridges.

1. When the project is not restricted by terrain and features, the bridge span shall be carried out according to the following principles layout:

(1), average pier height H<20m, choose 20m prestressed concrete small box girder

(2), 20m≤average pier height H<25m, choose 25m prestressed concrete small box girder

(3), 25m≤average pier height H<35m, choose 30m prestressed concrete small box girder

(4), average pier height H≥35m, choose 40m prestressed concrete small box girder

There are three angles of 0°, 15°, and 30° in the general diagram of the above-mentioned small span box girder structure. In practical applications, when the structural angle is greater than 30°, the difference in slope can be accommodated by increasing the standard span.

2. The filling height of the bridge head subgrade in this project should be controlled according to the allowable post-construction settlement, and should not be higher than 10m. Generally, it can be controlled at about 8m. When the filling height of the abutment is greater than 10m, in principle, additional construction should be made Bridge, but under the premise of ensuring the stability of the abutment, the filling height of the abutment can be appropriately increased and the bridge length can be shortened. Special circumstances should be decided through consultation with the project department.

3. Environmental conditions: Class I;

4. The strength grade of concrete for this project is suggested in the following table:

5. The length of the pile foundation must be calculated for each bridge, and the pile length calculation book should be given. The reaction force at the pier top of each span of the prefabricated structure is as follows:

6. The bridge type diagram must contain the following contents: intersecting road pile number, intersection angle, elevation, clearance before and after widening, road name, direction; mark river name, flow direction, time measurement water level, maximum navigable water level, navigation Clearance requirements and design flood level; mark the position of pipelines and optical cables; mark geological boreholes and their numbers and pile numbers, corresponding to the bearing capacity value and friction value of the soil layer; for different upper and lower structures, their section diagrams should be given; they should be drawn Schematic diagram of structural division; parameter table of pier height and pile length; elevation of pier cap and pile bottom or enlarged foundation.

The starting point and ending point of the bridge are uniformly marked. When the horizontal terrain at the bridge position is relatively gentle, only the ground line at the design line may be indicated.

The format requirements for notes in bridge layout drawings are as follows:

“Note:

1.The size of this picture is in centimeters, and the pile number and elevation are in centimeters meter meter.

2. Car Load Class: Highway—IClass (or Highway— IILevel).

3.The plane of this bridge is located in the radiusR—< strong >0000mleft /On the right-sided circular curve (on the transitional curve), the vertical plane is located atR—00000mConcave/ on a convex vertical curve (±0.00 %Single/ Two-way slope).

4.The superstructure of this bridge adopts00mPrestressed concrete split small box girder (< /em>Tbeam), simply supported/Simplified support first and then continuous structure, the division is as follows:< /span>0×00+0×00+…; the substructure adopts double-column piers, bored pile foundations, piles (rib) type abutment, enlarged foundation.

5.The inner guardrail of this bridge is reinforced< /em>SBmlevelF type reinforced concrete wall guardrail, the outside adopts< /strong>SBgrade reinforced concrete wall guardrail . [ ]m Long board.

6.This bridge uses< /strong>GYZ/GPZsupport, please refer to the structure for specific modelsSchematic diagram of the branch.

7.This bridge uses< /strong>D80( D160) The modular expansion joints have a total of ×× channels, respectively located in 0#Taiwan, 3#Tunhe< em >5#Taiwan.

8.This bridge crosses the ×× River and[S113]Dart road, please refer to the specific intersection angle and cross stake number The floor plan shows that the ×× River[is × level fairway, clearance requirementsa× bm]No navigable requirements.

9. (with other special instructions). "

This project mainly adopts reinforced concrete cover culvert (channel) and circular pipe culvert;

1. For mountainous road sections, in principle, reinforced concrete circular pipe culverts should not be used as much as possible on the main line, and circular pipe culverts can be installed according to the actual situation in flat areas where conditions permit. In order to facilitate dredging, the minimum aperture of the culvert should not be less than 1.5m.

2. When the filling height of the top of the culvert does not exceed 12m in general road sections, reinforced concrete cover culverts are used; For a reasonable design scheme, if culverts are recommended, reinforced concrete slab culverts or concrete arch culverts can be used according to the geological conditions of the foundation, which are specially designed by each design unit.

3. In order to improve the driving conditions on the road surface, under the condition that the filling height and drainage meet the requirements, dark culverts/channels should be used as much as possible.

4. When the channel length is greater than or equal to 50m, a lighting well must be installed.

1. According to the requirements of the document legend of the Ministry of Communications, all drawings of this project shall use "note", "Notes" are not used.

2. The marked arrows are uniformly single arrows;

3. The design document adopts A3 format, and the extended A3 diagram is divided into standard A3 format for printing, so as to facilitate document publication.

4. Font: The frame uses imitation Song _GB2312, and the drawing uses FSDB and FSDB_E. Character height: height 5 for titles and section symbols, height 4 for notes and directions, height 3 for characters in tables, height 2.5 for annotations and descriptions, and 2.0 for drilling descriptions; the actual height of characters is the specified height × global ratio. Width Scale: 0.75.

5. The picture title in the picture frame is divided into upper and lower layers.

Indicate the name of the bridge on the upper layer. The general bridge with integral subgrade is: Kxxx+xxx XXX bridge (plan 1), and the bridge with staggered holes on integral subgrade is: left K11+655.5/right K11+635.5 XXX bridge (plan 1).

Indicate the name of the drawing in the lower layer: Bridge layout drawing, and the upper right corner of the drawing frame is marked as the "page number/pages in total" of the drawing.

6. For other matters that are not detailed, please submit them for discussion in time to improve this regulation and strive to unify the design documents.