Some standard content:
Industry Standard of the People's Republic of China
Design Standard for Urban Bridges
CJJ 11--93
Editor: Shanghai Municipal Engineering Design Institute Approval Department: Ministry of Construction of the People's Republic of China Effective Date: October 1, 1993 481
Notice on the Issuance of Industry Standard "Design Standard for Urban Bridges"
Jianbiao [1993] No. 320
According to the requirements of the former State Administration of Urban Construction (81) Chengkezi No. 13, the "Design Standard for Urban Bridges" edited by Shanghai Municipal Engineering Design Institute has been reviewed and approved as an industry standard, numbered CJ11-93, and will be implemented from October 1, 1993. This standard is managed by the Ministry of Construction's urban road bridge standard technology unit 4-8-2
Beijing Municipal Design Institute is responsible for centralized management, the editorial unit is responsible for specific interpretation, and the Ministry of Construction's Standard and Quota Research Institute organizes publication. Ministry of Construction of the People's Republic of China
May 3, 1993
General Provisions
Bridge Location Selection and Layout
Design Load Standard and Clearance
Vehicle Load
Crowd Load
Other Loads
Plan, Longitudinal and Cross Sections of Bridge Deck
4—8—5
.4—8—8
4—8—-9
-8—9
Bridge Beam approach road, approach bridge
Detailed structure and ancillary facilities
Grade separation
General provisions
8.2 Overpass
Overpass and
Appendix A
Explanation of terms used in this standard
Additional notes
—8-12
4—8—12
-8—12
-8—13
-8-—13
4-8— 3
In order to properly deal with issues related to bridge construction when designing roads and bridges in urban construction, ensure the quality of bridges and give full play to the benefits of bridge nests, this standard is formulated. 1.0.2 This standard is applicable to the design of new permanent bridges and underground bridges on urban roads. It can also be used as a reference for the reconstruction of bridges.
1.0.3 The construction of urban bridges shall comply with the relevant provisions of the Urban Planning Law of the People's Republic of China, and shall comply with the requirements of convenience, traffic development and urban development, and shall be designed in accordance with the principles of applicability, safety, economy and beauty. 1.0.4 In addition to implementing this code, the design of urban bridges shall also comply with the provisions of the relevant national standards in force.
General provisions
2.0.1 Urban bridges can be divided into four categories: super-large bridges, large bridges, medium bridges and small bridges according to the total length of their multi-hole spans or the length of their single-hole spans, as shown in Table 2.0.1. Urban bridges with a total width greater than or equal to 30m can be upgraded one category based on the original classification. Urban bridges are classified according to their total length
2. a. 1
Bridge classification
Extra-large bridge
Total length of multi-hole diameter (m)
≥500
500>2100
100>30
30≥≥8
Single-hole diameter (M)
100>to2≥40
40>o≥20
20>t0≥5
Note, the total length of multi-hole diameter is only used as an indicator to divide large, medium and small bridges. The total length of the dense hole diameter is the higher of the bridge bridge; the arch type is the height between the two single abutments, and the other types of bridges are the length of the bridge deck system and the carriageway. 2.0.2 The design of urban bridges should meet the requirements of urban planning. If the project needs to be implemented in stages due to technical and economic reasons, room for future development should be reserved. 2.0.3 The design of urban bridges should adopt a flood rate of once in a hundred years. For particularly important bridges, it can be increased to once in three hundred years. In areas with low flood control standards, if the design is based on a flood rate of once in a hundred years or once in three hundred years, resulting in a high bridge deck elevation and causing difficulties, it can be considered according to actual conditions, but the safety of the bridge structure under the frequency of once in a hundred years or once in three hundred years must still be ensured. On non-navigable rivers, the bottom of the beam of urban bridges should be 0.5m higher than the design flood level (including water and wave height), 0.75m higher than the highest drift ice water level, and the arch foot should be 0.25m higher than the design flood level, and 0.25m higher than the drift ice water level. Note: (11) The arch of an ageless arch bridge is allowed to reduce the design water supply level, but it should not exceed 2/3 of the arch height. The net height of the designed water supply level of the bottom surface should not be less than 1.0m. (2) The above minimum net height and the net height of Note (1) should be appropriately increased according to the flow rate, the riverbed accumulation, and the influence of system changes and ice changes. 2.0.4 The aperture of urban bridges should be arranged according to the approved river and (or) waterway regulation plan in the urban planning and combined with the current situation. If there is no plan, it should be arranged according to the current situation and the design flood flow to meet the flood discharge requirements and navigation requirements. It is not advisable to change the natural state of the water flow too much. 2.0. 5. The navigation level of the navigable river that the bridge is suspected to cross should be in accordance with the waterway level of the approved regional city planning. The navigation clearance should comply with the current "Inland River Navigation Standard" (GBJB9-90). If the selected navigation water level conflicts with the city's existing flood control standards, road standards, terrain and vehicle traffic, it should be determined according to the specific situation. For coastal rivers affected by tides, the navigation water level can be in accordance with the regulations of the relevant departments; if not, the average flood and high tide level can be used. For cities on the sea plain, when the tidal shadow is large, and the shipping requirements conflict with the implementation of the "Inland Navigation Standards" for urban transportation, the navigable water level and clear height should be determined based on the specific situation and comprehensive research. The principles are:
(1) Most ships should have enough time to pass through every day; (2) A few large ships have the opportunity to pass through every day, 4-8-4
(3) For large ships that do not often cross the bridge (occasionally enter and exit), it can be considered to pass under restricted conditions.
2. 0.6 Urban bridge construction should reflect the style of the times, meet the requirements of urban planning and be coordinated with the surrounding environment.
The overall design of the bridge should comply with the principles of architecture, pay attention to the spatial proportion, section, light and shade and sense of stability, distinguish the primary from the secondary, and the main part should be subordinate to the main part. The focus of bridge construction should be on the overall layout and the main structure, in order to shape the beauty of the bridge as a spanning engineering structure. Create a clear and bright architectural form. The architectural beauty should be loyal to the reasonable force structure, and no excessive decoration should be added outside the structure. 2.0.7 The design of urban bridges should be adapted to local conditions, actively adopt new structures and new processes, and widely absorb advanced technologies at home and abroad, and adopt mechanization and factory-based construction. The components of medium and small bridges should adopt standardized component design. The design should ensure that the bridge channel is unobstructed during use and convenient for maintenance and repair. 2.0. 8 Bridge structures shall comply with the following provisions. (1) Components shall have the specified strength, rigidity, stability and durability during manufacturing, transportation, installation and use; (2) Components shall reduce the stress caused by additional forces, local forces and eccentric forces; (3) The selected type shall be convenient for construction, construction and maintenance; (4) The design and layout of urban bridge structures in earthquake zones shall comply with the relevant provisions of the current "Highway Engineering Anti-seismic Design Code"; (5) When curved bridges and slope bridges must be built due to urban area conditions, they should be designed as special bridges based on their specific characteristics. 2.0.9 Urban bridge designs shall include lighting, traffic signal signs, navigation signal signs, bridge deck drainage, maintenance, safety and other related facilities. 2.0.10 Sewage pipes, gas pipes and other flammable, toxic or corrosive liquid and gas pipes shall not be laid on bridges. If conditions permit, it is allowed to lay telecommunication cables, heat pipes, water pipes, and distribution cables with a voltage not higher than 10kV on the bridge, but effective safety protection measures must be taken. On bridges in suburban areas, it is allowed to pass gas distribution branches with a small diameter. The laying position should be outside the bridge railing and maintain an appropriate height. 3.0.1 The location of urban bridges should be determined based on urban planning, short-term and long-term traffic flow and flow requirements, hydrology, shipping, topography, geology and other conditions, as well as the impact on adjacent structures and public facilities. The location of medium and small bridges should be arranged according to the direction of urban roads. 3.0.2 The longitudinal axis of the bridge should be orthogonal to the river. If conditions are limited, oblique or curved bridges can also be considered.
3.0.3 In addition to meeting the requirements of the overall urban planning, the selection of bridge sites should also meet the following requirements:
(1) It should be suitable for the direction and volume of urban vehicle traffic and pedestrians, and must be convenient to use and attract various vehicles and pedestrians to cross the bridge; (2) The site of the underwater bridge should be selected in the river section where the river is straight, the river beach is narrow, and the riverbed is stable.The deviation angle between the flow direction of the high water level water flow and the flow direction of the medium and normal water level water flow at the bridge location is the smallest, and it should also comply with the "Inland Navigation Standard" (GBJ139-90) (3) For navigable rivers with piers in the water, the following conditions should also be considered: ① The axis of the pier (platform) along the water flow direction should be consistent with the water flow direction as much as possible, and its deviation angle should not exceed 5". If it exceeds, the clear navigation width must be increased accordingly. ②- Generally, there should be no less than two navigation holes. On wider rivers with busy water transportation, multiple navigation holes should be set up; if the river width is less than two navigation holes, one should be set up. Cross the hole. On restricted waterways, it is advisable to cross the hole with one hole.
③ The bridge should be away from dangerous beaches, estuaries, confluences or port operation areas and anchorages. ① The length of the straight section of the river upstream of the bridge shall not be less than 4 times the length of the pusher fleet, 3 times the length of the towing fleet or towing fleet, and the length of the straight section downstream shall not be less than 2 times the length of the pusher fleet, 1.5 times the length of the towing fleet or towing fleet. For rivers that are greatly affected by tides (double-flow water), the length of the upstream and downstream straight sections shall not be less than 3 times the length of the pusher fleet, 2 times the length of the towing fleet or towing fleet. times, ③ the distance between the axes of two adjacent bridges shall not be less than the sum of the length of the fleet plus the 5-minute voyage of the fleet for Class I to V channels, and 3 minutes for Class II and I channels. If the distances required by ④ and ③ cannot be guaranteed, navigation safety measures must be taken in the design layout of navigation.
3.0.4 The bridge site should be selected in a river section with a narrow river channel, good geology and high foundation bearing capacity, and should not be located in a river where there is a landslide; piers and platform foundations should not be set in places where faults and karst caves are seriously developed
3.0.5 The bridge site should avoid debris flow areas. When it is impossible to avoid it, it is advisable to build a long-span bridge across the debris flow area. When there are no conditions to build a long-span bridge, the sedimentation area should be avoided. It can be crossed in the flow area. The bridge should not be arranged at the place where the longitudinal slope of the riverbed changes from steep to gentle, the cross-section changes suddenly, or the bend on the plane, so as to avoid blocking and depositing the debris flow. 3.0.6 No overhead high-voltage wires shall be installed above the bridge. When there are overhead high-voltage wires on the side of the bridge, the horizontal distance between the bridge side and the overhead wires shall not be less than the height of the tower (pole).
Design load standard and clearance
Vehicle load
4. 1. 1. The motor vehicle load used in the design of urban bridge cases is divided into calculated load and verified load. 5Z.skN st. SN
[5.15] Ls.25n]
14 3N 12. 5kN
[.12.%][13. 15]
Longitudinal arrangement of vehicle head
Plane arrangement of vehicle head
SE.SkN S.5hM
[5 251][5
1Ez.5kN 122.StN
[12. 2be [. 5]
Longitudinal arrangement of vehicle head
Plane arrangement of vehicle head
Three types of loads and special loads
Calculation loads are represented by vehicle fleets:
Verification loads are represented by trucks and flatbed trailers; special loads are represented by special flatbed trailers. (1) Calculation load (vehicle load): All vehicle loads specified in the current "General Specification for Design of Highway Bridges and Culverts" are adopted. The longitudinal arrangement and transverse arrangement of the load hubs can be implemented in accordance with Article 2.3.1 of the specification. When the bridge deck has four lanes and is designed for a four-train convoy, the vehicle load is reduced by 30%, but the reduced load shall not be less than the result calculated for a two-train convoy. When the bridge deck is wider than four lanes and is designed for a convoy of more than four trains, the reduction in vehicle load is the same as the four-lane rule. The influence of vehicle load (impact force, centrifugal force, braking force) can be calculated according to the relevant provisions of the current "General Specifications for Highway Bridge Design": (2) Verification load (crawler vehicle, flatbed trailer); the verification load is divided into the following according to the current "General Specifications for Highway Bridge Design": crawler - 50; trailer - 80; trailer - 100; trailer - 120, and its gravity is calculated according to the regulations. (3) Special loads: When a flatbed trailer with a load greater than the trailer load specified in the current General Specifications for Design of Highway Bridges and Culverts crosses the bridge, the following special loads may be selected according to the specific situation: ① 1600kN (160t) special flatbed trailer load ② 2200kN (220t) special flatbed trailer load; ③ 3000kN (300t) special flatbed trailer load; ① 4200kN (420t) special flatbed trailer load. The above four special flatbed trailer loads are arranged as shown in Figure 4.1.1, with the front being the rate-guided trailer and the rear being the loaded heavy vehicle. The main technical indicators of special flatbed trailers are shown in Table 4.1.1.
Z50kN 150kN 150
[251 [s]] [] [ze] (85]
+6 +s+
Trailer longitudinal bracing
(a) Special flat-bed trailer—160
264hH TkN
457515+151.3 4s1875
Trailer longitudinal arrangement
(b) Special flatbed trailer—220
Jan 2g
Trailer transverse bracing
Trailer transverse arrangement
4—8-5
IeTN H47hN
[14. Ft14. .
Longitudinal arrangement of the front
Plane arrangement of the front
[e. 3t?Et an?
14kN I7N
[1t, (14. Ta]
Longitudinal arrangement of the front
[8.22,2,T28.8,
+5s5ss
Longitudinal arrangement of the shoe
（C）Special flatbed trailer—30 0
JIn JISIn SIBin SISin JISin IShn JIShn 3IBin JIBh JIh([[]
es a0s 0as s us
Trailer longitudinal support
(d) Special flatbed trailer—420
Front plane arrangement
0.9h1.31 0.9
Trailer directional arrangement
30 08 90 00
Transverse layout of trailer
kitchen 4, 1. 1 Special flatbed trailer—160.220.300. 4Z0 Note: In order to make the calculation method and control the weight of each axle of the vehicle to be the same, the sum of the weights is slightly different from the vehicle weight. The size is in meters. The main technical indicators of special flatbed carts
Main indicators
Sugar-sensitive weight
Flat-bed vehicle input number
Pressure on each axle
Each axle
Wheel level
Resolution rate
Degree and length of wheels on the ground
5 rows 10 contact
0.5 (g) ×
Special-200
Select 14 axles
1. 575+4×
1. 5+3. 575
0. 5(width)×
—-300
Table 4.1.1
—420
9 rows 18 axles 12 rows 24 transmission
0.5(width)×
0.5(）×
0. 2(length)
。 , 2(length)
0. 2(length) 0. 2(length)
Note: ① The bridge with intermediate design is the bridge deck with the structure connected as a whole. When the carriageway is a single lane (3. 5 ~ 4. 5m), the calculation of the replacement strategy is not specified. It shall be determined according to the actual situation during design.
4. 1. 2 When using the verification load calculation, the load can be arranged according to the following requirements: (1) Longitudinal arrangement:
When the track-50 of the current "General Specifications for the Design of Public Bridges" is adopted; multiple vehicles can be considered to travel in the same-direction occupied traffic lane, but the clear distance between the two vehicles shall not be less than 50m.
For various flatbed trailers (trailer 80, trailer-100, trailer-120), one vehicle is loaded in the occupied traffic lane in the middle direction according to the full length of the bridge, and there are no other vehicles in front and behind.
(2) Horizontal layout:
① For motor vehicle lanes or mixed traffic lanes without a median strip: When the carriageway is two or three lanes (the width of each lane is 3.5m to 3.75m, the same below), the load diagram should comply with Figure 4.1.2-1; when the carriageway is four lanes, the load diagram should comply with Figure 4.1.2-2, where (a) and (b) are calculated separately as needed.Choose the unfavorable one; 4---8--6
car or helpbzxZ.net
travel
two-lane~three-lane road design
Figure 4.1.2-1
towards, ① choose one of the flatbed control car and the last car, choose the unfavorable one. ②The size of the display is in m.
car
car
car
travel
car
travel
car
travel
wa-four-car spot slightly higher
Figure 4.1.2-2(a)
Note; ① choose one of the flatbed car and the rear car, choose the unfavorable one. The car is a standard car (excluding additional cars and impact), and can be measured as shown in the figure, or not measured. ③ The center size is in m,
travel in the acid surrounding
single car or hired car
travel in the commercial area
W,-National Highway Road Surface Research
Figure 4. 1. 2--2(b)
When the carriageway is six cars, its drug load diagram should comply with Figure 4. 1. 2~-3, among which (a) and (b) are calculated separately as needed, and the unfavorable one is taken. =The second judgment of automobile traffic risk range
Ie /03s 2+ +o
A Shun automobile
Traffic test limit
*One lane road width
Figure 4.1.2-3(a)
A traffic model
W and 16-year road improvement
Figure 4.1.2-3(b)
Note, (D) The standard vehicle and the standard vehicle are selected, and the vehicle is the standard vehicle (excluding the additional vehicle and the impact), and the vehicle can be connected as required, or not. @The size is in m.
② Design of motor vehicle lanes in the median strip: When the motor vehicle lanes on both sides of the median strip are two lanes, the load diagram should comply with Figure 4.1. 2—-4,
Jing Automobile
Traveling Song Model
Rate road can be directly
Figure 4. 1. 2—4
Note, ① Choose one of the flatbed control car and the skirt car, whichever is the least favorable. The delivery car
The pick-up car
Traveling silk Qing Wen Shu Guo system
②The Kang car is a standard car (excluding the weighted car and the impact), which can be arranged as shown in the figure or not according to the needs. @The size in the figure is in m.
When the motor vehicles on both sides of the median dividing strip are three lanes or wider, the load diagram should comply with Figure 4. 1. 2--5, where (a) and (b) are calculated separately according to the needs, whichever is the least favorable.
Type II Military Operation Intention
X≥Three-Rate Grass Road Time
I yess . o
One to share the car
Train style
Lianhe male three-lane road area
Figure 4. 1. 2-5 (a)
Three trains line sugar hard surrounding
μ2 three tables are variable
Figure 4. 1. 2-5(b)
Note; ① Choose one of the flatbed single car and the belt car, and take the unfavorable one. The car is the standard car (excluding straight cars and impact), and the three rows can be arranged according to the sales requirements, and any two rows can be arranged. Or any one row, or no row can be arranged
The mid-term size is in units of cut,
③ When there is a dividing strip between the non-motorized vehicle lane and the motor vehicle lane on the bridge deck, when calculating the load over the bridge, the non-motorized vehicle load on the non-motorized vehicle lane is calculated as 70%. 4. 1. 3 When using special flatbed trailers (Special-160, Special-200, Special-300, Special-420) for verification, the following requirements shall be followed.
(1) Longitudinal arrangement:
In the motor vehicle lane of the same width, the load shall be arranged as if one special flatbed trailer is running within the entire length of the bridge, and there shall be no other vehicle loads in front or behind. (2) Horizontal arrangement:
① For motor vehicle lanes without a central dividing strip or a bridge deck with a combined driving lane, when the motor vehicle lane is not more than two lanes, the load diagram shall comply with Figure 4.1.3-1. When the motor vehicle lane is more than two lanes, the load diagram shall comply with Figure 4.1.3-2. ② Motor vehicle lanes with median strips: When the motor vehicle lanes on both sides of the median strip are two lanes each, the load diagram shall comply with Figure 4.1.3--3;
When the motor vehicle lanes on both sides of the median strip are three lanes or wider each, the load diagram shall comply with Figure 4.1.3--4.
Transfer vehicle
Transfer vehicle
Special vehicle
Traffic specification.
W Two-lane road national g
Note that the dimensions in the figure are in m
List of automobile traffic specifications
Two-lane road width
Retention rate
Traffic missing range
>Two-lane road drawing
4. 1. 3--2
Note that the dimensions in the figure are in m.
Waiting for the express car
Holding the car lane width
Wa second lane cheese width
4. 1. 3--3
Note, ①The car is a standard car (excluding weighted cars and impacts), which can be measured as shown in the figure as needed, or ②The dimensions in the figure can be measured without measurement, and the unit is m2.
h.. h.3..
Automobile accident assistance
wm≥Three-lane road west
Change to controlled vehicle
3. 0 3. 0
Stop controlled vehicle and return payment
w_≥Three-rate town road west
Note; ①The car is a standard car (excluding weighted vehicles and impact), which can be arranged in a row as shown in the figure or not as required. ②The measurement is in m,
4. 1.4 When using tracked flatbed trailer for verification, impact is not taken into account, and crowd load and other live loads other than those specified in Article 4.1.2 of this Code are not always taken into account. When using special flatbed truck for verification, impact is not taken into account, and non-motor vehicle load, crowd load and other live loads other than those specified in Article 4.1.3 of this Code are not always taken into account. When the structure is designed by the allowable stress method, the design internal force is the maximum and minimum envelope value of the sum of various internal forces, and the allowable stress of the material is increased according to relevant regulations; when calculating according to the limit state, it should be calculated according to the load factor and design strength specified in relevant regulations.
4.1.5 The design vehicle load of urban bridges should be selected according to the specific conditions such as the nature of the use mission and development requirements of urban roads. The selection of design vehicle loads can refer to Table 4.1.5. Special flatbed trailer loads are only allowed to travel on designated routes in the city. 4-8—8
Urban bridge according to the design vehicle load frequency selection table—Urban road grade
Calculate load sensitivity
Check load age
Soon to come
Car—
(Trailer—100
Main road
[Car-20 grade
Trailer ·．[00
Secondary road
-15 grade
Xiang Yi 8
Car-~Super 20 grade
Business young about
Trailer 120
1Trailer 100
Table 4. 1. 5
Standard--15 Grade
Trailer—80
Note: The urban road grades listed in the table are classified according to the current (urban road design specifications). For branch roads in small cities, depending on the specific situation, it is also possible to consider using automobile-~10 grade, difficult road-~504. 1. 6
The design loads of non-motorized vehicle lanes and special non-motorized vehicle bridges on general road bridges shall be calculated in accordance with the following requirements;
(1) When there is no permanent (such as lined) separation strip between non-motorized vehicle lanes and motor vehicle lanes on the bridge deck, the crowd load on the non-motorized vehicle lane in accordance with Article 4.2.1 of this Code shall be used as the design load. In addition, the total width of the non-motorized vehicle lane and the motor vehicle lane after the combination shall be considered as the motor vehicle lane (based on motor vehicle load distribution), and the calculations shall be made separately, taking the less favorable one. (2) For non-motorized vehicle lanes and special non-motorized vehicle bridges with permanent separation strips between motor vehicle lanes and non-motorized vehicle lanes on the bridge deck, the calculations shall be made according to the following different situations! If the width is greater than 3m, in addition to taking the crowd load in Article 4.2.1 of this Code as the design load, the "10-level" standard vehicle (excluding weighted vehicles and impact) in the current "General Specifications for Design of Highway Bridges" shall be used as the design load, and the calculations shall be made separately, taking the less favorable one:
If the width is less than 3m, in addition to taking Article 4.2. In addition to the crowd load of Article 1 as the design load, a human labor vehicle (trolley) is used as the design load (refer to Figure 4.1.6) for calculation respectively, and the less favorable one is taken. 4.1.7 Design load of special pedestrian bridges
(1) Pedestrian bridges with conditions (slope and width) for motor vehicles shall be in accordance with Article 4.2 of this Code.2 as the design load, and then use the "Automobile-10" standard vehicle (excluding the added vehicle and impact) in the current "General Specifications for Design of Highway Bridges and Culverts" as the design load, and calculate separately, and take the less favorable one. (2) For pedestrian bridges with a height of less than 3m for non-motor vehicles, which cannot pass motor vehicles but can pass human labor vehicles (trolleys), in addition to the crowd load in Article 4.2.2 of this rule as the design load, one human labor vehicle (trolley) is used as the design load (according to Figure 4.1.6), and calculate separately, and take the less favorable one. (3) For pedestrian bridges that cannot pass motor vehicles and human labor vehicles, the crowd load in Article 4.2.2 of this rule is used as the design load. 4.2
People
The design crowd load for general urban bridges (not dedicated pedestrian bridges) shall comply with the following provisions:
(1) The crowd load for the sidewalk slab (fat component) shall be calculated separately as a vertical concentrated force of 5 kPa or 1.5 kN acting on one component, whichever is more unfavorable. (2) The crowd load W of beams, trusses, arches and other large structures shall be calculated using the following formula:
When the loading length L<20m:
W 4.5.20 =\ekPa
(4.2.1-1)
When the loading length 20m≤L≤100m (100m or more is the same as 100m): L - 20, (20 - wt) kPa (4.2.1--2)W = (4.5 - 2
The value of W shall not be less than 2. 4kPa. Wu Zhong: w
Crowd load per unit area, kPat
—Loading length, m
ul. …-Width of single-sidewalk, mi is 1/2 of the bridge width on a dedicated non-motorized vehicle bridge (when there is no sidewalk). When it is greater than 4m, it is still calculated as 4m. 4.2.2 The crowd load on a dedicated pedestrian bridge shall comply with the following provisions: (1) The sidewalk slab (local component) is the same as Article 4.2.1 (1) of this Code. (2) For beams, trusses, arches and other large-span structures, the following formula shall be used: When the loading length is 1.<20m:
W = 5 × 20 =\kPa
When the loading length is 20m≤1≤100m (above 100m to 100m): W = (5 2×
20)(20
(W value will not be less than 2.4kPa in any case) Where: w-
crowd load per unit area, kPa;
L-—loading length, m
(4.2.2-1)
W+)kPa (4.2.2--2)
half bridge width, m, when it is greater than 4m, it is still calculated as 4m. 4.2.3 The design live load on the safety lane (see Article 5.0.8 of this Code) is 2kPa or 1. A vertical concentrated load of 2+0.251
kN acts on small components of short spans. The loads are calculated separately and the less favorable one is taken. When calculating components connected to the safety lane (when vehicle loads or crowd loads are included), the live loads on the safety lane are not taken into account.
The live load acting on the handrails of the sidewalk on the bridge (only for calculating the handrails) is: vertical load 1.2kN/m; horizontal outward load 1kN/m. Both are considered separately (not acting at the same time).
Other loads and external forces
4.3.1 Other loads and external forces acting on urban bridges (wind force, water pressure, ice pressure, earthquake force, impact force of ships or source flow objects, temperature changes, influence of concrete shrinkage and creep, and bearing friction, etc.) can be implemented in accordance with the relevant provisions of the current "General Specifications for Design of Highway Bridges and Culverts".
4.4.1 The clearance limit of the bridge deck of a newly constructed bridge shall comply with the requirements of Figure 4.4.1. (1) Expressway bridges may be arranged according to Figure 4.4.1-2(b) or Figure 4.4.1-4(b). The median dividing strip wa of the expressway may be replaced by lines in super-large bridges and large bridges. However, a folded dividing strip or dividing fence must be set between the expressway and the non-motorized vehicle lane, and a guardrail should be installed if necessary. The width wt of the strip in the figure depends only on specific needs.
(2) The main trunk bridge may be arranged according to Figure 4.4.1-4, and the median dividing strip ea may also be replaced by lines, or it may be arranged according to Figure 4.4.1-3. (3) Secondary trunk bridges may be arranged according to Figure 4.4.1-1, Figure 4.4.13(a) or Figure 4.4.1-2(a), and the median dividing strip w may be replaced by lines. (4) For branch bridges, the layout may be in accordance with Figure 4.4.1-1. (5) For extra-large bridges and large bridges, except for expressway bridges, which meet the requirements of Article 5.0.5 of this Code, the layout of lanes may refer to Figure 4.4.1-1 or Figure 4.4.1-2, and the center dividing strip wm may be replaced by markings.
(b) with w;
4. 4. 1-1 Clearance limit without central dividing strip (one strip) wma+0. 25m
wmot0.25m
(b) with inclination W,
clearance limit with central dividing strip (two strips) 4. 4. 1-2 with—2
4—8--9
4. 4, 1-3 Clearance limit with one central dividing strip (two strips) 0.25
4. 4 1-4 Clearance limit with three or five dividing strips (four strips) Figure 4. 4-1 Clearance limit of bridge deck (continued)
The clear height H of the motor vehicle lane shall not be less than 4.5m according to driving requirements, and 5m may be used when trams are running.
The net height h of non-motorized vehicle lanes can be 3.5m. The net height of sidewalks should not be less than 2.5m. In the figure:
-Roadside strip width (m) 1
Non-motor vehicle lane width (m),
te'dme -
Motor vehicle lane width or motor vehicle and non-motor vehicle mixed lane width (m)
Two-side separation width (rm) t
-Central separation strip width (m);
Facility strip width (m)
Lateral clear width (m),
Non-motor vehicle road edge strip width (m);
Motor vehicle road edge strip width (m):
Pedestrian sidewalk width (m)
zpb-Non-motor vehicle road surface width (m)
~Motor vehicle road surface width or motor vehicle and non-motor vehicle mixed lane width (m),
-Two-side dividing grid width (m) :
1 Motor vehicle safety belt width (m) Middle dividing strip width (m) 1
H---- Clear height of motor vehicle lane (m).
Clear height of non-motor vehicle lane (rn).
4—8--10
Design of bridge deck in plane and longitudinal and transverse sections
3.0.1 Urban bridges should be made into straight bridges in plane. In special cases, they can be made into curved bridges. Their linear layout should comply with the provisions of the current "Regional Urban Road Design Code". $.0.2 The main beams, main trusses or arch ribs of bottom-through and mid-through bridges and the plains and towers of suspension bridges and cable-stayed bridges can be set on the sidewalk or on the lane divider, but protective measures must be taken to ensure that vehicles will not hit them under any circumstances. The decks and towers of the case and cable-stayed bridges can also be set outside the sidewalk railings. 5.3 The width of the carriageway on the bridge deck should be arranged in a way that is consistent with the carriageway width of the road it connects to. When the existing road section is very different from the planned section and it is very difficult to build the bridge according to the planned lanes, Article 2.0.2 of this standard should be followed. If the roads at both ends are equipped with wider dividing strips or green belts, the bridge can be constructed in parts (transversely as a separated bridge), or replaced with general dividing strips or lines. Green belts should not be set up: the width between the curbs (pedestrian curbs) of small bridges should be equal to the width between the curbs of the two roads, so that the curbs are connected straight (the width of the bridge deck and lanes is not narrowed); the width of the carriageway of large and medium bridges can be the sum of the effective widths of the carriageways of the two roads at both ends (excluding the width of the dividing strips). In this case, a widened transition section should be set on the approach road to connect the two roads with the width of the pedestrian lanes on the bridge deck. In addition to the calculation based on the crowd flow, factors such as the surrounding environment should also be considered. Please refer to Table 5.0.3.
3.0.4 If large and medium bridges and the roads at both ends are newly built, the layout of the pedestrian lanes on the bridge should be based on the level of the planned road (refer to Section 4.4.1) and traffic flow. The width of each motor vehicle lane on the bridge: For large vehicles and mixed large and small vehicles, the speed is greater than or equal to 40km/h, the width of each lane is 3.75m; for vehicles with a speed less than 40km/h, the width of each lane is 3.50m. The width of each lane of the dedicated lane for small passenger cars is 3.50m. The width of the dedicated non-motor vehicle lane (based on the sense of bicycles) should not be less than 3.00m. Table of bridge sidewalks. Bridge nest level and terrain. Railway stations, terminals, long-distance bus stations, and other pedestrian-intensive areas. Large stores and large public cultural institutions. Commercial areas. General streets. Large bridges and super-large bridges. Sidewalks (single example) Table 5. 0. 3
When the section of a super-large bridge or a large bridge has one of the following conditions, motor vehicles and non-motor vehicles can be considered as mixed driving:
(1) The average traffic volume of each lane is less than 300 vehicles/h (equivalent to a small passenger car); (2) The peak hourly traffic volume of motor vehicles and non-motor vehicles in the same direction is not at the same time; (3) The peak traffic flow in both directions is not at the same time; (4) The traffic volume of motor vehicles and non-motor vehicles at one time is quite different; (5) The design speed of motor vehicles is less than 30km/hl; (6) The lanes connected at both ends are designed to be mixed lanes. Their width should be calculated according to the relevant provisions of the current "Urban Road Design Code". 5.0.6 The longitudinal section of the centerline of the bridge deck can have a flat slope, a slope break and a vertical curve. The vertical curves of the bridge deck on super-large bridges, large bridges and expressways should be arranged according to the relevant vertical curve provisions in the current "Urban Road Design Code".
For multi-span medium and small bridges, if prefabricated beams are used, the vertical curve can be replaced by a Huizhai line. However, at the convex intersection where the longitudinal slope becomes heavier, the algebraic difference between the two slopes should not exceed 0.5% for trunk road bridges and 1% for secondary trunk road and branch road bridges.
When designing the longitudinal section of a bridge, the influence of component bending and pier and platform settlement under long-term load should be considered.
5.0.7 In plain areas, when the longitudinal slope of the two roads is very small, the longitudinal slope on the bridge should not exceed 4% for motor vehicle lanes; it should not exceed 2.5~3% when motor vehicles and non-motor vehicles are mixed. If the non-motor vehicle traffic is large, the longitudinal slope should not exceed 2.5%. When the longitudinal slope and slope section length of the roads at both ends of the bridge in mountainous cities are large, the longitudinal slope and slope section length of the bridge deck can be increased, but should not be greater than the longitudinal slope and slope section length of the two roads. 5.0.8 Bridge deck cross-section layout:
(1) Pedestrian railings must be installed on the outside of the pedestrian walkway or safety lane of the bridge, and the height can be 1.0~1.2m.
(2) For expressway, trunk road and secondary trunk road bridges, whether with or without non-motorized vehicle lanes, if there are no pedestrians on both sides, safety lanes with a width of 0.50~0.75m should be installed on both sides. (3) Except for expressway bridges, for bridges with permanent separation of motor vehicle lanes and non-motorized vehicle lanes on the bridge deck or special non-motorized vehicle bridges, the sidewalks or safety lanes on both sides can be connected with the curbs 0.15~0.20m higher than the carriageway
(4) For trunk road, secondary trunk road and branch road bridges, when the bridge deck is a mixed traffic lane or a special motor vehicle bridge, the height of the curb of the entrance lane or safety lane above the carriageway can be 0.25~0.40m. If the bridge crosses a rapid, a large river, a deep valley, an important road, a railway, a main waterway, or the bridge deck is often covered with snow or ice, the curb height should be a larger value. Use reinforced railings on the outside. (5) Expressway bridge: If there is a non-motorized vehicle lane, the curb height of the pedestrian or safety lane on both sides can be 0.25~0.40m, and reinforced railings are used on the outside. If there is no non-motorized vehicle lane, the curb height of the pedestrian or safety lane on both sides should be 0.40m, and guardrails must be added at the curb. The net width between the guardrail and the outer railing on the safety lane is 0.75m. Note: Safety lane is only for temporary, maintenance, and repair personnel, and is not open to general pedestrian use.
5. 0.9 The bridge deck carriageway should be set with a cross slope to facilitate rapid drainage. =The horizontal slope on the bridges of expressways and trunk roads is 2%; the horizontal slope on the bridges of secondary trunk roads and branch roads is 1.5%~2% + The horizontal slope of the fire lane should be 1% of the one-way oblique lane. A sufficient number of drainage holes should be set beside the road stones.
The longitudinal slope of the drainage holes must not be less than 0.3%~0.5%. 6
Bridge approaches and approach bridges
6.0.1 The approach of the bridge should be laid out in accordance with the current urban road design specifications: the approach bridge should be laid out in accordance with the requirements of the bridge.
6.0.2 When laying out the approach of the bridge and the approach bridge, attention should be paid to the impact on the traffic of the blocks on both sides, especially to ensure the access of fire fighting, emergency rescue and other vehicles. When the bridge approach is a fill road, the impact of the foundation settlement caused by the fill on the nearby buildings and underground pipelines, especially the impact on the water supply and drainage pipelines, should be considered.
The approach bridge should also pay attention to the impact of its foundation settlement on the adjacent shelters, and the impact of the construction on the nearby permanent buildings must be considered. On the approach of the bridge with a large longitudinal slope, it is not advisable to set up level crossings, public transportation vehicle stops, and factory and neighborhood entrances and exits. A flat slope transition section of appropriate length should be maintained between the starting (ending) point of the longitudinal slope of the approach and the level crossing.
6. 6. 3 If there are wide green banks or separations on the two sides of the super-large, large and medium bridges, and the bridge deck is arranged according to Articles 5.0 and 3. of this Code, the sudden change of the sidewalk curb should be avoided at the bridge head. The curbstone should be provided with a smooth transition section on the plane, and its change slope should not be less than 6:1 in the length direction; width direction), and the corners should be connected with appropriate flat curves. 6.0.4 When the approach is filled with earth and high retaining walls are used on both sides, railings should be set on both sides. The layout can refer to the relevant provisions of Article 5.0.8 of this standard. 7. Detailed structure and attached facilities
7.0.1 Bridge deck pavement can be made of cement concrete or asphalt concrete. The strength grade of cement concrete should not be lower than No. 30. Cement concrete auxiliary equipment is not included in the load-bearing part of the structure. Only when the concrete auxiliary equipment and the bridge deck concrete are poured at the same time as the whole, and arranged according to the requirements of the combined structure, can it be considered as the load-bearing part. When the pavement thickness is included, 2cm must be subtracted (as a storage layer). The water-mixed concrete pavement layer on the prefabricated components needs to be equipped with a certain amount of steel mesh. When the bridge deck adopts a flexible waterproof layer (using coiled materials), a steel mesh should be set in the cement concrete pavement layer (protective layer) on it. 7.0.2 Whether the reinforced concrete bridge deck is equipped with a waterproof layer depends on the type of bridge structure: if the bridge deck system produces negative moment (cantilever beam, continuous beam, steel frame, continuous plate and large cantilever plate, etc.), and the top surface of the bridge deck produces tensile stress, then the entire bridge deck (including the carriageway and pedestrian part) must be equipped with a flexible waterproof layer. If the upper structure is a bidirectional prestressed concrete structure, under the design load, the upper edge of the main beam and the upper edge of the bridge deck (longitudinal and transverse) do not produce tensile stress, then only auxiliary equipment can be provided without an additional waterproof layer. For steel beams with reinforced concrete bridge decks, the entire bridge deck should be equipped with a flexible waterproof layer. The flexible waterproof layer can be made of a material saturated with asphalt, and 3 to 4 layers of asphalt are pasted layer by layer.
The back of the side wall and the top of the arch of a solid arch bridge need to be provided with a waterproof layer. However, if the bridge deck is paved with asphalt concrete or cement concrete and has drainage measures that meet the requirements, the back of the side wall and the top of the arch ring do not need to be provided with a waterproof layer. 7.0.4. For abutments with soil function (lightweight abutments and gravity abutments, etc.), the embankment of the approach road behind the abutment should be made of black road surface or cement concrete surface, and its length should not be less than four times the height of the bridge body. If the road surface immediately adjacent to the abutment is a dirt road, gravel road, or is high-grade but has a relatively tangible zone or dirt road, a viscous soil layer should be provided under the dirt road surface, gravel road surface, green belt or dirt road as a waterproof layer (between the sides and the slope behind the abutment), and its length should be three times the height of the abutment body, so that ground seepage will never flow into the abutment. 7.0.5 The transverse slope of the bridge deck shall comply with the provisions of Article 5.0.9 of this Code, and drainage holes (with curtains on top) shall be set at appropriate intervals on both sides of the vehicle. On the enzyme river bridge, the drainage pipe can be connected under the drainage hole to directly drain water into the river, but the lower end of the pipe must extend out of the bottom of the beam. The drainage pipe should be made of a solid material with good corrosion resistance. The pipe diameter should be 15ctmn, with a minimum of 4-8-11
10cm, and laid close to the curb. For overpasses with a short deck and sufficient longitudinal slope, when the longitudinal slope of the bridge deck is used to drain the water on the bridge surface at the curb to the drainage outlet near the bridge head, the bridge may not be equipped with drainage holes. If drainage holes are set on the bridge deck of a flying bridge, a gutter is set under the hole to connect to the downpipe, and connected to the regional drainage system along the pier (or platform). If the bridge deck is lower than the approach, measures should be taken to prevent water from the approach from flowing onto the bridge deck. The detailed arrangement of bridge deck drainage should ensure that no part of the bridge structure is eroded by the drainage system and its leakage water.
7.0.6 Bridge deck expansion and contraction continued,It should be able to adapt to the angle change after the bridge is free and loaded, so that vehicles can pass smoothly.
Expansion joints should be made of durable, non-slip materials and structures that are easy to repair and replace.
Continuous bridge decks can be used between multi-span simply supported beams to reduce expansion joints. 7.0.7 Beam bridges can select different supports according to their span, temperature deformation length and support reaction force:
For spans or temperature deformation lengths within 10m, multi-layer roll materials (such as asphalt felt) can be used for padding or rubber sheets of about 1cm can be used to replace the supports; for spans of 10-15m, arc-shaped tangent steel supports or plate rubber supports can be used; for spans of 15-30m, arc-shaped steel supports can be used for hinged supports, and movable supports can be used for saddles, or both can be plate rubber supports. When the span or temperature deformation length is larger, plate rubber supports, pot supports or spherical supports can be used according to the reaction force.
All types of bearings should be easy to inspect and maintain (including rust prevention, oiling, and removal of debris and garbage). If necessary, replacement should be convenient and reduce the impact on traffic. Steel bearings should be protected from rainwater erosion from the expansion joint.
All types of bearings, especially plate-type rubber bearings, should be horizontally expanded regardless of the upper structural corrugation (the contact surface between the bottom of the beam, piers, and platforms and the bearings should be horizontal). 7.0.8 When lighting poles or tram overhead wire poles are installed on the bridge: if the clear width of the sidewalk is less than 1.5, the poles or wire poles should be placed at the outer side of the sidewalk. When the clear width of the sidewalk is greater than 1.5tm, the poles and wire poles can be placed at the sidewalk near the stone, or in the dividing strip. The net distance between the edge of the pole seat and the road surface (kerbstone) shall not be less than 0.25m. 7.0.9 The lighting standard on the bridge shall be higher than that on the two roads. The road lighting standard shall comply with the relevant provisions of the current "Urban Road Design Code". 7.0.10 The pipelines installed in accordance with Article 2.0.8 of this Code shall be arranged in accordance with the following requirements: (1) Avoid installing them on the bridge facade to avoid obstructing the appearance. (2) They should not be installed under the motor vehicle. (3) Arrange the pipelines in a proper manner and ensure that they will not damage the bridge surface during installation, maintenance and repair. (4) The installations and pipelines shall not enter the clearance limit of the bridge deck and the navigation clearance under the bridge. 8.1.1 Urban interchange projects shall be designed in accordance with the overall requirements of urban planning and the provisions of the "Urban Road Design Code".
After deciding to build a grade separation, the layout of the interchange and the selection of the grade separation structure (overpass or underpass) should be comprehensively analyzed according to the following points: (1) Grade separation should be built once according to the plan, and the secondary part and the part that is not needed in the near future can be built in stages under special circumstances; (2) The land occupied by the project and the demolition of houses should be reduced; (3) The traffic relationship between the two sections should be properly handled - solve the traffic problems caused by the difficulty of grade separation in the nearby areas
(4) Pay attention to the architectural shape of the grade separation structure and the landscape treatment. When analyzing the use of space, possible interference with traffic should be avoided. Pay attention to the special requirements for the location of the platform; (5) When deciding whether to use an overpass or underpass structure for a grade separation, it is necessary to closely consider the terrain, landforms, geology, groundwater conditions and underground engineering facilities; (6) The relocation arrangements for existing above-ground and underground pipelines should be properly resolved; 4-8-12
(7) The impact of the construction technology used in the design on the surrounding buildings and existing traffic should be considered,
(8) The impact of the planned new buildings on the overpass project should be considered. 8.1.3 The plane, longitudinal and cross-sectional designs of grade separations should meet the following requirements: (1) The plane layout should be consistent with the technical standards of the roads it connects to meet the driving needs of the roads in the overpass area:
(2) The longitudinal section design should be consistent with the technical standards of the roads it connects to, and the appropriate longitudinal slope value should be selected in combination with local climatic conditions, vehicle types and slope capacity. The lowest point of the vertical curve should not be located in the tunnel (covered section). (3) The cross-section design should be consistent with the technical standards of the road it connects to. A separation strip can be set between the motor vehicle lane and the non-motor vehicle lane to ease traffic. (4) The layout of various poles, columns, and overhead wire networks in the grade separation section should pay attention to keeping the section clean and open. The same as Article 7.0.8 for overpasses. The poles and columns of the tunnel approach should be set on the separation strip or outside the road width. The horizontal spacing of the poles and columns in the interchange section should be roughly the same as the horizontal spacing of the poles and columns in the connected road. (5) For overpasses, pedestrian escalators should generally be set between the upper and lower levels of the tunnel. The location, quantity, and purpose (for general pedestrians or for management and maintenance personnel) can be determined according to the needs of the traffic organization of the interchange section. The form and shape should be included in the overall design. 8.1.4 The underpass of a grade separation (the road under a tunnel or overpass) shall meet the following requirements for the required safety belt width (the density from the outer side of the motor vehicle avoidance belt to the surface of the pier, platform and wall) and the requirements for the pier, platform and wall close to it. (1) When the underpass is close to a column or thin-walled pier, platform and wall, a guardrail shall be installed to protect the column, pier, platform and wall. The guardrail shall be independently supported, facing the motor vehicle lane, and its surface shall be at least 0.60m away from the outer side of the curb and at least 0.60m away from the surface of the column, pier, platform and wall. ① When the underpass is an expressway, main road or secondary road, the guardrail may not be installed if its safety skirt width is greater than 7m.
② When the underpass is a branch road, the required safety belt width for motor vehicles shall not be less than 0.50m, and the guardrail may not be installed.
(2) When crossing an intersection and leaning against a solid pier, platform or wall (such as a large-volume building): the required safety belt width for motor vehicles on expressways, main roads and secondary roads shall not be less than 0.60 mm: the compensation shall not be less than 0.40 m.
(3) The outer side of the non-motorized vehicle road under the intersection shall be no less than 0.25 m from the surface of the column, pier, platform or wall.
(4) If a safety lane with a width of 0.50~0.75 m is provided between the outer side of the curb of the crossing and the column, pier, platform or wall, when the rain is greater than the required safety belt, no safety belt may be provided.
8.2 Wire bridge
Under the wire bridge, it is strictly forbidden to have factories and workshops that produce flammable, explosive and toxic gases and other dangerous goods. 8.2.1
The warehouses that store such dangerous goods are strictly prohibited; if there are any facilities for the above-mentioned dangerous goods nearby, they should be kept at a certain safe distance from the bridge on the plane. When the distance is close, safety protection measures should be taken.
8. 2. 2 When the overpass crosses the railway line where the Yanqi locomotive is running, a smoke board should be installed at the bottom of the upper structure of the overpass. The smoke board is located above the railway, and its center line should correspond to the center line of the railway. The length (i.e. the width direction of the railway line) is not less than 4m above each track. The two ends of the smoke board extend beyond the width of the bridge.
8. 2.3 When the overpass is less than 30m and the bridge width is large, the bridge piers can be column-type, and the number of columns should be small to facilitate visual transparency and avoid a sense of disorder. 8.3 Underground
8.3.1 In urban grade separations, the clearance of the road under the underpass is completely or mostly lower than the nearby ground. The net length from the opening to the opening of the structure through which the underpass passes is less than 50m or less than 10 times the net height. This is called an underpass.
The lighting requirements for underpasses should be higher than those for connecting roads. Underpasses do not require mechanical ventilation.
The load on the railway acting on the underpass shall be determined in accordance with the current "Technical Code for Railway Engineering". 8.3.3
The load on cars, trailers, non-motor vehicles and people used in underpasses shall be determined in accordance with the relevant provisions of this Code.5tm, the light pole cordon pole can be placed near the sidewalk stone or in the dividing strip. The net distance between the pole seat edge and the road surface (kerbstone) shall not be less than 0.25m. 7.0.9 The lighting standard on the bridge shall be higher than the lighting standard on the two roads. The road lighting standard shall comply with the relevant provisions of the current "Urban Road Design Code". 7.0.10 The various pipelines installed in accordance with Article 2.0.8 of this standard shall be arranged according to the following requirements:
(1) Avoid installing them on the bridge facade to avoid obstructing the appearance. (2) It is not advisable to install them under the motor vehicle.
(3) Arrange various pipelines in a proper manner and do not damage the bridge during installation, maintenance and repair.
(4) All facilities and pipelines shall not enter the clearance limit of the bridge deck and the navigation clearance under the bridge. 8
Grasscrossing - Overpass and Underpass
General Provisions
8.1.1 Urban interchange projects shall be designed in accordance with the overall requirements of urban planning and the provisions of the "Urban Road Design Code".
After deciding to build a grade-separated interchange, the layout of the interchange and the selection of the interchange structure (overpass or underpass) shall be comprehensively analyzed according to the following items: (1) Grade-separated interchanges should be built once according to the plan. Under special circumstances, the secondary parts and the parts that are not needed in the near future can be built in stages; (2) The land occupied by the project and the demolition of houses should be reduced; (3) The traffic relationship between the two areas should be properly handled - solve the traffic problems caused by the difficulty of interchanges in nearby areas
(4) Pay attention to the architectural shape of the interchange structure and the landscape treatment. When analyzing the use of space, possible interference with traffic should be avoided. Pay attention to the special requirements for the location of the platform; (5) When deciding whether to use an overpass or underpass structure for a grade separation, the terrain, landforms, geology, groundwater conditions and underground engineering facilities should be closely considered; (6) The relocation arrangements for existing above-ground and underground pipelines should be properly resolved; 4-8-12
(7) The impact of the construction technology used in the design on surrounding buildings and existing traffic should be considered,
(8) The impact of the planned new buildings on the overpass project should be considered. 8.1.3 The plane, longitudinal and cross-sectional designs of grade separations should meet the following requirements: (1) The plane layout should be consistent with the technical standards of the roads it connects to meet the driving needs of the roads in the overpass area:
(2) The longitudinal section design should be consistent with the technical standards of the roads it connects to, and the appropriate longitudinal slope value should be selected in combination with local climatic conditions, vehicle types and slope capacity. The lowest point of the vertical curve should not be located in the tunnel (covered section). (3) The cross-section design should be consistent with the technical standards of the road it connects to. A separation strip can be set between the motor vehicle lane and the non-motor vehicle lane to ease traffic. (4) The layout of various poles, columns, and overhead wire networks in the grade separation section should pay attention to keeping the section clean and open. The same as Article 7.0.8 for overpasses. The poles and columns of the tunnel approach should be set on the separation strip or outside the road width. The horizontal spacing of the poles and columns in the interchange section should be roughly the same as the horizontal spacing of the poles and columns in the connected road. (5) For overpasses, pedestrian escalators should generally be set between the upper and lower levels of the tunnel. The location, quantity, and purpose (for general pedestrians or for management and maintenance personnel) can be determined according to the needs of the traffic organization of the interchange section. The form and shape should be included in the overall design. 8.1.4 The underpass of a grade separation (the road under a tunnel or overpass) shall meet the following requirements for the required safety belt width (the density from the outer side of the motor vehicle avoidance belt to the surface of the pier, platform and wall) and the requirements for the pier, platform and wall close to it. (1) When the underpass is close to a column or thin-walled pier, platform and wall, a guardrail shall be installed to protect the column, pier, platform and wall. The guardrail shall be independently supported, facing the motor vehicle lane, and its surface shall be at least 0.60m away from the outer side of the curb and at least 0.60m away from the surface of the column, pier, platform and wall. ① When the underpass is an expressway, main road or secondary road, the guardrail may not be installed if its safety skirt width is greater than 7m.
② When the underpass is a branch road, the required safety belt width for motor vehicles sha
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.