Zhang Xigang, Yuan H
As one key passage cross Changjiang River on the important trunk road from Jiayin, Heilongjiang to Nanping, Fujian, Sutong Bridge, planned by the Ministry of Communications, has one important status in the highway transport networks of the nation and Jiangsu province.
Preliminary work of Sutong Bridge started from 1991, the project was initiated officially in June, 2001, preliminary design work fully commenced at the end of February, 2002, and preliminary design was approved by the Ministry of Communications in March, 2003. Technical design and construction drawing design fully started from February, 2003, and technical design for the main bridge was finished in January, 2004. According to the project schedule, all construction drawing designs were finished in phases from June, 2003 to July, 2004, passed examinations of experts which were organized by the Communication Department of Jiangsu Province authorized by the Ministry of Communications, and all were submit officially for construction.
Main Technical Standard
1. Highway grade: full-closed two-way six-lane expressway on plain and lightly undulate area.
2. Calculated speed of vehicle: 100km/h.
3. Design reference period for bridge structure: 100 years for main bridge, and 60 years for auxiliary bridge and approach bridge.
4. Load grade for vehicle: auto-grade of super 20, trailer-grade of 120.
5. Deck clearance and standard cross section: standard width of bridge: 34m.
6. Longitudinal slope:≤3％
7. Transverse slope: 2%
8. Seismic resistance standard: VI degrees for basic seismic intensity at bridge site, seismic resistance standard is shown in Table 2-1.
|Table 2-1 Seismic Resistance Standard for Sutong Bridge|
|Bridge||Probability of seismic resistance||Requirements of structural performance||Target of structural check|
P1: 10% in 100 yrs
(recurrence period of 950 yrs)
|Main structure under limit state of normal service||Main structure used for stress check|
P2: 4% in 100 yrs
(recurrence period of 2,450 yrs)
|Main structure under limit state of bearing capacity, controlling displacement or deformation||Main structure used for check of limit bearing capacity|
|Auxiliary and approach bridges||
P1: 10% in 50 yrs
(recurrence period of 475 yrs)
|Quake durability resistance of structure using||Or considering to use durability to check limit of bearing capacity; checking displacement and deformation, main structure used for checking limit of bearing capacity|
P2: 2% in 50 yrs
(recurrence period of 2,475 yrs)
|Controlling displacement or deformation||Checking displacement or deformation|
|Table 2-2 List of design water level for Sutong Bridge|
|Designed flood level for once-in-300-year (m)||Minimum designed navigation level for 98% assurance rate (m)||Maximum designed navigation level for once-in-20-year (m)|
|Table 2-3 List of navigation clearance and number of navigation spans|
|Name of navigation span||Type of channel||Typical ship||Navigation clearance (m)||Number of navigation span|
|Net width||Net height|
|Main navigation span||Single-span double-channel||
50,000-ton-level container ship (3,800TEU)
Perspective massive bulk barges fleet of 48,000-ton-level
|Auxiliary navigation span||Single-span single-channel||massive bulk barges fleet of 9,000-ton-level||220||24||2|
|Dedicated navigation span||Single-span double-channel||bulk ship of 7,000-ton-level||220||39||1|
|Upward span in flood season||Single-span single-channel||river ship of 1,000-ton-level||70||15||1|
|Table 2-4 Overall ship impact standard|
|Navigation span||Pier||Impact force (MN)|
|Transverse to bridge||Longitudinal to bridge|
|Main bridge||North span||Transition pier||11.9||6.0|
|Auxiliary pier of remote tower||13.2||6.6|
|Auxiliary pier of close tower||40.6||20.3|
|Main span||North tower’s pier||130.6||65.3|
|South tower’s pier||126.7||63.4|
|South span||Auxiliary pier of remote tower||40.6||20.3|
|Auxiliary pier of close tower||13.3||6.7|
|Continuous rigid bridge of auxiliary bridge||Main span||North main pier||41.2||20.6|
|South main pier||49.8||24.9|
|North approach bridge, continuous-girder bridge of auxiliary bridge (intermediate approach), south approach bridge||Piers of navigable span||2.33||1.165|