Evercross Bridge
ASTM Steel Truss Bridge With Flexible Design For Railway Bridge And Highway Bridge
Introduction of the steel truss bridge:
A steel truss bridge is a type of bridge that uses a truss framework made of steel to support the load. The truss consists of a series of interconnected triangular units. The main components of a steel truss bridge include the chords (the top and bottom members of the truss) and the web members (diagonal and vertical members that connect the chords). These members work together to distribute the load, such as the weight of vehicles and pedestrians, across the bridge span.
Design Comparison
1. Geometric Configuration
Pratt Truss Bridge: The Pratt truss is characterized by vertical members and diagonal members that slope towards the center of the span. The presence of vertical members provides a more regular and rectilinear appearance. The diagonal members are typically in tension for most common loading conditions, and the vertical members are in compression.
Warren Truss Bridge: The Warren truss consists of a series of equilateral triangles.
2. Member Complexity
Pratt Truss Bridge: Has a more complex member arrangement with both vertical and diagonal members. The connection details need to account for the different force directions of these members. There are more members in a Pratt truss compared to a basic Warren truss of the same span, which can lead to more complex fabrication and construction processes.
(1) Main girder
It is the main load-bearing structure and bears vertical loads.
The main truss is composed of upper chord, lower chord and belly rod. The belly bar is divided into diagonal bar and vertical bar.
Nodes are divided into large nodes and small nodes.
Pitch refers to the distance between nodes.
(2) Bracing
1. Classification: longitudinal connection and horizontal connection.
2. Function: Connect the main truss, make the bridge span structure become a stable space structure that can withstand a variety of lateral loads.
3. The longitudinal connection system is divided into upper horizontal longitudinal connection system and lower horizontal longitudinal connection system. The main function is to withstand the transverse horizontal load, transverse wind, lateral rocking force and centrifugal force acting on the bridge span structure. In addition, the transverse support chord, reducing its free length outside the plane.
4. The transverse connection is divided into bridge frame and crosslink. The main function is to increase the torsional stiffness of steel girder. Properly adjust the uneven force of the two main stringer or two longitudinal links.
(3) Bridge deck system
1. Composition: the longitudinal beam, beam and the connection between the longitudinal beam.
2. Way of force transmission: the load first acts on the longitudinal beam, and then from the longitudinal beam to the beam, and then from the beam to the main truss.
(4) Bridge deck
The bridge deck is the part for vehicles and pedestrians to walk on. The form of the deck is similar to that of steel beam Bridges and combined beam bridges.
Geometric characteristics of the main truss:
Economy, simple structure, conducive to standardization and easy to manufacture and install.
The main truss categories:
Triangular truss: Triangular truss structure is simple, the design is fixed, easy to install and manufacture.
Diagonal bar truss:
Many bar specifications.
Many specifications and large internal force of the vertical rod.
All are large nodes.
The K-shaped truss:
The shear force of the same node is borne by two diagonal rods, which are small and short in section.
The bar has many specifications, many nodes, short intersections, and many crossbar beams and connections. For small and medium-sized spans, the structure is complex.
For large spans, the rods are short, light and suitable for mounting and dismounting Bridges.
Double-vented bar truss:
The same internode shear force is borne by two diagonal rods, which are small and short in section.
It is used for large span, short compression inclined rod, which is favorable for buckling stability.
The small section of the inclined rod makes the number of connecting pins on the joint plate less, and it is easy to arrange the joint.
Application of the steel truss bridge:
Steel truss bridges are widely used for various transportation purposes. They are suitable for both highway and railway crossings. Their high load - bearing capacity and ability to span relatively long distances make them ideal for crossing rivers, valleys, and other obstacles. In addition to transportation bridges, they can also be used for pedestrian bridges, especially in urban areas or scenic locations where an aesthetically pleasing design is desired. The modular nature of the truss also allows for easy customization and adaptation to different site requirements and traffic volumes.
Regular maintenance is essential to ensure the safety and longevity of a steel truss bridge. This includes inspections to check for signs of corrosion, fatigue, or damage to the steel members. Corrosion prevention is a major aspect of maintenance, and measures such as painting, galvanization, or cathodic protection are often employed. Additionally, any loose connections or damaged members need to be repaired or replaced promptly to maintain the integrity of the truss structure.
Evercross Steel Bridges Overview :
EVERCROSS STEEL BRIDGE SPECIFICATION | ||
EVERCROSS STEEL BRIDGE | Bailey bridge(Compact-200, Compact-100, LSB, PB100, China-321,BSB) Modular bridge( GWD, Delta, 450-type,etc), Truss Bridge,Warren bridge, Arch bridge, Plate bridge,Beam bridge,Box girder bridge, Suspension bridge,Cable-stayed bridge, Floating bridge,etc | |
DESIGN SPANS | 10M TO 300M Single span | |
CARRIAGE WAY | SINGLE LANE, DOUBLE LANES,MULTILANE,WALKWAY,ETC | |
LOADING CAPACITY | AASHTO HL93.HS15-44,HS20-44,HS25-44, BS5400 HA+20HB,HA+30HB, AS5100 Truck-T44, IRC 70R Class A/B, NATO STANAG MLC80/MLC110. Truck-60T,Trailer-80/100Ton,etc | |
STEEL GRADE | EN10025 S355JR S355J0/EN10219 S460J0/EN10113 S460N/BS4360 Grade 55C AS/NZS3678/3679/1163/Grade 350, ASTM A572/A572M GR50/GR65 GB1591 GB355B/C/D/460C,etc | |
CERTIFICATES | ISO9001, ISO14001,ISO45001,EN1090,CIDB,COC,PVOC,SONCAP,etc | |
WELDING | AWS D1.1/AWS D1.5 AS/NZS 1554 or equivalent | |
BOLTS | ISO898,AS/NZS1252,BS3692 or equivalent | |
GALVANIZATION CODE | ISO1461 AS/NZS 4680 ASTM-A123, BS1706 or equivalent |
Advantages of the steel truss bridge:
High Strength and Load - Bearing Capacity
Steel has a high tensile and compressive strength. In a steel truss bridge, the truss structure efficiently distributes the load throughout the members.
Durability
With proper maintenance, steel truss bridges can have a long service life. Steel is a durable material that can withstand various environmental conditions such as rain, wind, and temperature changes.
Design Flexibility
The truss design provides a great deal of flexibility in terms of both aesthetics and functionality. Engineers can choose from different truss configurations (e.g., Pratt, Howe, Warren, K - truss, etc.) depending on the specific requirements of the bridge, such as the span length, load - bearing capacity, and available construction materials.