9 Top Box Girder Bridge Advantages and Disadvantages | Box Girder Gridge Design

9 Top Box Girder Bridge Advantages and Disadvantages | Box Girder Gridge Design

What Is Box Girder Bridge? | Box Girder Bridge Advantages and Disadvantages |Box Girder Bridge Design

What Is Box Girder Bridge?

A box girder bridge, also known as a box section bridge, is a bridge in which the main beams are made up of hollow box-shaped girders.

The box girder is often made of prestressed concrete, structural steel, or a steel-reinforced concrete composite. The box’s cross-section is typically rectangular or trapezoidal.

Box girder bridges are often utilized for highway flyovers and contemporary elevated light rail transport buildings.

Although a box girder bridge is often a type of beam bridge, they can also be found on cable-stayed and other bridges.

Box Girder Bridge Design

A Box girder bridge is a multi-span steel truss bridge/prestressed concrete characterized by a very large, hollow box-shaped steel beam that is used to span between two piers.

The Box girder bridge design consists of three sections: the main girder, the flanking beams and the deck.

The deck is constructed last but since it serves as the only part that will be visible from ground level it needs to be able to carry traffic loads.

The box girder construction method is fast and efficient to fabricate, easy to inspect and maintain. Therefore, it is widely used in the civil engineering field especially in the construction of box girder bridges.

Box girders can also be prefabricated in a fabrication yard before being transported and installed with cranes.

Steel box girders are typically built off-site and crane-lifted into place, with sections joined by bolting or welding.

 When a composite concrete bridge deck is used, it is frequently cast in place using temporary falsework supported by the steel girder.

Both types of bridges can be installed utilizing the incremental launching technique.

Gantry cranes are frequently employed in this approach to place fresh segments onto existing portions of the bridge until the bridge superstructure is completed.

Box Girder Bridge Advantages and Disadvantages

Box Girder Bridge Advantages

1. Comparative Lightweight

Box girder are the most common bridge used in construction, mainly for its lightweight, ductility and simplicity of fabrication.

The box girder is the concept that allows the transverse stability of a beam to be demonstrated without using any vertical supports.

Therefore, a box girder design can easily be achieved in many different configurations and with no bracing or tied-down members.

2. Cost effective

The construction of box girder bridges is relatively simple, compact and cheap to construct.

It is one the best choice for new bridges.

The box girders help to make the bridge more stiff, practically unconstrained and less penetrable.

3. Modular design

Box girder design is of modular nature and it can be easily expanded or contracted in different spans with just a few simple steps.

The cost effectiveness of a box girder is purely dependent on its length.

4. Versatile and can be used in many structures

They can be used to build almost any bridge because they can be customized or designed in any number of combinations.

They are commonly used in the building of new bridges and can also be used in rehabilitation of older bridges.

5. Can support a wide range of loads

Box girders can be designed to support a wide variety of traffic loads. It can support both light and heavy loads.

6. Aesthetics is another advantage of box girders

They are easily designed in any shapes, sizes and spans depending on the need and necessity.

Box girder bridges are often used to make an attractive appearance on roadways.

And it also looks like a simple structural system

7. Large span

The box girder bridge design offers a large number of potential solutions for bridge construction because they can span over longer distances than many other bridges.

Usually, the box girders are fabricated in standard sizes and can be tailored to fit very large spans.  Box girders are strong and durable and can withstand a significant amount of loads and forces.

8. Economical Design Advantages

The fabrication cost of a box girder is less expensive than other types of bridges. The cost difference can be about 10-20 percent.

9. Quality assurance

The box girder is simple in design and easy to assemble in the field. Therefore, it is quite easy to ensure that the bridge meets all the quality standards and expectations.

10. Long lasting bridges

This type of bridge is able to withstand the toughest climatic conditions as they have been built to be very strong.

They are designed to last for many years before requiring any major repair or refurbishment work.

Disadvantages of Box Girder Bridge

1. Installation require heavy machinery

The main disadvantage of box girder bridge is its overall weight. Because the box girders are very heavy, they can be difficult to lift and place into position.

It is not heavy in comparison to other bridges available. Therefore, it is possible to keep the structure in balance and avoid the possibility of collapse.

2. Possible corrosion of steel and concrete due to environments conditions.

The box girders are typically made of steel or high-strength concrete composite materials for increased strength and durability particularly in the marine environment, however are susceptible to corrosion of steel and concrete due to environments conditions

3.  Design Issues

There is a need for design improvement because of the complications and limitations for fabrication and installation.

4. Can be unstable against earthquakes

The box girder bridge if not designed well may not be earthquake resistant. As a result, they should be designed properly in order to be able to support possible earthquake forces in the construction of bridge design.

5.   Inefficiencies in logistics and transportation costs

Box girders are heavy in weight and often require cranes or special transportation trucks with a very large carrying capacity to move them.

This means that there is an increased cost involved when transporting the materials to site.

Box Girder Bridges FAQs

0. What Is Box Girder Bridge?

A box girder bridge is one in which the main beams are made out of girders shaped like a hollow box. The box girder is often made of prestressed concrete, structural steel, or a steel-reinforced concrete composite.

The box’s cross-section is typically rectangular or trapezoidal. Box girder bridges are often utilized for highway flyovers and contemporary elevated light rail transport buildings.

Although a box girder bridge is often a type of beam bridge, they can also be applied on cable-stayed bridges and other structures.

1. Why a box girder bridge is made hollow?

Box girder bridges are made hollow for a number of reasons. One reason is to minimize weight and provide reduced demands on the foundation.

Another reason is to reduce the dead load, a way to meet the requirements of the bridge for a live load.

A third reason for hollow box girder bridge is makes the bridge easier to assemble and can help the bridge to be constructed in less time.

2. How do box girder bridges withstand the pressure?

The primary purpose of a bridge is to allow people to cross valleys, rivers and mountains.

A box girders bridge has a balanced load distribution which provides more stability than the other forms of bridge building.

 The weight load in a horizontal direction provides resistance against the rail strain when there are strong winds or storms so that bridges don’t collapse.

3. What is the benefit of using box girder bridges?

If you want to build an efficient bridge to carry heavy weigh, then a box girder bridge is the best choice because they have heavy duty strength which can make sure that there is a stable and safe load carrying ability.

 Box girder bridges are also more attractive and beautiful than other forms of bridge. The precast concrete box girders can save building costs due to less material used in the structure.

4. How is box girder made?

A box girder is created by two web plates that are linked at both the top and bottom by a common flange.

The formed closed cell has substantially more torsional stiffness and strength than an open section, which is the most common justification for using a box girder construction.

The hollow box provided the deck with the increased stiffness of a truss while being easier to build and requiring less engineering precision—at the cost of extra material.

5. What are the advantages of concrete box girder bridges over other types?

The box girders are constructed by using cast pre-assembled sections which provide an easy and safe construction process.

A modern technique is being used to construct precast box girder bridges which can be installed quickly and easily.

The materials used in the construction for these box girder structures are very strong and durable, so that it will last for a long time.

6. How to build a box girder bridge?

A box girder bridge is constructed by using horizontal deck consisting of U beams. The precast sections are used in the construction of box girders which are pushed together on the site. T

he ends of the beams are joined by a conventional steel beam with a special support being provided at the end of the span

In order to improve the aesthetics and aesthetics, flooring and sides can be covered with concrete to prevent corrosion and rusting of steel and maintenance work.

7. What is a box girder bridge made of?

A box girder is constructed using a variety of manufacturing techniques including a number of reinforced and prestressed concrete and steel materials used in the construction. The main type of material used in the construction of box girders are concrete.

 Apart from iron, carbon, glass fiber, etc, steel is also being used in the construction of box girders to provide support for the deck.

8. What is the strength of box girder bridge?

The main purpose of a bridge is to allow people to cross valleys, rivers and mountains.

 By using horizontal elements of bridges for load distribution, the box girders provide resistance against the rail strain when there are strong winds or storms so that the bridges do not collapse.

So a box girder bridge has great carrying capacity because of its torsional stiffness more than other forms of bridge building.

9. Why box girder bridges are made of reinforced concrete?

A box girder bridge is used to carry heavy weight. The main purpose of a bridge is to allow people to cross valleys, rivers and mountains.

 A box girders bridge has a balanced load distribution which provides more stability than the other forms of bridge building.

The weight load in a horizontal direction provides resistance against the rail strain when there are strong winds or storms so that bridges don’t collapse.