Category Archives: Bridge

How are bridges built over water?

Bridges are one of the most important constructions of the modern civilization. It connects distant places with each other and people can easily travel from one place to another. We all have travelled by many bridges some time or the other. But, have we ever thought how the bridges are built over water?

Not only just the river banks are connected with bridges, but even two creeks or more creeks of the oceans are also connected with magnificent bridges. Building flyovers on the concrete roads is easier than building bridges over water. Here is something interesting and knowledgeable that will stun you about the advancement of modern civilization, power of construction and technology.

Factors associated with building bridges:

Before you go into how bridges are made, there are a few things that you need to keep in mind. The bridges over water can be of two types – the floating ones and the permanent ones. Quite obviously, the floating ones are not permanent and are used only temporarily. Hence, they do not need a foundation. But the permanent bridges need a foundation and for that there are three basic factors that need to be kept in mind. These are –

  • The condition of the site
  • The technical ability and engineering capacity of the contractor
  • The technology available in the country.

The first two factors are dependent on the engineers to measure. But, the factor of availability of technological support depends entirely on the construction equipment that is available. For that matter it must be mentioned that there are various types of construction equipment available in the market that are specially designed to support bridge construction.

Steps of constructing a bridge:

When bridges are built over large water bodies such as a very deep river or even the sea, the following steps are followed.

  • Constructing the Foundation:

 

In order to build the foundation, a bed is sunk inside the waterbed from the top. It is like a frame to the pillars that will hold the bridge in place. After that, a support pier is made with the help of rigs.

  • Construction of Cofferdam:

 

Around the support pier and rigs, a Cofferdam is made. It is a special type of wall that is created surrounding the foundation. Continuous pumping removes the water from inside. The area is completely dried out and then, the foundation is made.

  • Bringing everything together:

 

After the construction of the foundation, the support piers are either cast in the yard or cast in place. Sometimes, this process is done elsewhere and then, barges are used to bring everything together.

Once this is done, the gaps are joined with segments of concrete structure.

Sometimes, the segments are supported by huge suspension cables. As they are brought into position, they are stitched together. Though these are the most common methods of constructing a bridge, there are other methods as well that are followed to construct the bridges. Certainly, the methods that are followed for bridges in shallow water are different from that in the deep water.

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Heavy Equipment that builds bridges

In order to merge two cities or places that is divided by a huge mass of water, we make bridges. Bridges that are strong enough to carry the load of heavy vehicles and cars all running at the same time over it. In order to build something that needs to be so strong, one can easily imagine the kind of heavy equipment that were used to construct such a bridge. The kind of heavy equipment that one can see in a construction or a mining site may not be very useful when it comes to construction of bridges over the water but if we are building a bridge covering a small area that has more of land, then the utility of equipment like backhoe loaders or an excavator becomes essential.

Building a bridge requires deep study of the location and skilled men who can execute the work. An operator who has been working all his life operating machines in a construction site may not find this work as his cup of tea and may probably not even understand how to go ahead with a given task. It is because the kind of work he has been doing all his life is entirely different from the work that has been assigned to him.

Utility of an excavator:-

Heavy equipment like an excavator are ideally used for building bridges that does not have a huge water body beneath and it needs certain degree of excavation to be done. Excavators are usually required for building bridges. Simultaneously, it has the capability to pull out the dirt from one place and put it on the truck. Though an excavator may not be required while building bridges over a huge water body or perhaps its use is limited during the initial phase of the construction and then it is replaced by other heavy equipments.

Bulldozer is needed to level the roads:-

A bulldozer is primarily required at the time of building roads on the bridge. There are used to level the roads over the bridge. The roll of a bulldozer is also quite limited and not used extensively during the construction of a bridge.

Heavy crane bridge building machine:-

In order to build big bridges, you require huge cranes that will help to put the slabs on the face of the pillars. It is unimaginable to place those heavy slabs without the involvement of a heavy crane. These cranes are initially used to give a structure to the bridge and once the structure is formed, the slabs are placed over it with the help of these cranes. Unlike an excavator or a bulldozer which may have limited use, these cranes are extensively used during the construction of big or small bridges.

Since the making of two bridges are not the same, crane manufacturing companies have come up with different types of cranes required for the construction. Each type of crane is meant for constructing a specific kind of bridge. They comes in different shape and sizes and it varies depending upon the sort of bridge that needs to be constructed.

 

Excavator an Effective Heavy Equipment used in Demolition, Clearing and Grading

All construction sites need to undertake three activities in the development process which are considered to be quintessential. These three activities include Demolition, Clearing and Grading. With technology evolving drastically Excavators has proved to be reliable and effective heavy equipment in conducting the three activities of demolition, clearing and grading.

Demolition is the process of tearing-down of structure and buildings in a construction sites with the help of manually driving hydraulic equipment such as excavators.

Clearing is the process in which dirt, debris, vegetation cover and excessive materials are removed from the building site to make it conducive for development.

Grading involves construction work such as making improvements on roads, laying foundation for railways and land etc.

Excavator in Demolition Process

Excavators are used to collapse two stored buildings by a deterioration process. The plan is to involve destroying the building while controlling the method and direction the building collapses. The whole demolition task is undertaken by a project manager who decides where damage is essential to enable the building to be pulled out in the desired direction. The walls of the building are damaged at the foundation of the building, but this depends on the design of the structure which totally dictates the demolition process. Factors such as protection and cleaning activities are taken into considerations while demolishing that particular building.

Excavators with high reach demolition are more frequently used for collapsing lofty buildings since it is not suitable for explosive demolition. Excavators equipped with shear accessory are normally used to pull apart a structure made of steel. To bring dust under control fire hoses are used to sustain a demolition of a wet building. Hoses are used by the workers which are attached to lifts to increase height.

 

Big buildings may require the application of the wrecking balls which are found to be more effective against building material, but controlling the wrecking balls can be a complex task for the workers and a lot of time it is found to be less competent when compared to other demolition methods. Innovative methods make use of the revolving hydraulic shears as well as rock-breakers which are fixed to the excavators for the purpose of cutting and breaking through wood, solid and steel material. The application of shears becomes useful when flame cutting would become hazardous.

 

Excavator in Cleaning Process

 

Excavators provide housing and commercial land clearing services and removal of debris dirt. As we all know clearing the land of the construction site is one of the foremost steps for constructing our home and offices, so first of all you need to get rid of all dirt, debris and other excessive dust. With Excavators clearing becomes an easy task without consuming too much money and time.

Excavator in Grading process

Grading a construction site does not merely refer to pushing filth around. By grading the building site with the help of Excavator the contractors ensure the location is at the accurate level to guarantee proper flow of the water. Grading helps in making right base of the building.

How to construct a strong bridge?

Bruce Jackson once said – “Bridges become frames for looking at the world around us”. This statement is perhaps enough to turn one’s mind to the importance of constructing a strong bridge. A well- designed bridge should be able to withstand the wear and tear of time. It should stand erect to enable the passenger to overcome the physical hurdles that come in their way such as valley, river or roads. There are three questions of “what” involved in constructing a bridge:-

  1. What is the time limit of your bridge construction?
  2. What is the purpose of constructing the bridge?
  3. What is the span of this bridge?

Steps to start constructing a bridge

Are you ready to add a bridge to your residential /commercial area? If yes, then follow the following steps:-

  • The first thing you have to do is to seek permission from one of the governmental authority. The agencies such as Water Control Districts, Department of Environmental Regulation etc. are authorised to give such permissions.
  • Now set your budget. Your budget should be high enough to buy all the necessary elements require building that bridge.
  • Then, think why you are constructing the bridge. If it is for commercial development, then it should be constructed with an attractive design. For that, you can also refer to a professional engineer.
  • Now, determine the length of the bridge. For this, calculate the gap between bottom of the bridge and the high water rise. It should be 5-10 feet from the top of the bank. It should be wide enough to provide a smooth clearance.
  • Then at last, design your bridge by referring to Americans Association of State Highway and Transportation Officials.

Types of design in constructing a bridge

  • Arch Bridges:- Arch bridges have connections at the supports and the centre point of the arch. It permits the bridge to respond strongly to heavy stresses and loads.
  • Truss Bridges:- This type of bridge is composed of many smaller parts. They are mostly made of metals. This bridge has generally triangle-shaped structure.
  • Covered Bridges:- Here, the enclosing roof protects the bridge from all kinds of withering. Thus it elongates the life of the bridge.
  • Pratt Truss Bridges:- In this type of bridge, the middle-section has cross diagonal members. This enables the bridge to get a lighter structure. It is the most common type of truss bridges.
  • Warren Truss Bridges:- It has many isosceles or equilateral triangles to connect the top and bottom line.
  • Suspension Bridges:- Here, the deck is hung from wire-rope suspenders. It consists of a tied arch that prevents the drifting of its bearings.

However, many times we lack the perceiving to build beautiful yet strong bridges. So, we can start by building small bridges that are strong enough to carry us. After learning the skills properly and getting trained, we can start making bridges that is needed to make the nation look beautiful and work perfectly.

Top 10 Fantastic Types of Excavators

Excavators are heavy equipments used for mining, digging and moving bulky objects. There are different types of Excavators. Here are top 10 fantastic types of Excavators.

Compact Excavator-It is that type of excavator which is basically a wheel vehicle with backfill blade and boom swing that operates independently. It can weight approximately 0.7 to 8.5 tonnes. Its structure has three separate division .The first division is house second one is undercarriage and lastly the workgroup. The hydraulic motors assist in travel functions as well as rotating the vehicle.

Dragline Excavator-Dragline Excavator finds its application in civil engineering and mining of surfaces.

It his divided into two categories

The first categories are cranes which are used for lifting materials. It is heavy in size and is provided with winch drum situated at the front side which acts as a dragline.

The second category is relatively smaller than the first category and is used for civil engineering purposes like constructing roads, bridges, port etc. It is also used for cleaning ponds and canals as well as driving heap rigs.

Wheel Excavator-This type finds application in surface mining. It is very large in size. It has a large round wheel as it name suggests with an arrangement of scoops which help in its rotation. All the materials are carried away from the machine by the discharge boom.

Reclaimer– A Reclaimer is a type of excavator which is used for handling large objects and eliminating heaps of materials. Reclaimers move on a rail between stockpiles. They perform all the instructions with the help of a remote control. All the modern reclaimers functions automatically whereas the older reclaimers are operated manually.

Digger Excavators-Such Excavators are heavy equipments and also has three separate divisions which are house, undercarriage and workgroup. The house comprises of boom and sticks. The second division which is the undercarriage consists of wheels and tracks. It is operated by cables.

Dredging– This vessel is used for cleaning and collecting the sediments and silt deposits in the bottom of the seas or lakes and disposing them to another place. Dredging helps to keep the seas and lakes traversable which would have otherwise become swallow due to presence of silt deposits making the seas and rivers unsuitable for navigation.

Apart from this dredging is also used for making harbours and channels in the sea for accessibility of larger ships. Other uses of dredging include mining of ocean floor, mining of sea beaches that are badly eroded by gales, eradicating garbage and debris, land reclamation etc.

Steam Shovel-The first Steam Shovel was invented by William Otis in the year 1839.

This excavation type is a large machine powered by steam. It finds in application in moving soil and rock. Steam shovel has contributed heavily in public works which dates back to 19th century. This equipment finds its application in constructing rails, roads and canals. They are also used for digging canals, building roads and railways and for mining purposes.

 

Vacuum Excavator-Vacuum Excavator is a vehicle which is used mainly for removing debris on land that is heavy. It is also used for eliminating soil from hole. Its structure consists of a suction nozzle with two knobs which the operator holds with his hands to grip it. For cutting soil and sucking up debris it has a tooth situated at the end of the tube.

Trencher-This type of Excavator is used for mining trenches, deploying drainage. It comes in different sizes and models. There are four different  kinds of trenchers includes Micro Trencher, Portable Trencher, Chain Trencher, Wheel Trencher.

Slurry Wall Excavator– They are used in the construction of concrete walls in those areas which are situated close to ground water table to block the walls enclosing tunnels.