Erosion

Erosion refers to the process of weathering and transporting the materials around the earth like soil and rock. The erosion force usually occurs by the wind, water and natural slopes or some chemicals like acid rain


Although the erosion process is from the nature but lately it has been increased because the wrong behaving of human in dealing with nature resources, these like deforestation and the huge industrial revolution



One of the main causes of erosion is the gravity effect, on edged or creep sloped areas, the particles leave its places from higher levels to lower land due to gravity. The obvious example for erosion caused by the force of water is the shores erosion, it happens because of the tides effect. On very huge scale, erosion can happen by the movement of crust (the outer layer of the earth), in this case, erosion is caused by Tectonic effects

Caissons

A caisson is a structure used in construction
particularly underwater projects like bridge or dam construction. It is constructed to provide a dry, protected environment for workers and
construction materials

The caisson is generally a box like structure with an open bottom and open top some times. The structure keeps water out of the construction area while its open bottom allows workers to place foundations and piers in the sea bed or riverbed. An open caisson can be used in shallow water; its open top allows light and air to enter from above the water line

  For deep-water construction, a pneumatic caisson has a closed top; pressurized air is  pumped in, and personnel enter and leave through an airlock. Both types have sharp inclined lower edge, which allows the caisson to be deeply embedded in the ground

Before putting the caisson in its place, engineers look for stable seabed like rock. But if they don’t find this layer they make artificial layer to  provide safety to the caisson. In pneumatic caissons, an airlock allows access to the chamber and the pressurized air flow must be constant to ensure regular air changes for the workers and prevent excessive inflow of mud or water at the base of the caisson

For getting out the consumed material and excavation ashes, the workers use muck tube connected to the surface. A crane at the surface removes the soil with a clam shell bucket

Know About Aerial Lift

The Duluth aerial lift bridge is located across the canal that is the main entry to the Duluth harbor from Lake Superior.it is a major landmark in the port city of Duluth, Minnesota

The design of this bridge was the winner design from John Alexander Low Waddell who drew up plans for vertically lift bridge. when Duluth residents dug through the narrow slit of land known as Minnesota Point to create a harbor at the head of the Great Lakes

As suitable as the shipping canal was for the city, it left citizens on the Point cut off from the mainland. In 1892 Duluth held a competition for a bridge design that would enable residents to cross without interrupting traffic in the shipping lane. The winning design came from  John Alexander Low Waddell who drew up plans for a high-rise vertical lift bridge which was the first of this type

But the Duluth project was cancelled before construction began and Waddell’s design was later built in Chicago. In 1905 Duluth finally built its bridge. When it was completed in 1905, the Aerial Bridge's gondola had a capacity of 60 short tons and could carry 350 people plus wagons, streetcars, or automobiles

The bridge can be raised to its full height in almost 3 minutes, and goes up 25 to 30 times daily during busy shipping season. The span is about 390 feet(120 m). As ships pass, there is a customary horn-blowing sequence which is copied back. Long-short-long-short means to raise the bridge, and Long-short-short is a friendly salute. Its language between the bridge and the coming ship

What Is Air Compressor?

The use of air compression for construction tools is very convenient because they  normally use the energy of compressed air as opposed to electricity. Of course, when using a pneumatic
power tool, you will need an air compressor

Most air compressors run on diesel, and basic maintenance checks should always be conducted before operation. The power of compressed air can be dangerous, and caution must always be taken when an air compressor is in use. There are strict safety rules to abide by when using pneumatic power tools

The air hose must be checked for cracks or holes, and if anything suspicious is found, the hose must be replaced immediately. Before you connect the air hose to the air compression outlet, open the valve. After doing this connect the tool’s hose to the outlet and then ensure that the hose is clear of any water or foreign objects before you connect the hose to the power tool

Air breakers are designed for general demolition, and are probably one of the most popular pneumatic power tools on the market. An air breaker will be used to break medium and hard materials such as concrete and  asphalt. Prior to operation of an air breaker, you must always  check that all parts are securely fastened

A rock drill is probably another popular pneumatic power tool you will come across if you are using an air compressor to power  your construction work. as example for that, the shotcrete application and also the soil nailing uses the air compressor power to drive the piles into the soil