What is Steining thickness?

According to the book “Soil Mechanics and Foundation” by B.C. Punmia page 789, steining thickness is given by. t =D/2{1-√1-4r/ρD} ; t is thickness, D is Dia of well, r is unit skin friction, ρ is unit weight of concrete for steining.

What is the edge of the well called?

Sharp edge which is provided at the lower end of the well or open and pneumatic caisson for accelerating sinking operation is called cutting edge. It is made up of steel or it is made in R.C.C. Its angle to vertical is 30 and normally slope of 1 horizontal to 2 vertical given a better result.

What are well Foundation?

Well foundation is a type of deep foundation which is generally provided below the water level for bridges. Cassions or well have been in use for foundations of bridges and other structures since Roman and Mughal periods. The term ‘cassion’ is derived from the French word caisse which means box or chest.

What is the purpose of cutting edge in well Foundation?

The cutting edge should be sharp so as to penetrate into the soil and it should resist the various stresses caused by blows, boulders, blasting, etc. A sharp vertical edge is generally provided to the outside face of the caisson. Edge facilities the rate of sinking.

What is well Steining?

Well Steining: Steining is a wall or shall type of structure made up of RCC, and which helps to transfer the load to the curb. It serves as an enclosure for excavating the soil for the penetration of the foundation well.

Is code for well sinking?

The existing practice in India is to decide the thickness of well foundation based on the formula given by Indian Roads Congress Code (IRC:78-2014) which is based on the assumption that steining should be rigid and thickness of steining should be sufficient for self-sinking of well to reduce sinking efforts and to …

When would you use raft foundations?

They spread the load imposed by a number of columns or walls over the area of foundation, and can be considered to ‘float’ on the ground as a raft floats on water. They are suitable where: Floor areas are small and structural loadings are low, such as in one or two-storey domestic construction. A basement is required.

What are the advantages of well foundation?

Advantages Of Well Foundation The advantages of the well foundation are as follow, It can withstand large lateral loads and moments which occur in the case of bridge piers, abutments, towers, and tall chimneys. It can withstand the reaction of scouring due to its large cross-sectional area.

Why are caissons used?

A caisson foundation also called as pier foundation is a watertight retaining structure used as a bridge pier, in the construction of a concrete dam, or for the repair of ships. This is because caissons can be floated to the job site and sunk into place.

How does a floating foundation work?

A floating foundation consists of boxlike rigid structures set at such a depth below ground that the weight of the soil removed to place it equals the weight of the building; thus, once the building is completed, the soil under it will bear the same weight…

What is the deep well?

: a well in which the water level is at a depth exceeding 22 feet beyond which the ordinary suction pump does not operate satisfactorily.

Is 12070 free download?

IS 12070: Code of Practice for Design and Construction of Shallow Foundations on Rocks : Bureau of Indian Standards : Free Download, Borrow, and Streaming : Internet Archive.

What is the minimum thickness of a steining?

The recommended minimum thickness is 0.75 m. It is the wall of well & is built over a wedge shaped portion called well curb. The steining is designed such that it can be sunk under it own weight. The thickness should be sufficient so as to overcome skin friction developed during sinking by its own weight.

How tall should a steining be for a well Foundation?

The steining should be built in short height of 1.5 m initially and 3 m after a 6 m grip length is achieved. The verticality should be maintained. The aim of the well sinking is to sink the well vertically and at the correct position. The following precautions are to be taken as far as possible.

Can you use acid stain on vertical walls?

First, acid stain is a liquid like water. When staining walls or vertical surfaces, acid stain will run down easily, which means that you will need to spray lighter than you would on a horizontal surface. You will have to follow the spray with an applicator brush and brush in a circular motion to take any runs off of the wall as you go.

How to calculate the steining thickness of well / caisson foundation?

Using any of the formula, the thickness of steining wont come close to the thickness provided in the case studies i mentioned above. By using Jack-down method of well sinking, thickness will be reduced, but how to calculate the optimum thickness of well steining in case of jack-down method?