What Are Steel Piles?
Steel piles are precast piles that are driven into the ground for load-carrying purposes. The load-carrying capacity of steel piles can go up to 100 tons per pile.
Steel piles are commonly used in foundations of large structures such as port harbors, bridge construction, retaining walls, cofferdams, pile foundations, and other areas where the ground is soft and thick in nature.
The main purpose of using steel piles in soft thick areas is because the hard start is only available at greater depth; hence piles are driven into grounds for better load carrying.
Types Of Steel Piles
There are four types of steel piles are there, which are as follows:
- Pipe Piles
- Screw Piles
- Disc Piles
1. H – Piles
These types of steel piles are efficient bearing piles with modern technology in the piling industry. Strong penetration of the piles into the base layer will result in high-impact forces and stresses. H piles can be very useful to sustain these high stress and force.
Rolled steel H- pile has a smaller cross-sectional area, making the soil displacement process easier with no additional process such as water jetting, coring, etc. These are most commonly used in rocky or hard strata areas.
Advantages Of H-Piles
- The requirement for storage space is very less when compared to other steel piles.
- The handling process of H-piles is Easy.
- This type of steel pile can perform both friction and compaction of piles.
- The Splicing process is easy.
- The soil displacement while driving H-piles is very less.
- H piles can be driven to a maximum depth of 100m.
- The h pile driving process can be done closer to the existing structure.
- H-piles are often used to construct retaining walls, cofferdams, bridges, etc.
2. Pipe Piles
The pipe pile is a type of steel pile that is circular. These piles are designed in such a way they can be driven into the ground, either capped or uncapped, and filled with a hardener such as concrete. These steel pipe piles act as friction or end-bearing piles.
There are two types of steel piles
- Open End Piles / Uncapped
- Closed-End Piles / Capped
Open End Piles / Uncapped
These steel piles are driven into the ground with an open end. During the penetration, the soil struck in the pipe is removed with water jetting and a compressed air process; after that, the hollow pipe is filled with concrete. Pipe piles are most commonly used in rock or hard strata.
Closed-End Piles / Capped
The pipe piles are capped or wielded on the driving end. Commonly a conical/cap made of steel or cast iron is welded on the driving end.
After driving the pile into the ground, required amount of concrete is poured into the pile. Usually, the thickness of the pile can range between 8mm to 12mm, and the dia of the pipe can range from 0.25mm to 1.2mm.
Advantages of Steel Pipe Piles
- Pipe piles offer more friction than other types of steel piles.
- Due to its cylindrical shape, the weight is equally distributed.
- These hollow pipe piles can be filled with concrete and reinforced with rebars to withstand the structure load.
3. Screw Piles
Screw piles consist of a cast iron or steel shaft with an outer diameter, which usually ranges from 15 to 30 cm and ends in a helix or helical base. The pile shaft can be hollow or solid, and the diameter of the screw at its base ranges from 45 cm to 150 cm.
The piles are immersed by screwing the rod into the ground using an electric motor. Screw piles work most efficiently on soft clay or loose sand.
In such terrain, piles are easy to place, and also, the large bearing area provided by the screws makes the best use of the low bearing capacity of the soil.
Advantages of Screw Piles
- Screw pile installation processes are easy, require fewer machines, and take less time.
- Faster installation process.
- Screw piles result in less carbon footprint.
- There is no need to remove soil from the site while driving screw piles.
- Screw piles can be installed close to existing structures.
- Screw piles can be easily removable when no longer needed.
4. Disc Steel Piles
The arrangement of disc steel piles is similar to the screw piles, Where disc steel piles are made of solid cast iron with a cast-iron disc attached at the base. This disc at the base helps to increase the bearing area of the pile.
Like screw piles, these are also suitable for use in soft or sandy soil areas, such as marines construction, etc. A hole is made at the bottom to facilitate the water jetting process when penetrating the pile into the ground.
Advantages Of Steel Piles
- Steel piles have the ability to penetrate the rocky and hard strata.
- Using steel piles in foundations offers more strength and durability for the structure.
- The amount of soil displacement during steel pile penetration is less.
- These types of piles can sustain rough handling.
- The bearing capacity of steel piles is more when compared to others.
Disadvantages Of Steel Piles
- The efficiency of steel piles is comparatively low as friction piles.
- Steel piles are not cost-efficient.
- Steel piles are vulnerable to severe damage from corrosion and electrolysis.
Q. How many types of steel piles are there, and what are those?
Ans – There are 4 types of steel piles are present, which as follows
- Screw Piles
- Disc Piles
- Pipe Piles
Q. How to protect steel piles from corrosion?
Ans – Steel is highly subjected to corrosion, so some of the below methods can be adopted to protect it from getting corroded.
1. Providing additional thickness to the steel pipe.
2. Remove any corrosive soil around the area.
3. Protecting steel piles by the concrete encasement.
4. Using the cathodic protection method, where a small slow current is allowed towards steel piles, slowing down the corrosion process.