Foundations in Railway Electrification | Side Bearing & Rolled Steel Joist Types

In an earlier article, I have described the railway line survey into two steps or stages that are marking of chainage and foundation.

Now, here we are going to study about the…

• how marking is done
• types of foundation, and their different marking procedure

Types of Foundations in Railway Electrification

Let’s first learn about the types of the mast which will further help us in the marking procedure.

If you remember, implantation is the distance from the center of the track to the center of the mast so generally, we are having four types of poles.

Out of these four poles, two of them are of open section mast and two of them are yard mast. Generally, it is called ‘Uprights‘.

In an open section, types of the mast are divided with their dimensions.

Types of Mast	Mast Dimension
B-175 and B-200	175x300mm and 200x300mm
RSJ or 8×6	200x150mm

Here, ‘B’ stands for side bearing. And ‘RSJ’ stands for rolled steel joist.

Other types of mast called upright are,

• Nu
• Ou
• Ru

We would discuss their marking in article yard foundations and rules.

So, when we need to do foundation for b-175 or B-200 we need to add 15 to the implantation for the center and in the case of RSJ.

We need to add 10 to the implantation. So, as we know there are several types of foundations.

Let’s talk in detail about the side bearing (B) orb type foundation in detail. This type is further divided into thirteen categories. Let’s discuss one of the commonly used foundations b-5.

Let’s imagine of cuboidal shape, now fir getting it excavated. There must be some dimensions that one needs to keep in mind.

• Length:. 0.80m
• Breadth: 1.60m
• Height: 1.90

Now being at the site, we need to instruct the labor to excavate for railway construction in such a manner and the case cess level is greater than 90, we can decrease the height by approximately 70% of the foundation should be down.

On that dimension basis, the site engineer calculates the volume, amount of cement bags required, the ratio of concrete: sand: cement, and other quality checks.

If we are working for the ease of railway, safety must be ensured. As we could harm several thousand of people traveling in a train if mast fell due to weak foundation.

In the next chapter, I will cite a side gravity foundation marking and quality checks the engineer must assure that the material must be of the prescribed quality by performing quality checks at the site.