2024 - Construction and Architecture İdeas | Cad Blocks

Building Foundation; Raft Foundation System and Details

beam raft foundation

Raft Foundation; Also known as general foundation (often called Raft Foundation), it is a combined foundation type that covers the entire area of ​​the system that forms the foundation of the structure.

As a rule, the raft foundation system is used on grounds where the bearing capacity of the soil is low. The behavior of the raft foundation is similar to the behavior of the grid foundation system.

delete the base

Stresses applied to the ground; It gives greater load pressure in the column region that continues over the raft foundation, and less in the column-free regions in between.

So the area I shared with you above represents the dimensions of the raft foundation and the area painted in red represents the Column System.

raft foundation grid system


In addition to the columns here, there are beams that act as reinforcement. This Beam system connecting the columns to each other is; It is used to spread the pressure/load so that the stresses and loads between the intermediate areas of the raft foundation are equal on the soil.


There are different types used in many different situations such as connecting different types of beam systems, creating the Heel / Shoe system in the Raft Foundation, and creating the beam system within the main foundation as Hidden Beam.

Without confusing you too much, I will share with you the application of the Raft Foundation system and the projected visuals of the Reinforcement (Rebar) system included in it, respectively.

Beam Raft Foundation

From this raft foundation system; Friends, it is the system in which all columns are connected to each other withreinforced concrete beams that connect the columns coming out of the foundation.

The beams connecting the columns are applied with different methods. In some cases, this is connected to the beam system that appears directly on the foundation (as in the image below), and in some cases, this beam system is connected directly to the foundation by placing additional rebar.

beam raft foundation

For friends studying Architecture, we can go into a little more detail about the subject and Foundation Plan drawing; For the Raft Foundation / Beam Foundation system, you can view all the details such as Beam, Foundation, Naming, Foundation Section on the visual below in the Architectural project drawing

basic plan

While drawing the basic plan, the project above shows you all the details you need to do in the drawing. In addition, I want to write in bullet points.

  1. The location of the columns is shown and a Thick color / Reinforced Concrete scan is made.
  2. Rat foundation width; It must be drawn and applied 50 cm from the outermost columns.
  3. 30 width – 60 cm height 30 / 60 beam system is created to connect the columns together
  4. Numbering of beams: 
    For the ground floor: ZK 1 (30 / 60)
    For the Basement Floor: BK 1 (30 / 60) as BK1 – BK2 is numbered as 3 4 5.
  5. According to the column system that forms the structure axle drawing is made. (Article writing for this Axle Drawing a> You can see the details in the title)
  6. If the floor covering is covered; To indicate the slab in the plan drawing It is numbered as D1/h:15. You need to specify the “h” slab thickness here.
  7. Finally, A-A and B-B sections are drawn and a section drawing describing the Raft Foundation system is made on both sides of the project.

Straight Beam Raft Foundation

The logic of this foundation system is exactly the same as the beam raft foundation system, but! The beams are not visible and there are beams connecting the columns within the foundation. For your better understanding, I would like to share with you the 3D Foundation Detail drawing of an accurate foundation static project;

basic static beam radius

I am sharing the 3D version of the plan drawing with you below so that you can understand the difference that distinguishes this foundation system from the other. The beams are not visible in the picture because they are inside the foundation. In other words, the columns are connected to each other with hidden / invisible beams inside the foundation.

raft foundation system

The system I mentioned at the beginning of the article, which I call the Shoe / Heel system, is; In Static Projects, additions are made under columns of small size or in parts where the load on the column is high, within the scope of the static project example below.

raft foundation reinforcement system

I tried to share as much as I could the systems of the Raft Foundation system, 3D visualization of the static project example and All the details about the Raft Foundation application system

There may be incomplete or incorrect explanations in the article, in this case, as additional information, Friends who want to contribute to the article would be very grateful if they could contribute to the article by using the message panel below. It would be better.

on the subject

You can access the titles of my articles on similar topics through the links below;

  1. What is Raft Foundation? How to apply Raft Foundation?
  2. What is Singular (Individual) Foundation? Architectural and Static Plan Examples
  3. What is Sub-Basement? Substrate Application and Detailed Explanation
  4. What is a Construction Static Project? – Project Examples
  5. What is a Retaining Wall? How To

Related Articles

Back to top button