Hello everyone,
In today's article, let's take a closer look at the picture below and what it represents.
Picture 1&2
In pictures 1 and 2, we can see a reinforced concrete structure undergoing sand filling. This is referred to as the filling of a raft foundation. This type of foundation is widely used in areas with low soil bearing capacity or in swampy regions. It's purpose is to avoid differential settlement of the building by distributing the structural loads evenly.
Here, there are several reasons why the foundation was filled with a sharp sand instead of laterite sand.
- Sharp sand allows water to drain quickly because it contains larger coarse particles and it prevents water retaintion which could lead to differential settlement of the foundation.
- Sharp sand, when well compacted, provides better interlocking resulting in stronger and and stable base for the foundation.
Picture 3 & 4
In the pictures below, you can see the plumber fixing plumbing pipes in the raft foundation. This is done after filling of the foundation to avoid blockage from particles. After which the soil will be watered and compacted.
Picture 5 & 6
In the pictures below, you can see compaction taking place. The compacting machine was used to run through the whole surface of the foundation.
