What are the Suitable Methods for Compacting Foundation Soils of Different Types?

In the previous posts, we published in last few weeks, we have discussed different methods of compaction and measure methods for it for foundation soils of both highway construction or for founding building structures. Now We will discuss suitability of different methods of compaction for different types of soils:

a. Soil having no cohesion(c=0) like sand, gravels

b. Soil that are fully cohesive(φ=0)like undrained silts or saturated clays

c. Both cohesive and cohesionless soil (c≠0, φ≠0). These soils are sometimes called c-Φ soils like clayey sand, sandy clay, silty sand.

Where
c=cohesion intercept
Φ=angle of shearing resistance



a. Soil having no cohesion:

For large thickness deposit

Vibroflotation, vibratory rollers, terra probe, compaction piles, explosive are suitable

For small thickness compaction

In the base course of small thickness, smooth-wheel rollers show good result.


b. Soil that are fully cohesive

Sheep-foot rollers are found effective in this type of soil. Pre-compression, the methods discussed in previous post, is also used successfully.

c. Both cohesive and cohesion soil

This is the most common soils that are found in most places of the world. The methods stated below are universal:

1. In all types of confined space, tempers are effective to compaction such soils

2. For all types of soil, pneumatic tyred rollers can be used successfully

3. A promising method, named pounding is also used in this purpose.