State any four causes of settlement of structure and remedial measures for it. | Building Construction

The causes of settlement of structure are:- 

1. Uneven bearing capacity of soil at foundation level 

2. Different loads on different parts of foundation 

3. Varying ground water table height 

4. Compressible foundation soil 

5. Pockets of different type of soil under the foundation level 

6. Expansive soils such as black cotton soil  

7. Vibrations, if it is factory foundation, or a building very near to railway tracks 

8. Liquefaction during Earthquakes and floods 

9. Elastic compression, plastic flow or consolidation under static load 

10. Excessive expansion and contraction of swelling soils. 

Remedial measures:- 

  

i) Compaction of soil over the complete area at foundation level.

ii) Proper design so that large load difference does not exists on different parts of the foundation.

iii) Dewatering of foundations if ground water table interferes with construction of  foundation.

iv) Stabilization of soil foundation level if it is excessively compressible.

v) Proper investigation of soil strata by trial pits and borehole data

vi) Special type of foundations for expansive soils such as black cotton soil.