Consolidation: General Settlement & Consolidation

Question 1

What is settlement in soil mechanics?

Answer 1

Settlement is the compression of soil due to an applied load, leading to a reduction in volume.

Question 2

What are the two main types of settlement?

Answer 2

Primary (Direct) Consolidation – Rapid settlement due to water expulsion from pores.
Secondary Consolidation – Long-term settlement caused by creep and reorganization of soil particles.

Question 3

Why is settlement important in foundation design?

Answer 3

Uniform settlement is acceptable but may cause functional issues.
Differential settlement can lead to structural damage, cracking, and instability.

Question 4

What are the Bjerrum limits for structural damage due to settlement?

Answer 4

Distortion Ratio Effect
1/150 Structural damage in buildings
1/300 Cracks in walls, crane issues
1/500 Limit for crack-free buildings
1/600 Stress concentration in structures
1/700 Problems for sensitive machines