Geotechnical Engineering

I have confusion regarding proctor compaction test. As per Is code 2720: 8, soil sample used should be sieved through 19mm sieve.Then what is the relevance of 4.75mm sieve? Please clarify me regarding the soil sample and the usage of ...

Why we conduct soil penetration test in soil investigation?

What is swell pressure test of soil and it's laboratory procedure?

What are the soil tests required for a 3 storey building and the standards for each test?

How to measure loads and pressures on geotechnical structures?