topic 6 Geo

Question 1

Describe the two main differences between a contiguous bored pile and a normal bored pile.

Answer 1

1. CBP requires more steel reinforcements than bored pile
2. CBP is subjected to lateral load and bored pile is subjected to vertical load.

Question 2

List the three main advantages of contiguous bored pile.

Answer 2

1. Improved water tightness
2. Adaptable to any irregular layout of the excavation site
3. Can be adapted to form part of the permanent structure
4. Less noise compared to driven pile

Question 3

Determine four factors affecting the choice of materials for filling and backfilling.

Answer 3

1.The material is not too wet, full of voids and liable to excessive shrinkage

2. The material contains appropriate texture or consistency such that it can be
   properly compacted.

3.The material is readily available.

4.The material is as hard as possible.

Question 4

State the effects of wet conditions to excavation work.

Answer 4

1. Difficult to trim the formation level accurately
2. Difficult to erect formwork / Earth Retaining Structure (ERS)
3. Increase in concrete’s water/cement ratio
4. Increase in lateral pressure on ERS
5. Bottom heaving of excavation