Construction Technology L3 Westmorland School

Question 1

Explain the advice you gave in respect of the defective wall.

Answer 1

The wall was on or near its centre of gravity, in imminent danger of sudden collapse.

Question 2

Explain the wall construction and why you considered it dangerous.

Answer 2

The wall is of English garden wall bond and was 330mm thick with a 425mm coping
stone. The front elevation is approximately 3.6m high. I used a 1.2m spirit level and steel tape to measure the deformation at approximately 160mm. The centre of gravity was approximately 165mm (330/2).

Question 3

Explain the advice you gave in respect of the temporary protection.

Answer 3

I advised them to close off the area and erect a Heras fence immediately.

I advised erecting a shoring scaffold to support the wall and prevent its collapse whilst a permanent solution was sought.

Question 4

Outline the options presented to the client to resolve the problem.

Answer 4

1. Construct new masonry buttresses off new bases at regular centres. To eliminate the deformation of the wall remove the freestanding element of the wall (approx. 1.4m) and rebuild.
2. Take down and rebuild / sheet pile
3. Erect gabion wall or precast retaining wall in front

Question 5

Explain the reasoned advice in terms of the form of construction you proposed.

Answer 5

1. Construct new masonry buttresses off new bases at regular centres. To eliminate the deformation of the wall remove the freestanding element of the wall (approx. 1.4m) and rebuild.
2. Take down and rebuild / sheet pile
3. Erect gabion wall or precast retaining wall in front

Both options 2 and 3 risked impacting housing development at the rear. Option 1 presented the least risk and would be the most cost-effective solution.

Question 6

What advice did you give in respect of the timescales for the completion of the works?