Plumbers NZ is New Zealand's largest online plumbing, gas and drainage resource. Plumbing exam help, plumbing news, directory and free quotes.
-
QUESTION 8
(a) The following drawing represents a drainage profile, showing lengths and grade between
fixed points. Answer the following questions from the information given.
PLEASE SEE PDF FOR IMAGE
(i) A drain is 26 metres long and is laid to a grade of 1.65%.
Calculate to three decimal places the fall between the head of the drain and the
access chamber. Show all working.
(ii) A drain is 31 metres long and is laid to a grade of 2.5%.
Calculate to three decimal places the fall between the access chamber and the sewer
connection. Show all working.
(iii) Calculate to three decimal places the total fall in metres from the head of the drain to
the sewer connection. Show all working.
(3 marks)
(b) An excavation for a trench is to be carried out.
The excavation is to be 185m long with a width of 350mm, a depth of 620mm at the top
end and 1.800m at the lower end.
Each truck has the capability to hold 4 cubic metres of excavated material.
Dumping fees are $185.00 per load or part load for each truck.
Allow for 350mm depth of granular base course material along the full length of the
excavation.
The cost of granular base course material is $21 per cubic metre.
(i) Calculate the quantity of soil to be removed. Show all working.
(ii) Calculate the total cost of dumping fees. Show all working.
(iii) Calculate how many cubic metres of granular base course material are required.
Show all working.
(iv) Calculate the cost of granular base course material. Show all working.
(v) Calculate the total cost of both excavation spoil removal and granular base course
material. Show all working.
(5 marks)
Total 8 mark