HOMEWORK

Problem 1

You are to design a 800' long sewer pipe that is to be placed in a trench.

Prepare an Excel table showing the design elevations every 100 feet.

Use stationing of 0+00 for the beginning, and 8+00 for the end.

Place the pipe at a gravity drainage slope of -2.5% towards station 8+00.

The invert elevation of the pipe at 0+00 is 6375.00'.

The pipe has an outside diameter of 1' and a wall thickness of 1".

Your design needs to include the following:

a) List the elevations for the top of the pipe for the plus stations (0+00, 1+00, 2+00,

3+00, 4+00, 5+00, 6+00, 7+00, and 8+00) *.

b) Calculate the invert elevation for the pipe at station 8+00.

*Note: Elevations for the top of the pipe are used to place leveling rods at those

stations and control the depth of the pipe during construction (since the bottom of the

pipe is then inaccessible).

Hint1: Make a sketch.

Hint2: A 3% gravity slope means -3' per 100' (as in "three per cent"). "3% " is not an

angle.

Hint3: For short distances (i.e., pipe diameter and wall thickness) ignore that the pipe is

on a slope. See below.

Ignore