Pipe & Excavation Contracting Flashcards
What should be the angle of repose for compacted sharp sand?
33°
A reference stake has 13 ft. 8 in and f. 8 ft. 3. In written on it, what does the 13 ft 8 in mean?
That the reference stake is 13 ft 8 in from the center line.
What is the problem with excavation in narrow spaces?
You cannot easily add water necessary for wetting.
When installing a thrust block on a 8-in pipe carrying 100 PSI with a 45° fitting and the elbow bearing against sand, what is the thrust block surface area?
See Chart in pipe and excavation contracting. Page 197 figure 7-2.
Using chart in book:
4100 (thrust)÷ 1000 (estimating bearing load of soil)
What is the calculation for production trenching /moving dirt in a back hose set?
Volume of dirt in set ÷ dirt Moved per cycle = digging cycles per set
What do contour lines on a topographical map that form a closed loop represent?
A summit or depression
A 100% slope is the same as a?
45° angle
What is a cut sheet?
A form showing elevations, cuts, and horizontal distances to a fixed point.
What type of pipe is typical used to connect at the top of a water heater?
Type m. Copper pipe
What is the best method for hauling dirt over a long distance?
Self-loading scraper or loader and truck.
You are excavating an area 245 ft by 350 ft, the equipment can remove 100 yrd³ per hour. If you need 6 inches of gray cut off the whole area, how many hours would it take?
245x350 = area
85750÷2 = cubic feet because it’s only 6”
42875÷27 = conversion to cubic yards
1587.9629629629 ÷ 100yrds/hr = 15.88hrs
Coarse grained soils like gravel tend to withstand?
Saturation
What type of slope is indicated by contours lines that are closer at the peak of the slope than at the bottom?
Concave.
Indicates that the slope of the land is increasing as it gets towards the peak.
The best piece of vibratory compaction equipment in situation where you have a wide trench and no cross lines is:
Sheep’s foot roller
When positioning a trench box it is always centered over the pipe. To mean safety in the ditch, the maximum height above the pipe you should install the tricks box is:
5 ft.
What is a hub?
A small stake driven into the ground to identify some reference point
The optimum hourly production rate is 700 loose cubic yards when working in soil with a 35% swell factor. What is the adjusted production rate in bank convict yards?( Pipe)
519
Which statement is true about the impact of soil structure and density and the choice of compaction methods to Maximize production?
Course sand and gravel compact well with water and vibration
An advantage of nuclear compaction test compared to other methods is that?
It does not require the removal of soil samples from the site of the test.
The advantage of using an angle blade over a straight blade is to:
Side cast materials.
If an operator fails too lift, tilt, an angle, the blade of a dozer just right:
Most of the load is lost
To convert bank cubic yards you divide your cubic feet total by?
27
The level of underground water is called
Water table
The advantage of a u-blade over a semi u blade is it:
Holds more material
Before making a pass, what should the dozer be aligned with?
Blade dump area.
What is the best method for compacting sanding gravel?
Puddling and vibration
The best piece of equipment to strip material over a long distance is a:
Scraper
You are checking elevations in an excavated area. There are three stake sets called a, b, and c. This A stake is labeled 3 ft. 4. In, the bee stake is labeled 4 ft 10 inches and the c stake is labeled the 7 ft. 2. In. What is the difference between stake a and c?
3 ft. 10 in
It is virtually impossible to compact without adequate?
Moisture.
With salt fences, generally the maximum spacing between posts should be _____ and the post-depth should be at least ____.
6ft, 12in
