Take Rod Readings and Calculate Elevations Review Questions
Take Rod Readings and Calculate Elevations Review Questions
Review Questions
- Record the readings on the following rods:
C) D) (Imperial)
- With the telescope of the builder’s level positioned 1150 mm above the elevation of the bench mark, what figures on the rod should be brought into the line of sight to establish an elevation 2200 mm below the B.M?
- With the builder’s level set up 1270 mm over the B.M. (10 000 mm) and with a reading of 1602 mm obtained when the rod is placed upside down against a ceiling, what is the elevation of the ceiling?
- What is the elevation of the top of a footing if the reading 4394 mm is obtained when the rod is placed on top of the footing and the instrument is set up 356 mm above the B.M (10 000 mm)?
- With the instrument set 1478 mm above a B.M. (10 000 mm), what reading would be placed on the rod to establish a finish elevation of 9400 mm at the bottom of an excavation?
- With the builder’s level positioned 711 mm above the benchmark and a reading of 1097 mm is obtained when the rod is placed on a finish floor, what is the elevation of the finish floor if the B.M. is 10 000 mm?
- When the instrument is set up 1372 mm above a B.M. (10 000 mm), what is the elevation of the top of a column if the inverted rod reading is 3278 mm?
- Using the setup shown below in figure 66, calculate on the field book sheet the elevations of stations 1, 2, and 3.
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Station |
B.S. |
I.H. |
F.S. |
ELEV. |
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B.M. |
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- Using the diagram below, find the elevations of stations 1-4:x
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Station |
B.S. |
I.H. |
F.S. |
ELEV. |
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B.M. |
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Topic 3 – Site Investigation and Building Layout with Hand Tools
Site investigation is a two-stage process consisting of a surface evaluation and a subsurface investigation. The surface elevation will provide information to the builder on site conditions such as how level the area is and if materials like rock or soil need to be added or removed. The subsurface investigation is important to determine if the conditions below the surface will support the structure being built. Soil samples are taken to determine bearing strength and shear capacity of the soil. Knowing the bearing and shear capacity is important. A low bearing capacity may require deeper or larger piles or a different type of foundation altogether. Determining the level of groundwater and level of frost penetration can be determined as part of the subsurface investigation. Compaction testing will determine if the surface supports foundations, sidewalks, roadways and parking lots.
Other important factors in a site investigation are:
1) site access
2) utilities and services
3) site safety and local bylaws.
Building Layout
The dimensions and location of a building are laid out from the property corners marked by the surveyor and referenced on the plot plan. Typically, we establish the front of the building line first. From