01580y
Olson !f,al ker As`_ -,i ates Architects
April 11, 1980
page G
such as the guideline shown in Figure 9 (attached herewith) to assist
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the design and construction. Other routine procedures acceptable
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to the architect can be utilized for the proposed project. Good.
.,
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backwall drainage system is strongly recommended since seepage zones
were erPcountered at the basement levels.
7.9. OPEN CUT
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It is understood that a basement cut with.a height of 13 to 15 feet:
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will be. made for daylighted basement construction.
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Unsupported excavation slopes are considered adequate for all'
be for excavation.
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excavation. The following cut angle may used
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depths of cut _ P�
up to 15 feet+ 1V on 0.7b11;
:
30 feet 1V on lfl
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est that localized
Some sand layers noted in the test pits sugg Burin basement'
be in the slopes g
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waterbearing soils may exposed
excavation. It is possible that waterbearing zones. -may require treattiiient
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to prevent excessive loss of ground by "piping".
Where groundwater is encountered, benching the slope and blanketing
sand and gravel
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the seepage zone with a 12 inch layer of washed
to protect the slope from sloughing.
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mixture is recommended
Dry weather construction from June to September will be very desirable
for the basement and footing
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to limit the adverse groundwater effects
excavation.
All slopes will have a tend ency to slough or erode if left
Therefore, all exposed
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unprotected during periods of wet weather.
slopes should be covered during the rainy season with plastic
sheeting or some other suitable material.
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7.10 BACKFILL ?MATERIALS