Table 2‐1 Approximate Load Bearing Capacities of Various Soil Types

Soil Type

 

 

Safe Bearing Capacity

 

lb per ft2

kilo Pascals

 

Hard Rock - Granite etc.

50,000

- 200,000

2,395

- 9,576

Medium Rock - Shale etc.

20,000

- 30,000

958 - 1,436

Hardpan

16,000

- 20,000

766

- 958

Soft Rock

10,000

- 20,000

479

- 958

Compacted Sand and Gravel

10,000

- 12,000

479

- 575

Hard Clay

8,000

- 10,000

383

- 479

Gravel and Coarse Sand

8,000

- 10,000

383

- 479

Loose, Medium and Coarse Sand

8,000

- 10,000

383

- 479

Compacted Fine Sand

6,000

- 8,000

287

- 383

Medium Clay

4,000

- 8,000

192

- 383

Loose Fine Sand

2,000

- 4,000

96 - 192

Soft Clay

2,000

 

96

Table 2‐1 shows approximate load bearing capacities for various types of soil if the actual load bearing capacity of the soil under the foundation is not known.

Caution: Check the local building codes for load bearing capacity requirements.

Caution: If the soil is subject to freezing and thawing, the foundation must be extended below the frost line. Check the local building codes.

SReinforce the foundation with No. 8 gauge steel wire mesh placed horizontally on 6in (150mm) centers. As an alternative, use No. 6 re-bars on 12in (300mm) centers horizontally. Minimum cover over the bars should be 3in (76mm).

SSuggested concrete mixture by volume is 1 part cement, 2 parts sand, and 3 parts aggregate. Maximum slump of 4in (100mm) and a 28-day compressive strength of 3000 psi (20,600 kPa).

SThe size of the bolts holding the sub-base to the foundation should be sized to fit the mounting holes shown on the Installation Diagram.

SThree-inch (76mm) iron pipe sleeves should be placed around the bolts in the foundation to allow for any mislocation of the bolts after the foundation hardens. “J” or “L” type bolts are recommended for the foundation bolts.

SAfter the foundation is cured and the genset is located, the sleeves are filled with grout. Figure 2‐5 shows a typical foundation installation.

Figure 2‐5 Typical Foundation Installation

2‐8 General Information

MN2408

Page 18
Image 18
Baldor GLC100, GLC60, GLC105 ‐5 Typical Foundation Installation, Soil Type Safe Bearing Capacity Lb per ft Kilo Pascals