The Ontario Building Code | Allowable Bearing Pressures

9.4.4.1. Allowable Bearing pressures

(1) footing sizes for shallow foundations shall be,

(a) determined in accordance with Section 9.15., or

(b) designed in accordance with Section 4.2. using,

(i) the maximum allowable bearing pressures in Table 9.4.4.1., or

(ii) allowable bearing pressures determined from subsurface investigation.

Table 9.4.4.1.
Allowable Bearing pressure for soil or Rock

Forming Part of Sentence 9.4.4.1.(1)

Item

Column 1

Type and Condition of soil or Rock

Column 2

Maximum Allowable Bearing pressure, kPa

1.

Dense or compact sand or gravel

150

2.

Loose sand or gravel

50

3.

Dense or compact silt

100

4.

Stiff clay

150

5.

Firm clay

75

6.

Soft clay

40

7.

Till

200

8.

Clay shale

300

9.

Sound rock

500

(2) The design procedures described in Section 4.2. are permitted to be used in lieu of the design procedures in this Subsection.

(3) The design procedures described in Section 4.2. shall be used where,

(a) deep foundations are used,

(b) the footing size falls outside the scope of this Section, or

(c) the foundationis constructed on peat, filled ground or on sensitive clays as described in Article 9.15.1.1.