Hong Kong Regulations

BUILDING (CONSTRUCTION) REGULATIONS - REGULATION 25

Allowable capacity for bearing, bond or friction of ground

(1) The allowable capacity for bearing, bond or friction of the ground
supporting any foundation under working load shall not exceed-

   (a)  the ultimate capacity for bearing, bond or friction of that ground
        with an adequate factor of safety against failure; or

   (b)  the value in relation to bearing, bond or friction of that ground such
        that the deformation or movement (including total settlement,
        differential settlement and lateral movement) will not be greater than
        that which can be tolerated by the building, building works, structure
        or street supported by the foundation, whichever is the less.

(2) The ultimate capacity for bearing, bond or friction of the supporting
ground shall be determined by-

   (a)  suitable tests to establish the engineering properties of the
        supporting ground together with the application of recognized
        foundation engineering principles; or

   (b)  testing of the foundation on site; or

   (c)  other suitable methods.

(3) Where the allowable bearing capacity is to be determined on the basis of
the ultimate bearing capacity of the supporting ground, due consideration
shall be given to all the circumstances, including the ground water
conditions, the shape and depth of the foundation, the inclination and
eccentricity of the loads, and the nature and slope of the surrounding ground,
and, in the case of rock, the presence of dissolution features, the jointing
of the rock and the spacing, dip, thickness and degree of weathering of the
joints and any other relevant characteristics.

(4) The allowable capacity of foundations for bearing, bond or friction
resisting the combined effects of dead, imposed and wind loads may be
increased by not more than 25% where such increase is solely due to
wind loads. (Enacted 1990)