4.1.8.16.

(1) Foundations shall be designed to resist the lateral load capacity of the SFRS, except that when the foundations are allowed to rock, the design forces for the foundation need not exceed those determined in Sentence 4.1.8.7.(1) using an R_dR_o equal to 2.0.

(2) The design of foundations shall be such that they are capable of transferring earthquake loads and effects between the building and the ground without exceeding the capacities of the soil and rock.

(3) In cases where I_EF_aS_a(0.2) is equal to or greater than 0.35, the following requirements shall be satisfied:

(a) piles or pile caps, drilled piers, and caissons shall be interconnected by continuous ties in no fewer than two directions,

(b) piles, drilled piers, and caissons shall be embedded a minimum of 100 mm into the pile cap or structure, and

(c) piles, drilled piers, and caissons, other than wood piles, shall be connected to the pile cap or structure for a minimum tension force equal to 0.15 times the factored compression load on the pile.

(4) At sites where I_EF_aS_a(0.2) is equal to or greater than 0.35, basement walls shall be designed to resist earthquake lateral pressures from backfill or natural ground.

(5) At sites where I_EF_aS_a(0.2) is greater than 0.75, the following requirements shall be satisfied:

(a) piles, drilled piers, or caissons shall be designed and detailed to accommodate cyclic inelastic behaviour when the design moment in the element due to earthquake effects is greater than 75% of its moment capacity, and

(b) spread footings founded on soil defined as Site Class E or F shall be interconnected by continuous ties in no fewer than two directions.

(6) Each segment of a tie between elements that is required by Clauses (3)(a) or (5)(b) shall be designed to carry by tension or compression a horizontal force at least equal to the greatest factored pile cap or column vertical load in the elements it connects, multiplied by a factor of 0.10 I_EF_aS_a(0.2), unless it can be demonstrated that equivalent restraints can be provided by other means.

(7) The potential for liquefaction of the soil and its consequences, such as significant ground displacement and loss of soil strength and stiffness, shall be evaluated based on the ground motion parameters referenced in Subsection 1.1.2. and shall be taken into account in the design of the structure and its foundations.