jswizzle3737/ontario_laws_and_regs huggingface dataset:
Notes to Table 4.1.5.11.:
4.1.5.14. Loads on Guards and Handrails (1) The minimum specified horizontal load applied outward at the minimum required height of every required guard shall be, (a) 3.0 kN/m for open viewing stands without fixed seats and for means of egress in grandstands, stadia, bleachers and arenas, (b) a concentrated load of 1.0 kN applied at any point so as to produce the most critical effect, for access ways to equipment platforms, contiguous stairs and similar areas where the gathering of many people is improbable, and (c) 0.75 kN/m or a concentrated load of 1.0 kN applied at any point so as to produce the most critical effect, whichever governs for locations other than those described in Clauses (a) and (b). (2) The minimum specified horizontal load applied inward at the minimum required height of every required guard shall be half that specified in Sentence (1). (3) Individual elements within the guard, including solid panels and pickets, shall be designed for a load of 0.5 kN applied outward over an area of 100 mm by 100 mm located at any point in the element or elements so as to produce the most critical effect. (4) The size of the opening between any two adjacent vertical elements within a guard shall not exceed the limits required by Part 3 when each of these elements is subjected to a specified live load of 0.1 kN applied in opposite directions in the in-plane direction of the guard so as to produce the most critical effect. (5) The loads required in Sentence (3) need not be considered to act simultaneously with the loads provided for in Sentences (1), (2) and (6). (6) The minimum specified load applied vertically at the top of every required guard shall be 1.5 kN/m and need not be considered to act simultaneously with the horizontal load provided for in Sentence (1). (7) Handrails and their supports shall be designed and constructed to withstand the following loads, which need not be considered to act simultaneously: (a) a concentrated load not less than 0.9 kN applied at any point and in any direction for all handrails, and (b) a uniform load not less than 0.7 kN/m applied in any direction to handrails not located within dwelling units.
Notes to Table 4.1.5.11.:
4.1.5.15. Loads on Vehicle Guardrails (1) Vehicle guardrails shall be designed for a concentrated load of 22 kN applied horizontally outward at any point 500 mm above the floor surface so as to produce the most critical effect. (2) The loads described in Sentence (1) need not be considered to act simultaneously with the loads provided for in Article 4.1.5.14.
Notes to Table 4.1.5.11.:
4.1.5.16. Loads on Walls Acting As Guards (1) Where the floor elevation on one side of a wall, including a wall around a shaft, is more than 600 mm higher than the elevation of the floor or ground on the other side, the wall shall be designed to resist the appropriate outward lateral design loads prescribed elsewhere in this Subsection or 0.5 kPa acting outward, whichever produces the more critical effect.
Notes to Table 4.1.5.11.:
4.1.5.17. Firewalls (1) Firewalls shall be designed to resist the maximum effect due to, (a) the appropriate lateral design loads prescribed elsewhere in this Section, or (b) a factored lateral load of 0.5 kPa under fire conditions, as described in Sentence (2). (2) Under fire conditions, where the fire-resistance rating of the structure is less than that of the firewall, (a) lateral support shall be assumed to be provided by the structure on one side only, or (b) another structural support system capable of resisting the loads imposed by a fire on either side of the firewall shall be provided. 4.1.6. Loads Due to Snow and Rain
Notes to Table 4.1.5.11.:
4.1.6.1. Specified Load Due to Rain or to Snow and Associated Rain (1) The specified load on a roof or any other building surface subject to snow and associated rain shall be the snow load specified in Article 4.1.6.2., or the rain load specified in Article 4.1.6.4., whichever produces the more critical effect.
Notes to Table 4.1.5.11.:
4.1.6.3. Full and Partial Loading (1) A roof or other building surface and its structural members subject to loads due to snow accumulation shall be designed for the specified load in Sentence 4.1.6.2.(1), distributed over the entire loaded area. (2) In addition to the distribution in Sentence (1), flat roofs and shed roofs, gable roofs of 15° slope or less, and arched or curved roofs shall be designed for the specified uniform snow load indicated in Sentence 4.1.6.2.(1), which shall be calculated using Ca = 1.0, distributed on any one portion of the loaded area, and half of this load on the remainder of the loaded area, in such a way as to produce the most critical effects on the member concerned.
Notes to Table 4.1.5.11.:
4.1.6.4. Specified Rain Load (1) Except as provided in Sentence (4), the specified load, S, due to the accumulation of rainwater on a surface whose position, shape and deflection under load make such an accumulation possible, is that resulting from the one-day rainfall determined in conformance with Subsection 1.1.2. and applied over the horizontal projection of the surface and all tributary surfaces. (2) The provisions of Sentence (1) apply whether or not the surface is provided with a means of drainage, such as rainwater leaders. (3) Except as provided for in Sentence 4.1.6.2.(1), loads due to rain need not be considered to act simultaneously with loads due to snow. (4) Where scuppers are provided and where the position, shape and deflection of the loaded surface make an accumulation of rainwater possible, the loads due to rain shall be the lesser of either the one-day rainfall determined in conformance with Subsection 1.1.2. or a depth of rainwater equal to 30 mm above the level of the scuppers, applied over the horizontal projection of the surface and tributary areas.
Notes to Table 4.1.5.11.:
4.1.6.5. Multi-Level Roofs (1) The drifting load of snow on a roof adjacent to a higher roof shall be taken as trapezoidal, as shown in Figure 4.1.6.5.A., where the accumulation factor, Ca, is, Ca = Ca0 – (Ca0
– 1)(x/xd), for 0 ≤ x ≤ xd or Ca = 1.0, for x > xd where, Ca0 = peak value of Ca at x = 0 as specified in Sentences (3) and (4) and as shown in Figure 4.1.6.5.A., x = distance from roof step as shown in Figure 4.1.6.5.A., and xd = length of drift as specified in Sentence (2) and as shown in Figure 4.1.6.5.A. (2) The length of the drift, xd, shall be calculated as follows:  where, γ = specific weight of snow as specified in Article 4.1.6.13. (3) The value of Ca0
for each of Cases I, II and III shall be the lesser of,  where, β = 1.0 for Case I and 0.67 for Cases II and III, h = difference in elevation between the lower roof surface and the top of the parapet on the upper roof as shown in Figure 4.1.6.5.A., and  where, Cws =  value for Cw
applicable to the source of drifting, lcs = the characteristic length of the source area for drifting, defined as , where ws and ls are respectively the shorter and longer dimensions of the relevant source areas for snow drifting shown in Figure 4.1.6.5.B. for Cases I, II and III, and  where, hp = height of the roof perimeter parapet of the source area, to be taken as zero unless all the roof edges of the source area have parapets. (4) The value of Ca0
shall be the highest of Cases I, II and III, considering the different roof source areas for drifting snow, as specified in Sentence (3) and Figure 4.1.6.5.B. Figure 4.1.6.5.A.   Snow Load Factors for Lower Level Roofs Forming Part of Sentences 4.1.6.5.(1) and (3) and 4.1.6.6.(1)
Notes to Figure 4.1.6.5.A.:
4.1.6.6. Horizontal Gap between a Roof and a Higher Roof (1) Where the roof of one building is separated by a distance, a, from an adjacent building
with a higher roof as shown in Figure 4.1.6.5.A., the influence of the adjacent
building on the value of the accumulation factor, Ca, for the lower roof shall be determined as follows: (a) if a > 5 m, the influence of the adjacent building on Ca need not be considered, and (b) if a ≤ 5 m, Ca
for the lower roof shall be calculated in accordance with Article 4.1.6.5. for values of x ≥ a.
Notes to Figure 4.1.6.5.A.:
4.1.6.7. Areas Adjacent to Roof Projections (1) Except as provided in Sentences (2) and (3), the accumulation factor, Ca, for areas adjacent to roof-mounted vertical projections shall be calculated in accordance with Sentence 4.1.6.5.(1) using the following values for the peak accumulation factor, Ca0, and the drift length, xd: (a) Ca0 shall be taken as the lesser of,  (b) xd shall be taken as the lesser of, (i) 3.35h, and (ii) (2/3)l0, where, h = height of the projection, and l0 = longest horizontal dimension of the projection. (2) Ca
is permitted to be calculated in accordance with Article 4.1.6.5. for larger projections. (3) Where the longest horizontal dimension of the roof projection, l0, is less than 3 m, the drift surcharge adjacent to the projection need not be considered.
Notes to Figure 4.1.6.5.A.:
4.1.6.8. Snow Drift at Corners (1) The drift loads on the lower level roof against the two faces of an outside corner of an upper level roof or roof obstruction shall be extended radially around the corner as shown in Figure 4.1.6.8.A. and may be taken as the least severe of the drift loads lying against the two faces of the corner. (2) The drift loads on the lower level roof against the two faces of an inside corner of an upper level roof or a parapet shall be calculated for each face and applied as far as the bisector of the corner angle as shown in Figure 4.1.6.8.B. Figure 4.1.6.8.A.   Snow Load at Outside Corner Forming Part of Sentence 4.1.6.8.(1)  Figure 4.1.6.8.B.   Snow Load at Inside Corner Forming Part of Sentence 4.1.6.8.(2)
Notes to Figure 4.1.6.5.A.:
4.1.6.9. Gable Roofs (1) For all gable roofs, the full and partial load cases defined in Article 4.1.6.3. shall be considered. (2) For gable roofs with a slope of a > 15°, the unbalanced load case shall also be considered by setting the values of the accumulation factor, Ca, as follows: (a) on the upwind side of the roof peak, Ca shall be taken as 0, and (b) on the downwind side of the roof peak, Ca shall be taken as, (i) 0.25 + a/20, where 15° ≤ a ≤ 20°, and (ii) 1.25, where 20° < a
≤ 90°. (3) For all gable roofs, the slope factor, Cs, shall be as prescribed in Sentences 4.1.6.2.(5) and (6). (4) For all gable roofs, the wind exposure factor, Cw, shall be, (a) as prescribed in Sentences 4.1.6.2.(3) and (4) for the full and partial load cases, and (b) 1.0 for the unbalanced load case referred to in Sentence (2).
Notes to Figure 4.1.6.5.A.:
4.1.6.10. Arch Roofs, Curved Roofs and Domes (1) For all arch roofs, curved roofs and domes, the full and partial load cases defined in Article 4.1.6.3. shall be considered. (2) For arch roofs, curved roofs and domes with rise-to-span ratio h/b > 0.05 as shown in Figure 4.1.6.10.A., the load cases provided in Sentences (3) to (7) shall also be considered. (3) For arch roofs with a slope at the edge αe ≤ 30° as shown in Figure 4.1.6.10.A. and as described in Table 4.1.6.10., Ca shall be, (a) taken as 0 on the upwind side of the peak, and (b) on the downwind side of the peak, taken as,  where, x = horizontal distance from the roof peak, h = height of arch, and b = width of arch. Figure 4.1.6.10.A.   Accumulation Factors for Arch Roofs and Curved Roofs(1) Forming Part of Sentences 4.1.6.10.(2) to (4)
Notes to Figure 4.1.6.10.B.:
4.1.6.11. Snow Loads Due to Sliding (1) Except as provided in Sentence (2), where an upper roof, or part thereof, slopes downwards with a slope α > 0 towards a lower roof, the snow load, S, on the lower roof, determined in accordance with Articles 4.1.6.2. and 4.1.6.5., shall be augmented in accordance with Sentence (3) to account for the additional load resulting from sliding snow. (2) Sentence (1) need not apply where, (a) snow from the upper roof is prevented from sliding by a parapet or other effective means, or (b) the upper roof is not considered slippery and has a slope less than 20°. (3) The total weight of additional snow resulting from sliding shall be taken as half the total weight of snow resulting from the uniform load case prescribed in Article 4.1.6.2. with, (a) the accumulation factor Ca
= 1.0 for the relevant part of the upper roof, (b) the slope factor, Cs, based on the slope of the lower roof, as prescribed in Sentences 4.1.6.2.(5) and (6), and (c) the sliding snow distributed on the lower roof such that it is a maximum for x = 0 and decreases linearly to 0 at x = xd, as shown in Figure 4.1.6.11., where x and xd
are as defined in Article 4.1.6.5. Figure 4.1.6.11.   Snow Distribution on Lower Roof with Sloped Upper Roof Forming Part of Sentence 4.1.6.11.(3)
Notes to Figure 4.1.6.10.B.:
4.1.6.12. Valleys in Curved or Sloped Roofs (1) For valleys in curved or sloped roofs with a slope α >10°, in addition to the full and partial load cases defined in Article 4.1.6.3., the non-uniform load Cases II and III described in Sentences (2) and (3) shall be considered to account for sliding, creeping and movement of meltwater. (2) For Case II as shown in Figure 4.1.6.12., the accumulation factor, Ca, shall be calculated as follows:  where, x = horizontal distance from the bottom of the valley, and b = twice the horizontal distance between the bottom of the valley and the peak of the roof surface under consideration. (3) For Case III as shown in Figure 4.1.6.12., Ca shall be calculated as follows:  where, x, b =  as specified in Sentence (2). Figure 4.1.6.12.   Snow Loads in Valleys of Sloped or Curved Roofs(1),(2) Forming Part of Sentences 4.1.6.12.(2) and (3)
Notes to Figure 4.1.6.12.:
4.1.6.13. Specific Weight of Snow (1) For the purposes of calculating snow loads in drifts, the specific weight of snow, γ, shall be taken as the lesser of 4.0 kN/m3
and 0.43SS + 2.2 kN/m3.
Notes to Figure 4.1.6.12.:
4.1.6.14. Snow Removal (1) Snow removal by mechanical, thermal, manual or other means shall not be used as a rationale to reduce design snow loads.
Notes to Figure 4.1.6.12.:
4.1.6.15. Ice Loading of Structures (1) For lattice structures connected to the building, and other building components or appurtenances involving small width elements subject to significant ice accretion, the weight of ice accretion and the effective area presented to wind shall be as prescribed in CSA S37, “Antennas, Towers, and Antenna-Supporting Structures”.
Notes to Figure 4.1.6.12.:
4.1.7. Wind Load
Notes to Figure 4.1.6.12.:
4.1.7.1. Specified Wind Load (1) The specified wind loads for a building
and its components shall be determined using the Static, Dynamic or Wind Tunnel Procedure as provided in Sentences (2) to (5). (2) For the design of buildings that are not classified as dynamically sensitive in accordance with Sentence 4.1.7.2.(1), one of the following procedures shall be used to determine the specified wind loads: (a) the Static Procedure described in Article 4.1.7.3., (b) the Dynamic Procedure described in Article 4.1.7.8., or (c) the Wind Tunnel Procedure described in Article 4.1.7.12. (3) For the design of buildings that are classified as dynamically sensitive in accordance with Sentence 4.1.7.2.(2), one of the following procedures shall be used to determine the specified wind loads: (a) the Dynamic Procedure described in Article 4.1.7.8., or (b) the Wind Tunnel Procedure described in Article 4.1.7.12. (4) For the design of buildings that may be subject to wake buffeting or channelling effects from nearby buildings, or that are classified as very dynamically sensitive in accordance with Sentence 4.1.7.2.(3), the Wind Tunnel Procedure described in Article 4.1.7.12. shall be used to determine the specified wind loads. (5) For the design of cladding and secondary structural members, one of the following procedures shall be used to determine the specified wind loads: (a) the Static Procedure described in Article 4.1.7.3., or (b) the Wind Tunnel Procedure described in Article 4.1.7.12. (6) Computational fluid dynamics shall not be used to determine the specified wind loads for a building and its components.
Notes to Figure 4.1.6.12.:
4.1.7.2. Classification of Buildings (1) Except as provided in Sentences (2) and (3), a building is permitted to be classified as not dynamically sensitive. (2) A building shall be classified as dynamically sensitive if, (a) its lowest natural frequency is less than 1 Hz and greater than 0.25 Hz, (b) its height is greater than 60 m, or (c) its height is greater than 4 times its minimum effective width considering all wind directions, where the effective width, w, of a building shall be taken as,  where, the summations are over the height of the building for a given wind direction, hi = the height above grade to level i, and wi = the width normal to the wind direction at height hi. (3) A building shall be classified as very dynamically sensitive if, (a) its lowest natural frequency is less than or equal to 0.25 Hz, or (b) its height is more than 6 times its minimum effective width, where the minimum effective width is determined in accordance with Clause (2)(c).
Notes to Figure 4.1.6.12.:
4.1.7.4. Topographic Factor (1) Except as provided in Sentence (2), the topographic factor, Ct, shall be taken as 1.0. (2) For buildings on hills or escarpments with slope, Hh/(2Lh), greater than 0.1 as shown in Figure 4.1.7.4., the topographic factor, Ct, shall be calculated as follows:  where,  where, ΔSmax =  applicable values from Table 4.1.7.4., x = horizontal distance from the peak of the hill or escarpment, Lh = horizontal distance upwind from the peak to the point where the ground surface lies at half the height of the hill or escarpment, or 2Hh where Hh is the height of the hill or escarpment, whichever is greater, z = height above ground, and k and α = applicable constants from Table 4.1.7.4. based on shape of hill or escarpment. Figure 4.1.7.4.   Speed-up of Mean Velocity on a Hill or Escarpment(1) Forming Part of Sentence 4.1.7.4.(2)
Notes to Table 4.1.7.4.:
4.1.7.5. External Pressure Coefficients (1) Applicable values of external pressure coefficients, Cp, are provided in, (a) Sentences (2) to (5), and (b) Article 4.1.7.6. for certain shapes of low buildings. (2) For the design of the main structural system, the value of Cp shall be established as follows, where H is the height of the building
and D is the width of the building parallel to the wind direction: (a) on the windward face, Cp = 0.6 for H/D < 0.25 = 0.27(H/D + 2) for 0.25 ≤ H/D < 1.0 = 0.8 for H/D ≥ 1.0, (b) on the leeward face, Cp = –0.3 for H/D < 0.25 = –0.27(H/D + 0.88) for 0.25 ≤ H/D < 1.0 = –0.5 for H/D ≥ 1.0, and (c) on the walls parallel to the wind, Cp = –0.7. (3) For the design of roofs, the value of Cp shall be established as follows, where x is the distance from the upwind edge of the roof: (a) for H/D ≥ 1.0, Cp
= –1.0, and (b) for H/D <1.0, Cp = –1.0 for x ≤ H = –0.5 for x > H (4) For the design of the cladding and of secondary structural elements supporting the cladding, the value of Cp shall be established as follows, where W and D are the widths of the building: (a) on walls, Cp shall be taken as ±0.9, except that within a distance equal to the larger of 0.1D and 0.1W from a building corner the negative value of Cp shall be taken as –1.2, (b) on walls where vertical ribs deeper than 1 m are placed on the facade, Cp shall be taken as ±0.9, except that within a distance equal to the larger of 0.2D and 0.2W from a building corner the negative value of Cp shall be taken as –1.4, and (c) on roofs, Cp shall be taken as –1.0, except that, (i) within a distance equal to the larger of 0.1D and 0.1W from a roof edge, Cp shall be taken as –1.5, (ii) in a zone that is within a distance equal to the larger of 0.2D and 0.2W from a roof corner, Cp
shall be taken as –2.3 but is permitted to be taken as –2.0 for roofs with perimeter parapets that are higher than 1 m, and (iii) on lower levels of flat stepped roofs, positive pressure coefficients established for the walls of the steps apply for a distance b as shown in Figure 4.1.7.6.D. (5) For the design of balcony guards, the internal pressure coefficient, Cpi, shall be taken as zero and the value of Cp
shall be taken as ±0.9, except that within a distance equal to the larger of 0.1D and 0.1W from a building corner, Cp shall be taken as ±1.2.
Notes to Table 4.1.7.4.:
4.1.7.6. External Pressure Coefficients for Low Buildings (1) For the design of buildings with a height, H, that is less than or equal to 20 m and less than the smaller plan dimension, the values of the product of the pressure coefficient and gust factor, CpCg, provided in Sentences (2) to (9) are permitted to be used. (2) For the design of the main structural system of the building, which is affected by wind pressures on more than one surface, the values of CpCg
are provided in Figure 4.1.7.6.A. (3) For the design of individual walls and wall cladding, the values of CpCg
are provided in Figure 4.1.7.6.B. (4) For the design of roofs with a slope less than or equal to 7o, the values of CpCg
are provided in Figure 4.1.7.6.C. (5) For the design of flat roofs with steps in elevation, the values of CpCg
are provided in Figure 4.1.7.6.D. (6) For the design of gabled or hipped, single-ridge roofs with slope greater than 7o, the values of CpCg are provided in Figure 4.1.7.6.E. (7) For the design of gabled, multi-ridge roofs, the values of CpCg are provided in, (a) Figure 4.1.7.6.C. for roofs with slope less than or equal to 10o, and (b) Figure 4.1.7.6.F. for roofs with slope greater than 10o. (8) For monosloped roofs, the values of CpCg are provided in, (a) Figure 4.1.7.6.C. for roofs with a slope less than or equal to 3o, and (b) Figure 4.1.7.6.G. for roofs with a slope greater than 3o and less than or equal to 30o. (9) For sawtooth roofs, the values of CpCg are provided in, (a) Figure 4.1.7.6.C. for roofs with a slope less than or equal to 10o, and (b) Figure 4.1.7.6.H. for roofs with a slope greater than 10o. Figure 4.1.7.6.A.    External Peak Values of CpCg for Primary Structural Actions Arising from Wind Load Acting Simultaneously on All Surfaces of Low Buildings, H ≤20 m(1),(2),(3),(4) Forming Part of Sentence 4.1.7.6.(2)
Notes to Figure 4.1.7.6.H.:
4.1.7.7. Internal Pressure Coefficient (1) The internal pressure coefficient, Cpi, shall be as prescribed in Table 4.1.7.7. Table 4.1.7.7.   Internal Pressure Coefficients Forming Part of Sentence 4.1.7.7.(1) Item   Column 1 Building openings   Column 2 Values for Cpi 

  1.   Uniformly distributed small openings amounting to less than 0.1% of the total surface area    –0.15 to 0.0  

  2.   Non-uniformly distributed openings of which none is significant or significant openings that are wind-resistant and closed during storms    –0.45 to +0.30  

  3.   Large openings likely to remain open during storms    –0.70 to +0.70
Notes to Figure 4.1.7.6.H.:
4.1.7.8. Dynamic Procedure (1) For the application of the Dynamic Procedure, the provisions of Article 4.1.7.3. shall be followed, except that the exposure factor, Ce, shall be as prescribed in Sentences (2) and (3), and the gust effect factor, Cg, shall be as prescribed in Sentence (4), when determining the wind loads on the main structural system. (2) For buildings in open terrain as described in Clause 4.1.7.3.(5)(a), the value of Ce for the design of the main structural system shall be calculated as follows: Ce = (h/10)0.28, but 1.0 ≤ Ce ≤ 2.5 (3) For buildings in rough terrain as described in Clause 4.1.7.3.(5)(b), the value of Ce for the design of the main structural system shall be calculated as follows: Ce = 0.5(h/12.7)0.5, but 0.5 ≤ Ce ≤ 2.5 (4) For the design of the main structural system, Cg shall be calculated as follows: Cg = 1 + gp(δ/μ) where, gp = peak factor calculated as, and , where, υ = average fluctuation rate calculated as , T = 3 600 s, K = 0.08 for open terrain and 0.10 for rough terrain, CeH =  exposure factor evaluated at reference height h = H, B = background turbulence factor, a function of w/H determined from Figure 4.1.7.8., s = size reduction factor calculated as , F = gust energy ratio calculated as , where x0 = (1 220 fn/VH), and β = damping ratio, which shall be determined by a rational method or may be taken to be 0.01 for steel structures, 0.02 for concrete structures and 0.015 for composite structures, where, fnD = natural frequency of vibration of the building in the along-wind direction, in Hz, fn = lowest natural frequency of the building, in Hz, as described in Sentences 4.1.7.2.(2) and (3), H = height of the building, w = effective width of windward face of the building calculated as , where wi
= width normal to wind direction at height hi, and VH = mean wind speed at the top of the structure, in m/s, calculated as , where, = reference wind speed at a height of 10 m, in m/s, calculated as , where, Iw = importance factor, q = reference velocity pressure, in Pa, and ϱ = air density = 1.2929 kg/m3. Figure 4.1.7.8.   Background Turbulence Factor, B Forming Part of Sentence 4.1.7.8.(4)
Notes to Figure 4.1.7.6.H.:
4.1.7.9. Full and Partial Wind Loading (1) Except where the wind loads are derived from the combined CpCg values determined in accordance with Article 4.1.7.6., buildings
and structural members shall be capable of withstanding the effects of, (a) the full wind loads acting along each of the two principal horizontal axes considered separately, (b) the wind loads as described in Clause (a) but with 100% of the load removed from any one portion of the area, (c) the wind loads as described in Clause (a) but with both axes considered simultaneously at 75% of their full value, and (d) the wind loads as described in Clause (c) but with 50% of these loads removed from any portion of the area.
Notes to Figure 4.1.7.6.H.:
4.1.7.10. Interior Walls and Partitions (1) In the design of interior walls and partitions, due consideration shall be given to differences in air pressure on opposite sides of the wall or partition that may result from, (a) pressure differences between the windward and leeward sides of a building, (b) stack effects due to a difference in air temperature between the exterior and interior of the building, and (c) air pressurization by the mechanical services of the building.
Notes to Figure 4.1.7.6.H.:
4.1.7.11. Exterior Ornamentations, Equipment and Appendages (1) The effects of wind loads on exterior ornamentations, equipment and appendages, including the increase in exposed area as a result of ice buildup as described in CSA S37, “Antennas, Towers, and Antenna-Supporting Structures”, shall be considered in the structural design of the connections and the building. (2) Where there are a number of similar components, the net increase in force is permitted to be based on the total area for all similar components as opposed to the summation of forces of individual elements.
Notes to Figure 4.1.7.6.H.:
4.1.7.12. Wind Tunnel Procedure (1) Except as provided in Sentences (2) and (3), wind tunnel tests on scale models to determine wind loads on buildings shall be conducted in accordance with ASCE/SEI 49, “Wind Tunnel Testing for Buildings and Other Structures”. (2) Where an adjacent building provides substantial sheltering effect, the wind loads for the main structural system shall be no lower than 80% of the loads determined from tests described  in Sentence (1) with the effect of the sheltering building removed as applied to, (a) the base shear force for buildings with ratio of height to minimum effective width, as described in Sentence 4.1.7.2.(2), less than or equal to 1.0, or (b) the base moment for buildings with a ratio of height to minimum effective width greater than 1.0. (3) For the design of cladding and secondary structural members, the exterior wind loads determined from the wind tunnel tests shall be no less onerous than those determined by analysis in accordance with Article 4.1.7.3. using the following assumptions: (a) Cp = ±0.72 and Cg
= 2.5, where the height of the building is greater than 20 m or greater than its minimum effective width, and (b) CpCg = 80% of the values for zones w and r provided in Article 4.1.7.6., where the height of the building is less than or equal to 20 m and no greater than its minimum effective width.
Notes to Figure 4.1.7.6.H.:
4.1.8. Earthquake Load and Effects
Notes to Figure 4.1.7.6.H.:
4.1.8.3. General Requirements (1) The building shall be designed to meet the requirements of this Subsection and of the design standards referenced in Section 4.3. (2) Structures shall be designed with a clearly defined load path, or paths, that will transfer the inertial forces generated in an earthquake to the supporting ground. (3) The structure shall have a clearly defined Seismic Force Resisting System(s) (SFRS), as defined in Article 4.1.8.2. (4) The SFRS shall be designed to resist 100% of the earthquake loads and their effects. (5) All structural framing elements not considered to be part of the SFRS must be investigated and shown to behave elastically or to have sufficient non-linear capacity to support their gravity loads while undergoing earthquake-induced deformations calculated from the deflections determined in Article 4.1.8.13. (6) Stiff elements that are not considered part of the SFRS, such as concrete, masonry, brick or pre-cast walls or panels, shall be, (a) separated from all structural elements of the building such that no interaction takes place as the building undergoes deflections due to earthquake effects as calculated in this Subsection, or (b) made part of the SFRS and satisfy the requirements of this Subsection. (7) Stiffness imparted to the structure from elements not part of the SFRS, other than those described in Sentence (6), shall not be used to resist earthquake deflections but shall be accounted for, (a) in calculating the period of the structure for determining forces if the added stiffness decreases the fundamental lateral period by more than 15%, (b) in determining the irregularity of the structure, except the additional stiffness shall not be used to make an irregular SFRS regular or to reduce the effects of torsion, and (c) in designing the SFRS if inclusion of the elements not part of the SFRS in the analysis has an adverse effect on the SFRS. (8) Structural modelling shall be representative of the magnitude and spatial distribution of the mass of the building and of the stiffness of all elements of the SFRS, including stiff elements that are not separated in accordance with Sentence 4.1.8.3.(6), and shall account for, (a) the effect of cracked sections in reinforced concrete and reinforced masonry elements, (b) the effect of the finite size of members and joints, (c) sway effects arising from the interaction of gravity loads with the displaced configuration of the structure, and (d) other effects that influence the lateral stiffness of the building.
Notes to Figure 4.1.7.6.H.:
4.1.8.4. Site Properties (1) The peak ground acceleration (PGA), peak ground velocity (PGV) and the 5% damped spectral response acceleration values, Sa(T), for the reference ground conditions (Site Class C in Table 4.1.8.4.A.) for periods T of 0.2 s, 0.5 s, 1.0 s, 2.0 s, 5.0 s and 10.0 s, shall be determined in accordance with Subsection 1.1.2. and are based on a 2% probability of exceedance in 50 years. (2) Site classifications for ground shall conform to Table 4.1.8.4.A. and shall be determined using  or, where  is not known, using Sentence (3). (3) If average shear wave velocity, , is not known, Site Class shall be determined from energy-corrected Average Standard Penetration Resistance, , or from soil average undrained shear strength, su, as noted in Table 4.1.8.4.A.,  and su
being calculated based on rational analysis. (4) For the purpose of determining the values of F(T) to be used in the calculation of design spectral acceleration, S(T), in Sentence (9), and the values of F(PGA) and F(PGV), the value of PGAref to be used with Tables 4.1.8.4.B. to 4.1.8.4.I. shall be taken as, (a) 0.8 PGA, where the ratio Sa(0.2)/PGA < 2.0, and (b) 1 PGA, in all other cases. (5) The values of the site coefficient for design spectral acceleration at period T, F(T), and of similar coefficients F(PGA) and F(PGV) shall conform to Tables 4.1.8.4.B. to 4.1.8.4.I. using linear interpolation for intermediate values of PGAref. (6) Site-specific evaluation is required to determine F(T), F(PGA) and F(PGV) for Site Class F. (7) For all applications in Subsection 4.1.8., Fa = F(0.2) and Fv = F(1.0). (8) For structures with a fundamental period of vibration equal to or less than 0.5 s that are built on liquefiable soils, Site Class and the corresponding values of F(T) may be determined as described in Tables 4.1.8.4.A., 4.1.8.4.B., and 4.1.8.4.C. by assuming that the
soils are not liquefiable. (9) The design spectral acceleration values of S(T) shall be determined as follows, using linear interpolation for intermediate values of T: S(T) = F(0.2)Sa(0.2) or F(0.5)Sa(0.5), whichever is larger, for T ≤ 0.2 s = F(0.5)Sa(0.5) for T = 0.5 s = F(1.0)Sa(1.0) for T = 1.0 s = F(2.0)Sa(2.0) for T = 2.0 s = F(5.0)Sa(5.0) for T = 5.0 s = F(10.0)Sa(10.0) for T ≥ 10.0 s Table 4.1.8.4.A.   Site Classification for Seismic Site Response Forming Part of Sentences 4.1.8.4.(1) to (3) Item   Column 1 Site Class   Column 2 Ground Profile Name   Column 3 Average Properties in Top 30 m Average Shear Wave Velocity,  (m/s)   Column 4 Average Properties in Top 30 m Average Standard Penetration Resistance,    Column 5 Average Properties in Top 30 m Soil Undrained Shear Strength, su 

  1.   A   Hard rock(1) (2)    > 1500   N/A   N/A 

  2.   B   Rock(1)   760 <  ≤ 1500   N/A   N/A 

  3.   C   Very dense soil and soft rock   360 <  < 760    > 50   su > 100kPa 

  4.   D   Stiff soil   180 <  < 360   15 ≤  ≤ 50   50 kPa < su ≤100 kPa 

  5.   E   Soft soil(3)    < 180    < 15   su < 50 kPa 

  6.    F   Other soils(4)   Site-specific evaluation required   Site-specific evaluation required   Site-specific evaluation required
Notes to Table 4.1.8.4.I.:
4.1.8.5. Importance Factor (1) The earthquake importance factor, IE, shall be determined according to Table 4.1.8.5. Table 4.1.8.5.   Importance Factor for Earthquake Loads and Effects, IE Forming Part of Sentence 4.1.8.5.(1) Item   Column 1 Importance Category   Column 2 Importance Factor, IE ULS   Column 3 Importance Factor, IE SLS 

  1.   Low   0.8   (1) 

  2.   Normal   1.0   (1) 

  3.   High   1.3   (1) 

  4.   Post-disaster   1.5   (1)
Notes to Table 4.1.8.5.:
4.1.8.6. Structural Configuration (1) Structures having any of the features listed in Table 4.1.8.6. shall be designated irregular. (2) Structures not classified as irregular according to Sentence 4.1.8.6.(1) may be considered regular. (3) Except as required by Article 4.1.8.10., in cases where IEFaSa(0.2) is equal to or greater than 0.35, structures designated as irregular must satisfy the provisions referenced in Table 4.1.8.6. Table 4.1.8.6.   Structural Irregularities(1) Forming Part of Sentence 4.1.8.6.(1) Item   Column 1 Type   Column 2 Irregularity Type and Definition   Column 3 Notes 

  1.   1   Vertical Stiffness Irregularity     

          Vertical stiffness irregularity shall be considered to exist when the lateral stiffness of the SFRS in a storey is less than 70% of the stiffness of any adjacent storey, or less than 80% of the average stiffness of the three storeys above or below.   (2)(3) 

  2.   2   Weight (mass) Irregularity    (2) 

          Weight irregularity shall be considered to exist where the weight, Wi, of any storey is more than 150% of the weight of an adjacent storey. A roof that is lighter than the floor below need not be considered.     

  3.   3   Vertical Geometric Irregularity    (2)(3)(4) 

          Vertical geometric irregularity shall be considered to exist where the horizontal dimension of the SFRS in any storey is more than 130% of that in an adjacent storey.     

  4.   4   In-Plane Discontinuity in Vertical Lateral-Force-Resisting Element     

          Except for braced frames and moment-resisting frames, an in-plane discontinuity shall be considered to exist where there is an offset of a lateral-force-resisting element of the SFRS or a reduction in lateral stiffness of the resisting element in the storey below.   (2)(3)(4) 

  5.   5   Out-of-Plane Offsets     

          Discontinuities in a lateral force path, such as out-of-plane offsets of the vertical elements of the SFRS.   (2)(3)(4) 

  6.   6   Discontinuity in Capacity – Weak Storey     

          A weak storey is one in which the storey shear strength is less than that in the storey above. The storey shear strength is the total strength of all seismic-resisting elements of the SFRS sharing the storey  shear for the direction under consideration.   (2)(3) 

  7.   7   Torsional Sensitivity (to be considered when diaphragms are not flexible)     

          Torsional sensitivity shall be considered to exist when the ratio B calculated according to Sentence 4.1.8.11.(9) exceeds 1.7.   (2)(3)(5) 

  8.   8   Non-Orthogonal Systems     

          A non-orthogonal system irregularity shall be considered to exist when the SFRS is not oriented along a set of orthogonal axes.   (6) 

  9.   9   Gravity-Induced Lateral Demand Irregularity Gravity-induced lateral demand irregularity on the SFRS shall be considered to exist where the ratio α calculated in accordance with Sentence 4.1.8.10.(5) exceeds 0.1 for SFRS with self-centering characteristics and 0.03 for other systems.    (2)(3)(6)
Notes to Table 4.1.8.6.:
4.1.8.7. Methods of Analysis (1) Analysis for design earthquake actions shall be carried out in accordance with the Dynamic Analysis Procedure described in Article 4.1.8.12., except that the Equivalent Static Force Procedure described in Article 4.1.8.11. may be used for structures that meet any of the following criteria: (a) in cases where IEFaSa(0.2) is less than 0.35, (b) regular structures that are less than 60 m in height and have a fundamental lateral period, Ta, less than 2 s in each of two orthogonal directions as defined in Article 4.1.8.8., or (c) structures with structural irregularity, of Type 1, 2, 3, 4, 5, 6 or 8 as defined in Table 4.1.8.6., that are less than 20 m in height and have a fundamental lateral period, Ta, less than 0.5 s in each of two orthogonal directions as defined in Article 4.1.8.8.
Notes to Table 4.1.8.6.:
4.1.8.8. Direction of Loading (1) Earthquake forces shall be assumed to act in any horizontal direction, except that the following shall be considered to provide adequate design force levels in the structure: (a) where components of the SFRS are oriented along a set of orthogonal axes, independent analyses about each of the principal axes of the structure shall be performed, (b) where the components of the SFRS are not oriented along a set of orthogonal axes and IEFaSa(0.2) is less than 0.35, independent analyses about any two orthogonal axes is permitted, or (c) where the components of the SFRS are not oriented along a set of orthogonal axes and IEFaSa(0.2) is equal to or greater than 0.35, analysis of the structure independently in any two orthogonal directions for 100% of the prescribed earthquake loads applied in one direction plus 30% of the prescribed earthquake loads in the perpendicular direction, with the combination requiring the greater element strength being used in the design.
Notes to Table 4.1.8.9.:
4.1.8.10. Additional System Restrictions (1) Except as required by Clause (2)(b), structures with a Type 6 irregularity, Discontinuity in Capacity – Weak Storey, as described in Table 4.1.8.6., are not permitted unless IEFaSa(0.2) is less than 0.2 and the forces used for design of the SFRS are multiplied by RdRo. (2) Post-disaster buildings shall, (a) not have any irregularities conforming to Types 1, 3, 4, 5, 7 and 9 as described in Table 4.1.8.6., in cases where IEFaSa(0.2) is equal to or greater than 0.35, (b) not have a Type 6 irregularity as described in Table 4.1.8.6., (c) have an SFRS with an Rd
of 2.0 or greater, and (d) have no storey
with a lateral stiffness that is less than that of the storey
above it. (3) For buildings having fundamental lateral periods, Ta, of 1.0 s or greater and where IEFvSa(1.0) is greater than 0.25, shear walls that are other than wood-based and form part of the SFRS shall be continuous from their top to the foundation
and shall not have irregularities of Type 4 or 5 as described in Table 4.1.8.6. (4) For buildings constructed with more than 4 storeys of continuous wood construction and where IEFaSa(0.2) is equal to or greater than 0.35, timber SFRS of shear walls with wood-based panels, braced frames or moment-resisting frames as defined in Table 4.1.8.9. within the continuous wood construction shall not have irregularities of Type 4 or 5 as described in Table 4.1.8.6. (4.1) For buildings where IEFaSa(0.2) is equal to or greater than 0.35 or IEFvSa(1.0) is equal to or greater than 0.2 that are constructed with more than 4 storeys of continuous wood construction, timber SFRSs consisting of moderately ductile or limited ductility cross-laminated timber shear walls, platform-type construction, as defined in Table
4.1.8.9., within the continuous wood construction shall not have Type 4, 5, 6, 8, or 9 irregularities as described in Table 4.1.8.6. (5) The ratio, α, for Type 9 irregularity as described in Table 4.1.8.6. shall be determined independently for each orthogonal direction using the following equation: 𝛼 = QG / Qy where, QG = gravity-induced lateral demand on the SFRS at the critical level of the yielding system, and Qy = the resistance of the yielding mechanism required to resist the minimum earthquake loads, which need not be taken less than Ro multiplied by the minimum lateral earthquake force as determined in Article 4.1.8.11. or 4.1.8.12, as appropriate. (6) For buildings with a Type 9 irregularity as described in Table 4.1.8.6. and where IEFaSa(0.2) is equal to or greater than 0.5, deflections determined in accordance with Article 4.1.8.13. shall be multiplied by 1.2. (7) Structures where the value of α, as determined in accordance with Sentence (5), exceeds twice the limits in Table 4.1.8.6. for a Type 9 irregularity, and where IEFaSa(0.2) is equal to or greater than 0.5 are not permitted unless determined to be acceptable based on non-linear dynamic analysis studies.
Notes to Table 4.1.8.11.E.:
4.1.8.13. Deflections and Drift Limits (1) Except as provided in Sentences (5) and (6), lateral deflections of a structure shall be calculated in accordance with the loads and requirements defined in this Subsection. (2) Lateral deflections obtained from a linear elastic analysis using the methods given in Articles 4.1.8.11. and 4.1.8.12. and incorporating the effects of torsion, including accidental torsional moments, shall be multiplied by RdRo/IE
and increased as required by Sentences 4.1.8.10.(6) and 4.1.8.16.(1) to give realistic values of anticipated deflections. (3) Based on the lateral deflections calculated in Sentences (2), (5) and (6), the largest interstorey deflection at any level shall be limited to 0.01 hs for post-disaster buildings, 0.02 hs
for High Importance Category buildings, and 0.025 hs
for all other buildings. (4) The deflections calculated in Sentence (2) shall be used to account for sway effects as required by Sentence 4.1.3.2.(12). (5) The lateral deflections of a seismically isolated structure shall be calculated in accordance with Article 4.1.8.20. (6) The lateral deflections of a structure with supplemental energy dissipation shall be calculated in accordance with Article 4.1.8.22.
Notes to Table 4.1.8.11.E.:
4.1.8.14. Structural Separation (1) Adjacent structures shall be, (a) separated by a distance equal to at least the square root of the sum of the squares of their individual deflections calculated in Sentence 4.1.8.13.(2), or (b) connected to each other. (2) The method of connection required in Sentence (1) shall take into account the mass, stiffness, strength, ductility and anticipated motion of the connected buildings and the character of the connection. (3) Rigidly connected buildings shall be assumed to have the lowest RdRo value of the buildings connected. (4) Buildings with non-rigid or energy-dissipating connections require special studies.
Notes to Table 4.1.8.11.E.:
4.1.8.17. Site Stability (1) The potential for slope instability and its consequences, such as slope displacement, shall be evaluated based on site-specific material properties and ground motion parameters referenced in Subsection 1.1.2., as modified by Article 4.1.8.4., and shall be taken into account in the design of the structure and its foundations.
Notes to Table 4.1.8.18.:
4.1.8.20. Seismic Isolation Design Provisions (1) The period of the isolated structure, determined using the post-yield stiffness of the isolation system in the horizontal direction under consideration, shall be greater than three times the period of the structure above the isolation interface calculated as a fixed base. (2) The isolation system shall be configured to produce a restoring force such that the lateral force at the TDD at the centre of mass of the isolated structure above the isolation interface is at least 0.025Wb
greater than the lateral force at 50% of the TDD at the same location, in each horizontal direction, where Wb is the portion of W above the isolation interface. (3) The values of storey shears, storey forces, member forces, and deflections used in the design of all structural framing elements and components of the isolation system shall be obtained from analysis conforming to Sentence 4.1.8.19.(3) using one of the following values, whichever produces the most critical effect: (a) mean plus IE times the standard deviation of the results of all Non-linear Dynamic Analyses, or (b)   times the mean of the results of all Non-linear Dynamic Analyses. (4) The force-deformation and damping characteristics of the isolation system used in the analysis and design of the seismically isolated structures shall be validated by testing at least two full-size specimens of each predominant type and size of isolator unit of the isolation system, which shall include, (a) the individual isolator units, (b) separate supplemental damping devices, if used, and (c) separate sacrificial wind-restraint systems, if used. (5) The force-deformation characteristics and damping value of a representative sample of the isolator units installed in the building
shall be validated by tests prior to their installation. (6) A diaphragm or horizontal structural elements shall provide continuity immediately above the isolation interface to transmit forces due to non-uniform ground motions from one part of the structure to another. (7) All structural framing elements shall be designed for the forces described in Sentence (3) with RdRo= 1.0, except, (a) for structures with IE
< 1.5, all the SFRS shall be detailed in accordance with the requirements for Rd ≥ 1.5 and the applicable referenced design standards, and (b) for structures with IE
= 1.5, all the SFRS shall be detailed in accordance with the requirements for Rd ≥ 2.0 and the applicable referenced design standards. (8) The height restrictions noted in Table 4.1.8.9. need not apply to seismically isolated structures. (9) All isolator units shall be, (a) designed for the forces described in Sentence (3), and (b) able to accommodate the TDD determined at the specific location of each isolator unit. (10) The isolation system, including a separate wind-restraint system if used, shall limit lateral displacement due to wind loads across the isolation interface to a value equal to that required for the least storey
height in accordance with Sentence 4.1.3.5.(3).
Notes to Table 4.1.8.18.:
4.2.1.1. Application (1) This Section applies to excavations and foundation
systems for buildings. 4.2.2. Subsurface Investigations and Reviews
Notes to Table 4.1.8.18.:
4.2.2.1. Subsurface Investigation (1) A subsurface investigation, including groundwater
conditions, shall be carried out, by or under the direction of a person having knowledge and experience in planning and executing such investigations to a degree appropriate for the building and its use, the ground and the surrounding site conditions.