Appendix A — Division B

Explanatory Material

A-4.1.1.3.(1) Structural Integrity

The requirements of Part 4, including the CSA design standards, generally provide a satisfactory level of structural integrity. Additional considerations may, however, be required for building systems made of components of different materials, whose interconnection is not covered by existing CSA design standards, buildings outside the scope of existing CSA design standards, and buildings exposed to severe accidental loads such as vehicle impact or explosion. Further guidance can be found in the Commentary entitled Structural Integrity in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.1.3.(2) Serviceability

Information on serviceability can be found in the Commentary entitled Deflection and Vibration Criteria for Serviceability and Fatigue Limit States in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.1.5.(2) Structural Equivalents

Sentence 4.1.1.5.(2) provides for the use of design methods not specified in Part 4, including full-scale testing and model analogues. This provision is usually used to permit the acceptance of new and innovative structures or to permit the acceptance of model tests such as those used to determine structural behaviour, or snow or wind loads. Sentence 4.1.1.5.(2) specifically requires that the level of safety and performance be at least equivalent to that provided by design to Part 4 and requires that loads and designs conform to Section 4.1.

Sentence 4.1.1.5.(2) and the provision for alternative solutions stated in Clause 1.2.1.1.(1)(b) of Division A are not intended to allow structural design using design standards other than those listed in Part 4. The acceptance of structures that have been designed to other design standards would require the designer to prove to the appropriate authority that the structure provides the level of safety and performance required by Clause 1.2.1.1.(1)(b) of Division A. The equivalence of safety and performance can only be established by analyzing the structure for the loads and load factors set out in Section 4.1. and by demonstrating that the structure at least meets the requirements of the design standards listed in Sections 4.3. and 4.4.

A-4.1.2.1. Loads and Effects

Information on the definitions can be found in the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.2.1.(1) Temperature Changes

Information on effects due to temperature changes can be found in the Commentary entitled Effects of Deformations in Building Components in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.2.1.(3) Major Occupancies

In a building containing more than one major occupancy and classified in more than one Importance Category, the classification of each independent structural system shall be the same as for any part of the building that is dependent on that structural system and for the highest usage group according to Table 4.1.2.1.

A-Table 4.1.2.1. Importance Categories for Buildings

Low Importance Category Buildings

Low human-occupancy farm buildings are defined in the National Farm Building Code of Canada 1995 as having an occupant load of 1 person or less per 40 m² of floor area. Minor storage buildings include only those storage buildings that represent a low direct or indirect hazard to human life in the event of structural failure, either because people are unlikely to be affected by structural failure, or because structural failure causing damage to materials or equipment does not present a direct threat to human life.

Buildings Containing Hazardous Materials

The following buildings contain sufficient quantities of toxic, explosive or other hazardous substances to be classified in the High Importance Category of use and occupancy:

petrochemical facilities,
fuel storage facilities (other than those required for post-disaster use), and
manufacturing or storage facilities for dangerous goods.

The following types of buildings may be classified in the Normal Importance Category: buildings that are equipped with secondary containment of toxic, explosive or other hazardous substances, including but not limited to, double-wall tanks, dikes of sufficient size to contain a spill, or other means to contain a spill or a blast within the property boundary of the facility and prevent the release of harmful quantities of contaminants to the air, soil, groundwater, surface water or atmosphere, as the case may be.

A-4.1.3. Limit States Design

Information on limit states design can be found in the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.2.(2) Load Combinations

Load Combination change begin

Equations

The load combinations in Tables 4.1.3.2.A change begin

and 4.1.3.2.B

apply to most situations for loadbearing building structures. Guidance on special situations such as load combinations for fire resistance and building envelopes is given in the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

Load Cases and Crane Load Effects

The load combinations in Table 4.1.3.2.A are to be evaluated for structures with crane load effects for the scenario where the crane loads are zero, and for structures without crane loads. The load combinations in Table 4.1.3.2.B are to be evaluated for structures with crane loads for the scenario where the crane load effects are other than zero.

Crane Loads

Crane-supporting structures that have cranes in multiple parallel bays should be designed for the maximum vertical crane load with the cranes positioned for the most critical effect in conjunction with a lateral load with each crane in turn positioned for the most critical effect. For load combinations that include crane loads, additional guidance can be found in CISC 2009, “Crane-Supporting Steel Structures: Design Guide.”

A-4.1.3.2.(4) Effects of Lateral Earth Pressure, H, Pre-stress, P, and Imposed Deformation, T, in Design Calculations

Effects of Lateral Earth Pressure, H, in Design Calculations

For common building structures below ground level, such as walls, columns and frames, 1.5 H is added to load combinations 2 to 4. For cantilever retaining wall structures, see the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

Effects of Pre-stress, P, and Imposed Deformation, T, in Design Calculations

For structures and building envelopes designed in accordance with the requirements specified in the standards listed in Section 4.3., with the exception of Clauses 8 and 18 of CAN/CSA-A23.3, P and T need not be included in the load combinations of Table 4.1.3.2.A For structures not within the scope of the standards listed in Section 4.3., including building envelopes, P and T must be taken into account in the design calculations. For recommended load combinations including T, see the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.2.(5) Overturning, Uplift or Sliding

Information on overturning, uplift and sliding can be found in the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.3.(1) Failure due to Fatigue

Failure due to fatigue of building structures referred to in Section 4.3. and designed for serviceability in accordance with Article 4.1.3.6. is, in general, unlikely except for girders supporting heavily used cranes, on which Article 4.1.5.11. provides guidance.

A-4.1.3.3.(2) Vibration Effects

Guidance on vibration effects can be found in the Commentary entitled Deflection and Vibration Criteria for Serviceability and Fatigue Limit States in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.4.(1) Loads and Load Combinations for Serviceability

The loads and load combinations for serviceability depend on the serviceability limit states and on the properties of the structural materials. Information on loads and load combinations for the serviceability limit states, other than those controlled by deflection, can be found in the Commentary entitled Deflection and Vibration Criteria for Serviceability and Fatigue Limit States in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.5.(1) Deflections

Serviceability criteria for deflections that cause damage to non-structural building components can be found in the standards listed in Section 4.3. Information on deflections can be found in the Commentary entitled Deflection and Vibration Criteria for Serviceability and Fatigue Limit States in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B). Information on loads and load combinations for calculating deflection can be found in the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.5.(3) Lateral Deflection of Buildings

The limitation of 1/500 drift per storey may be exceeded if it can be established that the drift as calculated will not result in damage to non-structural elements. Information on lateral deflection can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.6.(1) Floor Vibration

Information on floor vibration can be found in the Commentary entitled Deflection and Vibration Criteria for Serviceability and Fatigue Limit States in the User's Guide - NBC 2010, Structural Commentaries (Part 4 of Division B). Information on loads and load combinations for the calculation of vibration can be found in the Commentary entitled Limit States Design in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.6.(2) Dynamic Analyses of Floor Vibrations

Information on a dynamic analysis of floor vibrations from rhythmic activities can be found in the Commentary entitled Deflection and Vibration Criteria for Serviceability and Fatigue Limit States in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.3.6.(3) Lateral Vibration Under Wind Load

Information on lateral vibrations and accelerations under dynamic wind loads can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.4.1.(6) Counteracting Dead Load Due to Soil

Examples of structures that traditionally employ the dead load of soil to resist loadings are pylon signs, tower structures, retaining walls, and deadmen, which resist wind uplift and overturning in light structures.

A-4.1.5.1.(1) Loads Due to Use of Floors and Roofs

In many areas of buildings, such as equipment areas, service rooms, factories, storage areas, warehouses, museums, and office filing areas, live loads due to their intended use may exceed the minimum specified loads listed in Table 4.1.5.3. In these instances, the probable live load shall be calculated and used as the specified live load for the design of that particular area.

A-Table 4.1.5.3. Considerations for Live Loads

Arenas, Grandstands and Stadia

The designer should give special consideration to the effects of vibration.

Attics - Limited Accessibility

Attic live loading is not required when the ceiling below the attic consists of removable panels that permit access to the ceiling space without loading the ceiling supporting members. Attic live loading is not required in any area of the attic where the least dimension of the attic space is less than 500 mm.

Corridors, Aisles and Rows of Seats

The spaces between rows of seats are typically designed for the loads of the occupancy they serve. Rows of seats typically discharge into aisles that are designed for the loads used for the rows of seats. Corridors have a minimum width of 1 100 mm and may serve as collectors for aisles; they are therefore part of the exit system and are required to be designed for a minimum live load of 4.8 kPa.

Floor Areas That Could Be Used As Viewing Areas

Some interior balconies, mezzanines, corridors, lobbies and aisles that are not intended to be used by an assembly of people as viewing areas are sometimes used as such; consequently, they are subject to loadings much higher than those for the occupancies they serve. Floor areas that may be subject to such higher loads must, therefore, be designed for a loading of 4.8 kPa.

Lecture Halls and Classrooms

For the purposes of applying the requirements of Table 4.1.5.3., lecture halls with fixed seats are similar to theatres in configuration (the seats may have a writing tablet affixed to one arm). Classrooms are typically furnished with full-sized desks having separate or integrated seats.

Minimum Roof Live Load

Articles 4.1.5.3. and 4.1.5.9. stipulate a minimum uniform roof live load of 1.0 kPa and a minimum concentrated live load of 1.3 kN. These live loads are “use and occupancy loads” intended to provide for maintenance loadings: they are not reduced as a function of area or as a function of the roof slope due to their variability in distribution and location.

Vehicle Loads

A special study should be undertaken to determine the distributed loads to be used for the design of floors and areas used by vehicles exceeding 9 000 kg gross weight and of driveways and sidewalks over areaways and basements. Where appropriate, the designer should refer to CAN/CSA-S6, “Canadian Highway Bridge Design Code.”

A-4.1.5.5. Loads on Exterior Areas

In Article 4.1.5.5., “accessible” refers to the lack of a physical barrier that prevents or restricts access by vehicles or persons to the site in the context of the specific use.

A-4.1.5.8. Tributary Area

Information on tributary area can be found in the Commentary change begin

entitled Live Loads

in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

contentHistory

A-Table 4.1.5.9. Loads Due to Concentrations

Special study is required to determine concentrated loads for the design of floors and areas used by vehicles exceeding 9 000 kg gross weight, and of driveways and sidewalks over areaways and basements. Where appropriate the designer should refer to CAN/CSA-S6, “Canadian Highway Bridge Design Code.”

A-4.1.5.11. Crane-Supporting Structures

Guidance on crane-supporting structures can be found in CSA S16, “Design of Steel Structures.”

A-4.1.5.14. and 4.1.5.15.(1) Design of Guards

In the design of guards, due consideration should be given to the durability of the members and their connections.

A-4.1.5.17. Loads on Firewalls

Information on loads on firewalls can be found in the Commentary entitled Structural Integrity of Firewalls in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.6.2. Coefficients for Snow Loads on Roofs

Information on coefficients for snow loads on roofs can be found in the Commentary entitled Snow Loads in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.6.2.(4)(b) Unit Weight of Snow

Information on the unit weight of snow can be found in the Commentary entitled Snow Loads in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.6.3.(2) Full and Partial Loading under Snow Loads

Information on full and partial snow loading on roofs can be found in the Commentary entitled Snow Loads in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.6.4.(1) Rain Loads

Information on rain loads can be found in the Commentary entitled Rain Loads in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.6.4.(3) Flow Control Drains

Book II (Plumbing Systems) of the British Columbia Building Code

contains requirements regarding the use of flow control roof drains. The designer must ensure that the building complies with change begin

both the Book I and Book II of the Code

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A-4.1.7.1.(1) to (3) Pressure Coefficients for Wind Loads

Information on pressure coefficients can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.1.(5)(a) to (c) Simple Procedure for Calculating C_e

Information on the simple procedure for calculating C_e can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.1.(5)(d) Dynamic Approach for Wind Loads

Information on a dynamic approach can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.1.(6)(a) Gust Effect Factor for the Building as a Whole and Main Structural Members

Information on the gust effect factor for the building as a whole and for the main structural members can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.1.(6)(c) Gust Factors for Calculation of Internal Pressures

Information on gust factors for the calculation of internal pressures can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.1.(6)(d) and 4.1.7.2.(1)(b) Dynamic Approach to the Action of Wind Gusts

Information on a dynamic approach to the action of wind gusts can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.2.(1) and (2) Natural Frequency

Information on calculating the natural frequency of a building can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.7.3.(1) Full and Partial Loading under Wind Loads

Information on full and partial loading under wind loads can be found in the Commentary entitled Wind Load and Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.2.(1) Notation

Definition of e_x

Information on the calculation of torsional moments can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

Definition of W

Information on the definition of dead load, W, can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.3.(4) General Design of the SFRS

Information on the general design requirements for the SFRS can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.3.(6) General Design of Stiff Elements

Information on the general design requirements for stiff elements can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.3.(7)(b) and (c) Stiffness Imparted to the Structure from Elements Not Part of the SFRS

Information on stiffness imparted to the structure from elements not part of the SFRS can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.3.(8) Structural Modelling

Information on structural modelling can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.4.(3) and Table 4.1.8.4.A. Site Class

Information on Site Class can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-Table 4.1.8.5. Serviceability Limit States for Earthquake

Information on serviceability limit states for earthquake can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-Table 4.1.8.6. Structural Irregularities

Information on structural irregularities can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.7.(1) Dynamic Analysis Procedures

Information on dynamic analysis procedures can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.9.(4) Vertical Variations in R_dR_o

Information on vertical variations in R_dR_o can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.9.(5) R_dR_o and Equivalent Systems

Information on the R_dR_o of equivalent systems can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.11.(3) Determination of the Fundamental Period, T_a

Information on the determination of the fundamental period, T_a, can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.12.(1)(a) Linear Dynamic Analysis

Information on Linear Dynamic Analysis can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.12.(1)(b) Non-linear Dynamic Analysis

Information on Non-linear Dynamic Analysis can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.12.(3) Ground Motion Histories

Information on ground motion histories can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.12.(4)(a) Accidental Torsional Moments

Information on accidental torsional moments can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.13.(4) Deflections and Sway Effects

Information on deflections and sway effects can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.15.(1) Diaphragms and their Connections

Information on diaphragms and their connections can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.15.(3) Ductile Diaphragms

Information on the design of struts, collectors, chords and connections for ductile diaphragms can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.15.(4) Discontinuities

Information on elements supporting discontinuities can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.15.(5) Vertical Variations in R_dR_o

Information on elements of the SFRS below the variation in R_dR_o can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.15.(6) Concurrent Yielding

Information on the effects of concurrent yielding of elements can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.15.(7) Design Force in Elements

Information on the design force in elements can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.16.(1) Rocking Foundations

Information on foundations that are allowed to rock can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.16.(3)(a) Interconnection of Foundation Elements

Information on the interconnection of piles or pile caps, drilled piers, and caissons can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.16.(4) Earthquake Lateral Pressures from Backfill or Natural Ground

Information on methods of computing the seismic lateral pressures from backfill or natural ground can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.16.(5)(a) Cyclic Inelastic Behaviour of Foundation Elements

Information on the cyclic inelastic behaviour of piles or pile caps, drilled piers, and caissons can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.16.(6) Alternative Foundation Ties

Alternative methods of tying foundations together, such as a properly reinforced floor slab capable of resisting the required tension and compression forces, may be used. Passive soil pressure against buried pile caps may not be used to resist these forces.

A-4.1.8.16.(7) Liquefaction

Information on liquefaction can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.17.(1) Slope Stability

Information on slope instability can be found in the Commentary entitled Design for Seismic Effects in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.1.8.18. Elements of Structures, Non-structural Components and Equipment

Information on the requirements of Article 4.1.8.18. can be found in the Commentary entitled Design for Seismic Effects in the User’s Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.2.2.1.(1) Subsurface Investigation

Where acceptable information on subsurface conditions already exists, the investigation may not require further physical subsurface exploration or testing.

A-4.2.2.3.(1) Responsibilities of the Designer as Defined in Part 4

In certain situations, such as when the design is highly technical, it may be necessary for the “other suitably qualified person” to be someone responsible to the designer. In such cases the authority having jurisdiction may wish to order that the review be done by the designer.

A-4.2.4.1.(1) Innovative Designs

It is important that innovative approaches to foundation design be carried out by a person especially qualified in the specific method applied and that the design provide a level of safety and performance at least equivalent to that provided for or implicit in the design carried out by the methods referred to in Part 4. Provision must be made for monitoring the subsequent performance of such structures so that the long-term sufficiency of the design can be evaluated.

A-4.2.4.1.(3) Ultimate Limit States for Foundations

Information on ultimate limit states for foundations, including terminology and resistance factors, can be found in the Commentary entitled Foundations in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.2.4.1.(5) Design of Foundations for Differential Movements

Information on the design of foundations for differential movements can be found in the Commentary entitled Foundations in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.2.4.4.(1) Depth of Foundations

When adfreezing has occurred and subsequent freezing results in soil expansion beneath this area, the resulting uplift effect is sometimes referred to as frost jacking.

A heated building that is insulated to prevent heat loss through the foundation walls should be considered as an unheated structure unless the effect of the insulation is taken into account in determining the maximum depth of frost penetration.

A-4.2.5.1.(1) Excavations

Information on excavations can be found in the Commentary entitled Foundations in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.2.6.1.(1) Shallow Foundations

Information on shallow foundations can be found in the Commentary entitled Foundations in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.2.7.1.(1) Deep Foundation Units

A deep foundation unit can be pre-manufactured or cast-in-place; it can be driven, jacked, jetted, screwed, bored or excavated; it can be of wood, concrete or steel or a combination thereof.

A-4.2.7.2.(1) Deep Foundations

Information on deep foundations can be found in the Commentary entitled Foundations in the User's Guide – NBC 2010, Structural Commentaries (Part 4 of Division B).

A-4.2.7.2.(2) Load Testing of Piles

ASTM D 1143, “Deep Foundations Under Static Axial Compressive Load,” defines routine load test procedures that have been extensively used.

A-4.3.3.1.(1) Precast Concrete

CAN/CSA-A23.3, “Design of Concrete Structures,” requires precast concrete members to conform to CSA A23.4, “Precast Concrete – Materials and Construction.”

A-4.3.4.1.(1) Welded Construction

Qualification for fabricators and erectors of welded construction is found in Clause 24.3 of CSA S16, “Design of Steel Structures.”

A-4.3.4.2.(1) Cold-Formed Stainless Steel Members

There is currently no Canadian standard for the design of cold-formed stainless steel structural members. As an interim measure, design may be carried out using the limit states design provisions of SEI/ASCE 8, “Design of Cold-Formed Stainless Steel Structural Members,” except that load factors, load combinations and load combination factors shall be in accordance with Subsection 4.1.3.