Back4.1.8.11.(3)

ATTRIBUTION:

Functional Statement:

F20

To support and withstand expected loads and forces.

Objective:

OS2.1

 

APPLICATION:

Fundamental lateral period of vibration of the building structure, Ta, to be used in calculating the design spectral response acceleration, S(T), in Sentence 4.1.8.4.(6).
This applies to buildings described in Sentence 1.3.3.2.(1) of Division A and to buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9] that are required to be designed in accordance with the requirements of Part 4.

INTENT:

To limit the probability that the calculation of loads due to earthquake will not take into account how the expected fundamental lateral period of the building structure affects the seismic forces and displacements in the structure due to the seismic ground motions, which could lead to structural failure, which could lead to harm to persons.

ATTRIBUTION:

Functional Statement:

F20

To support and withstand expected loads and forces.

F22

To limit movement under expected loads and forces.

Objective:

OP2.1, OP2.4

 

APPLICATION:

Fundamental lateral period of vibration of the building structure, Ta, to be used in calculating the design spectral response acceleration, S(T), in Sentence 4.1.8.4.(6).
This applies to buildings described in Sentence 1.3.3.2.(1) of Division A and to buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9] that are required to be designed in accordance with the requirements of Part 4.

INTENT:

To limit the probability that the calculation of loads due to earthquake will not take into account how the expected fundamental lateral period of the building structure affects the seismic forces and displacements in the structure due to the seismic ground motions, which could lead to:
  • the excessive deformation of, or excessive stress in, the structural elements, which could lead to damage to the building, or
  • the excessive deformation of, or excessive stress in, the building structure, which could lead to damage to the building, which could impede the intended use and occupancy of the building.

ATTRIBUTION:

Most technical provisions of the BC Fire Code describe how the code’s objectives and functional statements are achieved. However, some provisions, like this one, do not relate directly to a code objective. The following analysis is provided to assist in understanding of the provision.

 

APPLICATION:

Deflections calculated when other established methods of mechanics described in Clause 4.1.8.11.(3)(d) are used to determine the fundamental lateral period.
This applies to buildings described in Sentence 1.3.3.2.(1) of Division A and to buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9] that are required to be designed in accordance with the requirements of Part 4.

INTENT:

To supersede the application of Subclauses 4.1.8.11.(3)(d)(i), (b) and (c) and allow the use of the period determined without the upper limit specified therein so that the model used to calculate the deflections is the same as that used to compute the period.