Warning This information has been archived because it is outdated and no longer relevant.

Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards. As per the Communications Policy of the Government of Canada, you can request alternate formats on the "Contact Us" page.

4.1.8.11.(8)
ApplicationIntent
OS2OP2OS2OP2
ObjectiveOP2 Structural Sufficiency of the Building
Attribution
(b) [F20-OP2.1] [F22-OP2.4]
Application
Application 1: 
Torsional effects in buildings due to accidental eccentricities.
Exceptions: 
except as stated in Sentence 4.1.8.1.(1), which applies to areas where the spectral response acceleration amplified for site conditions equals the floor levels found in low seismicity regions with Site Class C (i.e. very dense soil and soft rock).
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.
Top of Page
Intent
Intent 1: 
To limit the probability that the calculation of loads due to earthquake will not take into account the forces due to expected seismic torsional moment at any level of the building, taking into account uncertainty in the determination of the centre of mass and centre of stiffness, inaccuracy in the measurement of the dimensions of structural elements, variations in material properties, or rotational ground motion, 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.
Intent 2: 
To clarify that torsional effects are to be addressed concurrently with the static loads determined in Sentence 4.1.8.11.(6).
Intent 3: 
To direct Code users to Sentence 4.1.8.11.(10) for the calculation of torsional loads.
Top of Page