Government Issues Regulation for Assessment of Seismic Slope Stability
On December 13, 2006, the provincial government enacted building regulation M268. The building regulation reads as follows:
“Where the intended use of the land is the construction of a building, the geotechnical study and geohazard assessment for slope stability of that land must be based on ground motion values having a 10% probability of exceedance in 50 years.”
Here, “building” has the same meaning as in the BC Building Code. This regulation came into effect December 14, 2006.
As referenced in the Commentary on Geotechnical Slope Stability (Seismic) Regulation, dated January 2, 2007, this regulation is made pursuant to Section 692(d) of the Local Government Act. Using this enabling legislation restricts the application of the regulation to only those slopes that could impact the structural safety of a building.
Materials are being developed to guide local governments and industry. The Building Policy Branch of the Office of Housing and Construction Standards has entered into discussions with APEGBC to establish practice guidelines for seismic slope stability assessments on a building that consider the influence of ground acceleration due to an earthquake. The provincial government has also extended an invitation to the Union of BC Municipalities to work with the provincial government on establishing an acceptable level of risk that a community is willing to accept.
This information was conveyed by the Building Policy Branch in Bulletin No. B06-06, dated December 14, 2006, and a subsequent commentary issued on January 2, 2007.
More information is available on the Building Policy Branch website at www.housing.gov.bc.ca/building/regs/seismic.htm.