18 - Friday, July 29, 1994 - North S ie ma “ Cracks Fallen rock petetbovage. hore News Know how your home could stand up to a quake Cracks Buiging of slope, Potential Slope Failures BUILDINGS LOCATED on or below a steep sfope could be in danger of damage from landslides during an earthquake. EARTHQUAKE DAMAGE is typically concentrated in loca- tions that can be identified in advance: GUAKE TIPS By Ross Petersen © Areas nearest to the fault seg- ments that are likely to move (not well known in this area); C Areas of soft soils where shaking is increased; and © Areas wheie the ground may set- tle or slide. Failure of the ground Curing an earthquake can happen in many ways. Cracks can ry the ground * near the slipped segments of the earthquake fault (more common in California where faults are at or near the surface). Landslides are likely on steep slopes, especially if an earthquake hits during the rainy season. Soft ground — like that found around the margins of Burrard Inlet —~ may settle during shaking. Soils on the North Shore can be Categorized as follows: 66 In some cases, building construction has magnified the probiem by increasing the instability. 99 . Poor Deep loose sand, silty clays, sand and gravel, and soft, saturated gran- ulated soils. Earthquake forces are amplified on water-saturated soils, when the soil changes from a solid to a liquid. The quicksand effect makes the ground incapable of supporting a foundation. The ground can crack or heave, causing uneven settling or building collapse. Good Bedrock (deep and unbroken rock formations) and stiff soils. These soils types are the best, since , Much less vibration is transferred through the foundation (to the struc- ture above. Damage in the marina district of San Francisco during the Loma Prieta earthquake of Oct. 17, 1989 shows how soft soils aggravate problem; this area sustained major damage even though it was more than 50 miles north of the fault seg- ment that slipped in the Santa Cruz mountains. The marina district is an area underlain by mud nearly a hundred feet thick with a layer of sand applied to the surface. Techniques have been developed in the past few decades to engineer such landfills to reduce the chance of liquefaction and ground failure during earthquakes. Newer buildings built on such engincered landfills are likely to sustain much less shaking and damage in strong earthquakes. Even so, we should acknow- ledge that we have such areas of weak soils on the North Shore and should expect stronger shaking and perhaps soil failure in the areas along our waterfront, and on the river delta deposits at the mouths of the Capilano and Seymour rivers. Landslides should be of concern to those North Shore residents who live on or below steep unstable slopes. In some cases, building con- struction has magnified the problem by increasing the instability. Also, some buildings were not designed with ground slippage in mind, and have parts or all of their foundations susceptible to carth- quake induced ground failure. Many of these sites are obvious (creek or river banks, and the upper elevations of our residential devel- opment); but it will be up to proper- ty owners to assess their own vulner- ability to slope failure and potential damage to buildings. The North Shore municipalities are completing an overview map- ping of the entire North Shore with respect to soils types and slope sta- bility for purposes of earthquake ) 1959 ALDERLYNN DR., NORTH VANCOUVER planning. When completed, this information will be made avaiiable to the public. Ross Peterson is the coordinator of the North and West Vancouver emergency program, SAFE LTD PREPARE FOR AN INSPECTIONS — ANALYSIS ; ' REPORTS AND PROBLEM SOLVING SAFETY AND SURVIVAL SUPPLIES CALL NOW. TEL: 980-9900 / FAX: 987-0642 : What’s happening in our District ublic Hearings are scheduled to provide an opportunity for Council to hear from those who believe their interest in property may be affected by changes to these bylaws, as ’ outlined below. Date: Time: Location: 7:00 p.m. Tuesday, August 9, 1994 Council Chamber of Municipal Hall 355 West Queens Road, North Vancouver a BYLAW 6630 - “Rezoning Bylaw 993” Applicant: The Corporation of the District of North Vancouver Proposed Text Amendment: To amend the definition of “residential building, multiple-family townhouse”, include commercial purposes as a permitted use in RL Zones and allow detached units in the RM3 Zone. To further refine the residential regulations enacted under Bylaw 6543. BYLAW 6682 - “District of North Vancouver Subdivision Control! Bylaw, 1956, Amending Bylaw 39” Applicant: Subject Land: The Ditton Group on behalf of the owners, Mr. ‘ and Mrs. Rohne. Lot C of Lots 1 to 8, Block C, District Lot 785, Plan 4730 (4195 St. Georges Avenue, as shown on following map). Proposed Amendment: To amend the Subdivision Control Bylaw to establish lot size regulations attributable only to the lot at 4195 St. Georges Avenue. AVENUES PAULS Purpose: {5.2m }i5.2m AVéNUS WOODDALE ROAD PROP GSEO S5UB0 1 VA SION To allow for the subdivision of 4195 St. Georges Avenue into two lots consistent with the surrounding lot pattern. All persons who believe their interest in property may be affected by the above proposals will be afforded an opportunity to be heard in person and/or by written submission. Written submissions will be accepted up to the conclusion of the Public Hearings. These Public Hearings are held under the provisions of the Municipal Act. Copies of the bylaws, resolutions, supporting staff reports and any relevant background material are available for review at the District of North Vancouver Legislative Services Department or Planning Department, at the Municipal Hall, 355 West Queens Road. Monday through Friday, except Statutory Holidays, July 29, 1994 to August 9, 1994, inclusive, between the hours of 8:30 a.m.and 4:30 p.m. Agnes S. Hilsen Deputy Municipal Clerk July 29, 1994