Geotechnical Field Review - Ryzuk Geotechnical

Geotechnical Field Review / Site Instruction

Project No: 8-8509-1 Project: Proposed Retaining Wall - 4 Governors Point Road, View Royal, BC Client: Mike Pawlak Contact: see above Email / Fax No: Date: October 9, 2017

As requested, we attended the referenced site on September 27, 2017, to carry out a review of the construction of a proposed rock and mortar retaining wall along the shoreline frontage of the property, well above the Present Natural Boundary. We understand that the work has been stopped by the Township of View Royal since the construction has been carried out thus far without a building permit. The building department has specified that a geotechnical review is required at this time, and we herein provide our associated observations, comments, and recommendations in this regard. Our work has been carried out in accordance with, and is subject to, the attached Terms of Engagement.

At the time of our visit the rock and mortar retaining wall had been constructed to nearly a completed final elevation, being up to approximately 2.4 meters in height. The wall had only been partially backfilled and therefore we were able to review portions of the backside of the mortared rock wall. We understand that the wall was constructed atop an existing stacked boulder wall which was installed contemporary with your purchase of the house, being some 14 years ago. You indicated that the base of the wall was extended such that the thickness of the mortared rock is in the order of 2/3 minimum of the proposed height of the wall along the entire length, as per the wall builders approach. We observed drain rock backfill behind the wall, and several 25 mm diameter weep pipes were in place providing drainage conduits from the backfill to the face of the wall. We noted that the rock and cement mortar construction appeared to have been carried out with appropriate construction methodology and the construction appeared to be reasonably robust.

We understand that the remaining work will be to place and compact drain rock fill and with some local mixed coarse rock from breaking up of the upper layer of boulders such that the adjacent paving stone patio can be extended out to the crest of the new wall. We recommend that a medium to heavy weight non-woven geotextile fabric be placed over top of the free draining coarse rock and drain rock fill such that a layer of crushed screenings can be placed over top being in the order of 100 mm thickness to provide a base support for the extended area of the patio.

Based on the above, we consider the proposed retaining wall has been constructed in general accordance with geotechnical recommendations. We will review the remaining aspects of the installation and the final configuration of the wall. We trust the preceding is suitable for your current requirements. Please contact us if you have any questions or concerns and to schedule for a return inspection and please forward photographs of the subsequent work in the interim.

Kind regards,

Andrew Jackson, P.Geo. Geoscientist

Attached – Terms of Engagement