HomeMy WebLinkAboutRose Wall Repair PD_ Memorandum
WSP USA
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Memorandum
Date: 16 November 2021
Subject: Gene Coulon Beach Park Rose Wall Repair Project Description
From: Grace Roberts, Senior Scientist, WSP USA
To: Jill Ding. Senior Planner, City of Renton Community and Economic Development
Route
To:
Alan Wyatt, Capital Projects Manager, City of Renton Parks Planning & Natural
Resources
INTRODUCTION
A June 2020 inspection of the Rose Wall bulkhead revealed a need for the repair of a split timber
post. The wall is a timber bulkhead adjacent to Lake Washington and is approximately 330 feet
in length, with Station 0+00 located on the north end of the wall and Station 3+30 located at the
south end of the wall.
The Rose Wall bulkhead is typically constructed with 8x8-treated timber posts (vertical
structural elements) spaced at 6 feet on center, with 4x8-treated timber lagging boards (horizonal
structural elements) along the face. Over the top of the timber posts are two 4x8-treated timber
cap members spanning horizontally. On the back side (landside), there are two 4x8-treated
timber members from Stations 1+00 to 3+30. From Stations 0+00 to 1+00, the wall appears to be
constructed with the same treated timber posts and lagging adjacent to the shoreline but has
additional framing and features to form the ramp to the timber platform at the sailing float.
Rose Wall Split Post Repair
At Station 2+52, the post is split full observed height, with a maximum split width of
approximately 1 inch. Repair will be completed by excavating the shore side of the post down to
the beginning of the split, approximately five feet from the top of the post (or a two-foot deep
excavation), and placing a steel plate on each side of the post and installing 1/2-inch diameter
bolts at 6-inces on center (see attached drawing).
GHR:GDN