Eng notice of completion of Carport-Ret Wall-Seismic.pdfTo: Jeannine Graf, Bldg Official, Ann Bullis Assistant Bldg Official Date: July 27, 2007
City of Edmonds, Building Division
From: Mark Heinzig, PE Heinzig Enterprises, Inc.
CC: Monte Clouston, Property Owner, Bend RECEIVED
Project: Calais Apartment's Carport Repairs,1115 4`' Ave S Edmonds, WA JUL 3 0 2001
Re: Owner/Contractor Completion of circa 2006 Carport Seismic/Retaining Wall Upgrade
BUILDING DEPAR Y MEN.7
Ref Plans: PE stamped, Permit Approved Calais Seismic Rehab Drawings, Dated 7/8/06 CITY OF EDMONDs
Rehab Repairs by: Monte Clouston, et al (Property Owner & Builder, his subcontractors & workers)
As E.O.R. for the Calais Carport Seismic Rehab of 2006, I am writing this engineer letter to inform the City of Edmonds that
Monte Clouston (Owner/Contractor) has satisfactorily completed the voluntary, partial seismic upgrade & associated retaining
wall repairs for the Carport in general conformance with the design intent of the PE stamped, permit approved Calais Carport
Seismic Rehab Drawings, dated 7/8/06 & (construction phase) E.O.R field repair details, both prepared by Mark Heinzig,
Heinzig Enterprises, Inc. (It is my understanding the structural upgrade was undertaken by the Owner as a prelude to a rental -to -
condo conversion, and this letter & completed repairs should satisfy the requirements of WA State Housing Bill, EHB 1848.)
As an aside, the Owner & I noted that a portion of the existing (8" thick x approx 8' ht) cone. retaining wall at the SE corner of
the Carport (to remain in place) is approx 1.75"-2" out of `vertical plumb'. This is equivalent to an approx 1.2 degree wall
rotation. As discussed below, both I and project geo-engineer (Bob Pride,PE.), as well as the Edmonds Building Depart official
have reviewed the wall, and agree that the wall rotation is most likely due to the existing retaining wall being cast -in-place `out of
plumb', not due to post -construction retaining wall failure, or assoc. footing failure. However, this retaining wall should be
periodically monitored, and if any future wall rotation or wall cracks occur, notify a WA PE engineer for further investigation.
While it is my opinion that the circa 2007 Calais Carport structural repairs (that I field observed & inspected) were installed in
general conformance with the design intent of the permit approved engineering plans, I am not responsible for any acts or
omission of the Owner/contractor or subcontractor providing any portion of work on this building. Nor am I providing any direct
or implied construction warranty on the repairs. Finally, while I am confident my (permit approved) engineering design meets
relevant code requirements, I am not responsible for, nor providing any guarantee on the existing condition (or expected future
structural performance) of the existing building's structural system, or existing retaining wall's
These items were historically designed/installed by others, remained concealed from my visual
of engineering services on this project.
Respectfully yours,
Mark Heinzig, PE
Heinzig Enterprises, Inc.
425-208-6877 cel, Heinzig@MSN.com
concealed structural elements.
inspection & are beyond my scope
M
Investigation of Cause of (E) Carport SE Corner Retaining Wall Rotation:
I (Mark Heinzig) did not observe any evidence of foundation distress on the exposed west side of the suhj H sr ver (ie, no flexural
cracks in stem wall on the West side). However, I did field observed an in-situ gravel blanket & 4" diameter perforated fig drain behind the existing retaining
wall, consistent with contract drawings. This would indicate a free draining condition exists behind the existing retaining wall, which is equivalent to approx 35
pcf (equivalent fluid pressure). I could not visually inspect the concealed footings or stem -footing attachment (both concealed by backfill/dirt & slab). Therefore
I could not determine if there was any foot distress, nor whether the footings were installed per contract drawings, nor whether the vertical stem flexural
reinforcement was properly installed. However, I did confirm that the historic design (of flexural reinforcement) was of sufficient strength for a retained soil
height of approx 7' ft retained ht (for a lateral soil pressure of 35 pcf), though the associated soil pressures exceeded the historic design values, and the ftgs were
slightly undersized, accordingly. However, according to project geo-engineer, Mr. Bob Pride, PE, the site soils are capable of greater than 5000 psf allowable
bearing pressures. I also field observed that the existing/historic retaining wall sole plate (directly anchored to the top of the cast in-place retaining wall) was
installed `off -set'; that would suggest that the retaining wall was cast `out of plumb', and that the contractor needed to compensate, to obtain a `true rectangular'
footprint that matched the roof system footprint. Also, I observed that the existing truss system was directly attached to the retaining walls's sole plate. (Per the
Owner/Contractor, the roof system was historically installed within 1-2 weeks maximum after the pour of the subject retaining wall). 'Therefore, any lateral wall
movement/rotation would show up as lateral truss movement on support bins. And, on July 18, 2007, the Owner & I field observed a max of 3/16 "-'/d' lateral
wall movement of the truss -system on the adjacent post -beam system.
Taken together, this would suggest that at most, approx (2-1.75/2)x100 =12.5% of the retaining wall's lateral movement or wall rotation may have occurred
post -construction. Though it is more likely that either 88% or more of the retaining wall rotation occurred prior to the roof install, or was due to an `out of plumb'
form, not due a post -construction wall or footing failure. The Owner, the geo-engineer, building official, and I all believe the `out of plumy form is the most
likely reason for the out -of -plumb wall_ However, this retaining wall should be periodically monitored, and if any future wall rotation or wall cracks occur, notify
a WA PE engineer for further investigation.