Hidden Valley-CS050406 (2)From: "Tim Bennett'1 <tim@bennettconsultinginc.com>
To: "Rodney Louviere" <rlouviere@daa-civil.com>, "Keith Marvin"
<kmarvin@ci.coppell.tx.us>
Date: 4/6/2005 12:54:53 PM
Subject: Retaining Wall at Hidden Valley Estates
This morning, at his suggestion, I went with Keith to the site and we
examined the existing wall that has been constructed on the east side of the
properly and made measurements and observations comparing the as-built wall
to the January 18th drawing in his file. First, we observed that the wall,
while attractive in appearance, does not match the design drawing in most
respects.
We measured the slope of the wall as 2" to 2 1/2" to the foot on the front
exposed face. The top of the wall is 12" matching the drawing. If we assume
that the back side is semetrical with the exposed front, which we measured
this makes the width of the wall at the base of a 5' to 6' section 36".
The space that could be observed from the top of the excavation to the top
of the wall does not appear to be wide enough to support this assumption.
The drawing calls for the wall to have a slope of 4" to the foot front and
back which would make the width of the base of the wall an additional 2'
wider at the base than what we observed.
The drawing shows the wall extending below the lower grade a distance that
i think was 24 inches straight sided at the full width then an additional 20
inches (Dimension D) at a narrower width. We observed that the wall, as
built, does not extend below the lower grade at all, 'has no straight sided
feature to be burried at this face and has a footer or no more than 6" to 8"
depth at about 18" of width centered on the full width at the lower grade.
The wall sections we observed were at least 6" too low to allow for the 1"
in 10" maximum slope shown on the drawing to the existing upper grade for
the soil back fill at the top of the wall. We assumed that this was to allow
for the stone cap that has been proposed, but is not represented on the
drawing on file with the city.
By my estimation, 55% of the mass of the wall called for on the drawing is
missing. Gentlemen, this is a gravity wall system that depends on its mass
to withstand the forces exerted on it by the difference in grade and all
that entails. I find it difficult to believe that 55% of that mass called
for by your structural engineer can be neglected without degrading whatever
safety factor he built into his design to an unacceptable degree. This puts
my property at risk, which is unacceptable.
Tim Bennett
CC: "Bob Benes" <bodoelem2@yahoo.com>, "Kenric R. Hevron" <khevron@comcast.net>,
"Jeff Reid" <jeff. reid@aa.com>