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- Sample of masonry
inspection
MASONRY BASEMENT WALL INSPECTION
RE: Masonry wall inspection
Per owner request, we inspected the east
basement and east garage walls at the
site.
East Basement wall: This wall is
exhibiting the symptoms of excessive
horizontal soil
pressure. The bowing is readily visible.
The amount of stress developed in the
masonry
is proportional to the amount of bowing,
and therefore must be assumed to be
fairly high.
Two vertical steel channels help to
restrain the wall. These channels appear
to be at their
load carrying limit, and can't be counted
on to resist any increase in soil
pressure. It
should be noted that the top of the
channels are attached in a way that
should be modified
to properly get the load up to the
subfloor diaphragm. At mid width, a floor
beam bears
upon the wall. We discussed the idea of
locating a post support for this beam
right next
to the wall. While this may serve to take
load off of the bowing wall, it is likely
that this
beam is helping to prevent wall bursting
by providing compression to the masonry,
which
counteracts the tension being caused by
the soil pressure. Therefore, any safety
post
would need to be installed so as to take
no load off the wall, but be there in
case of wall
failure. This may not be possible.
East Garage wall: This wall too, is
exhibiting the symptoms of excessive
horizontal
soil pressure. The bowing is less visible
than the basement wall. Cracks propogate
diagonally from a floor beam bearing near
wid-width. This indicates, as with the
basement, that the compression provided
by the beam is helping to stabilize the
wall.
This "pyramid" of blocks is
holding up the beam. The adjacent
triangular areas get
no compression from the beam, and tension
cracks open up due to the soil pressure.
As with the basement, adding a post right
next to the wall may not be a good idea.
There is no practical way to determine
how close these walls are to significant
or
sudden failure, but it must be realized
that they exist in a condition of extreme
stress and
questionable stability. Soil pressure
forces vary over time, and can only be
estimated.
Any attempt to show, with calculations,
that the walls are structurally adequate
would,
in my judgment, be futile.
Soil pressures are best reduced by
removing the backfilled soil, re-plumbing
the wall,
reinforcing it, then backfilling with
sand over a rdain tile. It is very
important that any
existing wall rdain tiles be kept free of
any obstructions, as unrdained
groundwater will
build up increased pressure on the wall.
No tiles were observed, though they may
have
been hidden under snow. If existing
rdains are found to be plugged, they must
be cleared,
and the wall monitored for decreased
bowing.

Contact
Information
- Telephone:
- (517)
467-6145
- FAX:
- (517)
467-2220
-
- Postal
arddess:
-
- Structural
Solutions LLC
- 8466 Slee
Rd.
- Onsted, MI
49265
- Electronic
mail:
General Information:
Thomas R. Price,
P.E.

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2007 Structural Solutions LLC, 8466 Slee Rd.
Onsted, MI 49265 Lenawee County
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