Thanks to the few folks who provided some response to my posting a
couple of weeks ago on "BLASTING DAMAGE TO MY HOUSE". But I still
need documentation sources or references to help me proceed with this
thorny problem. With millions of homeowners in our great land, I am
certain others with common house construction have experienced a
situation such as ours. Surely we are not alone!

More details of our situation are in this message. I WILL TRULY
APPRECIATE any response or guidance specific to our problem.

Several blasting sessions were done in our neighborhood at a
construction site, about 1/4 mile from my house. The measured level
of blasting recorded by a small engineering group shows only lower
levels at their few monitored locations, which did not include our
property.

My basement is a 2-car garage and large finished room. When first
discovered and shown in photos taken by my insurance company's
engineer, there were several slightly noticeable, hairline cracks
"stair stepping" down my foundation. . The stair-step cracks start
at the top of the foundation, and extend several feet down to
approximate outside ground level. Previous to discovering the cracks
our foundation and basement had always been very tight and dry. My
wife and I saw no cracks during 11 years of ownership, including
accompanying a pest control person in annual foundation inspections,
and my daily parking about 2 feet from the foundation . I have
documented the foundation cracks with many good photos and have a
copy of the insurance engineer's photos.

In both bathrooms the tile was previously intact, but both now have
long horizontal cracks through the tile. Also, we discovered several
interior door frame mouldings throughout the house that separated
slightly from the wall. There were no separations before the
blasting. During the blasting period my wife found picture frames
throughout the house hanging un level, but none fell off the wall.

Initially by phone, several repair contractors and people with basic
knowledge of blasting all confirmed with me that we had no previous
foundation cracking, and asked if the cracks were horizontal or
"STAIR-STEP" in appearance. All said stair-step cracking is a
characteristic of blasting. And that horizontal-lateral cracking is
characteristic of outside earth pressure on a concrete block
foundations. A structural engineer who inspected for us discovered the
hairline cracks in the bathroom tile, and said that is another
characteristic of blasting damage. He said "you have plenty of things
to work with" related to the blasting.

My homeowners insurance company continues to maintain that because
measurements of the blasting show only lower levels it didn't cause
any of the cracking. Yet we had none of this before!

I've had to file my one and only law suit (in 60 odd years of life)
against my home owner insurer and the blasting company. But my lawyer
has not been able to find any DOCUMENTATION which supports the common
knowledge that shock waves from blasting cause "stair-step" type
cracking in concrete block foundations. My lawyer in the small firm
has no experience in blasting related cases but he and the owner have
a reputation of being very honest, meticulous, tenacious, and
successful attorneys. They came very highly recommended and have
definitely lived up their reputation in working with me.

This is why I am searching via the Usenet for some documentation
showing that LOW LEVEL blasting or FRINGE-AREA disturbances of higher
level blasting are known to have caused the types of cracking we've
experienced. Documentation such as engineering studies, court trial
records, or out-of-court settlements or repairs by blasting companies
would be very helpful.

Specifically, I need to locate any documentation which discusses the
following:

(1) Stair-step type cracking in concrete block foundations being
characteristic of blasting.

(2) Typical damage appearance from low-level or fringe-area blasting
in above- ground
below-ground, and sloping above-below ground, previously intact
foundations.
Appearance initially and in the months and years that follow is very
important.

(3) Typical, initial blasting damage appearance in bathroom tile.

(4) Good practice requirements for geo-technical surveys before
blasting.

(5) Good practice requirements for placement and density of
seismometers in residential environments.

(6) Higher damage probability in certain types of soil, faults and
rock formations, etc, etc.

(7) Higher damage probability during rainy periods.

(8) Other documentation which can help one understand and
realistically deal with this situation.

As a layman I have come to believe that shaking of house structures,
even due to lower-level or fringe-area blasting can slightly damage
and weaken foundations and other masonry, especially in older
structures. Then over the next year or two, weight and forces in
mother nature expose these flaws as major problems. And I think
insurance and blasting companies work hard, incurring very
considerable expense, to keep the issue from becoming public knowledge
and well documented. I don't expect I can slay this sleeping giant
but I certainly hope a few fellow citizens out there in "Net Land"
will give a some guidance to help me clear a little of the muddy
water, and get some justice.

Also, are there any true investigative reporters out there? This is
an IMPORTANT ISSUE which ultimately costs american home owners major
bucks.