US Army Corps of Engineers
Studies Amherst's "Sinking Homes"
The Town of Amherst, NY, has over 1,000 homes with reported foundation problems. The US Army Corps of Engineers has completed a study of this.
Click here for the Corps' soil study web page.
A talk on �Expansive and Compressive Soils in Amherst, New York� was
presented by Brad Guay from the US Army Corps of Engineers, Buffalo
District at the April 2005 meeting of
the Buffalo Association of Professional Geologists. The following
abstract is posted on the group's web site at http://www.bapg.org/. Mr. Guay described the
geography, geology, and geotechnical data gathered during USACE�s one year
investigation of foundation related damages to structures Town of Amherst,
NY.
Foundation damages generally result from lateral pressure and/or
settlement. Of primary interest are the lacustrine soils in the lowland
between the Niagara and Onondaga Escarpments. In Amherst,
three-quarters of the homes receiving a foundation repair permit are located on
these lacustrine soils. Of concern to surrounding towns, these soils
extend 35 miles along an east-west trend from Grand Island to the Tonawanda
Indian Reservation.
Geotechnically, the soils are classified as
moderate to highly expansive. Expansive soils undergo volumetric changes as
moisture content varies. Available water, confining pressures, and initial
moisture content also influence potential volume change. In Amherst, a second
causative factor for settlement involves the soft clay stratum beneath the stiff
clay stratum where many residential footings are placed. This soft clay stratum
is susceptible to consolidation by dewatering and surcharge
loading.
Risks associated with building on expansive soils have been well
known for decades in such Western states as Colorado, Texas, and California;
however, experience with expansive soils in the Northeastern United States is
relatively uncommon. Expansive soils in Western states generally have low soil
moisture content, are comprised of highly expansive clay minerals and the houses
typically utilize slab-on-grade construction. Conversely, soils in Amherst are
generally moister, contain non-expansive clays, and houses have full basements.
In both environments, non-uniform changes to the soil moisture content across
the foundation footprint are a primary concern.
The confirmation of both
expansive and compressible soils will have implications for new home
construction in the region, as mandated in the New York State Residential Code.
This study is a prime example of geologic investigations impacting the health
and safety of New York State residents.
Brad Guay is
Hydrologist/Technical Manager at the US Army Corps of Engineers at the Buffalo
District. Brad received his PhD from the University of Arizona (2001) from the
School of renewable Natural Resources, Watershed Resources, Program and
Department of Hydrology and Water Resources, his Masters from SUNY Albany in
Geography, and his Bachelors in Geology from the University of Maine. Brad has
worked for several environmental firms as well as several state government
organizations, notably the NYSDOH and
NYSDEC.
Go to our main "Amherst sinking homes" page
The US Army Corps of Engineers and wetland protection (or lack thereof) were in the news
View excerpts from articles about Amherst's foundation problems
Back to Citizens for a Green North Tonawanda Home Page.
� 2006