Do you Texas engineers observe any use of mixing lime with the clay or even pumping
a slurry of lime into fissures? Peck mentions this in his textbook. Sounds like it would be expensive for
single family dwellings. What about
using a geotextile to wrap an influence area beneath
the foundations to keep a constant moisture content? How deep is that geological formation
Glenn C. Otto, P.E.
LIBERTY ENGINEERING, P.C.
From: Davis Parsons
Sent: Monday, November 18, 2002
Subject: Re: Have you heard of
watering your foundation?
asked this question by my brother who is building a house in the Dallas area. I
am a structural engineer in New York state and my response was- What? Why? I
have not heard of this practice and neither has anyone I work with. The people
he has spoken to (who are not engineers) saythat if you don't water the
concrete it somehow loses strength and cracks. The only thing I can figure is
that the clay soil there has not been preconsolidated by glaciers as it has
here and the moisture is kept up to prevent consolidation and settlement of the
house. Am I on the right track?Bruce C. Trobridge PE
Building Structural Engineer
NYS - Office
of General Services
North Texas has a large area of expansive clays with tremendous shrink-swell
potential. Geotechnical reports commonly give PVR (Potential Vertical
rise) estimates for our soils. The Woodbine formation which runs from just on
the east side of Fort Worth in an ESE direction can have a PVR of up to 8
inches. Due to our expansive soils, it is common practice to "water your
foundation" on a weekly practice to prevent the soils from drying out.
Soaker hoses should be laid along the foundation and used every two weeks
during a dry spell. The intent is to ensure a constant moisture condition
around the perimeter of the foundation to reduce the shrink-swell potential.
Davis G. Parsons II, PE RA AEI
a practical architectural engineer
in Fort Worth, Texas