ABSTRACT
It is noted that many of the larger older dams in the United Kingdom were built with a puddle cloy core. This does not refer to a particular type of clay, but refers to the way the clay was placed at a high moisture content by puddling. The clay may be asdug local material, and in other cases materials were mixed, sometimes including sand and gravel. Puddling is a process that destroys the natural structure of the clay be remoulding and working in extra water to form a wet clay fill with an undrained shear strength as low as 10 kPA on placement. The various “standard design features”, and development of these features with time is described in Johnston et al (1999) andMoffat (2002).
