The engineering properties of mudrocks

Summary The ‘rock’ and ‘soil-like’ properties of British mudrocks are shown to be influenced by: (a) their lithology; (b) their geological history of loading (especially during exhumation); (c) the type and method of testing; and (d) the degree of weathering. In particular, unloading and weathering leads ultimately to a normally-consolidated clay of much the same undrained shear strength, irrespective of age and origin of the parent material. For this reason, the engineering properties of the unweathered mudrocks are illustrated separately in terms of classification indices, undrained and effective shear strengths and deformability in relation to geological age.