SWELLING EXPERIMENTS ON MUDROCKS
This paper studies swelling of highly-consolidated mudrocks by theoretical considerations and laboratory experiments. A key assumption that saturated and uncemented clays behave as heavily dense colloid without direct contacts between solid particles leads to an important conclusion that the swelling pressure acting in adsorbed interparticle water-films is equivalent to the effective stress1. In this paper, this so-called clay-colloid concept is validated by various swelling experiments on two mudrocks, the Callovo-Oxfordian argillite in France and the Opalinus clay in Switzerland. In the tests, water adsorption-desorption, swelling pressure and strain were measured on the samples at various suction-and load-controlled conditions. The results suggest that a) the mudrocks can take up great amounts of water from the humid environment, much more than the water content in the natural and saturated state; b) the swelling pressure increases with water uptake to high levels of the overburden stresses at the sampling depths of 230 m to 500 m, indicating that the adsorbed water-films are capable of carrying the lithostatic stress; and c) the large amount of the water uptake causes a significant expansion of the mudrocks even under the lithostatic stresses.
clay mudrock adsorption swelling pressure ezpansion suction stress analysis ezperiment
C.L. Zhang K. Wieczorek M.L. Xie
Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS), P.O. Box, 38122 Braunschweig, Germany
国际会议
上海
英文
112-120
2009-08-24（万方平台首次上网日期，不代表论文的发表时间）