Influence of Joint in the Phenomena of Solubility of Limestone

Current research, that involves laboratory investigations into the phenomena of solubility, uses circulation equipment that has been developed to study the enlargement of joint aperture. This paper describes the preliminary results of laboratory experiments on ten different length and width of samples, which show that the flow rate through the fissures increases with time as the fissures enlarge. However, when longer samples were used, the flow rate velocity decreased as fissure enlargement decreased. The results from the analysis of the 50 tests performed indicated that the length of sample decreases as the flow rate increases, e.g. the flow rate in sample to length of 100 mm after the period of three months increases from 116.7 to 130.3 ml/s. The flow rate in sample to length of 300 mm increases from 106.1 to 111 ml/s. It was then possible to predict the relationship between enlargement of joint aperture and time, and also Furthermore, to predict the smallest joint aperture which will cause dangerous progressive solution in limestone over 90 day period. The paper shows fissures smaller than about 0.5 mm in aperture are unlikely to be dangerous in most foundation in carbonate rocks.