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One-dimensional injection tests were conducted on sand columns with a height of 134 cm for the penetrability evaluation of microfine cement grouts. Three ordinary cement types were pulverized to obtain microfine cements having nominal maximum grain sizes of 20 and 10 µm, and these cements were used in the present investigation. Suspensions with water to cement (W/C) ratios of 1, 2, and 3, by weight, were injected into 13 clean sands with [d.sub.15] ranging from 0.17 to 2.25 mm and [C.sub.u] ranging from 1.19 to 6.67. Pulverization of the ordinary cements to produce microfine cements extends the range of groutable sands to 'medium-to-fine'. Cement fineness; suspension W/C ratio and apparent viscosity; and sand grain size, gradation, and relative density are very important parameters, as they substantially affect both grout penetration and maximum injection pressure. The penetration length of cement grouts was correlated to parameters pertinent to the suspension, sand, and injection process by performing fuzzy and ordinary linear regression analyses of the injection test results. The resultant fuzzy regression models provided successful penetration length predictions for the majority of the cases analyzed, while the best ordinary regression model exhibited a correlation coefficient not higher than 0.363. Key words: cement grouting, microfine cements, penetrability, fuzzy regression models, grout pressure, filtration. Des essais d'injection en une dimension ont ete realises sur des colonnes de sable de 134 cm de hauteur afin d'evaluer la penetrabilite de coulis de ciment microfins. Trois types de ciment ordinaire ont ete pulverises dans le but d'obtenir des ciments microfins ayant des tailles nominales maximales des grains de 20 a 10 µm, et tous ces ciments ont ete utilises dans la presente etude. Des suspensions avec de l'eau, dont les ratios massiques eau-ciment (W/C) etaient 1, 2 et 3, ont ete injectees dans 13 sables propres avec des [d.sub.15] variant entre 0,17 et 2,25 mm, et des [C.sub.u] variant entre 1,19 et 6,67. La pulverisation des ciments ordinaires pour produire des ciments microfins permet de cimenter des sables consideres comme <>. La finesse du ciment; le ratio W/C et la viscosite apparente de la suspension; et la taille des grains, la gradation et la densite relative de sable sont des parametres tres importants puisqu'ils affectent de facon substantielle autant la penetration du coulis que la pression maximale d'injection. La longueur de penetration du coulis de ciment a ete correlee avec les parametres pertinent pour la suspension, le sable et le processus d'injection, grace a des analyses des resultats des essais d'injection par regression fuzzy et lineaire ordinaire. Les modeles de regression fuzzy obtenus correspondent bien aux predictions de longueur de penetration pour la majorite des cas analyses, tandis que le meilleur modele de regression ordinaire a obtenu un coefficient de correlation pas plus haut que 0,363. [Traduit par la Redaction] Mots-cles: cimentation, ciments microfins, penetrabilite, modeles de regression fuzzy, pression de coulis, filtration., Introduction Improvement of the mechanical properties and behavior of soils by permeation grouting, using either suspensions or chemical solutions, is frequently required to assure the safe construction and operation of [...]