The static modulus of deformation of rock mass is undoubtedly the geomechanical parameter that best represents the mechanical behavior of rock mass. In particular, when it comes to underground excavations, this modulus becomes indispensable - whatever the type of design approach to be developed. The modulus of deformation of the rock mass should be determined in situ carrying out special tests, which normally imply considerable costs and operational difficulties. In the following note, case histories are illustrated in which, contrariwise, the static modulus of elasticity of the rock mass was indirectly determined by using different empirical methods known in literature. The paper also includes an original equation based on the static modulus of elasticity of the rock material, on the dynamic modulus of the rock material and on the dynamic modulus of the rock mass.
Der statische Verformungsmodul von Gesteinsmassen ist zweifellos der geomechanische Parameter, der auf beste Weise das mechanische Verhalten von Gesteinsmassen wiedergibt. Dieser Modul wird unentbehrlich besonders wenn es sich um groβe unterirdische Grabungen handelt, unabhangig von der zu entwickelden Projektplanung. Der Verformungsmodul von Gesteinmassen muf an art mittels entsprechender Proben festgelegt werden, welcher normalerweise betrachtliche Kosten und Schwierigkeiten im Einsatz mit sich f_hrt. In der folgenden Notizen werden einige Falle beschrieben bei denen hingegen der statische Elastizitatsmodul der Gesteinsmasse indirekt mittels empirische Methoden festgelegt wurde, die litherarisch bekannt waren. Die Notiz enthalt auch eine originelle Gleichung, welche auf dem statischen Elastizitatsmodul des Gesteinmaterials, auf dem dynamischen Modul des Gesteinmaterials und des dynamischen Modul der Gesteinsmasse beruht.
Le module de deformation statique de la masse rocheuse est sans aucune doute le paramètre geomecanique qui represente le mieux le comportement mecanique de la masse rocheuse. En particulier, ayant trait à de grandes fouilles souterraines, ce module devient indispensable, n'importe quel type d'approche soit adopte pour le projet à developper. Le module de deformation de la masse rocheuse doit être determine par des essais speciaux executes in situ, ce qui implique normalement des coûts considerables et de remarquables difficultes operationnelles. Dans la note suivante, des cas reels sont illustres où, au contraire, le module d'elasticite statique de la masse rocheuse fut determine indirectement en utilisant de differentes methodes empiriques connues dans la litterature. La note inclut egalement une equation originelle basee sur le module d'elasticite statique du materiau rocheux, sur le module dynamique du materiau rocheux et sur le module dynamique de la masse rocheuse.
The static modulus of deformation of rock mass is undoubtedly the geomechanical parameter that best represents the mechanical behavior of rock mass. In particular, when it comes to underground excavations, this modulus becomes indispensable - whatever the type of design approach to be developed. Whatever the procedure opted for and used, the direct measurement of the static modulus of deformation is time - consuming and implies notable costs and operational difficulties. Because of such difficulties, especially in the preliminary stages of a design, the value of the modulus of deformation is often simply assessed by the engineering geologist in charge either on the basis of his personal experience, or else based on literature data. Given the importance of having the value of the modulus of deformation available and, at the same time, the operational and economic difficulties mentioned above, many researchers were led to consider several cost-effective and not too time-consuming indirect procedures that can provide a sufficiently accurate information on the modulus of deformation (Bieniawski 1978, Bowles 1984, Deere et al. 1967, Serafim and Pereira 1983, Grujic 1974, Kujundzic and Grujic 1966, Yoshinaka et al. 1983, Barioli 1966, Drozd and Louma 1966, Murphy and Holt 1966).