Rock mass characterization and classification are significant parts in any field geological investigation involvingrock engineering problems. This process usually involves collection and recording of a sizable amount of data. Moderntechnological advances have resulted into useful electronic tools such as personal digital assistants (PDAs) which are excellent ingathering information which can be easily transported. Today?s PDAs have enough computing power and accessories to competewith portable computers of a few years ago. The present paper presents a comparative review of two of the most frequently usedrock mass classification systems, the Q system and the Geomechanics Classification and an electronic field book tool based onPDA to aid in rock mass characterization and classification for rock engineering. The main aim is to assist the field engineer bytaking out most associated paperwork during characterization and subsequent rock mass classification, by providing a useful tool.The PDA data acquisition tool can be used with either of the two systems, Q or RMR (and SMR) and provide a user friendlyenvironment for quick and safe data recording. In addition technological features such as digital photographs or GPS basedcoordinate acquisition can be readily embedded in the tool if required as an option for onsite investigations.
Two of the most widely used rock massclassification systems today are the Rock MassQuality Index (Q System) by Barton, Lien andLunde  and the Geomechanics Classification(RMR) by Bieniawski [2,3,4]. Both systemsreceived various developments and enhancementsduring years, with the latest being in 1989 for theRMR and in 1993 for the Q system. Both systemswere derived from case histories, by careful andthorough examination of parameters contributingmost to the stability of a rock engineering work,mainly tunnels or mines. Differences and the way ofassociation between the two systems have long beenthe topic of research by many engineers around theworld and only some aspects of these differenceswill be subsequently presented. However, it isimportant to recognize that not all systems can treatthe same problem, nor quantify rock quality in thesame way. This is the reason for the wealth ofsystems presented so far.
An initial observation can be made with respectto RMR which is shown to have received variouschanges and modifications by researchers to handledifferent problems more efficiently, in mining,tunneling, slopes and foundations while the Qsystem has received fewer modifications mainly forunderground design applications. When bothsystems are applied wisely, and with full knowledgeof their limitations, they become excellent tools inthe hands of the engineers.
Common in all the above is the ability toefficiently and quickly record field informationwhen applying these methods onsite. Taking theexample of a tunnel excavation in rock, all thepreliminary design work or modification during theexcavation is based on the differentiation of therock mass quality in different sectors. When thisprocess involves the use of the observationalmethod then continuous data updating is paramount.The present paper presents an electronic tool whichaims in making easier and more efficient insitugeologic data acquisition. The tool aims inminimizing paper based rock mass quality datacollection, based on the above two establishedsystems, with the ability to process the obtaineddata statistically in order to conclude a generalqualitative description for a location, based onindependent observations of the governingparameters.