ABSTRACT: A computer program has been developed for analysis of underground openings. In this program the closed form solution method is used considering Hoek & Brown criterion. The program is used to study the' stability of the power cavern of shahid Abbaspour dam project (south of Iran) in terms of deformation and stresses around the opening. Validity of the results obtained by using the above mentioned computer. program has been cross checked by numerical solution as well as by empirical method. The comparison of the predicted results shows a better agreement with the results obtained from numerical solution. it is suggested that the program developed could be used for a rapid assessment of the stability of underground openings in the preliminary stability studies.
RÉSUMÉ: Un programme pour ordinateur a ete developpe pour l'analyse D'ouverture souterrainne. Ce programme utilise la methode "Solution Fermee" considerant les criteres de Hoek & Brown. Le programme est utilise pour l'etude de stabilite en terme de deformation et de forces autour de l'ouverture de la caverne du projet du barrage de la centrale de Shahid Abbaspour (Sud de L' Iran). La validite des resultats obtenues en utilisant Ie programme d'ordinateur mentionne ci-haut ont etes reverifiers par solution numerique. La comparaison des resultats prevues montrent une meilleure entente (correllation) avec les resultats obtenues de la solution numerique. II est suggere que le programme developpe pourrait etre utilise pour une rapide assertion de la stabilite des ouvertures souterraines dans I' etude preliminaire de stabilite.
ZUSAMMENFASSUNG: Ein Computerporgramm wurde zum analysieren der Daten der untertaegigen Raeume entwickelt. In disesem Programm wurde Hoek&Brown Kriterien (closed form solution method) zu Grunde gelegt. Das Programm wurde verwendert, um eme Studie zu stabilitaetsberechnungen der Kaverne (Shahid Abbaspour dam project south of Iran) durch zu fuehren. Hier wurden deformierungen und Spannungen um die hergestellte Hohlraeme in Betracht gezogen. Die Gueltigkeit der Ergebnisse wurden theoretisch, mit hilfe des Computers, auch emplrisch getestet. Der Vergleich zwischen vorausberechnete und erreichte Ergebnisse zeigt, class die nummerische Loesung eine bessere Uebereinstimmung hat. Es ist vorgeschlagen, class das Programm fuer promte Ergebnisse zur Berechnung der Untertagehohlraeum verwendet werden kann
INTRODUCTION Underground openings are being excavated all over the world for various puposes such' as hydroelectric projects, transport, mining activities etc. Presently there are many hydroelectric projects at different stages of study, analysis and construction in Iran. An important component of these' projects are the underground openings which are' often to pass through difficult ground. It is necessary to analyze their stability and understand the state of stresses and deformations around them.
Closed form solutions proposed by Ladanyi (1974) is being considered to develop a computer program for rapid assessment of stability of underground openings. In this paper the suitability of the program has been discussed by analyzing the stability of the power cavern of the extension of Shahid Abbasspour Hydroelectric Power Project in southern part of Iran. The comparison of the results obtained by the above mentioned solution and other available methods are also presented.
CLOSED FORM SOLUTIONS The state of insitu stress field is disturbed by excavation of underground openings. This disturbance results in redistribution of the stresses around the opening. The magnitude of the redistributed stresses applied around the opening with respect to the strength of the surrounding rock would define the rock behaviour.