ISSN : 2233-8292
The investigation of the fragmentation of blasted rocks is part icularly important because it is a measure of thet on the efficiency of the loading and crushingoperations. Getting such an information on the large pile of bl asted rock is not an easy operation. This paperpresents the results of case study to evaluate the performance of two types of tunnel blasting: V-cut and burn cut.The digital images of muckpiles were analyzed to produce size d istribution and it was compared with those ofpredictive equations.
The purpose of this study is to improve the problems in Umbrell a Arch Method, such as the oxidation, thedifficulties in installation and cutting of the steel pipe. The applicability of the high strength FRP (Fiber-titute of steel pipe was investigated in this study.The results of this study show that FRP material is better than steel pipe in work performance and the durabilityof material except for its price. From the numerical analysis w ith various types of FRP, it was evaluated that theeloped abroad, and the supporting effect of FRP-grout mixture is similar to that of steel-grout mixture in resu lts of bending strength test.
Four road tunnels, which consists of biotite gneiss and granite gneiss and shows a similar geological conditions,were selected in this study. Laboratory and field tests, the ro ck mass rating for the four tunnels were conducted. Aregression analysis was performed to find out the correlations of test results. It was proposed an equation ofreduction factor which can assess the deformation modulus for b that there was a close correlation between Q and RQD in four tu nnels according to the analysis between RMR andQ, RMR and RQD, Q and RQD and laboratory and field tests.
Recently, as tunnel structure is getting old, many deformations and defects have been occurred. As tunnel hasthe cause of deformation is very difficult. Then, itis necessary to investigate the state of tunnel lining and to e stimate the deformation cause and safety for tunnel.In this study, inspection and diagnosis system for effective ma destructive techniques such as GPR (ground penetrating radar), impact echo test, and infrared thermal techniqueswere applied to tunnel lining inspection. Tunnel lining analysi s system was developed to analyze the stability ofo find the probable causes and indicate themethod for repair and reinforcement for tunnel.
In-situ stress measurement using AE (Acoustic Emission) and DRA (Deformation Rate Analysis) is usually carried outunder uniaxial loading in the laboratory and it consumes delay considered how the lateral stress and delay time influence on t he test results for the in-situ stress determination. As thedelay time increased, the accuracy of estimating the pre-stress decreased. The pre-stress of the specimen loaded onlyE) and 4% (using DRA). And the specimen on which axialpre-stress and the confining pressure were loaded had an error of less than 17% (using AE) and 14% (using DRA). Theresults of AE and DRA for field specimens were very similar wit fracturing method.