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Abstract: This study is about a detailed field and laboratory study concerning Ayazaga-Cayirbasi Water Tunnel Project (Section III) in Istanbul. The excavation and performance parameters of tunnel boring machine (TBM), which is performed in this project, have been investigated. In the first part of the research between February and March 2010, the rock samples were collected from 11 different excavation rings in the tunnel. The performance parameters of the tunnel boring machines are also collected during the excavation of the tunnel. In the second part of the research, Point Load Strength and Shore Hardness tests were carried out at the rock excavation laboratories of the ITU Mining Engineering Department on the rock samples collected during the excavation of the TBM in Ayazaga Tunnel Project. Uniaxial compressive strength was determined by Point Load Strength and Shore Hardness (SH) values from every one of rock samples were obtained by Shore Hardness test. As a result findings were compared with the performance parameters of the TBM values and laboratory results statistically. The predicted performance values are compared with field values and some recommendations are made to tunnel contractors and practicing field engineer. 1 INTRODUCTION The TBM technology โ well known tunnel excavation technique โ have reached a very high level of development and nowadays 10โ50 m/day of advance rates are usual with different types of ground changing from soil to hard rock conditions. Prediction of the excavation performance of TBMs for any geological formation is one of the main concerns in determining the economics of a mechanized mining and/or tunneling operation. Owners, contractors, consultants, design engineers, geotechnical engineers, machine manufacturers and scientists want to estimate approximate performances of mechanical excavators which play an important role in time scheduling of a production program before starting a tunneling job.
- Europe (0.67)
- Asia > Middle East > Turkey > Istanbul Province > Istanbul (0.65)
Rock Mechanics Aspects Related to Cutting Efficiency of Mechanical Excavators, 25 Years of Experience In Istanbul
Bilgin, N. (Istanbul Technical University) | Balci, C. (Istanbul Technical University) | Copur, H. (Istanbul Technical University) | Tumac, D. (Istanbul Technical University) | Avunduk, E. (Istanbul Technical University)
Abstract: The mechanical excavation of utility tunnels in Istanbul started in 1985 with roadheaders and impact hammers. The first TBM application was started for a sewer-age tunnel in 1990. Since then, more than 60 km of tunnels including metro tunnels were excavated with mechanical excavators. A large amount of data was collected continuously by researchers in the Mining Engineering Department of Istanbul Technical University. Rock mechanics and engineering geological aspects of the rock formations affecting the efficiency of the mechanized excavation systems were also care-fully recorded; the performance prediction models were developed and modified continuously for impact hammers, roadheaders and TBMs. This paper will summarize briefly the works done in these respects emphasizing specially on the concept of in situ specific energy when using TBMs. A numerical example showing how to calculate net production rate of a TBM is given based on the model developed in a complex geology. 1 INTRODUCTION The geology of Istanbul is complex and some of the tunnels have been currently excavated in young Cenozoic formations and some of them in complex series of Paleozoic formations. The Paleozoic rock formations are cut frequently by andesite and diabase dykes, fracturing the main rock, decreasing the daily advance rates and increasing the tunneling cost tremendously. Sometimes in EPB (Earth Pressure Balance) TBM applications, excessive ground deformations may cause damages to the surrounding buildings like experienced in Otogar-Esenler metro tunnels which caused an extra cost of 35.6x106 $ to the project. The total length of the tunnels planned to be excavated in Istanbul in near future is 127 km for metro tunnels and 47 km for utility tunnels. Majority of the tunnels will be excavated with tunnel boring machines and the total cost of the operation is estimated to be around 10x109 Euros.
- Geology > Geological Subdiscipline > Geomechanics (0.70)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.31)
- Energy > Oil & Gas > Upstream (0.48)
- Materials > Metals & Mining (0.35)