The effects of using face bolt at shallow urban tunnels on the tunnel stability: Bornova metro case [Si{dotless}g şehir tünellerinde ayna çivisi kullani{dotless}mi{dotless}ni{dotless}n tünel durayli{dotless}li{dotless}gi{dotless}na etkisi: Bornova metro örnegi]

Boren;DEMiR Export;et al;metso Expect results;Outotec;TMMOB Maden Muhendisleri Odasi23rd International Mining Congress and Exhibition of Turkey, IMCET 2013 -- 16 April 2013 through 19 April 2013 -- Antalya -- 105453Settlements during the driving of the tunnel is an important part of excavated tunneling process until the establishment of support and tunnels pre convergences due to the movement of the face into the tunnel. Therefore possible to reduce the amount of ground face to increase the stability of the tunnel. To this end, the face into the fiber columns, jet grout columns, face bolt, etc., can be performed. In this study, the tunnel excavation stage of permanent support with other support systems studied the effect of the face and applying face bolting case studies were evaluated with the use of the stability of the tunnel. The results clearly demonstrated that the effect of the face bolts in the direction that prevents on the ground settlements

Numerical modeling for the umbrella arch application at the shaft and tunnel intersection

ISRM International Symposium on Rock Mechanics 2009, SINOROCK 2009 -- 19 May 2009 through 22 May 2009 -- -- 139056In order to finish urban shallow tunnels (driven by NATM) projects as scheduled shafts should be sunk at certain intervals to form new excavation faces. Entering the tunnel from nearby shafts in addition to the tunnel axis to create new excavation faces is time consuming and costly. For this reason, to form new excavation faces directly from the shafts sunk in tunnel axis seems more economical. However, the greatest problem in such a study appears to be the stability. The stress accumulations at tunnel-shaft intersection areas contain hazard from the aspect of stability. Although it is not likely to face serious stability problems in strong rocks, this situation is potentially prone to reaching to dangerous levels especially in weak rocks. In this study, the stability at the shafts sunk in the tunnel axis and the intersection points of Goztepe station as part of the 2nd stage of Izmir Metro, was analyzed by numerical modeling. The accuracy of the numerical modeling results was later verified comparing with the results of in-situ surveys and measurements. During the study, shaft-tunnel intersection areas have been consolidated by umbrella arch method. The main reason for this strengthening was the obvious difference in the sizes of the shaft and the tunnel i.e., shaft crossectional area was smaller than that of tunnel. Therefore, stability of tunnel-shaft intersection area was designed accounting that the whole load of the shaft was to be carried by the tunnel support and the ground itself. © ISRM International Symposium on Rock Mechanics, SINOROCK 2009

Chemical injection to prevent building damage induced by ground water drainage from shallow tunnels

Progressive developments in the application of chemical injection have been acquired through out the centuries, starting from the ancient Romans. The method of silica based injection has been employed for a long time and has replaced the polyurethane injection method since the 1970s as a remedy in difficult ground conditions including fractured rock. Currently, various applications of chemical injections are available in civil and mining engineering, including ground stabilization, support anchoring, strata sealing, reduction and diversion of ground water flow and water ingress and creation of a load-bearing ring in tunneling. Drainage of the ground water in the overburden during tunneling will result in an increase in ground settlement by the evacuation of water and closure of the pores in overburden. In this research, the ground water level was decreased to 3 m from the original level and the ground settlement was recorded to reach 25 mm, while the inner tunnel vertical convergence was 6.5 mm after the drainage of 3.5 l/s ground water from the tunnel. Subsequent field measurements and observations indicated that the ground water drainage in the tunnel was reduced to 0-0.5 l/s and the surface settlements were stopped after the chemical injection. © 2009 Elsevier Ltd. All rights reserved.This study was conducted under the Scientific Project Number 2005384 of Dokuz Eylul University of Scientific Research and the protocol made with Bozoglu Group Construction Inc. The authors would thank Metin Eris and Levent Nuray from STFA (consulting firm), Mustafa Attaroglu and Yalçın Yilmaz from Bozoglu Group for their collaboration. At the same time, the author offers his gratitude to the employees of Doga Technique Inc. for their scientific study during the chemical injection

Prediction of the performance of impact hammer by adaptive neuro-fuzzy inference system modelling

Impact type excavators are widely used for excavations, performed in weak-laminated-foliated-anisotropic rocks. Therefore the prediction of the performance of impact hammer is very important in many mining and civil engineering projects.This paper describes the construction of adaptive neuro-fuzzy inference system model for predicting the performance of impact hammer type excavator by considering rock and excavating machine properties such as block punch strength index, geological strength index system and impact hammer power. Extensive field and laboratory studies were conducted in the tunnel construction route of the second stage of Izmir Metro Project, which excavated in laminated-foliated flysch rocks. The results of the constructed adaptive neuro-fuzzy inference system and traditional multiple regression models were compared. Although the prediction performance of traditional multiple regression model is high, it is seen that adaptive neuro-fuzzy inference model exhibits better prediction performance according to statistical performance indicators. By means of the developed model, the performance of impact type excavators can be predicted in terms of net excavation based on the selected rock and machine properties. © 2010 Elsevier Ltd.2005384Some part of the this study was conducted under the scientific project numbered 108M151 of TUBITAK (The Scientific and Technological Research Council of Turkey) and 2005384 of Dokuz Eylul University of Scientific Research Bureau, and the protocol made with Bozoğlu Construction Inc. The authors would like to thanks Izmir Greater Municipality, Metin ERIS and Levent NURAY from STFA (consulting firm), Mustafa ATTAROGLU and Yalçın YILMAZ from BOZOGLU GROUP Construction Inc. for their collaboration