With recent technological advancements,tunnel boring machines(TBM)have developed and exhibited high performance in large diameters and weak ground conditions.Tunnels are crucial structures that significantly influence...With recent technological advancements,tunnel boring machines(TBM)have developed and exhibited high performance in large diameters and weak ground conditions.Tunnels are crucial structures that significantly influence the timelines of highway and railway projects.Therefore,the construction of tunnels with TBMs becomes a preferred option.In this study,a comparative analysis between TBM and the New Austrian Tunneling Method(NATM)for tunnel construction is performed in the construction of the T1 tunnel with a diameter of 13 m,which is the longest tunnel in the E?me-Salihli section of Ankara-izmir High-Speed Railway Project(Türkiye).The selection of TBM type,measures taken in problematic sections,and application issues of TBM are discussed.The impact of correct description of geological and geotechnical conditions on both selection and performance of TBM is presented.An earth pressure balanced type TBM is chosen for the construction of the T1 tunnel.Because of the additional engineering measures taken before excavation in problematic areas,the tunnel was completed with great success within the initially planned timeframe.From this point of view,this study is an important case and may contribute to worldwide tunneling literature.展开更多
This study is mainly focused on the 3D mechanical cell deformations of 20 × 20 × 60 mm sized softwood specimens under 35 - 40 MPa compression loading at room temperature of 20?C. The moisture content of the ...This study is mainly focused on the 3D mechanical cell deformations of 20 × 20 × 60 mm sized softwood specimens under 35 - 40 MPa compression loading at room temperature of 20?C. The moisture content of the specimens was 6% - 7%. The data of microscopic images were measured and compared in terms of the permanently degenerated individual cell structures each in micro-scale . 3D cell deformations of tissues were observed with a magnification of (×100) - (×1500) and in the range of 3.0 - 5.0 kV voltage under the SEM microscope. The specimens were examined under magnification and photographed before and after the compression loading applied parallel to the grain angles to the wood samples. Specimens were painted with gold liquid (12 × 12 × 12 mm sized specimens) in obtaining the SEM images. Under the SEM, these specimens were photographed and lengths between the cell walls ranged between 15 to 40 micrometers. In this study, relative deformations of pinewood cells were determined statistically considering the percentage permanent deformation under the compression loading. It was performed by using knowledge of structural mechanics, considering the measurement of permanent deformation in honeycomb-pinewood structure material.展开更多
文摘With recent technological advancements,tunnel boring machines(TBM)have developed and exhibited high performance in large diameters and weak ground conditions.Tunnels are crucial structures that significantly influence the timelines of highway and railway projects.Therefore,the construction of tunnels with TBMs becomes a preferred option.In this study,a comparative analysis between TBM and the New Austrian Tunneling Method(NATM)for tunnel construction is performed in the construction of the T1 tunnel with a diameter of 13 m,which is the longest tunnel in the E?me-Salihli section of Ankara-izmir High-Speed Railway Project(Türkiye).The selection of TBM type,measures taken in problematic sections,and application issues of TBM are discussed.The impact of correct description of geological and geotechnical conditions on both selection and performance of TBM is presented.An earth pressure balanced type TBM is chosen for the construction of the T1 tunnel.Because of the additional engineering measures taken before excavation in problematic areas,the tunnel was completed with great success within the initially planned timeframe.From this point of view,this study is an important case and may contribute to worldwide tunneling literature.
基金supported by Gazi University Scientific Research Projects Department with Grant Ref No:6/2006-07.
文摘This study is mainly focused on the 3D mechanical cell deformations of 20 × 20 × 60 mm sized softwood specimens under 35 - 40 MPa compression loading at room temperature of 20?C. The moisture content of the specimens was 6% - 7%. The data of microscopic images were measured and compared in terms of the permanently degenerated individual cell structures each in micro-scale . 3D cell deformations of tissues were observed with a magnification of (×100) - (×1500) and in the range of 3.0 - 5.0 kV voltage under the SEM microscope. The specimens were examined under magnification and photographed before and after the compression loading applied parallel to the grain angles to the wood samples. Specimens were painted with gold liquid (12 × 12 × 12 mm sized specimens) in obtaining the SEM images. Under the SEM, these specimens were photographed and lengths between the cell walls ranged between 15 to 40 micrometers. In this study, relative deformations of pinewood cells were determined statistically considering the percentage permanent deformation under the compression loading. It was performed by using knowledge of structural mechanics, considering the measurement of permanent deformation in honeycomb-pinewood structure material.
