土木工程 建筑外文翻譯 --基于盾構(gòu)法的istanbul地鐵施工引起的地面沉降預(yù)測

1、 中文 中文 5351 字出處： 出處：Environmental Earth Sciences, 2011, 62(2): 357-365外文原文Surface settlement predictions for Istanbul Metro tunnels excavated by EPB-TBMS. G. Ercelebi ? H. Copur ? I. OcakAbstract In this study, short-t

2、erm surface settlements are predicted for twin tunnels, which are to be excavated in the chainage of 0 ? 850 to 0 ? 900 m between the Esenler and Kirazl? stations of the Istanbul Metro line, which is 4 km in length. The

3、total length of the excavation line is 21.2 km between Esenler and Basaksehir. Tunnels are excavated by employing two earth pressure balance (EPB) tunnel boring machines (TBMs) that have twin tubes of 6.5 m diameter and

4、 with 14 m distance from center to center. The TBM in the right tube follows about 100 m behind the other tube. Segmental lining of 1.4 m length is currently employed as the final support. Settlement predictions are perf

5、ormed with finite element method by using Plaxis finite element program. Excavation, ground support and face support steps in FEM analyses are simulated as applied in the field. Predictions are performed for a typical g

6、eological zone, which is considered as critical in terms of surface settlement. Geology in the study area is composed of fill, very stiff clay, dense sand, very dense sand and hard clay, respectively, starting from the s

7、urface. In addition to finite element modeling, the surface settlements are also predicted by using semi- theoretical (semi-empirical) and analytical methods. The results indicate that the FE model predicts well the shor

8、t-term surface settlements for a given volume loss value. The results of semi-theoretical and analytical methods are found to be in good agreement with the FE model. The results of predictions are compared and verified

9、 by field measurements. It is suggested that grouting of the excavation void should be performed as fast as possible after excavation of a section as a precaution against surface settlements during excavation. Face pres

10、sure of the TBMs should be closely monitored and adjusted for different zones.Keywords Surface settlement prediction _ Finite element method _ Analytical method _ Semi-theoretical method _ EPB-TBM tunneling _Istanbul M

11、etroIntroduction Increasing demand on infrastructures increases attention to shallow soft ground tunneling methods in urbanized areas. Many surface and sub-surface structures make underground construction works very de

12、licate due to the influence of ground conditions, the long-term settlements may be considered as very limited. There are mainly three settlement prediction approaches for mechanized tunnel excavations: (1) numerical ana

13、lysis such as finite element method, (2) analytical method and (3) semi-theoretical (semi-empirical) method. Among them, the numerical approaches are the most reliable ones. However, the results of all methods should be

14、 used carefully by an experienced field engineer in designing the stage of an excavation project.In this study, all three prediction methods are employed for a critical zone to predict the short-term maximum surface set

15、tlements above the twin tunnels of the chainage between 0 ? 850 and 0 ? 900 m between Esenler and Kirazl? stations of Istanbul Metro line, which is 4 km in length. Plaxis finite element modeling program is used for nume

16、rical modeling; the method suggested by Loganathan and Poulos (1998) is used for the analytical solution. A few different semi-theoretical models are also used for predictions. The results are compared and validated by f

17、ield measurements.Description of the project, site and construction methodThe first construction phase of Istanbul Metro line was started in 1992 and opened to public in 2000. This line is being extended gradually, as we

18、ll as new lines are being constructed in other locations. One of these metro lines is the twin line between Esenler and Basaksehir, which is 21.2 km. The excavation of this section has been started in May 2006. Currently

19、, around 1,400 m of excavation has already been completed. The region is highly populated including several story buildings, industrial zones and heavy traffic. Alignment and stations of the metro line between Esenler