عنوان مقاله [English]
In this paper measured settlements of Tabriz Urban Railway line 2 (TUR2) are presented. TUR2 with a length of about 22 km will connect eastern part of the city to its western part. The process of excavating TUR2 has begun since 2015, using earth pressure balanced (EPB) TBM with a cutting-wheel diameter of 9.49 m and a steel shield with external diameter of 9.46 m in front and 9.44 m at the tail. For the lining of the tunnels, 350 mm-thick precast concrete segments with a length of 1.5 m are installed just behind the shield. The data have been recorded during construction of the tunnel from west-shaft to station-02 (S02). The distance between west-shaft and s02 which has been investigated here is about 2000 m. In this route, based on conducted studies, the ground mainly consists of sand and gravel (SM) containing predominant portion of fine-grained soil (CL). So in general the ground condition could be assumed to be non-cohesive at this site. The TUR2 tunnel having a mean depth of about 15 m is entirely under water table varying from 15 to 26 m. The data analyzed and discussed throughout this paper has been recorded at 180 green-field surface locations (pins) between west-shaft and s02. Settlement measurements are back-analyzed using Gaussian empirical predictions, both in longitudinal and transversal directions. Also, volume loss has been calculated using final maximum surface settlements. Subsequently, observed and calculated settlement curves has been compared. In addition to settlements, face pressure and tail void grout injection pressure has been recorded during excavation process of TUR2 and are presented in in this paper. Jancsecz and Stainer empirical formula for determination of face pressure was hired to investigate efficiency of the analytical methods in comparison with field data. Then development of settlements during shield passage and probable correlation between volume loss and face pressure was investigated. Observation show that a vast majority of the settlements measured at the ground surface falls in the range of allowable values.