Evaluation of building displacement induced by EPB tunneling through GPS-GNSS monitoring system and back analysis technique. Tabriz Subway Twin Tunnels

One of the main aspects of tunneling in urban areas is controlling the amount of settlement that might cause some damage to the structures and infrastructures. In this paper, the novel displacement monitoring system called GPS-GNSS has been applied to monitor the building displacement .One of the most important feature of this approach is that this system provides three dimensional displacement behavior of the building. Besides, in order to fulfill the purpose of accuracy, the amount of settlement happened due to EPB tunneling was calculated by numerical, empirical and analytical methods. In order to achieve this purpose, the back analysis technique was considered. The order in which the geotechnical parameters are optimized depends on the amount of sensitivity function. That is, the parameter of high sensitivity function is optimized first. According to the calculations, the Sensitivity analysis results show that the maximum amount of sensitivity function with the volume loss of more than 11 in respect to the internal friction angle is about 5.6 which is greater than other geotechnical properties. According to the results of back analysis technique, the optimized geotechnical properties were elastic modulus (E=22 MPa), internal friction angle (

Keywords:

settlement , geotechnical properties , Tabriz subway , GPS-GNSS displacement monitoring system , back analysis