Evaluation of InSAR data for measuring the surface settlement during shield tunnel construction of the North-South Line in Amsterdam

Abstract

This paper investigates the use of InSAR data during shield tunnel construction when short-term settlements occur within a few days. Additionally, the long-term settlement, which occur over several years, in the vicinity of these tunnels are evaluated with inSAR. The North-South Line in Amsterdam is used as a case study for this research. We used the settlement during construction as a-priori information to determine the most likely unwrapping solution for a few selected InSAR points. Then we verified this outcome with the traditional monitoring of the surface levelling points during construction and finally used only the InSAR to evaluate the long-term settlements. We conclude that with prior information InSAR data can be processed correctly and that InSAR can capture the short-term settlement that occur immediately during construction of a shield tunnel. Also, InSAR is a valuable complementary source of information because it provides data outside the area of the levelling points and gives information about settlement patterns prior to and after construction.