This paper describes the results regarding the measurements and analysis to investigate the characteristics of ground surface settlement when a tunnel is advanced through unconsolidated ground. Rokunohe tunnel is a 3,810m long railway tunnel in Hachinohe - Shin-Aomori section of Tohoku Shinkansen. It is located in almost flat diluvial Tableland (Sambongihara plateau) at elevation of 60m above sea level. The tunnel will pass beneath the public facilities such as roads, railways, water channels for agriculture. Hence, measurements of ground subsidence by using the auto tracking level were adopted to monitor the displacement of the ground resulting from the tunneling. 90 % to the total settlement has been occurred due to the excavation of upper and lower section. Shear deformation appears at the side of tunnel due to the invert excavation. These measurement data shows the needs of auxiliary methods with dewatering method to stabilize the tunnel. The numerical simulation was also applied in order to interpret the measurement results. The validation procedure of effective auxiliary methods based on the investigation are described.