The centrifuge model tests were performed to investigate the ground settlements during tunnel excavation in sandy soil ground. A columnar rubber membrane tube was used to represent a tunnel. Compressed air was supplied to it to create a uniform pressure to support the surrounding soil. During centrifuge running
air pressure was gradually decreased to simulate the initial stress release; i.e.
to simulate the excavating process. Through different combinations of test conditions including soil type
density
water content and tunnel embedment depth; the ground failure patterns and settlements were examined; the normalized P-S relationship were obtained and discussed..