An Originally Developed Centrifuge Test Apparatus for Simulating Tunnel Structure Crossings at Arbitrary Active Fault Angles
An Originally Developed Centrifuge Test Apparatus for Simulating Tunnel Structure Crossings at Arbitrary Active Fault Angles
Linear underground infrastructures, such as tunnel structures, inevitably traverse active fault zones, where fault displacements during seismic events can cause severe structural damage and significant economic losses. To investigate the mechanical behaviour of tunnels intersecting active faults, this study introduces an originally developed centrifuge apparatus designed to simulate tunnel-fault interactions. The apparatus features an L-shaped movable frame that represents the hanging wall of the active fault. This frame is driven by both horizontal and vertical jacks, whose displacement rates are manually controlled to replicate reverse or normal fault displacements at arbitrary dip angles. Notably, this setup incorporates a fault-plane guider, which ensures that the fault dip angle is consistently maintained from the bottom to the ground surface, thereby enabling a direct intersection between the tunnel model and the fault plane. The experiments are conducted using the centrifuge modelling system at the Disaster Prevention Research Institute (DPRI), Kyoto University, under a centrifugal acceleration field of 50g. The ground is modelled with Toyoura sand, and the tunnel structure is simulated using an aluminium pipe. A total of 48 strain gauges are installed on the tunnel to capture its structural response, while 16 earth pressure sensors are deployed to monitor soil-tunnel interaction during fault displacement. A series of centrifuge tests were carried out to examine the mechanical responses of tunnels subjected to both reverse and normal fault displacements. The experimental findings provide valuable insights into tunnel behaviour under active fault displacement and offer important references for future design and analysis.
GUANXIONG ZENG; YASUHITO KAMOI; Yasuo Sawamura; Kiyoshi Kishida
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 1: New facilities, new equipment, and measuring techniques
https://doi.org/10.53243/ICPMG2026-75