The high gravity geotechnical centrifuge facility is mainly consists of the ZJU-400 centrifuge and the 20gton centrifuge shaking table. The centrifuge machine will produce hundreds times of the earth gravity acceleration (g) through high speed rotation, thus gravity field in deep layers can be reproduced in the centrifuge model on the scale of 1-2 meters. For example, if g increases 1000 times, the model dimension h decreases 1000 times, and the fluid velocity also increases 1000 times, migration time decreases 1000,000 times only 53 minute is needed in the centrifuge tests to simulate 100 year migration process in the prototype.
Based on the similarity principle, the centrifuge facility is used in physical model tests under ng condition for geotechnical engineering to investigate the physical behavior and failure mode. The research direction includes foundation engineering, dam project, earthquake engineering, geoenvironmental engineering, underground space engineering, deep-sea engineering and so on.
The technical specifications of the ZJU-400 centrifuge is as following: (1) Maximum capacity is 400 gton;(3)Maximum acceleration is 150g; (3) Effective volume of baskets is 1.5m×1.2m×1.5m; (4) Effective arm radius is 4.5m;(5)volume of containers is 1.2m1m1m. And the technical specifications of the 20gton centrifuge shaking table is as following: (1)Maximum acceleration is 40g;(2) Maximum velocity is 188 cm/s (30 Hz);(3) Maximum displacement is 10 mm(<20 Hz);(4) Effective frequency range is 10 Hz-200 Hz;(5)Maximum load weight is 500 kg.
This system isused in physical model tests under ngconditionfor foundation, slope, tunnel, and pile engineering to investigate the physical behavior and failure mode. The system consists of the steel structurebox, the water-level control system, the loading system and the monitoring system.The box is 15 m long6 m high and 5 m wide.The system has following function: (1) Construction and loading of pile foundation; (2) Traffic cyclic loading; (3) Slope stabilityunder rapiddrawdown of water level; (4) Excavation of deep foundation pit; (5) Soft foundation treatment; (6)Marine geotechnicalengineering.
