3.7 Test Procedures

a) After assembly of the model, four hours or eight hours re-consolidation was carried out on the centrifuge at 100g.

b) Subsequently, the zinc chloride solution in the bag was released at a controlled rate to simulate the excavation process. The wall began to move and deflect during the excavation process. During this stage of test, the readings of all the transducers were recorded at regular intervals.

c) In tests involving two slabs, the in-flight installation of the lower strut was carried out in the middle of the excavation process.

d) The long term behaviour of the soil was monitored up to several hours model time after excavation was completed.

e) During the test, a micro camera was employed to capture the soil movement in front of the perspex window throughout the test. After the test, the recorded images of the surface grids throughout the test were loaded onto a computer for image processing.