Large-scale Shaking Table Test of Seismic Stability of Xiashu Loess Slopes(I):Design of Model Test

Using natural Xiashu loesses and applying the law of similitude after Meymand,a detailed design of a 1g large-scale shaking table model test with a similarity factor of 20 for a model slope with a height of 0.5m,width of 1.05m,and slope angle of 45°was carried out aiming at investigating the seismic stability of Xiashu loess slopes.Firstly,appropriate boundary range of the model slope with a depth of the model slope base,a distance from the model slope toe to the left slope boundary and the one from the model slope crest to the right slope boundary all of 0.5m was identified by means of numerical analysis;Secondly, a rigid model box,which had internal dimensions of 1050 mm by 1500 mm in size and 1100 mm in height according to the determined dimension of the model slope was designed well meeting the requirements of the test and would not cause resonance with the model slope;Finally,tactics of measurements including accelerations and displacements were established,the average critical acceleration of the model slope of 0.561g was determined using the pseudostatic method,a series of loading rules were comprehensively identified in terms of the sequences of the peak ground acceleration(PGA) of 0.1g,0.3g,0.6g and 0.9g,and detailed test procedures were established,which gave a powerful guarantee for the test.