This research serves to fill the gaps in the technique of producing traffic sand table models.

Provides a primary mathematics model, ranges test project & date for experiment, where the date is come from the shot of some sand table models.

Study on properties of model sand;

In the river model test of the Luan River reach through Qianxi County,since the prototype bed sand is thicker(with the mid-diameter d50=25 mm)and more extensive in its composition which is not suitable for the design of model sand with the average sedimentation similarity law,a new model sand design is adopted.

In a test of the sand physical model, it is very important to select the model sand with appropriate physical and kinetic characteristics, which is directly related with the similarity of the sediment movement and the change of river bed and with the accuracy of the experimental results.

Conclusions are:(1)series model test is a effective way for test harvest by models whose geometry and current movement are similar and silt movement is not similar;(2)it is too feasible to employ series model test with prototype sand;and(3) only making two models that their scales are greater difference,the needful result can be obtained by test data exte.

Through the research on how to describe the SOC of power system by use of sand pile model, a conception is proposed, that is, the r.

According to the experiments result of sand pile model with fractal features and the fracture mechanics,it was suggested that the SOC phenomena of earthquake is associated with the SOC dynamic process of fractal geometry faults.

We investigate a deterministic,conservative,undirected,and critical height sandpile model with dissipation of an energy at boundaries that can simulate avalanche dynamics.

Sandpile Model(SM) is the typical example of SOC system which has the most physical meani.

The sandpile model offers an alternative route to uncover this self-organizing phenomenon.