Fu Hongyuan

Experimental Study on Dynamic Deformation Characteristics of Weathered Conglomerate under Cyclic Loading

The durability and safety of the subway tunnel structure is contingent on the substrate deformation under the subway operating load, which is a low frequency, long-term repetitive dynamic load. Using dynamic tri-axial cyclic loading test, the dynamic strain for weathered conglomerate under low-frequency cyclic loading was studied, while the influence of factors such as dynamic stress amplitude, static deviator stress, confining pressure impaction and loading frequency on dynamic strain of weathered conglomerate were analyzed. The results showed that, the deformation development of weathered conglomerate was basically stable convergence curves under low frequency cyclic loading, and the deformation could be divided into early stage (characterized by an increase in deformation) and stable stage with accumulative deformation in the early stage accounted for more than 90% of the total deformation. For the case of exceeding the critical stress amplitude, strain development of weathered conglomerate was quadratic curve type, and reached failure state. The results of dynamic test could provide useful reference to the dynamic design of subway tunnel.

The Game Analysis on Adverse Selection in the Process of Expressway

In order to explore the generation mechanism of adverse selection risk in the process of expressway concession right transfer, this paper establishes information screening model from the angle of main body behavior, using the game theory and the principles of information economics. Through the analysis on the model, it puts forward to some suggestion about risk prevention, namely: an improved contract form, it is divided into several stages, then it adopts punitive measures after the first stage to realize separating equilibrium. Thus, the risk of adverse selection is solved.