Loess Hidden Cave On The Road Hazards And Formation Mechanism Of Study

There are many bad geological engineering matters during the construction and maintenance of Highway. For example, the loess hidden cavity of the special geological engineering problems jeopardizes and destroys the highway and its accessories in the district of loess plateau. However, the research of loess hidden cavity is almost zero from highway engineering. So it is more important practical purpose and theoretical significance to study on the origin mechanism of loess hidden cavity, the characteristic of distribution, the hazard to highway and destructive mechanism.Based on the field investigation and test data, this thesis studies profoundly on the characteristic, the origin mechanism and the characteristic of distribution of loess hidden cavity. At present there are three viewpoints on the origin of loess cavity: mechanical erosion, chemical erosion and multi-factor synthesis effect. But in my opinion, the origin of loess hidden cavity is in result of the interaction of the interior and exterior factors together. The nature of loess (the interior factors) is the decisive function. The current dynamical factor and human engineering activity (the exterior factors) are the subordinate function.From the point of view of highway engineering, the author has summarized the developed characteristic and the law of distribution of loess hidden cavity along highway, analyzed the hazard of the loess hidden cavity to highway, put forward to the hazard models and generalized the hazard characters.Using the numerical method-finite element method has simulated the destructive mechanism of the loess cavity to the foundation of highway and bridge and the relationship of the radius with the critical depth of the loess hidden cavity. By using optimal square approximate method to deal with the computational results, the mathematical model of the radius with the depth has been set up.