Research On Different Wind Erosions Of The Great Wall Earthen Site About Xinhe Dak In Shandan

The different wind erosions of earthen sites surface will accelerate the destruction of site soil, anti weathering protection about earthen site is an important aspect of cultural relics preservation. The purpose of this study is to explore the reasons and mechanisms that have caused surface different wind erosions of New River, thus we can provide certain theoretical basis for the consolidation and strengthening of method and materials.Shandan County is located in the hinterland of Asia, it is far from the sea, near the desert, the vegetation there is poor and it has many bare mountain and hills, it is belongs to continental alpine semi-arid climate. It has many typically features such as low temperature, long sunshine, large difference of temperature, strong solar radiation, little precipitation and concentration, large evaporation, small humidity, short frost free period, many natural disasters etc.Shandan Xinhe dak is a typical represent of earthen site in northwest area, China. This paper carried out a detailed survey, sampling and laboratory test about it, and then to discuss the causes and mechanisms of the different wind erosions, combined with the relevant literatures. Then, ABAQUS finite element thermal analysis method was used to analyze the influence of temperature effect and the stress and strain of three levels of earthen site, whose destination is to explore the temperature effect that have caused the large area weathered earthen site in China northwest. It also analyzed the influencing factors of the different wind erosions base on the laboratory test result. All of them have great significance for the protection and reinforcement of earthen sites.The main contents:(1) Analyze the factors which affect the different wind erosions in Shandan, strong centralized rainfall and the strong evaporation after it will led to the salt moving, temperature gradient and soil salinization. Different soil micro structure and the degrees of the enrichment of salt will provide the material basis for the different wind erosions of earthen sites.(2) Take the climatic conditions in January and July as the representative to analyze the temperature field, stress and strain under different temperature systems, which is use ABAQUS finite element software and the sequentially coupled stress analysis of it.(3) According to the experimental results to analysis the factors of different wind erosions on earthen site, which is basic on the experiment parameters such as particle composition of soil, clay particle and particle content differences, differences of salt accumulation in vertical and horizontal direction, specific gravity, liquid limit and plastic limit etc.