贺兰口岩画风化病害机理

Study on the weathering mechanism of Helankou rock art

贺兰山岩画在世界岩画中占有重要的地位,由于自然环境因素的长期作用,贺兰山岩画遭受到了严重的破坏,若不尽快采取有效措施,这些珍贵的历史文物将不复存在。但是,截至目前关于贺兰山岩画风化机理的研究甚少,从而严重制约了对其风化机理准确地、有效地科学认识。为此,以贺兰口岩画为研究对象,在风化现状调查的基础上,对其保存环境的温度、湿度、大风及沙尘天气等数据进行统计分析,利用X射线衍射仪、扫描电子显微镜等测试手段,并结合冻融实验和风洞试验进行风化病害机理研究。研究发现,贺兰口岩画以长石杂砂岩为主,引起其风化的因素有温度、湿度、风沙等。其中,温度变化和风沙剥蚀为主要病害因素。该研究有望为全面了解岩画风化机理以及其后续保护工作的实施提供理论基础。

The weathering of rock arts located in the Helan Mountains has been severe damaged and shows characteristic patterns of crack propagation and exfoliation.These precious historical relics will disappear soon without effective protection.In this paper,the data on humidity,wind and temperature have been analyzed statistically on the basis of surveys of current status of Helankou rock paintings.Subsequently,X-ray diffraction（ XRD） and scanning electron microscope（ SEM） analyses were undertaken on rock samples to investigate their components and microstructure.In addition,freeze-thaw and wind tunnel experiments were done to study the weathering mechanism.The results show that the rock is composed mainly of feldspar greywacke,and that the key weathering factors are humidity,temperature,wind and sand erosion.The research would provide a theoretical basis for the understanding of the mechanism of rock weathering and actions to be taken for their protection.