贺兰山岩质文物风化特性试验研究

发布时间：2018-04-25 05:15

本文选题：贺兰山岩石 + 吸水特性　；参考：《宁夏大学》2017年硕士论文

【摘要】：贺兰山岩石长期裸露在自然环境中,风化问题严重,岩画濒临消失。为此,本文在其风化现象及水资源调查的基础上,以岩画载体材料-岩石为研究对象,选定岩画景区的6个分区(记为:A、B、C、D、E、F区)为岩样品采集地。首先进行岩样吸水试验,研究岩石质量、自然吸水率和饱和吸水率随浸水时间变化特性,建立岩石吸水率的数值拟合函数,揭示吸水特性在时间序列上的变化规律。然后,模拟光照、温度和风蚀自然风化因素,进行氙灯试验、冻融试验和风洞试验等室内老化试验,分别以240h、480h和50h为一老化周期,进行三个周期的模拟试验,探讨这些因素对岩石质量和吸水率的影响。最后,选取尺寸为1cm×1cm×O.1cm的岩样薄片,从微观视角,采用SEM给出了同一岩样4种不同放大倍数、同一岩画分布区的风化面和新鲜面岩样和6个不同岩画分布区岩样的孔隙特征和胶结结构等微观特性。研究结果表明:岩样质量、自然吸水率和饱和吸水率随浸水时间的延长而增大,二者之间的变化规律满足对数函数,并且岩样风化程度愈大,其吸水率愈大;室内老化试验周期结束后岩样质量减少而吸水率增大,且风化程度愈大,吸水率也愈大,而且A、B区岩样受温度、光照和风蚀这些病害因子影响较大,吸水率变化也最明显,风化程度也最严重,其次为E、F区和C、D区。微观特征研究发现,岩石的风化程度与其吸水特性和微观特征有必然联系,吸水率愈大,孔隙愈多,岩石胶结愈疏松,岩样结构愈不完整,岩画风化程度越大。而且同一岩画区的新鲜面岩样整体性较强,局部为片状或块状,胶结较好,而风化面岩样裂隙发育明显,孔洞较大,结构松散。不同岩画区岩样微观结构越松散,孔隙越大,孔洞越明显,颗粒空间排布越不均匀,岩石完整性破坏越严重,岩画风化程度就越大。本文的研究确定了吸水率和微观特征可以表征岩画风化程度,为贺兰山岩画保护和修复工作提供了一定的理论基础。
[Abstract]:The rock of Helan Mountain is exposed in the natural environment for a long time, the weathering problem is serious, the rock painting is on the verge of disappearing. Therefore, on the basis of its weathering phenomenon and water resources investigation, taking the rock painting carrier material-rock as the research object, this paper selects the six zones of rock painting scenic spot (denoted as the area of the rock painting area) as the collection site of rock samples. Firstly, the water absorption tests of rock samples were carried out to study the variation characteristics of rock mass, natural water absorption and saturated water absorption with immersion time. The numerical fitting function of rock water absorption rate was established to reveal the variation law of water absorption characteristics in time series. Then, simulating the natural weathering factors of light, temperature and wind erosion, the indoor aging tests, such as xenon lamp test, freeze-thaw test and wind tunnel test, were carried out. The effects of these factors on rock quality and water absorption are discussed. Finally, four different magnification times of the same rock sample are given by using SEM from the microscopic point of view by selecting the slice of rock sample with the size of 1cm 脳 1cm 脳 O.1cm. The pore characteristics and cementation structure of weathered and fresh rock samples in the same rock painting distribution area and 6 rock samples in different rock painting distribution areas are discussed. The results show that the mass of rock sample, natural water absorption rate and saturated water absorption rate increase with the prolongation of soaking time, and the law of variation between them satisfies the logarithmic function, and the higher the weathering degree of rock sample is, the greater its water absorption rate is. At the end of the indoor aging test cycle, the quality of rock samples decreases and the water absorption rate increases, and the higher the weathering degree, the greater the water absorption rate. Moreover, the rock samples in AHB area are greatly affected by temperature, illumination and wind erosion, and the variation of water absorption rate is the most obvious. The degree of weathering was also the most serious, followed by EG F and C D region. It is found that the weathering degree of rock is related to its water absorption and microscopic characteristics. The larger the water absorption rate, the more pores, the looser the cementation of rock, the more incomplete the sample structure, and the greater the weathering degree of rock painting. In the same rock painting area, the integrity of the fresh surface rock samples is strong, the parts are flake or block, and the cementation is good, while the cracks of weathered surface rock samples are obviously developed, the pores are large and the structure is loose. The looser the microstructure of rock samples in different rock painting areas, the larger the pores, the more obvious the holes, the more uneven the distribution of grain space, the more serious the damage to the integrity of rock and the greater the weathering degree of rock paintings. The study of this paper determines that the water absorption rate and microscopic characteristics can characterize the weathering degree of rock paintings and provide a theoretical basis for the protection and restoration of rock paintings in Helan Mountain.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：K879.4;P512.1

【参考文献】