Study On The Influence Of Environmental Factors On Danfeng Gate Site Of Daming Palace

Danfeng Gate Site is an important historical and cultural heritage of our country, which is also the first batch of display relics of the Darning Palace National Heritage Park, with outstanding historical, artistic and scientific value, and it is non-renewable and irreplaceable. Although the Danfeng Gate Site was covered with protective building, being in relatively confined and stable indoor environment, with the passage of time the soil site was constantly subjected to erosion and damage of various environmental factors, resulting in various diseases and severe weathering. Therefore, in order to protect the Danfeng Gate Site reasonably and effectively, and prevent or delay the erosion of various environmental factors on the site of the body, having to analyze the influence of these environmental factors, like temperature, humidity, on the Danfeng Gate Site indoor environment. In finally,having clear understanding of the weathering mechanism of the soil site,and adopting effective protection means,which is also instructive for the construction of similar site museum in China.By field disease investigation and analysis of influencing factors of the Danfeng Gate Site, the result showed that the main diseases were crisp alkali dig pitting and crevice.In addition, the major environmental factors, which affected formation and development of site disease, were temperature, humidity and water and salt migration.By way of continuous monitoring on air environment, temperature and humidity parameters of the site of the Danfeng Gate Site. The results revealed that the temperature of environment reached the minimum at8o’clock, and reached the maximum at20o’clock, and the result of humidity was opponent. Furthermore, temperature gap of environment was21.44℃, and humidity gap was42.46%during monitoring, which bringed to light that the fluctuation range of air temperature and humidity was large. Moreover, through comprehensive analysis of on-site monitoring and indoor simulation experiment, the results indicated that the degree of change and mean level of site temperature dropped more and more with the depth of site increased. The change of site temperature was later than air temperature. The lag time was from2to8hours within Ocm～25cm. In addition, within0cm～5cm of soil surface the temperature was the most dramatic change.According to the study of indoor simulation experiment, the result declared that the temperature significantly influenced the weathering and water and salt transport of soil site. In the repeated effect of temperature, the soil samples’ weight reduced, unconfined compressive strength gradually decreased, particle gap turned into bigger, and the disintegration speed showed an increased trend of the overall rate. Moreover, it was conducive to the preservation of sites in the environment of10～30℃. With the increase of environment temperature, the moisture content and conductivity changed greatly, and the degree of influence on water and salt transport was most significant in the condition of70℃.Ultimately, the research outcome signified that drying and wetting cycle, based on effect of capillary water and the change of humidity, significantly influenced the weathering and water and salt transport of soil sites.In the repeated effect of drying and wetting cycle, the soil samples’ fissures continuously developed and interconnected, disintegration speed showed a increased trend of the overall rate, particle size becomes smaller and gap turns into bigger, unconfined compressive strength gradually decrease, and the salt of soil crystallized within1～3cm of soil surface. Additionally, with the reduction of environment humidity, the moisture content and conductivity changed greatly, and the degree of influence on water and salt transport was particularly significant in the condition of10%. Therefore, the environment humidity was harmful to the preservation of soil sites in the dry environment below10%, and the environment humidity had small effect on water and salt transport of soil sites in the environment above40%.