Environmental Assessment And Modification Optimization Of Clay Sculpture Preservation In High Humidity Area Of South China

Painted clay sculptures are widely distributed in China and can be divided into grottoes and temples according to different preservation environments.Temple clay sculptures are directly affected by frequent fluctuations of the external environment because they are preserved in open temples and temples.Among the environmental factors that affect the deterioration of clay,temperature and humidity are the most important.The fluctuation of temperature will cause thermal expansion of material surface and produce temperature stress.The intrusion of water will cause the salt inside the clay sculptures to dissolve and migrate to the surface to produce salt damage,which will further trigger the peeling and efflorescence.Meanwhile,the fluctuation of humidity will cause evaporation on the surface of the clay sculptures.Under the action of temperature and humidity,the bond between the painted layer and the clay surface decreases,and then falls off,loses its original color,and destroys the value of cultural relics.The clay sculptures in Baosheng Temple of more than one thousand years ago,as a typical representative of temples in the southern region of the clay sculpture,in the year high wet climate zone,under the influence of the environment,the dust deposition,cracking,peeling,fading,such as surface degradation,especially surface peeling,faded in the most severe,and cultural value have been severely disrupted.Based on the preservation status of painted clay sculptures in Baosheng Temple,this study conducted a field investigation on Luohan Hall,the attached building of clay sculptures,and analyzed the indoor and outdoor environment of Luohan Hall through continuous monitoring of temperature and humidity environment.Aiming at the problems of unsuitable preservation and excessive fluctuation of temperature and humidity in the preservation environment of clay sculptures,a thermal-humidity coupling numerical model was established to determine the correlation between the temperature and humidity in the preservation environment of Luohan Hall and deterioration of clay sculptures,such as surface peeling.Based on the analysis of the current situation and from the perspective of environmental regulation,the optimized protection scheme was proposed and designed,and the optimized numerical model was established to evaluate the suitability of the optimized measures and determine the deterioration risk of the optimized clay sculptures surface peeling and other diseases.So far,the main conclusions of this study are as follows:(1)The site investigation and disease survey show that Luohan Hall has a firm structure and strong durability.As a historical building,the building itself is well preserved.The disease of clay sculpture has a large distribution area and a serious deterioration degree.(2)The continuous monitoring of temperature and humidity shows that the indoor temperature and humidity in Luohan Hall is greatly affected by the external air environment.The overall temperature and humidity in the interior space are evenly distributed,but the fluctuation is large,especially the relative humidity fluctuates more than 10% for 174 days.On the whole,the temperature and humidity environment of Luohan Hall is not conducive to the preservation of clay sculptures,especially in winter and spring.(3)The numerical simulation results show that the clay sculpture surface temperature stress were less than the minimum stress evaluation,clay sculpture surface loss mainly affected by the moisture fluctuations caused by fluctuations in relative humidity,surface evaporation occurs mainly in the summer,more than 70 days throughout the year,the salt in the clay painting layer is in a cycle of crystallization and dissolution,The risk of efflorescence and peeling on clay surface is high.(4)The evaluation of optimization measures shows that adding glass protective cover can greatly reduce the temperature and humidity fluctuations in the clay sculpture preservation environment,reduce the heat and water transfer on the surface of the Buddha,and have a good promotion effect on alleviating the surface peeling,but adding glass protective cover but not completely closed does not play a role in inhibiting evaporation.On the contrary,the peeling degree of clay surface is increased in spring and summer,and the completely closed glass protective cover can inhibit the evaporation of statue surface to a large extent,so it can be considered to completely closed glass protective cover.Based on the temple clay sculptures located in high-humidity areas,this study explored the influence of temperature and humidity fluctuations in the preservation environment on the deterioration of clay sculptures,and clarified the correlation between the two,providing reference for the environmental monitoring and deterioration risk warning of immovable cultural relics.By evaluating the suitability of the optimized conservation environment,the effectiveness of the conservation measures was discussed,providing a basic reference for the preservation of temple clay sculptures in the same high-humidity area.Words:52000 approximately;Figures: 70;Tables: 10.