Research On The Survey And Distribution Of Salt In The Wall Of Suoyang City Ruins In Gansu Province

Suoyang city ruins which is composed of inner city and outer city is located in the Gobi desert at the south of Qiaozi village in Suoyang town of Guazhou county in Gansu Province. The location of Suoyang city ruins is about 7km away from Qiaozi village in the north direction, 62km away from county in the northwest direction,22km away from Suoyang town in the west direction,7km away from Jian Qianzi river of northen ChangShanzi mountain in the south direction and 22km away from east Thousand Buddha Caves in the east direction. Suoyang city ruins which is in the list of the fourth national key cultural relics protection unit announced by State Council in November 1996 is one of the best conserved ancient city of Han-Tang dynasty at present in China.Suoyang city ruins has been affected by various diseases as the influence of the natural and human factors. Salt hazard which caused by the migration of soluble salt are serious damage for Suoyang city ruins in the form of flaky peeling, the root's decay and so on. At present there are less in-depth research on salt hazard of earthen ruins and it caused great difficulties for salt hazard treatment in earthen ruins. This thesis begins with the investigation on the types of diseases in the wall of Suoyang city. Through the experiment on the soil samples from 26 wall sections and 5 collapsed wall brick. The salt distribution status in the wall of Suoyang city and the soil nature of Suoyang city ruins can be obtained exactly. We also discussed the salt distribution changes of the wall section in detail. This thesis can provide basic data for future research on salt hazard formation mechanism. Main contents can be divided as the following sections:(1)Investigation and analysis on the conservation status and disease type of Suoyang city ruins. Most of the outer city has been disappeared, the west Wall, the south wall and the north wall are relatively complete. While the east wall has been serious damaged by weathering. followed by the middle wall. Salt hazard in the wall of Suoyang city are mainly in the form of flaky peeling, the root's decay and block off and it has relation with other diseases through the avenues of wind,water, temperature and earthquake.(2)Investigation on the composition of soluble salt and soil type in the wall of Suoyang city ruins by means of ion chromatography and laser particle size analyzer. Studies have shown that the major anion of soluble salt in the wall of Suoyang city ruins are SO42-,Cl-,NO32- and the major cation are Na+,K+,Mg2+.The major soluble salt in in the wall of Suoyang city are NaCl, NaSO4.The soil nature of Suoyang city ruins is the silty clay with low porosity,low water content,high density and high clay content.(3)Research on the salt distribution in the wall of Suoyang city ruins. Studies show that the total soluble salt content increase from the inner of the wall to the surface of the wall and decrease from bottom of the wall to the top of the wall.(4)Analysis on the soluble salt content of collapse wall brick sample and crust sample in the wall of Suoyang city ruins.Studies show that the soluble salt content of crust sample are extremely high in the outside of the north wall,west side of the middle wall and both sides of south wall. Varied from 10000mg/kg-11500mg/kg.The crust in the outside of the north wall has the highest soluble salt content. The soluble salt content from collapse wall brick are lower than the wall surface soluble salt content.