崖面降雨与热辐射对莫高108窟墙体内水盐运移的影响  

Effects of Rainfall Infiltration and Solar Radiation at Cliff Surface on Water and Salt Transport in the Wall of Cave 108 Mogao Grottos

作　　者：周启友[1] 宋云 宋震[1] 陈港泉[2] 郭青林[2] 王彦武[2] 

机构地区：[1]南京大学地球科学与工程学院,南京210023 [2]敦煌研究院保护研究所,敦煌736200

出　　处：《高校地质学报》2017年第4期615-625,共11页Geological Journal of China Universities

基　　金：科技支撑计划项目(2014BAK16B01);国家自然科学基金(41172208)联合资助

摘　　要：通过引入高放废物地质处置中水—热—力—化耦合模拟的概念,实现了对莫高108窟及其非规则墙面边界的三维剖分和降雨入渗与辐射通量密度变化条件下的水、热、汽和盐的耦合模拟。结果表明来自深部地下水的毛细上升作用以及洞窟东侧崖面上的降雨入渗作用是洞窟墙体内水分的主要来源,而洞窟东侧崖面上长期的太阳辐射作用则是洞窟墙体内重要的能量来源。两种作用方向一致,共同叠加,促使着水分、热量、盐分以及水汽总体上由东向西运移,并在洞窟南北墙体的底层由墙体内部向墙体表面迁移,长期作用形成盐害。这一模拟结果与108窟盐害主要出现在底层以及窟内温度、湿度和压力的观测结果相吻合。Based on the concept of hydro-thermo-mechanical-chemical coupled numerical simulation that is used in high-radioactive nuclear waste geodisposal, and a successful three-dimensional element division for the cave 108 of Mogao Grottos with irregular cliff surface, a coupled simulation for hydro-thermo-salt transport in the cave was conducted under variable rainfall and solar irradiance input boundary conditions. The results indicate that the capillarity from deep groundwater and the rainfall infiltration on the cliff surface are the main processes providing moisture to the cave, and the long term solar radiation on it is the heat sources of the cave. The rainfall infiltration and solar radiation work jointly, thus driving the moisture, heat, salt and vapor to flow from east to west side of the cave. As a result, the moisture and salt move towards the wall surface near the ground and the painting damage from salt accumulation occurs there.These results coincide with the fact that painting damage mainly are found at the near surface of the cave and with the observations of air temperature, humidity and pressure in the cave.

关 键 词：崖面 降雨入渗 太阳辐射 水盐运移 莫高窟 

分 类 号：P641.2[天文地球—地质矿产勘探]