乐山大佛胸部渗水病害特征研究  

Study on Characteristics of Water Seepage in Chest of Leshan Giant Buddha

作　　者：孙博[1,2] 张虎元 张鹏[2] 申喜旺 杨天宇 SUN Bo;ZHANG Huyuan;ZHANG Peng;SHEN Xiwang;YANG Tianyu(College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China;Northwest Research Institute Co.,Ltd.,of C.R.E.C,Lanzhou 730000,China;Management Committee of Leshan Giant Buddha Scenic Area,Leshan 614000,China)

机构地区：[1]兰州大学土木工程与力学学院,甘肃兰州730000 [2]中铁西北科学研究院有限公司,甘肃兰州730000 [3]乐山大佛风景名胜区管理委员会,四川乐山614000

出　　处：《西南交通大学学报》2023年第5期1037-1044,共8页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(51808246);国家重点研发计划(2019YFC1520500)。

摘　　要：为给乐山大佛渗水病害治理及后期保护研究提供科学依据,本研究首次对乐山大佛渗水及大气降水进行定量监测采样,分析大佛渗水来源及其特征,并结合水化学性质和岩石组成对“大佛砂岩”风化机理进行了研究.研究表明:乐山大佛胸部渗水在平水期与枯水期主要补给来源为地下水,丰水期主要补给来源为大气降水;大佛胸部渗水含有大量溶解质组分,pH平均值为7.70,2009年之后乐山市降水年平均pH>5.60且逐年增高,至2015年全年降水pH平均值大于7.00,降水已由酸性转为碱性;大佛胸部渗水水化学类型为碳酸盐类-钙组-Ⅱ型与硫酸盐类-钙组-Ⅲ型,阳离子以Ca^(2+)为主,阴离子以SO_(4)^(2-)与HCO_(3)^(-)为主;大佛胸部岩石主要成分为CaCO_(3)和SiO_(2),在空气和水存在的情况下容易发生溶蚀,岩石风化对大佛渗水中离子贡献超过90%,H_(2)CO_(3)与H2SO_(4)共同参与了“大佛砂岩”的风化.In order to provide a scientific basis for water seepage control and later protection research of Leshan Giant Buddha,this study conducts quantitative monitoring and sampling of water seepage and atmospheric precipitation of Leshan Giant Buddha for the first time,analyzes the source and characteristics of water seepage,and studies the weathering mechanism of sandstone combined with water chemical properties and rock composition.The study shows that groundwater is the main source of water supply to water seepage in the chest of Leshan Giant Buddha during the level and dry periods,and atmospheric precipitation is the main source of water supply during the wet period.Abundant solute compositions are found in water seepage samples,with the pH value being 7.70.Since 2009,the annual average pH value of precipitation in Leshan City is higher than 5.60 and increases year by year.Until 2015,the annual average pH value of precipitation is higher than 7.00,and the precipitation has changed from acidic to alkaline.The hydrochemical type of water seepage in the chest of Leshan Giant Buddha is carbonate-calcium-typeⅡand sulfate-calcium-typeⅢ.The cation is mainly Ca^(2+),and the anion is SO_(4)^(2-)and HCO_(3)^(-).The rock in the chest of Leshan Giant Buddha is mainly composed of CaCO_(3)and SiO_(2).Therefore,the rock is prone to being corroded after being exposed to air and water.Rock weathering contributes more than 90%of the ions in the seepage water sample,and H_(2)CO_(3)and H2SO_(4)jointly affect the weathering of sandstone in Buddha.

关 键 词：乐山大佛 渗水监测 大气降水 岩石风化 

分 类 号：P642.5[天文地球—工程地质学]