大亚湾花岗岩某钻孔雨季水位持续走高原因探析  

An analysis of the continual rise in groundwater levels in a rainy season at one borehole in granite near the Daya Bay

作　　者：尚彦军[1] 金维浚[1] 袁广祥[2] 李坤[1] 孙元春 

机构地区：[1]中国科学院地质与地球物理研究所页岩气与地质工程重点实验室,北京100029 [2]华北水利水电学院资源与环境学院,河南郑州450011 [3]铁道第三勘察设计院集团有限公司,天津300142

出　　处：《水文地质工程地质》2017年第6期15-24,共10页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金面上项目(41372324)

摘　　要：作为弱含水层或找水贫困区的花岗岩体,其地下水位变化受裂隙连通性和大气降水影响,出现波动是正常现象。然而在雨季钻孔水位一周内出现近40 m暴涨,且基本维持在高水位持续约3个月后,又跌落回正常水位波动,似乎不常见。以大亚湾中微子试验隧道工程地质勘察钻孔ZK3为例,连续开展两年水位动态观测,监测到上述水位剧烈涨落现象。结合该区水文地质条件、地质构造和岩体结构、降雨量日变化,分析了产生这一奇特现象的原因。很多浅表缓倾节理和构造成因陡倾节理组合成多个不同方向和长度的结构面网络,是水不规则运移和局部储存的控制性结构,雨季开始和结束时不同深度裂隙连通导水差别很大应是水位突变的重要原因。即雨季地表径流很大部分是由于下部裂隙被水充满和饱和,地表产流率高,而旱季深部水腾空或不饱和,浅表水才容易向深部渗透回落。初步提出的水和可能的密闭气体联合作用导致雨季水位高涨突变,或许是需要关注的花岗岩裂隙水的一个重要特征。The sudden fluctuation in groundwater levels in granite （ usually low in yield to wells） is influenced by the connectivity of fissures and precipitation. This phenomenon is abnormal that groundwater levels rose by more than 40 m within a day and returned to normal groundwater levels within a day after a few months. In this paper, more than 2 hydrologic years＇ dynamic observation of the groundwater levels was Daya carried out in the ZK3 geological borehole in the Jiangmen Underground Neutrino Observatory near the Data Bay. Based on the hydrogeological conditions, geological structures, rock mass structures and the daily variation in rainfall in the study area, the reason for this specific phenomenon is analyzed. Shallow-dipping and steeply-dipping discontinuities with various orientations and lengths control the structure of the irregularity migration of groundwater. The distinctly differential groundwater transmissibility of the discontinuities at various depths before and after the rainy season is a significant factor contributing to sudden change in groundwater levels. In the rainy season, most of the surface runoff due to the underpart fissures is saturated with water, the surface runoff rate is high, the deep water is empty or is not saturated in the dry season, and the shallow water is easy to penetrate to the deep.

关 键 词：大亚湾 花岗岩 钻孔水位 气体压缩 裂隙水 弱含水层 

分 类 号：P641.135[天文地球—地质矿产勘探]