【作者】 吴顺华；

【导师】 刘建刚；

【作者基本信息】 河海大学 ， 地质工程， 2005， 硕士

【摘要】 随着科学的发展和技术的进步,世界上各种用途水工隧洞工程建设得到了突飞猛进的发展,隧洞的高外水压力和突涌水问题就会变得更加突出,目前已成为隧洞设计和施工中亟待解决的难题。外水压力的确定方法目前主要有外水压力作用系数法和渗流场分析方法,本文在总结前人研究成果的基础上,针对隧洞的突涌水和高外水压力问题,创造性地用水文地球化学方法展开了详细的分析和研究,提出一种确定外水压力的全新方法。主要原理如下:水中溶解气体分压的大小与水头高低有关。在相同水文地质条件下,水中溶解CO2分压与水头呈线性相关关系,因而通过已知水体或钻孔中地下水CO2分压与水头大小的关系,现场测定隧洞渗出水中CO2分压,间接确定渗水处外水压力值。本文介绍了一种现场快速测定地下水水样中CO2总浓度的方法一气敏电极法,根据基于活度计算的碳酸平衡理论确定水样中HCO3浓度占CO2总浓度的百分比a1,由此得到HCO3。浓度,并根据pH值计算出CO2分压。经陈村水电站廊道观测孔和句容抽水蓄能电站勘探平硐验证,这种方法是可行的。更多还原

【Abstract】 With the development of science and technology, various tunnel projects develop quickly in the world, the high external water pressure and flow are the most important problems faced in the tunnel design and construction.At present there are two methods can be used to define the high external water pressure. The first is the function coefficient method of external water pressure; the second is the analytical method of rock seepage field. Concentrating on the questions of high external water pressure and flow of tunnels, author analyzes and studies in detail with hydrogeochemical method, poses a new method to define external water pressure. The Fundationals as follows:Correlation between CO2 pressure and hydraulic head is studied. In the same geological unit CO2 pressure in water is linear correlation to hydraulic head, Based on the correlation and the tested tunnel CO2 pressure can indirectly lead to external water pressure.The paper introduces a method to measure the total CO2 in the groundwater quickly - gas sensitive electrode method. According to the theory of carbonate balance based on activity, can calculate the HCO3-’s percentage of total CO2, then with pH value define CO2 pressure.It is practical for this method to two examples of ChenCun hydropower station and JuRong pumped-storage power station, and hydrogeochemical method of defining external water pressure be testified to be correct.更多还原