Study On Causes Of Formation & Countermeasures Of High Mineralized Groundwater Quality In Hydroelectric Power Station Of Bapanxia

Red clay is a sort of sophisticated engineering geology body which widely ranges to the southwest, northwest and midland of China. In the region of red clay, the corrosiveness of groundwater to structure and stuff of permanent works such as dams of hydroelectric power station is prevalence. It makes potential safety hazard to dam body, and sometimes it brings about the dilatational strain, craze leakage of concrete. It is a familiar problem here and abroad. There are analogous problems need to be resolved at irrigation-hydroelectric projects construct to red clay, such as Bapanxia and Yanguoxia.This paper takes Bapanxia hydroelectric power station for a case, and proceeded researches as follows aim at the abnormal occurrences of groundwater quality at dam site. First of all, it proceeds statistical analysis to groundwater quantity data of hydroelectric power station in the last ten more years, revealing the distribution characteristics from time and space, and finds that the ground water quality of the left bank and abutment in a high mineralized condition long-period. Then, it uses conventional and fuzzy clustering techniques to analyze the groundwater quantity data of selected years. Secondly, it uses program solution in EXCEL instead of the conventional Simplex Method to simulate and calculate the mutual interaction among water,rocks and dam. The results indicate that the groudwater to concrete erosion effect can occur spontaneously in normal atmospheric and pressure.From the results, it can draw the conclusion that the ample sulphate mineral in evaporite is main source to SO₄^2- in groundwater, the terrace landform on the left bank is propitious to the recharge of rainfall,agricultural irrigation and resident living water, and the impermeable leak caused by drainage obstruction and bad conjugation grout curtain makes the maple groundwater marshal in the left bank and influence the monolith of left riverbed. These were the comprehensive results that high mineralized groundwater the left bank was corraded stronger than the right bank. From the material resources, the supplies,flow off and drainage of groundwater, the grout curtain and the material science put forward corresponding countermeasure aims at the erosion of the high mineralized groundwater to concrete.In the region of red clay, the erosion not only occurs in water and hydropower projects, but also appears in railway and highway's roadbed and so on. The results of the researches in this paper can furnish reference for similar project construction.