某抽水蓄能电站高压渗透试验分析

Analysis of HPPT Results From a Water-pumped Storage Power Plant

岩体的渗透稳定性关系到地下洞室围岩体的稳定性。以一抽水蓄能电站设计阶段进行的高压渗透试验为例,重点探讨了试验过程中流量Q与压力P之间的关系,岩体的渗流性态以及岩体的允许水力坡降等重要方面。根据不同的P^Q关系曲线,得到呈相对闭合的裂隙明显存在临界水头压力,而具有一定开度的裂隙则不然;随着水头压力的增大,岩体的渗流性态渐趋敏感;而在较高水头压力的持续作用下,岩体的允许水力坡降值则有减小之势。因而认为,进行高压渗透试验,可以更为真实地反映深埋地下洞室围岩体的渗流状态。

The stability of a underground chamber is closely related to the seepage stability of rock masses concerned. A higher pressure permeability test （HPPT） in situ is mentioned, taken a case study as an exampie. The interrelationship between flow rate （ Q ） and pressure （P）, seepage behavior and permissible hydraulic gradient in the process were analyzed with a greater detail. It is known from the results that there was a critical hydraulic pressure as to a closed fissure, whereas there was not as to a fissure with some width. As the increase of hydraulic pressure, the seepage behavior tended to be more sensitive. Under higher hydraulic pressure, the pemaissible hydraulic gradient had the tendency of decrease. Therefore, it is thought that the seepage behavior of rock masses surrounding the underground chamber can be reflected really by carrying out HPPT