大型地下水封石油洞库裂隙岩体各向异性渗透特性的分析和应用

ANALYSIS OF ANISOTROPIC PERMEABILITY OF FRACTURED ROCK MASS AROUND A LARGE WATER-SEALED UNDERGROUND OIL STORAGE CAVERN AND ITS APPLICATION

依托黄岛地下水封石油洞库工程,研究裂隙岩体各项异性渗透特性。考虑裂隙结构面的粗糙情况,对单一平板裂隙渗流立方定律进行修正,并推导出对应的三维裂隙岩体渗透张量计算式。根据油库库区水文地质资料可知:基岩裂隙在空间上的分布具有明显的方向性,将库区地质结构分成五个区,计算各分区裂隙岩体的渗透张量。建立基于裂隙岩体各向异性渗透张量理论的三维地下水非稳定流数值模型,运用该模型模拟施工不同阶段库址区渗流场的变化。通过对模拟结果和观测资料的对比分析,表明采用该模型的模拟结果比较符合实际,可以预测开挖及运营期间渗流场的变化。

Based on Huangdao undergroud oil storage project sealed by groundwater,the anisotropic permeability characteristics of fractured rock mass were studied.Considering the roughness of the fractured surface,the cubic-law of seepage flow through a single fracture was modified,and the corresponding three-dimensional seepage tensor formula for fractured rock mass was derived.According to the hydrogeological data of the reservoir,the distribution of bedrock fissures in space is obviously directional.The geological structure in reservoir was divided into five areas,and the permeability tensor of the fractured rock mass in each partition was calculated.Based on the anisotropic permeability tensor theory of fractured rock mass,a three-dimensional numerical model of unsteady groundwater flow was modeled,which was used to simulate the variation of seepage field in different construction progresses.By comparing the simulation results with the observation data,the simulation results were more in line with the actual situation.The model could be used to predict the changes of seepage fields during excavation and operation.