算井子地段地表岩体结构面发育程度评价

Evaluation of structural plane development for surface rock mass in Suanjingzi area

为了探讨结构面发育程度对高放废物地质处置库选址的影响,以甘肃北山算井子地段岩体为研究对象,通过调查地表岩体节理和断层几何特征,采用数理统计方法获得节理产状、密度、间距、迹长和断层产状、断裂带宽度和断层泥厚度等统计数据,提出多尺度结构面综合评价指标来评价岩体结构面发育程度。结果表明:BS22和BS23钻孔周围分别发育4个和5个节理优势组,节理产状服从正态分布;BS22和BS23钻孔周围岩体节理平均中点面密度分别为0.037 m^(-2)和0.035 m^(-2),平均迹长分别为20.38 m和17.39 m;解译出断层F1产状为35°∠85°,延伸长度为4.49 km;BS22钻孔周围岩体结构面发育程度更低,更适合作为我国高放废物处置库建造场址。

To discuss the influence of the development degree of structural plane on the location selection of high-level radioactive waste repository,the rock mass of Suanjingzi area in Beishan,Gansu Province,was taken as the research object,and the statistical characteristics,such as the joint occurrence,density,spacing,trace length,fault occurrence,width of fault zone and thickness of fault gouge,were obtained through the mathematical statistics based on the geometric characteristic investigation of joints and faults in the superficial rock mass.Then,a multi-scale structural surface comprehensive evaluation index was proposed to evaluate the structural plane development in the superficial rock mass.The results showed that there were 4 and 5 dominant joint groups around BS22 and BS23 boreholes,and joints obeyed the normal distribution.The midpoint surface densities of joint traces around BS22 and BS23 boreholes were 0.037 m^(-2) and 0.035 m^(-2) respectively,and the average trace lengths were 20.38 m and 17.39 m respectively.The fault F1 was interpreted as 35°∠85°,with an extension length of 4.49 km.The structural plane of rock mass around the BS22 drill hole was less developed and more suitable for the construction site of high-level radioactive waste repository than the BS22 borehole.