基于钻孔电视的深部岩体节理三维网络模拟

3D Network Simulation of Deep Rock Joints Based on Borehole TV

为了准确模拟岩体节理的空间分布,评价高放废物地质处置库围岩的稳定性,先通过调查露头节理数据,运用概率统计理论进行节理几何特征模拟,再利用Monte-Carlo法来模拟节理空间分布特征,并以高放废物地质处置新疆预选区天湖地段花岗岩体为研究对象,通过钻孔电视调查不同深度节理几何特征,划分钻孔岩体结构均质区,提出钻孔节理产状、大小、密度的统计方法和计算公式,以均质区建立节理三维网络模型并通过数据对比法进行模型验证。结果表明:1)利用列联表卡方检验和重叠窗口法可将天湖钻孔岩体划分为0~90、120~240、270~360和390~600 m等4个均质区;2)利用SPSS软件以及基于节理直径、迹长和隙宽之间的数量关系得出节理产状服从正态分布,节理直径服从负指数分布;3)通过数据对比法得出模型统计和现场测量的节理平均产状数据相差±3°以内,平均直径相差±1 m以内,平均面密度相差±0.01 m^(-2)以内,从而验证了Monte-Carlo法建立的节理三维网络模拟的准确性。

In order to accurately simulate the spatial distribution of rock joints to evaluate the stability of surrounding rock in high level radioactive waste geological disposal repository, at first the probability statistics theory was introduced to simulate the geometric characteristics of joints through the investigation of outcrop joint data, then by using the Monte-Carlo method the spatial distribution characteristics of the joints of the granite rocks in the Tianhu district in Xinjiang were simulated, which is a preliminary area for the disposal of high-level radioactive waste. The authors studied the different depth of joint geometrical characteristics through borehole TV, circled the homogeneous areas, proposed statistical methods and calculation formulas for borehole joint occurrence, density, and size, and finally established a joint 3D network model. The results show that: 1) Using the chi-square test of the list table and the overlapping window method, the rock mass of the Tianhu borehole is divided into 0-90,120-240,270-360, and 390-600 m homogeneous zones;2) Using SPSS software and based on the quantitative relationship between joint diameter, joint trace length, and gap width, the joint occurrence and diameter were in normal and negative exponential distribution respectively;3)The difference between the model statistics and the field measured joint occurrence is within ±3°, the average diameter is within ±1 m, and the surface density is within ±0.01 m^(-2) through data comparison, which verifies the accuracy of the 3 D network simulation of the joint established by the Monte-Carlo method.