摘要
基于裂面多迹线及支持向量回归预测模型,求得砂岩劈裂裂隙面的节理粗糙度系数(JRC)。以ELE岩石渗透仪为试验平台,分析不同JRC的砂岩劈裂裂隙面在围压、轴压共同作用下的渗流特性。结合试验数据分析得出,渗流量随围压呈递减的幂函数关系,随轴压呈递增的正比例函数关系,随JRC呈递减的线性函数关系。将3个函数依次复合,构造了一个基于JRC、围压、轴压值的渗流量预测模型。在提出一种模型参数反演简便方法的基础上,得到了三维预测图形,预测值与试验值的误差较小,证明了渗流量预测模型的有效性。为对改变界面正应力进行控渗的工程行为进行指导,提出高效和有效控渗界面正应力临界点两个新概念,并基于渗流量预测模型提出一种客观的方法来确定高效和有效控渗界面正应力临界点。结果表明,高效控渗界面正应力临界点对JRC与轴压均不敏感,其值维持在0. 38 MPa;但有效控渗界面正应力临界点均敏感,且在某JRC下,渗流量随着有效控渗临界点的增大而呈指数增大,其值主要介于1. 00 MPa与2. 50 MPa之间。
Based on multiply trace of fracture surface and supporting vector of regression prediction model,calculate joint roughness coefficient( JRC) of fissure surface in sandstone. According to the experiment results in ELE rock penetrometer,analyze seepage characteristics of different JRC in fissure surface of sandstone under the confining pressure and axial pressure. Combined with experimental data analysis,deduce the decreasing power function between seepage flow and confining pressure,the increasing proportional function between seepage and axial pressure,the decreasing linear function between seepage and roughness. Combine the three functions in turn to estab-lish a seepage flow forecasting model involving JRC,confining pressure and axial pressure. Based on a simple method of model parameter inversion,the predictive figure of three dimension is derived. The error between the predictive value and trial value is small,which proves the effectiveness of this seepage flow forecasting model. In order to guide the engineering behavior of changing interfacial stress for controlling seepage,two new concepts of efficient and effective critical points of controlling seepage interfacial stress are proposed. To determine the two critical points,an objective method is proposed based on the seepage flow forecasting model. The result shows that the efficient critical point of controlling seepage interfacial stress is not sensitive to JRC and axial pressure,and its value is maintained at 0. 38 MPa. However,the effective critical point of controlling seepage interfacial stress is sensitive.Under certain JRC,the seepage flow increases exponentially with the effective critical point,and the value is mainly between 1. 00 MPa and 2. 50 MPa.
作者
马德宜
刘杰
李建林
高进
黄宜胜
MA Deyi;LIU Jie;LI Jianlin;GAO Jin;HUANG Yisheng(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education,China Three Gorges University, Yiehang 443002,China;College of Science,China Three Gorges University,Yichang 443002,China)
出处
《自然灾害学报》
CSCD
北大核心
2018年第6期109-119,共11页
Journal of Natural Disasters
基金
成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金项目(SKLGP2016K023)
国家自然科学基金项目(51439003
51579138)
湖北省自然科学基金项目(2015CFB545)
三峡库区地质灾害教育部重点实验室开放基金项目(2015KDZ11)
三峡大学科学基金项目(KJ2013B030
KJ2013B031)~~
关键词
节理粗糙度系数
裂隙渗流
围压
轴压
界面正应力
临界点
JRC
seepage law of splitting
confining pressure
axial pressure
interfacial stress
critical point
