摘要
为解决坝基岩体质量指标参数不确定性问题,特别是处于相邻等级分界线附近的岩体分类问题,本文提出基于优化组合权-模糊可变集的坝基岩体质量分级模型。首先选取岩石单轴饱和抗压强度(R_(c))、结构面间距(J_(d))、岩石质量指标(RQD)、完整性系数(K_(v))、声波纵波速度(V_(P))和地应力修正系数(Q)等6个主要影响指标,将每个指标划分为5个等级;然后利用改进的序关系分析法(G1法)和最大离差法分别确定指标的主客观权重,通过矩估计法优化指标的组合权值,同时借助单因素轮换法(OAT)分析指标的敏感性;最后以金沙江旭龙水电站坝基岩体的7个标准样本作为实例,应用模糊可变集模型进行坝基岩体质量分级评判,将分级结果与云模型的判定结果进行了对比。结果表明:7个样本中,除岩体样本N3的分级结果存在差异外,其余样本的分级结果均吻合;根据野外实地勘测结果,样本N3属于Ⅱ类的概率高达80%,与本文分级结果相吻合,验证了本文方法的可靠性,也弥补了云模型关于评判坝基岩体质量的不足。此外,指标的敏感性由高到低的排序为R_(c)>RQD>K_(v)>V_(P)>Q>J_(d)。
In order to solve the uncertainty problem of quality index or parameters of rock mass in dam foundation,especially the classification of rock mass near the boundary of adjacent grades,a quality-classifying model of the rock mass in dam foundation is proposed based on the optimized combination weights and fuzzy variable sets.Firstly,a total of six main influencing indicators are selected,including uniaxial saturated compressive strength of rock(R_(c)),spacing of structural planes(J_(d)),rock quality designation(RQD),fissure coefficient(K_(v)),P-wave velocity of sound-wave(V_(P)),and stress correction coefficient(Q).Each of the indicators is divided into five levels.Then,the improved order relation analysis method(G1)and the maximum deviation method are used to determine the subjective and objective weights of each indicator,respectively.Following this,the combined weights of the indicators are optimized by the moment estimation method.Meanwhile the sensitivity of the index is analyzed by one-at-a-time(OAT)method.Finally,we take seven standard samples of the rock mass in the dam foundation of the Xulong hydropower station on the Jinsha River as an example,and apply the fuzzy variable set model to compare the classification results with those from the cloud model,and the results show that except the Sample N3 in the seven samples,all the other classification results are consistent;According to the results by the field survey,the Sample N3 belongs to the gradeⅡwith the high probability of 80%,being consistent with the classification results in this study,which not only verifies the reliability of the proposed method,but also makes up for the lack of cloud model on evaluating the quality of the rock mass in the dam foundation.In addition,the sensitivity ranking order of the indicators from high to low is R_(c)>RQD>K_(v)>V P>Q>J_(d).
作者
柴乃杰
周文梁
Chai Naijie;Zhou Wenliang(School of Traffic&Transportation Engineering,Central South University,Changsha 410075,China)
出处
《吉林大学学报（地球科学版）》
CAS
CSCD
北大核心
2023年第2期514-525,共12页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(71871226,U1934216)
中国国家铁路集团有限公司系统性重大课题(P2021X008)。
关键词
坝基岩体质量
G1法
最大离差法
矩估计法
模糊可变集
综合级别特征值
quality of rock mass in dam foundation
G1 method
maximum deviation method
moment estimation method
fuzzy variable set
characteristic value of comprehensive level
