摘要
某水电站坝址区域多分布含软弱夹层软岩,对水电站坝基不均匀沉降及抗滑稳定性起控制性作用。针对含软弱夹层软岩开展分级加载的剪切流变特性试验,研究含软弱夹层软岩在不同正应力与剪切应力作用下的剪切流变力学特性。本文采用Burgers流变模型描述含软弱夹层软岩的剪切试验结果。某水电站含软弱夹层软岩分级加载过程中的力学模型参数通过Quasi-Newton法搜索得到。根据分析试样的应变与时间关系曲线,得到不同应力水平条件下相对应的剪应力-应变等时簇曲线,求得软弱夹层的长期内摩擦系数为0.245,为瞬时内摩擦系数的90.7%;长期内聚力为0.0131 MPa,为瞬时内聚力的93.6%,为坝基长期变形及稳定分析提供参数依据。
The dam site area of a hydropower station is predominantly composed of stratified soft rock with weak interlayers,which govern the differential settlement and sliding stability of the dam foundation.To investigate the shear rheological behavior of soft rock containing weak interlayers,stepwise loading shear creep tests were conducted under varying normal and shear stresses.The Burgers rheological model was adopted to characterize the shear response.The constitutive parameters of the stratified soft rock during stepwise loading were identified via the Quasi-Newton optimization algorithm.Based on strain-time curves derived from experimental data,isochronous shear stress-strain clusters were established for distinct stress levels.The results indicate that the long-term internal friction angle of the weak interlayers corresponds to a coefficient of 0.245(90.7%of the instantaneous value),and the long-term cohesive strength is 0.0131 MPa(93.6%of the instantaneous cohesion).These parameters provide critical inputs for long-term stability assessment and deformation prediction of the dam foundation.
作者
王永伟
杨茂强
王艳琴
汪斌
WANG Yongwei;YANG Maoqiang;WANG Yanqin;WANG Bin(The Fifth Engineering Branch,China Communications Second Navigation Engineering Bureau Co Ltd,Wuhan 430012,China;Key Laboratory of Geotechnical Mechanics and Engineering,Ministry of Water Resources,Yangtze River Scientific Research Institute,Wuhan 430010,China)
出处
《土木工程与管理学报》
2026年第1期62-68,共7页
Journal of Civil Engineering and Management
关键词
含夹层软岩
剪切流变试验
Burgers流变模型
本构模型参数辨识
流变长期强度
soft rock with interlayers
shear rheological test
Burgers rheological model
constitutive model parameter identification
long-term rheological strength
