摘要
地震作用导致的反倾边坡失稳破坏会诱发严重的地质灾害,因此对地震作用下反倾边坡稳定性、破坏模式及影响因素的研究是十分必要的。文章基于Scavia模型,采用离散元UDEC软件探讨双向地震作用下反倾边坡动力响应规律;基于正交试验设计法,考虑坡高、坡角、岩层倾角、岩层厚度、岩块底面倾角、节理摩擦角、地震烈度7个影响因素,设计18组正交试验,利用失稳位移比进行敏感分析。结果表明,在地震作用下,反倾边坡倾倒破坏经历了位移启程、位移累积及失稳3个阶段;坡体水平向、竖向加速度均存在高程及坡表放大效应,峰值加速度(PGA)系数随坡体高程增加呈现线性增加,其中缓倾裂隙面上部放大效应更加明显,且坡体上岩块主要受水平方向地震波影响,受竖向地震波影响很小;最后,正交试验表明地震烈度、坡高、岩层厚度、岩块底面倾角对反倾边坡稳定性具有显著影响,而坡角、岩层倾角及结构面摩擦角等对反倾边坡稳定性影响较小。
The instability and failure of counter-tilt slopes induced by earthquakes may trigger severe geological disasters,highlighting the necessity to study their stability,failure mechanisms,and influencing factors under seismic conditions.Based on the Scavia model,this study utilizes UDEC software to investigate the dynamic response of counter-tilt slopes under bidirectional seismic excitation.An orthogonal experimental design comprising 18 test groups was employed,considering seven factors:slope height,slope angle,stratum dip angle,stratum thickness,rock block base dip angle,joint friction angle,and seismic intensity.Sensitivity analysis was performed using the instability displacement ratio.The results indicate that(1)toppling failure of counter-tilt slopes under seismic loading progresses through three stages:displacement initiation,displacement accumulation,and instability.(2)Horizontal and vertical accelerations exhibit amplification effects along elevation and slope surfaces.The peak ground acceleration amplification coefficient increases linearly with elevation and is pronounced near gently inclined fractures.Horizontal seismic waves primarily drive rock block responses,while vertical wave effects are negligible.(3)Orthogonal tests reveal that seismic intensity,slope height,stratum thickness,and rock block base dip angle considerably influence slope stability,whereas slope angle,stratum dip angle,and joint friction angle have limited impact.
作者
谌永刚
张俊
王寿龙
CHEN Yonggang;ZHANG Jun;WANG Shoulong(The Eighth Construction Co.,Ltd.of China Construction Sixth Engineering Bureau,Hefei 230051,Anhui,China)
出处
《地震工程学报》
北大核心
2025年第4期876-885,共10页
China Earthquake Engineering Journal
关键词
反倾边坡
离散元
动力响应
正交试验
counter-tilt slope
discrete element
dynamic response
orthogonal test
