摘要
在大量的勘察及试验基础上,将澜沧江某巨型堆积体的形成机制划分为崩塌堵江、冲堆平衡、间歇堆积、河谷再下切四个阶段。运用刚体极限平衡法、有限元强度折减法、基于饱和非饱和理论的有限元法进行堆积体稳定性及地下水渗流分析。结果表明:当蓄水位上升时,堆积体前缘首先发生局部圆弧型滑塌,随后堆积体中部将沿碎石层内部发生折线型深层滑移,最终堆积体将沿基覆界面发生推移型整体失稳破坏;当蓄水位下降时,坡体中部碎砾石层及前缘局部区域构成主要渗流通道,堆积体稳定系数先降后升,但水位总降幅及总历时一定时,堆积体稳定系数总减小量基本相当。回归分析显示,水位骤降速率与堆积体稳定系数日增量成负相关,其相关函数类型为二次抛物线。
Based on a large number of investigations and experiments,this paper divides the formation mechanism of a giant deposit of Lantsang into four stages:slope collapsing and river blocking,scouring and accumulating balance,intermittent accumulation and river valley cutting.According to the analysis of the stability of the deposit and the seepage of groundwater by using the rigid limit equilibrium method,the finite element strength reduction method and the FEM based on the saturated-unsaturated theory,when the water level of the reservoir rises,the front edge of the deposit will firstly collapse in the form of local circular arc,then the middle part of the deposit will slide along the gravel layer,and finally the deposit will push along the base interface.When the water level of the reservoir drops,the gravel layer in the middle of the slope and the local area of the front edge form the main seepage channel,and the stability factor of the deposit first drops and then rises,but when the total drop of the water level and the total duration are fixed,the total decrease of the stability factor of the deposit is basically the same.Regression analysis shows that the rate of sudden drop of water level is negatively related to the daily increment of the stability factor of the deposit,and the correlation function type is quadratic parabola.
作者
胡大儒
肖万春
王晓朋
吴述彧
HU Daru;XIAO Wanchun;WANG Xiaopeng;WU Shuyu(Power China Guiyang Engineering Corporation Limited,Guiyang,Guizhou 550081,China)
出处
《水利与建筑工程学报》
2020年第5期137-142,共6页
Journal of Water Resources and Architectural Engineering
基金
国家重点研发计划(2017YFC1501100)
中国华能集团科技项目(HNKJ16-H15)。
关键词
澜沧江
堆积体
成因机理
失稳模式
渗流
数值模拟
Lantsang
deposit
formation mechanism
instability mode
seepage
numerical simulation
