澜沧江中游某崩塌堆积体变形空间效应研究

Spatial effects of the deformation of a debris on the middle-reach of Lancang River

某崩塌堆积体范围内布置有公路、缆机平台、电站进水口等重要建筑物。其变形稳定性直接影响到治理工程设计、施工安全以及电站的运行。因此,文章在对其环境地质条件、物质结构、形成机制分析的基础上,对其变形空间效应作系统的地质分析;并建立了相应的三维地质力学模型,应用FLAC 3D快速拉各朗日差分程序对其空间变形特征进行了详细的分析。结果表明:收口转向及变形收敛特征使得堆积体下部形成一个"支撑拱",从而阻碍了上部堆积体向下部的变形与位移,利于堆积体的稳定;同时,三维数值模拟结果也表明:堆积体的变形具有明显的空间效应。其位移矢量表现出一定的收敛性,且变形主要分布在1360～1650m高程;变形方式表现出一定的分区特征,表现出后缘压缩固结,中部滑移,前缘受阻压缩的位移特征。纵向具有明显的收口效应;横向上比较来看,也存在变形受阻的收口特征;收口范围主要集中在1330～1440m高程范围。

Some important structures as road, cable way deck, intake etc will be built on one debris, so the deformation and stability of the debris are the substantial foundation to the control design, which will influence the safety of construction and operation of the hydroelectric station. So in this paper, based on the study of environmental geology, composition and structure and formation mechanism of the debris, geological characteristics of the spatial deformation effects were analysed systematically. Then three-dimensional geological and mechanical model was established, and study of spatial deformation characteristics with FLAC-3D (Fast Lagrangian Analysis of Continua) was detailed. The results show that there appears a supporting arch holding up the accumulative displacement downward in the lower of the debris dueing to the characteristics of constriction and planar turn, convergent deformation. And the FLAC-3D simulation also indicates: deformation of the debris presents obvious spatial effects, the vector distributing convergent, the deformation concentrating between the elevation 1360?m～1650?m; it can be sectionalized three parts owing to the deformation style; trailing compression and subsidence, middle sliding, and front holding up and compression; presenting the constriction between the elevation 1330m～1440m longitudinally and transversely.