顺向高边坡与偏压隧洞开挖的稳定性分析

发布时间：2018-04-14 22:08

本文选题：涔天河水利枢纽 + 顺向边坡　；参考：《水电能源科学》2016年04期

【摘要】：针对顺向高边坡、偏压隧洞工程中岩土参数不确定、地质条件特殊及工况复杂等问题,以涔天河水库扩建工程(#1泄洪洞出口顺向高边坡开挖与偏压隧洞掘进、支护)为例,在描述出口边坡地形、地貌及工程地质条件的基础上,建立了相应的三维数值计算模型。即基于弹塑性理论考虑岩土体的时效特性,在FLAC3D平台上进行了二次开发与数值计算。分析结果表明,围岩和管棚的变形量较小,出口段管棚支护方案基本能维持围岩稳定,但顺向边坡的变形量较大,需预防边坡表层发生破坏;紧邻放空洞未出现贯通塑性屈服区,但管棚两侧应力分布不对称、内侧拱脚应力较大,可能会造成局部失稳,进而对原有工程开挖、支护方案进行了合理优化,可为类似边坡、洞室的施工建设提供安全判据和参考。
[Abstract]:In view of the problems such as the uncertainty of geotechnical parameters, special geological conditions and complex working conditions in the downstream high slope, partial pressure tunnel engineering, and so on, taking the outlet of #1 spillway tunnel of Shentianhe Reservoir extension project as an example, the excavation of the outlet of the #1 flood discharge tunnel and the excavation and support of the eccentric pressure tunnel are taken as an example.On the basis of describing the topographic, geomorphological and engineering geological conditions of the exit slope, the corresponding three-dimensional numerical calculation model is established.Based on the elastic-plastic theory, the secondary development and numerical calculation are carried out on the FLAC3D platform.The results show that the deformation of surrounding rock and pipe shed is small, and the support scheme of pipe shed in outlet section can basically maintain the stability of surrounding rock, but the deformation amount of the forward slope is large, so it is necessary to prevent the failure of the surface layer of the slope.There is no through plastic yield zone in the adjacent cavities, but the stress distribution on both sides of the pipe shed is asymmetrical and the stress on the inner arch foot is large, which may lead to local instability. The excavation and support scheme of the original project is optimized reasonably, which can be used as a similar slope.The construction of cavern provides safety criterion and reference.
【作者单位】：长沙理工大学水利工程学院;
【基金】：国家自然科学基金项目(51279019)
【分类号】：TV223;TV554

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