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。
Aiming at the problems about the uncertainty of geotechnical parameters,the complexity of geological condition and the complicated working conditions,a large 3-D numerical calculation model was built based on the descriptions of the project＇s shape,geomorphology and geological conditions,which was taken the Centianhe Reservoir expansion project（the excavation and support in the bedding high slope and bias tunnel engineering of#1flood discharge tunnel）as an example.And the eastoplasti＇s time-dependent load was stimulated on the basis of eastoplastic theory.Then,an secondary development was carried out on the FLAC3 Dplatform.The simulation results demonstrate that the deformation of surrounding rock and pipe roof reinforcement was small,the pipe roof reinforcement and surrounding rock can be keep stability basically while the consequent slope needs to be protected from damage because of the deformation of consequent slope was large;the plastic yield zones in the adjacent empty tunnel were not run-through;however,the asymmetry distribution of stresses on both sides of the pipe roof reinforcement and the large stress of inside arch may cause damage in some areas.Therefore,some appropriate improved schemes on the original project plan were put forward,which could provide some safety criterion and references for the similar projects.
出处
《水电能源科学》
北大核心
2016年第4期107-110,138,共5页
Water Resources and Power
基金
国家自然科学基金项目(51279019)
关键词
涔天河水利枢纽
顺向边坡
偏压隧洞
洞挖安全稳定分析
管棚预支护
Centianhe Hydropower project
consequent slope
bias tunnel
safe and stability analysis
pipe roof reinforcement
