基于数值流形方法的地下厂房顶拱喷混凝土开裂成因机制分析  

Analysis of Cracking Mechanism of Shotcrete in Underground Powerhouse Crown based on Numerical Manifold Method

作　　者：吕风英 任韬哲 何军 LV Fengying;REN Taozhe;HE Jun(Pumped-Storage Technological&Economic Research Institute,State Grid Xinyuan Company Ltd.,Beijing 100761,China;Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Yangtze River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]国网新源控股有限公司抽水蓄能技术经济研究院,北京市100761 [2]长江水利委员会长江科学院水利部岩土力学与工程重点试验室,湖北省武汉市430010

出　　处：《水电与抽水蓄能》2022年第5期37-42,共6页Hydropower and Pumped Storage

摘　　要：喷混凝土是地下洞室围岩的重要初期支护结构之一。针对丰宁抽水蓄能电站地下洞室的顶拱喷混凝土开裂问题,本文在围岩地质条件和监测数据分析的基础上,采用适于岩石不连续变形问题分析的数值流形方法,对喷混凝土的开裂成因机制进行了研究。首先,基于地质条件和监测数据分析,发现地下洞室顶拱喷混凝土开裂较严重的区域,主要集中在表层围岩变形较大区域,并从荷载效应和围岩变形特性角度,定性分析了喷混凝土开裂原因。其次,在数值流形法中引入节理单元的本构关系,实现了连续体的粘结-开裂过程的模拟。最后,将所提数值方法应用于顶拱喷混凝土开裂的定量分析。计算结果表明,围岩不连续变形将导致喷混凝土承担的弯曲荷载增大,并在荷载值达到喷混凝土的承载极限时发生开裂,进而揭示了岩体结构控制型地下洞室的顶拱喷混凝土层的开裂机理。Shotcrete is one of the important primary support structures for the surrounding rock of underground caverns.Aiming at the cracking phenomena of shotcrete in the top arch of underground caverns of Fengning Pumped Storage Power Station and based on the analysis of geological conditions of surrounding rock and monitoring data,the cracking mechanism of shotcrete is studied by using the numerical manifold method suitable for the analysis of discontinuous deformation of rock.Firstly,based on the analysis of geological conditions and monitoring data,it is found that the serious cracking areas of shotcrete in the crown of underground cavern are mainly concentrated in the areas with large deformation of surface surrounding rock,and the cracking causes of shotcrete are qualitatively analyzed from the perspective of load effect and deformation characteristics of surrounding rock.Secondly,the constitutive relationship of joint elements is introduced into the numerical manifold method to simulate the bond-cracking process of the continuum.Finally,the proposed numerical method is applied to the quantitative analysis of the cracks in the top arch shotcrete.The calculation results show that the discontinuous deformation of the surrounding rock will lead to the increase of the bending load by the shotcrete,and the shotcrete will crack when the load value reaches the bearing limit of the shotcrete.Thus,the cracking mechanism of the shotcrete layer in the top arch of the underground cavern controlled by rock mass structure is revealed.

关 键 词：地下洞室 喷混凝土 开裂 机制分析 数值流形法 

分 类 号：TV543.6[水利工程—水利水电工程]