三峡工程永久船闸高边坡岩体变形特征与机理分析

三峡工程船闸高边坡变形监测资料表明,岩体变形主要受开挖卸荷影响,边坡岩体卸荷松邓特征明显,具有分带性。微风化新鲜岩体变形主要是沿结构面张开实现的,从而引起岩面找平混凝土或喷护混凝土开裂。岩体变形大小与变化过程还与地质条件、施工爆破、锚固等因素有关。     

三峡工程永久船闸高边坡岩体力学特性研究

针对三峡工程永久船闸高边坡的特点，提出了随国坡开挖形成边坡岩体的质量指标，变形模量，强度等的劣很 估算方法。指出了通常人们研究岩石边坡时，采用不变的岩体参数进行数值分析，工程设计等，是不能反映这种情况的。     

三峡工程永久船闸岩体高边坡锚固方案优化研究

三峡工程永久船闸高边坡岩体卸荷非线性力学分析的基础上，分总体锚固方案及具体锚固措施两个层次研究了边坡锚固问题，总体四个方案的研究表明边坡下部直墙重点锚固是最优方案；具体措施锚固方案研究成果表明，长大锚洞方案最优，其他方案锚固力似有不足，可能影响边坡的长期稳定。     

三峡临时船闸及升船机高边坡岩体变形特征

以现场实测资料为依据 ,分析了三峡临时船闸及升船机高边坡岩体变形特征及其形成机制 ,认为岩体变形形式和机制与岩体地质结构面类型及其在边坡中的分布密切相关。并且 ,即使是在坚硬的花岗岩边坡中 ,岩体流变变形是存在的 ,对边坡稳定具有重要的工程意义     

三峡永久船闸高边坡施工期岩体应力变化监测

在三峡永久船闸高边坡施工过程中,岩体因开挖卸荷而导致的应力变化被列为施工 监测内容之一。采用的应力变化监测传感器主要有Ｙｏｋｅ应力计、电容式应力计及压磁式应力计仪器。截止１９９８年２月,部分仪器已有两年半的实测资料。     

三峡永久船闸高边坡锚索预应力状态监测分析

三峡永久船闸高边坡使用了250束1000kN和3873束3000kN的预应力锚索进行加固,并安装了113台锚索测力计对锚索的受力状态进行长期监测,在使用锚索的数量及安测力计台数上均属世界少有。在对锚索测力计监测资料系统整理和分析的基础上,重点分析了高边坡锚索的受力状态、加固效果及预应力损失,为船闸高坡稳定安全状态的判别提供依据,并为今后其他工程提供可资借鉴的实际应用资料。     

三峡工程永久船闸中隔墩岩体变形全过程测试研究

针对三峡永久船闸勘探设计阶段已有勘探平洞的布置特点,利用船闸二闸室中隔墩中部的8#平洞主洞,在船闸开挖初期布置多点位移计测孔,实现了中隔墩岩体开挖过程中近4a的全过程监测。根据变形观测设施观测结果,对中隔墩岩体随船闸开挖的变形过程以及岩体的变形特征进行了分析,并将观测结果与数值计算结果进行了比较。最后,对中隔墩岩体的稳定性问题进行了讨论。     

三峡永久船闸高边坡安全监测

在深入分析永久船闸高边坡安全问题的基础上，提出了安全监测设计的基本原则；针对三峡船闸高边坡中的稳定性问题，提出了具体的监测要求：最后给出了具体的监测部位(断面)及监测项目和仪器的优化布置方案。实践表明，该方案是可行的，系统提供的监测数据能相互协调，互相印证。     

三峡船闸高边坡裂隙岩体渗流监测成果分析

三峡船闸是三峡工程的主要工程之一。闸室区边坡高度一般为70～120m,最高约160m,地下水是影响岩体高边坡稳定的重要因素之一。介绍了船闸高边坡施工期地下水渗流监测的布置和实施情况,根据将近3 a的实际监测成果,分析了施工期船闸高边坡地表降雨、排水、水质、排水硐渗流渗压的变化规律和影响因素;监测成果分析认为,施工期船闸南北边坡地下水位均低于设计水位,与长江科学院计算成果基本一致,随着二期工程的实施,地下水位将随之缓慢降低,说明设计最后选定的渗控方案是基本合理的。     

三峡工程永久船闸陡高边坡各向异性卸荷岩体力学研究

岩体工程具有加载和卸荷两类不同性质的力学状态,在此力学状态各异的情况下,节理岩体的力学特性有本质的区别。岩体高边坡工程的力学状态主要为卸荷。在三峡工程永久船闸高边坡的研究中,作者提出了“各向异性卸荷岩体力学的新概念”,得出了与目前常规岩体力学研究不同的结论。该研究成果已被多项边坡工程和地下工程实例所验证。以前应用该理论对三峡永久船闸陡高边坡的研究成果,也日益为监测资料所验证。     

Deformation of the central pier of the permanent shiplock, Three Gorges Project, China: an analysis case study

The central pier (CP) is one of the key structures of the permanent shiplock in the Three Gorges Project on the Yangtze River, China. This paper deals with the study of the rock mass deformation of the CP of the second shiplock under various operation conditions. Numerical simulations using the 2-D distinct-element method and 3-D finite-element method are applied to analyze the rock mass deformation. Also, time-series analysis and gray system theory are used to predict the trends of rock displacements based on in situ measured data. The results can be summarized as follows: (1) the main deformation of the rock mass in the CP occurs after excavation completion, while the shiplock is in operation, the dominant displacements mainly occurring on both sides of the northern chamber, developing generally towards the chamber; (2) the horizontal displacement varies with the process of excavation, and is in a steady state after excavation, and during operation of the shiplock the displacement is slightly decreased; (3) the horizontal displacement parallel to the axial line of the shiplock occurs downstream; and (4) the vertical displacement occurs during excavation, and then subsidence with various values takes place in different parts of the CP for different operation conditions.     

Key issues in rock mechanics of the Three Gorges Project in China

The Three Gorges Project is one of the essential key projects for flood controlling and water resources regulation in the Yangtze River.The project includes a river-crossing dam,underground powerhouses,and navigation structures.Because of the huge size and complicated construction technologies,the project faced a series of challenging engineering issues.In terms of rock mechanics,there are many key technical issues,including the sliding resistance and stability of the dam section along the foundations of powerhouses No.1-5,the slope stability of the double-line five-stage shiplock,excavation of large-scale underground powerhouses,and curtain grouting under the dam.With decades of scientific research and 16 years of practical construction experiences and reservoir operations,these key technical issues in construction of the Three Gorges Project are successfully resolved,which will attribute to the development of hydropower technology.On the basis of the monitoring data during construction and normal operation periods of the Three Gorges Project,this paper presents a systematic analysis of these key rock mechanical issues in terms of behaviors,solutions,dynamic controlling,monitoring arrangement and integrated assessment.     

高边坡变形监测系统设计

根据高边坡的具体特点,从监测方案的基本原则、监测项目、监测仪器布置原则、观测精度要求等方面出发,总结出较为合理的监测方案,结合工程实际提出了行之有效的测量方法、措施.     

Blockiness level of rock mass around underground powerhouse of Three Gorges Project

A fundamental question in rock mechanics is whether a rock mass is a continuum or an assemblage of isolated blocks. Some models have treated rock masses as continuums and others, as isolated blocks. Most rock masses are neither continuums nor isolated blocks, but something between them. This study presents a new concept of blockiness to measure a rock’s level of being an assemblage of isolated blocks. Thirty-five types of theoretical fractured rock mass structural models are established by considering fracture classifications. For each structure, rock blocks are identified using the GeneralBlock program, and the blockiness is investigated. The blockiness of the surrounding rock mass of the underground powerhouse in the Three Gorges Project is systematically investigated. Based on measurements of fractures obtained from a field survey, a discrete fracture network model is established by an inverse method for identifying and analyzing rock blocks. The results show that the blockiness of the surrounding rock mass of the underground powerhouse is only 4‰; the total rock mass shows very good quality and stability; the number of blocks in the rock mass is quite small; therefore, the volume of isolated blocks only accounts for a very small proportion of the total rock volume; and the rock mass can be considered a continuum. The excavation process of the underground powerhouse in the Three Gorges Project verified these conclusions; only a few blocks are formed by fractures in the rock mass of the underground powerhouse. The calculation results for the 35 models show that the blockiness of the rock mass having medium persistence and very wide spacing is very low. The structure of the rock mass around the underground powerhouse is of this type. Its blockiness agrees with the model calculation results. Therefore, the calculation results for the 35 models are useful in predicting the stability of rock masses having different persistence and spacing, and they could serve as a reference for quantifying the quality of rock masses in other projects. And, in this study, the concept of the blockiness level of rock mass was determined by one example only, and more studies would be concluded for other projects to validate this concept in future study.     

块体理论在三峡工程中的应用

在介绍裂隙随机块体和定位块体研究方法的基础上,提出一种块体运动模式的矢量判别方法,应用块体理论对三峡地下厂房围岩裂隙随机块体及大型断层定位块体和三峡船闸高边坡块体进行分析,并对加固后块体的稳定性进行研究。     

三峡永久船闸高边坡开挖及加固支护设计

永久船闸高边坡是三峡工程的重要建筑物，也是船闸结构的重要组成部分，规模巨大，技术复杂。确定合理的设计原则，选定合适的安全度标准，拟定合理的开挖形态和进行恰当的加固支护，制定合理的开挖与加固施工程序，确保边坡稳定和变形满足结构及运行要求是船闸高边坡设计中研究的主要问题。本结合围绕高边坡设计所进行的大量试验及分析研究成果，系统介绍了船闸高边坡的基本设计思想及开挖与加固支护基本设计方案。     

岩体预应力锚索在三峡工程中的应用

三峡工程应用有大量的岩体预应力锚索，本详细介绍了三峡锚索的选型、作用、应用中出现的问题及对策等，并就岩锚的施工机具及新型防腐结构问题提出了作的观点和建议。     

施工期岩体等效渗透张量求解法———以三峡工程永久船闸边坡为例

根据对岩体结构面及地下水流渗流量的调查和观测,概化出渗透结构面及其分组,利用极值控制法求出渗透结构面的渗透系数,进而求出岩体的初始渗透张量;基于岩体的初始渗透张量及现场观测的渗流量,利用有限元法求解岩体等效渗透张量。该方法能够比较客观地确定施工期岩体的等效渗透张量。