复杂岩石块体识别的单元重构–聚合方法

为解决工程岩体开挖中含有复杂开挖边界时的块体识别问题，提出岩石块体识别的单元重构–聚合方法。首先，引入成熟的网格划分技术，通过建立网格模型(如有限元模型)，实现对复杂开挖边界的精确模拟；其次，采用基于单元重构技术的结构面建模方法，将分布于岩体内的结构面建入网格模型；然后，提出基于单元聚合技术的块体构建方法和考虑有限性结构面时的单元组处理方法；最终可实现基于网格模型的复杂岩石块体识别。该方法识别所得的块体系统基于网格模型，块体的所有特征信息均可通过模型的单元和节点提取，块体的可视化也可在既有网格模型图形显示平台上实现。算例验证表明，当将结构面分别考虑为无限延伸和有限延展时，该方法的块体识别和稳定分析成果均与通用块体分析软件的结果一致。进一步将该方法应用于水电站大型地下洞室群的块体识别，可证明其应用于复杂岩石块体识别的有效性和优越性。因此，该方法是一种能够考虑复杂工程岩体开挖边界的岩石块体识别的新方法，其实现过程独立于基于拓扑原理的传统块体识别思路，为块体稳定分析提供了新的实现途径。

IDENTIFICATION METHOD OF COMPLEX ROCK BLOCKS USING ELEMENT RECONSTRUCTION AND AGGREGATION TECHNIQUE

In order to cope with the issue of block identification during the construction process of engineering rock masses containing complex excavation boundaries,a new method for identification of rock blocks is presented based on element reconstruction and aggregation technique.Firstly,the sophisticated mesh gridding technique is employed to establish meshes(e.g.finite element mesh),thus realizing the accurate simulation of complex excavation boundaries.Then,the modeling method for geological discontinuities based on element reconstruction is employed;thus inserting the geological discontinuities which are widely distributed in rock masses into the meshes.Afterwards,the block construction method based on element aggregation technique and handling procedures for finite structural planes are presented;thus realizing the identification of complex rock blocks based on meshes finally.As the identified block system is defined on meshes,all specific information of block system can be obtained through the elements and nodes of meshes.The visualization of blocks can be also realized using mesh graphic display platform.The validation examples indicate that when the structural planes are considered either infinite or finite,the block identification and corresponding stability analysis results are identical to those derived from common software for block analysis.The presented method is further illustrated with its application to a large-scale hydropower underground cavern complex;and its effectiveness and superiority can be verified.Therefore,the presented method is determined to be a new approach for block analysis,in which complex excavation of engineering rock mass can be considered.Its implementing procedures are totally independent from the traditional topology-based block identification algorithms,thus providing a new tool for block stability analysis.