高混凝土坝坝基开挖工程的岩体稳定性问题研究

A STUDY ON THE ROCKMASS STABILITY OF DAM FOUNDATION DURING THE EXCAVATION OF BEDROCK OF HIGH CONCRETE DAMS

建立了3种不同的力学模型,即:1.粘弹塑性模型,2.脆性断裂模型,3.组合模型。对坝基岩体开挖稳定性问题进行了分析计算,探讨了坝基建基面与时间因素有关的位移、应力、屈服破坏的动态过程。据此可在定量分析基础上确立风化裂隙岩体与应力集中区岩体的可利用标准,使确立的建基面更符合生产实际。

On the basis of the two principal geological factors—rockmass structure and ground stress environment, three mechanical models are established. They are: 1) visco-elastic plastic model, 2) fracture model, and 3) combined model. Rockmass mechanics is applied in the analysis of the rockmass stability of the dam foundation and the dynamic process of displacements, stresses, yield destruction with the construction base level of dam foundation. Based on the quantitative analysis, a criterion is established for the use of the rockmass in which there are weathering fissures and stress concentration. It makes the established construction base level of the dam foundation more consistent with reality.The design theory and method proposed in this paper have been employed in the Ertan project. The calcution method based on ground stress has proved reliable and can be applicable to other engineering projects.