论文部分内容阅读
对地下洞室的长期观测和量测都表明,许多在成洞之初呈现稳定的岩体,由于变形随着时间推移而不断发展,经过一段时间之后,洞体可能失稳或坍塌破坏,特别是大型地下洞室,地质条件复杂、开挖时间长、扰动大,其长期稳定性更值得关注。向家坝地下厂房为一超大型地下洞室,开挖跨度在国内外已建、在建和拟建的水电站中居第一,其跨度和规模均居世界前列。洞室围岩地质条件复杂,岩性较差,有不稳定块体,地下水较为丰富,岩石透水性较好,且夹杂有多条软弱夹层,对地下厂房长期运行不利。基于此,通过试验得到了地下厂房围岩的长期强度;结合实际工程中常用的变形和流变速率,提出了洞室最佳支护时间、长期稳定流变时间、最大流变变形的判据;对洞室支护措施进行了模拟,对其支护效果进行了评价。经过总结分析,得到了对工程有指导性的结论。
Long-term observations and measurements of underground caverns indicate that many of the rock masses that appear stable at the beginning of the cavern, as the deformation evolves over time, may collapse or collapse after some time, in particular It is a large underground cavern with complicated geological conditions, long excavation time and large disturbance. Its long-term stability deserves more attention. Xiangjiaba underground workshop is a large-scale underground cavern. The excavation span has been built both at home and abroad. It ranks first in the hydropower stations under construction and in construction. Its span and scale rank the forefront in the world. Surrounding rock caverns are characterized by complex geological conditions, poor lithology, unstable blocks, abundant groundwater, good permeability of rocks, and mixed with a number of weak interbeds, which are unfavorable to the long-term operation of the underground powerhouse. Based on this, the long-term strength of the surrounding rock mass of underground powerhouse is obtained through experiments. According to the deformation and rheological rate commonly used in practical engineering, the criterion of optimal support time, long-term stable rheological time and maximum rheological deformation The support measures of cavern are simulated and the support effect is evaluated. After summarizing and analyzing, we got the guiding conclusion to the project.