深埋隧洞中高水压对致密围岩变形的影响程度

The Influence of Underground Water on Surrounding Rock Deformation in the Deep Rock Engineering

在深埋高围压、高水压岩石工程中,合理分析高水压对围岩的影响程度,对控制工程成本具有重要意义。为了研究高水压力对围岩稳定的影响程度,通过分析适用于岩石中的Biot有效应力原理,本文在弹性条件下推导出用常见岩石参数表示的Biot系数公式,分析总结出Biot系数不仅和孔隙率有关,随孔隙率减小而非线性减小,而且还跟岩石泊松比或者说岩性有关,其值大于孔隙率。并且提出了在特定围压和水压下,孔隙率小于某个界限值时可以忽略水压力影响,并给出了界限值的求解方法。最后通过锦屏二期水电站引水隧洞实例分析,验证了论文观点的正确性。

In rock project with high confining pressure and high water pressure, reasonable analysis of the influ- ence of high water pressure on the rock deformation plays an important role in the control of project cost. In order to study the degree of influence, the new Biot coefficient formula with the common rock parameters is derived under the elastic condition through analyzing the Blot principle of effective stress applied in rock, We can know that Blot coeffi- cient is not only related to the porosity of rock, but also with the rock Poisson ratio or Litho logy, The Biot coefficient nonlinearly decreases with the decrease of porosity, and its value is greater than the porosity. It is proposed that in particular confining pressure and water pressure, the water pressure can be ignored when the porosity is less than a certain threshold value, and the method of getting the threshold value has also been provided. Finally, we test and verify the correctness of the viewpoint in this paper through the analysis of Jinping II Hydropower Station.