混凝土力学时空特性对衬砌支护设计影响研究

Study on the Influence of Spatiotemporal Characteristics of Concrete Mechanics on Penstock Shaft Lining Design

竖井支护设计对围岩稳定和施工安全具有重要意义,水利水电工程中采用正井法开挖引水竖井的工程案例较少。根据正井法施工特点,确定开挖、初衬以及拆模等工序需要的具体时间,考虑混凝土力学参数的时效特征,并结合所在区域的地质条件、岩体力学参数以及开挖进尺,对初衬设计厚度、强度以及拆模时间等进行了研究,形成了一套基于正井法施工,考虑衬砌混凝土力学参数时空特征条件下的衬砌设计方法。实践表明,考虑混凝土力学参数时空特征条件下的支护设计更加合理,具有一定经济和社会效益。

Shaft support design is of great significance for surrounding rock stability and construction safety.In the field of hydropower engineering,there are few engineering cases in which the penstock shaft is excavated and supported by the downward drilling method.According to the construction characteristics of downward driving method,the specific times required for the excavation,primary concrete lining installing and form removal process are firstly determined.Then considering the aging characteristics of concrete mechanical parameters,the geological conditions,the rock mechanics parameters and the excavation footage,the designed thickness and strength of primary concrete lining and the time for form removing are studied.Finally,the lining design method based on downward driving method and considering the aging characteristics of concrete lining is formed.The practice shows that the design of lining support considering the spatiotemporal characteristics of concrete mechanical parameters is more reasonable and has certain economic and social benefits.