| With the implementation of the western region development strategy in our country,the great depth tunnel always need to be constructed due to the need of infrastructure construction,Many regions contain the geothermal resources in china,high temperature has a serious influence on construction quality,in order to provide theoretical guidance to practical engineering construction,this paper combined the high geothermal great depth diversion tunnel stability analysis and construction technology research project of qirehataer hydropower station with indoor test and field investigation,by adopting the combination of CT ? XRD ? SEM technology to study the adhesive strength of surrounding rock-support structure under different hot and humidity environments and reveal the surrounding rock-support structure interface micro morphology ? phase changes and the performance degradation mechanism at the same time using the discrete element method build surrounding rock-support structure adhesive constitutive model,the surrounding rock-support structure interface layer crack initiation,distribution and development rule were explored finally.The main research results are as follows:(1)Based on the hot and humidity environment qirehataer hydropower station diversion tunnel,the rock-concrete temperature-humidity control system was built,the shotcrete-surrounding rock temperature and humidity control system can better simulate the environment that hot and humidity about high geothermal diversion tunnel.(2)The temperature ? humidity and age have an serious influence for the adhesive strength of surrounding rock-support structure,when the humidity become more decreased,the 75 ? was the critical temperature that caused the reason the adhesive strength of shotcrete pour the shrinkage,but with the humidity increase the critical temperature that caused the reason the adhesive strength of shotcrete pour the shrinkage will also rise.(3)Along with the temperature increase the distribution of the holes present irregularity,internal hole area is gradually increasing along the axial direction and humidity environment is conducive to the hydration reaction of cement paste,the C-S-H gel own high crystallinity,promotes the development of adhesive strength,butthe low humidity environment is not conducive to the development of the adhesive strength.(4)The surround rock-support structure numerical model was built based on discrete element method and considering the particle size effect,it can be better real reflection the interface layer crack initiation ? extend ? cut-through and the macro damage process. |
PDF Full Text Request