Application of tunnel monitoring measurement information feedback in surrounding rock dynamic classification
The subsurface engineering of highway (railway) tunnels etc are concealed work, because of the effects of environment and outlay, it is impossible to prospect accurately, and rock and soil is complex and multivariable, thus master project planning and scheduling document and lining structural design, that is preliminary design, are blindfold. Accordingly NATM has been widely used in the underground works, through the site monitoring and measurement alters design, adjusts supporting parameters and construction technique, so insure the tunnel construction's safety. The key of monitoring measurement Information feedback design is determination the level of the surrounding rock, which was judged mainly based on engineering experience in the past. According to the monitoring and measurement information of perimeteral convergence, surrounding rock pressure and internal force of parapet grille reinforcement in some highway tunnel, through statistical regression analysis on masses of monitoring data, acquires the statistical average of monitoring data when surrounding rock go to stable condition, which can be used for the basis of surrounding rock dynamic classification; adopt entropy method; give the calculation procedures of surrounding rock dynamic classification; according to the monitoring results of some tunnel, give a example to show the quantitative method of surrounding rock classification is feasible and accurate; which provides a new meaning and theoretical basis for the NATM.