Back Analysis Of Surrounding Rock Rheological Parameters And Research On Support Optimizationin Deep Coal Roadway

With the increasing of mining depth, the depth of mines have exceeded one thousand meters, rock shows some rheological property. Under the action of high ground stress, the phenomenon of ground pressure and deformation are tremendous in soft rock roadways, Support problem of soft rock roadways that are deep-depth and high geo-stress are serious. Therefore, the thing that deformation and failure mechanism of deep-depth soft rock roadways is researched is important significative to control the stability of surrounding rock. Based on characteristic that surrounding rock of deep-depth roadways of Zhao zhuang mine is serious broken and rheological theory, rock rheological parameters which accord with the actual engineering are got by the back analysis combined with the theoretical analysis, the field observations and the numerical simulation. And on this basis the optimizing supporting scheme of deep-depth soft rock roadways is designed. And the study results are shown as following:(1) Based on linear elastic theory, the analytical solutions of elastic theory of roadway deformation are developed by two computing models. And on this basis the analytical solutions of viscoelasticity theory of roadway deformation is developed by theoretical derivation combined with Burgers constitutive model to prepare for back analysis.(2) As for the deficiency of basic BP neural network algorithm that error function is easy to fall into local minimum values not to the global minimum values, the accuracy values of the algorithm is difficult to obtain in the process of calculation, in order to get higher accuracy intelligent back analysis algorithm, BP neural network algorithm is Corrected by PSO algorithm.(3) At the situation that the field monitoring data is brought into the revised back analysis algorithm, at the result, the parameters values of Burgers constitutive model which accord with the actual engineering are got by back analysis algorithm. At the same time, With the change of time, inherent mechanism that roadway deformation is effected by changes in the different parameters of Burgers constitutive model is researched through computer calculations.(4) On the basis of surrounding rock mechanics parameters of Burgers creep model are obtained. At the situation of different mechanical parameters, grouting time and the thickness of grouting reinforced region, the change law of grouting supporting effect is researched. After analyzing, it is difficult to get the most reasonable supporting effect through raising only one or several parameters values of grouting. In order to get the most reasonable support parameters values, it is necessary to consider comprehensivly that every grouting parameter’s role in roadway deformation(5) At the situation of different mechanical parameters, grouting time and the thickness of grouting reinforced region, grouting supporting effect is researched by the method of grey correlative analysis, and the most reasonable parameters values of the whole section secondary grouting support are got, on this basis the optimizing supporting scheme of secondary grouting support is designed.