Study On Dynamic Identification Of Surrounding Rocks' Mechanical Characteristics In Percussive Rotary Drilling With Holes

With the rapid development of China's economy,a series of construction activities such as mineral exploitation and urban construction are increasing.Drilling activities in engineering projects have also increased.In the process of drilling,because of the interaction between drilling rig and rock body,the drilling speed,cylinder pressure and other drilling parameters are changed during drilling,thus producing data while drilling.The data while drilling contains important information of surrounding rock mechanics parameters.Due to the lack of analysis and Research on data while drilling,these information can not be collected and analyzed in time,resulting in a huge waste of information resources.It is particularly important to master the data acquisition and analysis method while drilling under the background that more and more attention is paid to safe and efficient production in today's engineering construction activities.In this paper,the principle of orthogonal design is used to study the law of rock similar material ratio test,and drilling rock samples with different strength are allocated.In the percussive rotary drilling test,the variation of drilling parameters with rock mass strength is analyzed by multiple factors.By analyzing the relative change rate of drilling parameters and the responsiveness to the change of rock mass strength,the matching of drilling parameters under different strength ranges is judged.Secondly,several drilling parameters are linked,and data regression fitting is carried out to analyze the law of the variation of drilling parameters with rock mass strength.Using ANSYS/LS-DYNA numerical simulation,the law of indoor drilling test is revealed.The main work of this paper includes the following aspects:(1)The proportioning test of rock similar materials was carried out,and the influence rule of test factors on rock similar materials was obtained.Based on the orthogonal design principle,a multi-level and multi-factor test scheme was designed,and the factors affecting the strength of rock similar materials were comprehensively analyzed.Configuration of impact specimens for indoor drilling tests.(2)The indoor percussive rotary drilling test was carried out,and the variation of drilling parameters with rock mass strength was analyzed.Real-time drilling data obtained from impact rotation test are used to analyze the influence of drilling factors on rock mass strength.Fitting and analyzing the test data,the functional relationship between rock mass strength and drilling factors is obtained.The relationship between the specific work of breaking and drilling and the strength of rock mass is obtained.(3)The sensitivity of drilling parameters to the change of rock mass strength is analyzed.Based on the analysis results of drilling tests,the relative variation rate of drilling factors and the responsiveness to rock mass strength change are calculated,and the optimal drilling parameters for identifying rock mass strength under different rock mass strength ranges are analyzed.Multivariate linear fitting and non-linear fitting of multi-parameters are carried out,which improves the reliability of real-time identification of surrounding rock mechanical properties by data while drilling.(4)Based on the results of numerical simulation,the variation of percussion drilling parameters with rock mass is revealed.Based on ANSYS/LS-DYNA explicit simulation and analysis software,the percussive rotary drilling process is simulated.By changing the strength parameters of impact rock mass,the regularity of drilling parameters varying with the strength of rock samples is revealed.