TBM Advanced Drilling Test And Study On Rapid Evaluation System Of Construction Characteristics Of Surrounding Rock

This paper focuses on two aspects of TBM,the first aspect,advanced drilling engineering mechanics test.Two field trials were conducted:both indirect tests(drilling-hole test,single hole acoustic wave test)and direct tests(point loading test,uniaxial compressive strength test)were included,obtaining a large amount of geological information and rock mechanics information,establishing the relationship between the parameters of drilling process and the quality of rock mass,and the uniaxial compressive strength,size and underground distribution of the rock mass in front of the face can be verified quickly,effectively and quantitatively as well as the production,extension,flatness and thickness of the interface cross section and the physical and mechanical properties of the filling material.In the second aspect,the rapid evaluation system of construction characteristics of surrounding rock is studied.First,the TBM tunneling test is simulated by the granite drilling test.The parameters such as rotating speed,torque,propulsion and drilling displacement are recorded through the Drilling Process Monitoring system,and then the multivariate function fitting is carried out by using the parameters.At the same time in order to seek a parameter to replace drilling speed to evaluate the quality of rock mass,the concept of drilling specific energy is introduced,resulting well.And then we return to the TBM tunneling test,based on the massive field excavation data and a large number of engineering geological information,the paper also analyzes the parameters of the rock,we choose the rotating speed,cutter torque,propulsion,propulsion displacement for multivariate function fitting analysis imitating granite drilling test.Then the concept of Tunneling Specific Energy is introduced,and then compared with the tunneling speed under the condition of different strength grading of surrounding rock.The main conclusions are the following two points:the Drilling Process Monitoring system(DPM)can record the rotating speed,pressure,torque and drilling displacement through the corresponding sensor while drilling,and drilling speed can reflect the strength characteristics of the rockmass.For the same kind of rock,we can not just rely on the drilling speed to carry out the classification of the surrounding rock,instead,we should consider the additive effect of pressure,speed and other parameters.Tunneling Specific Energy has smaller volatility,less error(about 10%)and better correlation with standard for classification of rock mass than tunneling speed,and it can be used as the criterion of rock mass quality evaluation.The weaker the strength of the surrounding rock,the greater the contribution of torque power to the tunneling speed,indicating that the tunneling speed will be effectively picked up when we increase torque in the case of weaker rock and when we increase thrust in the case of stronger rock.