Research On Cutting Strength Characteristics Of Rock And Rotary Cutting Penetration Test For Mechanical Parameters Of Rock Mass

In geotechnical engineering,how to obtain mechanical parameters of rock mass as the key research subject for geotechnical engineering is always the research emphasis.Based on this research objective,rotary cutting penetration technology tries to bring new idea and method for quick getting mechanical parameters of rock mass.Based on new rotary cutting penetration,the theoretical relationship between rock mechanical parameters with operation parameters(drilling speed and revolving speed)and response parameters(bit pressure and torque)have been studied.Under different operation parameters,the rotary cutting penetration tests of angle piece drill and twist drill and hollow drill have been done,also the mechanical parameters tests of different samples have been done.The laws of rock cutting property and relationships between rock cutting property and rotary cutting penetration test.The core control system of spot rotary cutting penetration instrument includes expert system and neural network model has been established.The development of XCY-1 type rotary cutting penetration instrument has been finished after conducting a detailed technical and equipment design,and also the first test results have been finished.The main contents and innovation points are as follows:(1)The relationship between rock mechanical parameters with operation parameters and response parameters of rotary cutting penetration test have been revealed after the process of rock indentation and cutting has been dissected.Based on two aspects of the mechanical balance and energy conversion,the theoretical formulas of elastic modulus and compressive strength and internal friction angle and coheision have been obtained.Then the test results show that theoretical results have engineering application value.(2)Combined with rotary cutting penetration test results and related data,rotary cutting fracture zone had been defined,also the cutting strength index and cutting strength have been put forward.The evolution models of bit pressure and torque have been established.Beginning from the influence laws between operation parameters and response parameters of rotary cutting penetration test,the relationships between cutting thickness and ration with feed force and cutting force have been obtained,also the relationships between rock cutting strength property and response parameters of rotary cutting penetration test.The increase of drilling speed makes the cutting strength index decline,and the increase of revolving speed makes the cutting strength index increase.Operation parameters of rotary cutting penetration test is independent of rock cutting strength,and cutting strength caused by rock engineering effort properties is related to mechanical parameters under the same drill.(3)Based on the difference research for the drill cutting and sample strength of rotary cutting penetration technology,the relationships between rock mechanical parameters and ration with feed force and cutting force have been obtained,also the rotary cutting penetration test response laws caused by drill cutting and sample strength differences have been acquired.With the improvement of sample material strength,cutting strength index and cutting strength of angel piece drill and twist drill are both contiguous and less than hollow drill.But the experimental fitting rules between cutting strength index and cutting strength of angel piece drill and hollow drill are both contiguous and different from twist drill.(4)A detailed analysis of rock mass classification and classification method had been done.Based on the rotary cutting penetration technology objective,the qualitative and quantitative evaluation standard of new rock mass classification have been put forward for the first time using quantitative evaluation method and qualitative factor description method.(5)Based on the rotary cutting penetration technology,the inference rules and classification bases of rock classification expert system have been established,and the results have been modified by psychological factors.The neural network predictive model of rock mechanical parameters have been written after the comparative analyses of BP neural network and GRNN neural network and RBF Neural network had been done.The rapid intelligent integration system of rotary cutting penetration technology has been developed.Intelligent calculation for obtaining mechanical parameters of rock mass and rock mass quality levels have been achieved in the construction site.The rotary cutting penetration technology that has been verified after entering SANHEKOU water conservancy hub for testing,and application of the scene has a good prospect of engineering application.