Research On In-situ Parameter Acquisition Technique Of Hard Soil Based On Rotary Touching

With the development of China’s infrastructure construction,profound changes are taking place in the field of engineering construction,and the engineering construction environment is becoming increasingly complex,the construction is extremely difficult,and the preliminary survey work even more difficult.With the implementation of the dual carbon strategy,a large number of pumped storage power station projects have been accelerated,and the original survey work in the past few years will be completed within one year,and the corresponding survey cycle will be greatly shortened.In this context,the detection technology while drilling has attracted widespread attention,but the current technology-while-drilling technology is widely used in the acquisition of rock mechanical parameters such as hard rock and soft rock,and how to consider the nonlinearity of hard soil and solve it in engineering investigation has become an urgent problem to be solved in engineering applications and research.Therefore,the fast,accurate and efficient acquisition of in situ parameters of hard soil and other materials will be a major focus of future research!In this paper,the process of hard soil spinning penetration is analyzed by theoretical dcrivation.Secondly,ABAQUS nunerical software is used to simulate and analyze the rotational drilling process of hard soil,and the numerical simulation results are verified by experiments.Finally,an intelligent analysis platform based on spinning penetration technology is established,The main research oontents and achievements are as follows:(1)Study on the mechanical mechanism of hard soil spinning penetration processBy analyzing the force situation of the conical drill bit and the stress state of the contact surface during the drilling process,and analyzing the spinning penetration process based on the theory of elastoplastic mechanics,the spinning penetration mechanism of hard soil was studied,The expressions of the influence coeflicient of cone tip resistance and torque influnence coefficient in the process of spinning penetration are derived,and the change law of them with drilling speed and rotation speed,as well as the relationship between total cone tip resistance and torque are studied.(2)Study on response characteristics of rotational drilling process of hard soil and influence of drilling parametersThe nonlinear dynamic model of conical drill bit rotation drilling into hard soil is established,and the variation law of Mises stress,plastic zone and large,medium and small principal stress of hard soil during drilling is obtained.The relationship between drilling parameters(drilling speed,rotational speed)and drilling pressure and torque,as well as the relationship between drilling pressure and torque,under different soil parameters,was analyzed.Finally,the numerical simulation results are verified by the indoor spinning penetration test results.(3)Research and development of intelligent analysis platform based on spinning penetrationBased on the MATLAB GUI module,combined with artificial intelligence theory,BP neural network and digital platform construction theory,the geotechnical engineering problems are digitally processed and an intelligent analysis platform is developed.The relevant parameters of spinning penetration in the actual project can be analyzed,according to which the parameters(cohesion,internal friction angle)of hard soil under complex conditions can be quickly obtained,and the error is found to be within 30%through case verification,which proves the effectiveness and feasibility of the intelligent analysis platform.In this paper,theoretical derivation,numerical simulation and experimental verification,and intelligent analysis platform research and development are used to study the acquisition of in-situ parameters of hard soil.It proves the effectiveness of determining the in-situ parameters(cohesion,internal friction angle)of hard soil based on spinning penetration technology,and provides theoretical and technical support for the rapid,accurate and efficient acquisition of hard soil in-situ parameters in actual engineering on site,according to which the in-situ mechanical properties of hard soil can be studied,and the related research has certain theoretical significance and engineering application value!...