Study On Rock Breaking Capability Of Rotary Drilling Rig Under Low-frequency Dynamic Loading Pressure

Rotary drilling rig is a kind of high efficiency deep hole pouring pile construction equipment.With the large-scale infrastructure construction and the rapid development of the city in recent years,the rotary drilling rig has also developed greatly.However,conventional rotary drilling rigs are not efficient in the form of self-pressure,and the efficiency of intrusion and drilling of hard rock is not high.As a result,the life of the drill pipe and the power head is greatly reduced,which increases the engineering cost and prolongs the engineering time.Therefore,it is of great theoretical and practical value to study the rock breaking ability and rock breaking mechanism of hard rock drilling under low frequency dynamic loading.In this paper,we propose a method to provide low-frequency fluctuating and pressurizing system with the power supply system of the rotary drilling rig,and then the output method of the vertical feed by the drilling tool,and realize the dual mode of static pressure and low frequency waveform Hydraulic principle and simulation in AMESim.Based on the physical and mechanical characteristics of rock and the rock breaking mechanism of single-tooth cutting rock,the drilling rigs were studied by drilling with short auger drilling rigs,The mathematical model of the random load of the short auger and the three-dimensional model of the single-tooth cutting rock are set up.The process of single-tooth chiseling rock is limited by ANSYS software.The dynamic stress,strain and crack propagation of the rock are studied under the static load and low frequency waveform dynamic load.The results show that the low frequency dynamic load has a more significant rock breaking effect,and there is a break threshold of 36 kN.When the peak load exceeds the threshold value,the crack propagation rate increases sharply and the rock accelerates.The continuous dynamic load can promote the horizontal Direction crack development;curve load peak determines the depth of crack development.This conclusion provides a theoretical basis for the reasonable selection and control of hard rock drilling parameters for rotary drilling rig.