Through analysis on drillability of frozen soil, it is concluded that the main factors affecting the drillability of frozen soil are temperature, wave velocity, impact inductility and chiseling specific work. Based on...Through analysis on drillability of frozen soil, it is concluded that the main factors affecting the drillability of frozen soil are temperature, wave velocity, impact inductility and chiseling specific work. Based on the foundation it is discussed that applying the neural networks method to classify the drillability of frozen soil is simple and feasible, and the inputted vectors quantity of networks don’t be restricted, which make the classification on drillability of frozen soil rather well match the objective practice.展开更多
This paper proposes an analytical model to describe rock drilling processes using drag bits and rotary drills, and to induce relations among rock properties, bit shapes, and drilling parameters （rotary speed, thrust,...This paper proposes an analytical model to describe rock drilling processes using drag bits and rotary drills, and to induce relations among rock properties, bit shapes, and drilling parameters （rotary speed, thrust, torque, and stroke）. In this model, a drilling process is divided into successive cycles. Each cycle includes two motions： feed and cutting. According to this model, drilling torque includes four components generated from cutting, friction, feed, and idle running respectively, the first three items are all proportional to the UCS （uniaxial compressive strength） when the penetration rate is constant. Laboratory tests verified the correctness and effectiveness of the proposed model qualitatively. Especially, the influence of friction on the flank face and the idle running was confirmed. Field experiments were performed. The results showed good correlation between the torque, penetration rate, and UCS. The proposed model and equations engender the possibility of eliminating useless components of cutting forces when investigating the relation between mechanical data and physical properties of rocks.展开更多
文摘Through analysis on drillability of frozen soil, it is concluded that the main factors affecting the drillability of frozen soil are temperature, wave velocity, impact inductility and chiseling specific work. Based on the foundation it is discussed that applying the neural networks method to classify the drillability of frozen soil is simple and feasible, and the inputted vectors quantity of networks don’t be restricted, which make the classification on drillability of frozen soil rather well match the objective practice.
文摘This paper proposes an analytical model to describe rock drilling processes using drag bits and rotary drills, and to induce relations among rock properties, bit shapes, and drilling parameters （rotary speed, thrust, torque, and stroke）. In this model, a drilling process is divided into successive cycles. Each cycle includes two motions： feed and cutting. According to this model, drilling torque includes four components generated from cutting, friction, feed, and idle running respectively, the first three items are all proportional to the UCS （uniaxial compressive strength） when the penetration rate is constant. Laboratory tests verified the correctness and effectiveness of the proposed model qualitatively. Especially, the influence of friction on the flank face and the idle running was confirmed. Field experiments were performed. The results showed good correlation between the torque, penetration rate, and UCS. The proposed model and equations engender the possibility of eliminating useless components of cutting forces when investigating the relation between mechanical data and physical properties of rocks.
