Study on Rock-Breaking Mechanism of Axe Cutter Under High-ROP Condition and its ROP Increase Practice

Author(s):  
Weijun Yan ◽  
Bo Yang
Author(s):  
F. Lu ◽  
C. Zhang ◽  
J. Sun ◽  
J.X. Tian ◽  
M. Liu ◽  
...  

In order to improve working efficiency of the tunneling process and extend working life of disc cutter, explore the impact of cutter spacing and loading for the cutter rock-breaking effect. With the theory of rock crushing, Based on the finite element analysis software ABAQUS, the process of disc cutter breaking rock is simulated, considering the adjacent cutters sequential constraints, then, to make sure two cutter space with the method of SE in experiment.The simulation results showed that the optimal cutter spacings were both about 80mm in the same loading and the sequentially loading, but the rock-breaking effect of sequentially loading is better than the same loading. The experimental data showed that the minimum specific energy of rock breaking is appeared cutter spacing between 80mm and 90mm. Thus, the correctness and rationality of the simulation was verified. The study is good for understanding the rock-breaking mechanism of double disc cutter and has a certain promoting value to optimize TBM cutter system.Keywords:TBM, rock fragmentation, ABAQUS, cutter spacing, sequentially cutting


Author(s):  
Siqi Li ◽  
Shenglei Tian ◽  
Wei Li ◽  
Zhao Huan ◽  
Xin Ling ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaoming Lou ◽  
Bao Wang ◽  
En Wu ◽  
Mingwu Sun ◽  
Ping Zhou ◽  
...  

This paper aims at providing a sound theoretical solution to auxiliary central hole and the cutting parameters. For this purpose, the forming mechanism of V-cut cavity for cutting blasting was performed based on the hypothetical rock breaking mechanism of V-cut blasting. A theoretical solution for increasing the critical depth of the auxiliary center cuthole and the criteria for increasing the cuthole diameter of various types of cutholes when the rock attributes, explosive properties, and cuthole dip angle are constant are proposed. (1) If charging length le < 0.75H/sin θ, no auxiliary cuthole is needed. (2) If 0.75H/sin θ < le < 0.75H/sin θ + (2∼4) × 0.1, a central vertical auxiliary hole is needed. (3) If 0.75H/sin θ + (2∼4) × 0.1 < le < 0.75(H/sin θ + Hi/sin θi), a shallow inclined hole is needed. (4) If le > 0.75(H/sin θ + Hi/sin θi), both the central vertical cuthole and the shallow inclined cuthole are needed. Meanwhile, the theoretical solution was verified by numerical modelling with ANSYS/LS-DYNA. Moreover, the field implementation of the V-cut and the auxiliary hole effectively improved the blasting effect in both efficiency and economy.


2013 ◽  
Vol 798-799 ◽  
pp. 361-364
Author(s):  
Huan Huan Feng ◽  
Kui Chen ◽  
Jian Jun Zhou ◽  
Feng Yuan Li ◽  
Zhu Feng Wang

For better research on rock breaking mechanism of shield disc cutter, a kind of vertical experimental platform was designed after the characteristic analysis of existing linear cutting rig, using rock box turning to realize the rotary simulated motion of shield disc cutter. Compared with the linear device, this experiment platform overcomes the lack of real simulation of shield disc cutter movement condition. The design of comprehensive experimental platform was described particularly from the three aspects of electronic control system, hydraulic system and an adjusting device for cutter space. On the produced platform, which is the first one in China, the experiments of rolling experiment under three cutters sequential indentation were performed. The experimental data and analysis result were basically consistent with engineering data and simulation result based on RFPA. The correctness of design scheme, advancement and scientificalness of experiment platform were confirmed, with the hoping of providing dependable platform for the research on rock breaking mechanism of shield disc cutter.


2020 ◽  
Vol 13 (5) ◽  
pp. 122-131
Author(s):  
Yu Jinping ◽  
◽  
Zou Deyong ◽  
Sun Yuanxiu ◽  
Zhang Yin

Rock breaking is a complex physical process that can be influenced by various factors, such as geometrical shape and cutting angle of rock breaking tools. Experimental study of the rock breaking mechanism of personalized bits is restricted due to long cycle and high cost. This study simulated the rock breaking mechanism of polycrystalline diamond compact (PDC) bit by combining finite element method and experiment. The simulation was performed to shorten the period and reduce the cost of studying the rock breaking mechanism of PDC bits. A rock breaking finite element model for sting cutters of personalized PDC bit was established to simulate the rock breaking process. The crack propagation pattern, dynamic stress of rock breaking, and rock breaking mechanism of sting cutters of personalized PDC bit were analyzed. The correctness of the simulation results was verified through experiments. Results demonstrate that the rock breaking load increases with the crack propagation in the fracture initiation and propagation stages, with the maximum tangential force of 1062.5 N and maximum axial force of 1850.0 N. The load changes in a small range when the crack penetrates the rock, with the tangential force of 125.0–500.0 N and axial force of 375.0–875.0 N. The rock breaking mechanism of the sting cutters of bit is consistent with maximum tensile stress theory. The rock begins to break when the tensile stress of rock is 36.9 MPa. The sting cutters of personalized PDC bit have better wear resistance than the sting cutters of conventional bit. The average wear rates of personalized PDC and conventional bits are 1.74E-4 and 2.1E-4 mm/m, respectively. This study serves as reference for shortening the study period of rock breaking mechanism, efficiently designing personalized PDC bit structure, reducing bit wear, and enhancing rock breaking efficiency.


2021 ◽  
Vol 861 (7) ◽  
pp. 072062
Author(s):  
Miaoyuan Tang ◽  
Xin Huang ◽  
Qianwei Zhuang ◽  
Yixin Zhai ◽  
Chi Zhang ◽  
...  

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