scholarly journals Dynamic Rock-Breaking Process of TBM Disc Cutters and Response Mechanism of Rock Mass Based on Discrete Element

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Qinglong Zhang ◽  
Yanwen Zhu ◽  
Canxun Du ◽  
Sanlin Du ◽  
Kun Shao ◽  
...  
Keyword(s):  
Rock Mass ◽  
Failure Modes ◽  
Confining Pressure ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Repeated Loading ◽  
Response Mechanism ◽  
Disc Cutters ◽  
Crack Penetration ◽  
Cutter Spacing

Rock-breaking efficiency of full-face rock tunnel boring machine (TBM) is closely related to the performance of the disc cutter and the characteristics of the rock mass. In the point of view of mesomechanics, the particle flow code (PFC) is used to establish a numerical model of the rock mass and the disc cutter, and the process of TBM disc cutter intrusion into the rock mass is analyzed. The dynamic response mechanism and crack evolution process of the rock mass under the action of the disc cutter are studied on the basis of micromechanics, and the relationship between the rock mass crack, penetration, and cutting force during the intrusion of the disc cutter is revealed. The sensitivity analysis is carried out on the confining pressure conditions and the influence parameters of the disc cutter spacing. The results show that the rock breaking by disc cutter undergoes the transformation characteristics of compaction, shearing, and tension failure modes, and the failure process of the rock mass is the joint action of tension and shear. In the whole process of rock breaking, the disc cutter has the phenomenon of repeated loading-unloading alternation and leaping rock breaking; after the penetration of the disc cutter reached 9.0 mm, penetration creaks begin to appear on the surface of the rock mass; the penetration was obviously reduced with the increase of confining pressure, and it is mainly the penetration cracks on the surface; after the disc cutter spacing reaches 100.0 mm, there is no penetration crack between the two disc cutters. The research conclusion can provide a reference for the disc cutter optimization design.

Numerical Simulation of the Rock Fragmentation Process Induced by TBM Cutters

2012 ◽  
Vol 249-250 ◽  
pp. 1069-1072 ◽  
Author(s):  
Gang Li ◽  
Bo Wang ◽  
Ya Dong Chen ◽  
Wan Shan Wang
Keyword(s):  
Rock Mass ◽  
Rock Breaking ◽  
Rock Fragmentation ◽  
Fragmentation Process ◽  
Disc Cutter ◽  
Material Strength ◽  
Joint Spacing ◽  
Geological Conditions ◽  
Breaking Mechanism ◽  
Cutter Spacing

The rock fragmentation process is the interaction process between TBM and rock mass, which is affected by TBM specifications, such as thrust force, cutter tip width and profile, cutter spacing, RPM, and torque, and rock mass properties mainly including rock material strength, rock brittleness, joint spacing and orientation. In this study, based on the systematic study of the existed rock constitutive model achievements and introduction of rock breaking mechanism, main failure mode of rock in the breaking process of disc cutter is added and revised in order to meet the actual situation. The method of establishing numerical model of disc cutter breaking process is introduced. After the dynamic simulation, we can obtain that geotechnical interface disturbance insulted by disc cutter. Based on plenty of experiments, it confirms reliability of numerical methods and provides a method to study cutting performance for different geological conditions.

Research on Breaking Energy Mechanism of Tunnel Boring Machine Disc Cutter Rock with CSM Model

2014 ◽  
Vol 651-653 ◽  
pp. 988-991 ◽  
Author(s):  
Nan Zhao ◽  
Li Wei Song
Keyword(s):  
Energy Efficiency ◽  
Energy Transfer ◽  
Rock Mass ◽  
Tunnel Boring Machine ◽  
Rock Breaking ◽  
Energy Output ◽  
Disc Cutter ◽  
Efficiency Ratio ◽  
Tunnel Boring ◽  
Cutter Spacing

Full face rock tunnel boring machine in construction process, disc cutter put pressure on rock breaking, actually belongs to the process of energy transfer, from the point of view of energy analysis the energy transfer rules in the process of disc cutter rock breaking, based on CSM force prediction model, analysis disc cutter energy input and rock mass energy output efficiency ratio, for excavation with minimum energy efficiency. Taking S-536 Hong Kong water tunnel TBM as an example, When the penetration is 10mm, based on the energy efficiency ratio the optimal disc cutter spacing should be less than 70mm, than the actual average disc cutter spacing is small 2mm, rock mass as a reference the disc cutter rock breaking efficiency mechanism provides certain reference value for the cutter layout.

Numerical Simulation of Rock Fragmentation Process for TBM Cutters Based on Three-Dimensional Dynamic Fracturing Method

2012 ◽  
Vol 472-475 ◽  
pp. 2033-2036
Author(s):  
Gang Li ◽  
Li Da Zhu ◽  
Jian Yu Yang ◽  
Wan Shan Wang
Keyword(s):  
Rock Mass ◽  
Three Dimensional ◽  
Element Model ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Material Strength ◽  
Rock Breakage ◽  
Joint Spacing ◽  
Geological Conditions ◽  
Cutter Spacing

The rock breakage process is the interaction process between TBM and rock mass, which is affected by TBM specifications, such as thrust force, cutter tip width and profile, cutter spacing, RPM, and torque, and rock mass properties mainly including rock material strength, rock brittleness, joint spacing and orientation. In this study, based on the systematic study of the existed rock constitutive model achievements and introduction of rock breaking mechanism, main failure mode of rock in the breaking process of disc cutter is added and revised in order to meet the actual situation. The method of establishing finite element model of disc cutter breaking process using ANSYS AUTODYN-3D software is introduced. After the dynamic simulation, we can obtain that geotechnical interface disturbance insulted by disc cutter. Based on plenty of experiments, it confirms reliability of numerical methods and provides a method to study cutting performance for different geological conditions.

Research on the Optimal Disc Cutter Spacing for Rock-Breaking Based on ANSYS

2014 ◽  
Vol 664 ◽  
pp. 143-147
Author(s):  
Yan Li ◽  
Ke Zhang ◽  
Jian Sun ◽  
Hong Sun ◽  
Zi Nan Wang
Keyword(s):  
Finite Element ◽  
Rock Breaking ◽  
Rock Fragmentation ◽  
Cutting Process ◽  
Disc Cutter ◽  
Rock Stress ◽  
Fragmentation Efficiency ◽  
Finite Element Software ◽  
Disc Cutters ◽  
Cutter Spacing

Objective: To study the influence of disc cutter spacing on rock fragmentation efficiency and optimize cutter layout and improve the efficiency of disc cutter. Method: ANSYS, a finite element software was used to simulate double disc cutter cutting process. Result: Find a good corresponding relationship between penetration and cutter spacing. At the process of sandstone, if disc cutter spacing as 54 ~ 55 mm, rock crushing as the largest and rock fragmentation efficiency is the highest; with the penetration of 10 mm. If disc cutter spacing as 66~68.5mm, rock crushing as the largest and rock fragmentation efficiency is the highest with the penetration of 15 mm. Changing the cutter spacing and penetration, rock stress and broken degree will also change. Conclusion: Double disc cutters change within the range of best cutter spacing, cutter spacing is proportional to the rock crushing. If the cutter distance is greater than the best cutter spacing, the ledge will be appeared. For one type of rocks, the penetration would have some effects on the optimal cutter spacing. If the penetration increases, the optimal cutter spacing increases gradually, at the time of other construction parameters unchanged.

Study on Rock-Breaking Simulation and Experiment of Double Disc Cutter of TBM

2016 ◽  
Vol 23 ◽  
pp. 80-88
Author(s):  
F. Lu ◽  
C. Zhang ◽  
J. Sun ◽  
J.X. Tian ◽  
M. Liu ◽  
...  
Keyword(s):  
Rock Breaking ◽  
Disc Cutter ◽  
Element Analysis ◽  
Breaking Effect ◽  
The Finite Element Analysis ◽  
Breaking Mechanism ◽  
Simulation And Experiment ◽  
Tbm Cutter ◽  
Cutter Spacing ◽  
The Impact

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

scholarly journals Permeability Characteristic and Failure Behavior of Filled Cracked Rock in the Triaxial Seepage Experiment

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xinyu Liu ◽  
Zhende Zhu ◽  
Aihua Liu
Keyword(s):  
Growth Rate ◽  
Rock Mass ◽  
Failure Modes ◽  
Peak Stress ◽  
Confining Pressure ◽  
Strength Characteristics ◽  
Failure Behavior ◽  
Compression Tests ◽  
Secondary Cracks ◽  
Safety And Stability

Filling is commonly found in natural cracked rock mass. As the weakest part of the rock, the filling properties directly affect the rock deformation and strength, permeability, and so on and affect the safety and stability of the rock mass engineering. In this study, a single slit has been preset in sandstones and filled with different physical properties materials. Based on the laboratory triaxial seepage test, the permeability and strength characteristics of filled cracked sandstones are analyzed, and the failure modes are obtained. The main findings of this study are as follows: (1) The permeability coefficient peak value of the filled cracked rock appears before the stress peak. (2) At the same confining pressure growth rate, the peak stress growth rate of the filled cracked rock is generally higher than that of the intact rock and the strength growth rate of the cracked rock increases with the length of the fracture. The strength characteristics of the filling in the uniaxial compression tests and triaxial seepage tests are significantly affected by the hydraulic properties. (3) The strength and permeability coefficients of cracked rock filled with cement mortar are more sensitive to the change of confining pressure, while under the same condition, the ones of cracked rock filled with gypsum mortar are stable. (4) According to the failure mechanism, under the seepage stress, the secondary cracks can be divided into 3 types and the failure modes can be divided into 2 types.

The Numerical Simulations of Forces Acting on TBM Disc Cutters with the Consideration of Confining Pressure and Damage in Rocks

2011 ◽  
Vol 105-107 ◽  
pp. 1170-1174
Author(s):  
Hui Yun Li ◽  
Guang Yu Shi
Keyword(s):  
Penetration Depth ◽  
Cutting Forces ◽  
Confining Pressure ◽  
Material Model ◽  
Disc Cutter ◽  
Finite Element Software ◽  
Linear Dynamic ◽  
Dynamic Finite Element ◽  
Disc Cutters ◽  
The Relationship

This paper gives a brief explanation of the failure mechanism of rock fragmentation in rock cutting. The JOHNSON_HOLMGIST_CONCRETE is selected as the rock material model in numerical simulation with confining pressure and damage influence introduced. We use the non-linear dynamic finite element software LS/DYNA to simulate the dynamic process of cutting rock. The cutting forces acting on disc cutter are computed. The relationship between cutting forces and penetration depth, confining pressure and damage parameters are obtained. The results show that, the cutting forces increase with the penetration depth. They are larger in equal confining pressure than unequal condition. The forces are amplified with the damage parameters increasing. The conclusion provides a reference for the prediction of the cutting forces.

scholarly journals The Effects of Confining Stress on Rock Fragmentation by TBM Disc Cutters

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
S. F. Zhai ◽  
S. H. Cao ◽  
M. Gao ◽  
Y. Feng
Keyword(s):  
Confining Pressure ◽  
Numerical Results ◽  
Rock Fragmentation ◽  
Disc Cutter ◽  
Confining Stress ◽  
Disc Cutters ◽  
Initiation And Propagation ◽  
Maximum Angle ◽  
Indentation Tests ◽  
Crushed Zone

In this paper, General Particle Dynamics (GPD3D) is developed to simulate rock fragmentation by TBM disc cutters under different confining stress. The processes of rock fragmentation without confining pressure by one disc cutter and two disc cutters are investigated using GPD3D. The crushed zone, initiation and propagation of cracks, and the chipping of rocks obtained from the proposed method are in good agreement with those obtained from the previous experimental and numerical results. The effects of different confining pressure on rock fragmentation are investigated using GPD3D. It is found that the crack initiation forces significantly increase as the confining stress increases, while the maximum angle of cracks decreases as the confining stress increases. The numerical results obtained from the proposed method agree well with those in previous indentation tests. Moreover, the effects of equivalent confining stress on rock fragmentation are studied using GPD3D, and it is found that rock fragmentation becomes easier when the equivalent confining stress is equal to 15MPa.

Distribution Law of Excavating Load of TBM Disc Cutter and Cutterhead

2014 ◽  
Vol 615 ◽  
pp. 22-26
Author(s):  
Xiang Heng Zhu ◽  
Yi Min Xia ◽  
Tao Ouyang ◽  
Kai Yang
Keyword(s):  
Yield Criterion ◽  
Tunnel Boring Machine ◽  
Element Model ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Distribution Law ◽  
Disc Cutters ◽  
Lateral Forces ◽  
Simulation Results ◽  
Thrust And Torque

Cutterheads and disc cutters are the key components of Tunnel Boring Machine (TBM) used to fulfill the rock-breaking task. In order to study the variation and distribution law of cutting forces induced by disc cutters on TBM cutterhead, a finite element model of rock-breaking process is established based on the extended Drucker-Prager yield criterion for rock and then the excavating process of cutterhead is simulated. The simulation results show that: in the rock fragmentation process, the rock-breaking forces are step changing; with the increase of installation radius, the vertical forces of inner and face cutters increase, while the lateral forces decrease; with the increase of installation angle, the vertical forces of edge disc cutters decrease, while the lateral forces increase; the mean total thrust and torque of cutterhead are 5418.2 kN and 1624.4 kN·m respectively, the simulation results are verified by engineering data.

Research on the Rock Breaking by Double Disc Cutter Test-Bed

2013 ◽  
Vol 690-693 ◽  
pp. 2484-2489 ◽  
Author(s):  
Peng Zhou ◽  
Chao Wang ◽  
Wei Xian Gao ◽  
Yu Hou Wu
Keyword(s):  
Maximum Stress ◽  
Tunnel Boring Machine ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Test Bed ◽  
Underground Engineering ◽  
Tunnel Boring ◽  
Disc Cutters ◽  
Optimal Spacing ◽  
Rock Tunnel

Rock tunnel boring machine is one of the main machineries and equipments for underground engineering, and the failure of tool systems is its main failure form. Rock hob test-bed is the only testing equipment for tool failure and wear. In this paper, the breaking rock by the double disc cutter is simulated and four kinds of rocks are selected to test the influece of rock characteristics and spacing between two disc cutters on the rock breaking by the double disc cutter test-bed. The results show that there is different optimal spacing between two disc cutters for different rock; the optimal spacing is inversely proportional to the hardness of the rocks; the maximum stress appears the boundary between the disc cutter and rock.

Sign in / Sign up

Export Citation Format

Share Document