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.

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.

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.

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.

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 Multiobjective Optimization Design for Structural Parameters of TBM Disc Cutter Rings Based on FAHP and SAMPGA

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Laikuang Lin ◽  
Yimin Xia ◽  
Dun Wu
Keyword(s):  
Multiobjective Optimization ◽  
Optimization Design ◽  
Structural Parameters ◽  
Rock Breaking ◽  
Ring Structure ◽  
Structure Design ◽  
Disc Cutter ◽  
Load Bearing ◽  
Geological Conditions ◽  
Weight Coefficients

As a key component of tunnel boring machines (TBMs), the disc cutter ring and its structural parameters are closely related to the TBM tunneling quality. Literature review shows that investigations on optimization design methods for cutter ring structure are seriously insufficient. Therefore, in this paper, a multiobjective optimization design model of structural parameters for disc cutter rings is developed based on the complex geological conditions and the corresponding cutter ring structure design requirements. The rock breaking capability, energy consumption, load-bearing capability, wear life, and wear uniformity of disc cutter are selected as the objectives, and the geometric structure of cutter rings, ultimate load-bearing capability, and cutterhead drive performance are determined as constraints. According to the characteristics of this model, a self-adaptive multipopulation genetic algorithm (SAMPGA) is utilized to solve the optimization problem, and the Fuzzy analytical hierarchy process (FAHP) is employed to calculate weight coefficients for multiple objectives. Finally, the applicability of the proposed method is demonstrated through a case study in a TBM project. The results indicated that the rock breaking performance and service life of the disc cutter are improved after optimization by using the proposed method. The utilization of SAMPGA effectively solves the premature local convergence problems during optimization. The geological adaptability should be considered in the cutter ring structure design, which can be realized by using the proposed method based on the suitable weight coefficients.

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.

Different Geological Conditions Affect the Results of Low Strain Integrity Testing of Piles

2011 ◽  
Vol 94-96 ◽  
pp. 692-696
Author(s):  
Zhi Qiang Zhang ◽  
Nan Gai Yi
Keyword(s):  
Boundary Conditions ◽  
Three Dimensional ◽  
Element Model ◽  
Time Curve ◽  
3 Dimensional ◽  
Geological Conditions ◽  
Dimensional Finite Element ◽  
The One ◽  
Three Dimensional Finite Element ◽  
Dimensional Wave

Low strain ingtegrity testing of pile is based on the one-dimensional wave theory.However, the pulse wave produced by hammer is actually 3-dimensional wave , whose propogation could be affected by the pile sides with different geological conditions. The effect is more obvious when the geological conditions of the pile sides become more complex. This test established three-dimensional finite element model which has fixed pile bottom and different geological conditions by applying ANSYS/LS-DYNA dynamic analysis method. The test simulated nine different boundary conditions of the pile sides. The results were divided into four groups to compare. And the velocity-time curve of the particle in different conditions was obtained. Through analyzing the simulation data, the conclusion that the stress wave is affected by the boundary conditions of the pile sides could be made.

scholarly journals Liquid CO2 Phase-Transition Rock Fracturing: A Novel Technology for Safe Rock Excavation

2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Haoyue Sui ◽  
Tianming Su ◽  
Ruilin Hu ◽  
Ke Yang ◽  
Yaxing Cheng
Keyword(s):  
Phase Transition ◽  
Rock Mass ◽  
Processing System ◽  
Field Tests ◽  
Fractal Dimensions ◽  
Dominant Frequency ◽  
Rock Breaking ◽  
Rock Breakage ◽  
Rock Fracturing ◽  
Liquid Co2

In order to determine the applicability of liquid CO2 phase-transition fracturing technology in rock mass excavations, the principles of CO2 phase-transition fracturing were analyzed, and field tests of liquid CO2 phase-transition fracturing were performed. An “Unmanned Aerial Vehicle (UAV) camera shooting + Microstructure Image Processing System (MIPS) analyzing” method was used to acquire the rock mass characteristics. Further, the Hilbert–Huang Transform (HHT) energy analysis principle was adopted to analyze the characteristics of fracturing vibration waves. The experimental results showed that during the process of fracturing, there were both dynamic actions of rock breakage due to excitation stress wave impacts, and quasi-static actions of rock breakage caused by gasification expansion wedges. In semi-infinite spaces, rock-breakage zones can mainly be divided into crushing zones, fracture zones, and vibration zones. At the same time, under ideal fracturing effects and large volumes, the fracturing granularity will be in accordance with the fractal laws. For example, the larger the fractal dimensions, the higher the proportion of small fragments, and vice versa. Moreover, the vibration waves of the liquid CO2 phase-transition fracturing have short durations, fast attenuation, and fewer high-frequency components. The dominant frequency band of energy will range between 0 and 20 Hz. The liquid CO2 phase-transition fracturing technology has been observed to overcome the shortcomings of traditional explosive blasting methods and can be applied to a variety of rock types. It is a safe and efficient method for rock-breaking excavations; therefore, the above technology effectively provides a new method for the follow-up of similar engineering practices.

scholarly journals On the Loads for Strength Design of Cutterhead of Full Face Rock Tunnel Boring Machine

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Meidong Han ◽  
Zongxi Cai ◽  
Chuanyong Qu
Keyword(s):  
Three Dimensional ◽  
Influence Factors ◽  
Tunnel Boring Machine ◽  
Element Model ◽  
Rock Breaking ◽  
Strength Properties ◽  
Tunnel Boring ◽  
Strength Design ◽  
Full Face ◽  
Rock Tunnel

AbstractCutterhead loads are the key mechanical parameters for the strength design of the full face hard rock tunnel boring machine (TBM). Due to the brittle rock-breaking mechanism, the excavation loads acting on cutters fluctuate strongly and show some randomness. The conventional method that using combinations of some special static loads to perform the strength design of TBM cutterhead may lead to strength failure during working practice. In this paper, a three-dimensional finite element model for coupled Cutterhead–Rock is developed to determine the cutterhead loads. Then the distribution characteristics and the influence factors of cutterhead loads are analyzed based on the numerical results. It is found that, as time changes, the normal and tangential forces acting on cutters and the total torque acting on the cutterhead approximately distribute log normally, while the total thrusts acting on the cutterhead approximately show a normal distribution. Furthermore, the statistical average values of cutterhead loads are proportional to the uniaxial compressive strength (UCS) of cutting rocks. The values also change with the penetration and the diameter of cutterhead following a power function. Based on these findings, we propose a three-parameter model for the mean of cutterhead loads and a method of generating the random cutter forces. Then the strength properties of a typical cutterhead are analyzed in detail using loads generated by the new method. The optimized cutterhead has been successfully applied in engineering. The method in this paper may provide a useful reference for the strength design of TBM cutterhead.

scholarly journals Empirical regularities investigation of rock mass discharge by explosion on the free surface of a pit bench

2021 ◽  
Vol 249 ◽  
pp. 334-341
Author(s):  
Igor Alenichev ◽  
Ruslan Rakhmanov
Keyword(s):  
Rock Mass ◽  
Slope Angle ◽  
Rock Breaking ◽  
Key Factors ◽  
Technological Parameters ◽  
Factors Affecting ◽  
Geological Conditions ◽  
Empirical Regularities ◽  
Main Discharge ◽  
Mass Discharge

Minimizing the discharge of blasted rock mass into the developed space of the pit is a very relevant area for study, as it allows to increase the processability of work and reduce the cost of mining. The article presents the results of experimental industrial explosions, during which the study of this issue was conducted. The main purpose of the work was to establish the key factors affecting the volume of rock mass discharge to the pit haulage berm. During the analysis of the world experience of research on this topic, the key factors affecting the formation of collapse and discharge – natural and technological – are identified. The method of conducting experiments and collecting data for analyzing the influence of technological parameters of location, charging and initiation of wells on the volume of rock mass discharge is described. It is established that the main discharge to the pit haulage berm is formed by the volume of rock mass limited by the prism of the slope angle. With a sufficient rock mass displacement from the edge of the bench crest towards the center of the block, only the wells of the 1st and 2nd rows participate in the discharge formation. Empirical dependences of the total volume of rock mass discharge on the length of the block along the bench crest, the specific consumption of explosives, the size of a rock piece P50 and the rate of rock breaking are obtained. The obtained results can be used to design the parameters of the drilling and blasting operations (DBO), as well as to predict and evaluate the possible consequences of a mass explosion in similar mining and geological conditions.

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