scholarly journals Study on Optimum Free-face Condition of Cutting Hard Rock with Tunnel Boring Machine Hob

Author(s):  
Xuhui Zhang ◽  
Yashi Liao ◽  
Zhongxiang Chen ◽  
Yimin Xia ◽  
Kui Zhang

To explore the rock-breaking characteristics of cutting hard rock under free-face condition by tunnel boring machine (TBM) hob and obtain the optimum free-face condition, the rock-breaking processes such as crack propagation, amount of micro crack and reaction force with penetration depth are first investigated based on discrete element simulation method. Then, the crack length, rock chip area, specific energy consumption etc. with different free-face spacing (S) and free-face height (H) are studied combined with rock-cutting simulation and experiment. The research results show that the formation of the rock chip under free-face condition by TBM hob is driven by tensile failure, and it exists an optimum free-face condition with the S of 80 mm and the H of 200 mm to promote main crack propagation and enhance the rock-cutting efficiency, which can provide a reference for the application of rock-breaking technology under the free-face.

2016 ◽  
Vol 49 (11) ◽  
pp. 4459-4472 ◽  
Author(s):  
Qi Geng ◽  
Zhengying Wei ◽  
Hao Meng ◽  
Francisco Javier Macias ◽  
Amund Bruland

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401875472 ◽  
Author(s):  
Wei Sun ◽  
Xiaobang Wang ◽  
Maolin Shi ◽  
Zhuqing Wang ◽  
Xueguan Song

A multidisciplinary design optimization model is developed in this article to optimize the performance of the hard rock tunnel boring machine using the collaborative optimization architecture. Tunnel boring machine is a complex engineering equipment with many subsystems coupled. In the established multidisciplinary design optimization process of this article, four subsystems are taken into account, which belong to different sub-disciplines/subsytems: the cutterhead system, the thrust system, the cutterhead driving system, and the economic model. The technology models of tunnel boring machine’s subsystems are build and the optimization objective of the multidisciplinary design optimization is to minimize the construction period from the system level of the hard rock tunnel boring machine. To further analyze the established multidisciplinary design optimization, the correlation between the design variables and the tunnel boring machine’s performance is also explored. Results indicate that the multidisciplinary design optimization process has significantly improved the performance of the tunnel boring machine. Based on the optimization results, another two excavating processes under different geological conditions are also optimized complementally using the collaborative optimization architecture, and the corresponding optimum performance of the hard rock tunnel boring machine, such as the cost and energy consumption, is compared and analysed. Results demonstrate that the proposed multidisciplinary design optimization method for tunnel boring machine is reliable and flexible while dealing with different geological conditions in practical engineering.


2020 ◽  
Vol 35 (2) ◽  
pp. 57-74
Author(s):  
Mohammad Hossein Arbabsiar ◽  
Mohammad Ali Ebrahimi Farsangi ◽  
Hamid Mansouri

Author(s):  
Chengjun Shao ◽  
Jianfeng Liao ◽  
Xiuliang Li ◽  
Hongye Su

The cutterhead driving system of tunnel boring machine is one of the key components for rock cutting and excavation. In this paper, a generalized nonlinear time-varying dynamic model is established for the hard rock TBM cutterhead driving system. Parametric uncertainties and nonlinearities and unknown disturbances exist in the dynamic model. An adaptive robust control strategy is proposed to compensate the uncertainties and nonlinearities to achieve precise cutterhead rotation speed control. In order to simulate the comprehensive performances of adaptive robust control controller, three different kinds of external force disturbances are added in this model. Compared to the traditional PID, ARC can effectively handle the different kinds of external force disturbances with sufficient small tracking errors.


2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985345 ◽  
Author(s):  
Jianbin Li ◽  
Zhange Zhang ◽  
Zhichao Meng ◽  
Junzhou Huo ◽  
Zhaohui Xu ◽  
...  

Fatigue damage is one of the most common failure modes of large-scale engineering equipment, especially the full-face tunnel boring machine with characteristics of a thick plate structure bearing strong impact load. It is difficult to predict the location and propagation life of crack of cutterhead under strong impact load. Unseasonal maintenance of equipment caused by inaccurate prediction of life cycle of cutterhead seriously affects the construction efficiency of the equipment and the life safety of the operators. Determining the crack location of tunnel boring machine cutterhead structure under strong impact load and predicting the crack propagation life are difficult scientific problems. To solve them, first, the location of the stress concentration of the cutterhead is determined by using finite element analysis method of statics. Second, prediction model for crack propagation life of tunnel boring machine cutterhead characteristic substructure based on time integration is built. And the test of crack growth of cutterhead characteristic substructure is performed. The feasibility and accuracy of the prediction model are verified by contrasting crack prediction models and the results of the test. Finally, the life prediction of tunnel boring machine cutterhead of water diversion project in Northwest Liaoning Province is carried out by using crack propagation model based on time integration. Results show that the maximum error of theoretical prediction and experimental results of crack propagation is 16%. So the feasibility of crack propagation model based on time integration in predicting the crack growth of cutterhead is verified. It is predicted that the tunnel boring machine cutterhead panel can work normally for 5.9 km under the condition of ultimate load. Building the crack propagation model considering the influence of plate thickness and strong impact load has important research value for improving the working efficiency of engineering equipment, prolonging service time, and improving the working safety.


2013 ◽  
Vol 353-356 ◽  
pp. 1417-1421 ◽  
Author(s):  
Bin Shen ◽  
Yi Min Xia ◽  
Jian Jian Gu ◽  
Yan Chao Tian

According to the actual working condition of the full face hard rock tunnel boring machine (TBM), a 2-D discrete element model for breaking marble by two TBM disc cutters is established, it simulates the whole progress of cracks production and propagation under different confining stress and penetration; based on CSM prediction model, forces of two cutters and specific energy consumptions are calculated to determine the best penetration. The simulating result shows that there are three kinds of breaking modes of marble under different confining stress and penetration; As well as the trend that specific energy consumption decrease first and then increase with the penetration increases, and there is optimal penetration to make specific energy consumption the lowest each confining stress. The optimal penetration and the lowest specific energy consumption are determined when confining stress range from 0 to 40MPa according to the simulation results.


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