Application of Midas GTS Three Dimensional Numerical Simulation New Technology to the Stability of Hole Wall in HDD Engineering

ICPTT 2012 ◽  
2012 ◽  
Author(s):  
Yuanliang Liu
2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Gen Ge ◽  
Wei Wang

The analytical method to predict the period-doubling bifurcation of the three-dimensional (3D) system is improved by using the undetermined fundamental frequency method. We compute the stable response of the system subject to the quadratic and cubic nonlinearity by introducing the undetermined fundamental frequency. For the occurrence of the first and second period-doubling bifurcation, the new bifurcation criterion is accomplished. It depends on the stability of the limit cycle on the central manifold. The explicit applications show that the new results coincide with the results of the numerical simulation as compared with the initial methods.


2020 ◽  
Vol 9 (1) ◽  
pp. 72
Author(s):  
Pisith Mao ◽  
Hideki Shimada ◽  
Akihiro Hamanaka ◽  
Sugeng Wahyudi ◽  
Jiro Oya ◽  
...  

A study of multiple seams longwall mining is proposed to investigate its applicability in Indonesia coal mine. The study area of this research is PT Gerbang Daya Mandiri (GDM) coal mine located in East Kalimantan Island. The study of seam interaction is crucial for developing multiple seams longwall mining especially when it comes to weak rock conditions which are usually found in most of the coal reserves in Indonesia. This paper will use numerical simulation to investigate the effect of the first mined-out seam on the development of the second coal seam gate-entry by considering a couple of key parameters including depth of the coal seam and interburden length. The simulation model consists of two main indicators for instability which include failure zone, the contour of safety factor. The results show that the effect of seam interaction on gate-entry has different intensity based on the thickness of the interburden and coal seam depth. This work also provided appropriate support configuration for maintaining the stability of gate-entry.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhigang Meng ◽  
Fangzheng Fan ◽  
Xuebin Cui ◽  
Shu Tao ◽  
Yi Cao

Yuanjue Cave, located in Big Buddha Bay, Mount Baoding, Dazu Rock Carvings Area, has extremely high historical, artistic, and religious value and is an important grotto cultural relic in China. Due to the cutting action of the fissures and weak interlayers, the South Cliff of Big Buddha Bay where Yuanjue Cave is located showed signs of instability. In order to fully evaluate the stability of the rock mass around the cliff where Yuanjue Cave is located, a three-dimensional geological model of the surrounding rock of Yuanjue Cave was established by using FLAC3D software, combined with three-dimensional scanning, fissure investigation, and indoor tests. The stability of the surrounding rock mass adjacent to Yuanjue Cave has been studied by precise numerical simulation, and the results of numerical simulation and monitoring have been compared and analysed. The results show the following: (1) The west of J10 fissure, above the mudstone interlayer, is the main deformation area. The cliff displacement increases gradually from the east to the west. The independent block above the corner has the largest free space displacement, and there is a risk of independent collapse. Special attention should be paid to the stability of this block. The displacement of the upper monitoring point of the cliff wall is significantly greater than that of the lower layer. (2) In the surrounding rock block in the adjacent area, the various concentrated stresses of the body are mainly located at the entrance of Yuanjue Cave, the height of the chest of the Zhengjue Buddha statue, and the lower mudstone erosion and reinforcement zone. Among them, the stress concentration in the erosion and reinforcement area under the Zhengjue Buddha statue is the largest. The conclusions obtained can provide a useful reference for the stability assessment of the surrounding rock of Yuanjue Cave.


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