scholarly journals Combined Early Warning Method for Rock Burst and Its Engineering Application

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Zhongcheng Qin ◽  
Tan Li ◽  
Qinghai Li ◽  
Guangbo Chen ◽  
Bin Cao
Keyword(s):  
Rock Burst ◽  
Engineering Application ◽  
Prediction Method ◽  
Accurate Method ◽  
Deformation Energy ◽  
Microseismic Monitoring ◽  
Drilling Depth ◽  
Monitoring Method ◽  
Cutting Method ◽  
Drill Cutting

Rock burst is a common mine disaster often accompanied with casualties and property damage. In order to effectively predict and prevent the rock burst occurrence, an effective and accurate method for predicting rock burst is necessary. This paper first establishes the relationship between the drilling cuttings and the releasable elastic deformation energy. However, the traditional drilling cutting method has the defect that the drilling depth cannot reach the stress concentration area and the drilling cuttings cannot accurately reflect the internal stress variation in the deep part of coal body. So, an improved drill cutting method is presented to make up for these defects. Finally, the combined monitoring method based on the improved drilling cutting method and the microseismic monitoring method is established. It not only overcomes the limitations of a single prediction method but also effectively utilizes the advantages of improved drilling cutting method and the microseismic monitoring method. And this combined monitoring method is applied to the No. 3302 coalface of Xingcun Coal Mine. The obtained results indicate that the combined monitoring method can improve the prediction capabilities of the rock burst and provide novel insights for preventing the rock burst occurrence.

scholarly journals Rock Burst Evaluation Using the CRITIC Algorithm-Based Cloud Model

2021 ◽  
Vol 8 ◽  
Author(s):  
Jiachuang Wang ◽  
Mingjian Huang ◽  
Jiang Guo
Keyword(s):  
Compressive Strength ◽  
Rock Burst ◽  
Uniaxial Compressive Strength ◽  
Cloud Model ◽  
High Stress ◽  
Prediction Method ◽  
Deformation Energy ◽  
Prediction And Prevention ◽  
Calculation Results ◽  
Factor Interactions

Under high-stress conditions, rock burst disasters can significantly impact underground civil engineering construction. For underground metal mines, rock burst evaluations and prevention during mining have become major research topics, and the prediction and prevention of rock burst must be based on the study of rocks and rock burst tendencies. To further prevent the risk of geological disasters and provide timely warnings, a finite-interval cloud model based on the CRITIC algorithm is proposed in this paper to address the uncertainty of rock burst evaluation, the complexity under multi-factor interactions, and the correlations between factors, and it then realizes a preliminary qualitative judgment of rock burst disasters. This paper selects the uniaxial compressive strength σc (I1), ratio of the uniaxial compressive strength to the tensile strength σc/σt (brittleness coefficient, I2), elastic deformation energy index Wet (I3), ratio of the maximum tangential stress to the uniaxial compressive strength σθ /σc (stress coefficient, I4) of the rock, depth of the roadway H (I5), and integrity coefficient of the rock mass Kv (I6) as indicators for rock burst propensity predictions. The CRITIC algorithm is used to consider the relationships between the evaluation indicators, and it is combined with an improved cloud model to verify 20 groups of learning samples. The calculation results obtained by the prediction method are basically consistent with the actual situation. The validity of the model is tested, and then the model is applied to the Dongguashan Copper Mine in Tongling, Anhui Province, China, for rock burst evaluation.

scholarly journals Evolution Mechanism, Monitoring, and Early Warning Method of Water Inrush in Deep-Buried Long Tunnel

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Wenfeng Tu ◽  
Liping Li ◽  
Shuai Cheng ◽  
Diyang Chen ◽  
Yongcai Yuan ◽  
...  
Keyword(s):  
Early Warning ◽  
Water Inrush ◽  
Engineering Application ◽  
Warning System ◽  
Microseismic Monitoring ◽  
Integrated Monitoring ◽  
Monitoring Method ◽  
Time Space ◽  
Precursor Information ◽  
Monitoring And Early Warning

Water inrush is a serious disaster in tunnel construction. Because the process of water inrush is complicated and there is no effective monitoring and early warning method, the control of water inrush disaster is passive. Firstly, the failure mode and determination method of safety thickness of the antioutburst structure are summarized. The key breakthrough directions and development trends of water inrush mechanism was analyzed. Secondly, the sensitivity ranking and the adjunct characteristics of different types of precursor information are determined by the model test. An improved scheme of microseismic monitoring technology is proposed to locate the spatial position of the water inrush channel, and a multi-information time-space integrated monitoring method for an antioutburst structure is established. By analyzing the evolution law of multi-information in the process of water inrush, the evolution model and its identification method are put forward. Finally, the level of water inrush was determined through the analysis of the dynamic and static reserves of disaster source, and a multilevel and comprehensive warning system of tunnel water inrush is established. Through the remote real-time monitoring and early warning platform and its engineering application, the early warning of water inrush time trend and the early warning of water inrush rupture space position are realized.

scholarly journals Controlling Mechanism of Rock Burst by CO2 Fracturing Blasting Based on Rock Burst System

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Tianwei Lan ◽  
Chaojun Fan ◽  
Jun Han ◽  
Hongwei Zhang ◽  
Jiawei Sun
Keyword(s):  
Coal Mining ◽  
Rock Burst ◽  
Coal Mine ◽  
Prevention And Control ◽  
Stress Measurement ◽  
Tectonic Stress ◽  
Microseismic Monitoring ◽  
Time Space ◽  
Controlling Mechanism ◽  
And Control

Rock burst induced by mining is one of the most serious dynamic disasters in the process of coal mining. The mechanism of a rock burst is similar to that of a natural earthquake. It is difficult to accurately predict the “time, space, and strength” of rock burst, but the possibility of rock burst can be predicted based on the results of microseismic monitoring. In this paper, the rock burst system under the tectonic stress field is established based on the practice of coal mining and the result of mine ground crustal stress measurement. According to the magnitude of microseismic monitoring, the amount of the energy and spatial position of the rock burst are determined. Based on the theory of explosion mechanics, aiming at the prevention and control of rock burst in the coal mine, the technique of liquid CO2 fracturing blasting is put forward. By the experiment of blasting mechanics, the blasting parameters are determined, and the controlling mechanism of rock burst of liquid CO2 fracturing blasting is revealed. The application of liquid CO2 fissure blasting technology in the prevention and control of rock burst in Jixian Coal Mine shows that CO2 fracturing blasting reduces the stress concentration of the rock burst system and transfers energy to the deeper part, and there is no open fire in the blasting. It is a new, safe, and efficient method to prevent and control rock burst, which can be applied widely.

scholarly journals Remaining Useful Life Prediction of Lithium-Ion Batteries Based on Wiener Processes with Considering the Relaxation Effect

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1685 ◽  
Author(s):  
Xiaodong Xu ◽  
Chuanqiang Yu ◽  
Shengjin Tang ◽  
Xiaoyan Sun ◽  
Xiaosheng Si ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Estimation Method ◽  
Engineering Application ◽  
Prediction Method ◽  
Lithium Ion ◽  
Relaxation Effect ◽  
Remaining Useful Life ◽  
Parameters Estimation ◽  
Wiener Processes ◽  
Useful Life

Remaining useful life (RUL) prediction has great importance in prognostics and health management (PHM). Relaxation effect refers to the capacity regeneration phenomenon of lithium-ion batteries during a long rest time, which can lead to a regenerated useful time (RUT). This paper mainly studies the influence of the relaxation effect on the degradation law of lithium-ion batteries, and proposes a novel RUL prediction method based on Wiener processes. This method can simplify the modeling complexity by using the RUT to model the recovery process. First, the life cycle of a lithium-ion battery is divided into the degradation processes that eliminate the relaxation effect and the recovery processes caused by relaxation effect. Next, the degradation model, after eliminating the relaxation effect, is established based on linear Wiener processes, and the model for RUT is established by using normal distribution. Then, the prior parameters estimation method based on maximum likelihood estimation and online updating method under the Bayesian framework are proposed. Finally, the experiments are carried out according to the degradation data of lithium-ion batteries published by NASA. The results show that the method proposed in this paper can effectively improve the accuracy of RUL prediction and has a strong engineering application value.

A Prediction Method for the Local Entropy Generation Rate in a Transitional Boundary Layer With a Free Stream Pressure Gradient

2002 ◽  
Author(s):  
Ed Walsh ◽  
Roy Myose ◽  
Mark Davies
Keyword(s):  
Boundary Layer ◽  
Entropy Generation ◽  
Prediction Method ◽  
Accurate Method ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Suction Surface ◽  
Turbulent Region ◽  
Percentage Difference ◽  
Moderate Reynolds Number

To design an aerodynamically efficient blade the distribution of entropy generation on the blade surface should be known. Having only knowledge of the integrated loss, makes the task of improving the efficiency of a blade extremely difficult. A method to predict the entropy generation rate in steady, two-dimensional, incompressible, adiabatic boundary layer flows is presented, which gives both the distribution and magnitude of the entropy generation rate. This prediction method is based upon five correlations which are used to determine the: 1. entropy generated in the laminar region; 2. entropy generated in the turbulent region; 3. location of transition; 4. length of transition; 5. entropy generated in the transition region. These are then used to predict the entropy generation rate on the suction surface of a turbine rotor blade at a moderate Reynolds number; comparisons are then drawn with past measurements. The aim is to develop a quick, simple and relatively accurate method for the prediction of entropy in the boundary layers of turbomachines, although the method is not confined to this application. The only information required to implement this prediction method is the boundary layer edge velocity distribution and the turbulence intensity. A benefit of this method is that it does not rely upon dissipative CFD predictions, which are both slow to use in a design process and not yet sufficiently trustworthy. The dissipation coefficient and entropy generation rate predicted for this test case compare well to experimental measurements, with the percentage difference between the integrated entropy measured and predicted being approximately 13%. However, the difference in the turbulent region is found to be as high as 30%.

Stress Real-Time Monitoring of Marine Derrick Based on Environmental Loads

2012 ◽  
Vol 226-228 ◽  
pp. 2128-2131
Author(s):  
Tao Huang ◽  
Jun Pu Wang ◽  
Fu Wan ◽  
Shao Wei Chen ◽  
Yao Dong
Keyword(s):  
Finite Element ◽  
Real Time ◽  
Engineering Application ◽  
Design Feature ◽  
Environmental Load ◽  
Real Time Monitoring ◽  
Element Analysis ◽  
Monitoring Method ◽  
Environmental Loading ◽  
Finite Element Software

Aiming at the design feature and the operating of K-type derrick, an effective method used to stress real-time monitoring consider environmental loading is proposed. The challenge to the South China Sea offshore drilling derrick is a illustration. The derrick corrosion and wall thinning conditions is be considered, then using finite element software analyze derrick structure of static analysis, get the higher force about main member of derrick. Based on finite element analysis, select the key parts layout of measuring points, then monitor derrick stress under nine storms environmental loading and extreme work condition. The measured data results show that: the nine storms environmental load affect capacity of drilling significantly, the different parts of the main member stress have the different degrees of influence by environmental load, the maximum can reach 50.8%. This real-time monitoring method of stress, can protect the safety of marine operations, has a certain value of engineering application.

Establishment and Application of Microseismic Monitoring System to Deep-Buried Underground Powerhouse

2013 ◽  
Vol 838-841 ◽  
pp. 889-893
Author(s):  
Biao Li ◽  
Feng Dai ◽  
Nu Wen Xu ◽  
Chun Sha
Keyword(s):  
Rock Mass ◽  
Monitoring System ◽  
Wave Velocity ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
P Wave ◽  
Monitoring Method ◽  
Underground Powerhouse ◽  
Geological Conditions ◽  
The Stability

The right bank underground powerhouse of Houziyan hydropower station is a typical deep-buried type with high geostress and complicated geological conditions. To monitor and analyze the stability of surrounding rock mass during continuous excavation of the powerhouse excavation and locate the potential failure zones, an ESG (Engineering Seismology Group) microseismic monitoring system manufactured in Canada was installed in April, 2013. The wave velocity of the monitoring system was determined through fixed blasting tests. And the average location error is the minimum while P-wave velocity is 5700m/s, less than 10m and meeting the system request. By combining the temporal and spatial distribution regularity of microseimic events with field excavation, micro-crack clusters and potential instability zones were identified and delineated. The results will provide a reference for later excavations and supports of the underground powerhouse. Furthermore, a new monitoring method can also be supplied for the stability analysis of surrounding rock mass in deep-buried underground powerhouses.

The Design and Implementation of Condition Monitoring and Decision Support System in HVDC Converter Station

2015 ◽  
Vol 734 ◽  
pp. 707-713
Author(s):  
Wei Wei Jin ◽  
Cun Yu ◽  
Xing Chao Yang ◽  
Zhan Xia Geng ◽  
Hao Ran Zhang ◽  
...  
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Condition Monitoring ◽  
Support System ◽  
Engineering Application ◽  
Monitoring Method ◽  
Design And Implementation ◽  
On Line ◽  
Grid Construction ◽  
Condition Monitoring System

The shortcomings of current on-line condition monitoring system include: the research was concentrated in AC substation; the function was single and completely independent; the protocols were not compatible and the interface was not unified. To improve these disadvantages and better satisfy the needs of the condition monitoring in converter station, the design and implementation of condition monitoring and decision support system in HVDC converter station was realized. By studying of condition monitoring method, decision support technology and engineering application of HVDC project, the system design principle was discussed, the software structure was shown and the function realization was given in detail. The implementation realized real time monitoring for running equipments, provided reliable gist for maintenance and reduced the costs of resources. The implementation is applied to HVDC project witch has a great significance in improving the operation efficiency and promoting the smart grid construction.

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