scholarly journals The Stability Evaluation of Shaft during Drastic Drawdown Dewatering of Alluvium

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Mingze Du ◽  
Yanchun Xu ◽  
Heng Duan ◽  
Wen Li
Keyword(s):  
Coal Mine ◽  
Load Level ◽  
Stability Evaluation ◽  
Early Prevention ◽  
Discriminant Model ◽  
Fisher Discriminant ◽  
The Stability ◽  
And Control ◽  
Shaft Failure ◽  
Shaft Wall

The hydrophobicity of the aquifer at the bottom of the porous alluvium will affect the stability of the shaft. According to the changes of water level and the compressive amount of alluvium, we can evaluate the shaft stability and predict the shaft failure. In this work, the simulation model of the auxiliary shaft in the Zhuxianzhuang Coal Mine is generated by using the Nsdc software to evaluate the stability of the shaft during drastic drawdown dewatering. Based on the measured hydrophobic compression ratio in an adjacent coal mine, the compressive amounts of the strata near the main and auxiliary shafts in the Zhuxianzhuang Coal Mine are predicted under the condition of drastic drawdown dewatering, which will be 249.69 mm and 302.75 mm, respectively. It is more likely that the shaft wall may fracture in the 15th day (fourth load level) under the condition of drastic drawdown dewatering. The formation compressive amount near the auxiliary shaft is approximately 320 mm, which is close to the measured predicted value. At the same time, the Fisher discriminant model is established, and it is predicted that the state of the main and auxiliary shafts will be failure under the conditions of drastic drawdown dewatering in the Zhuxianzhuang Coal Mine. Based on the simulating results, the technical means of using the ground grouting for early prevention and control is proposed.

scholarly journals Stability Evaluation of an Expressway Construction Site above an Abandoned Coal Mine Based on the Overlay and Index Method

2019 ◽  
Vol 11 (19) ◽  
pp. 5163 ◽  
Author(s):  
Qingbiao Guo ◽  
Guangli Guo ◽  
Yingming Li ◽  
Lei Wang ◽  
Xingwang Zhao
Keyword(s):  
Coal Mine ◽  
Traffic Safety ◽  
Evaluation Model ◽  
Scoring Functions ◽  
Construction Site ◽  
Stability Evaluation ◽  
Index Method ◽  
Expressway Construction ◽  
The Stability ◽  
Abandoned Coal Mine

In recent years, more and more expressways pass through the abandoned coal mine, while the surface residual subsidence of the abandoned coal mine threatens the operation safety of the expressway. It is of significance to evaluate the stability of the construction site and take reasonable managements for effectively guaranteeing the traffic safety. How to accurately evaluate the stability of the construction site is the primary problem. This study proposes a stability evaluation model using the overlay and index method and points out that the evaluation scores and weights of evaluation indices are key parameters to determine the reliability of evaluation results. To reasonably determine the evaluation score, the scoring criteria of qualitative indices is obtained by the equidistant method, while the scoring criteria of quantitative indices is obtained by establishing scoring functions. The weights of evaluation indices are got by adopting the FAHP (fuzzy analytic hierarchy process). Then the built model is applied to evaluate the stability of the Wuyun Expressway construction site, and the results show that the Wuyun Expressway construction site is basic stable. Finally, the sensitivity of indices weights on the evaluation result is analyzed with the maximum C k ( C m , p c ) of 5.9% far lower than the weight change of ±30%, and the average residual subsidence velocity of the maximum subsidence point is 0.0456 mm/d using a high-resolution leveling, proving the credibility of the proposed model. Research results provide new ideas and systematic technical references for the stability evaluation of the construction site above an abandoned coal mine.

Study on the Technology Coefficient of Supporting for Deep Coal Mine Tunnels

2012 ◽  
Vol 170-173 ◽  
pp. 1392-1396
Author(s):  
Wei Zhang ◽  
Shi Hai Chen
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Maintenance Cost ◽  
Anchor Cable ◽  
Deep Coal Mine ◽  
Large Pressure ◽  
The Stability ◽  
And Control ◽  
Mine Tunnels ◽  
Coupling Support

To keep the stability of tunnel’s surrounding rock, and control the deformation of surrounding rocks and reduce the maintenance cost of tunnel in maximum, this article did the following aspects. Aiming at large pressure , large deformation , bad maintenance state in deep coal mine tunnel , joint cable anchor support technology is adopted , and the coordination deformation of tunnel is accomplished through anchor net-surrounding rock and its coupling with the anchor cable .Through the theoretical calculation and numerical simulation of cable anchor coupling support ,we determine reasonable technology coefficient of bolt supporting and verify the correctness of support coefficient by field observation.

scholarly journals Data-Driven Stability Assessment of Multilayer Long Short-Term Memory Networks

2021 ◽  
Vol 11 (4) ◽  
pp. 1829
Author(s):  
Davide Grande ◽  
Catherine A. Harris ◽  
Giles Thomas ◽  
Enrico Anderlini
Keyword(s):  
Neural Network ◽  
Network Architecture ◽  
Short Term Memory ◽  
Moving Average ◽  
Machine Learning Algorithms ◽  
Physical Models ◽  
Data Driven ◽  
The Stability ◽  
And Control ◽  
Nonlinear Autoregressive

Recurrent Neural Networks (RNNs) are increasingly being used for model identification, forecasting and control. When identifying physical models with unknown mathematical knowledge of the system, Nonlinear AutoRegressive models with eXogenous inputs (NARX) or Nonlinear AutoRegressive Moving-Average models with eXogenous inputs (NARMAX) methods are typically used. In the context of data-driven control, machine learning algorithms are proven to have comparable performances to advanced control techniques, but lack the properties of the traditional stability theory. This paper illustrates a method to prove a posteriori the stability of a generic neural network, showing its application to the state-of-the-art RNN architecture. The presented method relies on identifying the poles associated with the network designed starting from the input/output data. Providing a framework to guarantee the stability of any neural network architecture combined with the generalisability properties and applicability to different fields can significantly broaden their use in dynamic systems modelling and control.

scholarly journals New integrated monitoring and control system for disaster gas application in coal mine

2017 ◽  
Vol 191 ◽  
pp. 012051
Author(s):  
Deng-yu Zhao ◽  
Xing-ping Lai ◽  
Chang-fa Ji ◽  
Hong-jun Xi ◽  
Zhang Bo ◽  
...  
Keyword(s):  
Control System ◽  
Coal Mine ◽  
Monitoring And Control ◽  
Integrated Monitoring ◽  
Monitoring And Control System ◽  
And Control

A Design of Coal Mine Security Monitoring Substation Based on ZIGBEE and CAN Bus

2014 ◽  
Vol 971-973 ◽  
pp. 1033-1036
Author(s):  
Hui Jun Wang ◽  
Zhi Qun Yong
Keyword(s):  
Coal Mine ◽  
Can Bus ◽  
Measurement Data ◽  
Environmental Parameters ◽  
Monitoring And Control ◽  
Monitoring And Control System ◽  
Security Monitoring ◽  
Mine Development ◽  
Security Monitoring System ◽  
And Control

In view of the shortcoming such as wiring difficulties, poor scalability, and big cable usage in present mine security monitoring system, this paper puts forward a kind of substation monitoring and control system based on ZIGBEE and CAN. With the core of core, The system collects various measurement data of sensors through the ZIGBEE wireless network, realizes the to collect, and then through the CAN bus to realize the transmission of control commands and data of the up and down machine, and monitor the production parameters and environmental parameters in the coal mine. Experiments show that the monitoring substation is of high real-time performance, good stability, strong expansibility, etc., and can meet the requirements of the coal mine development and mining.

The Application of the Amorphous Metal Transformers in Heavy Oil Electric Heating System

2014 ◽  
Vol 532 ◽  
pp. 191-195 ◽  
Author(s):  
Bao Jiang Sun ◽  
Lei Su ◽  
Chao Zhang
Keyword(s):  
Electric Heating ◽  
Heating System ◽  
Intermediate Frequency ◽  
Amorphous Metal ◽  
Technical Performance ◽  
Alloy Material ◽  
Working Principle ◽  
The Stability ◽  
And Control ◽  
Fast Rise

In order to solve the problem that the big loss of no-load and the fast rise of temperature when employ the conventional silicon steel metal transformer (SSMT) in the electric heating system, we choose the amorphous metal transformer (AMMT). In this paper, firstly, we give a brief introduction of the amorphous alloy material properties and compare the no-load characteristic of the AMMT with the SSMT. Secondly, the structure of intermediate frequency heating system working principle and control strategy are introduced. Finally, extensive experiments were conducted to validate the ideas. The experiments show that the AMMT not only improve the efficiency of transformer, solve the heating problem of transformer, but also improve the stability, security and other technical performance of the system, so it is worth recommending and promoting.

scholarly journals Stability Control of Deep Coal Roadway under the Pressure Relief Effect of Adjacent Roadway with Large Deformation: A Case Study

2021 ◽  
Vol 13 (8) ◽  
pp. 4412
Author(s):  
Houqiang Yang ◽  
Nong Zhang ◽  
Changliang Han ◽  
Changlun Sun ◽  
Guanghui Song ◽  
...  
Keyword(s):  
Large Deformation ◽  
Coal Mine ◽  
High Stress ◽  
Surrounding Rock ◽  
Western China ◽  
Engineering Practice ◽  
Pressure Relief ◽  
Coal Roadway ◽  
And Control ◽  
Relief Effect

High-efficiency maintenance and control of the deep coal roadway surrounding rock stability is a reliable guarantee for sustainable development of a coal mine. However, it is difficult to control the stability of a roadway that locates near a roadway with large deformation. With return air roadway 21201 (RAR 21201) in Hulusu coal mine as the research background, in situ investigation, theoretical analysis, numerical simulation, and engineering practice were carried out to study pressure relief effect on the surrounding rock after the severe deformation of the roadway. Besides, the feasibility of excavating a new roadway near this damaged one by means of pressure relief effect is also discussed. Results showed that after the strong mining roadway suffered huge loose deformation, the space inside shrank so violently that surrounding rock released high stress to a large extent, which formed certain pressure relief effect on the rock. Through excavating a new roadway near this deformed one, the new roadway could obtain a relative low stress environment with the help of the pressure relief effect, which is beneficial for maintenance and control of itself. Equal row spacing double-bearing ring support technology is proposed and carried out. Engineering practice indicates that the new excavated roadway escaped from possible separation fracture in the roof anchoring range, and the surrounding rock deformation of the new roadway is well controlled, which verifies the pressure relief effect mentioned. This paper provides a reference for scientific mining under the condition of deep buried and high stress mining in western China.

A rapid and non-destructive method for detecting the water-holding capacity of pork using composite film

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xing Li ◽  
Xiaodan Wang ◽  
Dengyong Liu ◽  
Yanli Dong ◽  
Feng Hu
Keyword(s):  
Service Life ◽  
Composite Film ◽  
Water Holding Capacity ◽  
Detection Methods ◽  
Important Indicator ◽  
Discriminant Model ◽  
Fisher Discriminant ◽  
Water Holding ◽  
Non Destructive ◽  
Pork Samples

Abstract Water-holding capacity (WHC) is an important indicator of pork quality, but the existing detection methods of WHC are either expensive or time-consuming. In this study, a new method of pork WHC detection was developed by a composite film. The preparation method, mechanical properties and service life of the composite film were studied. The result showed that composite film was 0.46 ± 0.06 mm thick and had a service life of 21 days, tensile strength of 7.72 ± 0.11 MPa and the elongation at break of 28.54 ± 0.15%. Thirty groups of pork samples were randomly selected to build the model and another twenty groups were used to verify the model accuracy. Results showed that the accuracy of composite film coupled with Fisher discriminant model to detect the WHC of pork is 90%. This study demonstrates the high value of composite film as a detection tool to classify WHC of pork.

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