scholarly journals Study on Rock Mass Stability Criterion Based on Catastrophe Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Zhang Jixun ◽  
Shu Jiaqing ◽  
Zhang Haibo ◽  
Ren Xuhua ◽  
Qi Jiang
Keyword(s):  
Rock Mass ◽  
Stability Criterion ◽  
Catastrophe Theory ◽  
Reference Value ◽  
Engineering Practice ◽  
Mass System ◽  
Nonlinear Characteristics ◽  
Rock Mass Stability ◽  
Characteristic Values ◽  
The Stability

In rock mass engineering, the criterion of rock mass stability has complex nonlinear characteristics, so the process of instability for local rock mass system cannot be quantified by the traditional ways of displacement criterion and the criterion of development of plastic zones, which are strongly empirical. Based on the research about the criterion of rock mass stability, criterion of improved strain energy catastrophe is put forward by virtue of catastrophe theory in this paper. After regularizing potential function, the stability of the system can be determined by catastrophe characteristic values. Take a certain slope for example; the results show that the criterion can quantitatively reflect the behavioral process of instability for rock mass system, which is consistent with the engineering practice and possesses a certain engineering reference value.

Judgement Method for Surrounding Rock Stability of Guanjiao Tunnel Based on Catastrophe Theory

2011 ◽  
Vol 90-93 ◽  
pp. 2307-2312 ◽  
Author(s):  
Wen Jiang Li ◽  
Su Min Zhang ◽  
Xian Min Han
Keyword(s):  
Plastic Strain ◽  
Catastrophe Theory ◽  
Soft Rock ◽  
Surrounding Rock ◽  
In Situ Monitoring ◽  
Engineering Practice ◽  
Stability Of Surrounding Rock ◽  
The Stability ◽  
Rock Tunnel

The stability judgement of surrounding rock is one of the key jobs in tunnel engineering. Taking the Erlongdong fault bundle section of Guanjiao Tunnel as the background, the stability of surrounding rock during construction of soft rock tunnel was discussed preliminarily. Based on plastic strain catastrophe theory, and combining numerical results and in-situ data, the limit displacements for stability of surrounding rock were analyzed and obtained corresponding to the in-situ monitoring technology. It shows that the limit displacements obtained corresponds to engineering practice primarily. The plastic strain catastrophe theory under unloading condition provides new thought for ground stability of deep soft rock tunnel and can be good guidance and valuable reference to construction decision making and deformation managing of similar tunnels.

SYNCHRONIZATION OF DUAL HOMODROMY ROTORS WITH ECCENTRIC MASSES IN A NONLINEAR VIBRATING SYSTEM

2016 ◽  
Vol 40 (3) ◽  
pp. 303-315 ◽  
Author(s):  
Xueliang Zhang ◽  
Jinlin Xu ◽  
Chunyu Zhao ◽  
Bangchun Wen
Keyword(s):  
Phase Difference ◽  
Stability Criterion ◽  
Asymptotic Method ◽  
Resonant State ◽  
Nonlinear Stiffness ◽  
Theory Method ◽  
Nonlinear Characteristics ◽  
Motion Equations ◽  
Vibrating System ◽  
The Stability

The motion equations of a nonlinear vibrating system are given firstly. The nonlinear stiffness of springs is equivalently linearized as a function of the response of system by the asymptotic method. The synchronization criterion of dual homodromy rotors with eccentric masses is derived theoretically, as well as the stability criterion. It is shown that the phase difference is close to zero during a sub-resonant state, otherwise it approaches π. The nonlinear characteristics of system are discussed numerically. By the comparisons among theory, numeric and simulation, the validity of the theory method used is examined.

The Evaluation of Stability of Rock Mass Slope Based on the Block Theory and DDA Numerical

2013 ◽  
Vol 353-356 ◽  
pp. 1051-1056 ◽  
Author(s):  
Qiang Ma ◽  
Guang Jie Li ◽  
Yuan Hong
Keyword(s):  
Free Surface ◽  
Rock Mass ◽  
Large Scale ◽  
Vector Analysis ◽  
Analysis Method ◽  
Mass System ◽  
Block Theory ◽  
Long Period ◽  
Analysis Of Stability ◽  
The Stability

The instability of rock mass in a large scale is caused by the geological interaction and movement over a long period of time, of which rock mass system cut by structural plane and free surface. Firstly the block theory and Kinematics vector analysis are applied to program the analysis of stability in rock mass slope in order to be fully utilised in the pragmatic constructions. Through Matlab compilation to calculate out the movable blocks then by DDA analysis method to analyse the movable blocks inconsecutively. The resultant force of rock blocks and strain can be solved to measure the stability of rock blocks according to the results.

scholarly journals Analysis of the Deformation Characteristics of the Surrounding Rock Mass a Deep Tunnel during Excavation through a Fracture Zone

2021 ◽  
Author(s):  
Junhong Huang ◽  
Guang Zhang ◽  
Yi Luo ◽  
Shaohua Hu ◽  
Hangli Gong ◽  
...  
Keyword(s):  
Rock Mass ◽  
Fracture Zone ◽  
Inflection Point ◽  
Theoretical Research ◽  
Engineering Practice ◽  
Deformation And Failure ◽  
Deformation Curves ◽  
Advanced Support ◽  
The Stability ◽  
Double Track

Abstract Aiming at geological disasters triggered by fracture zones in surrounding rocks during the excavation of deep railway tunnels, the research investigated deformation and failure of surrounding rocks triggered by sudden changes of rock quality encountered in a tunnel excavation project. The research started from analysis of a field case: the Daliang Tunnel on the Gansu–Qinghai section of the Lanzhou-Urumuqi second double-track railway in China. The deformation profiles of surrounding rocks at different distances from the fracture zone was evaluated. The deformation of surrounding rocks in and around the fracture zone was studied by combining in-situ measurement, theoretical research, and numerical simulation. In addition, relationships of deformation of surrounding rocks in the section of the fracture zone with the materials and length of advanced support as well as the excavation footage behind the fracture zone were discussed. Analysis of the results showed that there is an inflection point on the deformation curves of surrounding rocks far ahead of the fracture zone; however, it is difficult to observe the inflection point on deformation curves of surrounding rocks in engineering practice as the rocks there have undergone substantial deformation before being exposed. A combination of material properties and length of advanced support is conducive to controlling the deformation of surrounding rocks in the fracture zone. Taking a rate of deformation of surrounding rocks in the fracture zone as less than 0.1 mm/d as the stability criterion, the excavated length of that rock mass behind the zone at a footage of 1 m/d is about two thirds of that at 2 m/d and half of that at 3 m/d when the deformation stabilizes.

scholarly journals Stability Assessment of Rock Mass System under Multiple Adjacent Structures

Systems ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Bo Sung Kim ◽  
Joon Kyu Lee
Keyword(s):  
Rock Mass ◽  
Numerical Solutions ◽  
Algebraic Expression ◽  
Mass System ◽  
Adjacent Structures ◽  
Mass Properties ◽  
Real Performance ◽  
The Stability ◽  
Strip Footings ◽  
Complicated Task

Numerical modeling is important for exploring the fundamental processes occurring in rock and for evaluating the real performance of structures built on and in rock mass system, and thus for supporting the design of rock engineering problems. Estimating the stability of rock mass foundation systems entirely based on a theoretical approach is a complicated task if there exists overlapping of their potential collapse modes. This paper applies finite element limit analysis to evaluate the bearing capacity of equally spaced multiple strip footings resting on rock mass obeying the modified non-linear Hoek–Brown failure criterion. Numerical solutions are expressed in terms of the efficiency factor that is dependent on the spacing between footings, as well as the rock mass properties. In addition, the effects of surface surcharge and footing roughness are quantified. The maximum spacing at which the interfering effect of adjacent footings becomes disappeared is evaluated and an algebraic expression for approximating the maximum spacing is proposed. Failure mechanisms for a few cases of rock mass under multiple strip footings are examined.

Analyze of the Affection of Excavation Unloading of the Rock Mass of the Spillway Tunnel of a Hydropower Station on the Slope’s Stability

2012 ◽  
Vol 594-597 ◽  
pp. 621-626 ◽  
Author(s):  
Le Hua Wang ◽  
Jun Lei Bai
Keyword(s):  
Rock Mass ◽  
Hydropower Station ◽  
Engineering Practice ◽  
Tunnel Face ◽  
Tunnel Excavation ◽  
Slope Rock ◽  
Spillway Tunnel ◽  
The Stability ◽  
Unloading Effect

After the excavation of the rock , the rock mass stress state changes and the quality of rock mass damage deterioration. Rock excavation of spillway tunnel of the hydropower station may have some influence on the stability of the tunnel-face side slope. In this paper, combined with the engineering practice, based on the unloading rock mass theory and through two dimensional finite-difference method. Selected seven feature points near the excavation surface as monitoring points for calculation ,then calculated the effect on the stress and strain of the slope caused by the excavation of the spillway tunnel and analysed the changes in the distribution of the slope rock mass plastic zone and the point factor of safety. The results show that spillway tunnel excavation in excavated slope have some impact on the excavated slope stability, and it is more obvious for the effect on stability of excavated slope in considering rock mass unloading effect than do not consider the rock mass unloading effect.

scholarly journals Subway Gearbox Fault Diagnosis Algorithm Based on Adaptive Spline Impact Suppression

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 660
Author(s):  
Zhongshuo Hu ◽  
Jianwei Yang ◽  
Dechen Yao ◽  
Jinhai Wang ◽  
Yongliang Bai
Keyword(s):  
Fault Diagnosis ◽  
Spline Interpolation ◽  
Reference Value ◽  
High Amplitude ◽  
Engineering Practice ◽  
Negative Effects ◽  
Short Term ◽  
Time Domain Signal ◽  
Gearbox Vibration ◽  
Long Time

In the signal processing of real subway vehicles, impacts between wheelsets and rail joint gaps have significant negative effects on the spectrum. This introduces great difficulties for the fault diagnosis of gearboxes. To solve this problem, this paper proposes an adaptive time-domain signal segmentation method that envelopes the original signal using a cubic spline interpolation. The peak values of the rail joint gap impacts are extracted to realize the adaptive segmentation of gearbox fault signals when the vehicle was moving at a uniform speed. A long-time and unsteady signal affected by wheel–rail impacts is segmented into multiple short-term, steady-state signals, which can suppress the high amplitude of the shock response signal. Finally, on this basis, multiple short-term sample signals are analyzed by time- and frequency-domain analyses and compared with the nonfaulty results. The results showed that the method can efficiently suppress the high-amplitude components of subway gearbox vibration signals and effectively extract the characteristics of weak faults due to uniform wear of the gearbox in the time and frequency domains. This provides reference value for the gearbox fault diagnosis in engineering practice.

scholarly journals Study on the Deformation Mechanism of Soft Rock Roadway under Blasting Disturbance in Baoguo Iron Mine

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hong-di Jing ◽  
Yuan-hui Li ◽  
Kun-meng Li
Keyword(s):  
Rock Mass ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Deformation Monitoring ◽  
Underground Mines ◽  
Blasting Vibration ◽  
Iron Mine ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to study the deformation mechanism of soft rock roadway in underground mines, it is necessary not only to study the influence of the dynamic disturbance caused by the cyclic mining blasting vibration on the stability of the soft rock roadway but also to study the degradation of the roadway surrounding rock itself and other factors. The paper presented a synthetic research system to investigate the factors that influence roadway rock structure deterioration in Baoguo Iron Mine. Firstly, the stability of rock mass was analyzed from the perspective of the physical and structural characteristics of the rock mass. Afterwards, according to monitoring data of mining blasting vibration, a suitable safety blasting prediction model for Baoguo Iron Mine was determined. And then, combining the results of mining blasting vibration monitoring and deformation monitoring, the effect of cyclic mining blasting on the stability of the soft rock roadway was obtained. By systematically studying the intrinsic factors of rock quality degradation and external environmental disturbances and their interactions, this paper comprehensively explores the deformation mechanism of soft rock roadway and provides the support for fundamentally solving the large deformation problems of soft rock roadway in underground mines.

Hydro-Mechanical Coupled Analysis of the Stability of Surrounding Rock Mass of Underground Water-Sealed Oil Storage

2013 ◽  
Vol 405-408 ◽  
pp. 402-405 ◽  
Author(s):  
Yun Jie Zhang ◽  
Tao Xu ◽  
Qiang Xu ◽  
Lin Bu
Keyword(s):  
Rock Mass ◽  
Underground Water ◽  
Surrounding Rock ◽  
Comsol Multiphysics ◽  
Coupled Analysis ◽  
Coupling Theory ◽  
Oil Storage ◽  
Stability Of Surrounding Rock ◽  
Straight Wall ◽  
The Stability

Based on the fluid-solid coupling theory, we study the stability of surrounding rock mass around underground oil storage in Huangdao, Shandong province, analyze the stress of the surrounding rock mass around three chambers and the displacement change of several key monitoring points after excavation and evaluate the stability of surrounding rock mass using COMSOL Multiphysics software. Research results show that the stress at both sides of the straight wall of cavern increases, especially obvious stress concentration forms at the corners of the cavern, and the surrounding rock mass moves towards the cavern after excavation. The stress and displacement of the surrounding rock mass will increase accordingly after setting the water curtains, but the change does not have a substantive impact on the stability of surrounding rock mass.

Design of Electrostatic Precipitator Power System Based on Auto Disturbance Rejection Controller

2013 ◽  
Vol 846-847 ◽  
pp. 190-194
Author(s):  
Shu Jun Yin ◽  
Xue Ren Li ◽  
Ji Geng Luo
Keyword(s):  
Power Supply ◽  
Disturbance Rejection ◽  
Power Supply System ◽  
Electrostatic Precipitator ◽  
Supply System ◽  
System Stability ◽  
Engineering Practice ◽  
Single Chip ◽  
High Voltage Power Supply ◽  
The Stability

The paper designs a three-phase high voltage power supply system based on active disturbance rejection controller which make single-chip microcomputer ATmega128 as the main control chip and the system improve the stability and control precision of dust removing power. Engineering practice shows that, the DC power supply system has the advantages of convenient operation, high work efficiency, system stability.

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