scholarly journals Trajectory Analysis and Risk Evaluation of Dangerous Rock Mass Instability of an Overhang Slope, Southwest of China

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wen-lian Liu ◽  
Jia-xing Dong ◽  
Han-hua Xu ◽  
Su-gang Sui ◽  
Run-xue Yang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Risk Evaluation ◽  
Simulation Analysis ◽  
Risk Level ◽  
Movement Trajectory ◽  
High Slope ◽  
Medium Risk ◽  
Movement Distance ◽  
Evaluation Matrix ◽  
Dangerous Rock Mass

Analysis of the movement trajectory and risk assessment of the high-slope dangerous rock mass collapse are of great significance for preventing and controlling the geological disasters of collapse. This study firstly takes the dangerous rock mass of the high slope in Pu’erdu Town, Yanjin County, Zhaotong City, Yunnan Province, as the research object, calculates and analyzes the trajectory of collapse movement of several groups of dangerous rock mass with great threat, and RocFall are used to carry out numerical simulation analysis and verification. Secondly, the risk and vulnerability of the dangerous rock mass in the study area are analyzed, and the risk evaluation is carried out through the risk evaluation matrix to clearly define the risk level. Results show that if the dangerous rock mass collapses, the horizontal movement distance was approximately 53–88 m, and the maximum bounce height of the platform was approximately 3–18 m, which will seriously threaten the life and property safety of residents. There is little difference between the simulation of the collapse of dangerous rock mass by RocFall software and the calculation result of the formula. Although RocFall software is more intuitive and can be directly compared with charts, software cannot completely simulate the actual situation, and it is only suggested as a reference from design rather than a basis of design. The result of risk evaluation shows that there are 2 high-risk dangerous rocks, 3 medium-risk dangerous rocks, and 1 low-risk dangerous rock in this area. It is suggested that a reasonable and scientific engineering treatment scheme should be put forward as soon as possible in combination with the collapse trajectory of the collapsing movement.

Risk Analysis on the Accident of TBM’s Cutterhead Jamming Caused by Collapse of Tunnel

2012 ◽  
Vol 446-449 ◽  
pp. 2246-2250 ◽  
Author(s):  
Sen Wen ◽  
Han Zhou Liu ◽  
Li Min Zhao
Keyword(s):  
Probability Theory ◽  
Rock Mass ◽  
Risk Analysis ◽  
Risk Evaluation ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Resistance Torque ◽  
Practical Engineering ◽  
Evaluation Matrix ◽  
The Relationship

If TBM does the excavating work in jointed rock mass, the cutterhead may be jammed. In order to decrease the loss, it is necessary to carry out risk evaluation. Whether the cutterhead is jammed or not depends on the relationship between torque and resistance torque. The magnitude of resistance torque depends on height of collapse, so according to the randomicity of height of collapse and probability theory, a formula for calculating the probability of cutterhead jamming is established. Meanwhile, according to the magnitude of resistance torque and cutterhead’s parameters, consequence of cutterhead jamming is divided into five ranks. Based on probability and consequence ranks, risk evaluation matrix for TBM’s cutterhead is proposed. The research results are demonstrated logically by the calculation of practical engineering.

scholarly journals Biological risk assessment: A challenge for occupational health and safety practitioners during the COVID-19 (SARS-CoV-2) Pandemic

Work ◽  
2021 ◽  
pp. 1-11
Author(s):  
Carlos Carvalhais ◽  
Micaela Querido ◽  
Cristiana C. Pereira ◽  
Joana Santos
Keyword(s):  
Risk Assessment ◽  
Occupational Safety ◽  
Assessment Method ◽  
Occupational Safety And Health ◽  
Risk Level ◽  
Biological Risk ◽  
Occupational Risks ◽  
Qualitative Risk Assessment ◽  
Safety And Health ◽  
Medium Risk

BACKGROUND: The COVID-19 global pandemic brought several challenges to occupational safety and health practice. One of these is the need to (re)assess the occupational risks, particularly, biological risks. OBJECTIVE: The purpose of this work is to promote guidance to occupational safety and health practitioners when conducting a biological risk assessment in this context. METHODS: The main steps of the biological risk assessment are explained with some inputs regarding the novelty posed by SARS-CoV-2 and an example of a qualitative risk assessment method is presented. Also, its application to two different activities was exemplified. RESULTS: In both cases, the assessment considered that vulnerable workers were working from home or in medical leave. The results showed low or medium risk level for the assessed tasks. For medium risk level, additional controls are advised, such maintain social distancing, sanitize instruments/equipment before use, use proper and well-maintained PPE (when applicable), and promote awareness sessions to spread good practices at work. Employers must be aware of their obligations regarding biological risk assessment and OSH practitioners must be prepared to screen and link the abundance of scientific evidence generated following the outbreak, with the technical practice. CONCLUSIONS: This paper could be an important contribution to OSH practice since it highlights the need to (re)assess occupational risks, especially biological risk, to ensure a safe return to work, providing technical guidance.

scholarly journals Numerical Simulation on Large Deformation of Weak Rock Mass Tunnel Under High Geostress

2018 ◽  
Vol 175 ◽  
pp. 03025
Author(s):  
Feng Zhou ◽  
Hongjian Jiang ◽  
Xiaorui Wang
Keyword(s):  
Rock Mass ◽  
Large Deformation ◽  
Lateral Pressure ◽  
Simulation Analysis ◽  
Pressure Coefficient ◽  
Surrounding Rock ◽  
Analog Simulation ◽  
Lateral Pressure Coefficient ◽  
High Geostress ◽  
The Stability

The problem about the stability of tunnel surrounding rock is always an important research object of geotechnical engineering, and the right or wrong of the result from stability analysis on surrounding rock is related to success or failure of an underground project. In order to study the deformation rules of weak surrounding rock along with lateral pressure coefficient and burying depth varying under high geostress and discuss the dynamic variation trend of surrounding rock, the paper based on the application of finite difference software of FLAC3D, which can describe large deformation character of rock mass, analog simulation analysis of surrounding rock typical section of the class II was proceeded. Some conclusions were drawn as follows: (1) when burying depth is invariable, the displacements of tunnel surrounding rock have a trend of increasing first and then decreasing along with increasing of lateral pressure coefficient. The floor heave is the most sensitive to change of lateral pressure coefficient. The horizontal convergence takes second place. The vault subsidence is feeblish to change of lateral pressure coefficient. (2) The displacements of tunnel surrounding rock have some extend increase along with increasing of burying depth. The research conclusions are very effective in analyzing the stability of surrounding rock of Yunling tunnel. These are going to be a reference to tunnel supporting design and construction.

scholarly journals Risk Level Assessment in Construction Projects Using the Schedule Performance Index

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Roberto Barbosa dos Santos ◽  
Antônio Edésio Jungles
Keyword(s):  
Performance Index ◽  
Risk Evaluation ◽  
Construction Projects ◽  
Construction Project ◽  
Risk Level ◽  
Limit Values ◽  
Strong Point ◽  
Efficient Management ◽  
Schedule Performance ◽  
Inferior Limit

Construction projects are risky in both physical implementation and management. The characteristics of the risk reinforce the necessity of efficient management to increase the chances of success without commitment to its goals. This study explores the correlation of delay and the schedule performance index (SPI) to evaluate the risk of a construction project completed with time overruns. The hypothesis that the SPI of projects with a delay is distinct from those projects without a delay is assumed. A database with 19 elements was used to test this hypothesis and to calculate limit values to the SPI. Therefore, the risk of delay will be small when the observed SPI is greater than the superior limit and large when the SPI is below the inferior limit. The simplicity involved in the calculation of these values showed an advantage in comparison with other methods of risk evaluation. Another strong point observed is that any company can determine the value of risk by considering its own history and support decisions like doing corrective actions.

The Dangerous Rock Mass Deformation Analysis with Application of Kalman Filter Method Based on Material Properties and AR Model

2013 ◽  
Vol 738 ◽  
pp. 109-112
Author(s):  
Fu Min Lu ◽  
Ting Yao Jiang
Keyword(s):  
Kalman Filter ◽  
Rock Mass ◽  
Ar Model ◽  
Deformation Analysis ◽  
Filter Method ◽  
The Status ◽  
Rock Mass Deformation ◽  
Kalman Filter Method ◽  
Mass Deformation ◽  
Dangerous Rock Mass

Considering the material property of the rock to the dangerous rock mass,the paper Looks the model parameter of AR( 1) model as the status vector, and uses Kalman filter method to analysis the deformation of the dangerous rock mass. The result shows that the method can improve the accuracy of fitting and forecasting of the model.

Stability Analysis and Control Measures of the Kim-Yun-Mine Collapse

2012 ◽  
Vol 594-597 ◽  
pp. 358-361
Author(s):  
Shan Shan Zhang ◽  
Yu Liang Wu
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Stereographic Projection ◽  
Control Measures ◽  
Collapse Characteristics ◽  
Basic Characteristics ◽  
The Stability ◽  
Mine Collapse ◽  
And Control ◽  
Dangerous Rock Mass

Collapse is one of the major geological disasters all over the world and threats to life and property safety of people. To make a better understanding of the reason it occurs and how to deal with it, the Kim-Yun-Mine collapse is researched. There are one dangerous rock mass and two collapse accumulation body. The basic characteristics of the collapse is described clearly according to the geological exploration data, and the stability of the dangerous rock mass and the collapse accumulated body is analyzed in the way of engineering geology and stereographic projection. At last, we put forward comprehensive control measures based on the results of stability analysis and collapse characteristics.

Risk Evaluation in the Insurance Company Using REFII Model

2015 ◽  
pp. 748-768
Author(s):  
Goran Klepac
Keyword(s):  
Risk Factors ◽  
Data Mining ◽  
Time Series ◽  
Risk Evaluation ◽  
Time Series Data ◽  
Business Case ◽  
Risk Level ◽  
Insurance Company ◽  
Market Situation ◽  
Using Data

A business case describes a problem present in all insurance companies: portfolio risk evaluation. Such analysis deals with determining the risk level as well as main risk factors. In the specific case, an insurance company is faced with market share growth and profit decline. Discovered knowledge about the level of risk and main risk factors was not used to increase premium for the riskiest portfolio segments due to a specific market situation, which could lead to loss of clients in the long run. Instead, additional analysis was conducted using data mining methods resulting in a solution, which stopped further profit decline and lowered the risk level for the riskiest portfolio segments. The central role for the unexpected revealed knowledge in the chapter acts as the REFII model. The REFII model is an authorial mathematical model for time series data mining. The main purpose of that model is to automate time series analysis, through a unique transformation model of time series.

scholarly journals Simulation Analysis of Knee Ligaments in the Landing Phase of Freestyle Skiing Aerial

2019 ◽  
Vol 9 (18) ◽  
pp. 3713 ◽  
Author(s):  
Yanming Fu ◽  
Xin Wang ◽  
Tianbiao Yu
Keyword(s):  
Knee Joint ◽  
Mechanical Response ◽  
Simulation Analysis ◽  
Cruciate Ligament ◽  
Knee Injuries ◽  
Element Model ◽  
Knee Joints ◽  
Internal Stresses ◽  
Risk Of Injury ◽  
Medium Risk

The risk of knee injuries in freestyle skiing athletes that perform aerials is high. The internal stresses in the knee joints of these athletes cannot easily be directly measured. In order to ascertain the mechanical response of knee joints during the landing phase, and to explore the mechanism of damage to the cartilage and ligaments, a finite element model of the knee joint was established. Three successful landing conditions (neutral, backward, or forward landing) from a triple kicker were analyzed. The results demonstrate that the risk of cruciate ligament damage during a neutral landing was lowest. A forward landing carried medium risk, while backward landing was of highest risk. Backward and forward landing carried risk of injury to the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), respectively. The magnitude of stress on the meniscus and cartilage varied for all three landing scenarios. Stress was largest during neutral landing and least in backward landing, while forward landing resulted in a medium level of stress. The results also provide the basis for training that is scientifically robust so as to reduce the risk of injury and assist in the development of a professional knee joint protector.

Comparative Analysis of Neural Network and Fuzzy Logic Techniques in Credit Risk Evaluation

2016 ◽  
Vol 12 (1) ◽  
pp. 47-62 ◽  
Author(s):  
Asogbon Mojisola Grace ◽  
Samuel Oluwarotimi Williams
Keyword(s):  
Neural Network ◽  
Fuzzy Logic ◽  
Comparative Analysis ◽  
Credit Risk ◽  
Risk Evaluation ◽  
Fuzzy Inference ◽  
Learning Algorithm ◽  
Risk Level ◽  
Inference System ◽  
Wrong Decision

Credit risk evaluation techniques that aid effective decisions in credit lending are of great importance to the financial and banking industries. Such techniques assist credit managers to minimize the risks often associated with wrong decision making. Several techniques have been developed in the time past for credit risk evaluation and these techniques suffer from one form of limitation or the other. Recently, powerful soft computing tools have been proposed for problem solving among which are the neural networks and fuzzy logic. In this study, a neural network based on backpropagation learning algorithm and a fuzzy inference system based on Mamdani model were developed to evaluate the risk level of credit applicants. A comparative analysis of the performances of both systems was carried out and experimental results show that neural network with an overall prediction accuracy of 96.89% performed better than the fuzzy logic method with 94.44%. Finding from this study could provide useful information on how to improve the performance of existing credit risk evaluation systems.

Risk-Based Inspection Analysis for High Pressure Hydrogenation Cracking Unit

2006 ◽  
Author(s):  
Jian-Ping Zhao
Keyword(s):  
High Pressure ◽  
High Risk ◽  
Risk Level ◽  
Aromatic Plant ◽  
Inspection Plan ◽  
Medium Risk ◽  
Quantitative Analysis Method ◽  
Equipment Unit ◽  
Risk Situation ◽  
Risk Grade

High pressure hydrogenation cracking unit is the core equipment system in the aromatic plant, which is subjected simultaneously to the action of hydrogen and high pressure and high temperature. In this paper, quantitative analysis method of RBI was carried out by Orbit-Onshore software, which was developed by DNV corporation. In API 581, the risk situation for a certain equipment unit were classified into four grades, such as low risk grade and medium risk grade and medium-high risk grade and high grade, which is expressed as risk matrix. The whole risk distribution of 553 equipment and piping items was obtained, and in which the hydrocracking reactors and the reactor effluent air coolers are belong to ‘medium-high risk’ grade. Based on the RBI results, an optimum inspection plan was developed by the author to reduce the risk level for the hydrogenation cracking unit. It is concluded that the optimum inspection plan was completely satisfied with the engineering specification of the aromatic plant, after the validation of the inspection activity in 2004.

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