Study on the Smoke Evacuation and Safety-Evaluation of Oversized Shield Machine in Tunnel Drilling

2011 ◽  
Vol 94-96 ◽  
pp. 2226-2232
Author(s):  
Wei Min Wang
Keyword(s):  
Large Diameter ◽  
Safety Evaluation ◽  
Tunnel Construction ◽  
Fire Prevention ◽  
Basic Principles ◽  
Safety Measures ◽  
Tunnel Fires ◽  
Fire Scenarios ◽  
Smoke Evacuation ◽  
Shield Machine

Based on the data of the extra large diameter and extra distance of drilling of the Shanghai Yangtze Tunnel Highway, the paper introduces various fire scenarios under shield construction, and examines the distribution of various tunnel fires according to the actual circumstance of tunnel construction, patterns of smoke change of various fire circumstances; The thesis also provides significant measures and time for evacuation, and the features of fire expansion and smoke circulation in different fire situations, It compares fire expansion and smoke extension in different fire situations, analyzes patterns of fire expansion and smoke extension in different measures of fire prevention and their impact on the consequences of fire. Meanwhile, the thesis evaluates the effect of fire prevention, and explores some basic principles and safety measures for evacuating performance and fire rescue, crew safety and efficiency according to the temperature in the tunnel, pressure and smoke extension with fire

Impact of Double-O-Tube Shield Tunnel Construction on Grillage Beams Foundation Frame Building

2011 ◽  
Vol 71-78 ◽  
pp. 32-36 ◽  
Author(s):  
Xin Jiang Wei ◽  
Jie Hong ◽  
Gang Wei
Keyword(s):  
Principal Stress ◽  
Differential Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Foundation Settlement ◽  
Ground Settlement ◽  
Shield Tunneling ◽  
Frame Building ◽  
Shield Machine ◽  
The Impact

Considering the interaction of building-soil-tunnel, the grillage beams foundation frame building vertical crossed by Double-O-Tube (DOT) shield tunnel was simulated by 3D MIDAS/ GTS software, and the impact of construction on the building was analyzed. The results show that: the ground settlement trough caused by DOT shield tunnel can be fitted by peck formula; during the passage of the shield tunneling through the building, the settlement of the building increased and settlement trough was wilder; the settlement was stable and had a little rebound when shield machine already passed the building; with the increase of driving distance, the first principal stress P1 increased and then was stable; with the increase of L, the shape of foundation settlement curve changed, and the maximum differential settlement between columns increased but was small.

scholarly journals Analysis of Metal Fire Problems and Corresponding Safety Measures

2020 ◽  
Vol 20 (2) ◽  
pp. 79-87
Author(s):  
Euipyeong Lee
Keyword(s):  
Case Analysis ◽  
Waste Recycling ◽  
Fire Prevention ◽  
Fire Departments ◽  
Safety Measures ◽  
Response System ◽  
Prevention Activities

The problems and measures were analyzed through the case analysis of metal fire as there was not enough research on metal fire. The problems included ① not having metal fires in the classification of fires, ② the lack of safety measures, ③ not having grounds for the specified quantity of the hazard, ④ an inadequate interim treatment of waste recycling and inappropriate notification by the Ministry of Environment. And the measures included ① the enactment of a metal fire guideline, ② establishment of preparedness and response system of fire departments, ③ strengthening fire prevention activities, ④ review of reduction of specified quantity such as iron, magnesium, etc.

scholarly journals Analysis of the Problems and Safety Measures of Magnesium Fires

2020 ◽  
Vol 20 (2) ◽  
pp. 95-104
Author(s):  
Euipyeong Lee
Keyword(s):  
Research And Development ◽  
Safety Management ◽  
Case Analysis ◽  
Fire Fighting ◽  
Fire Prevention ◽  
Safety Measures ◽  
Fire Extinguishing

The problems and safety measures for magnesium fires were analyzed based on the fire case analysis in this study. The following problems were analyzed: ① the fire occurs in areas where there is no regulation under the Hazardous Goods Safety Management Act, ② the lack of safety measures during the firefighting of magnesium fires, ③ absence of adaptive fire fighting agents or equipment, ④ absence of suitable fire fighting tactics. For safety measures, the following were analyzed: ① enactment of magnesium fire guidelines, ② the education and publicity regarding fire prevention and countermeasures by fire organizations, ③ the obligation to have appropriate fire extinguishing agents in the places where magnesium is stored and handled, ④ the development of suppression equipment and fire fighting tactics, and ⑤ the research and development of fire extinguishing agents.

scholarly journals Fire Temperature Based on the Time and Resistance of Buildings—Predicting the Adoption of Fire Safety Measures

Fire ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 19 ◽  
Author(s):  
Luciano Santarpia ◽  
Simone Bologna ◽  
Virgilio Ciancio ◽  
Iacopo Golasi ◽  
Ferdinando Salata
Keyword(s):  
Heat Flux ◽  
Fire Risk ◽  
Fire Prevention ◽  
Time Interval ◽  
Fire Load ◽  
Safety Measures ◽  
Fire Temperature ◽  
Fire Risk Analysis ◽  
Opening Factor

During a fire in enclosed spaces, having structures with a good level of resistance is very important. The post flashover fire time interval, during which rescue squads operate, is important to verify if the structure can still resist fire for an acceptable time interval. This can be determined through the REI value. Hence, the way the fire develops must be examined together with the trend of the temperature that might guarantee that the structure will resist the heat flux released during the combustion. This article examines and compares, through a case study, the most important methods for analysis of the fire risk: the prescriptive approach and the simplified performance-based approach. The performance-based method (more suitable for the actual planning demand with respect to the more cautious prescriptive approach) is affected by the parameters influencing its development. The goal of this article is to provide a graph (based on parameters like the type of building, opening factor “O” and fire load “q”) that might be used by designers and architects to carry out the planning phase and adopt fire prevention systems before dealing with the assessments required by the engineering field for the fire risk analysis.

Evaluation of ground loss ratio with moving trajectories induced in double-O-tube (DOT) tunnelling

2018 ◽  
Vol 55 (6) ◽  
pp. 894-902 ◽  
Author(s):  
Dong-Jie Ren ◽  
Shui-Long Shen ◽  
Arul Arulrajah ◽  
Huai-Na Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Calculation Method ◽  
Tunnel Construction ◽  
Loss Ratio ◽  
Ground Settlement ◽  
The Finite Element Method ◽  
Shield Tunnelling ◽  
Ground Loss ◽  
Shield Machine

This paper investigates the influence of moving trajectories on ground loss ratio (GRL) due to the double-O-tube (DOT) tunnelling method. DOT tunnelling has three moving trajectories: pitching, yawing, and rolling, which have different behaviours during tunnel construction compared with those from single circular shield tunnelling. These moving trajectories cause overexcavation during tunnelling. The calculation method of gap area between the DOT shield machine and linings is evaluated in this research. Based on the superposition concept, the modification equation of GLR is proposed, which takes both moving trajectory and grouting volume into consideration. A field DOT tunnelling case is analysed to determine the correlation between moving trajectories and ground settlement. The influence of tail grouting is discussed by adjusting the grouting volume in different periods. The finite element method is also employed by setting the modified ground loss ratio (GLR′) as the contraction increment of linings. Results from both the measured and simulated settlements verify the reasonability of the proposed equation and the effect of moving trajectories on ground loss.

scholarly journals PEDESTRIAN SAFETY EVALUATION OF SIGNALIZED INTERSECTIONS USING SURROGATE SAFETY MEASURES

Transport ◽  
2020 ◽  
Vol 35 (1) ◽  
pp. 48-56
Author(s):  
Sankaran Marisamynathan ◽  
Perumal Vedagiri
Keyword(s):  
Safety Evaluation ◽  
Pedestrian Safety ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Mixed Traffic ◽  
Model Framework ◽  
Safety Measures ◽  
Severity Level ◽  
Traffic Conditions ◽  
Surrogate Safety Measures

The large proportions of pedestrian fatalities led researchers to make the improvements of pedestrian safety at intersections. Thus, this paper proposes a methodology to evaluate crosswalk safety at signalized intersections using Surrogate Safety Measures (SSM) under mixed traffic conditions. The required pedestrian, traffic, and geometric data were extracted based on the videographic survey conducted at signalized intersections in Mumbai (India). Post Encroachment Time (PET) for each pedestrian were segregated into three categories for estimating pedestrian–vehicle interactions and Cumulative Frequency Distribution (CDF) was plotted to calculate the threshold values for each interaction severity level. The Cumulative Logistic Regression (CLR) model was developed to predict the pedestrian mean PET values in the cross-walk at signalized intersections. The proposed model was validated with a new signalized intersection and the results were shown that the proposed PET ranges and model appropriate for Indian mixed traffic conditions. To assess the suitability of model framework, model transferability was carried out with data collected at signalized intersection in Kolkata (India). Finally, this study can be helpful to rank the severity level of pedestrian safety in the crosswalk and improve the existing facilities at signalized intersections.

scholarly journals Predictive Analysis of Settlement Risk in Tunnel Construction: A Bow-Tie-Bayesian Network Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Wen Liu ◽  
Shihong Zhai ◽  
Wenli Liu
Keyword(s):  
Bayesian Network ◽  
Surface Settlement ◽  
Test Theory ◽  
Predictive Analysis ◽  
Tunnel Construction ◽  
Occurrence Probability ◽  
Safety Measures ◽  
Expert Opinions ◽  
Key Nodes ◽  
Bow Tie

A hybrid method consisting of bow-tie-Bayesian network (BT-BN) analysis and fuzzy theory is proposed in this research, in order to support predictive analysis of settlement risk during shield tunnel excavation. We verified the method by running a probabilistic safety assessment (PSA) for a tunnel section in the Wuhan metro system. Firstly, we defined the “normal excavation phase” based on the fuzzy statistical test theory. We eliminated the noise records in the tunnel construction log and extracted the occurrence probability of facility failures from the denoised database. We then obtained the occurrence probability of environmental failures, operational errors, and multiple failures via aggregation of weighted expert opinions. The expert opinions were collected in the form of fuzzy numbers, including triangular numbers and trapezoidal numbers. Afterwards, we performed the BT-BN analysis. We mapped the bow-tie analysis to the Bayesian network and built a causal network PSA model consisting of 16 nodes. Causes of the excessive surface settlement and the resulting surface collapse were determined by bow-tie analysis. The key nodes of accidents were determined by introducing three key measures into the Bayesian inference. Finally, we described the safety measures for the key nodes based on the PSA results. These safety measures were capable of reducing the failure occurrence probability (in one year) of excessive surface settlement by 66%, thus lowering the accident probability caused by excessive surface settlement.

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