scholarly journals A Normal Cloud Model-Based Method for Risk Assessment of Water Inrush and Its Application in a Super-Long Tunnel Constructed by a Tunnel Boring Machine in the Arid Area of Northwest China

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 644 ◽  
Author(s):  
Xin Wang ◽  
Kebin Shi ◽  
Quan Shi ◽  
Hanwei Dong ◽  
Ming Chen
Keyword(s):  
Risk Assessment ◽  
Cloud Model ◽  
Water Inrush ◽  
Ideal Point ◽  
Tunnel Boring Machine ◽  
Northwest China ◽  
Arid Area ◽  
Dynamic Monitoring ◽  
Tunnel Boring ◽  
The Impact

Tunnel water inrush is complex, fuzzy, and random, and it is affected by many factors, such as hydrology, geology, and construction. However, few papers have considered the impact of dynamic monitoring on water inrush in previous research. In this study, considering geological, hydrological, and construction factors, as well as dynamic monitoring, a new multi-index evaluation method is proposed to analyze the risk of tunnel water inrush based on the normal cloud model. A new weight algorithm combining analytic hierarchy process and entropy method is used to calculate the index weight. The certainty degree of each evaluation index belonging to the corresponding cloud can be obtained by the cloud model theory. The final level of tunnel water inrush is determined via the synthetic certainty degree. The proposed method is applied to analyze the risk of water inrush in the SS (Shuang-san) tunnel constructed by a tunnel boring machine in the arid area of Northwest China. The evaluation results are not only basically identical to the results calculated by the ideal point and gray relation projection methods, but also agree well with the actual excavation results. This demonstrates that this new risk assessment method of water inrush has high accuracy and feasibility. Simultaneously, it also provides a new research idea to analyze the probability of tunnel water inrush and can provide a reference for related projects.

Human-Water Relationship Evaluation Based on Cloud Model for Arid Area in Northwest China

2014 ◽  
Vol 1065-1069 ◽  
pp. 2942-2947
Author(s):  
Mei Wang ◽  
De Shan Tang ◽  
Wei Shan Hu ◽  
Yi Fan Bai
Keyword(s):  
Evaluation Method ◽  
Cloud Model ◽  
Water System ◽  
Northwest China ◽  
Arid Area ◽  
Three Dimensions ◽  
Evaluation Index ◽  
Entropy Weight ◽  
Evaluation Indexes ◽  
Entropy Weight Method

Human-water relationship evaluation method based on cloud model is put forward to cope with the vagueness in evaluation language. With the intensive study of the specialty in human-water relationship in Northwest China arid area, three dimensions related to human-water relationship, natural water cycle’s health degree (NWHD), Social water cycle’s rationality degree (SWRD) and human-to-water fitness degree (HWFD) are selected to describe the harmony degree between water system and human system. The limit of evaluation index subordinate to each dimension corresponding to every harmony level is determined, and thus we can generate a comprehensive cloud model with evaluation index harmony level. When numeric values substitute for basic evaluation indexes, combined with the weights calculated from entropy weight method and AHP method, we get the certainty distributions of dimension indexes and integration objects among each harmony level. Case shows that human-water relationship evaluation method based on cloud model can effectively solve the vagueness and uncertainty in evaluation language. The evaluation results reflect the harmony degree in Northwest China arid area precisely.

scholarly journals Ground subsidence due to the backfill pressure in tunnel boring machine

2020 ◽  
Vol 382 ◽  
pp. 19-24
Author(s):  
Chang-Kyun Ahn ◽  
Seok-Won Lee
Keyword(s):  
Ground Cover ◽  
Tunnel Boring Machine ◽  
Ground Subsidence ◽  
Design Stage ◽  
Shield Tunnel ◽  
Underground Structures ◽  
Tunnel Boring ◽  
Backfill Pressure ◽  
Ground Conditions ◽  
The Impact

Abstract. In shield tunnel boring machine constructions, backfill pressure affects surface settlement and the stability of other underground structures nearby. Therefore, it is essential to pre-calculate backfill pressure in the design stage. This study examines and compares the seven internationally known backfill pressure calculation theories and calculates and analyzes the backfill pressures in six virtual ground conditions. The calculated backfill pressure increased as the ground cover increased, but the increase rate decreased. Also, this study performs a numerical analysis to identify the impact on ground settlement and tunnel crown settlement. In the end, settlement was more impacted by face pressure than backfill pressure in the unsaturated and saturated ground conditions. Also, as the ground cover increased, the impact of backfill pressure decreased, and as the applied face pressure decreased, the impact of backfill pressure increased.

The Influence of Front Support on Vibration Behaviors of TBM Cutterhead under Impact Heavy Loads

2014 ◽  
Vol 541-542 ◽  
pp. 641-644
Author(s):  
Jun Zhou Huo ◽  
Xiang Yu Ouyang ◽  
Xu Zhang ◽  
Jing Chen
Keyword(s):  
Thrust Force ◽  
Translational Motion ◽  
Tunnel Boring Machine ◽  
Dynamics Simulation ◽  
Body System ◽  
Stabilization Time ◽  
Tunnel Boring ◽  
Heavy Loads ◽  
Multi Body ◽  
The Impact

Cutterhead is one of the key parts of Tunnel Boring Machine, TBM. The performance of cutterhead has a great impact on the boring capability of TBM. The impact heavy torque and thrust force bore by cutterhead during the tunneling process will cause severe vibration and lead to decline in its life even broken, which affect the boring efficiency. In this paper, a TBM mainframe model of Northwest Liaoning project has been built based on the multi-body system dynamics simulation platform ADAMS. It also has been discussed in the paper that the influence of front support on the vibration characteristics of cutterhead. The simulation results show that the front support will improve the vibration behaviors of cutterhead: The stabilization time of rotational and translational motion decreases 90% and 10% at least, the axial amplitude decreases 8%. All these conclusions have demonstrated that front support should be adopted when designing the TBM.

scholarly journals Risk assessment of water inrush in tunnel through water-rich fault based on AHP-Cloud model

2020 ◽  
Vol 11 (1) ◽  
pp. 301-317 ◽  
Author(s):  
Yaxiong Peng ◽  
Li Wu ◽  
Qingjun Zuo ◽  
Chunhui Chen ◽  
Yong Hao
Keyword(s):  
Risk Assessment ◽  
Cloud Model ◽  
Water Inrush

scholarly journals The Comprehensive Identification of Roof Risk in a Fully Mechanized Working Face Using the Cloud Model

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2072
Author(s):  
Yu Xiong ◽  
Dezhong Kong ◽  
Zhanbo Cheng ◽  
Guiyi Wu ◽  
Qi Zhang
Keyword(s):  
Risk Assessment ◽  
Influencing Factors ◽  
Risk Evaluation ◽  
Cloud Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Separation Distance ◽  
Accident Risk ◽  
Similarity Degree ◽  
Geological Conditions ◽  
The Impact

Roof accidents seriously affect the safe and efficient mining of the working faces. Therefore, it is necessary to assess and identify the possible and influencing factors on the occurrence of roof risk in a fully mechanized mining workface. In this study, based on the analytic hierarchy process and fuzzy comprehensive evaluation, a comprehensive standard cloud model was established through constructing a quantitative grade interval and calculating the weight of each index to achieve the aim of a roof risk assessment and identification. The accuracy of risk assessment was ensured by using the comprehensive analyses of various aspects, such as cloud digital features, risk assessment cloud image and standard cloud image. This showed that the main influencing factors on the occurrence of roof accidents were roof separation distance, weighting intensity and rib spalling followed by the coal body stress concentration, initial support force and geological conditions. Taking 42,115 fully mechanized working faces in the Yushen coal mining area as an engineering background, this model was adopted to assess and identify the risk of roof accidents through generating comprehensive assessment cloud images and introducing the Dice coefficient to calculate the similarity degree. The results showed that the overall risk of roof accidents in 42,115 working faces was regarded as grade II (general risk) through the overall index of comprehensive risk evaluation and a similarity degree of 0.8606. The impact of roof condition was mainly influenced by the risk of roof accidents, while the support status, personal working status and coal body condition had a limited effect on the risk of roof accidents. The comprehensive standard cloud model proposed in this study had strong visibility and discovered the key parts of risk indexes easily to solve the problems of ambiguity and quantitative identification in traditional roof risk evaluation methods. Therefore, this model was worth promoting, because it laid the foundation for the intelligent identification and early warning system of roof accident risk in a fully mechanized mining workface.

Risk assessment of water inrush in karst tunnels excavation based on normal cloud model

2018 ◽  
Vol 78 (5) ◽  
pp. 3783-3798 ◽  
Author(s):  
Xintong Wang ◽  
Shucai Li ◽  
Zhenhao Xu ◽  
Jie Hu ◽  
Dongdong Pan ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Cloud Model ◽  
Water Inrush

scholarly journals Risk Assessment of Water Inrush in Karst Tunnels Based on the Ideal Point Method

2018 ◽  
Vol 28 (2) ◽  
pp. 901-911 ◽  
Author(s):  
Yingchao Wang ◽  
C. Guney Olgun ◽  
Linbing Wang ◽  
Bo Meng
Keyword(s):  
Risk Assessment ◽  
Water Inrush ◽  
Ideal Point ◽  
Point Method ◽  
The Ideal
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