Geological Risk in Tunneling: the Example of Teheran Underground (original) (raw)
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The combined method for assessing risk factors in underground construction
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 2020
Purpose. Development of a combined method for qualitative and quantitative assessment of risk factors accompanying the construction and operation of underground constructions based on expert analysis and mathematical modeling by numerical methods. Methodology. When creating a comprehensive method for ranking the underground construction route by the degree of prob lems, we used methods of expert assessment, statistical analysis and mathematical modeling, which allow us to assess the state of each section by summing the points of risk factors assessment. findings. Based on the results of practical application of the developed method for ranking the Almaty metro route sections by the degree of problems, the method has shown its effectiveness in solving the problems of ensuring the safety of construction and operation of the metro and has been adopted for implementation. originality. Assessment of the condition of the underground construction route section according to the degree of problematic ity in accordance with the principle of adding risk factors through conditional points established by the results of expert analysis and mathematical modeling. Practical value. The method improves the effectiveness of monitoring the state of the underground construction route, im proves the quality of situational control as well as the forecast of the manifestation of risk situations and their development. The method can be used for solving similar problems in underground construction of different objects, including the development of mineral deposits.
Risk evaluation in tunneling excavation methods
REM - International Engineering Journal, 2018
Risk management is of paramount importance for the success of tunneling works and it is linked to the main excavation methods used: the Conventional Excavation Method (CEM) and the Tunnel Boring Machine Method (TBM). Considering the importance of the "Safety and Health" criterion for the choice of the excavation method, the fact that this criterion is usually mostly focused on the structural component, and taking in account that there is no research showing the advantages of one of the methods over the other, this research intends to conduct a comparative risk analysis between both methods, taking into consideration the different constraints that might appear. In order for this comparison to hold true, a risk evaluation is presented, analysing 12 risks and 4 risk factors in 3 phases, so that the impact of the different variables can really be appraised. This research is made in a scenario of the construction of a 3.5 km-long tunnel in a non-urban area, with an unproblematic rock mass. The final result will be a detailed analysis of the influence of "Safety and Health" criteria, useful for both the technical and the scientific community, something that has never been done before.
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Proceedings of the Eleventh International Conference on Computational Structures Technology, 2012
This paper covers the topic of tunnel risk assessment in general. It shows that by application of appropriate statistical and numerical models it is not only possible to demonstrate that the required safety level can be reached but also to compare the risk level of different designs in a relative approach. In the first section the background of tunnel risk assessment is presented to give a basic understanding of the issue followed by a description of requirements and applicable methods for the calculation of expected risk values. Finally the application of the methodology in the upgrading process of Učka tunnel is presented.
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Unexpected ground conditions have always been a major problem for the tunnelling industry. As demand for the development of new underground structures, regardless of the ground conditions, has increased, safety and risk considerations have become even more important. The methodology presented in this paper aims at the identification of risk-prone areas, incorporating, at the same time, the uncertainty of ground conditions. It is focused on TBM tunnelling and can be implemented in the early stages of the project. The methodology assesses the hazards by introducing the concept of a vulnerability index, which is based on the principles of rock engineering systems, to identify the weighting of the parameters, and on probabilistic modelling to address the uncertainty in the parameters' values. The proposed model is illustrated via the Athens Metro case study, used also for validating its performance under actual construction conditions.
Geotechnical Hazard Identification of Underground Excavation
International Paper of Geotechnical, 2020
Underground excavation is highly dangerous environment and risky condition. Geological and geotechnical condition are one of the factor that influence the excavation condition. It requires good methodology approach and well planned to respond the risk. This paper will discuss about the geotechnical methods that approach to identifying and understanding hazard that occurs in underground Excavation. Geotechnical hazard need to be recognized before, during and after the excavation. Author use the drilling data, seismic data and ground movement indicator to identify the geotechnical hazard. The Drill core from drilling data will be identified using Geology strength index (marinos, 2000) combined with point load test to recognized the ground condition before the excavation. The seismic device will show the ground respond from the excavation blasting or opening. The tunnel transformation will be observed using ground movement indicator device to identify the geotechnical problem after the excavation. In the end, geotechnical information analysis is conducted to decrease the risk in term of economy or work safe, also give time to face impending Geotechnical Hazard condition.
A Review on Methods of Predicting Tunneling Induced Ground Settlements
The purpose of this review paper is to present the techniques, approaches and methods for assessing the ground settlements induced by tunneling. Tunneling operation poses threat to adjacent structures by creating subsidence, heave, and vibrations which make the structure more vulnerable. With the advent of urbanization and innovative technologies, utilizing underground space is becoming a sustainable practice day by day. The assessment of ground settlement induced by tunneling is significant to policy makers, practitioners and designers associated with tunneling. The versatility of geological strata and condition has led the practice even more challenging. The multidimensional aspects and problems of tunnel applications has made the practice a complex one requiring incorporation of interdisciplinary nature of this study such as geology, civil engineering, mining engineering specially rock engineering and rock mechanics. This paper also addresses the issues regarding various methods, constitutive models, different ground conditions for instance, mixed faced soil and rock interface ground), roles effect of dimensions on analysis and prospects of multi and interdisciplinary roles.