A Bayesian belief network based delay risk assessment tool for tunnel projects – BBN tunnel

Download

index.pdf

Date

2019

Author

Köseoğlu Balta, Gülsüm Çağıl

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

187
views

98
downloads

Tunnel constructions are characterized by high degrees of uncertainty, due to two major factors; -geologic conditions, which can seldom be exactly known and -uncertainties in construction process itself as it highly depends on the performance of the equipment and workmanship. Therefore, due to the specific properties of tunnel construction projects, there is an increasing urgency to assess and manage the risks systematically. Initially, an extensive literature review was carried out to identify risks and proposed methods for risk identification in tunneling projects. Then, to gain insight into the practice of risk assessment of tunneling projects within the industry, current practices in a construction company are investigated and research needs are determined. In the light of these findings, major aims of the thesis are identified as; construction of a risk taxonomy that links risk with delay, development of a methodology for risk assessment and a tool that can be used to identify risk mitigation strategies to minimize delay. In collaboration with a construction company, first, major risk events, vulnerability and risk factors were determined, and a taxonomy was developed. Then, a dependency based probabilistic risk analysis method based on Bayesian Belief Networks (BBNs) was proposed. BBN model was developed and validated by utilizing several expert knowledge elicitation techniques. Finally, a decision support tool, BBN Tunnel, that can predict delay and estimate the cost-time impact of utilizing different strategies was developed. BBN Tunnel was tested, validated and its utilization in a real project was demonstrated by a case study. Results demonstrate that the methodology and tool may be used to integrate several risk factors, draw a comprehensive risk map, predict delay and help decision-makers to formulate risk management strategies to mitigate delay. .

Subject Keywords

Tunnels., Risk Assessment, Bayesian Belief Network, Tunnel Projects.

URI

http://etd.lib.metu.edu.tr/upload/12623220/index.pdf
https://hdl.handle.net/11511/43386

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

A RANDOM-FIELD MODEL FOR THE ESTIMATION OF SEISMIC HAZARD Yücemen, Mehmet Semih (Elsevier BV, 1993-10-01) A stochastic framework is developed, in terms of the theory of homogeneous random functions, to estimate the seismic hazard associated with linearly extending seismic sources. The formulation is carried out in the space-time domain. An earthquake having at least a magnitude of m is assumed to occur whenever the total strain energy accumulated over the potential rupture plane exceeds the energy level corresponding to this magnitude, m. An alternative formulation, in which an earthquake is generated when the ...
An efficient seismic intensity measure for seismic risk analysis of structures Çelik, Ozan Cem (null; 2010-12-01) In a seismic fragility or seismic margins assessment, the estimated structural system response is conditioned on a measure of seismic intensity. The U.S. Geological Survey currently stipulates the site-dependent seismic hazard by mapping the spectral acceleration at a frequency of 2% probability of being exceeded in 50 years. The scatter in structural responses at a given intensity measure (IM) due to record-to-record variability in ground motion ensembles used in nonlinear time history analysis of structur...
An alternative frame-shear wall model: continuum formulation KAZAZ, İLKER; Gulkan, Polat (Wiley, 2012-07-01) The basic assumption of the analysis of wall-frame structures is that two dissimilar structural systems, deforming in shear and flexural modes, are constrained to act together. The same set of boundary conditions is also assumed to be applicable to both types of components. An inconsistency arises when the rotation at the lower end of the combined beam is assumed to be zero because this boundary condition is applicable only to the flexural component of deformation. For the shear component that is related to...
An Investigation of seismic face stability of deep tunnels by using an axisymmetric finite element model Hadley, Hannah Elizabeth; Sucuoğlu, Haluk; Yılmaz, Mustafa Tolga; Department of Civil Engineering (2018) The static stability of tunnel faces has been widely studied, with the development of limit analysis and numerical modelling solutions. There has been limited research into seismic tunnel face stability. The aim of this study is to find the effect of seismic loading on tunnel face stability and suggest factors that could be used in design. A numerical model using the axisymmetric finite element method is developed to assess tunnel face stability under seismic loading. To verify the numerical analysis, it wa...
Modeling and implementation of local volatility surfaces in Bayesian framework Animoku, Abdulwahab; Uğur, Ömür; Yolcu-Okur, Yeliz (2018-06-01) In this study, we focus on the reconstruction of volatility surfaces via a Bayesian framework. Apart from classical methods, such as, parametric and non-parametric models, we study the Bayesian analysis of the (stochastically) parametrized volatility structure in Dupire local volatility model. We systematically develop and implement novel mathematical tools for handling the classical methods of constructing local volatility surfaces. The most critical limitation of the classical methods is obtaining negativ...

Citation Formats

G. Ç. Köseoğlu Balta, “A Bayesian belief network based delay risk assessment tool for tunnel projects – BBN tunnel,” Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Civil Engineering., Middle East Technical University, 2019.