Periodicals of Engineering and Natural Sciences ISSN 2303-4521 Vol. 8, No. 4, December 2020, pp.2525-2538 2525 Contribution of AHP method in prioritizing risk factors regarding tunnel project phases Ahmed Suad Ali 1 , Khalil Ismail Wali 2 1 Highway & Bridges Engineering Department, Erbil Technical Engineering College, Erbil Polytechnic University 2 Civil Engineering Department, College of Engineering, Salahuddin University ABSTRACT Tunnel projects are consistently regarded to be mostly a complex and risky engineering projects, owing to the features of the projects, since they increasingly achieve high risk and complexity during the execution of the project. this led to the fact that the necessity of risk management understanding and implementing is a crucial quest with the intention to obtain tunnel project objectives considering (time, cost, quality & safety) to avoid time and cost overruns and any other obstacles. it was observed the most affecting objective was Safety (47.3%) by AHP method in which it is actually reasonable as such project of tunnel need a great concern regarding that matter for many reasons for instance the closed construction area, ventilation considerations, blasting, and so on. the second major objective is quality (31.1%) in which as experts always say it has to be maintained as a high quality as possible. Keywords: Tunnel projects, AHP, Project Objectives, Risk Corresponding Author: Ahmed Suad Ali Highway & Bridges Engineering Department, Erbil Technical Engineering College Erbil Polytechnic University, Kurdistan Region, Iraq E-mail: ahmed.ali@epu.edu.iq; ahmedgeotech.2010@gmail.com 1. Introduction Tunnels are considered as a multidisciplinary construction, to be more precise; it is one of the massive infrastructures. Regarding that kind of construction, the need of a good quality management is a must; in order to achieve the main outcomes as much as possible, among those as the most are; time, cost, quality and safety. Tunneling as project recognized as complex pursue since they are obviously different than the usual on-ground structures and accordingly the design conditions change from a case to another. In other words, it is not simple to conduct such construction(tunnels) with such sophisticated details in any land type profile without a high uncertainty and eventually risk with in different phases [1]. Tunneling regarding the complicity of construction process on the most carry risks that would eventually affect such enormous parts of project outcomes among those time, cost, quality, safety. There are many tools and methods that simplify risk examinations. There are tools that concerned in qualitative and other quantitative methods in which it depends basically on the details of that project, and according to those details a suitable method can be chosen. Many ways available for the mean to follow and options and as a result to create what is known as risk analysis through the phases of any construction project, the right kind of risk analyzing method must be chosen among many of different methods and tools such as; event trees, sensitivity analysis or even though Monte Carlo Simulation [2]; decision-making frameworks such as AHP (analytic hierarchy process). While there are diverse risk types during any project, some of those are more common and have a high probability of occurrence. Thus, the probability of occurrence and their impact of any risk factor in preliminary are assessed and the overall risk score is accumulative of those risk factors. The Analytic Hierarchy framework (AHP) can be used as a method for what can called complex environments for decision making, such as tunnel construction projects, according to [3] AHP process can help brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Periodicals of Engineering and Natural Sciences (PEN - International University of...