Decision makers in the transportation industry search for a systematic approach to select an appropriate structural system, construction method, and material for bridges. Simple mathematical methodologies are needed to consider different stakeholders’ perspectives. With criteria that occur simultaneously in selecting appropriate material, construction technique, and structural system of bridges, invalid and unexpected results may occur from such complexity. The decision-making process is usually done subjectively by designers and requires much data and extensive experience in bridge design. To address these challenges and assume all substantial criteria within the framework, the PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluation) multi-criteria decision-making method is used. It is not sensitive to the number and definition of the criteria. The PROMETHEE method is based on the pairwise comparison between alternatives for constructing an outranking relationship to show the degree of dominance of one alternative over another. A case study of the Kashkhan Bridge in Iran is presented to demonstrate implementation of the PROMETHEE method and show how such a decision-making methodology can assist experts in making informed decisions based on a set of comprehensive criteria in the conceptual design stage. Some novel and effective criteria in this study are combined and synthesized to select the appropriate superstructure. Criteria weights and preference and indifference thresholds are collected through questionnaires filled out by bridge experts. Results of the case study show that the most appropriate system for the Kashkhan Bridge is the box girder system with the balanced cantilever method and posttensioned concrete material.

No abstract

PurposeMerging and updating project information and recording changes can give dynamic risk identification at all stages of the project. The main purpose of this research is to create an integration in construction information.Design/methodology/approachIn this research, the 5D model was prepared and then all model information was entered into the database designed in SQL Server, the project report tables were coded, and finally, a database with four groups of information was ready for risk identification.FindingsCreating an integrated risk identification platform reduced rework and time and cost control and change management, which were positive effects of risk identification at the right time.Research limitations/implicationsIn order to identify risks, creating multilateral databases whose information integration enables timely completion of the project and compliance with the planning.Practical implicationsThis research is the basis for identifying project risks within the framework of building information modeling and can be an effective contribution to increasing the risk-taking efficiency of the project.Originality/valueAs a matter of fact, marked time and cost are terrific motivating forces for the building industry, materializing with identify risk well-time. In any case, identifying risk engaged with all of the dimensions depend on this industry.

Purpose As the population grows, one of the major global crises is the management of human settlement. A proper solution to deal with this issue is mass housing. Given the variable needs in these projects, two constraints of height and volume of construction play an essential role in fulfilling success criteria. Hence, this paper aims to choose the most appropriate building method to satisfy time, cost, quality and safety factors considering the volume and height of construction. Design/methodology/approach In this research, the proper construction methods in mass housing projects in two volumes of up to 1000 (small) and 1000-3000 (medium) residential units in three ranges of the height of 5, 5-10, and higher than ten floors were determined with a focus on the success criteria based on real experiences through questionnaires and interviews. Findings The results show that steel bolt and nut and tunnel framework systems in higher than five-floor building projects act better than other methods, while in up to five-floor building projects, LSF saves time and cost and steel bolt and nut provides higher quality and safety. Originality/value Given the extent of work, the results of this research can be considered as a benchmark in the mass housing industry.

One of the recent innovations in developing countries has been taking advantage of private sector investment in setting up and managing infrastructure projects. In recent decades, these types of contracts are used extensively in developed countries with public-private partnership framework. Implementation and expansion of private partnerships in infrastructure projects results increase in investment and economical productivity. The paper purpose is to select the appropriate type of PPP contracts in financing railway projects in Iran benefiting from the decision making science and the expert opinions. The effect of criteria on selection method of financing railway project has been determined by using the questionnaire. Then the effect of criteria on financing method through partnerships (DBFO, BOT, BOO, Traditional PRI) has been assessed. Finally, suitable methods for financing rail projects are presented in order of preference, applying AHP methodology and Expert Choice software. 