محمدحسن صداق

The main goal of this research was to assess the criteria pertaining to delays in infrastructure projects of Bushehr Water and Sewerage Company. Assessments were conducted by library studies, interviews, and questionnaires. The relating factors were provided to the statistical population in the form of a questionnaire. Subsequently, using the fuzzy TOPSIS method, the most effective factors were calculated and then the factors were introduced by degree of effectiveness. The statistical population of this research was divided into three categories with different responsibilities, characteristics, and perspectives as follows: Consulting engineers, Contracting companies, and Employer. Purposeful and available sampling method was used to determine the sample size and 30 persons were considered as the statistical sample. In this study, the factors influencing water and sewage project delays were identified in four categories of factors caused by financial issues, resources and materials, manpower management, and the knowledge and experience of the contractor, as well as 28 sub-criteria. Ranking factors effective in Bushehr water and sewage project delays indicated that the most important ones of these factors by importance respectively are: Failure to pay the contractor's claims on time; Inefficient manpower management and poor quality of work performed by the contractor; Lack of pricing by contractors to win the tender; Weak history or low number of contractor's technical and executive personnel; and Poor work planning due to inexperienced contractor.

Todays due to expansion of population and industry, the collection and storage of liquids has been paid attention more and more. Saving oil and chemical liquids require great care to maintain it. One of the most important and commonly structures for storing liquids is steel cylindrical above ground tanks. On the other hand, due to damage of tanks in past earthquakes, they persuade scientists to better understand the seismic behavior.As a consequence, this research has been studied examines the phenomenon of buckling under Bam, Golbaf, Firuzabad, Bojnurd, Manjil, Tabas and Sarein eartquakes with regard to the fluid and structure interaction. Tanks were selected with ratio of 0.5, 1.0, 1.5 and 2.0 with fixed and variable thickness in full mode. These Cases were analyzed with non-linear time history analysis by ABAQUS Software.Finally, Compare the results with American petroleum institute regulation (API), Iranian seismic design code for oil industries and forces show, both height and diameter increase to growth the risk of Elastoplastic buckling and also by increasing the height to diameter ratio reduces the risk of Elastoplastic Buckling. The amount of this damage has declined by increasing shell thickness and in the same vein designing these structure by define standards is not safe method.