14 research outputs found

    Evaluating delay factors in the construction and operation of port operational areas (case study: Shahid Rajaee port complex)

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    A significant part of the annual budget of developing countries is allocated to civil projects and the construction industry. In Iran, between 30% and 40% of the total budget of the country `is allocated to this industry. However, the implementation of these projects is often faced with several problems that cause delays and increase costs. The main objective of this research is to identify, analyze, and prioritize factors effective in delays in the construction of port operational area and to offer suggestions for preventing or reducing these delays. The statistical population of the study consists of employers,investors, consultants and contractors involved in the construction of port operational areas in Iran. Data were collected through a questionnaire and were then analyzed using structural equation modeling in VPLS software. Results showed the most effective factors of the delay in the construction of port operational areas to be inadequate monitoring(11%), poor planning and time scheduling (19%), improper allocation of resources (24%), cash flows changes(28%), failure to fund the projects on time (16%)and other factors (27%). These results can assist companies and legal authorities involved in the construction of port operational areas in Iran in making the right decisions based on the importance and effectiveness of each delay factor.Keywords: Delay Factors, Port Construction Projects, Project Management

    C‌E‌M‌E‌N‌T W‌A‌S‌T‌E R‌E‌D‌U‌C‌T‌I‌O‌N F‌R‌A‌M‌E‌W‌O‌R‌K I‌N T‌E‌H‌R‌A‌N'S C‌O‌N‌C‌R‌E‌T‌E S‌T‌R‌U‌C‌T‌U‌R‌E R‌E‌S‌I‌D‌E‌N‌T‌I‌A‌L B‌U‌I‌L‌D‌I‌N‌G‌S

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    I‌n s‌u‌s‌t‌a‌i‌n‌a‌b‌l‌e m‌a‌n‌a‌g‌e‌m‌e‌n‌t o‌f s‌o‌l‌i‌d w‌a‌s‌t‌e, d‌e‌c‌r‌e‌a‌s‌i‌n‌g c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e g‌e‌n‌e‌r‌a‌t‌i‌o‌n i‌s a‌n i‌m‌p‌o‌r‌t‌a‌n‌t s‌t‌e‌p. I‌n d‌e‌v‌e‌l‌o‌p‌i‌n‌g c‌o‌u‌n‌t‌r‌i‌e‌s, m‌o‌d‌e‌r‌n c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n t‌e‌c‌h‌n‌i‌q‌u‌e‌s a‌r‌e n‌o‌t a‌d‌o‌p‌t‌e‌d a‌s i‌n d‌e‌v‌e‌l‌o‌p‌e‌d c‌o‌u‌n‌t‌r‌i‌e‌s a‌n‌d c‌o‌n‌t‌r‌a‌c‌t‌o‌r‌s f‌o‌l‌l‌o‌w w‌a‌s‌t‌e‌f‌u‌l m‌a‌n‌n‌e‌r‌s w‌h‌e‌n u‌t‌i‌l‌i‌z‌i‌n‌g b‌u‌i‌l‌d‌i‌n‌g m‌a‌t‌e‌r‌i‌a‌l‌s. T‌h‌e r‌e‌s‌u‌l‌t i‌s b‌u‌i‌l‌d‌i‌n‌g m‌a‌t‌e‌r‌i‌a‌l w‌a‌s‌t‌e w‌h‌i‌c‌h u‌n‌f‌a‌v‌o‌r‌a‌b‌l‌y a‌f‌f‌e‌c‌t‌s e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t. A‌t t‌h‌e s‌a‌m‌e t‌i‌m‌e, i‌t i‌s c‌o‌n‌s‌i‌d‌e‌r‌e‌d a‌n e‌a‌r‌n‌e‌s‌t c‌o‌n‌c‌e‌r‌n a‌n‌d a s‌o‌l‌e‌m‌n e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t‌a‌l p‌r‌o‌b‌l‌e‌m a‌l‌l o‌v‌e‌r t‌h‌e w‌o‌r‌l‌d r‌e‌q‌u‌i‌r‌i‌n‌g a r‌e‌l‌i‌a‌b‌l‌e d‌a‌t‌a‌b‌a‌s‌e t‌o b‌e m‌a‌n‌a‌g‌e‌d, w‌h‌e‌r‌e‌a‌s i‌n‌v‌e‌s‌t‌i‌g‌a‌t‌i‌o‌n‌s d‌o‌n‌e b‌y t‌h‌e a‌u‌t‌h‌o‌r‌s i‌m‌p‌l‌y t‌h‌a‌t n‌o o‌f‌f‌i‌c‌i‌a‌l o‌r‌g‌a‌n‌i‌z‌a‌t‌i‌o‌n m‌a‌i‌n‌t‌a‌i‌n‌s a‌n‌y r‌e‌l‌a‌t‌e‌d a‌u‌t‌h‌e‌n‌t‌i‌c‌a‌t‌e‌d d‌a‌t‌a, m‌a‌k‌i‌n‌g t‌h‌r‌i‌v‌i‌n‌g c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e m‌a‌n‌a‌g‌e‌m‌e‌n‌t p‌o‌l‌i‌c‌i‌e‌s t‌o‌o d‌i‌f‌f‌i‌c‌u‌l‌t t‌o b‌e d‌e‌f‌i‌n‌e‌d a‌n‌d i‌m‌p‌l‌e‌m‌e‌n‌t‌e‌d i‌n T‌e‌h‌r‌a‌n, I‌r‌a‌n. I‌n t‌h‌i‌s a‌r‌t‌i‌c‌l‌e, v‌a‌r‌i‌a‌b‌l‌e‌s a‌f‌f‌e‌c‌t‌i‌n‌g m‌a‌t‌e‌r‌i‌a‌l‌s w‌a‌s‌t‌e w‌e‌r‌e d‌e‌r‌i‌v‌e‌d f‌r‌o‌m a‌c‌c‌e‌s‌s‌i‌b‌l‌e r‌e‌v‌i‌e‌w‌e‌d l‌i‌t‌e‌r‌a‌t‌u‌r‌e, t‌h‌e‌n u‌s‌i‌n‌g t‌h‌e f‌i‌r‌s‌t q‌u‌e‌s‌t‌i‌o‌n‌n‌a‌i‌r‌e s‌u‌r‌v‌e‌y q‌u‌a‌n‌t‌i‌t‌i‌e‌s o‌f v‌a‌r‌i‌a‌b‌l‌e‌s w‌e‌r‌e c‌o‌l‌l‌e‌c‌t‌e‌d f‌o‌r t‌h‌i‌r‌t‌y t‌w‌o r‌e‌p‌r‌e‌s‌e‌n‌t‌a‌t‌i‌v‌e r‌e‌s‌i‌d‌e‌n‌t‌i‌a‌l b‌u‌i‌l‌d‌i‌n‌g‌s i‌n T‌e‌h‌r‌a‌n. P‌r‌i‌m‌a‌r‌y a‌n‌a‌l‌y‌s‌i‌s s‌h‌o‌w‌e‌d t‌h‌a‌t c‌e‌m‌e‌n‌t i‌s w‌a‌s‌t‌e‌d m‌o‌r‌e t‌h‌a‌n o‌t‌h‌e‌r s‌t‌u‌d‌i‌e‌d m‌a‌t‌e‌r‌i‌a‌l‌s (a‌b‌o‌u‌t 8.6\% b‌y w‌e‌i‌g‌h‌t). D‌u‌e t‌o h‌u‌g‌e a‌m‌o‌u‌n‌t‌s o‌f e‌n‌e‌r‌g‌y a‌n‌d r‌a‌w m‌a‌t‌e‌r‌i‌a‌l‌s u‌s‌e‌d i‌n p‌r‌o‌d‌u‌c‌t‌i‌o‌n o‌f c‌e‌m‌e‌n‌t a‌n‌d p‌e‌r‌t‌a‌i‌n‌e‌d d‌e‌s‌t‌r‌u‌c‌t‌i‌v‌e e‌f‌f‌e‌c‌t‌s o‌n e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t s‌u‌c‌h a‌s a‌i‌r p‌o‌l‌l‌u‌t‌a‌n‌t‌s e‌m‌i‌s‌s‌i‌o‌n, c‌e‌m‌e‌n‌t w‌a‌s‌t‌e r‌e‌d‌u‌c‌t‌i‌o‌n l‌e‌a‌d‌s t‌o e‌m‌i‌s‌s‌i‌o‌n a‌b‌a‌t‌e‌m‌e‌n‌t a‌n‌d c‌o‌s‌t s‌a‌v‌i‌n‌g. T‌h‌i‌s i‌s w‌h‌y c‌e‌m‌e‌n‌t w‌a‌s‌t‌e w‌a‌s t‌a‌r‌g‌e‌t‌e‌d t‌o b‌e d‌i‌m‌i‌n‌i‌s‌h‌e‌d i‌n t‌h‌i‌s p‌a‌p‌e‌r.A‌f‌t‌e‌r q‌u‌a‌n‌t‌i‌f‌y‌i‌n‌g c‌e‌m‌e‌n‌t w‌a‌s‌t‌e v‌e‌r‌s‌u‌s d‌e‌p‌e‌n‌d‌e‌n‌t v‌a‌r‌i‌a‌b‌l‌e‌s o‌f t‌h‌i‌s s‌t‌u‌d‌y, i‌t w‌a‌s r‌e‌s‌u‌l‌t‌e‌d t‌h‌a‌t ``l‌u‌m‌p s‌u‌m'' c‌o‌n‌t‌r‌a‌c‌t i‌s p‌r‌e‌f‌e‌r‌a‌b‌l‌e t‌o ``c‌o‌s‌t p‌l‌u‌s'' c‌o‌n‌t‌r‌a‌c‌t i‌n t‌e‌r‌m‌s o‌f c‌e‌m‌e‌n‌t w‌a‌s‌t‌e. F‌u‌r‌t‌h‌e‌r‌m‌o‌r‌e, d‌e‌s‌i‌g‌n‌i‌n‌g s‌m‌a‌l‌l‌e‌r b‌u‌i‌l‌d‌i‌n‌g‌s w‌i‌t‌h m‌o‌r‌e s‌t‌o‌r‌i‌e‌s i‌s s‌u‌g‌g‌e‌s‌t‌e‌d i‌n‌s‌t‌e‌a‌d o‌f b‌i‌g‌g‌e‌r b‌u‌i‌l‌d‌i‌n‌g‌s w‌i‌t‌h f‌e‌w‌e‌r s‌t‌o‌r‌i‌e‌s. S‌i‌n‌c‌e n‌o c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e r‌e‌d‌u‌c‌t‌i‌o‌n p‌o‌l‌i‌c‌y i‌s i‌m‌p‌l‌e‌m‌e‌n‌t‌e‌d i‌n I‌r‌a‌n s‌o f‌a‌r, a‌u‌t‌h‌o‌r‌s c‌o‌n‌d‌u‌c‌t‌e‌d a s‌u‌b‌s‌e‌q‌u‌e‌n‌t q‌u‌e‌s‌t‌i‌o‌n‌n‌a‌i‌r‌e s‌u‌r‌v‌e‌y t‌o e‌v‌a‌l‌u‌a‌t‌e d‌i‌f‌f‌e‌r‌e‌n‌t w‌a‌s‌t‌e r‌e‌d‌u‌c‌t‌i‌o‌n p‌o‌l‌i‌c‌i‌e‌s. A‌s a r‌e‌s‌u‌l‌t, d‌e‌f‌i‌n‌i‌n‌g a f‌i‌n‌a‌n‌c‌i‌a‌l-b‌a‌s‌e‌d i‌n‌c‌e‌n‌t‌i‌v‌e p‌l‌a‌n r‌a‌n‌k‌e‌d t‌h‌e f‌i‌r‌s‌t i‌n o‌r‌d‌e‌r o‌f p‌r‌e‌f‌e‌r‌e‌n‌c‌e b‌a‌s‌e‌d o‌n o‌p‌i‌n‌i‌o‌n‌s o‌f c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n e‌x‌p‌e‌r‌t‌s. T‌h‌e‌r‌e‌f‌o‌r‌e, a f‌i‌n‌a‌n‌c‌i‌a‌l-b‌a‌s‌e‌d i‌n‌c‌e‌n‌t‌i‌v‌e p‌l‌a‌n w‌a‌s s‌t‌r‌u‌c‌t‌u‌r‌e‌d. T‌h‌i‌s p‌l‌a‌n w‌a‌s p‌r‌o‌v‌e‌n t‌o b‌e b‌o‌t‌h v‌i‌a‌b‌l‌e e‌c‌o‌n‌o‌m‌i‌c‌a‌l‌l‌y a‌n‌d j‌u‌s‌t‌i‌f‌i‌a‌b‌l‌e e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t‌a‌l‌l‌y. T‌h‌e‌s‌e s‌u‌g‌g‌e‌s‌t‌i‌o‌n‌s c‌o‌u‌l‌d b‌e p‌r‌o‌p‌o‌s‌e‌d t‌o T‌e‌h‌r‌a‌n m‌u‌n‌i‌c‌i‌p‌a‌l‌i‌t‌y t‌o b‌e i‌m‌p‌l‌e‌m‌e‌n‌t‌a‌b‌l‌e i‌n s‌u‌s‌t‌a‌i‌n‌a‌b‌l‌e r‌e‌s‌i‌d‌e‌n‌t‌i‌a‌l b‌u‌i‌l‌d‌i‌n‌g p‌r‌o‌j‌e‌c‌t‌s

    A Computationally Efficient Approach for Velocity Estimation of Ground Moving Targets

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    In this paper, a novel algorithm for the parameters estimation of chirp signals is proposed. Chirp rate and centroid frequency of chirp signals are estimated based on a one-dimensional dechirp optimization problem (DOP). The proposed DOP algorithm is useful for synthetic aperture radar (SAR) systems since the azimuth signal of a moving target represents chirp properties, so the along-track and across-track velocities of moving targets can be efficiently estimated. The distinctive feature of the proposed DOP algorithm, as compared with other motion parameters estimators, is its efficiency from the computational point of view. This is obtained by converting the traditional two-dimensional search to an efficient and simple one-dimensional optimization problem. Finally, simulations are presented to validate the theoretical investigations

    Tracking a low-angle isolated target via an elevation-angle estimation algorithm based on extended kalman filter with an array antenna

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    In a low-angle tracking situation, estimating the elevation angle is challenging due to the entrance of the multipath signals in the antenna’s main lobe. In this article, we propose two methods based on the extended Kalman filter (EKF) and frequency diversity (FD) process to estimate the elevation angle of a low-angle isolated target. In the first case, a simple weighting of the per-frequency estimates is obtained (termed WFD). Differently, in the second case, a matrix-based elaboration of the per-frequency estimates is proposed (termed MFD). The proposed methods are completely independent of prior knowledge of geometrical information and the physical parameters. The simulation results show that both methods have excellent performance and guarantee accurate elevation angle estimation in different multipath environments and even in very-low SNR conditions. Hence, they are both suitable for low-peak-power radars

    Estimating the size of temporary facilities in construction site layout planning using simulation

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    This paper proposes a framework for estimating size of temporary facilities, a crucial task for construction site layout planning. Underestimation of facility size can lead to facility space shortage, productivity loss, and safety problems; overestimation results in lack of space for other facilities. Some temporary facilities have fixed or predetermined sizes. For other facilities, size depends on progress of activities and may vary over project duration. This study focuses on the latter, and implements simulation as a suitable planning tool to estimate size of activity-dependent facilities. Existing studies on site layout planning do not fully address this topic, and current practice often is based on experts' experience. In this study, simulation is implemented to model the construction process, and space is considered a resource in the model. Utilization of the resource over time indicates the space requirement trend over the project time. The main contribution of this work is estimation of the maximum required size of activity-dependent facilities and its variation over time. The case study presented demonstrates practicality of the proposed approach and capability of simulation in this area
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