نشریه عمران و پروژه
پیاپی 1 (خرداد 1398)

Failure and buckling in shell structures, including silos, can be created for various reasons such as distortion, defects created during construction, defects created during operation, or environmental factors, etc. Silos can be subjected to a variety of lateral and axial loads, but since they are in fact affected by the combination of these loads, silos behave under the influence of composite loads. The silos in this research are hot-rolled and located on the ground. The variables of this research are type and scope of defect. Silos are also evaluated in semi-filled and semi-solid state. The model silos were analyzed in ANSYS software. The radial radial neural network RBF was used to predict the buckling capacity of the cylindrical shells. The results of this study indicate that artificial neural networks are a good tool for predicting buckling capacity of silos with defects.

One of the biggest environmental problems and problems in the world can be recycled and the reuse of worn plastics, which, due to their indissolubility, remains in the environment, and their disintegration may last more than a hundred years. One of the most widely used plastic molds, PETs, or polyethylene terephthalate, is the reuse of these wastes in concrete can be one of the ways to recycle this product. In the field of using polymeric waste, especially PET, in self-compacting concrete, research is in its early stages. Highly flowing self-compacting concrete can be a good solution for the construction of structures with complex and rebar shapes without the need for a vibrator. Therefore, in this paper, laboratory studies on self-compacting concrete containing different percentages of crushed petroleum fraction particles as part of the sand with two water-to-cement ratios were 0.45 and 0.41. Also, metalaole and microsilica additives were used as a substitute for cement to improve the efficiency of the compound, and then the flow of slump, funnel V, box L, compressive strength, tensile strength and elasticity modulus were used. As the water-cement ratio increases in the mixing scheme of self-compacting concrete, self-cleaning properties decrease, as well as decreases in compressive and tensile strengths, by partially compensating the pozzolan to concrete. The results show that the addition of crushed PET particles to the concrete composition reduces self-healing properties, but replacing the sand with the crushed particles of PET can make the composition of fresh concrete self sufficiently acceptable. By examining the results of the mechanical tests of hardened concrete, it can be concluded that increasing the amount of PET particles in concrete leads to a decrease in ... compressive strength, tensile strength and elastic modulus, although this loss of properties by replacing part of the cement with metalaole and microsilica individually and simultaneously It is partially offset. How many ?

The present study was conducted to investigate the reduction factors of construction waste in folding logistic projects in Sirjan city. The statistical population of this research includes contractors and engineers and all factors related to construction. The sample consists of 86 people who were selected by simple random sampling method. The instrument used in this research is a researcher-made questionnaire and a 9-factor questionnaire fuzzy ahp. Five hypotheses are the modernization of the construction industry. Proper design and consistent adaptation to changing needs. Proper storage and transportation methods and the use of recyclable materials, which proved these assumptions. An expert questionnaire has been reviewed to prioritize these hypotheses, and the criteria for each of their hypotheses have been identified. The results showed that storing and transportation of first and second rank and proper design and updating of the construction industry and the use of recycled materials are respectively from the highest to the lowest priority, and according to the criteria according to the type of order and fit with the climate conditions, the lack of coordination in the design and Implementing and using industrial methods and reuse of recyclable materials are more important than other components of their group. Once priorities are identified, management can make better decisions and plans to reduce construction waste, as well as information from well-known experts who use the system as
A decision support system.

What criteria can be used to describe the importance of BIM technology for the construction community is still a controversy among the experts in the science of project management. Whether BIM is merely a facilitator of work or an intrinsic need for a project is a debate that has engendered the field of project management in recent years. This research is a continuation of this discourse. In this research, a model based on the theory of fuzzy sets has been presented to evaluate the risk reduction of productivity in construction projects (coupled with BIM) under the influence of uncertainties. In this proposed model, six types of risk have been investigated. This approach enhances the flexibility of the proposed method in modeling real projects. Before proposing a method, ultimately, an algorithm for determining a slight increase in the efficiency of a project, A method for determining the impact of risks on time and manpower has been proposed.
The ultimate goal in this study is to transform qualitative concepts into quantitative quantities So that experts get a deeper understanding of the importance of BIM. Fuzzy logic along with artificial intelligence are the right tools to direct conceptual research to Palpable quantities. In a literal sense The numerical values obtained at the end of the work will ultimately provide an idea to follow the productivity path of the BIM-compliant projects. What risks are more effective in reducing manpower productivity, how to influence time in productivity, and to provide a method for transforming mental accumulations into numbers and one's awareness.