The purpose of this paper is to review computational methods in structure-soil-structure interaction. As a result of globalization, buildings are located close to each other. This issue happens especially in big cities, making the study of structure-soil-structure interaction as an essential part of structural design process. The effect of soil medium, on which the building structure stands, especially on seismic behavior of building is well known. The effects of structures standing in a close distant to each other is the main issue in structure-soil-structure interactions. In this paper, analytical models of soil are reviewed. After a review on different analytical models of soil, the concepts and the computational efforts in the field of interaction between soil and adjacent buildings are discussed in order to provide the reader with the benefits and weaknesses of each concept. Different computer programs which suit structure-soil-structure interaction analysis and their main abilities are briefly reviewed as well. تفاصيل المقالة

Since the analysis of underground structures in seismic conditions was more based on non-linear terrestrial environment and linear structure, regarding nonlinear behavior of soil and tunnel against earthquake was of paramount significance in order to achieve real responses in practice. The use of polypropylene fibers in concrete materials can help improve the performance of concrete members. In this regard, after verifying the behavioral model of fiber-reinforced concrete seen in the structure of the tunnel and using an article by Conforti et al., the nonlinear seismic analysis of the ground and the structure of the water transmission tunnel of Amirkabir Dam to Tehran refinery no. 6 was performed by a time-history method and through ABAQUS software and concrete damage plasticity model for concrete lining and mohr-coloumb model for host soil of tunnel. Simulations were performed for the fibers with percentages of 0, 0.7, 1 and 1.5. Then, compressive and tensile stresses, compressive and tensile strains, and compressive and tensile failures were obtained while tunnel lining in the mentioned conditions. Since then, normal and shear stresses and normal and shear displacements of the longitudinal joints of the tunnel were examined. Finally, this paper studied the analytical relationships that existed in the ACI 544.7R-16 regulations and the moment-force diagram for the different percentages of fibers for the joint with the maximum normal stress under earthquake records were compared. تفاصيل المقالة

Concrete structures may be exposed to high heat. In such a way that high heat in the vicinity of concrete structures causes damage in concrete. The aim of this study is assessment of effect of electric high heat on the bending capacity, energy absorption, fracture type and crack distribution of circular fiber concrete slab under monotonic loading. The concrete aggregates with a fracture percentage of 45% are from the mines around Tehran and the fibers used in the concrete are of macrosynthetic type. The concrete mixing design was based on the target compressive strength of 45 MPa and the amount of fibers equal to 0.5% of concrete volume. The heating of the concrete samples was done by a 2400-liter device with a power of 90 KW and maximum temperature of 550 degrees Celsius. To perform slab tests, Dartec9600 device was used with monotonic loading at a rate 0.004 mm/s. based on the Experimental studies conducted on the fiber concrete slab, the application of high heat did not cause concrete peeling but it reduced the capacity of the slab by 89.3% and decreased the energy absorption of the slab compared to the control sample. Also, SEM photos have shown the aggressive destruction of macrosynthetic fibers and the creation of cracks under the effect of high heat in fiber concrete. تفاصيل المقالة