Amin Keshavarz, Mehdi Nemati,
Volume 10, Issue 3 (Vol. 10, No. 3 Autumn2016 2017)
Abstract
In this paper, the bearing capacity of strip footings on fiber reinforced granular soil has been studied. The stress characteristics or slip line method has been used for the analysis. In the selected failure criterion, the orientation of the fibers are isotropic and fibers are not ruptured. Seismic effects have been considered in the equilibrium equations as the horizontal and vertical pseudo-static coefficients. The equilibrium equations have been solved using the finite difference method. The provided computer code can solve the stress characteristics network and calculate the bearing capacity. The bearing capacity has been presented as the bearing capacity factors due to the unit weight of the soil and surcharge. Several graphs have been prepared for the practical purposes. Also, a closed form solution has been presented for the bearing capacity factor due to the surcharge. By the parametric studies, the effects of the geometry and soil properties have been investigated. Results show that the bearing capacity increases with an increase on the average concentration and aspect ratio of the fibers, the fiber/matrix friction angle and the soil friction angle. Furthermore, the extent of the failure zone is increased with increasing the pseudo-static coefficients and decreasing the surcharge.
Mr. Masoud Esmaeilzadeh, Mr. Ebrahim Keshavarz, Mr. Mohammad Golkhandandan,
Volume 18, Issue 4 (Winter 2024)
Abstract
Estimating tunnel construction costs is one of the critical steps in project management. Several factors influence the total cost of a tunnel project, and the complexity and uncertainty in identifying these factors often lead to inaccurate cost estimates. Various analytical methods have been developed to estimate tunnel construction costs, but all have drawbacks. Utilizing real data from other projects can mitigate these shortcomings. In this research, we first discuss the growth of the tunneling industry and its impact on the development of economic infrastructure. We then review the historical research on tunnel cost estimation and the methodologies that have been developed in this area. The lack of a pricing schedule for tunnel construction in Iran, unlike in developed countries, results in inaccurate cost estimates for tunnel projects. This study examines both definite and probabilistic methods for estimating the cost of mechanized tunneling, based on the price schedule of "Dam Field 1403." We compare the cost of tunneling in Iran with other countries. The results indicate a 30% difference in the ratio of labor costs to the total project cost and a 92% difference in the cost per meter for mechanized tunnels in Iran compared to other countries. This discrepancy discourages private contractors from engaging in tunnel projects in Iran. Therefore, we propose the development of a comprehensive pricing schedule for tunneling to enhance the accuracy of cost estimation for tunnel projects in Iran.
