Tunnel boring machines (TBMs) are one of the mechanized drilling tools that have grown because they have good performance. Selection type of TBM depends on the various parameters that some of these parameters are in conflict with each other. Therefore, TBM selection process is very complex. There are different methods for decision making and selection that can mention methods such as multi criteria decision making, Fuzzy logic and Expert System methods. AHP and TOPSIS methods of the subsets of multi criteria decision making method are appropriate tools for selection under the complicated circumstances. On the other hand due to exist uncertainty in the collection of information, using fuzzy approach is useful. In this paper a combination approach Fuzzy AHP and Fuzzy TOPSIS is used to select optimized TBM for water transfer tunnel of Dashte Zahab. The results show double shield TBM is the most appropriate TBM for this tunnel.
APPLICATION OF SMART MATERIALS IN CIVIL ENGINEERING STRUCTURES
The conventional building materials like stone, brick, timber, steel, concrete, etc., are dumb materials as they lack the ability to sense their surrounding and adapt themselves. Biological objects in the nature have this sensual characteristic which is called biomimetics. They collect the information from the surroundings, decipher them and act accordingly. This is what is called smartness and intelligence. Materials possessing these features are called smart materials or intelligence materials. Structures constructed with such materials or techniques and coupled with IT are called smart or intelligence structures. Shape memory alloy (SMA) is one of the popular metals that have the sensual properties. This is frequently used as braces in framed structures, as damping elements to suppress the vibration of structures, as self-rehabilitating structures, only to name a few of its usages. Of late, SMA is used in conjunction with FRP as reinforcement in concrete structures to control deflection. Also, SMA-FRP bars have more potential to improve the ductility and energy dissipation capability of concrete structures compared to conventional FRP bars. SMA fibers have also been used to prestress concrete to prevent its cracking at design load. The paper describes the characteristics of smart materials, the use of SMA in construction and research, and their beneficial aspects by reviewing the available information.
SELECTION OF SHAFT SINKING METHOD BY FUZZY VIKOR APPROACH
Shaft sinking is one of the main parts in underground mine planning. Shaft has various applications in underground mines such as minerals exiting flow, gases entrance, stope developments for exploitation, etc. Considering that this section requires an abundance of expenses, management always following the election is the way that both terms have the technical considerations, economic constraints are also considered. Therefore, selecting shaft sinking method is one of the biggest concerns of underground mines management. There are some methods for this purpose including Delphi, ELECTRE, TOPSIS and VIKOR. This paper intends to use VIKOR method under fuzzy environment in order to choose a ventilation shaft sinking method for Parvade Mine located in Coal Zone of Tabas. The results indicate that raise boring machine (RBM) method is the most preferable method.
SUSTAINABLE UTILIZATION OF BOTTOM ASH AND FOUNDRY SAND IN CEMENTATIONS COMPOSITION: REVIEW
The objective is to provide practical information, regarding the effective use of foundry sand and bottom ash in mortar/concrete. The present study was conceived following the general purpose of testing new sustainable building processes and modern production systems, aimed not only at saving natural raw materials and reducing energy consumption, but also to recycle industrial by-products. It particularly focuses on the use of bottom ash and foundry sand in mortar and concrete. Thus, this paper reviews the developments and present state of the effective and sustainable utilization of foundry sand and bottom in building materials: mortar and concrete. Recent researches in bottom ash and foundry sand and its use in the cement-based materials has been presented which will be beneficial to the concrete industry.
REVIEWING PERFORMANCE OF PILED RAFT AND PILE GROUP FOUNDATIONS UNDER THE EARTHQUAKE LOADS
The primary idea of using deep foundations was brought up, in order to control overall and differential settlement of foundation under heavy structural loads. However, gradually by increasing height of structures, using deep foundations as piled raft and pile group were considered for controlling inversion and deal with shear loads resulting from the earthquake, more than was previously considered. But the important matter about deep foundations is to focus on shearing and bending forces in connection place of cap to piles, as well as their growth in depth, which it must be reviewed accurately for planning goals. There has been used from ABAQUS finite element software, to investigate interaction of soil, foundation, and structure. The studied soil is clay type with Mohr-coulomb behavioral model, which it have been used from un-drained shear resistance (SU), in order to consider un-drained conditions under dynamic load. There have been used infinite elements around the soil model, in order to consider transient boundary conditions and semi-infinite mass. There have been modeled structural sections with dual system performance in three storey type, including 10, 20, and 30 storey with square and rectangle cross sections. Dynamic loading has been applied in bedrock level as time history acceleration. The study aims to review transaction effect of soil, foundation, and structure for transferring shearing resulted from earthquake to superstructure, pile group loading share from horizontal loading and shearing and bending forces in piles.