Sharif Digital Repository

One problem that has always been a challenge for geotechnical engineers is construction on problematic and soft soils. Traditional methods of lime and cement stabilisation can be used to treat soils with these properties. The main drawback of lime addition to the clayey soils is a significant loss in ductility of lime-treated soils. Using ductile materials such as geogrids in lime-treated soils is one of the most effective ways to increase the soil ductility. Therefore, the effect of geogrids and lime on unconfined compressive strength (UCS), failure strain (ɛf), secant modulus (Es), deformability indexes (ID), resilient modulus (Mr), bulk modulus (K), and shear modulus (G) of the treated... 

Construction over problematic soils is a common problem in many parts of the world, and one of the effective procedures to tackle this problem is soil stabilization. Accordingly, the current study provides the finding of a laboratory investigation into the effect of three kinds of nanomaterials, including nano-silica (NS), nano-clay (NC) and nano-calcium carbonate (NCC) on the properties of a loessial collapsible soil. To accomplish this issue, reconstituted samples of the stabilized loessial soil were prepared for unconfined compression and consolidation tests. The results illustrated that an insignificant amount of nanomaterials (less than 1% of the total dry weight of the soil when is... 

Construction over problematic soils is a common problem in many parts of the world, and one of the effective procedures to tackle this problem is soil stabilization. Accordingly, the current study provides the finding of a laboratory investigation into the effect of three kinds of nanomaterials, including nano-silica (NS), nano-clay (NC) and nano-calcium carbonate (NCC) on the properties of a loessial collapsible soil. To accomplish this issue, reconstituted samples of the stabilized loessial soil were prepared for unconfined compression and consolidation tests. The results illustrated that an insignificant amount of nanomaterials (less than 1% of the total dry weight of the soil when is... 

One problem that has always been a challenge for geotechnical engineers is construction on problematic and soft soils. Traditional methods of lime and cement stabilisation can be used to treat soils with these properties. The main drawback of lime addition to the clayey soils is a significant loss in ductility of lime-treated soils. Using ductile materials such as geogrids in lime-treated soils is one of the most effective ways to increase the soil ductility. Therefore, the effect of geogrids and lime on unconfined compressive strength (UCS), failure strain (ɛf), secant modulus (Es), deformability indexes (ID), resilient modulus (Mr), bulk modulus (K), and shear modulus (G) of the treated... 

This paper presents a new approach for unit commitment (UC); where a large scale wind power exists and the wind speed has a fuzzy characteristic; by using particle swarm optimization method (PSO). In this approach, the system reserve requirements, the requirement of having a load balance, and the wind power availability constraints are realized. A proper modeling of these constraints is an important issue in power system scheduling. Since these constraints are "fuzzy" in nature, any crisp treatment of them in this problem may lead to over conservative solutions. In this paper, a fuzzy optimization-based method is developed to solve power system UC problem with a fuzzy objective function and... 

Liquefaction phenomenon is usually accompanied by large amounts of settlement owing to disruption of soil structure. In addition to that, large settlement also occurs by a significant increase in soil permeability during seismic excitation. To properly simulate the post-liquefaction settlement, it is important to take the compressibility properties of the liquefied sand as well as the permeability increase into account. Using initial permeability coefficient in the course of simulation of liquefaction leads to underestimation of settlement. In addition to that, using unrealistic values for permeability may cause erroneous predictions of other aspects of soil behavior. Therefore, an accurate...