A. Ghanbari; S. S. Zerangzadeh; F. Rezaee; S. J. Zakariaee
Abstract
In this study, the geologic formations of central part of Karaj alluvium are studied and a new division for layers is presented. The results of hundreds geotechnical in-situ and laboratory tests in Karaj alluvium were carried out and analyzed. Based on soil material properties, the study area is divided ...
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In this study, the geologic formations of central part of Karaj alluvium are studied and a new division for layers is presented. The results of hundreds geotechnical in-situ and laboratory tests in Karaj alluvium were carried out and analyzed. Based on soil material properties, the study area is divided to six individual layers. In each layer, the results of a large number of in situ and laboratory test to determine geotechnical properties of soil are classified and analyzed. Finally, average geotechnical parameters for different layers of soil in study area are presented. To determine the range of modulus of elasticity and relation between bearing capacity and SPT number in Karaj alluvium, results of laboratory and in-situ tests were assessed and compared with instrumentation data.
A. Ghanbari
Abstract
The results of over 100 geotechnical site investigations in different zones of Tehran alluvium in the south part of Tehran city were analyzed to determine the correlation of modulus between elasticity and SPT number of soil in southern Tehran alluvium. The alluvial deposits in southern Tehran are composed ...
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The results of over 100 geotechnical site investigations in different zones of Tehran alluvium in the south part of Tehran city were analyzed to determine the correlation of modulus between elasticity and SPT number of soil in southern Tehran alluvium. The alluvial deposits in southern Tehran are composed mostly of fine-grained materials or coarse-grained soils with silt and clay particles. Based on the soil material properties, the study area is divided into three sections. In each section, the results of a large number of in situ and laboratory tests are classified and analyzed to determine the elastic modulus of soil.
The study shows that, for the first part of the area the modulus of elasticity from plate load test correlates well with SPT number and for the second and third parts, the direct shear and triaxial tests have an acceptable correlation with SPT number. Formulas relating elastic modulus to standard penetration test number are given and compared to those reported in the literature. Also, from the analysis of data it was seen that the elastic modulus of soil is increased with increase of maximum soil particles. Finally average results for unconfined strengths of fine grained soil in alluvium of the south of Tehran are presented.
G. Barzegari; A. Uromeihy
Abstract
Development of liquefaction in saturated cohesionless deposits is one of the most dramatic causes of damage in civil structures during earthquakes. The potential damage caused by liquefaction includes: 1) loss of bearing capacity, 2) excessive settlement, 3) lateral spreading, 4) flow failure, and 5) ...
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Development of liquefaction in saturated cohesionless deposits is one of the most dramatic causes of damage in civil structures during earthquakes. The potential damage caused by liquefaction includes: 1) loss of bearing capacity, 2) excessive settlement, 3) lateral spreading, 4) flow failure, and 5) ground oscillation.
The liquefaction susceptibility of a specific deposit is affected by many factors for example, wave-induced liquefaction characteristics, soil type, geological history, confining pressure, permeability, relative density, water content, and properties of the soil grain size.
Chapar-Abad Dam is an inhomogeneous earth-fill dam with height and crest length of 44.5 and 427 meters, respectively. The reservoir capacity is 127 million cubic meters. The dam which is under construction is located about 75 km southeast of UromiehCity, in West-Azerbaijan province. The foundation materials include 60 meters of alluvium deposits overlying the bedrock layers of carbonate units. The abutments consist of carbonate and schistose layers of Precambrian age. In this paper the potential of liquefaction of the site is evaluated according to the SPT results form in-situ tests performed in boreholes driven into the depth of alluvial deposits. Furthermore, recently modified relations of correction factors such as stress reduction factor (rd), earthquake magnitude scaling factor for cyclic stress ratios (MSF), overburden correction factor for cyclic stress ratios (Ks), and the overburden normalization factor for penetration resistances (CN) are presented and used in liquefaction assessment of alluvial foundation at Chapar-Abad Dam. The results indicate the possibility of liquefaction and instability of granular soils during earthquake and any types of strong motions.
