JOURNAL OF GEOTECHNICAL GEOLOGY (APPLIED GEOLOGY)
Year:2013 | Volume:9 | Issue:2|Papers Count:9

Shurijeh formation is one of the gas reservoir formation located in the Koppeh-Dagh basin NE Iran that component very hard formation in terms of drilling. Cognition physical and mechanical characteristics of the formation, would be author a more precise planning for operations drilling and could be to some extent be avoided spending of high cost of drilling these formation. In this study, tests the triaxial compressive strength, porosity test (with helium gas and water saturation) and Cerchar Abrasive Index (CAI) on samples of core taken from this formation and also preparation thin sections of the samples and determine the mineralogy and texture, was studied physical and mechanical properties this formation that finally it was found these samples contain plenty quartz mineral and has texture of sub-arkoz. Also was investigated, compressive strength of these samples in three-axis test at three levels stress 5, 10 and 15 Mpa and shear strength parameters C and  F for the samples was obtained respectively 15.3 Mpa and 53.79 o. In addition, further tests shows that these samples In terms of abrasion considering high quartz mineral content, are located range of very abrasive rocks. The results of this study can be used to design suitable method of Shurijeh formation drilling.

This study was done with aim of relative Hazard zonation of slope instability and landslides occurrence in the Kesmat basin with an area of 27 km2, 50 km southeast of Khoramabad city. In order to check the stability of slopes in this basin, in the first step landslide prone areas were identified using the aerial photography and field surveys and then distribution map of landslide is provided. By merging the effective factors included slope, aspect, altitude, geology, earthquake, rainfall, landuse and distance from the fault and drainages on landslide with the landslide distribution map, impact of each of these factors assessed in ArcGIS software and using the AHP model. Then these factors were prioritized using AHP model. According the results of use the AHP in landslide risk zonation, 0.05, 12.64, 28.56, 31.35 and 27.4 percent of the area are located in very low, low, medium, high and very high risk classes respectively.

Determination of geomechanical parameters of rock joints is very important. One of the main geomechanical parameters is the shear strength of rock joints. For achievement to this purpose, many experiments have been carried out. In this study, by performing the direct shear test on andesite rock joints, the real impact of joint roughness on shear strength were interpreted and analyzed. In this study, the effect of joint roughness with concept of joint roughness coefficient (JRC) on shear strength of strong rock joint in both low and high normal stress has been investigated. The results showed that, the effect of joint asperity on shear strength of rock joints is more specific at low normal stress level. Then, the shear strength values that measured from laboratory direct shear tests on natural rock joints were compared with the shear strength values that estimated by using Mohr-Coulomb, Power curve and Barton criteria. From analyzing the results and comparison them with these criteria by using statistical analysis were found that power criterion in comparison with other criteria has better agreement with the results of direct shear test on andesite samples.

Upper Gotvand earth type dam with 180 meters height and a clay core is constructed. This dam is going to be the highest earth dam in Iran and in the first phase target would be production of 1000 MW electricity. In this project four intake tunnels with 12.6 feet diameters will be excavated on the left bank of the dam. As permanent structures, support design of these tunnels is vital task. The aim of this research is stability analysis of the intake tunnels to design temporary support. For this purpose, empirical methods (RMR rock mass classification) and numerical method (FLAC software) were utilized. Finally, temporary support system suggested for the tunnels with using empirical and numerical method.

The NE oriented Dasht-e-Arjan graben is located in 65 Km West of Shiraz and is resulted from the active Kare-e-Bas fault segmentations. This extensional graben bounded by two boundary east-Arjan and west-Arjan fault system perpendicular to the Shahneshin anticline and Salamati anticline. In these study linear structures, using SPOT satellite images with a spatial resolution 2.5 m and directional filtering in the four azimuths and semi-automatic technique the structural lineaments of the study area have been extracted. We have partitioned the study area to 1, 4, 9, 16, 25 and 36 equal-area quadrangles have been selected, using the obtained data from extracted lineaments, the rose diagrams using output data were obtained main strike of lineaments, in 6 columns from west to east, are well confirm with field measurements of faults trend N56o±4oE of the study area. The analysis of the data from slickenlines in order to reconstruction the orientations effective stress using of graphic method (fault-slip inversion technique) was performed. The position and trend of the principal stresses, respectively s1 is N23oE, 72ºNNE, and s3 is S58oE, 26oSE, and s2, isS34oW, 10oSWwas obtained.

In this study, it has tried to calculate properties related to reservoir of Upper Sarvak formation in one of the south oil field for wells A and B using of wire line logs and Geolog software. Helping conventional cross plots (RHO-NPHI, RHOB- DT, MID plot and M-N plot) Lithology of Upper Sarvak formation in understudied region is calcite, dolomite and low shale. In according to calculated Petrophysical Properties, for better evaluation, Upper Sarvak formation divided to 5 zones. Zone 2 having of special petrophysical properties, divided to 8 subzones. Finally, Zone 2 has been distinguished as the best zone of reservoir because of petrophysical suitable properties.

In the present study, the effects of waste calcium carbonate on properties of rubber were investigated. The rubber samples were prepared with weight percentage 15Wt% of waste calcium carbonate (four different samples), pressed in 4-MPa and sintered at 1500C for 60 minutes. The properties such as hardness, elongation at rupture, tensile strength and 300% modulus were measured. The chemical analysis of calcium carbonate was investigated through X-Ray Fluorescence method (XRF) and sizing distribution of calcium carbonate were carried out through Laser Particle Size Analyzer device (LPSA). The results indicated that by increasing the waste calcium carbonate weight percentage up to 15Wt%, the physical properties of the rubbers improved. Also, more increasing the waste calcium carbonate led to decrease in favorable properties and standard.