نشریه زمین شناسی محیط زیست
پیاپی 18 (بهار 1391)

In this paper, using SGR (Site Groundwater Rating) method, 11 km of Amirkabir tunnel has been studied and categorized into quantitative and qualitative classes from groundwater hazard point of view. Considered parameters in this method are: joint frequency, joint aperture, karstification, crashed zone, schistosity, and head of water above tunnel, soil permeability and annual raining. Using SGR method, tunnel site can be categorized into six different classes from no risk to critical. According to this classification more than 60% of Amirkabir tunnel has been located in no risk class and results are compatible with the results of analytical method.Furthermore, approximately 5% of tunnel has been found in critical class that mostly coincides on crashed zones and following analytical method results, inflow rate is 0.46 L/sec/m in this portion of tunnel.

Blasting is a key element in mining operation that constitutes near 30% of total mining cost. If this process does not carry out correctly, it will increase up to 50% with secondary blasting. A proper basis blasting operation not only can reduce side effect on the environment, but also can get rid of some undesirable consequences such as back break, fly rock and secondary blasting. Concerning the above notations a predetermination of a method to estimate the size of the fragmented rock and scattered fragmentation is so important and the results are so beneficial. In this study after performing a series of blasting at Gol-e-Gohar iron mine using artificial neural network some models for predicting fragmentation have been achieved. In order to select the best blasting pattern concerning fragmentation, Tagochi method was utilized. In these series of experiments, fragmentation results by using these two methods was 57.5 and 60 cm respectively, which are close to fragmentation at the mine. Consequently, some environmental problems were solved by using this pattern of blasting at the Gol-e-Gohar iron mine.

The Sachun Formation is one of the lithostratigraphy units in south-west of Iran. This Formation in Zarqan section with thickness of 259.6 meters consists of various layers of colored shale/ marl, evaporate and carbonate sediments. It sandewiched between Tarbur and Jahrom Formations. Its lower contact with the underlying Tarbur Formation is unconformable, but its upper contact with overlying Jahrom Formation is conformable.Recognized facies of this formation sediments in Zarqan Section (folded Zagros zone) comprise carbonate, evaporate and terigenou which divided in two facies belt of tidal flat and lagoon. Totally 11 facies and sub-facies have been recognized; 5 tidal falt, 4 lagoon and 2 terrigenous facies. Abundance of shallow facies against lack of deep facies indicates that the Sachun Formation have deposited in a ramp platform. Due to Sequence stratigraphy study of this formation in Zarqan section, one sedimentary sequence has been determined with a type one sequence boundry in its lower contact with Tarbur Formation.

Various types of numerical analyses such as the finite element method, the boundary element method and the distinct element method, are used in rock mechanics and in engineering practices for designing rock structures such as tunnels, underground caverns, slopes, dam foundations and so on. In this paper, the results of back analysis of Koohin tunnel which is located in the first section of Qazvin – Rasht railway have been presented.The main purpose of this paper is to perform the back analysis of the mentioned tunnel with the use of numerical models. For modeling the tunnel, two different sections are analyzed with Flac 2-D software, which are 30+150 and 30+900. To perform back analysis the suitable interval of geomechanical parameters according to the tests which performed on the core drillings has been determined. With the use of Direct Method in back analysis, the errors of models have been corrected in several steps and finally the geomechanical parameters of control in 30+150 station (Elastic Modules = 0.3 GPa, Cohesion = 0.21 MPa & Internal Angle of Friction = 34°) and in 30+900 station (Elastic Modules = 0.3 GPa, Cohesion = 0.21 MPa & Internal Angle of Friction = 35°) have been achieved. The geomechanical parameters which achieved from back analysis are completely in the chosen interval and compliance with the results of tests which performed on core drillings. On this basis and according to the match of the geomechanical parameters which obtained from back analysis with the parameters which used in designing of the tunnel, the tunnel design and the structure method were confirmed.

The aim of this paper is to offer a useful design to specify and choose suitable options for Tehran subway tunnel supports, line 3, phase 4 as a good model for later stages use. This pattern is formed on the basis of technical, financial, administrating, social and political and mechanical and effective factors on the site of doing the project by noticing a variety of criteria. Furthermore (on the other hand) subway tunnel supports include lattice girder,cement armed with armature using modular form work (frame work) system, fore poling, corrugated steel sheet and segmental lining in the model. And the final goal is selecting the most suitable option aimed all the probable options for choosing subway tunnel supports system and noticing effective and important criteria on which basis and by using multi-criteria decision making and new research methods during the operation, proper options are prioritize and ultimately the best ones are chosen. In TOPSIS method, alternative (E) is selected as the best alternative for support system.

The study area is situated at the western part of Lut desert and southern Tabas block. The existing red beds including Upper Jurassic-Lower Cretaceous marl, mudstone, siltstone, sandstone and conglomerates are in Kerman continental red formation and parts of Bidu and Gerdu formations. The host rock is a sub-mature litharenite or calcic subarenite. The intergrowth of the coarse chalcocite and fine covellite crystals as dark nodules filled the cavities and open spaces of the rocks. The mineral paragenesis is rutile, chalcocite, covellite and malachite. Mineralization occurred in the lower sandstone due to dissolution and leaching the copper at the surface layers and shift downward to the reduction zone beneath the water table. The copper amount is 1.5% and silver is 11 ppm. According to the current study, Shalapo is a stratabound sediment-hosted copper deposit.

The study area is located 59km southwest of Karaj City, in northern slopes of Mt. Jaroo. From structuralsedimentary classification point of view, the area is a small part of Orumiyeh-Dokhtar volcanic belt and from metallogenic viewpoint; it is western part of copper-gold zone of Saveh-Kashan-Naein. The basement rocks of the area are mostly lithic tuffs, andesite, dacite and diorite. Dacite to andesites are the main host rock of mineralization. According to the field studies and drilling observation, the mineralization is vein and open-spacefilling types and it is following local faults trends. Mineralization having east-west trend has less than 1200m length and 200m width. Its thickness (thickness of veins) reaches up to 1 to 2m. The mineralogical studies show that malachite and azurite are observed in surficial parts of the area while chalcopyrite, chalcocite, bornite and covellite are found at depth. The geochemical analysis of about 40 samples (outcrop and drilling) shows that anomaly for Cu, Ag, Pb, Zn and Au. Respectively, the anomaly for Cu and Ag are too high while average grades are for Cu about 5% and for Ag about 225 ppm. It is conclude that the Jaroo area can be considered as a small copper and silver deposit.

Sarein city from cities of Ardabil province is in Northwest of Iran that it has 9 hot springs. Water of springs used in spa and discharge in Kenzagh River that native inhabitants used for agriculture and livestock. Therefore,investigation the origin and type of spring water and the concentration of heavy metal and toxic elements in springs are essential. For investigation the type and source of water and waste water, sampled and some chemical and physical characteristic of the cation and anions main and heavy metal were measured. The results show that the amount of H2S and CO2 gases in the hot springs Sarein is high (8.16, 44 mg/l). According to Piper diagram,water of the hot springs is chloride and bicarbonate sodic type. The anion triangle diagram shows that the hot springs in the area Sarein peripheral and shallow waters is rich in carbonates. According to the Ficklin chart all springs are almost neutral. Maximum amount of detergent determined in 1 station that is 5.23 mg/l and Maximum amount of BOD is 1590 mg/l in 2 stations.