نشریه زمین شناسی محیط زیست
پیاپی 54 (بهار 1400)

Estimation of resistance parameters of rock mass is one of the most important engineering problems of rock.The study of geomechanical parameters and, finally, the classification of rock masses in the feasibility phase and the initial design of a project, which has very little comprehensive information on the geotechnical properties of rock masses, the amount of stress and the available hydrological characteristics, The main purpose of using a classification system is to classify the parameters and, using their results, provide the nature of the rock mass and its engineering behavior in different conditions. Since rock mass specifications are in the design of drilling, design of retainers, tilt design and other requirements. On this basis, it was considered necessary to obtain the resistance parameters of Khersan 3 Dam site so that, by analyzing these data, the stability of the tunnel, the geomechanical classification of rock mass using the RMR, QI, GSI method can be calculated and the relationship between rock mass resistivity parameters Compare the modulus of elasticity and deformation from different relationships and compare each other.

In this paper, based on the results of experimental and analytical methods, crushed zone and gurpy rocks masses were identified as the squeezing sections. Then crushed zone and gurpy sections creep parameters at the Bruger model were obtained in the laboratory. Then crushed zone and gurpy sections modelling using the software Flac2D with burgers model for 30 days (long-term) were performed. Our numerical modelling results show the large displacements due to very low quality of the rock mass and high overburden in this sections of the tunnel. The results of the numerical modelling in the short-term, that TBM shield would be stuck in this section of tunnel. Also modeling this section in the long-term showed that stability and not seen failure of the segmental support system. But effect squeezing in two sections is not critical. Among the important phenomena that makes problem for tunneling, support and tunnel usage is squeezing which is a type of problems that takes place in weak rocks. Squeezing of the rock is time dependent large convergence, which occurs around the tunnel, and is essentially associated with creep caused by exceeding limiting shear strength. Squeezing is one of the important phenomena in the tunneling industry so drilling in the squeezing cases can be causing serious problems. Predicting the amount of displacement, radial strain, shear strain and plastic zone increment as functions of the squeezing degree resonator factors is one of the basic needs in drilling and tunnel maintenance. Squeezing is behavior that related with weak rock mass deformation and strength properties. This phenomenon is associated with large deformations and time dependent convergence during tunnel excavation. It takes place when a particular combination of induced stresses and material properties pushes some zones around the tunnel beyond the limiting shear stress at which creep starts. Deformation may terminate during construction or continue over a long period of time. West Kermanshah tunnel conveyance (WKTC), with about 8550 meters long and 6.884 m in diameter in the west of Iran is located in Kermanshah province. Mainly parts of the tunnel pass through weak rock make is including types of argillaceous, sandstone and shale, with high 570 meters overburden and will be probably under squeezing condition. Duets in this project the effect of experimental methods, analytical and semi-analytical are evaluated. Then critical section of the squeezing potential presented and finally numerical modelling of this phenomenon is done.

The overall goal of this study is to investigate the impact of indigenous knowledge in ecotourism industry and generate revenue in Poloor region of Mazandaran province. This research is a survey study and information are collected based on  questionnaire in the format of Likert scale.. The studied population consists of 210 residents of Poloor region and sample size is achieved  111 randomly based on Cochran formula. But in field study , only 70 questionnaires have been completed and the others didn't tend to respond. Research reliability has been calculated by Cronbach's alpha and the value of this coefficient has been 0/803 . Variance analysis tests, Duncan compare means tests , Pearson correlation coefficient and simple regression have been used for data analysis. These analysis have been done by spss software. The results showed that, there's a significant relationship between indigenous knowledge, ecotourism industry and economical prosperity. It means that, with proper management based on indigenous knowledge, it is possible to  preserve natural resources areas especially pastures of the above region in addition of tourists attraction, job creation, revenue, cultural preservation of indigenous traditions.

Irregular emissions of metals from various industrial, agricultural and human sources have led toenvironmental pollution of heavy metals. Heavy metals are highly toxic to humans and animals. Amongthem, microalgae and cyanobacteria with the potential to grow in extreme conditions, including placescontaminated with heavy metals, have effective defense strategies to combat the toxic effects of heavymetal ions. In this way, they can accumulate high concentrations of heavy metals in their cellular organs.Potential efficiency in metal adsorption, accumulation and resistance in microalgae has led to theirrecognition as efficient microorganisms in the biosynthesis of metal nanoparticles and metal oxides. Inthis review article, the aim is to investigate different strategies for the removal of heavy metals as well asthe mechanisms of nanoparticle synthesis by microalgae. Obviously, studying the widespread use ofmicroalgae in the bioremediation industry can play an important role in conserving our environmentalresources in the future.

Considering the development of industry and technology, the accumulation of inviromental contaminants,especially heavy metals in the soil led to increasing concern about food security.The aim of  this study was to investigate the concentration of heavy metals in the surface soils of agricultural lands south of Bardaskan located in Khorasan Razavi. The soil samples were taken from depth of 10 to 30 cm soil by filed assessment.The dominant soil texture is gravelsandy and PH 7.3 and subalkaline. Mean total concentration of Cd,Cu,Mn and Mo were0.66,251,2176,6.67(ppm).The highest values of Igeo,EF and CF indicators were found for Cu(0.6),Mo(6.26) ,Mo(4.44).Pollution index calculated using the average of total CF was 2.36,indicating the medium contamination class in the area. High concentration of heavy metals Cu,Mo,Mn and Cd in the south of Bardaskan can be a threat to agricultural land in this area. geological structures such as faults, and human activities such as mining, agriculture, and industry can provided the necessary grounds  for soil  contamination with heavy metals and increase the concentration of heavy metals in the agricultural soil of the region. Monitoring the pollutants concentration in the agricultural soils as well as in agriculutral products is essential to conserve natural resources and ensure the food security.