نشریه زمین شناسی مهندسی ایران
سال چهاردهم شماره 2 (تابستان 1400)

Contamination of water sources by pesticides is considered as one of the environmental problems which are on growth due to agricultural development and the variation of herbal pesticides. The present study aims at making a Biotite absorber to omit the organic pollutant of water. In the current study, Biotite, which is found naturally in Boroujerd, west of Iran, is used to absorb pesticides including Permethrin, Diazinon, and Malathion. The effect of concentration, pH, and contact time on pesticide absorption was studied. The findings revealed that the aforesaid absorber has had the appropriate return to absorb the mentioned pesticides. The highest percentage of permethrin absorption by Biotite took place in the concentration of 4 ppm, pH= 7, and contact time of 20 minutes, while the highest percentage of Malathion by Biotite occurred in the concentration of 4 ppm, pH= 7 and contact time of 40 min. The findings indicated that the process of diazinon absorption follows isotherms like Langmuir and Freundlich. However, the process of permethrin and Malathion absorption follows Langmuir isotherm and Freundlich isotherm respectively. Generally, the findings from the present study can be used to plan various ways to control contamination in the industrial scale, decreasing destructive environmental effects in the waters contaminated by pesticides.

Dimension stone reserves contains intact rock and discontinuity network. The intersection between discontinuities forms rock blocks with various geometry. Determination of rock blocks geometry is required in order to economical evaluation of stone reserves. Beside, extraction of stone blocks are preform by cutting planes, and the optimization of cutting pattern leads to increasing quarrying efficiency and decreasing production of waste in quarries. This procedure result less environmental damages and more economical beneficiations. The operation will reduce environmental impacts and increase economic interests. In this research, first, important features of discontinuities such as persistence, spacing, orientation, etc. have been extracted in the Kipul Quarry stone mine. then, using 3DEC simulation of the block model and using block modeling, different joint azimuth rotation was investigated in four classes. analyzing the results obtained from the modeling showed that in order to obtain maximum value, the current extraction direction must be 70 degrees west, which resulted in an average in situ block of 287.58cubic meters and the amount of coups sold in four classes 65826.27 cubic meters, which according to the current rate will generate about 115 billion and 98 million USD for this mine.

Artificial stone is a mixture of natural aggregate and additives such as industrial gums (resin), cement and other polymer materials. The purpose of this study is to compare the physical and mechanical properties of artificial stones made in different conditions, resins and aggregates. To achieve these goals, synthetic rock samples were made with polyester and vinyl ester resins and granite, lime, silica granules and lime-silica composites, with the existence and lack of vacuum and pressure during the fabrication of artificial stones. To determine the physical and mechanical properties (Brazilian Test, Point Load Test, Uniaxial Compression Test), artificial stones have been tested. Based on experiments, artificial stones made with vacuum and pressure systems have more favorable physical properties and undesirable engineering characteristics than coarse specimens made in completely manual conditions without vacuum and pressure systems. The specimens made with vinyl ester resin have more axial compressive strength than the other specimens and their fracture type is elastic - fracture but the specimens made of polyester resin without paying attention to aggregate type, show the elastic - plastic and creep behevior. Increasing of the resin percentage in artificial stones made of limestone, increases tensile strength but does not have a positive effect on granite. The results show that all the resistive properties of artificial stones are controllable. Also the mixing plan and ratio of mixing percentages are the most important principles in the strength and resistance of the artificial stone and are flexible for any use and taste.

Nowadays, modern and environmentally friendly methods have been used to stabilize soils and to improve soil engineering properties. One of these methods is formation of calcium carbonate precipitation in soil pores for increasing strength, cohesion, hardness of soil and decreasing soil permeability. Since most studies have been performed on the formation of calcium carbonate precipitation by using urea hydrolysis by bacteria. In this study, calcite precipitation was made by direct use of urease enzyme. In this method there is no limitation like using of bacteria and also there is no harmful effects on planting. This study investigated the effect of adding urease enzyme to cement and zeolite-stabilized sandy soils as well as the effect of fine aggregates. The results of the uniaxial strength tests showed that with 10% replacement of zeolite instead of cement while 10% fine grains were used, more resistance was observed to the samples without zeolite and with less fine grains. On the other hand, by adding urease enzyme with 4% cement, 10% fine grains and urease enzyme in the comparison of samples without enzyme increased the compressive strength at 14 and 28 days, 5.12 and 4.107, respectively.

Today, with the cities expansion and population growth, the need for high-rise buildings and deep excavations for their implementation is increasingly felt. Under constant loading conditions, soil undergoes deformations over time which is called time-dependent deformations. This is of particular importance in terms of safety in the long run. In this study, based on the physical modelling technique, the long term behaviour of stabilized deep excavation in silty sand, using the nailing method, has been investigated. The test results indicated that with increasing the depth of excavation the lateral displacements, the surface settlements behind the excavation wall and also the time-dependent deflections increase as well. In addition, if the excavation operation is brought to a temporary halt or is led to the abandonment, it results in a significant increase in the time-dependent deflections. Finally, the recorded data revealed that the rate of the experienced deformations over time decreases which is due to the gradual mobilization of forces in the nails.

The purpose of this research is to study the engineering geological characteristics of the caliche in quaternary sediment of Sanandaj city. For this purpose, 6 boreholes were drilled in wet and dry seasons of the year, SPT test was performed during drilling to evaluate the strength of the layers. Then, to study the geotechnical parameters of the caliche Laboratory tests such as petrographic (thin section, XRD, XRF), determination of physical properties (dry and saturation density, moisture content, water absorption and porosity), characterization Mechanical and resistive (uniaxial compressive strength, point load and durability index evaluation) were performed. After determining the engineering geological characteristics of the caliche, the relationship between the petrological characteristics and the physical-mechanical properties and durability has been investigated. Finally, with regard to study investigation have done the mentioned parameters, the application of these materials and the methods of improvement if they are encountered at the project site are discussed

In the past decades, Iran faced severe rain deficiency and/or uneven distribution of location and time of rainfall. This has initiated dilemma for over consumption of underground water. In this research, economic and engineering analysis for comparative advantage of construction of a human-made pond-like reservoir based on the local price of freshwater and local climate in 31 provinces across the country was conducted. Among various criteria, the price of freshwater and evaporation were the most critical ones. However, other parameters such as temperature, reservoir geometry, annual precipitation and seepage were discussed. Accordingly, construction of a reservoir at Khorasan-South (Khorasan-Jonoobi) province was the most economical compared to other provinces. Markazi and Yazd provinces were the next most economical ones across the country. It was noted that temperature is an essential parameter affecting local evaporation and the impact of temperature is more prominent than the relative moisture. For example, Hormozgan and Bushehr provinces sustain high evaporation while relative moisture is high (and therefore low evaporation is expected). Further, analysis revealed that morphological and engineering characteristics of reservoir such as the reservoir volume, depth of water and the reservoir surface exposed to the air and to the sun light may somewhat be controlled in order to reduce evaporation.