Results of laboratory tests on specimens produced from subsoil studies were evaluated to characterize GEOTECHNICAL PROPERTIES of Tabriz Marl. It was concluded that, Tabriz Marl may be considered as a high liquid limit silt or clay (MH & CH). Range of changes of index, physical and mechanical PROPERTIES of the Tabriz Marl are comparatively vast. Correlation between these PROPERTIES has been introduced in this paper. A representative specimen was tested for swell potential after compaction and also for thermal and lime treatment effects. Swell percent and pressure as high as 13.6 % and 1020 kPa were measured and need for treatment was proved. It was shown that with thermal treatment substantial modification only starts as the temperature rises beyond 300° C. At 500° C the plasticity index and also the swell percent decrease to less than 5.0 % and 1.0 %, respectively. With lime treatment, plasticity index decreases as the lime content is increased until the lime fixation point is achieved at about 3 % lime content, beyond which, modification effects are not considerable. Addition of just 1.0 % lime to the soil decreased the swell potential to 5.0 %. Further results, merits and shortcomings of both treatment methods are introduced during the text.

Despite of different studies performed on Tehran geological condition, the GEOTECHNICAL and dynamic PROPERTIES of Tehran alluviums are not investigated in detail. In this study the authors have tried to get more detail information about south Tehran alluviums by compiling the data from 700 boreholes and 66 seismic profile investigations. The defined 15 two dimentional EW seismic GEOTECHNICAL profiles by the distance of 1km present the GEOTECHNICAL and dynamic PROPERTIES of the south Tehran alluviums. Based on these sections the depth of the seismic bedrock increases from north to the south. In addition it is demosntrated that S wave velocity variation in the study area follows the difference of soil type observed in the presented sections. It seems that the local changing of the water table and the seismic bedrock depth could be related to North-Ray fault and Punakhzad fault effects.

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.

In this research, effects of pine tree sawdust on GEOTECHNICAL PROPERTIES of two types of kaolinite clayey soil was evaluated. So that, sawdust in 3, 6 and 9 percent (by weight) in dry condition randomly mixed with two kaolinite clayey soil with different plasticity index. Compaction, uniaxial, permeability (falling head) and consolidation tests were performed on specimen. Results showed while 3% sawdust mixed to samples, 24% minimum void ratio (emin) decreased in kaolinite clay with high plasticity index. Also, in this condition, increasing of bearing capacity and strength, ductility and decreasing in water absorbing have been happened.

Nowadays new materials for improving bearing capacity of soils are widely used. Kind of new materials used in this regard are geosynthetics. Geofoam panel type of geosyntethic materials is useful and alternative for backfill in retaining wall or pavement layers. Main idea in this research is study geofoam particles effects on improvement bearing capacity of sand. Geofoam particles effects on sand in 0. 05, 0. 1 and 0. 15% percent were considered and sand was considered in granular and angular conditions. In order to evaluating geofoam particles influence in GEOTECHNICAL PROPERTIES of sandy soils some laboratory tests such as compaction, direct shear (in vertical stresses 1, 2 and 3 kG/cm2) and permeability tests were performed. Results of this study showed that with increasing 0. 15% percent geofoam in sandy soils maximum dry density went up, permeability decreased and shear strength of specimens increased. Although, geofoam particles is more effective in angular sandy soil than granular sand.

The present study is to elucidate and efficacy of Ultra-fine slag and Calcium Chloride in improving the Engineering characteristics of expansive soil. An experimental program has evaluated the effects of Ultra-fine slag 3%, 6%, 9% and CaCl2 0.25%, 0.5%,  1.0%, Free swell index, swelling potential, swell pressure, plasticity, compaction, strength, hydraulic conductivity, Cation Exchange Capacity and microstructural XRD, SEM tests of expansive soil and also a statistical tool was used to predict the experimental values of unconfined compressive strength of the soil. Both admixtures were added independently and blended to the expansive soil. Mixing of Ultra-fine slag, CaCl2 and expansive soil results have shown that plasticity index, hydraulic conductivity, swelling PROPERTIES of blends decreased and dry unit weight and unconfined compressive strength is increased in combination of soil +6% of Ultra-fine slag + 1% CaCl2. The unconfined compressive strength (UCS) of the samples is again found to decrease slightly beyond 6% Ultra-fine slag and 1% CaCl2. It was found that the optimum quantity of material for a favorable combination of soil +6% of Ultra-fine slag + 1% CaCl2 was taken for further study in view of its economy due to lower CaCl2 content.

The environment is faced with various pollution. Pollution with oil and oil derivatives such as gasoline and diesel is one of the most dangerous environmental aspects. Organic chemical materials are the basis of many industries such as fuel refining, petrochemical complexes, pesticides, and detergents. Inappropriate use of organic chemical materials can cause irreparable damage to the environment which has caused increasing concern in different countries. In addition to the harmful environmental effects such as groundwater and seawater pollution, it causes changes in the GEOTECHNICAL PROPERTIES of the soil, which manifests itself in cohesive soils with changes in the texture and overall structure of the soil. In this research, the laboratory investigation of the GEOTECHNICAL PROPERTIES of silty soil contaminated with different percentages of gasoline (5, 10, 15%) by performing the Atterberg limit tests (the liquid limit and the plastic limit), uniaxial compression strength, direct shear and compaction tests were carried out. The obtained results show that 27% decrease in the liquid limit and 48% decrease in the plastic limit with an increase in the amount of soil pollution with gasoline. Also decreasing trend is observed in the shear strength parameters of silty soil polluted with different percentages of gasoline. The results of both direct shear and uniaxial compression strength tests demonstrate decreasing in the shear strength of polluted soil with the same trend.

In this study, the effect of nanokaolinite particles on GEOTECHNICAL PROPERTIES of clayey soils is investigated. The mechanical method of Planetary Ball Mill was used for production of nanoparticles. For this, initial kaolinite powders was milled in Planetary Ball Mill for 10 hours with speed of 500 Rpm of machine. Output powder was in nanometer scale that images produced from FESEM verified this. Then, nanoparticles were mixed with clayey soil (CL) in different weight ratio of dry soil and change percentage of GEOTECHNICAL PROPERTIES of treated soils was investigated by compaction, direct shear and cassagrande tests and optimum percentage of added nanokaolinite was determined. Results showed that LL and PL of soil increased while percentage of added nanoparticles increased but since increasing of PL is larger than LL, thus PI is decreased that it is favour for GEOTECHNICAL engineering for construction. Also with attention to results of compaction tests, density of clayey soil was increased with adding of nanoparticles to an optimum quantity and after it decreased. It is determined from direct shear tests that cohesion of clayey soils increased with adding of nanoparticles to optimum quantity and after it is changeless approximately. Results of XRD and XRF tests showed that chemical integition of nanoparticles produced from planetary ball mill is similar to initial powder and not change.

Holocene in Southwest Khuzestan is represented by a fluvio-tidal succession termed the Bahmanshir Series which consists of two clayey layers separated by silty sand to silt beds. This paper describes the GEOTECHNICAL PROPERTIES of the clayey layers that have wide exposure in the lowlands of the Persian Gulf coast. Studied layers are generally clay sized and consist of a lesser percentage of clay minerals. Most of the clayey layers have intermediate plasticity, and low potential for expansion. The variation of physical and engineering PROPERTIES of the layers from base to top and along the Bahmanshir River is investigated in this research. The engineering PROPERTIES of the beds seem to be affected by tidal and river flow currents and totally by their formation sedimentary environments. Links of the GEOTECHNICAL data with geological features as formation sources in the upstream of the basin, the cementation due to the capillary feature in the floodplain sub-environment and the flocculated texture of clays in the brackish water, have been discussed in this paper. Overall, it is observed that the GEOTECHNICAL data could be correlated with the geological features of the Bahmanshir Series.

In the last five decades, the rise of the plastic industry led to increase in the waste of plastic in the environment, therefore the scientists were thinking to reduce plastic waste by recycling the plastic. On the other hand, there is a problem of collapse of gypseous collapsible soil upon wetting. In this paper, one of the methods to recycling plastic is adopted to improve the gypseous soil by mixing with 1% plastic fiber to increase the shear strength and improve collapsibility of soil at the state of saturation or soil wetting. The soil used is classified as SW-SM, the gypsum content is 39% and the relative density is equal to 73%.Fiber plastic is made from plastic waste in the environment of investigation. Several tests were conducted on the soil such as collapse test, direct shear test, also model loading test on the soil before and after mixing with fiber plastic. The worst case of gypsum soil is at saturation by rain or groundwater rise which was simulated during the loading test. It was concluded that the value of soil cohesion gradually increases from 2 MPa at the state of the natural soil to 11 MPa after mixing with 1% of plastic fibers. From the three model loading tests, the load carrying capacity of a model footing on submerged gypseous soil increased from 2.66 MPa for untreated soil to 4.8 MPa when the soil is mixed with 1% plastic fiber and extended to a depth of 0.5 B. The earing capacity also increased to 6.8 MPa when the soil is mixed with 1% plastic fiber and extended to a depth of B.