Journal of Engineering Geology

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 Knowing the engineering geological characteristics of carbonate formations is necessary for database. In this research, using petrological study and mechanical tests on 5 types of Ilam-Sarvak formations limestones in Khorramabad city, their engineering geological characteristics were determined and the relationship between physical and mechanical properties have been analyzed. IBM SPSS Statistics (version 19.0) software was used to determine the required relations. The relations have high correlations. Based on the studies on this of thin sections, rocks are characterszed as biomicrite. Limestones of Ilam-Sarvak formations have high hardening and low porosity. These rocks are in medium to high density, very resistant durability index, medium to high UCS and high point load strength category. The rocks are also impermeable. Based on the UCS, modulus ratio of the intact rock, the limestones are CM and CL. According to solubility test, the solution velocity constant was 1.39×10^-6 m/s.

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The Minab (Esteghlal) dam site is located in east of Minab city in Hormozgan province. The Minab active fault cross the reservoir of dam and have an important role in leakage from the reservoir. The joint study of area in ten stations around the reservoir of dam display the four main joint sets. For assessment of leakage of reservoir, the permeability of rock masses outcrops in the reservoir is estimated by hydraulic conductivity HC experimental model. For this, the RQD, GSI and other characteristics of rock mass around the reservoir were measured in field studies. The results show that the permeability of embankments changes from 9.14×10-6 up to 2.02×10-5 m/s. Also the water lost for three different condition of minimum, mean and maximum level of water table is about 0.14, 0.20 and 0.29 m3/s. The results indicate that the discontinuities with trend of east-west and northeast-southwest and also shear fault zone of Minab have main effects in leakage of reservoir.

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For prediction of exact effect of soil temperature, soil water retention, unsaturated hydraulic conductivity and water flow of soils on seep development, information about soil hydraulic, physical properties soil temperature is necessary. In this study, using geophysical and thermal methods the hydraulic properties and thermal conductivity of unsaturated porous media was estimated. Infiltrated water temperature was 50° C and the temperature data used in inverse solution technique was recorded by 2 thermal sensors during 3255 sec. One of thermal sensor was installed at a depth of 50 cm and the soil hydraulic and thermal parameters were estimated using 48 collected data of the injection water temperature variations. In this research 121 geoelectrical sounding with the Wener, Schlumberger and polar-polar arrays configuration were used. Evaluation and interpretation of the sounding curves show that the water table is located at depth of 75 meters. Top alluvium layer (unsaturated zone) is composed of three layers. In this study, to investigate the distribution and diffusion of pollutants in the unsaturated zone, the brine concentration of 20 g/L was used. Wener and polar-polar arrays were used to detect and image the contaminants plume. The polar-polar configuration shows less spreading of contaminated plume in both vertically and horizontally direction than the Wener array.  Particularly by the Wener configuration the plume depth is more underestimated than the real value. Based on water injection visibility in the vicinity of the trenches and observing the water seepage at the trench face, the real velocity of the water at direction of 35 degrees relative to the horizon was measured equal to 0.159 m/h. Horizontal and vertical contaminant plume expansion coefficient was determined equal to 1.4. Evaluation of thermal and hydraulic properties of unsaturated porous media was done by HYDRUS-2D software. In this study five hydraulic parameters &thetar, &thetas, &alpha, n and Ks and five soil heat transfer parameters including the &lambdaL, &lambdaT, Cn, Co and Cw were included in the parameter estimation process. After implementation of the parameter estimation (adjusted for ​​observed and predicted temperature values) Coefficient of Determination  R² was equal to 0.97 and the objective function value was equal to 11.5. Computational error in the mass balance was about 67 percent. 

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This paper presents a case study of the instability mechanism, to verify and reinforcement method adopted construct collapsed zone of Sabzkuh water conveyance tunnel in southwest Iran. The instability problems were encountered during tunnel excavation due to the failure, changes in stress field lead to deformation causing dilation and increasing the permeability of sand and gravel layers, local fault gouge zones, landslide and in turn significant reduction in shear strength and collapse in tunnel. IPE Arch Support Technique (IAST) was, used for T1 part of Sabzkuh tunnel zone in order to reinforce the ground around tunnel and to cross the zone falling. In this study, Finite Element Method was employed for the quantitative reinforcement effect with deformation modulus of ground, IPE length and size. As a result, the settlement increases as length increases and decreases with the increase of the deformation modulus of ground and IPE size.  

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The Kandovan village is one of the tourist attractions in East Azarbaijan province of Iran, whose rural houses were excavated within the cone-shaped pyroclastic rocks (in terms of local called keran) several hundred years ago. The present paper discusses the role of engineering geological properties of Kandovan pyroclastic rocks. Kandovan pyroclastic rocks have low resistance against weathering and erosion because their components are plagioclase minerals and pumice fragments with low resistance, welding, sorting and high sphericity and rounding. Although weathering and erosion along existing joints and fractures is the most important causative agent of cone-shaped forms but there is the possibility of further damage of rocks due to continuing these processes. High porosity of rocks has caused that their high capacity for water absorption. High water absorption percent increased sensitivity of rocks against expansion and contraction by freezing-thawing and wetting-drying cycles and low hardness and low their internal strength caused the rocks weathered and disintegrated due to environmental factors. Furthermore, the weak texture of the pyroclastic rocks have caused easy erosion of those by surface waters and wind.

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The Dynamic Probing is an important test in site investigation and geotechnical studies. It is used for determination of situation and specification of soil layers when the depth of exploration is moderate. In our country, in the last few years test has been widely used to replace the standard penetration. In this paper, the experiences to use different various types of dynamic probing rigs and the errors that can occur in these experiments are discussed. Then the accuracy of this test is studied to evaluate the specification of fine-grained soils. The most important innovation of this research is the proposition of the new correlations between cone dynamic resistance and undrained shear strength and so compaction percentage in fine-grained soils. The paper encourages the wider application and further development of this test for site investigation in fine-grained soils.

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Determination of Faults activity rate is among the most important parameters of evaluating faulting hazards. In this paper, active faults on region of Shahid Rajai dam of Sari with radius 100 km based on fractal dimension of faulting and earthquake as well as evaluation of slip rate were classified and those Activity rate were assessed. In order to determine of fractal dimension of faulting and earthquake, Box-counting method was used. For estimate of slip rate beginning the seismicity parameters (a&b) of study area was estimation. Then these parameters were normalized for each fault. Based on the existing relationships and having a&b for each fault, the seismic moment of fault was calculated. Finally according to extant relations for evaluation of seismic moment rate, slip rate of each fault was determined and the faults of study area were classified accordingly. By grading based on fractal dimensions, the faults of North- Alborz, Damghan and Garmsar have been the most active faults in the study area during the last 100 years and according to evaluations of active rate of faulting and earthquake based on fractal dimensions, generally set in category BD and their activity approved. The faults with very low slip rate and with long return period of earthquake, are possible causes of occurrence large earthquakes (856 AD) Gomes and inducement fault namely Damghan Fault is an example of these faults. The faults of Astaneh, Rameh and Cheshmeh-ali have been low slip rate and thereupon be able to develop high seismic moment rate. According to earthquake events in privacy of New faults introduced (Khorram-abad, Majid,…), the high activity rate of these faults seem logical

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In this research attempts were made to estimate the in-situ stresses acting on a hydrocarbon reservoir based on routine activities of acid injection in oil reservoir. It was found that the relation between the re-opening pressure of fracture and principal in-situ stresses can be estimated using rock mechanics equations for the circular underground cavities. An appropriate relation between the maximum and minimum horizontal principal in-situ stresses and reservoir parameters such as permeability, reservoir pressure, Young’s modulus, acid viscosity, injection flow rate and etc., was developed by using the well-known Darcy equations for fluid flow in porous media. Accordingly, knowing the flow rate of acid injection during well operations and some other reservoir parameters, in-situ stresses may be estimated. The method was then successfully applied to a large carbonate reservoir as a case study in south-west of Iran. Maximum and minimum effective horizontal stresses were calculated by employing the presented method. 

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Measuring of uniaxial compressive strength (UCS) of intact rocks is required in many engineering projects. In deep well drilling for petroleum production or exploration drilling in deep tunnels, because of depth of wells, obtaining suitable core samples for UCS test is too expensive and sometimes impossible. Therefore, indirect methods for determine UCS (for example using rock particles) are common. One of these methods is known as indentation test. In this test an indenter that is hard penetrates into rock particle which is surrounded by resin used. In this paper, 11 microcrystalline limestone block samples from carbonate Zagros formation outcrops were prepared and UCS test in laboratory was performed. Then cores are crushed and 720 rock particle samples with 2, 3 and 4 millimeter size was prepared. Indentation test with indenter 0.6, 0.8 and 1 millimeter diameter was done and critical transitional force (CTF) for each particles was determined. Empirical equation between UCS and CTF for different samples and has been provided. Based on the obtained results it is suggestedto utilize indenter with a R²&ge0.78. Using multiple regression general equation between UCS, CFT, particle size (D) indenter diameter (I), R²=0.85 is proposed. 135 indentation tests were performed on 3 microcrystalline limestone samples with the aim of verification of obtained empirical equations. Comparing measured UCS in laboratory and estimated UCS values showed 88% similarity

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One of the best approaches to reduce transportation problem is to use the underground tunnels. Therefore, Niayesh highway tunnel was performed by the New Austrian Tunnelling Method (NATM) in the northern part of Tehran and it includes north and south tunnels. The excavation of tunnels and other underground structures cause considerable changes in local stress conditions around structures that lead to surface settlement. In this research, surface settlement has been studied for five sections (CS-1 to CS-5) by empirical methods, numerical analysis and actual settlements. For the empirical and numerical methods, O’Reilly and New (1982) method and also finite element method (PLAXIS_2D software) have been used, respectively. On the basis of the obtained results, the numerical method in all sections (except section 3) is in agreement with the actual settlements. While, empirical methods have estimated the settlements more than actual values in those sections.  Also, the achieved results from the aforementioned methods show that the maximum settlement due to tunnel excavation is more than allowable settlement and it is in risk condition

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The pseudo-static analysis is one of the conventional methods in embankment dams design and International Commission on Large Dams (ICOLD) suggests using this method before ultimate dynamic analyses. In this research, the static, pseudo-static and dynamic analysis of Masjed Soleyman embankment dam was performed. Using dynamic and pseudo-static analyses results, the safety factor of critical sliding surface was calculated. Permanent displacements of critical sliding surface were evaluated by New mark method and the calculated safety factor was compared. Based on the comparison results in different water levels of the reservoir and by introducing a new equation, the variable horizontal acceleration coefficients in height of the dam body were calculated. Finally, the obtained horizontal acceleration coefficients were compared with the other criteria introduced in different embankment dam's design codes. Totally, the results indicate that the proposed method leads to a larger horizontal acceleration coefficient in higher parts of the dam body.

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 In this research, prediction of concrete strength containing different aggregates using Non-destructive (Ultrasonic) testing through Artificial Neural Networks was carried out. For this purpose, aggregates with different properties were selected from the quarries, and then their destructive and nondestructive properties were obtained in laboratory. The significance of this research, using different aggregates with physical, mechanical and chemical properties also used two different test methods, such as Non-destructive static and dynamic testing, which are respectively uniaxial compressive strength and compressive wave velocity. Thus, this model includes various types of samples and the prediction model includes static and dynamic tests. The results showed that the use of artificial neural networks not only increases the accuracy, but also it reduces costs and time.

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Unpredicted and excessive tool wear is a major challenge in some tunnel projects. Due to more need for maintenance, abrasivity problems increese time and cost of excavation activity. A new laboratory test machine has been built in Engineering Geological Laboratory of Ferdowsi University of Mashhad, to obtain a proper view about relation between performance parameters of a TBM and the soil abrasion. In this paper the results of abrasion tests carried out on silica samples, as an abundant hard mineral, by the machin, are presented. Hence 36 tests have been performed on coarse silica sand samples, with various amount of deadweight and rotation speed at different times. The results prove direct relation between time, surcharge and rotation speed versus tool wear. For example a linear relation between tool wear and surcharge or rotation speed was observed. Besides a logarithmic relation was achieved for time effect

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Mountains are usually formation origin of their neighbor land surface features such as hillsides and plains. some problems and errors may occur in application of RS technique for generation of geology maps and in separation of these units from other similar units. The main objective of this study is to integrate RS and geomorphology approaches for identification of different geomorphology units and finally separation of debris lime stones from massive lime stones in Bahadoran region, Yazd province. For this purpose, a Landsat ETM⁺ image was acquired together with band ratios, principal component analysis and factor analysis approaches to generate lime stone distribution map. Results of this study show that (integration of RS and geomorphology sciences) can better generate the lime stone distribution map compared with the first one

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Stability and safety of the dam is one of the most important challenges during construction and operation. The aim of this study is to make accurate water table and piezometric heads through embankment and its foundation of the Shahghasem dam which is located near Yasouj city. Applying geostatistical, Simple Kriging, Ordinary Kriging and Weighted Moving Average, interpolation was done using Gaussian, exponential and spherical models. For comprising the results, we use the statistical index including MAE, MBE, RMSE and GSD. Results indicate that Simple Kriging with Gaussian model is the best one, while Ordinary Kriging with Gaussian model and Ordinary Kriging with spherical model are in the next order. The Weighted Moving Average method with different exponents shows a significant error comparing to other methods. As a result, the depicted maps display a cavity through foundation near right abutment of the dam. Finally, existence of probable cavity in foundation may cause piping and internal erosion

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The use of heavy concrete as a protective shield against high-energy gamma rays is very common. It is also an effective, versatile and economical material. The heavy concrete production can use lead slag as raw materials. The use of lead slag in the production of concrete blocks saves natural resources and reduces the environmental problems caused by the accumulation of industrial waste. However, concrete production, due to the presence of heavy metals with high atomic number can be used as an effective shield against gamma radiation. This study examines the use of lead slag produced in the battery recycling process as concrete aggregates. For this purpose, strength and gamma-ray attenuation coefficient for concrete samples prepared by replacing 40 to 60 percent lead slag instead of natural aggregate. The effect of 1 to 5 percent lead powder in setting time of concrete was measured. The results showed that by increasing the amount of lead slag, density, mechanical strength and gamma-ray attenuation coefficient for concrete samples increased significantly, but lead powder delays setting time of cement paste. In general, appropriate lead slag concrete construction with minimal thickness, reduce the cost of protection and provides the highest level of attenuation

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 The average of shear wave velocity of the upper 30 m has so far been one of the reliable parameters in seismic site classification in different building codes, despite the numerous weaknesses in the exact explanation of site dynamic characteristics. In this study, an empirical relationship is obtained between the average of the shear wave velocity of the upper 30 m and the average of the shear wave velocity of shallower depths, based on 79 shear wave velocity profiles, in Mashhad. This is followed by the recommendation of proper depths for the dynamic analysis of the site effect based on the information of shear wave velocity profiles and resonance period distribution in the investigated area. The depth of the S-wave velocity profile investigation, required for the analysis of deposit effects has been estimated more than 30 m. whith exception of the southern and western parts of Mashhad (adjacent hillsides). Such depth is estimated as about 80 m for central, eastern, and north-eastern areas, where the resonance period is more than 0.7 s. Therefore, investigation depth of 30 m is only adequate for site classification based on the building codes, and for theoretical analysis deeper studies is needed, in Mashhad

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Among dynamic parameters, the maximum shear modulus and damping ratio of the materials has the great importance in the dynamic analyses. In this paper, the high frequency GAP-SENSORs (20 kHz) is used to measure shear wave velocity of the sandy and gravelly Dacite materials in the cyclic triaxial equipment. The test procedure is as follows: firstly, a weak impact on the top cap triaxial specimen is induced. The induced low horizontal and vertical displacements time histories (strain in the range 10-6) are recorded using data logger with rate of 100,000 samples per secent for each channel. Then by traveling time and distance between two GAP-SENSORs, wave velocity is measured. Finally, by calculating the poison ratio via horizontal and vertical strains, the maximum shear modulus of the material is calculated. The results indicate that the value of wave velocity is increased by increasing confining pressure, and their values are dependent on particle size. Also, using the reduced vibration amplitude technique at different levels of specimen, damping ratio value is calculated by temping method. By comparing the results of shear modulus and damping ratio using local measurement of axial strain (with GAP-SENSORs in the cyclic triaxial) at small strain level with the results of the proposed method, cofirmed the high precision of the innovative used method.

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Non-destructive methods such as ultrasonic wave velocity are extensively used for estimating physical and mechanical properties of rock due to the simplicity, economical, fast and harmless nature. Rock constructions have been made worldwide from past to present. Determination of strength of rock constructions such as archeological evidence is not possible using conventional rock strength tests. Developing a cheap, simple, non-destructive, efficient and accurate method to estimate the strength of such constructions can be useful. Rock blocks and constructions have various shapes and sizes. Rock blocks having various shapes and sizes have been prepared from marble, travertine, granite, and limestone and ultrasonic wave velocity at various directions of the blocks dimensions and the uniaxial compressive strength of cylindrical core obtained from the blocks have been measured. The results show that shapes and sizes have no effect on the ultrasonic wave velocity. At the end relationships between uniaxial compressive strength and ultrasonic wave velocity have been determined. The uniaxial compressive strength of blocks and rock constructions can be estimated by the obtained relationships using non-destructive, simple and indeed low cost method of ultrasonic wave velocity.

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Marly rocks of Abtalkh formation were classified by Q, RMR, RSR and RQD rock mass classification systems using 222 meters logs from exploratory boreholes in Doosti dam site. The results show that the RMR is the most suitable method for classification of studied rock masses and has highest correlation coefficient with RQD. The validity of different Q-RMR equations was studied using error ratio (ER). Cameron et al. (1981) and Morno (1982) equations have lowest ER and highest validity for studied marlstones. Bieniawski (1989) and Cameron (1981) relationships are lower and higher limits of equations for marly rocks respectively.