The Sharbyan river is located in the Sharbyan village, Sarab, East Azarbaijan province. This river alluvials are supplied from rock units belonging to Oligo-miocene and Miocene, including conglomerate, sandy lime, limestone, marl and shale. These deposits are used as raw materials of producing hot asphalt in two asphalt plants that have been built in the vicinity of this river, and the produced asphalt is used mainly in the neighbor provinces that have rather cold climate. Combined analysis of the sediments indicate high level of silica, around 60 percent, for which the prepared asphalt is prone to stripping phenomenon in the cold seasons. During this process, the moisture penetration in aggregates and asphalt mixtures, causes weakening bitumen-asphalt materials bounding and finally asphalt demolition. The role of sediments and its impact on the quality of asphalt has not been studied in this area, therefore, the solutions for dealing with this phenomenon is also examined and presented. This study is based on the conventional sedimentology methods, different standards of ASTM, AASHTO and Ministry of Roads and Urban Development guidelines. In this study, the combined effects of hydrated lime (lime filler) and natural filter materials with different proportions was used to deal with the stripping phenomenon, and the parameters of strength, softness, indirect tensile strength, asphalt quality and durability criteria, have been appraised. The results show that these parameters are improved using additives in various proportions and the produced asphalt quality and durability is better. The results illustrate, when the lime is used in its maximum ratio of 3%, stripping score is 1 and is disappeared by other parameters improvement
This paper presents landslide assessment and landslide hazard zonation of the Polroud Dam area. Polroud Dam is one of the largest dams that are in construction, 29 km south of Roudsar in Gilan Province. Considering to geomorphology and geological conditions of the area, the site is susceptible to landslide hazard. Field survey shows many evidences of the instabilities especially in the slopes overlooking to the dam and the reservoir. The historical record also demonstrates high potential of the region to slope instabilities. A large landslide that occurred in 1996 discern that the frequency of the hazard in the region. Therefore, Identification of the landslide potential hazard is vital before impounding the reservoir. In this study, we investigated landslide hazard in the site and we have prepared landslide hazard zonation map using the main parameters. These parameters include; slope percent, slope aspect, lithology, fault, roads, drainage catchment, elevation, vegetation and precipitation amount. Analytic Hierarchical Process (AHP) has been used to prepare and to cross the maps. The results show that about 26 percent of the slopes are situated in highly hazard zones. It was determined also that lithology and slope aspects play main role in occurring of the landslides in the study area.
Soil nailing is a prevalent method for temporary or permanent stabilization of excavations which, if it is used for permanent purposes, the seismic study of these structures is important. There are a few physical models, with limited information available, for the study of behavior of soil nailed walls under earthquake loading. Numerical methods may be used for the study of effects of various parameters on the performance of soil nailed walls, and this technique has been used in the current paper. In this research, the effects of various parameters such as the spacing, configuration, and lengths of nails, and the height of wall on seismic displacement of soil nailed walls under the various earthquake excitations were studied. To investigate the effects of the configuration and the lengths of nails on the performance of these structures, two configurations of uniform and variable lengths of nails have been used. To study the effects of the spacing between nails and the height of the wall the spacings of 2 and 1.5 meters and the heights of 14, 20, and 26 meters have been considered. The seismic analysis has been carried out using the finite element software Plaxis 2D. To analyze the lengths' of nails, it was assumed that the safety factors of stability of different models are constant, and the limit equilibrium software GeoSlope was used. After specification of the lengths of nails based on constant safety factor of stability, the deformations of the models under several earthquakes records were analyzed, and recommendations were made on minimizing the deformations of soil nailed walls under seismic loading.
Komrud village of located on the slope is particularly susceptible to landslides. The slope stability analysis is of special importance because of landslides or slope failures can cause major damages life and financial. In studies to determine the factors and parameters affecting the slope is unstable. According to studies, one of the most important factor affecting landslides in this area is the force exerted by the acceleration of the earthquake. With this approach, the maximum possible acceleration of earthquakes in a 50-year period is estimated at the site. On the other hand, based on studies of the geological is determined profile of the slope geometry, physical and resistance parameters to the landslide susceptible. Then using the modeling software in FLAC 2D 5.00 elasto-plastic structural models, with failure criteria Mohr – Coulomb, stress-strain behavior of the soil has been examined to pseudo-dynamic method. A base position at the top of the slope is considered and displacement it horizontally to reach the maximum possible acceleration is calculated and recorded. The results of this study indicate that Horizontal displacement followed the landslide, can be occur below the maximum acceleration estimates.
Soil classification is one of the major parts of geotechnical studies. So assessment of existing methods for soil classification in different areas is important. For soil classification is used in situ and laboratory test results. Sampling and identification tests are laboratory methods for soil classification. CPTu test is in situ method for soil identification and classification, due to accuracy and speed, this test is used widely in geotechnical study today. Many researchers are proposed some charts for soil classifications based on the parameters measured in CPTu test. In this paper for evaluation the performance of these methods, 58 CPTu test results have been used. These tests are related to four areas in southern Iran. The soils are classified by CPTu methods and then they are compared with 372 laboratory soil classification. Research results show the chart proposed by Robertson (1990) which based on Qt, Ft and Bq variables has the best adaptation with the laboratory soil classification in these studied areas. Then according to data obtained from research, proposed a modified charts based on Rf, qt-u0/σ΄ v , that show 90% adaptation with laboratory soil classification.
The Schmidt hammer provides a quick and inexpensive measure of surface hardness that is widely used for estimating the mechanical properties of rock material such as uniaxial compressive strength and Young’s modulus. On the other hand, Schmidt rebound hardness can be used for a variety of specific applications. In the mining industries, it is used to determine the quality of rock, which is common practice when constructing rock structures such as those found in long wall mining, room and pillar mining, open-pit mining, gate roadways, tunnels, dams, etc. However, a number of issues such as specimen dimensions, water content, hammer type, surface roughness, weathering, testing, data reduction and analysis procedures continue to influence the consistency and reliability of the Schmidt hammer test results. This paper presents: a) a critical review of these basic issues and b) avaluate the effect of temperature, moisture and uniaxial compressive stress on Schmidt hammer hardness. It was found that water content has a significant effect on the Schmidt rebound hardness (SRH) of rocks. So that increase of water content substantially reduced the SRH of samples. Temperature also had a considerable influence on the SRH. However, relationship between SRH decreases with increasing temperature for tested samples were linear. Also tests results showed that uniaxial loading of samples increases the SRH values.
This research focuses on the identification and description of various features of pseudokarst in different parts of Alvand granitic batholith, Hamedan, west of Iran. In the literature, karst features have been presented as specific types of terrain or landscapes with particular characteristics suites of well-known surface and subsurface dissolutional forms. Whereas, pseudokarst refers to non-dissolutional surface or subsurface features and landforms created in different areas such as slopes, coastal lines crushed stone areas, lava tubes and permafrost regions. In this research, a comprehensive field investigation program has been carried out. During the field investigations, the most important features of pseudokarst in Alvand granitic batholith have been recognized and classified. Results show a wide range of pseudokarst features in the Alvand granitic rock masses. These landforms are created by erosion, weathering processes and some holes caused by rock block movements along the rock slopes. Some of the most important forms and features of the pseudokarst in the studied area are consist of tafoni, genama, pseudokarren, talus caves, caves associated with the residual blocks and erosional forms along joints and fractures within the granitic rock masses
Gs | Optimum Moisture (%) | Plasticity Index, PI (%) | Plastic limit, PL (%) | Liquid limit, LL (%) | Natural water content (%) | Soil |
2.72 | 15 | 2.54 | 15.09 | 17.63 | 13.84 | A |
2.66 | 11 | 6.33 | 16.11 | 22.44 | 3.02 | B |
Rock type | Water absorption percentage | Point load index | Uniaxial compressive strength | Brazilian tensile strength | Weight loss (5 cycles) |
|
Tuff | Natural | 4.84 | 10.57 | 145 | 21.53 | -0.0172 |
Artificial | 11.48 | 6.19 | 63 | 12/66 | -0.0126 | |
Change rate | ▲ | ▼ | ▼ | ▼ | ▼ | |
Andesite | Nature | 1.35 | 10.48 | 84 | 12.83 | 0.0046 |
Artificial | 8.47 | 1.83 | 34 | 5.86 | -0.0417 | |
Change rate | ▲ | ▼ | ▼ | ▼ | ▲ | |
Granite | Nature | 3.01 | 1.82 | 41 | 10.10 | -0.0032 |
Artificial | 0.42 | 3.56 | 51 | 10.34 | 0.0083 | |
Change rate | ▼ | ▲ | ▲ | ▲ | ▼ |
© 2025 CC BY-NC 4.0 | Journal of Engineering Geology
Designed & Developed by : Yektaweb