Sharif Digital Repository

Landslides, like earthquakes, floods, and volcanoes, are important natural disasters that occur frequently in the mountainous and high regions of our country, especially in the Alborz and Zagros regions, which induce considerable damages. Various factors such as topography, lithology, weather conditions, hydrology, tectonics, earthquakes, and various human activities are effective factors in the instability of natural and man-made slopes. Not one factor can cause instability in slops, however, a combination of the named factors may cause landslides. Therefore, knowing the factors affecting the occurrence of landslides and identifying different areas in terms of sensitivity to their... 

Landslide is a natural hazard associated with economic losses and fatalities. The geometric of the slope, the soil properties, hydrological factors, and groundwater are important factors that affect the stability of a slope. The landslide investigation is important due to the identification and prevention of damages. Thus, more researchers studies on this subject. The new questions in this field are “how can simulate the vegetation effects in slope stability analysis?” and “what effects do precipitation and infiltration have on landslide triggering?”. Although the classic methods of slope stability analysis provide the initial information for the design, they have limitations in answering... 

The purpose of this research is to study the effect of using expanded polystyrene (EPS) Geofoam to retrofit buried pipelines in slopes subjected to landslide due to earthquakes.For this purpose, several 3D numerical models were built with ABAQUS/CAE based on physical model tests conducted on shaking table device at Sharif University of Technology by previous research groups. Two parts are considered in this study. in the first part, three tests were simulated. Displacements, acceleration time histories and strains of pipes were compared to the tests results and the effect od EPS block on each pipe pesponse was observed. In the second part, effect of two factors on response of buried pipes... 

This thesis intends to evaluate the effect of landslides on dynamic response of soil slopes and buried pipelines. The core findings of the research are itemized as below: According to the experiments, dynamic slope response which moderately develops at deeper depths at toe and lower section, displays a clear downtrend at upper section and crest. Also, the pipe response depends on pipe route and slope displacement pattern. The pipe deformations have positive correlation with depth at upper section and crest, but show opposite behavior at toe and lower section. Moreover, the horizontal strains impact on total strains in buried pipes reduces at greater depths.The pipe strain analysis shows that... 

Evaluation of seismic slope stability is very important because it has a decisive role in estimating the earthquake damages. According to the past studies medium to large earthquakes, usually cause thousands landslides and many casualties and financial damages. Since nearly half a century ago, several methods have been developed for predicting the occurrence of landslides and permanent movements, but due to the influence of many parameters on the seismic stability of the slopes further researches is needed.In present study, to investigate the dynamic behavior of the slopes, three physical models of slopes had been made on shaking table in Sharif University of technology. These slopes have... 

Potential landslides located in the borders of each water body may generate massive and destructive impulsive waves called landslide-generated waves (LGWs) which can be a major threat to human life and his possessions, offshore and coastal installations, dam bodies and hydraulic structures. This research is devoted to numerical modeling of LGW hazards with focus on the impulse wave generation stage including landslide movement, landslide/water surface interactions and consequent tsunami generation. The main purpose of this work is to study the effects of landslide deformability on the impulsive wave characteristics numerically in an introduced state-of-the-art numerical structure. The... 

Evaluation of seismic slope stability is very important because it has a decisive role in stimating the earthquake damages. According to the past studies, medium to large earthquakes usually cause thousands landslides and many casulties and financial damages. Since nearly half a century ago, several methods have been developed for predicting the occurrence of landslides and permanent movements, but due to the influnce of many parameters on the seismic stability of the slopes further researches is needed.
In present study, to investigate the dynamic behavior of the slopes, four physical models of slopes had been made on shaking table in Sharif university of technology. These slopes have 3... 

The purpose of this dissertation is investigation of dynamic behavior of buried pipelines in slopes in landslide. For this purpose four physical models were made on shaking table of Sharif University of Technology. In each of the models some pipes were buried in slope. In these models the pipes were placed in different angles regarding to slope direction. Simulation laws suggested by Iai (1989) were used in these models. Babolsar sand was used for modeling the slopes. Aluminium pipes with outside diameter of 16 millimeters and thickness of 1 millimeter were implemented to model steel pipelines. In this investigation simple supports were used at the end of the pipes, considering the... 

Buried pipelines might pass slopes that are stable in static condition but slope dicplacements due to dynamic loading can result in pipeline failure. There are various factors that influence 3D slope stability under seismic loading condition.In this dissertation , we used finite element software ABAQUS (ver.6.10) to study pipeline performance in such condition. Dynamic analysis on pipe with burial depth of 1.5m that passes a 3D slope was performed by using the time history of sinusidinal loading. Boundary conidion of slope and pipe affects the slope dicplacement and pipeline performance. In different routes that pipe passes slope, pipeline response to slope displacement has been compared... 

Moderate to large magnitude earthquakes trigger hundreds to thousands of slope stability failures and landslides in coherent masses. In many earthquakes, landslides have been responsible for as much or more damage than all other seismic hazards combined. Earthquake-induced landslides have a detrimental impact on the serviceability of slopes by damaging nearby structures, roadways, utilities, power lines and communication networks. In this research large-scale shaking table model tests were conducted to study slope behavior under earthquake conditions on Sharif University shaking table. The model slopes were installed into a model box with a length of 3 m, width of 1 m, and height of 1.5 m. A... 

In this dissertation, the response of buried pipelines in slopes which have become unstable during earthquake induced landslides is investigated. The Sharif University of Technology shaking table was used for modeling this phenomenon.Three tests were performed so that in the first and second ones, three pipes were placed in different positions due to slope and the supports were elastic cylinders. In third test, there were four pipes with simple supports at the test-box walls.The pipes in every test were buried in the depth of 11 centimeters and they were all made of aluminum with the outside diameter of 16 millimeters and thickness of 1 millimeter. Also, they were all in the bending mode due... 

This study presents an integrated two-dimensional numerical framework for simulating rainfall-induced landslides from instability initiation to post-failure flow. The discrete element method (DEM) is used to establish a rheological model that relates the apparent viscosity of a granular sand to shear rate, normal stress, and water saturation. A theoretical model is developed to determine water distribution and water-induced forces between particles for different saturations. The resulting forces are embedded in a 3D shear cell as a numerical rheometer and a wet sand is sheared between two walls. A power law rheological model is obtained as a function of inertia number and saturation. It was...