Fardin Jafarzadeh - Academia.edu (original) (raw)

Papers by Fardin Jafarzadeh

One of the most important concerns in designing an embankment dam is seepage analysis. Convention... more One of the most important concerns in designing an embankment dam is seepage analysis. Conventional seepage analyses of embankment dams a r e performed in two-dimensional (2D) space, in which the impacts of water ow lines seeping from the side abutments a r e ignored. This fact is especially important if the dam is constructed in a narrow valley. In addition, if the e ects of existing underlain faults in the reservoir water discharge rate, under di erent loading conditions, are to be scrutinized, three-dimensional (3D) modeling of the dam for seepage analysis is inevitable. In this paper, the signi cance of three-dimensional seepage analyses is emphasized by making a 3D model of a real dam site. The assumed 3D model contains all details of the rock-ll dam body and its foundation and abutments. Also, all ground improving methods for the water tightening of the underlain faults have been considered. The 3D steady state seepage analysis results were compared to those of a 2D analysis, from di erent points of view, indicating that when a dam is designed for a narrow valley, performing a 3D seepage analysis is vital, due to the widthwise water ow from the side abutments. Several sensitivity analyses were also performed to show the e ect of uncertainty in evaluating the characteristics of side abutment grouting curtains in seepage analysis results.

Landslides, liquefaction, wave propagation and faulting are four major earthquake induced hazards... more Landslides, liquefaction, wave propagation and faulting are four major earthquake induced hazards to lifelines. Although, there are a few guidelines for pipeline design against liquefaction; a reliable design code or guidelines considering the effects of all mentioned phenomena are not available and more studies are required. Therefore, many investigations and studies on special subjects like faulting and land sliding are in progress. In this study, potential slides in Tehran and their geometrical, geotechnical and structural specifications are selected. A buried steel gas pipes with 24 inch diameter is considered as structure and its performance against a local slope is numerically analyzed by ABAQUS program. The slope has 30 degree inclination and is composed of sedimentary cemented soils. A 0.5 g amplitude sinusoidal excitation, equivalent to a 8.5 moment magnitude earthquake, was imposed to models. The pipe having three positions in the slope, is taken perpendicular to sliding. ...

Not only do Pipelines, as routes to convey energy (gas and oil), have significant role in countri... more Not only do Pipelines, as routes to convey energy (gas and oil), have significant role in countries economy, but also tie intercontinental relations by economic collaborations. Therefore, governments annually allot budgets to ensure their safety and permanent operation against unpredicted events. Consequently, many researches have been performed on the task and many methods have been suggested to guarantee their function and to prevent their failure during PGDs. However, not limited to, but PGDs are principally caused by dynamic loading, particularly earthquakes, which have resulted unrestricted damages to pipelines everywhere and unfortunately, these destructions have led to devastative results when the pipes have been buried in potential landslides. Tehran, Iran's capital, which is constructed on either soil or rock slopes, are in danger of landslides and consequent gas pipe damages during earthquakes. In this regard, Sharif University of technology, have performed several dyn...

Congrès annuel et assemblée générale annuelle SCGC 2007 Yellowknife, Northwest Territories / Yell... more Congrès annuel et assemblée générale annuelle SCGC 2007 Yellowknife, Northwest Territories / Yellowknife, Territoires du nord-ouest June 6-9, 2007 / 6 au 9 juin 2007 ABSTRACT It seems that probably the most important cause of instability of embankment dams is the occurrence of liquefaction during strong ground motions. At the present, there is a common approach to assess the liquefaction potential of soils, namely the simplified procedure using the shear wave velocity developed in the course of following decades. In this paper, liquefaction evaluation procedure with case study of Silveh dam foundation using shear wave velocity measurements is discussed. Silveh earth-storage dam, with 102 m height; is under construction in North-West of Iran. Due to numerous and various tectonic occurrences, the area of dam site is known as one of high activity zones and earthquake-prone regions of Iran. In purposed location of dam, alluvium foundation contains mostly fine to medium sand with maximum...

Renewable Energy, 2021

Abstract There is an increasing interest and use of energy foundation worldwide. Full-scale tests... more Abstract There is an increasing interest and use of energy foundation worldwide. Full-scale tests, physical model tests at one Earth’s gravity and at elevated gravity in a geotechnical centrifuge and numerical simulations have been widely reported in the literature. Almost all studies have focused on single energy piles (EPs) and pile groups subjected to symmetrical thermal loads, although it is not unusual to have energy pile groups stressed by non-symmetrical thermal loads. In this study, a series of non-symmetrical thermal loading centrifuge model tests were conducted in saturated soft clay (OCR = 1.7), which is much vulnerable to temperature changes. The tests aim to investigate the effects of pile spacing on the serviceability of floating energy pile groups. Fifteen cycles of non-symmetrical thermal loading are applied to three EPs in 2 x 2 elevated energy pile groups with 3D and 5D (D denotes pile diameter) pile spacing. The thermally induced irreversible settlement and tilting in the 3D-pile group are 200% and 300% larger than those in the 5D one, respectively. Contrary to the 5D-pile group where the serviceability criteria (EN 1997-1:2004) are satisfied, the settlement and tilting are 30% and 200% larger than the criteria in the 3D one, respectively.

For investigating floor heave behavior and controlling technique of roadway intersection in deep ... more For investigating floor heave behavior and controlling technique of roadway intersection in deep mine, creep deformation characteristics of floor around roadway intersection was studied by Flac and the effects of shear plastic critical value, reinforcement measurement on creep deformation of floor around roadway intersection were discussed. As a result, the creep deformation curve can be divided into two stages including initial creep deformation stage and softening deformation stage, which can explain the case that deformation of roadway intersection is little before a certain time, but then increases at a high speed; only when total shear plastic value exceeds the critical value can second creep stage take place; reinforcement measurement with bolting in roof and ribs has little effect on floor heave, yet exerting pressure against floor can reduce floor heave obviously.

Experimental results to investigate the dynamic behavior and impedance function of foundations re... more Experimental results to investigate the dynamic behavior and impedance function of foundations resting on a sand layer are presented in this paper. Physical model block vibration tests were carried out in a cubic steel container of size 1.0 m×1.0 m×0.8 m using foundations in three shapes, circular, square, and rectangular. The radius of the circular one was 7.5 cm and the two other types had the same radius of the equivalent circle, where the aspect ratio of the rectangular foundation was L/B = 2. The employed vertical force generator was a vibration exciter system, driven by a power amplifier. Using available sea sand, a sandy sample with specific density was prepared, and tests were carried out for three different footing shapes, by varying contact pressure and causing embedment for footing. The impedance functions for the different above conditions were calculated and compared with the preceding numerical and experimental works. It was observed that the stiffness and damping of t...

Tunnelling and Underground Space Technology, 2005

Taylor & Francis eBooks, Jul 12, 2006

The international journal hydropower & dams, 2005

Scientia Iranica, Feb 5, 2023

Problems associated with soil-structure interaction have been determined and the Impendence Funct... more Problems associated with soil-structure interaction have been determined and the Impendence Functions evaluated. The aim of this paper is studying horizontal impedance function for surface footings by physical model tests. For this purpose, a cubic steel container was used as a testing environment for two different conditions, a rigid base, and a homogeneous half-space model. The effect of various parameters such as footing shape, embedment ratio, inertia, and dynamic force amplitude was studied in three shapes; rectangular, square, and circle footing. The results indicated that the massless impedance function theory was confirmed at the Dimensionless Frequency of less than 2.5. Also, in the rigid base model, soil response heavily depends on the vibration frequency, developed by boundary conditions and side walls, in contrast to the half-space model. The rigid base, distribution and reflection of waves in the soil, and dissipation of higher wave energy substantially influenced the dynamic response of soil-foundation system. Additionally, the embedment ratio significantly affected the impedance functions.

Renewable Energy, 2021

Tunnelling and Underground Space Technology, 2005

Taylor & Francis eBooks, Jul 12, 2006

The international journal hydropower & dams, 2005

Scientia Iranica, Feb 5, 2023