A note on the wave-passage effects in out-of-plane response of long structures to strong earthquake pulses     

Reza S. Jalali  Mihailo D. Trifunac 《Soil Dynamics and Earthquake Engineering》2011

Elementary consequences of the wave-passage effects are described for out-of-plane response of long structures, excited by SH wave earthquake ground motion pulses propagating along their longitudinal axis. For the passage times in the range of 0.005–0.10 s, the maximum column drifts can increase several folds due to the combined action of out-of-plane and torsional response. Because most of the seismic wave energy do not arrive at a site vertically, the common engineering assumption that it does, leads to nonconservative response estimates.  相似文献   

Uplift response of buried pipelines in saturated sand deposit under earthquake loading     

Reza Saeedzadeh  Nader Hataf 《Soil Dynamics and Earthquake Engineering》2011

Pipelines buried in saturated sand deposits, during earthquake loading could damage from resulting uplift due to excess pore water pressure generation. Several studies have been made to better understand the uplift mechanism and evaluate the effectiveness of mitigating techniques through experiment, but little numerical works have been done to assess the influence of soil properties and field conditions in pipeline floatation. Especially for previously buried pipelines, in order to set the priority for seismic retrofit, evaluating the risk of floatation in each region could be a concern. In this paper, effects of several parameters including dilatancy angle and density ratio of natural soil, diameter and burial depth of pipe, underground water table and thickness of the saturated soil layer on uplift of pipe have been investigated. Results show the prominent role of burial depth in pipe response and that there exits an optimum level for drop of water table to reduce floatation.  相似文献   

Relationships between magnetic susceptibility and heavy metals in urban topsoils in the arid region of Isfahan, central Iran   总被引：4，自引：0，他引：4  

Rezvan Karimi  Shamsollah Ayoubi  Ahmad Jalalian  Ahmad Reza Sheikh-Hosseini  Majid Afyuni 《Journal of Applied Geophysics》2011,74(1):1-7

Electromagnetic induction (EMI) method results are shown for vertical magnetic dipole (VMD) configuration by using the EM38 equipment. Performance in the location of metallic pipes and electrical cables is compared as a function of instrumental drift correction by linear and quadratic adjusting under controlled conditions. Metallic pipes and electrical cables are buried at the IAG/USP shallow geophysical test site in São Paulo City, Brazil. Results show that apparent electrical conductivity and magnetic susceptibility data were affected by ambient temperature variation. In order to obtain better contrast between background and metallic targets it was necessary to correct the drift. This correction was accomplished by using linear and quadratic relation between conductivity/susceptibility and temperature intending comparative studies. The correction of temperature drift by using a quadratic relation was effective, showing that all metallic targets were located as well deeper targets were also improved.  相似文献   

A comparative study of the ATC-40 recommended and numerically derived M-(ψ) relationship     

Sifat Sharmeen Muin  Tahsin Reza Hossain 《地震工程与工程振动(英文版)》2011,10(4)

Nonlinear static analysis procedures are key tools in evaluating the performance of existing buildings and verifying the design of seismic retrofits in seismically active regions.In this procedure,nonlinear force-displacement or moment-curvature (M-(4)) behavior needs to be defined.In the ATC-40 document,values of M-~ have been proposed to model elements in a nonlinear procedure.However,these values need to be investigated to determine if they are representative of actual values.In this paper,an attempt has been made to numerically derive M-（4） curves to simulate actual performance.Then,these curves are compared with the ATC-40 recommended curves with respect to various parameters.The study indicated that ATC-40 suggested values are conservative in nature in most situations.  相似文献   

Left-lateral active deformation along the Mosha–North Tehran fault system (Iran): Morphotectonics and paleoseismological investigations     

Shahryar Solaymani Azad  Jean-François Ritz  Mohammad Reza Abbassi 《Tectonophysics》2011,497(1-4):1-14

The Mosha and North Tehran faults correspond to the nearest seismic sources for the northern part of the Tehran megacity. The present-day structural relationships and the kinematics of these two faults, especially at their junction in Lavasanat region, is still a matter of debate. In this paper, we present the results of a morphotectonic analysis (aerial photos and field investigations) within the central part of the Mosha and eastern part of the North Tehran faults between the Mosha valley and Tehran City. Our investigations show that, generally, the traces of activity do not follow the older traces corresponding to previous long-term dip–slip thrusting movements. The recent faulting mainly occurs on new traces trending E–W to ENE–WSW affecting Quaternary features (streams, ridges, risers, and young glacial markers) and cutting straight through the topography. Often defining en-echelon patterns (right- and left-stepping), these new traces correspond to steep faults with either north- or south-dipping directions, along which clear evidences for left-lateral strike–slip motion are found. At their junction zone, the two sinistral faults display a left-stepping en-echelon pattern defining a positive flower structure system clearly visible near Ira village. Further west, the left-lateral strike–slip motion is transferred along the ENE–WSW trending Niavaran fault and other faults. The cumulative offsets associated with this left-lateral deformation is small compared with the topography associated with the previous Late Tertiary thrusting motion, showing that it corresponds to a recent change of kinematics.  相似文献   

Analytical solutions for the capture zone of a pumping well near a stream     

Mahdi Asadi-Aghbolaghi  Gholam Reza Rakhshandehroo  Mazda Kompani-Zare 《Hydrogeology Journal》2011,19(6):1161-1168

The capture zone for a fully penetrating well in an aquifer with regional flow to a stream boundary under steady-state conditions was delineated using complex algebra and image well theory. Regional flow in the aquifer was allowed to take different directions relative to the stream axis. Two critical pumping rates, Q _C1 and Q _C2, produce three capture-zone pattern scenarios: (1) at low pumping rates (Q?<?Q _C1) water is solely withdrawn from the aquifer and no water from the stream enters the aquifer, (2) at medium pumping rates (Q _C1?<?Q?<?Q _C2) a portion of stream water enters the aquifer but it is not captured by the well, and (3) at high pumping rates (Q?>?Q _C2) pumped water is supplied from both the aquifer and the stream with different proportions. For the second and third scenarios, the stream length interval through which stream water enters the aquifer was determined and found to be more sensitive to pumping rate as the regional flow direction approaches the stream axis. The portion of pumped water supplied by the stream was determined in the third scenario. Finally, the capture-zone asymmetry with respect to its axial line was delineated.  相似文献   

Interrelationship of TOC,As, Fe,Mn, Al and Si in shallow alluvial aquifers in Chapai-Nawabganj,Northwestern Bangladesh: implication for potential source of organic carbon     

A. H. M. Selim Reza  Jiin-Shuh Jean  Ming-Kuo Lee  Shang-De Luo  Jochen Bundschuh  Hong-Chun Li  Huai-Jen Yang  Chia-Chuan Liu 《Environmental Earth Sciences》2011,63(5):955-967

Two boreholes and ten piezometers in the Ganges flood plain were drilled and installed for collecting As-rich sediments and groundwater. Groundwater samples from the Ganges flood plain were collected for the analysis of cations (Ca²⁺, Mg²⁺, K⁺, Na⁺), anions (Cl⁻, NO₃ ⁻, SO₄ ²⁻), total organic carbon (TOC), and trace elements (As, Mn, Fe, Sr, Se, Ni, Co, Cu, Mo, Sb, Pb). X-ray powder diffraction was performed to characterize the major mineral contents of aquifer sediments and X-ray fluorescence (XRF) to analyze the major chemical composition of alluvial sediments. Results of XRF analysis clearly show that fine-grained sediments contain higher amounts of trace element because of their high surface area for adsorption. Relative fluorescence index (15–38 QSU) of humic substance in groundwater was measured using spectrofluorometer, the results revealed that groundwater in the Ganges flood plain contains less organic matter (OM). Arsenic concentration in water ranges from 2.8 to 170 μg/L (mean 50 μg/L) in the Ganges flood plain. Arsenic content in sediments ranges from 2.1 to 14 mg/kg (mean 4.58 mg/kg) in the flood plains. TOC ranges from 0.49 to 3.53 g/kg (mean 1.64 g/kg) in the Ganges flood plain. Arsenic is positively correlated with TOC (R ² = 0.55) in sediments of this plain. Humic substances were extracted from the sediments from the Ganges flood plain. Fourier transform infrared analysis of the sediments revealed that the plain contains less humic substances. The source of organic carbon was assigned from δ¹³C values obtained using elemental analysis-isotope ratio mass spectrometry (EA-IRMS); the values (−10 to −29.44‰) strongly support the hypothesis that the OM of the Ganges flood plain is of terrestrial origin.  相似文献   

Application of the spectral decomposition technique for characterizing reservoir extensional system in the Abadan Plain, southwestern Iran     

Mohammad Reza SaadatinejadKhalil Sarkarinejad 《Marine and Petroleum Geology》2011,28(6):1205-1217

The Abadan plain in southwestern Iran has important petroleum reservoir potential but poorly defined structural setting. It is located at the Mesopotamian foredeep basin, bounded by the Arabian plate and the Dezful Embayment. The main reservoir in this field is the Fahliyan formation, composed of reef carbonates. Most of the Abadan area is flat and covered by recent alluvial deposits with no outcrops. Studies of the structures in this area have provided information about the structural history and allowed better reservoir and drilling management. Seismic spectral decomposition techniques have been utilized as a quick and effective interpretation tool. Fast Fourier transform (FFT) and continuous wavelet transforms (CWT) have been used to convert time to frequency domain, and have been applied to detect fault systems in the reservoir. Application of the Fast Fourier transform (FFT) and continuous wavelet transforms (CWT) indicate that the Abadan reservoir consists normal extensional system of the reservoir which display paralleling of contour common depth in two sides of extensional system in some regions and large displacement between two sides of contours indicate that system is normal in which hanging wall moved over footwall. Various displacements between sides indicate parallel strike-slip movements which are associated with reverse faulting and inversion tectonics.  相似文献   

Comparison of IWG and SDSM weather generators for climate change impact assessment     

Khazaei  Mohammad Reza  Zahabiyoun  Bagher  Hasirchian  Mehraveh 《Theoretical and Applied Climatology》2020,140(3):859-870

Theoretical and Applied Climatology - Weather generators (WGs) typically have unique advantages to the climate change impacts assessment. However, each of them has the weaknesses, strengths, and...  相似文献   

Time evolution of nonplanar electron acoustic shock waves in a plasma with superthermal electrons     

Hamid Reza Pakzad  Kurosh Javidan  Mouloud Tribeche 《Astrophysics and Space Science》2014,352(1):185-191

The propagation of cylindrical and spherical electron acoustic (EA) shock waves in unmagnetized plasmas consisting of cold fluid electrons, hot electrons obeying a superthermal distribution and stationary ions, has been investigated. The standard reductive perturbation method (RPM) has been employed to derive the cylindrical/spherical Korteweg-de-Vries-Burger (KdVB) equation which governs the dynamics of the EA shock structures. The effects of nonplanar geometry, plasma kinematic viscosity and electron suprathermality on the temporal evolution of the cylindrical and spherical EA shock waves are numerically examined.  相似文献