scholarly journals Amplification Effect of Ground Motion in Offshore Meandering Sedimentary Valley

2021 ◽  
Vol 2021 ◽  
pp. 1-27
Author(s):  
Hailiang Wang ◽  
Shaomin Yan ◽  
Zhongxian Liu ◽  
Xinglei Cheng
Keyword(s):  
Seismic Response ◽  
Large Scale ◽  
Resonance Effect ◽  
Surface Displacement ◽  
Sedimentary Basins ◽  
River Valley ◽  
Natural Vibration Frequency ◽  
Vibration Direction ◽  
Amplification Effect ◽  
Valley Site

A sedimentary valley has a visible amplification effect on a seismic response, and the current 2D topographies cannot truthfully reflect the twists and turns of a large-scale river valley. Taking a sinusoidal curved valley site as a model, the dynamic finite element analysis method and the introduction of a viscoelastic artificial boundary were developed to study the 3D seismic response of the dimensional topographies in the homogeneous curved valley to vertical incident P, SV, and SH waves. The results showed that the bending sedimentary valley site earthquake presented significant features simultaneously, depending on the number of valley bends, the frequency of the excitations, the shear wave velocity of sedimentary soil, and the depth of the river valley. The surface displacement amplitudes of three-dimensional meandering sedimentary valleys are significantly different from those of sedimentary basins. The amplification area of the meandering valley is related to the angle between the valley axis and wave vibration direction, and the amplification effect is significant when the angle is small. The movement in the main direction showed a center focus, and the secondary y-direction displacement showed both a central focus and an edge effect. When the frequency of the incident wave was close to the natural vibration frequency in a specific direction, the movement in this direction significantly increased because of the resonance effect. The displacement amplitude of the surface was proportional to the depth of the river valley, and the surface displacement was presented in different forms based on the frequency of the excitations. The results provided some guidance for the earthquake resistance of the curved valley site.

Large-scale vegetation mapping of the Pinega river valley (the surroundings of Golubino village, Arkhangelsk oblast)

2018 ◽  
pp. 19-39
Author(s):  
M. A. Makarova
Keyword(s):  
Plant Communities ◽  
Indicator Species ◽  
Dominant Species ◽  
Large Scale ◽  
Vegetation Mapping ◽  
River Valley ◽  
Floodplain Forests ◽  
Floodplain Vegetation ◽  
Wet Meadows ◽  
Arkhangelsk Oblast

Geobotanical survey of floodplain natural complexes near gypsum outcrops in the Pinega river valley was done in 2015. Large-scale geobotanical map of the key polygon (scale 1 : 30 000) was composed. Typological units of vegetation were selected on the basis of the composition of dominant species and groups of indicator species. Homogeneous and heterogeneous territorial units of vegetation (serial series, combinations, environmental series) were used. 53 mapped unit types (25 homogeneous types and 28 heterogeneous types) were recognized. The floodplain vegetation consists of 17 homogeneous types of plant communities, 3 series, 14 combinations and 6 ecological series. The sites of old floodplain forests, such as willow forests with Urtica sondenii rare in the Arkhangelsk region and oxbow wet meadows with Scolochloa festucacea were identified.

scholarly journals Spatiotemporal behavior of a large-scale landslide at Mt. Onnebetsu-dake, Japan, detected by three L-band SAR satellites

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Youichiro Takada ◽  
George Motono
Keyword(s):  
Large Scale ◽  
Fluid Pressure ◽  
Surface Displacement ◽  
Length Change ◽  
Vertical Displacement ◽  
Phase Changes ◽  
Annual Rainfall ◽  
Spatiotemporal Behavior ◽  
Spatially Periodic ◽  
L Band

Abstract We applied differential InSAR analysis to the Shiretoko Peninsula, northeastern Hokkaido, Japan. All the interferograms of long temporal baseline (~ 3 years) processed from SAR data of three L-band satellites (JERS-1, ALOS, ALOS-2) commonly indicate remarkable phase changes due to the landslide movement at the southeastern flank of Mt. Onnebetsu-dake, a Quaternary stratovolcano. The area of interferometric phase change matches to known landslide morphologies. Judging from the timing of the SAR image acquisitions, this landslide has been moving at least from 1993 to the present. Successive interferograms of 1-year temporal baseline indicate the temporal fluctuation of the landslide velocity. Especially for the descending interferograms, the positive line-of-sight (LOS) length change, which indicates large subsidence relative to the horizontal movement, is observed in the upslope section of the landslide during 1993–1998, while the negative LOS change is observed in the middle and the downslope section after 2007 indicating less subsidence. The landslide activity culminates from 2014 to 2017: the eastward and the vertical displacement rates reach ~ 6 and ~ 2 cm/yr, respectively. Utilizing high spatial resolution of ALOS and ALOS-2 data, we investigated velocity distribution inside the landslide. During 2007–2010, the eastward component of surface displacement increases toward the east, implying that the landslide extends toward the east. During 2014–2017, the vertical displacement profile exhibits spatially periodic uplift and subsidence consistent with surface gradient, which indicates the ongoing deformation driven by gravitational force. Heavy rainfall associated with three typhoons in August 2016 might have brought about an increase in the landslide velocity, possibly due to elevated pore-fluid pressure within and/or at the base of the landslide material. Also, annual rainfall would be an important factor that prescribes the landslide velocity averaged over 3 years.

Design and Application of Automatic Monitoring System in Side Slope

2011 ◽  
Vol 243-249 ◽  
pp. 2613-2617 ◽  
Author(s):  
Xiu Guang Song ◽  
Zheng Ma ◽  
Hong Bo Zhang ◽  
Qian Wang ◽  
Pei Zhi Zhuang
Keyword(s):  
Large Scale ◽  
Surface Displacement ◽  
Automatic Monitoring ◽  
Scale Construction ◽  
Low Carbon ◽  
Soil Pressure ◽  
Monitoring Method ◽  
Automatic Monitoring System ◽  
Side Slope ◽  
Project Construction

The field monitoring of dangerous landslide is an important measure for guaranteeing its safety, especially when surrounded by large-scale construction. The landslide located nearby a reservoir in Shandong province. To guarantee construction safety, we adopted the automatic monitoring method for monitoring surface displacement and the internal soil pressure. The whole system uses solar power to provide energy and uses GPRS to transfer data. This system not only can provide reliable information for project construction, but also promote the application of environmentally friendly, low carbon in the monitoring field of civil engineering.

Two-dimensional elastic pseudo-spectral modeling of wide-aperture seismic array data with application to the Wichita Uplift-Anadarko Basin region of southwestern Oklahoma

1990 ◽  
Vol 80 (6A) ◽  
pp. 1677-1695 ◽  
Author(s):  
Ik Bum Kang ◽  
George A. McMechan
Keyword(s):  
Large Scale ◽  
Deep Structure ◽  
Sedimentary Basins ◽  
P Wave ◽  
Two Dimensional ◽  
Anadarko Basin ◽  
Near Surface ◽  
University Of Texas ◽  
Wide Aperture ◽  
The University

Abstract Full wave field modeling of wide-aperture data is performed with a pseudospectral implementation of the elastic wave equation. This approach naturally produces three-component stress and two-component particle displacement, velocity, and acceleration seismograms for compressional, shear, and Rayleigh waves. It also has distinct advantages in terms of computational requirements over finite-differencing when data from large-scale structures are to be modeled at high frequencies. The algorithm is applied to iterative two-dimensional modeling of seismograms from a survey performed in 1985 by The University of Texas at El Paso and The University of Texas at Dallas across the Anadarko basin and the Wichita Mountains in southwestern Oklahoma. The results provide an independent look at details of near-surface structure and reflector configurations. Near-surface (<3 km deep) structure and scattering effects account for a large percentage (>70 per cent) of the energy in the observed seismograms. The interpretation of the data is consistent with the results of previous studies of these data, but provides considerably more detail. Overall, the P-wave velocities in the Wichita Uplift are more typical of the middle crust than the upper crust (5.3 to 7.1 km/sec). At the surface, the uplift is either exposed as weathered outcrop (5.0 to 5.3 km/sec) or is overlain with sediments of up to 0.4 km in thickness, ranging in velocity from 2.7 to 3.4 km/sec, generally increasing with depth. The core of the uplift is relatively seismically transparent. A very clear, coherent reflection is observed from the Mountain View fault, which dips at ≈40° to the southwest, to at least 12 km depth. Velocities in the Anadarko Basin are typical of sedimentary basins; there is a general increase from ≈2.7 km/sec at the surface to ≈5.9 km/sec at ≈16 km depth, with discontinuous reflections at depths of ≈8, 10, 12, and 16 km.

scholarly journals Alalakh: an account of the excavations at Tell Atchana in the Hatay, 1937–1949

2004 ◽  
Author(s):  
Leonard Woolley
Keyword(s):  
Bronze Age ◽  
Large Scale ◽  
River Valley ◽  
Early Bronze Age ◽  
Late Bronze Age ◽  
13Th Century ◽  
Gold Silver

This monograph describes large-scale excavations undertaken by Sir Leonard Woolley from 1937 to 1939, and again from 1946 to 1949, at the site of Alalakh (modern Tell Atchana) – a late Bronze Age city in the Amuq River valley of Turkey's Hatay Province. Described is the evidence of a series of superimposed palaces and temples, town defences, private houses and graves, in 17 archaeological levels reaching from late Early Bronze Age (Level XVII, c. 2200–2000 BC to Late Bronze Age (Level 0, 13th century BC). Supplementary reports describe the architecture and frescoes, sculptures, and portable objects in fired clay, gold, silver, ivory, stone, and glass.

Elasto-Plastic Analysis of Seismic Response of Valve-Hall Structure with Suspension Valves of Large-Scale Converter Station

2011 ◽  
Vol 94-96 ◽  
pp. 1941-1945
Author(s):  
Yi Wu ◽  
Chun Yang ◽  
Jian Cai ◽  
Jian Ming Pan
Keyword(s):  
Seismic Response ◽  
Large Scale ◽  
Seismic Waves ◽  
Tensile Force ◽  
Response Analysis ◽  
Vertical Acceleration ◽  
Seismic Responses ◽  
Seismic Response Analysis ◽  
Finite Element Software ◽  
Plastic Analysis

Elasto-plastic analysis of seismic responses of valve hall structures were carried out by using finite element software, and the effect of seismic waves on the seismic responses of the valve hall structures and suspension equipments were studied. Results show that significant torsional responses of the structure can be found under longitudinal and 3D earthquake actions. Under 3D earthquake actions, the seismic responses of the suspension valves are much more significant than those under 1D earthquake actions, the maximum tensile force of the suspenders is about twice of that under 1D action. The seismic responses of the suspension valves under vertical earthquake actions are much stronger than those under horizontal earthquake actions, when suffering strong earthquake actions; the maximum vertical acceleration of the suspension valves is about 4 times of that under horizontal earthquake actions. It is recommended that the effects of 3D earthquake actions on the structure should be considered in seismic response analysis of the valve hall structure.

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