scholarly journals Size distribution law of earthquake-triggered landslides in different seismic intensity zones

2020 ◽  
Author(s):  
Yidan Huang ◽  
Lingkan Yao
Keyword(s):  
Power Law ◽  
Lognormal Distribution ◽  
Remote Sensing Data ◽  
Seismic Intensity ◽  
Shaking Table ◽  
Distribution Law ◽  
Ground Acceleration ◽  
Dynamical Mechanism ◽  
Negative Power ◽  
Sand Pile

Abstract. The Ms 8.0 Wenchuan earthquake in 2008 and Ms 7.0 Lushan earthquake in 2013 produced thousands of landslides in the southern region of the Longmen Mountains in China. We conducted field investigations and analyzed remote sensing data to determine the distribution law of earthquake-triggered landslides. The results show a strong negative power-law relationship between the size and frequency of landslides in VII, VIII, and IX seismic intensity zones, a weak power law in the X seismic intensity zone, and a lognormal distribution in the XI seismic intensity zone. Landslide density increases with increasing seismic intensity. A sand pile cellular automata model was built under the conceptual framework of self-organized criticality theory to simulate earthquake-induced landslides. Data from the simulations demonstrate that with increasing disturbance intensity, the dynamical mechanism of the sand pile model changes from a strong power law to a weak power law and then to a lognormal distribution. Results from shaking table experiments of a one-sided slope sand pile show that for peak ground acceleration (PGA) in the range of 0.075 g–0.125 g, the relation between the amount and frequency of sand follows a negative power law. For PGA between 0.15 g and 0.25 g, the relation obeys a lognormal distribution. This verifies that the above-mentioned distribution of earthquake-induced landslides should be a universal law from a physical viewpoint and may apply to other areas. This new perspective may be used to guide development of an inventory of earthquake-triggered landslides and provide a scientific basis for their prediction.

scholarly journals Size distribution law of earthquake-triggered landslides in different seismic intensity zones

2021 ◽  
Vol 28 (2) ◽  
pp. 167-179
Author(s):  
Yidan Huang ◽  
Lingkan Yao
Keyword(s):  
Power Law ◽  
Lognormal Distribution ◽  
Remote Sensing Data ◽  
Scientific Basis ◽  
Seismic Intensity ◽  
Shaking Table ◽  
Distribution Law ◽  
Ground Acceleration ◽  
Dynamical Mechanism ◽  
Negative Power

Abstract. The Ms 8.0 Wenchuan earthquake in 2008 and Ms 7.0 Lushan earthquake in 2013 produced thousands of landslides in the southern region of the Longmen Mountains in China. We conducted field investigations and analyzed remote sensing data to determine the distribution law of earthquake-triggered landslides. The results show a strong negative power law relationship between the size and frequency of landslides in VII, VIII, and IX seismic intensity zones, a weak power law in the X seismic intensity zone, and a lognormal distribution in the XI seismic intensity zone. Landslide density increases with increasing seismic intensity. A sandpile cellular automata model was built under the conceptual framework of self-organized criticality theory to simulate earthquake-induced landslides. Data from the simulations demonstrate that, with increasing disturbance intensity, the dynamical mechanism of the sandpile model changes from a strong power law to a weak power law and then to a lognormal distribution. Results from shaking table experiments of a one-sided slope sandpile show that, for peak ground acceleration (PGA) in the range of 0.075–0.125 g, the relation between the amount and frequency of sand follows a negative power law. For PGA between 0.15 and 0.25 g, the relation obeys a lognormal distribution. This verifies that the abovementioned distribution of earthquake-induced landslides should be a universal law from a physical viewpoint and may apply to other areas. This new perspective may be used to guide the development of an inventory of earthquake-triggered landslides and provide a scientific basis for their prediction.

scholarly journals Global variability of phytoplankton functional types from space: assessment via the particle size distribution

2010 ◽  
Vol 7 (3) ◽  
pp. 4295-4340 ◽  
Author(s):  
T. S. Kostadinov ◽  
D. A. Siegel ◽  
S. Maritorena
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Power Law ◽  
Seasonal Succession ◽  
Remote Sensing Data ◽  
Good Correspondence ◽  
Size Classes ◽  
Functional Types ◽  
Phytoplankton Size

Abstract. A new method of retrieving the parameters of a power-law particle size distribution (PSD) from ocean color remote sensing data was used to assess the global distribution and dynamics of phytoplankton functional types (PFT's). The method retrieves the power-law slope, ξ, and the abundance at a reference diameter, N0, based upon the shape and magnitude of the particulate backscattering coefficient spectrum. Relating the PSD to PFT's on global scales assumes that the open ocean particulate assemblage is biogenic. The retrieved PSD's can be integrated to define three size-based PFT's by the percent volume concentration contribution of three phytoplankton size classes – picoplankton (0.5–2 μm in equivalent spherical diameter), nanoplankton (2–20 μm) and microplankton (20–50 μm). Validation with in-situ HPLC diagnostic pigments results in satisfactory match-ups for the pico- and micro-phytoplankton size classes. Global climatologies derived from SeaWiFS monthly data reveal PFT and particle abundance spatial patterns that are consistent with current understanding. Oligotrophic gyres are characterized by lower particle abundance and higher contribution by picoplankton-sized particles than transitional or eutrophic regions. Seasonal succession patterns for size-based PFT's reveal good correspondence between increasing chl and percent contribution by microplankton, as well as increasing particle abundance. Long-term trends in particle abundances are generally inconclusive yet are well correlated with the MEI index indicating increased oligotrophy (i.e. lower particle abundance and increased contribution of picoplankton-sized particles) during the warm phase of an El Niño event. This work demonstrates the utility and future potential of assessing phytoplankton functional types using remote characterization of the particle size distribution.

scholarly journals Динаміка розмірів сільськогосподарських полів як функція їх розмірів та форми

2007 ◽  
Vol 7 (3) ◽  
pp. 14-31
Author(s):  
O.V. Zhukov ◽  
V.O. Sirovatko ◽  
N.O. Ponomarenko
Keyword(s):  
Regression Analysis ◽  
Large Scale ◽  
Remote Sensing Data ◽  
Field Size ◽  
Agricultural Fields ◽  
Distribution Law ◽  
Administrative Area ◽  
Log Normal ◽  
Shape Characteristics ◽  
Shape And Size

<p>We estimated the size and shape characteristics of agricultural fields within the administrative area and identified patterns of the margin trends from 1950-1960 till the present time. Here we considered large-scale soil maps for the area of Vasilkovsky district of the Dnepropetrovsk region, which were drawn up in 1950-1960. To assess the landscape metric we used FRAGSTATS program which allow to make conformity assessment of the observed distributions of field sizes regards the normal, exponential, log-normal, gamma, Weibull, and Pareto distributions. We also used Box-Cox transformation to convert the experimental data into the normal distribution law for the further application of the transformed data in regression analysis. We estimated that the area of agricultural fields ranged from 1.20 to 269.00 hectares during the period of large-scale mapping in 1950-1960. The variation limits of the field sizes based on the results of remote sensing data and in our time they are 2,.5-266.57 hectares. Area of the fields in different periods strongly correlate and are statistically significant (<em>r</em> = 0.98, <em>p</em> = 0.00). Field sizes currently associated with the field sizes in the 50-60 years of linear regression. Shape parameters and field sizes significantly correlated, therefore, to establish the main trends of varying shape and size of fields, as well as for non-multicollinearity variables for regression analysis, we performed a multivariate factor analysis. An important aspect of the structuring of the agri-landscape is the location of settlements and, therefore, the fields distance from them. In results obtained indicate that the processes increase and decrease the size of fields in agricultural production are determined by various factors. Aspects of the shape and size of the fields associated with the dynamics of the processes that lead to variations in field areas. Fields that have shown a tendency to change their size, have different characteristics of forms and size from the stable fields. Typically, variable field size is smaller and more complex shapes.</p>

scholarly journals Effect of Soil Box Boundary Conditions on Dynamic Behavior of Model Soil in 1 g Shaking Table Test

2020 ◽  
Vol 10 (13) ◽  
pp. 4642
Author(s):  
Hoyeon Kim ◽  
Daehyeon Kim ◽  
Yonghee Lee ◽  
Haksung Kim
Keyword(s):  
Boundary Conditions ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Boundary Effects ◽  
Soil Behavior ◽  
Ground Acceleration ◽  
Various Boundary Conditions ◽  
Model Soil ◽  
Shear Box ◽  
Laminar Shear

In order to evaluate the effects of soil box boundary conditions on the dynamic soil behavior, the Rigid Box (RB) and the Laminar Shear box (LSB) were constructed and 1 g shaking table tests were carried out for various boundary conditions. The boundary effects of the RB and the LSB were compared. To reduce the boundary effects of the RB, sponges, 5 cm, 10 cm, and 15 cm in thickness, were attached to the two end sides of the RB. A model soil was constructed on flat ground, and the acceleration and amplification occurring in the center of the soil were analyzed by spectrum and peak ground acceleration. Compared with the RB, the center and wall accelerations of LSB were very close to each other. This implies that the LSB can better simulate the behavior of the infinite half space than the RB.

Shaking Table Tests of Critical Equipment With Simple Isolators

2006 ◽  
Author(s):  
C. S. Tsai ◽  
Wen-Shin Chen ◽  
Shih-Hsien Yu ◽  
Chen-Tsung Yang
Keyword(s):  
Shaking Table ◽  
Original Position ◽  
Economic Losses ◽  
High Tech ◽  
Shaking Table Tests ◽  
Restoring Force ◽  
Ground Acceleration ◽  
Maximum Displacement ◽  
Natural Period ◽  
Energy Absorbing

Because the earthquake is one kind of non-predictable calamity and happens suddenly, its disaster and consequence are larger than other calamities. Mankind must face not only the emotional effects caused by earthquakes, but also the damage to the structure and substructure systems. The fire, damaged pipeline systems cased by earthquake and the destruction of the semiconductor, equipment or microelectronics in high-tech factories will cause an enormous and a chain of economic losses. Therefore, there is a need of an economical and efficient method to protect equipments from earthquake damage. Namely, in addition to promoting the earthquake-resistant capacity of structures, it is also important to ensure the safety of the expensive equipment and facilities. In this study, it is aimed at developing a new simple isolator with appropriate damping for critical equipment. The basic principle of the simple isolator is to lengthen the natural period of equipment, and simultaneously to reduce the earthquake-induced energy and the displacement of the isolator by additional damping. A series of shaking table tests for critical equipment isolated with simple isolators were carried out in the Department of Civil Engineering, Feng Chia University, Taichung, Taiwan. From these test results, it is illustrated that the simple isolator can reduce more than 80% responses of accelerations under earthquakes with peak ground acceleration of above 0.450g. Therefore, the simple isolator can be recognized as a feasible and promising way in mitigating the seismic responses of equipment. In addition, the simple isolator possesses enough energy absorbing capacity to reduce its maximum displacement and the restoring force to bring the isolator back to the original position without significant residual displacement.

scholarly journals Seismic Response of a Bridge Pile Foundation during a Shaking Table Test

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Yunxiu Dong ◽  
Zhongju Feng ◽  
Jingbin He ◽  
Huiyun Chen ◽  
Guan Jiang ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Pile Foundation ◽  
Large Scale ◽  
Amplification Factor ◽  
Shaking Table Test ◽  
Seismic Intensity ◽  
Shaking Table ◽  
Acceleration Amplification ◽  
Bedrock Surface ◽  
Bridge Pile Foundation

Puqian Bridge is located in a quake-prone area in an 8-degree seismic fortification intensity zone, and the design of the peak ground motion is the highest grade worldwide. Nevertheless, the seismic design of the pile foundation has not been evaluated with regard to earthquake damage and the seismic issues of the pile foundation are particularly noticeable. We conducted a large-scale shaking table test (STT) to determine the dynamic characteristic of the bridge pile foundation. An artificial mass model was used to determine the mechanism of the bridge pile-soil interaction, and the peak ground acceleration range of 0.15 g–0.60 g (g is gravity acceleration) was selected as the input seismic intensity. The results indicated that the peak acceleration decreased from the top to the bottom of the bridge pile and the acceleration amplification factor decreased with the increase in seismic intensity. When the seismic intensity is greater than 0.50 g, the acceleration amplification factor at the top of the pile stabilizes at 1.32. The bedrock surface had a relatively small influence on the amplification of the seismic wave, whereas the overburden had a marked influence on the amplification of the seismic wave and filtering effect. Damage to the pile foundation was observed at 0.50 g seismic intensity. When the seismic intensity was greater than 0.50 g, the fundamental frequency of the pile foundation decreased slowly and tended to stabilize at 0.87 Hz. The bending moment was larger at the junction of the pile and cap, the soft-hard soil interface, and the bedrock surface, where cracks easily occurred. These positions should be focused on during the design of pile foundations in meizoseismal areas.

scholarly journals Seismic Response of Aeolian Sand High Embankment Slopes in Shaking Table Tests

2019 ◽  
Vol 9 (8) ◽  
pp. 1677 ◽  
Author(s):  
Zhijun Zhou ◽  
Jiangtao Lei ◽  
Shaobo Shi ◽  
Tong Liu
Keyword(s):  
Seismic Waves ◽  
Shear Failure ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Aeolian Sand ◽  
Distribution Law ◽  
Horizontal Acceleration ◽  
Reflected Wave ◽  
Increasing Trend ◽  
Three Stages

Aeolian sand high embankments are always damaged by earthquakes; however, little research has addressed this so far. In this study, shaking table tests were conducted on three aeolian sand high embankment models. Based on the shear failure mechanism of aeolian sand, the seismic responses of model embankments were analyzed. When seismic waves were inputted, the horizontal acceleration magnification (HAM) of three models always exceeded 1.0, and showed an increasing trend with height. Furthermore, according to the HAM change rules of three models under different input peak accelerations, the destruction of model embankments under earthquakes includes three stages: the reflected wave emergence (RWE) stage, the reflected wave strengthening (RWS) stage, and the acceleration magnification attenuation (AMA) stage. According to this definition, models with slopes of 1/1.2 and 1/0.8 experienced all three stages during tests, and the critical horizontal acceleration transform from the RWS stage to the AMA stage appeared. The model with a slope of 1/1.5 only experienced RWE and RWS stages during the test. At the end of the tests, the macroscopic instability mechanisms of all three models were studied, which were found to match the distribution law of HAM during tests and the destruction stage definition.

Modeling cliff erosion using negative power law scaling of rockfalls

Geomorphology ◽  
2012 ◽  
Vol 139-140 ◽  
pp. 416-424 ◽  
Author(s):  
John Barlow ◽  
Michael Lim ◽  
Nick Rosser ◽  
David Petley ◽  
Matthew Brain ◽  
...  
Keyword(s):  
Power Law ◽  
Negative Power ◽  
Cliff Erosion

EXPERIMENT SYSTEM BY VIRTUAL SHAKING TABLE USING ACCELEROMETER

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Terumasa Okamoto ◽  
Osamu Tsujihara
Keyword(s):  
Degrees Of Freedom ◽  
Serial Communication ◽  
Seismic Intensity ◽  
Shaking Table ◽  
Earthquake Resistance ◽  
Structure Model ◽  
Communication Interface ◽  
Natural Period ◽  
Experiment System ◽  
Hands On

This paper introduces an experiment system developed as a teaching material to support the lessons related to vibration and earthquake resistance in the fields of civil engineering and architecture. The hardware was composed of an accelerometer, a serial communication interface, an RS232-USB conversion adapter, and a computer. The virtual shaking table in a computer display was controlled by the hand-operated accelerometer. The response of the structure model with multi-degrees of freedom on the shaking table was calculated in real time. The findings were that hands-on experience in controlling the shaking table helps an instinctive understanding of vibration, especially acceleration and seismic intensity. A structure model with different dynamic characteristics can be built easily, so that the effect of properties, such as the natural period and damping constant on the structural motions, can be visualized, helping the understanding of the theory of vibration.

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