scholarly journals The Dynamic Amplification Effect of A Site with Earth Fissures: A Case Study in the Taiyuan Basin, China

2021 ◽  
Author(s):  
Jiang Chang ◽  
Yahong Deng ◽  
Ge Cao ◽  
You Xuan ◽  
Nainan He ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Hanging Wall ◽  
Spectral Ratio ◽  
Earth Fissure ◽  
Amplification Effect ◽  
Response Characteristics ◽  
Earth Fissures ◽  
The Earth ◽  
A Site ◽  
Taiyuan Basin

Abstract As a widespread geological hazard, the disaster development process of earth fissures is irreversible and difficult to control, which seriously affects the construction and safe operation of engineering facilities. However, few clear conclusions and special regulations have been given regarding the influence of earth fissures on the dynamic response characteristics of a site and earthquake prevention and disaster reduction measures. Therefore, the microtremor was used instead of earthquake motions to reveal the dynamic response of a site with fissures. The earth fissures in the Taiyuan Basin, which exhibit a large amount of activity, were used as examples. In order to reveal the dynamic response from several aspects, four methods, including the Fourier spectrum, the horizontal-to-vertical spectral ratio (HVSR), the response acceleration, and the Arias intensity, were employed. The results show that the spectrum peaks increase sharply at an earth fissure and return to a stable value approximately 20–25 m away from the fissure, indicating that the earth fissures have an amplification effect on the dynamic response of the site. Additionally, a greater amplification occurs on the hanging wall of the earth fissure. The influence range of the dynamic response of site can be divided into four areas. Suggestions on the seismic fortification intensity and setback distances were also proposed. The amplification mechanism was summarized as the coupling of the changes in the soil properties caused by earth fissure activity, the catadioptric effect of the earth fissure interface, and the multiple amplifications caused by secondary fissures.

scholarly journals Characterization of earth fissures in South Jiangsu, China

2015 ◽  
Vol 372 ◽  
pp. 249-253 ◽  
Author(s):  
S. Ye ◽  
Y. Wang ◽  
J. Wu ◽  
P. Teatini ◽  
J. Yu ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Earth Fissure ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Earth Fissures ◽  
The Earth ◽  
Cumulative Length ◽  
Differential Land Subsidence

Abstract. The Suzhou-Wuxi-Changzhou (known as "Su-Xi-Chang") area, located in the southern part of Jiangsu Province, China, experienced serious land subsidence caused by overly exploitation of groundwater. The largest cumulative land subsidence has reached 3 m. With the rapid progress of land subsidence since the late 1980s, more than 20 earth fissures developed in Su-Xi-Chang area, although no pre-existing faults have been detected in the surroundings. The mechanisms of earth fissure generation associated with excessive groundwater pumping are: (i) differential land subsidence, (ii) differences in the thickness of the aquifer system, and (iii) bedrock ridges and cliffs at relatively shallow depths. In this study, the Guangming Village Earth Fissures in Wuxi area are selected as a case study to discuss in details the mechanisms of fissure generation. Aquifer exploitation resulted in a drop of groundwater head at a rate of 5–6 m yr−1 in the 1990s, with a cumulative drawdown of 40 m. The first earth fissure at Guangming Village was observed in 1998. The earth fissures, which developed in a zone characterized by a cumulative land subsidence of approximately 800 mm, are located at the flank of a main subsidence bowl with differential subsidence ranging from 0 to 1600 mm in 2001. The maximum differential subsidence rate amounts to 5 mm yr−1 between the two sides of the fissures. The fissure openings range from 30 to 80 mm, with a cumulative length of 1000 m. Depth of bed rock changes from 60 to 140 m across the earth fissure. The causes of earth fissure generation at Guangming Village includes a decrease in groundwater levels, differences in the thickness of aquifer system, shallow depths of bedrock ridges and cliffs, and subsequent differential land subsidence.

scholarly journals A probabilistic method for mapping earth fissure hazards

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mingdong Zang ◽  
Jianbing Peng ◽  
Nengxiong Xu ◽  
Zhijie Jia
Keyword(s):  
Factor Model ◽  
Probabilistic Method ◽  
Active Faults ◽  
Area Under The Curve ◽  
Susceptibility Map ◽  
Infrastructure Development ◽  
Mapping Procedure ◽  
Earth Fissure ◽  
Earth Fissures ◽  
Taiyuan Basin

AbstractEarth fissures caused by tectonic forces, human activities, or both seriously threaten the safety of people’s lives and properties. The Taiyuan Basin, a Cenozoic downfaulted basin located in the centre of the Fen-Wei Basin tectonic belt, in northwestern China, presents the ideal study area for a hazard assessment of earth fissures. A total of 104 earth fissures have been observed in the Taiyuan Basin, with a total length of approximately 128 km. In this paper, we proposed a probabilistic method for mapping earth fissure hazards by integrating the analytic hierarchy process (AHP), the area under the curve (AUC), and the certainty factor model (CFM). Geomorphic units, geologic formations, active faults and land subsidence zones of the Taiyuan Basin were mapped in detail. Correlations between these factors and earth fissures were evaluated through spatial modelling in ArcGIS. The AUC was introduced into the AHP to weight each factor and thus, to derive an earth fissure susceptibility map. Finally, the modelled earth fissure susceptibility was compared with a digital inventory of earth fissures to develop a probability function and map the spatial variability in failure probability through the CFM. The study indicates that active faults have the greatest contribution to the generation of earth fissures. Earth fissures are prone to develop in the piedmont alluvial-diluvial clinoplain and the transitional zone near the geomorphic boundary. This mapping procedure can assist in making rational decisions regarding urban planning and infrastructure development in areas susceptible to earth fissures.

Intracellular Dynamic Response Characteristics of Pineal Photoreceptors

1984 ◽  
Vol 16 (1-2) ◽  
pp. 119-122
Author(s):  
Y. Morit ◽  
K. Segi ◽  
M. Samejima ◽  
T. Nakamura
Keyword(s):  
Dynamic Response ◽  
Response Characteristics ◽  
Dynamic Response Characteristics ◽  
Pineal Photoreceptors ◽  
Intracellular Dynamic

Dynamic response characteristics of the plynlimon catchments and preliminary analysis of relationships to physical descriptors

1995 ◽  
Vol 6 (5) ◽  
pp. 465-472 ◽  
Author(s):  
C. E. M. Sefton ◽  
P. G. Whitehead ◽  
A. Eatherall ◽  
I. G. Littlewood ◽  
A. J. Jakeman
Keyword(s):  
Dynamic Response ◽  
Preliminary Analysis ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

Are the dynamic response characteristics of brachial artery flow-mediated dilation sensitive to the magnitude of increase in shear stimulus?

2008 ◽  
Vol 105 (1) ◽  
pp. 282-292 ◽  
Author(s):  
K. E. Pyke ◽  
J. A. Hartnett ◽  
M. E. Tschakovsky
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Dynamic Response ◽  
Phase I ◽  
Brachial Artery ◽  
Flow Mediated Dilation ◽  
Final Phase ◽  
Stimulus Magnitude ◽  
Brachial Artery Diameter ◽  
Response Characteristics

The purpose of this study was to determine the dynamic characteristics of brachial artery dilation in response to step increases in shear stress [flow-mediated dilation (FMD)]. Brachial artery diameter (BAD) and mean blood velocity (MBV) (Doppler ultrasound) were obtained in 15 healthy subjects. Step increases in MBV at two shear stimulus magnitudes were investigated: large (L; maximal MBV attainable), and small (S; MBV at 50% of the large step). Increase in shear rate (estimate of shear stress: MBV/BAD) was 76.8 ± 15.6 s−1 for L and 41.4 ± 8.7 s−1 for S. The peak %FMD was 14.5 ± 3.8% for L and 5.7 ± 2.1% for S ( P < 0.001). Both the L (all subjects) and the S step trials (12 of 15 subjects) elicited a biphasic diameter response with a fast initial phase (phase I) followed by a slower final phase. Relative contribution of phase I to total FMD when two phases occurred was not sensitive to shear rate magnitude ( r2 = 0.003, slope P = 0.775). Parameters quantifying the dynamics of the FMD response [time delay (TD), time constant (τ)] were also not sensitive to shear rate magnitude for both phases (phase I: TD r2 = 0.03, slope P = 0.376, τ r2 = 0.04, slope P = 0.261; final phase: TD r2 = 0.07, slope P = 0.169, τ r2 = 0.07, slope P = 0.996). These data support the existence of two distinct mechanisms, or sets of mechanisms, in the human conduit artery FMD response that are proportionally sensitive to shear stimulus magnitude and whose dynamic response is not sensitive to shear stimulus magnitude.

Dynamics Analysis of Refrigeration Compressor Based on Finite Element and Experimental Modes

2012 ◽  
Vol 499 ◽  
pp. 238-242
Author(s):  
Li Zhang ◽  
Hong Wu ◽  
Yan Jue Gong ◽  
Shuo Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Natural Frequency ◽  
High Precision ◽  
3D Model ◽  
Finite Element Models ◽  
Dynamics Analysis ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

Based on the 3D model of refrigeration's compressor by Pro/E software, the analyses of theoretical and experimental mode are carried out in this paper. The results show that the finite element models of compressor have high precision dynamic response characteristics and the natural frequency of the compressor, based on experimental modal analysis, can be accurately obtained, which will contribute to further dynamic designs of mechanical structures.

scholarly journals Research on the Shock Response Characteristics of a Threaded Connection Using the Thin-Layer Element Method

2021 ◽  
Vol 11 (12) ◽  
pp. 5611
Author(s):  
A’min Yan ◽  
Xiaofeng Wang ◽  
He Yang ◽  
Fenglei Huang ◽  
Aiguo Pi
Keyword(s):  
Dynamic Response ◽  
Thin Layer ◽  
Contact Stiffness ◽  
Maximum Error ◽  
Elastic Model ◽  
Material Parameters ◽  
Response Characteristics ◽  
Threaded Connection ◽  
Constraint Method ◽  
Element Method

Nonlinear factors such as the contact stiffness and friction damping at the threaded interface of a projectile–fuse system significantly affect the dynamic response characteristics. To obtain the dynamic response of the fuse body accurately during penetration, it is necessary to characterize these nonlinear factors reasonably. Because the existing structural dynamics software cannot effectively deal with nonlinear factors, the thin-layer element method was used to represent the nonlinear factors in this study. By combining the thread elastic model with thin-layer element principles, an effective method for determining the material parameters of the thin-layer element was established theoretically, which provided a different method of determining material parameters, not just relying on experiments. The accuracy of the material parameters was verified based on modal experiments with threaded tubes having different specifications. The errors were within 5%, indicating the reliability of the theoretical determination method for the material parameters. In addition, projectile penetration into a semi-infinite concrete target was tested to verify the accuracy of the thin-layer element modeling. Compared with the ‘TIED’ constraint method, the resonant frequency obtained with the thin-layer element method was in better agreement with that of the experimental data. The maximum error decreased from 15.7 to 7.8%, indicating that the thin-layer element method could accurately represent the nonlinear factors. Thus, this study serves as a reference for accurately evaluating the dynamic response of the fuse body of a penetrator.

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