scholarly journals Deformation Activity Analysis of a Ground Fissure Based on Instantaneous Total Energy

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2607
Author(s):  
Xianglei Liu ◽  
Shan Su ◽  
Jing Ma ◽  
Wanxin Yang
Keyword(s):  
Time Series ◽  
Total Energy ◽  
Hanging Wall ◽  
Vertical Direction ◽  
Activity Analysis ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Mode Decomposition ◽  
Original Time ◽  
Beijing China

This study proposes a novel instantaneous total energy method to perform an activity analysis of ground fissures deformation, which is calculated by integrating the extreme-point symmetric mode decomposition (ESMD) method and kinetic energy based on the time-series displacement acquired by shape acceleration array (SAA) sensors. The proposed method is tested on the Xiwang Road fissure in Beijing, China. First, to fully monitor the hanging wall and footwall of the monitored ground fissure, a 4 m-long SAA in the vertical direction and an 8 m-long SAA in the horizontal direction were embedded in a ground fissure to obtain an accurate time-series displacement with an accuracy of ±1.5 mm/32 m and a displacement acquisition frequency of once an hour. Second, to improve the accuracy of the activity analysis, the ESMD method and Spearman’s rho are applied to perform signal denoising of the original time-series displacement obtained by the SAA sensors. Finally, the instantaneous total energy is obtained to analyze the activity of the monitored ground fissure. The results demonstrate that the proposed method is more reliable to reflect the activity of a monitored ground fissure compared to the time-series displacement.

scholarly journals Activity Characteristics and Safety distance of Gaoliying Ground Fissure in Beijing

2019 ◽  
Vol 79 ◽  
pp. 02009
Author(s):  
Haigang Wang ◽  
Tongchun Qin ◽  
Haipeng Guo ◽  
Juyan Zhu ◽  
Yunlong Wang ◽  
...  
Keyword(s):  
Ground Water ◽  
Land Subsidence ◽  
Groundwater Level ◽  
Hanging Wall ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Rapid Decrease ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Safety Distance

In all ground fissures in Beijing, Gaoliying Ground Fissure has characteristics of highly activity, and it cause serious damages on constructoins. With the distribution as well as the development of land subsidence and the change of the groundwater level, a series of work has been conducted to explain the mechanism of the formation of Gaoliying Ground Fissure. For example, field damage investigations and trench observations were used to define the affected distance of ground fissure; three-dimensional deformation was monitored to determine active characteristic of ground fissure. This paper points out that Gaoliying ground fissure is controlled by Huangzhuang-Gaoliying Fault, which mainly moves in the vertical direction. The rapid decrease of the ground water level greatly increases the development of ground fissure. The distance of damaged zones affected by ground fissure in the hanging-wall of the fault reaches 49.5m, and the distance of damaged zones in the footwall of the fault is 17.5 m. A suggested safety distance of type-one and type-two buildings is 100 m. For type-three buildings, the suggested safety distance is 80 m.

scholarly journals Land Subsidence and Ground Fissures in Beijing Capital International Airport (BCIA): Evidence from Quasi-PS InSAR Analysis

2019 ◽  
Vol 11 (12) ◽  
pp. 1466 ◽  
Author(s):  
Mingliang Gao ◽  
Huili Gong ◽  
Xiaojuan Li ◽  
Beibei Chen ◽  
Chaofan Zhou ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Land Subsidence ◽  
Deformation Rate ◽  
Normal Operation ◽  
Integrated Analysis ◽  
Ground Fissure ◽  
Ground Fissures ◽  
International Airport ◽  
Series Analysis

Land subsidence is a global environmental geological hazard caused by natural or human activities. The high spatial resolution and continuous time coverage of interferometric synthetic aperture radar (InSAR) time series analysis techniques provide data and a basis for the development of methods for the investigation and evolution mechanism study of regional land subsidence. Beijing, the capital city of China, has suffered from land subsidence for decades since it was first recorded in the 1950s. It was reported that uneven ground subsidence and fractures have seriously affected the normal operation of the Beijing Capital International Airport (BCIA) in recent years before the overhaul of the middle runway in April 2017. In this study, InSAR time series analysis was successfully used to detect the uneven local subsidence and ground fissure activity that has been gradually increasing in BCIA since 2010. A multi-temporal InSAR (MT-InSAR) technique was performed on 63 TerraSAR-X/TanDem-X (TSX/TDX) images acquired between 2010 and 2017, then deformation rate maps and time series for the airport area were generated. Comparisons of deformation rate and displacement time series from InSAR and ground-leveling were carried out in order to evaluate the accuracy of the InSAR-derived measurements. After an integrated analysis of the distribution characteristics of land subsidence, previous research results, and geological data was carried out, we found and located an active ground fissure. Then main cause of the ground fissures was preliminarily discussed. Finally, it can be conducted that InSAR technology can be used to identify and monitor geological processes, such as land subsidence and ground fissure activities, and can provide a scientific approach to better explore and study the cause and formation mechanism of regional subsidence and ground fissures.

scholarly journals MONITORING OF THE GROUND FISSURE ACTIVITY WITHIN YUNCHENG BASIN BY TIME SERIES INSAR

2018 ◽  
Vol XLII-3 ◽  
pp. 2251-2255 ◽  
Author(s):  
F. Zhang ◽  
C. S. Yang ◽  
C. Y. Zhao ◽  
R. C. Liu
Keyword(s):  
Time Series ◽  
Ground Deformation ◽  
Active Faults ◽  
Ground Subsidence ◽  
Surrounding Area ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Surrounding Environment ◽  
Yuncheng Basin ◽  
X Band

Yuncheng area is one of the most extensive distributions of ground fissures in Shanxi basin, especially in Yanhu District of Yuncheng, the disaster of ground fissures and ground subsidence are the most serious. According to previous studies, the development and distribution of the ground fissures in this area are mainly controlled by the underlying active faults. In order to provide a better understanding of the formation mechanism, the deformation of ground fissures and its surrounding environment should be taken into consideration. In this paper, PS-InSAR technology was employed to assess the time-series ground deformation of Yuncheng ground fissures and its surrounding area with X-band TerraSAR images from 2013 to 2015. The interaction between ground fissures activity and land subsidence, groundwater, precipitation and surrounding faults will be discussed.

Study on Interaction between Soil and U-Shaped Subway Tunnel in the Environment of Ground Fissures

2011 ◽  
Vol 250-253 ◽  
pp. 2342-2345 ◽  
Author(s):  
Yang Liu ◽  
Kai Ling Li ◽  
Yu Ming Men ◽  
Guang Yuan Weng ◽  
Hong Jia Liu
Keyword(s):  
Hanging Wall ◽  
Interaction Mechanism ◽  
Vertical Displacement ◽  
Soil Mass ◽  
Relative Displacement ◽  
Tunnel Structure ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Deformation Area

The interaction mechanism, between soil and U-shaped Subway tunnel, is studied by numerical simulation in the environment of ground fissures. The Subway Line 2 through the ground fissures in Xi’an. The analysis results show that the soil mass influenced by the relative displacement and the vertical displacement gradually increases with the relative displacement increasing of ground fissures movement. The deformation area of tunnel lies in the two sides of presupposed ground fissure, and the area enlarge with vertical relative displacement increasing. The tunnel structure damages at the ground fissures when the relative displacement reaches to 100mm. The footwall part is in tension and the hanging wall part is under pressure on the top of tunnel structure at the ground fissure. The footwall part is under pressure and the hanging wall part is in tension on the bottom of tunnel structure at the ground fissure. In the practical projects, the sectional type tunnel should be employed when the Subway tunnel through the ground fissures.

An Integrated Model Combined ARIMA, EMD with SVR for Stock Indices Forecasting

2016 ◽  
Vol 25 (02) ◽  
pp. 1650005 ◽  
Author(s):  
Heng-Li Yang ◽  
Han-Chou Lin
Keyword(s):  
Time Series ◽  
Financial Time Series ◽  
Linear Part ◽  
Time Series Forecasting ◽  
Support Vector ◽  
Nonlinear Part ◽  
Financial Time ◽  
Stock Indices ◽  
Mode Decomposition ◽  
Original Time

Financial time series forecasting has become a challenge because it is noisy, non-stationary and chaotic. To overcome this limitation, this paper uses empirical mode decomposition (EMD) to aid the financial time series forecasting and proposes an approach via combining ARIMA and SVR (Support Vector Regression) to forecast. The approach contains four steps: (1) using ARIMA to analyze the linear part of the original time series; (2) EMD is used to decompose the dynamics of the non-linear part into several intrinsic mode function (IMF) components and one residual component; (3) developing a SVR model using the above IMFs and residual components as inputs to model the nonlinear part; (4) combining the forecasting results of linear model and nonlinear model. To verify the effectiveness of the proposed approach, four stock indices are chosen as the forecasting targets. Comparing with some existing state-of-the-art models, the proposed approach gives superior results.

scholarly journals An Improved Adaptive IVMD-WPT-Based Noise Reduction Algorithm on GPS Height Time Series

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8295
Author(s):  
Huaqing Xu ◽  
Tieding Lu ◽  
Jean-Philippe Montillet ◽  
Xiaoxing He
Keyword(s):  
Time Series ◽  
Objective Function ◽  
Noise Reduction ◽  
Signal To Noise Ratio ◽  
Wavelet Packet ◽  
Variational Mode Decomposition ◽  
Mode Decomposition ◽  
Penalty Factor ◽  
Reduction Effect ◽  
Original Time

To improve the reliability of Global Positioning System (GPS) signal extraction, the traditional variational mode decomposition (VMD) method cannot determine the number of intrinsic modal functions or the value of the penalty factor in the process of noise reduction, which leads to inadequate or over-decomposition in time series analysis and will cause problems. Therefore, in this paper, a new approach using improved variational mode decomposition and wavelet packet transform (IVMD-WPT) was proposed, which takes the energy entropy mutual information as the objective function and uses the grasshopper optimisation algorithm to optimise the objective function to adaptively determine the number of modal decompositions and the value of the penalty factor to verify the validity of the IVMD-WPT algorithm. We performed a test experiment with two groups of simulation time series and three indicators: root mean square error (RMSE), correlation coefficient (CC) and signal-to-noise ratio (SNR). These indicators were used to evaluate the noise reduction effect. The simulation results showed that IVMD-WPT was better than the traditional empirical mode decomposition and improved variational mode decomposition (IVMD) methods and that the RMSE decreased by 0.084 and 0.0715 mm; CC and SNR increased by 0.0005 and 0.0004 dB, and 862.28 and 6.17 dB, respectively. The simulation experiments verify the effectiveness of the proposed algorithm. Finally, we performed an analysis with 100 real GPS height time series from the Crustal Movement Observation Network of China (CMONOC). The results showed that the RMSE decreased by 11.4648 and 6.7322 mm, and CC and SNR increased by 0.1458 and 0.0588 dB, and 32.6773 and 26.3918 dB, respectively. In summary, the IVMD-WPT algorithm can adaptively determine the number of decomposition modal functions of VMD and the optimal combination of penalty factors; it helps to further extract effective information for noise and can perfectly retain useful information in the original time series.

scholarly journals Adaptive complementary ensemble EMD and energy-frequency spectra of cryptocurrency prices

2021 ◽  
pp. 2141008
Author(s):  
Tim Leung ◽  
Theodore Zhao
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Ensemble Empirical Mode Decomposition ◽  
Intrinsic Mode Functions ◽  
Original Time Series ◽  
Frequency Spectra ◽  
Mode Decomposition ◽  
Original Time ◽  
Instantaneous Frequencies ◽  
Instantaneous Energy

In this study, we study the price dynamics of cryptocurrencies using adaptive complementary ensemble empirical mode decomposition (ACE-EMD) and Hilbert spectral analysis. This is a multiscale noise-assisted approach that decomposes any time series into a number of intrinsic mode functions, along with the corresponding instantaneous amplitudes and instantaneous frequencies. The decomposition is adaptive to the time-varying volatility of each cryptocurrency price evolution. Different combinations of modes allow us to reconstruct the time series using components of different timescales. We then apply Hilbert spectral analysis to define and compute the instantaneous energy-frequency spectrum of each cryptocurrency to illustrate the properties of various timescales embedded in the original time series.

Model Test of the Impact of Active Ground Fissures on Metro Tunnel

2013 ◽  
Vol 405-408 ◽  
pp. 1334-1339
Author(s):  
Yi Yuan ◽  
Qiang Bing Huang ◽  
Jie Han ◽  
Ming Li Li
Keyword(s):  
Model Test ◽  
Hanging Wall ◽  
Foot Wall ◽  
Test Results ◽  
Soil Pressure ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Tunnel Diameter ◽  
Metro Tunnel ◽  
The Impact

A model test was performed to investigate the impact of active ground fissure on metro tunnel. The test results show that under the action of active ground fissure, the metro tunnel behaviors as a cantilever elastic foundation beam, and the top is in tension and its bottom is in compression. The tensile parts are located in the foot-wall with the range 0.75～2.33D（D is tunnel diameter） distance from active ground fissure and the compressive parts are mainly located in the foot-wall with the range 3D distance from the fissure. When the settlement of hanging wall of ground fissure reaches 1cm（25cm in prototype）, the tunnel bottom appear cavity in the hanging wall and cracks in the foot-wall. With the settlement development of the hanging wall of active ground fissure the vertical soil pressure on the top of tunnel greatly increases and reduces at the bottom of tunnel in the hanging wall.

scholarly journals Superiority of Hybrid Soft Computing Models in Daily Suspended Sediment Estimation in Highly Dynamic Rivers

2021 ◽  
Vol 13 (2) ◽  
pp. 542
Author(s):  
Tarate Suryakant Bajirao ◽  
Pravendra Kumar ◽  
Manish Kumar ◽  
Ahmed Elbeltagi ◽  
Alban Kuriqi
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Suspended Sediment ◽  
River Basin ◽  
Time Series Data ◽  
Series Data ◽  
Discrete Wavelet ◽  
Original Time Series ◽  
Inference System ◽  
Original Time

Estimating sediment flow rate from a drainage area plays an essential role in better watershed planning and management. In this study, the validity of simple and wavelet-coupled Artificial Intelligence (AI) models was analyzed for daily Suspended Sediment (SSC) estimation of highly dynamic Koyna River basin of India. Simple AI models such as the Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) were developed by supplying the original time series data as an input without pre-processing through a Wavelet (W) transform. The hybrid wavelet-coupled W-ANN and W-ANFIS models were developed by supplying the decomposed time series sub-signals using Discrete Wavelet Transform (DWT). In total, three mother wavelets, namely Haar, Daubechies, and Coiflets were employed to decompose original time series data into different multi-frequency sub-signals at an appropriate decomposition level. Quantitative and qualitative performance evaluation criteria were used to select the best model for daily SSC estimation. The reliability of the developed models was also assessed using uncertainty analysis. Finally, it was revealed that the data pre-processing using wavelet transform improves the model’s predictive efficiency and reliability significantly. In this study, it was observed that the performance of the Coiflet wavelet-coupled ANFIS model is superior to other models and can be applied for daily SSC estimation of the highly dynamic rivers. As per sensitivity analysis, previous one-day SSC (St-1) is the most crucial input variable for daily SSC estimation of the Koyna River basin.

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