Analysis of Calculated Subgrade Settlement in the Loess Area

2021 ◽  
pp. 120-129
Author(s):  
Li Jianwei ◽  
Guo Shubo ◽  
Huang Defu ◽  
Hou Jue ◽  
Yao Jun ◽  
...  
Keyword(s):  
Loess Area

scholarly journals Optimization Analysis of Settlement Parameters for Postgrouting Piles in Loess Area of Shaanxi, China

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Zhijun Zhou ◽  
Shanshan Zhu ◽  
Xiang Kong ◽  
Jiangtao Lei ◽  
Tong Liu
Keyword(s):  
Compression Modulus ◽  
Summation Method ◽  
Cone Penetration ◽  
Optimization Analysis ◽  
Loess Area ◽  
Elastic Compression ◽  
Settlement Calculation ◽  
Side Resistance ◽  
Load Tests ◽  
The Relationship

The settlement calculation of postgrouting piles is complex and depends on the calculation method and parameters. Static load tests were conducted to compare the settlement characteristics of nongrouting and postgrouting piles, and three vital parameters in the layer-wise summation method were revised to predict the settlement of postgrouting piles. The elastic compression coefficient was deduced based on the Mindlin–Geddes method by considering the influence of the change in the pile side resistance distribution and end resistance ratio on the elastic compression after grouting. The relationship between the compression modulus and soil gravity stress and cone penetration resistance were established, respectively, using experimental data. The optimum value of the settlement empirical coefficient was determined using regional data. Finally, we used the postgrouting pile of the Wuqi–Dingbian expressway as a practical example. The results obtained from the layer-wise summation method after parametric optimization were close to the measured values. The results of this study provide reference data and guidance for the settlement calculation of postgrouting piles in this area.

MILL: Channel Attention–based Deep Multiple Instance Learning for Landslide Recognition

2021 ◽  
Vol 17 (2s) ◽  
pp. 1-11
Author(s):  
Xiaochuan Tang ◽  
Mingzhe Liu ◽  
Hao Zhong ◽  
Yuanzhen Ju ◽  
Weile Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Remote Sensing ◽  
Large Scale ◽  
Remote Sensing Image ◽  
Disaster Risk ◽  
Multiple Instance Learning ◽  
Remote Sensing Images ◽  
Loess Area ◽  
Remote Sensing Image Classification ◽  
Natural Disaster Risk

Landslide recognition is widely used in natural disaster risk management. Traditional landslide recognition is mainly conducted by geologists, which is accurate but inefficient. This article introduces multiple instance learning (MIL) to perform automatic landslide recognition. An end-to-end deep convolutional neural network is proposed, referred to as Multiple Instance Learning–based Landslide classification (MILL). First, MILL uses a large-scale remote sensing image classification dataset to build pre-train networks for landslide feature extraction. Second, MILL extracts instances and assign instance labels without pixel-level annotations. Third, MILL uses a new channel attention–based MIL pooling function to map instance-level labels to bag-level label. We apply MIL to detect landslides in a loess area. Experimental results demonstrate that MILL is effective in identifying landslides in remote sensing images.

scholarly journals Subsidence Monitoring of Fill Area in Yan’an New District Based on Sentinel-1A Time Series Imagery

2021 ◽  
Vol 13 (15) ◽  
pp. 3044
Author(s):  
Mingjie Liao ◽  
Rui Zhang ◽  
Jichao Lv ◽  
Bin Yu ◽  
Jiatai Pang ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Ground Deformation ◽  
Dynamic Change ◽  
Deformation Monitoring ◽  
Chinese Loess Plateau ◽  
Ground Subsidence ◽  
Shanxi Province ◽  
Environment Change ◽  
Loess Area

In recent years, many cities in the Chinese loess plateau (especially in Shanxi province) have encountered ground subsidence problems due to the construction of underground projects and the exploitation of underground resources. With the completion of the world’s largest geotechnical project, called “mountain excavation and city construction,” in a collapsible loess area, the Yan’an city also appeared to have uneven ground subsidence. To obtain the spatial distribution characteristics and the time-series evolution trend of the subsidence, we selected Yan’an New District (YAND) as the specific study area and presented an improved time-series InSAR (TS-InSAR) method for experimental research. Based on 89 Sentinel-1A images collected between December 2017 to December 2020, we conducted comprehensive research and analysis on the spatial and temporal evolution of surface subsidence in YAND. The monitoring results showed that the YAND is relatively stable in general, with deformation rates mainly in the range of −10 to 10 mm/yr. However, three significant subsidence funnels existed in the fill area, with a maximum subsidence rate of 100 mm/yr. From 2017 to 2020, the subsidence funnels enlarged, and their subsidence rates accelerated. Further analysis proved that the main factors induced the severe ground subsidence in the study area, including the compressibility and collapsibility of loess, rapid urban construction, geological environment change, traffic circulation load, and dynamic change of groundwater. The experimental results indicated that the improved TS-InSAR method is adaptive to monitoring uneven subsidence of deep loess area. Moreover, related data and information would provide reference to the large-scale ground deformation monitoring and in similar loess areas.

Charcoals from three Neolithic settlements in the loess area of south-central Poland

1992 ◽  
Vol 139 (2-4) ◽  
pp. 373-382 ◽  
Author(s):  
Krystyna Wasylikowa ◽  
Irena Gluza ◽  
Maria Litynska-Zajac ◽  
Zofia Tomczynska
Keyword(s):  
Loess Area ◽  
Central Poland ◽  
South Central

Loess Highway Tunnel Construction Process of Three Dimensional Numerical Simulation

2012 ◽  
Vol 256-259 ◽  
pp. 1276-1279
Author(s):  
Bai Liu ◽  
Bin Zhang ◽  
Jing Kong ◽  
Jian Pang
Keyword(s):  
Three Dimensional ◽  
Shanxi Province ◽  
Tunnel Construction ◽  
Western Region ◽  
High Grade ◽  
Construction Process ◽  
Construction Technique ◽  
Loess Area ◽  
Highway Tunnel ◽  
Deformation Law

In recent years, as China's national sustained and rapid economic development, the state increased investment to middle-western region, promote the regional development of high grade highway. Therefore, highway tunnel through loess area is getting more and more. Due to the special physical properties of loess, it makes the loess tunnel construction a hot topic. To study on the deformation law of the loess highway tunnel, this paper based on the Shanxi Province Guang Ling to Hun Yuan highway tunnel—East Fu Yao tunnel, we simulate the whole section pre-reinforcement construction technique for three dimensional numerical, and combined with field monitoring measurement to compare and analyze in paper

Reconsidering the paleoclimate implications of magnetic susceptibility records of Holocene loessic soils

2021 ◽  
Author(s):  
Diana Jordanova ◽  
Neli Jordanova
Keyword(s):  
Magnetic Susceptibility ◽  
Parent Material ◽  
Chinese Loess Plateau ◽  
Absolute Difference ◽  
Physical Parameters ◽  
Soil Profiles ◽  
Chinese Loess ◽  
Loess Area ◽  
River Terraces ◽  
Paleoclimate Proxy

<p>Mass specific magnetic susceptibility variations with depth along soil profiles developed on loess parent material is one of the most frequently used physical parameters in local, regional and global correlations of loess deposits. It is also utilized as a paleo-precipitation proxy, defined either as absolute difference between susceptibilities of the enhanced B-horizon and parent loess, or as relative enhancement using ratios of magnetic parameters. These different approaches in the application of magnetic susceptibility as paleoclimate proxy lead us to perform a comparative study on a number of Holocene soil profiles developed on loess from European loess area and the Chinese Loess Plateau (CLP). We made a compilation of data including 20 profiles from North Bulgaria, 28 profiles from Eastern and Central Europe; and 26 profiles from the CLP. Minimum magnetic susceptibilities of the last glacial loess (X<sub>min</sub>) from the compiled data base for European and Chinese profiles show climate related variability, revealing multi linear relationship with both present day MAP and MAT values for the corresponding locations. Strong deviations of X<sub>min</sub> from this dependence display sites located at low elevation river terraces, Black sea coast and possessing large content of coarse silt and sand fractions. Pedogenic magnetic susceptibility (X<sub>pedo</sub>) defined as (X<sub>max</sub> - X<sub>min</sub>) with  X<sub>max</sub> determined from the youngest part (last 1500 – 2000 years B.P.) of the Holocene magnetic susceptibility records of Chinese sections and absolute X<sub>max</sub> of the European sites show systematic dependence on modern MAP and MAT values. This dependence is uniform for all sites with steppe vegetation, while higher scatter and steeper regression trends are observed for sites under mixed (steppe – forest) and forest vegetation. The study is financially supported by project No KP-06-N34/2 funded by the Bulgarian National Science Fund.</p>

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