Experimental study of the particle agglomeration on its mechanical properties of collapsible loess

Loess, distributed all over the world, exhibits the behavior that is related to their formation history, mineralogy, and microstructure, which can cause serious geotechnical engineering problems. This paper presents the Baozhong railway is a key transportation channel for Guyuan city in Ningxia prov...

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Main Authors: Meng Zhao, Hong-Gang Wu, Wei Guo, Bo-Ren Tan, Cheng Hu, Rui Deng, Li-Yi Chen
Format: Article
Language:English
Published: Frontiers Media S.A. 2022-09-01
Series:Frontiers in Earth Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/feart.2022.943383/full
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author Meng Zhao
Meng Zhao
Hong-Gang Wu
Wei Guo
Bo-Ren Tan
Cheng Hu
Rui Deng
Li-Yi Chen
author_facet Meng Zhao
Meng Zhao
Hong-Gang Wu
Wei Guo
Bo-Ren Tan
Cheng Hu
Rui Deng
Li-Yi Chen
author_sort Meng Zhao
collection DOAJ
description Loess, distributed all over the world, exhibits the behavior that is related to their formation history, mineralogy, and microstructure, which can cause serious geotechnical engineering problems. This paper presents the Baozhong railway is a key transportation channel for Guyuan city in Ningxia province of northwestern China. Based on field investigations treasure middle section of the railway in the study area, it is found that the more serious diseases subgrade settlement, local roads embankment platform dislocation occurs and lots of cracks were founded. For several years, with the train speed increasing, and due to the influence of widespread flood irrigation on the farmland, the subgrade experienced a degree of settlement. This settlement was not alleviated after three treatments, which seriously affected train safety. In order to analyze the reason for the railway line settlement, soil samples were collected from the collapsible loess subgrade. Consolidation test, particle size analysis test, X-ray diffraction test (XRD), and scanning electron microscopy test (SEM) were performed to investigate the mechanism of the subgrade disease. The results reveal that loess collected from severe differential settlements at locations has a highly compressible, and its clay content and agglomeration level was generally low. These results illustrated that the particle size of 20–50 microns has a direct effect on its mechanical properties of loess. This part of the particles has a cementation effect. It can effectively connect the large particles of the skeleton to form particle agglomerates and is an effective composition of loess clay minerals. Therefore, the loess structure was not stable due to its relatively low internal molecular attraction. When such saturated collapsible loess subgrade subjected to train vibration load, the soil might be liquefied, and its structure might be instable. If the drainage of the subgrade was not well designed, severe differential settlements would occur. The research is of great significance to clarify the relationship between loess particle composition, microstructure and its macromechanics, providing a vital reference for the engineering construction in the loess-dominated areas.
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spelling doaj.art-0731a0a165a542619e4c81bf4468fecf2022-12-22T04:26:11ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-09-011010.3389/feart.2022.943383943383Experimental study of the particle agglomeration on its mechanical properties of collapsible loessMeng Zhao0Meng Zhao1Hong-Gang Wu2Wei Guo3Bo-Ren Tan4Cheng Hu5Rui Deng6Li-Yi Chen7Sichuan Engineering Research Center for Mechanical Properties and Engineering Technology of Unsaturated Soils, Chengdu University, Chengdu, ChinaState Key Laboratory of Geo-Hazard Prevention and Geo-Protection, Chengdu University of Technology, Chengdu, ChinaChina Northwest Research Institute Co., Ltd of CREC, Lanzhou, ChinaState Key Laboratory of Geo-Hazard Prevention and Geo-Protection, Chengdu University of Technology, Chengdu, ChinaSichuan Engineering Research Center for Mechanical Properties and Engineering Technology of Unsaturated Soils, Chengdu University, Chengdu, ChinaSichuan Engineering Research Center for Mechanical Properties and Engineering Technology of Unsaturated Soils, Chengdu University, Chengdu, ChinaSichuan Engineering Research Center for Mechanical Properties and Engineering Technology of Unsaturated Soils, Chengdu University, Chengdu, ChinaState Key Laboratory of Geo-Hazard Prevention and Geo-Protection, Chengdu University of Technology, Chengdu, ChinaLoess, distributed all over the world, exhibits the behavior that is related to their formation history, mineralogy, and microstructure, which can cause serious geotechnical engineering problems. This paper presents the Baozhong railway is a key transportation channel for Guyuan city in Ningxia province of northwestern China. Based on field investigations treasure middle section of the railway in the study area, it is found that the more serious diseases subgrade settlement, local roads embankment platform dislocation occurs and lots of cracks were founded. For several years, with the train speed increasing, and due to the influence of widespread flood irrigation on the farmland, the subgrade experienced a degree of settlement. This settlement was not alleviated after three treatments, which seriously affected train safety. In order to analyze the reason for the railway line settlement, soil samples were collected from the collapsible loess subgrade. Consolidation test, particle size analysis test, X-ray diffraction test (XRD), and scanning electron microscopy test (SEM) were performed to investigate the mechanism of the subgrade disease. The results reveal that loess collected from severe differential settlements at locations has a highly compressible, and its clay content and agglomeration level was generally low. These results illustrated that the particle size of 20–50 microns has a direct effect on its mechanical properties of loess. This part of the particles has a cementation effect. It can effectively connect the large particles of the skeleton to form particle agglomerates and is an effective composition of loess clay minerals. Therefore, the loess structure was not stable due to its relatively low internal molecular attraction. When such saturated collapsible loess subgrade subjected to train vibration load, the soil might be liquefied, and its structure might be instable. If the drainage of the subgrade was not well designed, severe differential settlements would occur. The research is of great significance to clarify the relationship between loess particle composition, microstructure and its macromechanics, providing a vital reference for the engineering construction in the loess-dominated areas.https://www.frontiersin.org/articles/10.3389/feart.2022.943383/fullparticle agglomerationmechanical propertiesexisting railway linecollapsible loessexperimental study
spellingShingle Meng Zhao
Meng Zhao
Hong-Gang Wu
Wei Guo
Bo-Ren Tan
Cheng Hu
Rui Deng
Li-Yi Chen
Experimental study of the particle agglomeration on its mechanical properties of collapsible loess
Frontiers in Earth Science
particle agglomeration
mechanical properties
existing railway line
collapsible loess
experimental study
title Experimental study of the particle agglomeration on its mechanical properties of collapsible loess
title_full Experimental study of the particle agglomeration on its mechanical properties of collapsible loess
title_fullStr Experimental study of the particle agglomeration on its mechanical properties of collapsible loess
title_full_unstemmed Experimental study of the particle agglomeration on its mechanical properties of collapsible loess
title_short Experimental study of the particle agglomeration on its mechanical properties of collapsible loess
title_sort experimental study of the particle agglomeration on its mechanical properties of collapsible loess
topic particle agglomeration
mechanical properties
existing railway line
collapsible loess
experimental study
url https://www.frontiersin.org/articles/10.3389/feart.2022.943383/full
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