Laboratory Experiments and Numerical Simulation Study of Composite-Material-Modified Loess Improving High-Speed Railway Subgrade

Luo, Li; Wang, Xingang; Xue, Chen; Wang, Daozheng; Lian, Baoqin

doi:10.3390/polym14153215

Cited by 13 publications

(9 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Large loess covers lie in China. Analyses including FEM calculations for the improved loess subsoil were presented in [71]. The subsoil was improved due to the collapsing nature of loess.…”

Section: Discussionmentioning

confidence: 99%

3D FEM Analysis of the Subsoil-Building Interaction

Nepelski

2022

Applied Sciences

View full text Add to dashboard Cite

This paper presents the process of advanced numerical analysis of interaction between a building and the subsoil. The analysis covered a wide range of work for both computing and research. As part of the research work, field and laboratory subsoil tests were carried out, as well as geodetic measurements of building settlement and measurements of natural vibrations of an object. The computational work included the analysis of a total of 47 FEM models. The subsoil was described using the Modified Cam-Clay model, with parameters determined using field CPT and SDMT tests, as well as triaxial and edometric laboratory tests. Parts with geodetic benchmarks were separated from the building model, and then multi-variant calculations were made on smaller, partial models with parameters obtained from various methods. Calibration of the main models was performed using 8 partial models for which calculations were carried out in 4–5 variants of parameters. This gave a total of 38 partial models. Then, calculations were carried out on the full model of the building with subsoil. At each stage, the results of vertical displacements were compared to the geodetic values. The measured settlement of the real building in the time from the construction of the underground story to its use for the period of 1 year, was from 2.3 mm to 7.8 mm. The settlement from FEM calculations of small calibration models for the same benchmarks was from 2.0 mm to 9.8 mm with parameters derived from CPT tests and from 1.8 to 7.3 mm for parameters derived from SDMT. For the full building model, settlement from FEM calculations ranged from 2.2 to 8.8 for the variant with a simplified subsoil model, and from 3.7 to 10.5 for the model taking into account the inhomogeneity of the subsoil. As a result, it was found that the displacements from the numerical analysis were convergent with the geodetic values. Detailed numerical analyses also allowed to detect the deviations of the segments from the vertical and to indicate potential damage to the structure. It was also indicated how the work of the subsoil influences the stress distribution in selected structural elements. Behaviour of the subsoil has an impact on the behaviour of the building and its deformations, as well as on the distribution of stresses in the structural elements, and, as a result, on the change in the distribution of internal forces in the structure.

show abstract

“…Large loess covers lie in China. Analyses including FEM calculations for the improved loess subsoil were presented in [71]. The subsoil was improved due to the collapsing nature of loess.…”

Section: Discussionmentioning

confidence: 99%

3D FEM Analysis of the Subsoil-Building Interaction

Nepelski

2022

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…to control the compactness and stability of subgrade filling. At the same time, polymers, geotextiles and geogrids can be added to the subgrade fill to reduce the differential settlement deformation of the transition section [13][14][15][16][17][18] . These methods can have a significant effect on the differential settlement control of bridge-subgrade transition sections in collapsible loess areas.…”

Section: And Weiwei Wumentioning

confidence: 99%

Long-term monitoring and analysis of the longitudinal differential settlement of an expressway bridge–subgrade transition section in a loess area

Chao

et al. 2022

Sci Rep

View full text Add to dashboard Cite

To solve the problem of "bridgehead bumping" in the transition section between the road and bridge of an expressway in a collapsible loess area, a lime–soil compaction pile composite foundation is used for the first time in the transition section between the road and bridge of an expressway in China; the loess subgrade is improved by adding lime, and the subgrade is arranged in a multilayer geogrid for the joint treatment of various engineering measures. At the same time, a new type of precision differential pressure settlement meter is used to monitor the long-term settlement of a bridge–subgrade transition section with a small settlement magnitude after the joint treatment, and the distribution characteristics and variation laws of the settlement along the longitudinal direction of the line are obtained. The results show that the effect is better and the differential settlement is smaller when using a lime–soil compaction pile composite foundation; lime improves the loess subgrade backfill, and the multilayer geogrid addresses the bridge–subgrade transition in the collapsible loess area. The differential settlement and settlement rate of the subgrade and abutment increase with increased monitoring time, and the differential settlement increases gradually, while the growth rate decreases gradually and finally tends to be stable. The differential settlement of the transition section is predicted and analysed by using a hyperbolic curve, exponential curve and their combination in a prediction model, and the prediction analysis shows that the combined prediction model has the best prediction effect. These research results can provide guidance and reference for the design and construction of subgrade structures similar to the wet transition section between roads and bridges.

show abstract

“…Bai et al 22 used a collapsibility test, gray relational analysis, and unconfined compressive strength test to study calcium lignosulfonate-modified loess's collapsibility and mechanical properties. Luo et al 23 conducted direct shear tests and unconfined compression tests by adding cement, polypropylene fibers, and loess samples of SCA-2 soil stabilizer composites and found that the compressive strength indexes of modified loess had a significant impact on foundation settlement. Cheng et al 24 proposed using microorganism-induced calcium carbonate deposition technology to modify loess mechanical performance.…”

Section: Introductionmentioning

confidence: 99%

Experimental study on basic engineering properties of loess improved by burnt rock

Chen¹,

Shao

Liu³

et al. 2023

Preprint

View full text Add to dashboard Cite

Engineering construction hazards and geological disasters in loess areas were severe due to the extraordinary nature of loess and its complex internal structure. However, burnt rock-solid waste was often used as filling material and light aggregate, while there were few studies on the engineering mechanical properties of modified soil. This paper proposed a method of burnt rock solid waste-modified loess. Therefore, we conducted compression-consolidation and direct shear tests on burnt rock solid waste-modified loess under different burnt rock contents to explore its improved loess’s deformation and strength characteristics. Then, we used an SEM to investigate the modified loess’s micro-structures under different burnt rock contents. The results showed that as the burnt rock-solid waste particle content continued to increase, the void ratio and compressibility coefficient of the samples with different ranges of burnt rock-solid waste particles gradually decreased with rising vertical pressure, while the compressive modulus increased first, then reduced and then increased with the increase of vertical pressure; the shear strength indexes all showed an increasing trend with the increased content of burnt rock-solid waste particles; when the content of burnt rock-solid waste particles was 50%, the compressibility of mixed soil was the lowest, the shear strength was the largest, and the compaction effect and shear resistance were the best. However, when the content of burnt rock particles was 10 ~ 20%, the shear strength of the soil improved significantly within the content range. The mechanism of burnt rock-solid waste to enhance the strength of the loess structure was mainly to reduce the porosity and average area of soil, significantly improve the strength and stability of mixed soil particles, and thus significantly improve the mechanical properties of soil. The results of this research will provide technical support for safe engineering construction and geological disaster prevention and control in loess areas.

show abstract

Laboratory Experiments and Numerical Simulation Study of Composite-Material-Modified Loess Improving High-Speed Railway Subgrade

Cited by 13 publications

References 40 publications

3D FEM Analysis of the Subsoil-Building Interaction

3D FEM Analysis of the Subsoil-Building Interaction

Long-term monitoring and analysis of the longitudinal differential settlement of an expressway bridge–subgrade transition section in a loess area

Experimental study on basic engineering properties of loess improved by burnt rock

Contact Info

Product

Resources

About