Stability of Tunnels in Cement-Admixed Soft Soils with Spatial Variability

Tyagi, Akanksha; Liu, Yong; Pan, Yutao; Ridhwan, Khaliesah Bte Mohamed; Lee, Fook Hou

doi:10.1061/(asce)gt.1943-5606.0001988

Cited by 15 publications

(5 citation statements)

References 23 publications

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“…Additionally, as the artificial crust stress changed over time, the time of the maximum tensile stress should be known. e tensile stress-time curves are shown in Figure 5, which indicates that the largest tensile stress occurs in the middle of the crust [16]. e data presented in Figure 5 also show that the tensile stress increases with the load but decreases at equal loading because of the consolidation of the subsoil.…”

Section: Tension Stress Of the Crustmentioning

confidence: 89%

“…It is common to apply numerical simulation method to describe the characteristics of soil in the geotechnical engineering, and the results of numerical analysis compared with the field engineering or model test are effective depending on the suited constitutive model of soil materials. In addition, it is difficult to obtain accurate results of the analytical calculation owing to the limitation and complexity, so there is a vast literature on methods to solve the behavior of pile-supported embankments using the finiteelement method (FEM) [4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

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Two‐Dimensional Parametric Study of an Embankment on Clay Improved by an Artificial Crust Composite Foundation

Wang

Chen

et al. 2020

Advances in Civil Engineering

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In order to reduce the foundation settlement, conserve resources, and be environmental-friendly while increasing the use of soil resources, an artificial crust layer formed by in situ stabilization is proposed to combine with prestressed pipe piles over soft ground in road construction. In this study, a centrifuge test and two-dimensional coupled-consolidation finite-element analyses are conducted to simulate the construction of an embankment. And a two-dimensional parametric study is conducted to study the performance indicated by maximum long-term settlement, excess pore water, and tensile stress under various conditions. The results of the centrifuge test clearly show that the measured settlement, excess pore water, and tensile stress are in good agreement with the calculated results. In addition, the key factors of pile spacing and thickness and strength of the crust have an influence on the maximum settlement, stress of the foundation, and tensile stress of the crust using the two-dimensional coupled-consolidation finite-element analyses. And the stress transfer regular of the foundation is analyzed under various conditions. Moreover, the failure of the crust contained tensile cracking and shearing failure and the thickness of the pile that pierced the crust are also affected by the key factors.

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Section: Tension Stress Of the Crustmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Two‐Dimensional Parametric Study of an Embankment on Clay Improved by an Artificial Crust Composite Foundation

Wang

Chen

et al. 2020

Advances in Civil Engineering

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“…The tunnel stability problem is derived from the difficulties encountered in the construction of underground projects (Huang et al, 2019;Liu et al, 2020;Kumar and Sahoo, 2021;Zhang et al, 2022b). The research work on it is also one of the essential manifestations of the close connection between theory and reality (Lee et al, 2006;Wilson et al, 2011;Tyagi et al, 2018;Rahaman and Kumar, 2020;Li et al, 2021). Those problems have been analyzed and summarized by researchers and engineers, e.g., the classification and failure mechanism of the surrounding rock by observing and monitoring the mechanical indicators and anomaly phenomena of the surrounding rock during the tunnel construction process.…”

Section: Introductionmentioning

confidence: 99%

“…All research and practice are aimed at better ensuring the stability of the construction solution to support the tunnel surrounding rock (Dias, 2011;Pan and Dias, 2017;Park et al, 2017;Zare Naghadehi et al, 2019;Bai et al, 2021b;Zhang et al, 2022a). Thus, researchers have conducted various studies on the mechanical state, deformation state, and stability of the surrounding rock through theoretical, experimental, numerical, and field monitoring methods to study the tunnel burial depth, hole diameter, excavation plan, and support plan (Tyagi et al, 2018;Antão et al, 2021;Kumar and Sahoo, 2021;Shiau and Al-Asadi, 2022). These research results have greatly enriched and improved the knowledge of tunnel construction theory and practice.…”

Section: Introductionmentioning

confidence: 99%

The construction stability of large section tunnel considering the deterioration of clay mechanical properties

Huang

Liu

Ma³

et al. 2023

Front. Mater.

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The stability of large-section clay tunnels is closely related to the mechanical behavior of the surrounding rock. The mechanical behavior of the surrounding rock is characterized by the coupled response of the physico-mechanical properties of the clay material and the tunnel construction conditions. Therefore, this paper proposes a numerical experimental study based on the response surface method to quantitatively link the stability of large-section clay tunnels with construction factors. It will provide a basis for quantitatively guiding the tunnel construction plan adjustment to ensure its stability. Firstly, the tunnel stability reserve is evaluated by considering the deterioration of physico-mechanical properties of clay surrounding rocks, and the relationship between the tunnel stability index and construction factors is established according to Taylor’s theorem. Secondly, the response surface method and the steepest ascent method are used to find the optimal fitting relationship between the tunnel stability reserve factor and tunnel construction factors. Finally, the analysis of a tunnel application shows that (a) the stability evaluation considering the deterioration of physical and mechanical properties of clay is well representative; (b) the “curved” region of the response of the tunnel stability reserve factor can be effectively determined by the steepest slope method; (c) for the “curved” region, a second-order response surface is more appropriate. This research will reveal the coupling relationship between tunnel stability, physico-mechanical properties of clay, and tunnel construction conditions, which will contribute to the development of intelligent tunnel construction.

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“…Cement can improve the engineering properties of soft soil, and the UCS of cement soil increases with the increase in curing age. So, cement soil is widely used in many engineering fields, just as bored pile construction, shield tunnel construction, and underground diaphragm wall construction [13][14][15][16][17][18][19][20][21]. Many studies on the mathematical model of strength growth were conducted.…”

Section: Introductionmentioning

confidence: 99%

The Time Effect and Micromechanism of the Unconfined Compressive Strength of Cement Modified Slurries

Jiang

Chen

Zhou

et al. 2021

Advances in Materials Science and Engineering

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This study investigated the unconfined compressive strength change law of cement modified slurries (CMS) under different curing ages. We conducted unconfined compressive strength tests using slurry and cement as raw materials. The cement contents were 5%, 10%, 15%, 20%, and 25%. The curing ages were 7, 14, 28, 56, 90, 120, 150, and 180 d. A time effect model of CMS strength was established based on the measured UCS strength-curing age and the strength-cement content curves. The test results proved that the UCS of the CMS increased significantly with an increase in the curing age, and after 90 days, the UCS gradually increased to a fixed value. The time effect model better characterized the relationship between the UCS of the CMS and the curing age and the cement content, as the predicted value had a high correlation with the measured value. We conducted scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) tests to analyze the microstructure and chemical composition of the CMS. The microscopic test results demonstrated that the increase of cement content and curing age increased the amount of gelling substances in the CMS and made the overall structure more compact, thereby increasing its macro strength.

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Stability of Tunnels in Cement-Admixed Soft Soils with Spatial Variability

Cited by 15 publications

References 23 publications

Two‐Dimensional Parametric Study of an Embankment on Clay Improved by an Artificial Crust Composite Foundation

Two‐Dimensional Parametric Study of an Embankment on Clay Improved by an Artificial Crust Composite Foundation

The construction stability of large section tunnel considering the deterioration of clay mechanical properties

The Time Effect and Micromechanism of the Unconfined Compressive Strength of Cement Modified Slurries

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