Mechanical Properties of Functionally Graded Concrete Lining for Deep Underground Structures

Li, Dechun; Xu, Chong Hai; Cui, Zhen-Dong; Chen, Jin‐Ming; Xu, Xiang-Qing; Zhang, Tong-Tong; Zhang, Zhaowei; Song, Gang

doi:10.1155/2022/2363989

Cited by 2 publications

(3 citation statements)

References 37 publications

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“…Particularly interesting for this study are the works devoted to theoretical analysis and numerical modeling of the structural heterogeneity of concrete. In [62], the mechanical properties of multilayer concrete lining for underground structures with a functional distribution of layers were studied. It has been established that the distribution of stresses in a multilayer concrete lining with a functional arrangement of layers largely depends on the inner radius, thickness and number of layers.…”

Section: Introductionmentioning

confidence: 99%

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Modeling and Calculation of Improved Centrifuged Reinforced Concrete Columns with Variotropic Structure

et al. 2023

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The use of vibro-centrifugation technology allows the manufacture of variotropic structures that are inhomogeneous in the annular section and have different characteristics along the section thickness. Hardening of the outer layers allows the structure to better resist bending conditions, however, the behavior of the variotropic column under central and eccentric compression remains unexplored. This article considers the problem of compression of hollow columns made of homogeneous concrete that is non-uniform in the annular section (variotropic), and is reinforced with steel reinforcing bars at different values of the load application eccentricity. Variotropic concrete obtained by vibro-centrifugation technology has a stronger outer part and a less durable inner part. The strength of a homogeneous column corresponds to the strength of the middle part of variotropic concrete. The problem was solved numerically in the ANSYS environment for a vertical column rigidly clamped at the bottom edge and loaded with eccentricity at the top edge. Three types of eccentricity are considered; e/r = 0, 0.16 and 0.32 (respectively 0 mm, 0.24 mm and 48 mm). The results of the solution in the form of stress fields, deformations and a pattern of crack development in a spatial setting are obtained. The results showed that for central compression, a homogeneous column has a better bearing capacity of 3.6% than a variotropic one. With the values of eccentricity e/r = 0.16 and 0.32, the variotropic column has a higher bearing capacity (by 5.5% and 6.2%) than the homogeneous one and better resists the development of cracks. The significance of the study lies in the practical application of the proposed approach, developed on a research basis, for non-trivial and complicated operating conditions of columns. This study influences the development of reinforced concrete structures and applies scientific findings to engineering practice.

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Section: Introductionmentioning

confidence: 99%

“…The ultimate breaking load depended mainly on the concrete strength, Poisson's ratio and the number of layers. Just as in single-layer supports, the destruction of a multilayer support began from its inner face [62]. The authors of [58] studied plane deformations of a hollow multilayer cylinder with a functional distribution of layers.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Calculation of Improved Centrifuged Reinforced Concrete Columns with Variotropic Structure

et al. 2023

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“…Differing from the mentioned works above, Zhang et al [22] pre-assumed the desired stress distribution with the elastic modulus E(r) being undermined, then the E(r) was confirmed by back-calculations according to the stress distribution and loadings. Li et al [23] studied the mechanical properties of the functionally graded concrete shaft lining with uniform confining pressure. However, all the above-mentioned works are based on axisymmetric loads, and the situation under non-axisymmetric loads has not been researched yet, such as linings of the subway tunnel.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of the Functionally Graded Lining for a Deep Buried Subway Tunnel

Zhang

Cui

et al. 2022

Applied Sciences

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With the rapid development of the subway rail transit, tunnels are buried at an increasing depth, raising the requirements of bearing capacity and waterproofness for linings. Functionally graded materials are introduced into the design of linings to save costs, and concrete with different elastic moduli is equipped at different positions to reduce the waste of materials, compared to the homogeneous lining. The significance of this study includes that the functionally graded lining for the buried subway tunnel is under the non-uniform confining pressure and the calculation model of internal force and deformation for the functionally graded lining is established. The elastic modulus of the lining is set to vary with the angle in the form of a power function, and the function parameters are analyzed on the basis of this model. The results show that the radial displacement of the lining axis decreases with the increase in a and b, but the deformation mode remains the same, and the reduction in deformation is smaller and smaller. With the increase in a and b, the distribution trend of the moment remains the same. The lateral pressure coefficient λ has a great impact on the safety of the structure, which exceeds the influence of the function parameters on the safety of the structure. The displacement of the lining axis and the section moment change linearly with the increase in λ. With the increase in λ, the shape of the lining changes significantly, which shows that the side with larger pressure deforms to the inside and the side with smaller pressure expands to the outside. When the maximum deformation occurs at 0°, the parameter a should be larger than b. When the maximum deformation occurs at 90°, the parameter b should be larger than a, so as to minimize the cost of materials and reduce the structural deformation. Finally, the numerical simulation is conducted to verify the theoretical results, showing that the calculation model of internal force and deformation is suitable for the cylinder with t/R≤0.2, and there is a certain gap between the theoretical calculation and numerical simulation, but the largest gap of the displacement is within 8%. Compared with Function I, Function II has some advantages in reducing the maximum deformation of the structure, but the advantages are relatively low. The analysis results have significant reference value for designers and relevant scholars.

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Mechanical Properties of Functionally Graded Concrete Lining for Deep Underground Structures

Cited by 2 publications

References 37 publications

Modeling and Calculation of Improved Centrifuged Reinforced Concrete Columns with Variotropic Structure

Modeling and Calculation of Improved Centrifuged Reinforced Concrete Columns with Variotropic Structure

Mechanical Properties of the Functionally Graded Lining for a Deep Buried Subway Tunnel

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