Effects of important factors on surface settlement prediction for metro tunnel excavated by EPB

Chakeri, Hamid; Özçelik, Yılmaz; Ünver, Bahtiyar

doi:10.1016/j.tust.2013.02.002

Cited by 113 publications

(53 citation statements)

References 14 publications

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“…So tail void grouting appears to be an important process in shield tunnel and has an important influence on the resulting settlement and on the loading on the surrounding soil. A large amount of research methods for prediction surface settlement induced by the shield tunnel have been developed over these years and can be summarized in empirical methods [1][2][3][4][5][6][7][8], analytical methods [9][10][11][12][13][14][15][16], and numerical simulation [17][18][19][20][21]. In recent years, artificial neural network [22][23][24] has been developed for analysis of surface settlement caused by the shield tunnel.…”

Section: Introductionmentioning

confidence: 99%

Analytical Method for Evaluating the Ground Surface Settlement Caused by Tail Void Grouting Pressure in Shield Tunnel Construction

Zhu

2018

Advances in Civil Engineering

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e tail void grouting is a key step in shield tunnel construction and has an important influence on the loading on the surrounding soil and on the resulting settlement. In order to estimate the ground surface settlement caused by tail void grouting pressure in tunnel construction, the loading on the surrounding soil is simplified as an expansion problem of the cylindrical cavity in semi-infinite elastic space. A simple analytical formula is deduced by using the virtual image technique and Fourier transform solutions. e effectiveness of the proposed method is verified by case studies. e effects of elastic modulus, tail void grouting pressure, tunnel radius, and tunnel depth on the ground surface heave are conducted. e results indicate that the computed results are in accordance with Ye's solution and it is more rational to consider the ground surface heave induced by tail void grouting pressure in the prediction of ground settlement due to shield excavation. Moreover, the ground surface heave owing to tail void grouting pressure resembled a Gaussian distributed curve. us, no matter the ground surface subsidence or ground surface heave can be predicted by means of adding the presented empirical formula to the Peck formula which cannot predict the ground surface heave. e ground surface heave decreases with an increase in elastic modulus. On the contrary, as the tail void grouting pressure and tunnel radius increase, the ground surface heave increases, respectively. e ground surface heave first steadily increases and then declines gradually with the tunnel depth increase.

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Section: Introductionmentioning

confidence: 99%

Analytical Method for Evaluating the Ground Surface Settlement Caused by Tail Void Grouting Pressure in Shield Tunnel Construction

Zhu

2018

Advances in Civil Engineering

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“…Ground surface settlement caused by tunnel excavation, especially in urban areas, has special significance. The process of these settlements differs according to the depth of excavation in different areas, increasing or decreasing depending on the depth of excavating (Melis et al, 2002;Chakeri et al, 2013;Papastamos et al, 2015). Notably, when excavation exceeds a certain depth, ground surface settlement will decrease (Boscardin and Cording, 1989;Guglielmetti et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Comparison of Mohr-Coulomb and Hardening Soil Models Numerical Estimation of Ground Surface Settlement Caused by Tunneling

Çelik¹

2017

jist

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Due to in depth tunnel excavation, tensions in the soil are eased, causing elastic and plastic deformations in the area of tunnel and leading to surface settlement at the ground level. Currently, along with the use of numerical methods in analysis and design of engineering projects, it is known that this method has used extensively in the analysis of problems related to geotechnical engineering and tunneling. Selection of the appropriate parameters and soil model can have a significant impact on the results of numerical analysis. The Mohr-Coulomb elastic-plastic model (MC) is one of the most widely used models, used in cases evaluating the hardness of materials, independent of the surface tension. If the Mohr-Coulomb used for numerical modeling of tunnel where in-depth tunneling excavation is involved and where an increase in maximum ground surface settlement and decrease in the reliability of stability of tunnels can be seen, which may not be appropriate in some conditions. The more appropriate model should be used to solve this problem, one that can model the hardness of materials based on changes in the level of stress. In this study, the maximum ground surface settlement due to tunnel excavation, obtained from Mohr-Coulomb model was compared with those of Hardening Soil (HS) Model results. Therefore, the ground surface settlement because of an assumption tunnel in different depths was analyzed with Mohr-Coulomb and Hardening Soil models by using PLAXIS 2D. As a result of the analyzes, it is observed that as the depth of the tunnel increases, the settlements on the ground surface decrease according to Mohr-Coulomb and approach the real values. Keywords: Finite Element Method, Material models, PLAXIS, Surface settlement, TunnelingÖZET: Zemin içinde yapılan tünel kazısı nedeniyle, zemindeki gerilmeler boşalarak kazı alanında elastik ve plastik deformasyonlara yol açmakta ve zemin yüzeyinde oturmalar meydana gelmektedir. Günümüzde, mühendislik projelerinin tasarım ve analizinde sayısal yöntemlerin kullanımı ile birlikte, Geoteknik mühendisliği ve tünel ile ilgili problemlerin çözümünde bu yöntemin yaygın bir şekilde kullanıldığına tanıklık etmekteyiz. Uygun parametrelerin ve zemin modelinin seçilmesi, nümerik analiz sonuçlarını üzerinde önemli etkiye sahiptir. Mohr-Coulomb (MC) elasto-plastik model malzemelerin sertliğinin yüzey gerilmelerden bağımsız olarak tanımlandığı durumlarda kullanılan en yaygın zemin davranış modellerinden biridir. Tünel modellemelerinde Mohr-Coulomb kullanılması halinde, kazı derinliği arttıkça zemin yüzeyindeki oturmaların gerçek değerlerden fazla çıktığı ve güvenilirliğin azaldığı görülmektedir. Bu problemin çözümü için, gerilme düzeyindeki değişikliklere bağlı olarak malzemelerin sertliğini modelleyebilen daha uygun bir davranış modeli kullanılmalıdır. Bu çalışmada, tünel kazısından dolayı Mohr-Coulomb modelinden elde edilen maksimum zemin yüzey oturmaları Pekleşen Zemin modeli (HS) ile karşılaştırılmıştır. Bu nedenle, varsayılan farklı derinliklerdeki bir tünelden dolayı z...

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“…The complicated simulations of 3D EPBS tunneling models using several parameters e.g., face pressure, shield element or shield weight, tunnel lining element, tail void grout process, hydraulic jack, steering control, and backup trailer loads were gradually introduced [13], [14]. The 3D FE models using face pressure, shield element, tunnel lining element, and grouting process as the parameters are used in studies [15], [16]. As the studies mentioned above, only four main parameters (face pressure, shield element, grouting process and lining element) are generally used to model the 3D EPBS tunneling.…”

Section: Introductionmentioning

confidence: 99%

“…In the grouting process in engineering practice, the grouting will change from the liquid state to solid. To realistically model this characteristic, solid elements having different stiffness are represented to simulate the grouting process [12], [15] and [19]. However, an actual behavior of initial grout is in a fluid state with no stiffness.…”

Section: Introductionmentioning

confidence: 99%

“…In this situation, shell elements which offer the direct quantification of lining structural forces are preferable. The shell elements have been also used in the past researches, e.g., the influence of ground stratification on lining force and settlement due to tunneling [19], the effects of tunneling on adjacent building and existing tunnel respectively [15], [16] and [20]. However, using the shell elements to model the tunnel lining causes a problem due to that the shell elements have no thickness in the process of meshing.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tunneling Simulation in Soft Ground Using Shell Elements and Grouting Layer

Lueprasert¹

2017

GEOMATE

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ABSTRACT:With the advancement of computer sciences and researches on tunneling simulation in the past, the 3D finite element analysis of tunnel excavation by Tunnel Boring Machines (TBMs) has been extensively used over the last decade. Due to that the complicated construction sequences and relevant loads can be taken into account, complex interaction problems can then be performed. Many simulation techniques have been proposed depending on the assumptions used in the modeling. For modeling the tunnel lining, solid elements are commonly used due to the ratio between the width and thickness of the lining is not large. In addition, most studies focused on the ground deformation, not the lining forces. In the circumstance that the lining forces are essentially observed, the structural elements that directly provide the values are preferred. Therefore, this research attempts to propose the shell elements as tunnel lining together with the grouting layer in the analysis. The analysis results from the proposed method and the conventional one are compared and discussed in terms of ground deformation and lining forces together with the field measurement data. The results reveal that the simulation by the proposed method is sufficient and can reasonably reproduce the soil and lining responses.

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Effects of important factors on surface settlement prediction for metro tunnel excavated by EPB

Cited by 113 publications

References 14 publications

Analytical Method for Evaluating the Ground Surface Settlement Caused by Tail Void Grouting Pressure in Shield Tunnel Construction

Analytical Method for Evaluating the Ground Surface Settlement Caused by Tail Void Grouting Pressure in Shield Tunnel Construction

Comparison of Mohr-Coulomb and Hardening Soil Models Numerical Estimation of Ground Surface Settlement Caused by Tunneling

Tunneling Simulation in Soft Ground Using Shell Elements and Grouting Layer

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