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Mechanized tunneling is a well-established construction technology that allows for tunnel advances in a wide range of geological environments, high ground water pressures or small cover depths often met in urban tunneling. During the design and construction of shield-driven tunnels, a reliable prognosis of the tunneling-induced effects as well as c...
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... In this section, a SA has been done to identify the parameters that have the most relevant on the advancement of TBM from the given range of model parameters in the studied section of the TML2 project. According to the researchers, the sensitivity of the model parameters strongly depends on the range of selected parameters and the purpose of the evaluation (Ninić 2016). In this study, the elementary effect of 17 soil parameters and 2 operation parameters relevant to TBM on the surface settlement in the monitoring point is investigated. ...
In this article, the ability of the artificial neural network-genetic algorithm (ANN-GA) to perform back analysis and predict maximum surface settlement in mechanised tunnelling is investigated. The required data of the ANN meta-model was generated using 150 three-dimensional finite-difference simulations. The global sensitivity analysis was performed on 19 parameters, including 17 geotechnical parameters of soil layers and 2 operational parameters of face pressure and grouting pressure. The predicted results using ANN were in good agreement with the numerical simulations so that R = 99% and rRMSE = 1.5% are obtained. Then, back analysis was performed using the ANN-GA hybrid algorithm and the geotechnical data of the monitoring point were updated using the maximum surface settlement monitored at this point. Also, for the geotechnical parameters considered in the design phase, using the same algorithm, the number of operational parameters required for optimal settlement was predicted.
... Short-term loads caused by the tail gap pressure were monitored [42], and long-term loads acting around the linings, such as earth and water pressures, were also monitored [17,43]. To further understand the variation regulations of loads with time in real time, a process-oriented model was proposed [44,45], which can produce a more reasonable analysis of groundwater flow and slurry hardening during the construction of the linings. A typical load distribution around the tunnel linings and the temporal and spatiotemporal evolution of earth and water pressures are shown in Figures 1 and 2, respectively. ...
The introduction and development of shield tunnels have led to the innovation of precast segmental linings, which has significant advantages in improving the construction speed compared with in-situ cast concrete linings. However, damage of the linings and water leakage at the lining joints highlight defects in the design and construction of the linings. In this regard, it is necessary to investigate the failure mechanism of linings for shield tunnels and evaluate the waterproofing performance and repercussions of lining joints. The relevant research results published in recent years are reviewed in this paper, focusing on the failure mechanisms of linings and the waterproofing performance of lining joints. Progressive failure and instability of linings are introduced. Progressive failure has three stages: initial elastic stage, local damage stage, and overall failure stage. The performance-based design of joint waterproofing is described in seven steps. Further opportunities for the investigation of this topic are discussed.
... EBs found also use in the modelling of piles subjected to different modes of loading, namely lateral [33], passive [34,35], and dynamic loading [36]. More recently, use cases suggest the incorporation of EBs to capture the response of tension members, including tunnel front fiberglass reinforcements [37], rock bolts [38], ground anchors [39], and soil nails [40]. ...
... As suggested by [10,38,41], the numerical behaviour of embedded beam formulations is numerically validated against SFEA results (i.e., full 3D FE model). In the latter case, the swept meshing technique [57] is applied to discretize the domain with 84,148 10-noded tetrahedral elements. ...
The numerical analysis of many geotechnical problems involves a high number of structural elements, leading to extensive modelling and computational effort. Due to its exceptional ability to circumvent these obstacles, the embedded beam element (EB), though originally intended for the modelling of micropiles, has become increasingly popular in computational geotechnics. Recent research effort has paved the way to the embedded beam element with interaction surface (EB-I), an extension of the EB. The EB-I renders soil-structure interaction along an interaction surface rather than the centreline, making it theoretically applicable to any engineering application where beam-type elements interact with solid elements. At present, in-depth knowledge about relative merits, compared to the EB, is still in demand. Subsequently, numerical analysis are carried out using both embedded beam formulations to model deep foundation elements. The credibility of predicted results is assessed based on a comprehensive comparison with the well-established standard FE approach. In all cases considered, the EB-I proves clearly superior in terms of mesh sensitivity, mobilization of skin-resistance, and predicted soil displacements. Special care must be taken when using embedded beam formulations for the modelling of composite structures.
... Although empirical methods are convenient, without considering the realistic incorporation of all the relevant spatial-temporal interactions occurring during tunneling, their application situation is limited (Meschke, 2018). Numerical methods can model the complex tunneling processes by incorporating constitutive models for rocks/soils, complex boundary conditions and dynamic construction procedures (Lyu et al., 2020;Ninić, 2015;Wu et al., 2020b). However, geological parameters required for model development and calibration are not readily available, and uncertainties are inevitably embedded in model parameters. ...
This study proposes an artificial intelligence approach to predict ground settlement during shield tunneling via considering the interactions among multi-factors, e.g., geological conditions, construction parameters, construction sequences, and grouting volume and timing. The artificial intelligence approach employs a hybrid neural network model that incorporates a differential evolution algorithm into the artificial neural network (ANN). The differential evolution algorithm is used to determine the optimized architecture and hyperparameters of ANN. The adaptive moment estimation (Adam) method is then employed to facilitate the training process of ANN. On the strength of Adam, the differential evolution algorithm is further enhanced to process a large number of ANN candidates without consuming massive computing resources. The proposed hybrid model is applied to a field case of ground settlements during shield tunneling in Guangzhou Metro Line No. 9. Geological conditions and shield operation parameters are first characterized and quantified by a feature extraction strategy, then input for the model. Results verifies the accuracy of prediction using the proposed hybrid model. Moreover, shield operation parameters with high influence on ground settlement are identified through a partial derivatives sensitivity analysis method, which can provide guidance for shield operation.
... This fact increases the interest in using reverse parameter identification techniques and optimization algorithms in geotechnical modeling to update real materials and model parameters at specific stages of construction. This technique has been applied to recognize soil parameters in laboratories or in-situ tests (Zhao et al., 2015), estimation of excavation support systems (Nini c et al., 2013), tunnel excavation in rock (Nini c & Meschke, 2015), TBM cutter head design (Xia et al., 2015), design of reinforced concrete structure (Khatibinia et al., 2013) and embankment construction on soft soils (Nini c, 2016). ...
... There are many available methods for global optimization such as meteheuristic optimization algorithms, Genetic algorithms (GA), Evolutionary Strategies (ES) and swarm intelligence that can be used for geotechnical problems (Nini c, 2016). In some geotechnical researches, back analysis and optimization problems with swarm intelligence methods like PSO optimization, have shown good performance (Calvello & Finno, 2004;Feng et al., 2006;Jurado-Piña & Jimenez, 2015;Kang et al., 2013;Nini c et al., 2017;Schanz & Meier, 2008;Song et al., 2011;Zhang et al., 2009;Zhao et al., 2015). ...
In this research, three- dimension finite difference method was applied to simulate the tunnel excavation by earth pressure balance (EPB) boring machine of Tehran Metro Line 7 tunnel in Iran. Sensitivity analysis and parameter identification was carried out by Morris Elementary Effect method to evaluate the relative sensitivity of model for each input parameter. Then, artificial neural network (ANN) was used as a meta model to predict model response for the dataset of selected sensitive parameters. For this purpose, 100 numerical simulation has carried that a database including 1500 data was compiled for using in ANN. Thereafter, PSO algorithm was employed as a parameter identification technique to find the optimized values of the parameters according to monitoring surface settlement. Also, after material identification, the same PSO-ANN algorithm was used to optimize operation parameter (face pressure). The results showed that ANN prediction and numerical simulation with initial set of parameters has more than 98% concordance with about 2.4% RMSE and 0.014 MAE for all dataset. The optimized parameters gained via back analysis enable the meta model to well predict the ground settlement in the about 15 seconds.
... Les deux modélisations les plus complètes du creusement avec un tunnelier ont été présentées par Ninić (2015). La première s'appuie sur les possibilités offertes par le logiciel PLAXIS 3D et la deuxième sur le logiciel EKATE développé à Ruhr université de Bochum. ...
Le développement de l’urbanisme privilégie de plus en plus souvent la solution souterraine. Le creusement d’environ 200km de tunnels est prévu dans les dix prochaines années en France seulement, en milieu urbain dense.L’excavation d’une cavité dans un terrain engendre des mouvements dans le massif. Le front de taille se déplace généralement instantanément vers l’excavation. A ce déplacement d’extrusion s’ajoute la convergence des parois du tunnel. A faible profondeur, ces mouvements risquent de se propager jusqu'à la surface du terrain constituant une cuvette de tassement qui peut conduire à des désordres importants voire de nature accidentelle (tassements différentiels, développement de fontis, effondrement de constructions, etc.). Plusieurs paramètres influencent la qualité des simulations et la prévision des déplacements induits par le creusement d’un tunnel. Le choix d’une loi de comportement est primordiale pour la modélisation des tunnels qui dépend de la réponse du sol en termes de déformations. La prédiction des déplacements engendrés requière un modèle de comportement du sol rigoureux qui puisse simuler le plus fidèlement possible la réponse du sol.Cette thèse propose un modèle de comportement adapté à la simulation du creusement de tunnel avec un mécanisme d’écrouissage déviatorique dans le cadre de la théorie de l’état critique. Ce modèle reproduit de manière satisfaisante la réponse non linéaire du sol à l’échelle des essais de laboratoire et présente une alternative sécuritaire pour les simulations à l’échelle de la structure.L’effet de l’influence de plusieurs paramètres sur la simulation des tunnels est étudié à travers des simulations 2D et 3D avec différentes configurations et en considérant le couplage hydromécanique. Le modèle proposé est aussi utilisé pour la reproduction de mesures in-situ d’une section de tunnel du Grand Paris.
... The simulation results from the advanced numerical model ekate has been compared with registered data from several tunnel projects such as the Wehrhahn metro line in Düsseldorf, Germany [36], the L9 tunnel in Barcelona [33]. In general, the simulation results and measurement data show a good agreement that enables the application of the numerical FE model to real-world tunnel problems. ...
Finite Element simulation is a possible tool to investigate interactions between the Tunnel Boring Machine and the surrounding soil. Surface
settlements can be predicted in real-time based on simulation results by machine learning surrogate models. However, to train such models,
large amounts of computationally intensive simulations are required. To accomplish this step with minimal costs, we propose a hybrid active
learning approach to select the minimal amount of simulations necessary to build an accurate model. During the tunnel construction, the realtime
settlements prediction model will be used to analyze associated risks to ensure safe and sustainable constructions in urban areas.
... Examples of calculation focusing on the influence of technology have been carried out by Ochmański et al. (2015) for NATM tunnel with provisional support of jet grouting canopies, by Lambrughi et al. (2012), Do (2013), Oh and Ziegler (2014), Comodromos et al. (2014), Fargnoli (2015 for mechanized heading tunnelling. In addition to these works, a program named Enhanced Kratos for Advanced Tunnelling Engineering (EKATE) Meschke, 2004, 2006;Nagel, 2009;Ninić, 2015) has been undertaken in the last decade to systematically analyse the role of tunnelling methodology. All the above studies have the merit of investigating and explaining on a rational mechanical basis the noticeable influence of the EPB technology normally observed on site and to replace the subjectivity currently introduced in design with more realistic assumptions. ...
Tunnelling is often considered an exclusive field of experts with countless years of practice mostly because of a grey area existing between design carried out with sophisticated theories and construction ruled by practical judgement. Despite the auxiliary actions carried out during execution are acknowledged to affect significantly the interaction between soil and lining, limited effort is made to analyse their effects with an appropriate theoretical support, often preferring to perform broad estimate with arbitrary coefficients. The present paper aims to establish a common field between designers and executors, trying to take advantage on one side of the
increased power of numerical computation, on the other side of the accurate control of equipment nowadays available. A three-dimensional numerical model is then built to simulate tunnelling with Earth Pressure Balance,
characterising with great detail the properties of the various materials and the geometrical and mechanical
characteristics of excavation. The calculation is superintended by a script that automatizes the assignment of
input and the interpretation of output, allowing in this way to perform repetitive parametric analyses. The tool is
firstly tested on a real case study, a section of the MRTA project of Bangkok, then applied to quantify the effects
of the pressure applied on the tunnel face and of the gap left between lining and soil. The calculation shows the
time evolution of the mechanisms induced by excavation and lining installation and their modification induced
by a parametric change of the main technological factors.
... Recently, the FE model has been supplemented with various new features, such as a paralellisation strategy to reduce the computation time (Bui and Meschke, 2015), an automatic simulation model generation and execution concept based on a Tunnel Information Model and a re-meshing technique for realistic modelling of the excavation and advancement processes . More details about the numerical simulation model can be found in Ninić (2015) and Meschke et al. (2011). ...
... The analyses are performed to determine the important parameters which are sensitive to the objective of the model, i.e. the surface settlement. In this paper, this topic is not described and readers are referred to Ninić (2015). By varying the deterministic values of input parameters (both geotechnical and process parameters), deterministic output data (surface settlements) are collected from simulations based on the FE model ekate representing a specific tunnel from time step 1 to n. ...
... Recently, the FE model has been supplemented with various new features, such as a paralellisation strategy to reduce the computation time (Bui and Meschke, 2015), an automatic simulation model generation and execution concept based on a Tunnel Information Model and a re-meshing technique for realistic modelling of the excavation and advancement processes . More details about the numerical simulation model can be found in Ninić (2015) and Meschke et al. (2011). ...
... The analyses are performed to determine the important parameters which are sensitive to the objective of the model, i.e. the surface settlement. In this paper, this topic is not described and readers are refered to Ninić (2015). By varying the deterministic values of input parameters (both geotechnical and process parameters), deterministic output data (surface settlements) are collected from simulations based on the FE model ekate representing for a specific tunnel from time step 1 to N. The deterministic input-output data set is utilised to establish a deterministic surrogate model as introduced in Freitag et al. (2015). ...
