Deep tunnel fronts in cohesive soils under undrained conditions: a displacement-based approach for the design of fibreglass reinforcements

Prisco, Claudio di; Flessati, Luca; Porta, Davide

doi:10.1007/s11440-019-00840-8

Cited by 10 publications

(16 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many researchers have focused on the evaluation of normal forces to study the loadtransfer mechanism of EB along the pile length (for example, see [13,24,37]). Skin traction profiles, in contrast, have received only subordinate attention.…”

Section: Influence Of Mesh Size On Mobilization Of Skin Tractionmentioning

confidence: 99%

“…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].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Practice-Oriented Validation of Embedded Beam Formulations in Geotechnical Engineering

Granitzer

Tschuchnigg

2021

Processes

View full text Add to dashboard Cite

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.

show abstract

Section: Influence Of Mesh Size On Mobilization Of Skin Tractionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Practice-Oriented Validation of Embedded Beam Formulations in Geotechnical Engineering

Granitzer

Tschuchnigg

2021

Processes

View full text Add to dashboard Cite

show abstract

“…In the past, numerous authors analysed the mechanical response of reinforced faces by using experimental (Calvello & Taylor, 1999;Juneja et al, 2010;di Prisco et al, 2018a;Kamata & Mashimo, 2003;Yoo & Shin, 2003), numerical (Chen et al, 2013;di Prisco et al, 2019b;di Prisco et al, 2020;Peila, 1994;Yoo & Shin, 2003) and theoretical approaches. Among the theoretical approaches, in the engineering practice it is popular the one proposed in Grasso et al (1989), in which the effect of reinforcements is converted into an 'equivalent cohesion', whose value is introduced in either the limit equilibrium (Horn, 1961) or the limit analysis (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…For deep tunnel faces under undrained conditions, as was discussed by di Prisco et al (2018b), the approaches based on either the limit equilibrium method or the limit analysis theory, cannot be considered to be suitable as design tools. In this case, in fact, owing to the continuous and ductile spatial propagation of the plastic domain, the face response is stable, even if the associated face displacements are not acceptable.…”

Section: Introductionmentioning

confidence: 99%

“…In this case, in fact, owing to the continuous and ductile spatial propagation of the plastic domain, the face response is stable, even if the associated face displacements are not acceptable. Recently, the authors proposed an alternative design approach (di Prisco et al, 2020) based on the definition of a characteristic curve, putting in relation the face displacements to the applied face pressure, obtained by performing FEM numerical analyses under undrained conditions. In this paper, its practical application is discussed with reference to a realistic case chosen by the authors.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Deep tunnel faces in cohesive soils under undrained conditions: application of a new design approach

Flessati

Prisco

2020

European Journal of Environmental and Civil Engineering

Self Cite

View full text Add to dashboard Cite

Tunnel faces excavated under particularly difficult ground conditions are commonly supported. In case of conventional tunnelling, this support is provided by either improving the mechanical properties of the soil or introducing linear inclusions. This latter technique, consisting in the introduction of fibreglass pipes in the face, is particularly popular since it is very simple to tailor to the different conditions encountered during the excavation the reinforcement spatial distribution. In the current engineering practice, this stabilisation technique is designed by employing simplified approaches not allowing the face displacement estimation. For this reason, in case of deep tunnels in cohesive soils under either undrained or 'partially drained' conditions, these approaches cannot be employed. In this paper, the authors present the practical application of a new displacement based design approach, based on the definition of the face characteristic curve, putting in relation the face displacement to the stress applied on the face.

show abstract

Mathematical modelling of the mechanical response of geosynthetic‐reinforced and pile‐supported embankments

Mangraviti

Flessati

Prisco

2023

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

Piled foundations are commonly employed to reduce settlements in artificial earth embankments founded on soft soil strata. To limit the number of piles and, consequently, construction costs, popular is the use of geosynthetic reinforcements laid at the embankment base. Nowadays, the complex interaction between geosynthetics, piles and soil is not yet fully understood and, in the scientific literature, simplified displacement‐based approaches to choose reinforcements, pile diameter and spacing are missing. In this paper, the authors, starting from the critical analysis and theoretical interpretation of finite difference numerical results, introduce a new mathematical model to rapidly assess both (i) differential/average settlements at the top of the embankment and (ii) maximum tensile forces in the basal reinforcement. The model, conceived to reproduce the response of a pile belonging to the central part of the embankment, is the result of an upscaling procedure based on a suitable sub‐structuring of the spatial domain (an axisymmetric unit cell) and on the concept of plane of equal settlements. For the foundation soil, drained conditions are considered, the pile skin roughness is disregarded, and piles are assumed to get the rigid bedrock. As generalised kinematic variables average and differential settlements are employed, whereas as generalized static ones the embankment height and the geosynthetic axial force. The model is validated against field measurements (where layered foundation soil and pile caps are included) and an application example of the model, used as a preliminary design tool in a displacement‐based perspective, is finally provided.

show abstract

Deep tunnel fronts in cohesive soils under undrained conditions: a displacement-based approach for the design of fibreglass reinforcements

Cited by 10 publications

References 31 publications

Practice-Oriented Validation of Embedded Beam Formulations in Geotechnical Engineering

Practice-Oriented Validation of Embedded Beam Formulations in Geotechnical Engineering

Deep tunnel faces in cohesive soils under undrained conditions: application of a new design approach

Mathematical modelling of the mechanical response of geosynthetic‐reinforced and pile‐supported embankments

Contact Info

Product

Resources

About