Ground movements due to deep excavations in Shanghai: Design charts

Bolton, M. D.; Lam, S. Y.; Vardanega, Paul J.; Ng, Charles Wang Wai; Ma, Xianjue

doi:10.1007/s11709-014-0253-y

Cited by 33 publications

(12 citation statements)

References 25 publications

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“…In general, a lower value of approximately 0.3 to 0.4 was obtained for normally consolidated clays that were sampled and set up in an isotropic stress state (Vardanega et al 2012b andBolton et al 2014). A higher value of about 0.5 to 0.6 fitted the data of overconsolidated kaolin (Vardanega et al 2012b), and 0.6 also coincided with the mean value obtained for the 19 natural clays and silts analysed in Vardanega and Bolton (2011).…”

Section: Mobilization Of Moderate Strengths In Claysupporting

confidence: 60%

“…Lam and Bolton (2011) later developed a refined approach using an energy balance on the same mechanism as the key to the calculation method. Bolton et al (2014) used this technique to present MSD-based design charts for deep excavations in Shanghai soil deposits, validated against a databse of field construction records. The scatter evident in the field data is a good indication of the uncertainty inherent in making design assumptions, especially, to the extent of the ground deformation mechanism defined by the elevation below which wall and soil displacements would be negligible.…”

Section: Mobilizable Strength Designmentioning

confidence: 99%

“…Figure 4 shows the clear division between deeper and shallower excavations for the field data available. Figure 4 shows design lines that capture the variation ψ* and η* using full MSD analysis (Lam and Bolton 2011) and with upper, middle, and lower bound profiles of undrained strength variation with depth, approximated for Shanghai in Bolton et al (2014).…”

Section: Mobilizable Strength Designmentioning

confidence: 99%

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Design of Geostructural Systems

Vardanega

Bolton

2016

ASCE-ASME J. Risk Uncertainty Eng. Syst., Part A: Civ. Eng.

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This paper begins with an extensive review of the literature covering the development of design rules for geostructural systems, beginning with traditional global safety factors and developing through partial factors for loads and resistances, and then considering the use of mobilization factors to limit soil strains. The paper then aims to distinguish two possible functions for geotechnical factors: to compensate for the uncertainty regarding soil strength, and to limit soil deformations that could compromise the associated structure before the soil strength can be fully mobilized, whatever it is. At present, design procedures generally conflate and confuse ultimate limit state (ULS) checks and serviceability limit state (SLS) deformation checks. Furthermore, most geotechnical engineers wrongly associate ULS with soil failure rather than with structural failure. The paper addresses this fundamental confusion by advocating mobilizable strength design (MSD), which is based on assumed soil-structure deformation mechanisms rather than soil failure mechanisms. It is argued that designs using MSD can guard against damaging structural deformations, either small deformations giving SLS or large structural deformations that must be regarded as ULS even though the associated soil strength may not yet be fully mobilized. This distinction effectively challenges much of the previous literature on limit state design principles for geotechnical applications, even where probabilistic approaches have been proposed. Nevertheless, the paper is informed by the concepts and techniques of decision making under uncertainty, and the paper concludes by considering whether MSD can also be placed in a reliability framework.

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Section: Mobilization Of Moderate Strengths In Claysupporting

confidence: 60%

Section: Mobilizable Strength Designmentioning

confidence: 99%

Section: Mobilizable Strength Designmentioning

confidence: 99%

See 1 more Smart Citation

Design of Geostructural Systems

Vardanega

Bolton

2016

ASCE-ASME J. Risk Uncertainty Eng. Syst., Part A: Civ. Eng.

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“…Apart from the six parameters used in the original paper, Bolton et al (2014) has newly introduced another two important parameters for deep excavations, i.e., modified system stiffness EI=γ w λ 4 and modified mobilization parameter ψ Ã . In the context of cantilever deflection, these two parameters affect assessment of the correction factor η.…”

Section: Dimensionless Groups For Deep Excavationsmentioning

confidence: 99%

Closure to “Characterization of Model Uncertainty for Cantilever Deflections in Undrained Clay” by D. M. Zhang, K. K. Phoon, H. W. Huang, and Q. F. Hu

Zhang

Phoon

Huang

et al. 2016

J. Geotech. Geoenviron. Eng.

165

207

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“…In recent years, recyclable and prefabricated supporting structures and technologies have been proposed to solve these problems. Steel sheet piles and jet-grouted columns with H steel piles have been widely applied to foundation pits [14][15][16][17]. Steel sheet piles and soil mixing walls can solve the problem of construction pollution and material recovery to some extent, but there are still some limitations in engineering applications [18].…”

Section: Introductionmentioning

confidence: 99%

Test Study on the Stress and Deformation Behaviors of a Shaft Supported by a Prefabricated Prestressed Structure

et al. 2019

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Soil deformation control is the key to shaft support. To better control soil deformation, improve construction efficiency, and reduce pollution, this study proposed a prefabricated prestressed supporting structure. The structure consisted of prefabricated steel structure units and special prestressed components. The structure units were applied to retain the soil. The screws were used for prestressing. Field prototype tests were conducted to assess the support effects and analyze the stress and deformation behaviors of the shaft. The earth pressure, the stress in the structure unit, and the lateral displacement of the soil were monitored. The measured earth pressure varied between the earth pressure at rest and the passive earth pressure. The stress of the supporting structure was far less than the yield strength of steel. Changes in the earth pressure and structural stress can be divided into four stages: rapid attenuation, fluctuation, slow change, and stabilization. Both the earth pressure and the structure stress completed the major attenuation within three days of prestressing. The surrounding soil moved out from the shaft under prestress conditions and exhibited an obvious space-time effect. The study of stress and deformation provides guidance for the construction of newly prefabricated prestressed structures.

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Ground movements due to deep excavations in Shanghai: Design charts

Cited by 33 publications

References 25 publications

Design of Geostructural Systems

Design of Geostructural Systems

Closure to “Characterization of Model Uncertainty for Cantilever Deflections in Undrained Clay” by D. M. Zhang, K. K. Phoon, H. W. Huang, and Q. F. Hu

Test Study on the Stress and Deformation Behaviors of a Shaft Supported by a Prefabricated Prestressed Structure

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