Deformation analysis of tunnel excavation below existing pipelines in multi‐layered soils based on displacement controlled coupling numerical method

Zhang, Zhiguo; Huang, Maosong; Zhang, Mengxi

doi:10.1002/nag.2098

“…A series of centrifuge tests were undertaken to understand the soil-pipe interaction and investigate effects of tunnelling on buried pipelines (e.g., Vorster et al [12], Marshall et al [13], and Shi et al [14,15]). Capable of analysing problems over complicated domains and approximating the complex tunnel-soil-pipeline interaction, numerical methods (such as the finite element method and the finite difference method) were widely used to model tunnelling effect on buried pipelines (e.g., Hunter [16], Wang et al [17], Zhang et al [18,19], Z. Zhang and M. Zhang [20], Wham et al [21], Shi et al [22], and Shi et al [23]). Analytical solution of pipelines subjected to differential ground movement that were normally used by engineers in design office as an initial design step was presented (e.g., Trifonov and Cherniy [24], Karamitros et al [25], Kouretzis et al [26], Saiyar et al [27], Ni and Mangalathu [28], and Ni et al [29]).…”

Section: Introductionmentioning

confidence: 99%

An Investigation into the Tunnel‐Soil‐Pipeline Interaction by In Situ Measured Settlements of the Pipelines

Li

¹

,

Wang²,

Yang

³

2020

Advances in Civil Engineering

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Response of buried pipeline to tunnelling is of great concern in the subway construction. It is of paramount importance but difficult to estimate the influence of tunnelling on adjacent pipelines because of the complex tunnel-soil-pipeline interaction. The technique of in situ measured settlements of buried pipelines remains the standard approach for understanding this interaction and addressing the issue. The Huangzhuang station of the Beijing Subway is located in a densely populated area, with many buried pipelines in the close proximity; the shallow tunnelling method of pile-beam-arch (PBA method) was used to excavate the station tunnels; the shallow tunnelling of the station tunnels inevitably causes settlements of the ground surface and the buried pipelines. Direct monitoring of the pipelines by digging holes from the ground surface was performed during the station tunnel construction. In situ measured settlements of the ground surface and the buried pipelines caused by the subway construction were obtained. It is observed from the obtained results that the pipeline settlement development can be divided into four stages that are associated with different construction periods of the PBA method. Sharp increases in the pipeline settlement occurred in the specific stages (stages 2 and 4). It is concluded from comparisons between the pipeline settlement and the ground surface settlement that separation between steel or cast iron pipelines and the soil beneath occurs due to the tunnel construction. And the pipeline settlement is smaller than that of the ground surface. This finding has the practical implication that the ground surface can be monitored instead of the buried pipeline. Using this indirect pipeline monitoring, the pipeline safety can be conservatively evaluated. This study is an example for evaluating the shallow tunnelling-induced effects on adjacent buried pipelines and understanding the tunnel-soil-pipeline interaction under similar conditions.

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“…Soil stratification is essential in geotechnical site characterisation and structural design (Houlsby & Houlsby, 2013;Wang et al, 2014). Recent studies have reported the significant effect of soil stratification on the design of foundations, tunneling and pipelines (Burd & Frydman, 1997;Padrón et al, 2008;Huang & Griffiths, 2010;Zhang et al, 2012;Lee et al, 2013;White et al, 2014). The identification of soil stratification includes determining soil types, the number of soil layers, the thickness of each layer and soil properties.…”

Section: Introductionmentioning

confidence: 99%

Probabilistic identification of soil stratification

Li

¹

,

Cassidy

²

,

Huang

³

et al. 2016

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Identification of soil stratification is vital to geotechnical structural design and construction where the soil layer, soil type and properties are necessary inputs. Although methods are available for classifying the soil profiling using measured cone penetration test (CPT) data, the identification of soil stratification at unsampled locations is still difficult due to significant variability of natural soil. The identification is further complicated by the considerable uncertainties in the CPT measurements and soil classification methods. This study aims to develop a probabilistic method to predict soil stratification at unsampled locations by explicitly filtering the uncertainties in soil classification systems. An established Kriging interpolation technique is used to estimate the CPT parameters which are further interpreted to identify the soil stratification. Equations are derived to quantify the degree of uncertainties reduced by this method. The approaches are illustrated using a database of 26 CPT tests recently sourced from a dike near Ballina, Australia. Results show that the majority of the uncertainties in the soil parameters are screened by a soil classification index. The remaining uncertainties are further filtered by the soil classification systems. A clear stratification with a high degree of confidence is obtained in both horizontal plane and vertical unsampled locations, which shows excellent agreement with the existing CPT tests. This study provides a methodology to clearly identify the soil strata and reduce the uncertainties in prediction of design properties, paving the way for a more cost-effective geotechnical design.

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“…Soil stratification is essential in geotechnical site characterisation and structural design (Houlsby & Houlsby, 2013;Wang et al, 2014). Recent studies have reported the significant effect of soil stratification on the design of foundations, tunneling and pipelines (Burd & Frydman, 1997;Padrón et al, 2008;Huang & Griffiths, 2010;Zhang et al, 2012;Lee et al, 2013;White et al, 2014). The identification of soil stratification includes determining soil types, the number of soil layers, the thickness of each layer and soil properties.…”

Section: Introductionmentioning

confidence: 99%

Probabilistic identification of soil stratification

Li¹,

Zhang²,

Cassidy³

et al. 2015

Géotechnique

0

View full text Add to dashboard Cite

Identification of soil stratification is vital to geotechnical structural design and construction where the soil layer, soil type and properties are necessary inputs. Although methods are available for classifying the soil profiling using measured cone penetration test (CPT) data, the identification of soil stratification at unsampled locations is still difficult due to significant variability of natural soil. The identification is further complicated by the considerable uncertainties in the CPT measurements and soil classification methods. This study aims to develop a probabilistic method to predict soil stratification at unsampled locations by explicitly filtering the uncertainties in soil classification systems. An established Kriging interpolation technique is used to estimate the CPT parameters which are further interpreted to identify the soil stratification. Equations are derived to quantify the degree of uncertainties reduced by this method. The approaches are illustrated using a database of 26 CPT tests recently sourced from a dike near Ballina, Australia. Results show that the majority of the uncertainties in the soil parameters are screened by a soil classification index. The remaining uncertainties are further filtered by the soil classification systems. A clear stratification with a high degree of confidence is obtained in both horizontal plane and vertical unsampled locations, which shows excellent agreement with the existing CPT tests. This study provides a methodology to clearly identify the soil strata and reduce the uncertainties in prediction of design properties, paving the way for a more cost-effective geotechnical design.

show abstract

Deformation analysis of tunnel excavation below existing pipelines in multi‐layered soils based on displacement controlled coupling numerical method

Cited by 28 publications

References 37 publications

An Investigation into the Tunnel‐Soil‐Pipeline Interaction by In Situ Measured Settlements of the Pipelines

An Investigation into the Tunnel‐Soil‐Pipeline Interaction by In Situ Measured Settlements of the Pipelines

Probabilistic identification of soil stratification

Probabilistic identification of soil stratification

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