Research progress and development trends of highway tunnels in China

He, Chuan; Wang, Bo

doi:10.1007/s40534-013-0029-4

Cited by 55 publications

(12 citation statements)

References 14 publications

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“…The core idea of the NTM is rock classification based on the Q system. High-performance materials are applied as a permanent support, with a secondary lining only set as required by leakage, frost and other hazardous conditions [39]. In squeezing conditions, rapid installation of support and careful control of construction quality are recommended.…”

Section: Empirical Correlationsmentioning

confidence: 99%

Modified criterion for prediction of tunnel deformation in non-squeezing ground conditions

Daraei

Zare

2018

J. Mod. Transport.

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The strength factor-based criterion for tunnel deformation prediction proposed by Hoek in 2000 is reckoned to be the most practical criterion among the tunnel deformation criteria since 1980s. In view of the fact that Hoek's criterion was obtained based on case studies under squeezing ground conditions, it has a limited range of applications, applicable mainly in squeezing tunnels. In this work, this criterion was modified by taking into consideration the conditions of eight unstable stations in three non-squeezing tunnels in Iran to amplify its application range. Relative displacements and strength factor (defined as a strength-to-stress ratio) were obtained in unstable stations first. Then, the parametric values were plotted on a Cartesian coordinate's plane. By using the optimal regression line passing through all points, a criterion for prediction of tunnel deformation was proposed finally. A comparison made between the measured values and the ones predicted by the new criterion shows that the variance accounted for was 77% and the root mean square error was 2%, an acceptable accuracy and a small error implying the effectiveness of the new criterion in tunnel deformation prediction. In addition, the results show that the strength factor of 0.38 can be used to determine the boundary between squeezing and non-squeezing conditions; the behavior and type of failure of the tunnel would be predictable by use of the strength factor.

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Section: Empirical Correlationsmentioning

confidence: 99%

Modified criterion for prediction of tunnel deformation in non-squeezing ground conditions

Daraei

Zare

2018

J. Mod. Transport.

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“…Tunnels play an important part in the development of economics and society, and they have many uses such as transportation, including canals, trains, metros, road vehicles, etc., for mining ores, and for conducting sewage and water [1][2][3]. It has been estimated that the length of the tunnels constructed annually since 2013 reaches approximately 5200 km, and that the current tunnelling market represents 6-7% of the global infrastructure construction market.…”

Section: Introductionmentioning

confidence: 99%

Ground Deformation Characteristics Induced by Mechanized Shield Twin Tunnelling along Curved Alignments

Guo

et al. 2021

Advances in Civil Engineering

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This paper investigates the ground deformation characteristics induced by mechanized shield twin tunnelling along curved alignments by adopting the nonlinear three-dimensional (3D) finite element method (FEM). The performance of the adopted FEM is demonstrated to be satisfactory by comparing the numerical analysis results with the field monitoring data in a typical case history and with the predicted results generated by a modified version of the Peck’s empirical Gaussian formula. It has been found that the tunnelling-induced transverse ground surface settlement troughs and the distributions of the subsurface horizontal and vertical ground displacements are mostly similar in both form and magnitude for the considered various radii of curvature of tunnel alignment including 50 m, 100 m, 150 m, 200 m, 250 m, 300 m, 400 m, and infinity (i.e., straight-line tunnel). Considering the variational characteristics of the ground deformations with the magnitude of the radius of curvature, the radius of curvature of 100 m can be regarded as a critical tunnel alignment radius of curvature controlling the transformation of the curved tunnelling-induced ground deformational behaviors. For the benefit of geotechnical engineers interested in curved tunnelling with a small radius of curvature, a discussion of the technologies for reducing the overexcavation and improving the accuracy of tunnel lining segment installation is also presented.

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“…There has also been some research on the changes in pollutants of vehicles, influence factors, and control strategies [ 12 , 13 ], which showed historical changes in emissions and the effects of control measures. As the capital of China, Beijing has experienced rapid economic and social development and adopted a series of measures to control vehicle pollution [ 14 , 15 ]. The actual vehicle types and speed of on-road vehicles have undergone great changes.…”

Section: Introductionmentioning

confidence: 99%

Emission Variations of Primary Air Pollutants from Highway Vehicles and Implications during the COVID-19 Pandemic in Beijing, China

Cao

Tian

Shen

et al. 2021

IJERPH

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According to the traffic flow variation from January 2019 to August 2020, emissions of primary air pollutants from highway vehicles were calculated based on the emission factor method, which integrated the actual structure of on-road vehicles. The characteristics of on-highway traffic flow and pollution emissions were compared during various progression stages of coronavirus disease (COVID-19). The results showed that the average daily traffic volume decreased by 38.2% in 2020, with a decrease of 62% during the strict lockdown due to the impact of COVID-19. The daily emissions of primary atmospheric pollutants decreased by 29.2% in 2020 compared to the same period in 2019. As for the structure of on-highway vehicle types, the small and medium-sized passenger vehicles predominated, which accounted for 76.3% of traffic, while trucks and large passenger vehicles accounted for 19.7% and 4.0%, but contributed 58.4% and 33.9% of nitrogen oxide (NOx) emissions, respectively. According to the simulation results of the ADMS model, the average concentrations of NOx were reduced by 12.0 µg/m3 compared with the same period in 2019. As for the implication for future pollution control, it is necessary to further optimize the structure of on-highway and the road traffic vehicle types and increase the proportions of new-energy vehicles and vehicles with high emission standards.

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Research progress and development trends of highway tunnels in China

Cited by 55 publications

References 14 publications

Modified criterion for prediction of tunnel deformation in non-squeezing ground conditions

Modified criterion for prediction of tunnel deformation in non-squeezing ground conditions

Ground Deformation Characteristics Induced by Mechanized Shield Twin Tunnelling along Curved Alignments

Emission Variations of Primary Air Pollutants from Highway Vehicles and Implications during the COVID-19 Pandemic in Beijing, China

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