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Abstract

This paper presents the design method and the construction details of a subsonic low-speed wind tunnel, which has been designed to achieve the flow velocity of 35 m/s in the measurement section with expected uniform velocity field at its inlet. To achieve such objectives a very detailed design was performed using a theoretical 1D analysis and computational fluid dynamics simulations. This approach was applied to improve the flow quality along the wind tunnel sections. When the wind tunnel has been launched a direct comparison of the experimentally measured flow field in the test section and numerical simulation results was conducted. Such comparison of the simulation results with the experimental one is presented in this paper. The obtained results confirm that assumed wind tunnel design method was correct, i.e. the pressure drop in the wind tunnel has been predicted very well and drive system is effective and sufficient to accelerate the airflow to required values.
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Bibliography

[1] Barlow J.B., Rae Jr W.H., Pope A.: Low-Speed Wind Tunnel Testing. John Wiley and Sons; New York 1999.
[2] Bradshaw P., Pankhurst R.C.: The design of low-speed wind tunnels. Prog. Aerosp. Sci. 5(1964), 1–69.
[3] Anderson J.D. Jr.: Fundamentals of Aerodynamics (5th Edn.). McGraw-Hill; 2011.
[4] Kneba Z.: Modeling of the internal combustion engine cooling system. Arch. Thermodyn. 40(2019), 3, 109–121.
[5] Muszynski T., Andrzejczyk R., Park W.I., Dorao C.A.: Heat transfer and pressure drop characteristics of the silicone-based plate heat exchanger. Arch. Thermodyn. 40(2019), 1, 127–143.
[6] Mehta J., Bradshaw P.: Design rules for small low speed wind tunnels. Aeronaut. J. 83(1979), 827, 443–453.
[7] Stathopoulos T.: Design and fabrication of a wind tunnel for building aerodynamics. J. Wind Eng. Ind Aerod. 16(1984), 2–3, 361–376.
[8] Cattafesta L., Bahr C., Mathew J.: Fundamentals of wind-tunnel design. In: Encyclopedia of Aerospace Engineering. John Wiley and Sons, Hoboken 2010.
[9] Bell J.H., Mehta R.D.: Boundary-layer predictions for small low-speed contractions. AIAA J. 27(1989), 3, 372–374.
[10] Noor A., Ed.: Wind Tunnel Designs and their Diverse Engineering Applications. IntechOpen, 2013.
[11] Discetti S., Ianiro A., Aref H.: Experimental Aerodynamics. CRC Press – Taylor & Francis Group; Boca Raton 2017.
[12] Idelchik I.E.: Handbook of Hydraulic Resistance. Coefficients of Local Resistance and of Friction. US Atomic Energy Commission and the National Science Foundation. Washington DC 1966.
[13] Ansys Fluent Fluid Simulation Software https://www.ansys.com/products/fluids/ ansys-fluent (access: 5 Jan. 2020).
[14] Ansys Meshing https://www.ansys.com/products/platform/ansys-meshing (access: 5 Jan. 2020).
[15] Ochrymiuk T.: Numerical analysis of microholes film/effusion cooling effectiveness. J. Therm. Sci. 26(2017), 5, 459–464.
[16] Szwaba R., Ochrymiuk T., Lewandowski T., Czerwinska J.: Experimental investigation of microscale effects in perforated plate aerodynamics. J. Fluids Eng. 135(2013), 12, 121104-1-10
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Authors and Affiliations

Ryszard Szwaba
1
Krzysztof Hinc
1
Tomasz Ochrymiuk
1
Zbigniew Krzemianowski
1
Piotr Doerffer
1
Marcin Kurowski
1

  1. Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk, Poland
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Abstract

The paper presents an analysis of determining the load of a model tunnel lining in a noncohesive soil medium at two different heights of soil backfill above the structure. A series of simulations were performed with the flexible and rigid tunnel lining. The analysis was performed by conducting simulations with the use of an author’s program based on the discrete element method. The model previously calibrated on the basis of laboratory tests was used. The loads acting on the structure, the distribution of stresses in the surrounding soil medium and the displacements of this medium in the vicinity of the structure were determined and compared. The effect of soil weight and technological load applied from the surface was taken into account. The values of the numerically obtained loads of the tunnel lining were compared with those calculated according to the classic Hewett’s method.
It has been proven that in both cases the degree of cooperation between the structure and soil is significantly related to the rigidity of the structure, hence the loads determined may differ significantly from the results obtained according to classical methods. It was shown that discrete modelling allows to reflect differences in the behaviour of the soil medium resulting from different heights of soil backfill. Smaller horizontal pressure was obtained in the side zones of an excavation at a higher backfill. In addition, significantly greater intensity of vertical soil displacements over the lining were observed with a lower backfill height.
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Authors and Affiliations

Paweł Szklennik
1
ORCID: ORCID

  1. Military University of Technology, Faculty of Civil Engineering and Geodesy, ul. Gen. Sylwestra Kaliskiego 2 00-908 Warsaw, Poland
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Abstract

In order to study the ground disturbance and the influence relationship between the two tunnels during the construction of the new shield tunnel undercrossing the existing high-speed railway tunnel, the centrifuge test was used to simulate the construction of the parallel shield tunnel undercrossing the high-speed railway tunnel, and the variation law of the internal force, segment deformation and surface settlement of the existing high-speed railway tunnel undercrossing the shield was studied. It is found that the adverse effects caused by the later tunnel are less than those caused by the first tunnel excavation. For the existing tunnels without settlement joints, the longitudinal settlement of the inverted arch and the vault is U-shaped and anti-U-shaped respectively. The settlement value of the ground surface and the existing tunnel is increased by more than 100%. When the shield passes through the high-speed railway tunnel, the transverse bending strain is larger than the longitudinal, and special attention should be paid at the corner.
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Authors and Affiliations

Ruizhen Fei
1 2
ORCID: ORCID
Limin Peng
1
ORCID: ORCID
Chunlei Zhang
2
ORCID: ORCID
Jiqing Zhang
2
ORCID: ORCID
Peng Zhang
2
ORCID: ORCID

  1. Central South University, School of Civil Engineering, Changsha, 410075, China
  2. China Railway Design Corporation, Tianjin, 300142, China
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Abstract

Since the establishment of the People’s Republic of China, the country has made significant progress in tunnel construction, transforming from a “weak tunnel nation” to a “strong tunnel nation.” As of 2022, China has undertaken more than 60 projects involving large-diameter shield tunnels. To promote the sustainable and high-quality development of large-diameter shield tunnels in China, this article systematically reviews the development history of large-diameter shield tunnels, summarizes the current projects in the country, and addresses various aspects such as construction technology management, design technology, ecological conservation, safety, and intelligence. The article also provides suggestions for the development of large-diameter shield tunnels in China, with the aim of playing a proactive role in promoting their advancement.
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Authors and Affiliations

Wei Qiu
1
ORCID: ORCID
Xin Dong
1
ORCID: ORCID
Linjian Su
1
ORCID: ORCID
Xingwei Xue
2
ORCID: ORCID
Kexin Zhang
2
ORCID: ORCID

  1. Engineering Department, Guangzhou Expressway Co., LTD, China
  2. School of Transportation and Surveying Engineering, Shenyang Jianzhu University, China
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Abstract

This paper provides an analysis of the evacuation process in a road tunnel in the event of a fire, using the example of the tunnel under the Luboń Mały mountain currently being constructed on Expressway S7’s Lubień – Rabka-Zdrój section. As fires are the largest and most dangerous events occurring in road tunnels, it is important to predict the evacuation process as early as at the design stage. The study described here used numerical modelling to simulate evacuation, which made it possible to determine the required safe evacuation time of all tunnel users in a fire. On the basis of the parameters of the tunnel under Luboń Mały, numerical studies were performed for four different fire scenarios, three of which assumed various fire locations with the currently designed two traffic lanes. The fourth variant accounted for the planned extension of the roadway to include three traffic lanes. Eventually, four numerical models were developed involving various fire ignition locations and numbers of potential tunnel users. The values of initial-boundary conditions used in the simulation, such as movement speed during evacuation, shoulder breadth and pre-movement time, were specified on the basis of experimental data for an evacuation performed in smoke conditions in the Emilia tunnel in Laliki. The results lead to the conclusion that if the time of reaching critical conditions in the tunnel is not shorter than 5 minutes 40 seconds for the current design state and 5 minutes 47 seconds for three lanes, the distribution of evacuation exits in the tunnel under Luboń Mały will ensure safe evacuation.
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Bibliography

[1] C . Caliendo, M.L. De Guglielmo, Accident rates in road tunnel and social costs evaluation. SIIV – 5th International Congress – Sustainability of Road tunnels Infrastructures. In Procedia – Social and Behavioural Sciences 53, 166- 177 (2012).
[2] A . Voeltzel, A. Dix, A comparative analysis of the Mont Blanc, Tauern and Gotthard tunnel fires. World Road Association (PIARC ) 324, 18-34 (2004).
[3] I . Maevski, Design Fires in Road Tunnels, A synthesis of Highway Practice. New York: Transportation Research Board NCHR P National Cooperative Highway Research Program Synthesis 415. (2011).
[4] British Standard. The application of fire safety engineering principles to fire safety design of buildings. Human factors. Life safety strategies. Occupant evacuation, behaviour and condition, BSI. PD 7974-6:2004.
[5] E . Ronchi, P. Colonna, J. Capote, D. Alvear, N. Berloco, A. Cuesta, The evaluation of different evacuation models for assessing road tunnel safety analyses. Tunnelling and Underground Space Technology 30, 74-84 (2012). doi: 10.1016/j.tust.2012.02.008
[6] E . Ronchi, M. Kinsey, Evacuation models of the future: insights from an online survey of user’s experiences and needs. Advanced Research Workshop – Evacuation and Human Behaviour in Emergency Situations 145-155 (2011).
[7] N. Schmidt-Polończyk. Ocena możliwości stosowania wentylacji wzdłużnej w długich tunelach drogowych. Assessment of the possibility to apply longitudinal ventilation in long road tunnels. PhD thesis, AGH UST (2016).
[8] Road Tunnels: Operational Strategies for Emergency Ventilation. France: PIARC Committee on Road Tunnels (2011).
[9] M . Kinateder, P. Pauli, M. Müller, J. Krieger, F. Heimbecher, I. Rönnau, Human behaviour in severe tunnel accidents: Effects of information and behavioural training. Transportation Research Part F: Traffic Psychology and Behaviour 17, 20-32 (2013). doi: 10.1016/j.trf.2012.09.001
[10] E . Ronchi, K. Fridolf, H. Frantzich, D. Nilsson, A.L. Walter, H. Modig, A tunnel evacuation experiment on movement speed and exit choice in smoke. Fire Safety Journal 97, 126-136 (2018). doi: 10.1016/j.firesaf.2017.06.002
[11] M . Seike, N. Kawabata, M. Hasegawa, Evacuation speed in full-scale darkened tunnel filled with smoke. Fire Safety Journal 91, 901-907, (2017). doi: 10.1016/j.firesaf.2017.04.034
[12] C. Casse, S. Caroly, Analysis of critical incidents in tunnels to improve learning from experience. Safety Science 116, 222-230 (2019), DOI : 10.17632/scrdwnzc7t.1
[13] K . Fridolf, E. Ronchi, D. Nilsson, H. Frantzich, The representation of evacuation movement in smoke-filled underground transportation systems. Tunnelling and Underground Space Technology 90, 28-41 (2019), doi: 10.1016/j. tust.2019.04.016
[14] J. Porzycki, N. Schmidt-Polończyk, J. Wąs, Pedestrian behavior during evacuation from road tunnel in smoke condition – Empirical results. PLOS ONE 13 (8), e0201732 (2019). doi: 10.1371/journal.pone.0201732
[15] I. Donald, D. Canter, Intentionality and fatality during the King’s Cross underground fire. European Journal of Social Psychology 22 (3), 203-218 (1992).
[16] K . Fridolf, D. Nilsson, H. Frantzich, Fire Evacuation in Underground Transportation Systems: A Review of Accidents and Empirical Research. Fire Technology 49 (2), 451-475 (2013). doi: 10.1007/s10694-011-0217-x
[17] Thunderhead Engineering. Pathfinder 2014.2 Verification and Validation (2014).
[18] Thunderhead Engineering. Pathfinder 2016. User Manual (2016).
[19] P. Liszka, Ocena bezpieczeństwa ewakuacji w tunelu pod Luboniem Małym. Master’s Thesis, AGH University of Science and Technology (2018).
[20] P.G. Gipps, B. Marksjo, A microsimulation model for pedestrian flows. Mathematics and Computers in Simulation 27, 95-105 (1985).
[21] M . Moussaïd, N. Perozo, S. Garnier, D. Helbing, G. Theraulaz, The Walking Behaviour of Pedestrian Social Groups and Its Impact on Crowd Dynamics. PLOS ONE. 5 (4), 1-7 (2010). doi: 10.1371/journal.pone.0010047
[22] RABT : Forschungsgesellschaft fur Strassen-and Verkehrswesen, Richtlinien fuer Ausstattung und Betrieb von Strassentunneln (2006).

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Authors and Affiliations

Natalia Schmidt-Polończyk
1
ORCID: ORCID
Zbigniew Burtan
1
ORCID: ORCID
Piotr Liszka
1

  1. AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

Effects of temperature variation on the performance of silicon heterojunction solar cells are studied using opto-electrical simulations. It is shown that the low-temperature cell efficiency is determined by the fill factor, while at high temperatures it depends on the open-circuit voltage. Simulations revealed that the low-temperature drop in the fill factor is caused by poor tunnelling, in particular at the ITO/p-a-Si:H heterojunction. The authors link this drop in fill factor to a low maximum-power-point voltage and show how poor tunnelling is reflected in the charge redistribution determining the device voltage. The effect of the contact work function on temperature behaviour of efficiency by varying the electron affinity of ITO layers has been demonstrated. It was also demonstrated that increasing the electron affinity of ITO on the p-side minimises the work function mismatch, leading to significant improvements in efficiency, especially at low temperatures, while optimisation on the n-side results in marginal improvements over the entire temperature range. In addition to the cumulative effects of the temperature-dependent parameters, their individual contributions to the efficiency were also investigated. Moreover, it was presented that the thermal energy (kT) determines the efficiency temperature behaviour, while other parameters play only a minor role. This paper shows how temperature variations affect device performance parameters.
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Bibliography

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Authors and Affiliations

Jošt Balent
1
ORCID: ORCID
Marko Topič
1
ORCID: ORCID
Janez Krč
1
ORCID: ORCID

  1. University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000 Ljubljana, Slovenia
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Abstract

Earth Pressure Balanced shields are currently the most utilized tunnelling machines throughout around the world. The possibility of using conditioning agents that change the mechanical and hydraulic behaviour of a soil, changing it into a plastic paste and thus permitting soil pressure applications at the tunnel face, is the key point to explain the increasing utilization of this technology. Despite its great importance, not much laboratory researches can be registered on soil conditioning, particularly for cohesionless soils. The conditioning criterion is usually defined on the basis of a trial-and-error procedure developed directly at the job sites. A test that is able to simulate the extraction of soil from the bulk chamber with the screw conveyor inclined upwards, as in real machines, can offer a quantitative indication of the conditioned soil behavior for EPB use. The characteristics of the device and the results obtained on many different types of soil are discussed in order to point out the great importance and quality of results that can be achieved using the proposed test device.

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Authors and Affiliations

Luca Borio
Daniele Peila
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Abstract

Ground settlement during and after tunnelling using TBM results in varying dynamic and static load action on the geo-stratum. It is an undesirable effect of tunnel construction causing damage to the surface and subsurface infrastructure, safety risk, and increased construction cost and quality issues. Ground settlement can be influenced by several factors, like method of tunnelling, tunnel geometry, location of tunnelling machine, machine operational parameters, depth & its changes, and mileage of recording point from starting point. In this study, a description and evaluation of the performance of the arti?cial neural network (ANN)was undertaken and a comparison with multiple linear regression (MLR) was carried out on ground settlement prediction. The performance of these models was evaluated using the coefficient of determination R2, root mean square error (RMSE) and mean absolute percentage error (MAPE). For ANN model, the R2, RMSE and MAPE were calculated as 0.9295, 4.2563 and 3.3372, respectively, while for MLR, the R2, RMSE and MAPE, were calculated as 0.5053, 11.2708, 6.3963 respectively. For ground settlement prediction, bothANNandMLRmethodswere able to predict significantly accurate results. It was further noted that the ANN performance was higher than that of the MLR.
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Authors and Affiliations

Baoping Zou
1
ORCID: ORCID
Musa Chibawe
1
ORCID: ORCID
Bo Hu
1
ORCID: ORCID
Yansheng Deng
1
ORCID: ORCID

  1. School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310023, China
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Abstract

The main problem of tunnelling with use of TBM in highly dense urban areas is to assign the range of subsiding trough and the impact of tunnelling works on existing buildings and underground or road infrastructure. The paper presents the results of settlements calculations over twin tube metro tunnel using analytical, empirical methods. The tunnel external diameter is 6,5 m ; the overburden vary from 5 m to 8 m ; the distance between tunnel axis is 14 m. Because of quaternary soils and high water table level the TBM type EBP was chosen as the method of tunnel construction. At the length of 502 m of tunnel the monitoring system was carried out in 22 cross sections. The results of settlements monitoring were compared with the values of analytical calculations.

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Authors and Affiliations

A. Siemińska-Lewandowska
R. Kuszyk
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Abstract

This study presents a fuzzy analytic hierarchy process (FAHP) by integrating analytic hierarchy process (AHP) and fuzzy cognition to evaluate the construction risks of tunnel portals. Wuguanyi Tunnel is taken as the research objective to validate the performance of the proposed method. The result shows that the proposed decision making method can effectively identify risk factors and determine the risk level during the construction of tunnel portals. Finally, the corresponding control measures during the construction of the Wuguanyi Tunnel portal are proposed according to the risk assessment results.

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Authors and Affiliations

Xianghui Deng
ORCID: ORCID
Rui Wang
ORCID: ORCID
Tian Xu
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Abstract

The historical past of a building has a key influence on the variability of geotechnical conditions. These conditions change with a modification of the structural system, a change in function or only architectural elements (fashionable in a given period). In the article, various geotechnical and geophysical surveys are described, which led to a discovery of potential causes of a structural failure at historical Castle of Dukes of Pomerania in Szczecin. The investigation resulted in a discovery of an underground tunnel system constructed under the Castle, which existence was only suspected. The tunnels were constructed primarily during II World War, but also before that period. The article summarizes facts discovered due to investigation as well as historical and geological background related to the execution of the reinforced concrete and masonry tunnels. The lesson learned resulting from this discovery is that great care should be taken when historical areas are considered, even if the structure seems to be massive and robust.
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Authors and Affiliations

Tomasz Godlewski
1
ORCID: ORCID
Radosław Mieszkowski
2
ORCID: ORCID
Maciej Maślakowski
3
ORCID: ORCID

  1. Building Research Institute, 21 Ksawerów St., 02-656 Warsaw, Poland
  2. Warsaw University, Geology Department, 93 Zwirki i Wigury St., 02-089 Warsaw, Poland
  3. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
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Abstract

The impact of TBM EPB tunnelling was assessed with respect to the observed values of settlements as the results of extensive monitoring system of the subsoil and ground surface. The aim of the analysis using empirical methods was to determine the real scale of impact and to determine the formula for the asymmetric subsidence trough observed during the passage of two TBMs in quaternary cohesive soils. Based on field measurements, authors propose the polynomial formulation for the depth and shape of the asymmetric subsidence trough prediction over twin tube TBM tunnel.
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Authors and Affiliations

Rafał Kuszyk
1
ORCID: ORCID
Anna Siemińska-Lewandowska
2
ORCID: ORCID

  1. Ph.D., Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
  2. Prof., DSc., PhD., Eng., Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
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Abstract

One of major design problems associated with shallow tunnelling in urbanized areas is the prediction of ground displacements caused by the construction process. Advanced tunnelling techniques such as shield tunnelling using Earth Pressure Balance Tunnel Boring Machines (EPB-TBMs) allow for significant reductions of settlements observed at the ground surface in comparison to tunnelling methods used in the past. The predictions of these displacements are often based on semi-empirical methods and prior experience. In addition to relative simplicity of such methods, their robustness and decades of validation in many tunnelling projects make them attractive for practical use. The tunnelling-induced settlement trough at the ground surface can be described by inversed Gaussian distribution function. It requires only the assumption of two parameters, namely: expected volume loss (VL) and the distance to the point of inflection (iy ), which is dependent on the empirical trough width parameter (K) and the tunnelling depth (z0). The values of those parameters have a strongly empirical nature; they should be established based on comparable experience obtained from full scale tunnelling projects with similar technique and at similar ground conditions. The paper presents the problem of variability of those parameters and discusses the need for its assessment. As volume loss is strongly related to the tunnelling technique, the study focuses on EPB-TBM tunnelling as the most commonly implemented one in recent years. Variability of parameters observed for different ground conditions in different countries is summarized. Finally, preliminary assessment of variability of settlements observed in Warsaw region is presented.
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Authors and Affiliations

Witold Bogusz
1
ORCID: ORCID
Tomasz Godlewski
1
ORCID: ORCID
Anna Siemińska-Lewandowska
2
ORCID: ORCID

  1. Building Research Institute, Filtrowa 1, 00-611 Warsaw, Poland
  2. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
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Abstract

This paper presents a 3D finite element analysis of the effect caused by a blast inside a reinforced concrete tunnel. The simulated explosion was caused by the crash of a heavy vehicle transporting inflammable material (LPG). The finite element technique was used to analyze the structural problems on the tunnel reinforced concrete structure considering the fire action and the subsequent explosion (blast) effect, incorporating appropriate material models.
Through FEM software the tunnel behavior was described with regard to structural safety. Indeed, tunnels must be designed to withstand damage factors, so it is desirable that if such an explosion did occur, the tunnel should be able to return to service in safety as soon as possible with minor repairs. Therefore, following the presented analysis, the most important factors influencing the dynamic response and the damage of the structure could be identified. The simulation involved aspects of thermal analysis and structural problems and the tensions in the structure generated by the effect of temperature caused by the fire and by the blast overpressure were analyzed. Following this approach, the most important factors influencing the dynamic response and damage of structure can be identified and appropriate preventive measures can be designated.
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Authors and Affiliations

Giovanni Leonardi
1
ORCID: ORCID
Rocco Palamara
1
ORCID: ORCID
Federica Suraci
1
ORCID: ORCID

  1. Department of Civil, Energy, Environmental and Materials Engineering, University of Reggio Calabria, Via Graziella, Reggio Calabria, Italy
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Abstract

The article describes the behaviour of the flysch rock massif (Carpathian flysch) during the drilling of three tunnels in the preliminary lining. These tunnels were excavated in: “Naprawa”, “Laliki”, and “Świnna Poręba”. The distance between these tunnels in a straight line was 50 km to 90 km. The results of the displacement of the contours of these tunnels and their convergence were analysed in detail. These values were compared with the indices used to assess the behaviour of the rock mass in the tunnel environment (Zasławski index and Hoek index) and the adopted limit values of displacements and deformations. On this basis, a critical analysis of the selection of initial supports in the completed tunnels was made, showing errors at the design stage.
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Authors and Affiliations

Antoni Tajduś
1
ORCID: ORCID
Krzysztof Tajduś
2
ORCID: ORCID

  1. Faculty of Civil Engineering and Resource Management, AGH University of Science and Technology, Mickiewicza 30 av., 30-059 Cracow, Poland
  2. Strata Mechanics Research Institute, Polish Academy of Science, 27 Reymonta Str., 30-059 Krakow, Poland
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Abstract

The running speed of high-speed trains in the tunnel is as high as 350 km, which is very sensitive to the construction disturbance of the new shield tunnel. Therefore, it is of positive significance to study the influence of shield tunneling on existing high-speed railway lines and tunnel structures and control standards. Combined with centrifuge test and three-dimensional numerical simulation, the dynamic response of shield tunnel undercrossing existing high-speed railway tunnel is studied, and the influence of settlement joint and steel pipe pile reinforcement on existing tunnel is analyzed. Studies have shown that the existence of existing tunnels will reduce the surface settlement caused by tunnel excavation, but this shielding effect will be reduced if the influence of construction joints is considered. Therefore, if the construction joint is not considered in the numerical calculation, the ground deformation will be underestimated and the mechanical performance of the existing tunnel structure will be overestimated. In addition, steel pipe piles can effectively control the settlement of existing tunnels.
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Authors and Affiliations

Ruizhen Fei
1 2
ORCID: ORCID
Limin Peng
1
ORCID: ORCID
Chunlei Zhang
2
ORCID: ORCID
Jiqing Zhang
2
ORCID: ORCID
Peng Zhang
2
ORCID: ORCID

  1. Central South University, School of Civil Engineering, Changsha, 410075, China
  2. China Railway Design Corporation, Tianjin, 300142, China
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Abstract

This paper presents a review of models of the current transport in different kind of heterojunctions (HJs) and their characteristics. In order to effectively deduce the dominant electron transport for the HJs based on ZnO or Zn1−xMgxO layers grown on Si substrate by MBE a comparison is performed – which type of the HJ exhibits better electrical properties. The current–voltage characteristics for the studied HJs were measured within 280–300 K. The transport properties of the HJs are explained in terms of Anderson model with reference to aforementioned current transport models. It is found, that the mechanisms of current transport for all of the studied HJs are similar. At a low forward voltage bias the tunneling current dominates while at medium voltage bias (0.5–1 V) multitunneling capture-emission prevails with the electron trap located at 0.1–0.25 eV below the bottom of a ZnO (Zn1−xMgxO) conduction band. Beyond this voltage bias space charge limited current governs the current transport.

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Authors and Affiliations

E. Płaczek-Popko
K.M. Paradowska
M.A. Pietrzyk
A. Kozanecki
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Abstract

The following paper presents wind tunnel investigation of aerodynamic characteristics of hovering propellers. This propulsion system may be applied on a lightweight Quad Plane VTOL (Vertical Take-Off and Landing) UAV (Unmanned Aerial Vehicle). A Quad Plane is a configuration consisting of a quadcopter design combined with a conventional twin-boom airplane. This kind of design should therefore incorporate the advantages of both types of vehicles in terms of agility and long endurance. However, those benefits may come with a cost of worse performance and higher energy consumption. The characteristics of a fixed-wing aircraft and propellers in axial inflow are well documented, less attention is put to non-axial flow cases. VTOL propellers of a hybrid UAV are subject to a multitude of conditions – various inflow speeds and angles, changing RPMs, interference between propellers and between nearby aerodynamic structures. The tested system presented in this article consists of four electric motors with two coaxial pairs of propellers mounted on one of the fuselage beams. Such a configuration is often chosen by designers of small and medium hybrid UAVs. There is a need for studies of clean, efficient ways of transporting, and this article can aid future designers of a new type of electric UAVs.
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Authors and Affiliations

Katarzyna Pobikrowska
1
ORCID: ORCID
Tomasz Goetzendorf-Grabowski
1
ORCID: ORCID

  1. Institute of Aeronautics and Applied Mechanics, Warsaw University of Technology, ul. Nowowiejska 24, 00-665 Warsaw, Poland
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Abstract

It is the foundation of tunnel engineering to classify the rock mass surrounding tunnels. However, it is not easy to precisely determine the class of rock mass in practice as sufficient geological exploration need to be completed before rock mass classification, and there exists some disputes referring to the rationalization of dozens of methods for rock mass classification through the world. The principles and procedures of the basic quality method, which are widely used in China, are presented in this paper, and the application process of the basic quality method is showed with a project case of Zhongnanshan highway tunnel which has operated in safety for nearly a decade. Then, both the advantages and disadvantages of the basic quality method are analyzed in terms of practical engineering applications. In consideration of the defects of the basic quality method, the concept of the subclassing of surrounding rock in grade III–V is developed in the end and the criterion is given to determine the subclass of rock mass. This study is aimed at providing some useful ideas and a reference for rock classification in highway tunnel engineering.
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Authors and Affiliations

Du Yanqiang
1
ORCID: ORCID
Xie Bing
1
ORCID: ORCID

  1. Luoyang Institute of Science and Technology, School of Civil Engineering, No. 90 Wangcheng Avenue, Luoyang, China
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Abstract

The operating subway tunnel is often damaged due to excessive deformation in China. In order to ensure the safe for operation, remediation and protection measures must be taken, especially in soft soil areas. This paper presents a case study on remedial scheme of damaged TBM (Tunnel Boring Machine) tunnel adjacent to excavation combining with MJS (Metro Jet System) and micro-disturbance grouting technology in Hangzhou, China. The track bed settlement, horizontal displacement and convergence of the TBM tunnel caused by MJS and micro-disturbance grouting construction were analyzed and discussed. The results showed the characteristics of soil layer under the tunnel have significant influence on the treatment effect. Even if multiple grouting was adopted, the treatment failure may occur under the combination action of external loads such as traffic load or surcharge load, which should be considered when civil engineers design remediation scheme. The results can provide practical experience and guidance for similar treatment scheme of damaged TBM tunnel.
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Authors and Affiliations

Shi Feng
1
ORCID: ORCID
Yijun Yang
2
ORCID: ORCID
Yexiang Jiang
2
ORCID: ORCID
Yongdi Li
1
ORCID: ORCID
Lianghao Yao
1
ORCID: ORCID
Xiaolong Chen
1
ORCID: ORCID

  1. Chengdunsuian Underground Engineering Co., Ltd., Shanghai 201109, China
  2. Hangzhou Metro Group Co., Ltd., Hangzhou 31003, China
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Abstract

In recent years, some expressway tunnels have started broadcasting warning sounds, such as fire alarms, to improve driver attention and traffic safety. However, there is few research on it, and in contrast to previous studies, we have considered different evaluation indices and through field measurement to determine the effectiveness of this practice. The characteristics of three warning sound signals, i.e., fire alarm, dynamic music, and voice command, in a tunnel were analyzed usingMATLAB. Considering pupil diameter and blink duration as evaluation indexes, the change in the mental state of the driver after hearing a warning sound was analyzed. Based on Markov chain theory, the change in the gaze region and gaze shift of the driver under the condition of a warning sound was analyzed. Results shows fire alarms and voice commands can increase the mental load of drivers, but the degree of impact was not determined. Dynamic music does not affect the mental load of the driver. The fire alarm and dynamic music attracted the attention of the driver; conversely, as the voice command warns the driver to focus on safety, it did not impact the attention of the driver. The research results provide a scientific reference for the selection of warning sounds in expressway tunnels and new research ideas for the prevention of traffic injuries in expressway tunnels.
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Authors and Affiliations

Yao Xiao
1
ORCID: ORCID
Bo Liang
2
ORCID: ORCID
Tao Wang
3
ORCID: ORCID
Jiaan Niu
4
ORCID: ORCID
Shiyong He
2
ORCID: ORCID

  1. Chongqing Jiaotong University, School of Civil Engineering, Chongqing Rail Transit (Group) Co., Ltd, Xuefu Avenue 66, Nanan District, Chongqing, China
  2. Chongqing Jiaotong University, School of Civil Engineering, State Key Laboratory of Mountain Bridge and Tunnel Engineering, Xuefu Avenue 66, Nanan District, Chongqing, China
  3. Chongqing Industrial School, Hualongqiong, Yuzhong District, Chongqing, China
  4. Chongqing Jiaotong University, School of Civil Engineering, Xuefu Avenue 66, Nanan District, Chongqing, China
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Abstract

Idea to travel faster and faster is as old as human civilization. Different ways were used to move from point to point over centuries. The railways, cars, air-plains and rockets were invented. Each of them have limitations and advantages. Therefore, people always look for other, better solutions. One of them is “vacuum rail” moving inside a tube, known also as a Hyperloop. The number of problems to be solved is extremely high. This paper is devoted to civil engineering problems only e.g. viaducts, tunnels, stations. It is necessary to consider the kind of sub- and superstructure supporting the tube, influence of changes of ambient temperature and solar radiation, the way to ensure safety and structural integrity of the structures in case of fire, decompression of a structural tube and air-tightening, occurrence of accidents etc. Taking into account the fact that bridge and tunnel standards do not include information relating to above mentioned problems it is interesting to determine rules for design, construction and maintenance of such structures.
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Bibliography

[1] Z. Malecha, P. Krukowski, P. Pyrka, K. Skrzynecki, P. Prycinski, M. Palka, Analysis of technological rediness transportation system using high speed vehicles in limited space with reducted air preassure. Report for National research and Development Centre – Poland, 06.2018 (in Polish).
[2] M. Pawlik, M. Kycko, K. Zakrzewski, “Hyperloop vehicles spacing control challenges and possible solutions”, Archives of Civil Engineering, 2021, vol. 67, no. 2, pp. 261–274, DOI: 10.24425/ace.2021.137167.
[3] J. Piechna, Report on Conceptual Design of Hyperloop, internal material,Warsaw University of Technology, Poland, 2020 (in Polish).
[4] K. Polak, “Hyperloop technology and perspective of implementation”, Prace Instytutu Kolejnictwa, 2017, vol. 156, pp. 28–32 (in Polish).
[5] M. Rudowski, “Intermodal Transport of Hyperloop Capsules – Concept, Requirements, Benefits”, Problemy Kolejnictwa (Railway Reports), 2018, vol. 62, no. 178, pp. 55–62.
[6] R. Sabarinath, “Warsaw Hyperloop Station – Technical Challenges and Opportunities Overview”, MSc. Diploma, Warsaw University of Technology, Poland, 2020.
[7] K. Trzonski, A. Ostenda, “High speed railways – technical and social aspects – Hyperloop One”, Nowoczesne Budownictwo Inzynieryjne, 2017, no.6, pp. 86–90 (in Polish).
[8] J. Tamarit, Evacuated Tube Transportation. Sponsored by CEN/CENELEC, NEN, UNE, 12.2018.
[9] Report “Potential for the development and implementation of the vacuum rail technology in Poland in the social, technical, economic and legal context”, GOSPOSTRATEG, September 2020.
[10] Hyperloop – International Development Overview, Prepared by HARDT, HYPER POLAND, TRANSPOD, ZELEROS, 10.2018.
[11] Hyperloop Alpha by SpaceX, 2017.
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Authors and Affiliations

Henryk Zobel
1
ORCID: ORCID
Anna Pawlak
2
Marek Pawlik
3
ORCID: ORCID
Piotr Żółtowski
2
Radosław Czubacki
1
Thakaa Al-Khafaji
1
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
  2. YLE Inzynierowie Co., Warsaw, Poland
  3. Railways Institute, Warsaw, Poland
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Abstract

Tunnel construction survey must be necessary to be very quick so that the results can be known as soon as possible. This aim can be achieved through the intelligent positioning method of tunnel excavation face. In this study, the plane parameters of the tunnel cross-section were transformed into the coordinates of the points on the cross-section to realize the automatic transformation of graphic data. According to the theoretical calculation of the lofting point accuracy, the appropriate measurement control network level and measurement accuracy and the appropriate measurement instruments were selected. The fast and intelligent positioning and setting out of tunnel excavation face was realized base on the technology of data communication between computer and measuring instruments. The intelligent positioning method of tunnel excavation face could greatly reduce the time of measurement and positioning, speed up the project progress, reduce the project risk, shorten the construction period and reduce the project cost.
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Bibliography

[1] K. Rabensteiner, “Automated surveying speeds construction”, Tunnels & Tunnelling, 1996, vol. 28, no. 1, pp. 40–41.
[2] H.E. Bin, “Application of CASIO Measurement Program Assisted by Total Station in Survey of Tunnel Cross-Section”, Tunnel Construction, 2009, vol. 29, no. 1, pp. 120–122.
[3] Z. Lei, “Application of Total Station ’s Surrounding Measurement Function in Highway Survey and Design”, Peak Data Science, 2017, vol. 6, no. 4, pp. 105–107.
[4] L.F. Geng, “Analysis of mechanical properties of full section excavation of single arch four-lane highway tunnel”, Shanxi Architecture, 2009, vol. 2.
[5] Y.H. Deng, “Determination of full section excavation boundary of transition curve tunnel”, Mine Surveying, 2004, vol. 2004, no. 2, pp. 34–36.
[6] W.W. Yan, “Application of CASIO Series Programming Calculator in the Measurement of Tunnel Sections”, Shanxi ence and Technology, 2011, vol. 26, no. 4, pp. 123–124.
[7] W.B. Luo, “The realization of real-time communication between mobile intelligent equipment and total station under net environment”, Surveying and mapping equipment, 2007, vol. 9, no. 4, pp. 42–43.
[8] C.X. Niu, “Construction Survey of Tanba No. 4 Spiral Tunnel on Xiaohe-Ankang Highway”, Tunnel Construction, 2014, vol. 34, no. 2, pp. 163–166, DOI: 10.3973/j.issn.1672-741X.2014.02.013.
[9] L.H. Luo, S.L. Wei, “Application of Surveying Robot in Pipe Jacking Crossing Subway Tunnel Project”, Jiangsu Construction, 2018, vol. 2018, no. 6, pp. 65–66.
[10] W. He, C. Song, B. Du, “Chinese Longest Sea-crossing Metro Tunnel: Wuyuan Bay Station-Liuwudian Station Section of Xiamen Metro Line 3”, Tunnel Construction, 2018, vol. 38, no. 3, pp. 501–505.
[11] Y.X. Hu, Y. Yue, H.D. Zhang, et al., “Application of Gyroscope in Directional Measurement of Long Distance Cross Sea Metro Tunnel”, Urban Geotechnical Investigation & Surveying, 2019, vol. 2019, no. 6, pp. 172–175.
[12] Y. Zhou, S. Wang, M. Xi, et al., “Railway Tunnel Clearance Inspection Method Based on 3D Point Cloud from Mobile Laser Scanning”, Sensors, 2017, vol. 17, no. 9, DOI: 10.3390/s17092055.
[13] W.Wei, “3D Laser scanning technique is applied to the measurement of tunnel section deformation”, Beijing Surveying and Mapping, 2020, vol. 34, no. 4, pp. 561–565.
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Authors and Affiliations

Jiesheng Zhang
1
ORCID: ORCID
Yongzheng Qi
2
ORCID: ORCID

  1. The First Engineering Co., LTD. of CTCE Group, No. 434 Fuyang North Road, Hefei 230041, China
  2. Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, No. 2 Mengxi Road, Zhenjiang 212003, China
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Abstract

Tunnel lay-by spacing is directly related to traffic safety and engineering investment. Nevertheless, its mechanism is not clear, and the rationality of the exiting norms with respect to tunnel lay-by spacing needs to demonstrate. A calculation model for tunnel lay-by spacing was derived by considering the headway and the physical kinematics of the two vehicles chasing and encountering. With it, the influence of various parameters on lay-by spacing were analysed and the rationality of the model were discussed through comparing with existing norms. Results shows longitudinal gradient rate, daily average traffic flow, rolling resistance coefficient, posted speed limit are significant to determine the lay-by spacing, and the most important parameter is longitudinal gradient rate. Existing tunnel lay-by spacing norm values are not reasonable enough, either too strict or too loose. These findings provide scientific support for how to select tunnel lay-by spacing value, which can improve tunnel traffic safety and make engineering investment reasonable.
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Authors and Affiliations

Bo Liang
1
ORCID: ORCID
Yao Xiao
2
ORCID: ORCID

  1. Chongqing Jiaotong University, School of Civil Engineering, State Key Laboratory of Mountain Bridge and Tunnel Engineering, Xuefu Avenue 66, Nanan District, Chongqing, China
  2. Chongqing Jiaotong University, School of Civil Engineering, Chongqing Rail Transit (Group) Co., Ltd, Xuefu Avenue 66, Nanan District, Chongqing, China

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