Symmetry in Civil Transportation Engineering

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Engineering and Materials".

Deadline for manuscript submissions: 31 July 2024 | Viewed by 4158

Special Issue Editors

School of Mechanics and Civil Engineering , China University of Mining and Technology-Beijing, Beijing 100083, China
Interests: rock mechanics; soil mechanics; geomechanics; engineering geology

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Guest Editor
School of Mechanics and Civil Engineering, China University of Mining and Technology-Beijing, Beijing 100083, China
Interests: civil engineering; engineering mechanics; engineering geology; earth sciences; energy; environmental science

Special Issue Information

Dear Colleagues,

Symmetrical structures have become common in civil transportation engineering, such as in buildings and their components (high-rise buildings, airports, bridges, piers, and foundations), tunnels, subway stations, retaining walls, roadbeds, etc. Research on the stability, vulnerability, durability, and other issues of these symmetrical structures or buildings plays an important role in the civil and transportation fields. In the process of underground space construction, many excavation methods also have symmetry, such as the bench cut method, circular excavation with the core soil method, and the double-side-wall heading excavation method. The supporting structures used are also symmetrical, such as the anchor rod design, lining structures, support systems, underground structures, etc. After excavation, the deformation and stress distribution of the surrounding rock surface settlement are symmetrical. The crack propagation mode of rock containing flaws caused by excavation unloading is symmetrical or has central symmetry, and the deformation and stress distribution of maintenance structures and underground structures are also symmetrical. Therefore, this symmetry is widely present in civil and transportation engineering. How to develop and utilize symmetrical structures, symmetrical excavation methods, and symmetrical support forms is of great significance for the development of engineering construction in this field. At the same time, how to effectively control such symmetrical deformation and settlement is of great significance for disaster prevention and reduction.

Dr. Yao Bai
Prof. Dr. Renliang Shan
Guest Editors

Manuscript Submission Information

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Keywords

  • new building structural systems
  • excavation and support of large cross-section tunnels
  • PBA construction method
  • surrounding rock–support interaction
  • surface settlement during tunnel excavation
  • new technologies for geotechnical testing
  • mechanical properties of frozen rock and soil
  • environmental geotechnical engineering

Published Papers (4 papers)

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Research

21 pages, 9998 KiB  
Article
Under Sulfate Dry–Wet Cycling: Exploring the Symmetry of the Mechanical Performance Trend and Grey Prediction of Lightweight Aggregate Concrete with Silica Powder Content
by Hailong Wang, Yaolu Chen and Hongshan Wang
Symmetry 2024, 16(3), 275; https://doi.org/10.3390/sym16030275 - 26 Feb 2024
Viewed by 829
Abstract
In order to improve the mechanical properties and durability of lightweight aggregate concrete in extreme environments, this study utilized Inner Mongolia pumice as the coarse aggregate to formulate pumice lightweight aggregate concrete (P-LWAC) with a silica powder content of 0%, 2%, 4%, 6%, [...] Read more.
In order to improve the mechanical properties and durability of lightweight aggregate concrete in extreme environments, this study utilized Inner Mongolia pumice as the coarse aggregate to formulate pumice lightweight aggregate concrete (P-LWAC) with a silica powder content of 0%, 2%, 4%, 6%, 8%, and 10%. Under sulfate dry–wet cycling conditions, this study mainly conducted a mass loss rate test, compressive strength test, NMR test, and SEM test to investigate the improvement effect of silica powder content on the corrosion resistance performance of P-LWAC. In addition, using grey prediction theory, the relationship between pore characteristic parameters and compressive strength was elucidated, and a grey prediction model GM (1,3) was established to predict the compressive strength of P-LWAC after cycling. Research indicates that under sulfate corrosion conditions, as the cycle times and silica powder content increased, the corrosion resistance of P-LWAC showed a trend of first increasing and then decreasing. At 60 cycles, P-LWAC with a content of 6% exhibited the lowest mass loss rate and the highest relative dynamic elastic modulus, compressive strength, and corrosion resistance coefficient. From the perspective of data distribution, various durability indicators showed a clear mirror symmetry towards both sides with a silica powder content of 6% as the symmetrical center. The addition of silica fume reduced the porosity and permeability of P-LWAC, enhanced the saturation degree of bound fluid, and facilitated internal structural development from harmful pores towards less harmful and harmless pores, a feature most prominent at the 6% silica fume mixing ratio. In addition, a bound fluid saturation and pore size of 0.02~0.05 μm/% exerted the most significant influence on the compressive strength of P-LWAC subjected to 90 dry–wet cycles. Based on these two factors, grey prediction model GM (1,3) was established. This model can accurately evaluate the durability of P-LWAC, improving the efficiency of curing decision-making and construction of concrete materials. Full article
(This article belongs to the Special Issue Symmetry in Civil Transportation Engineering)
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18 pages, 7128 KiB  
Article
Analysis of Vibration Responses Induced by Metro Operations Using a Probabilistic Method
by Zongzhen Wu, Chunyang Li, Weifeng Liu, Donghai Li, Wenbin Wang and Bin Zhu
Symmetry 2024, 16(2), 145; https://doi.org/10.3390/sym16020145 - 26 Jan 2024
Viewed by 703
Abstract
The environmental vibrations of tunnels and soil caused by metro operations is one of the most important issues in the field of environmental geotechnical engineering. Recent studies in metro-induced vibrations have revealed significant uncertainties in the vibration responses of tunnels and the surrounding [...] Read more.
The environmental vibrations of tunnels and soil caused by metro operations is one of the most important issues in the field of environmental geotechnical engineering. Recent studies in metro-induced vibrations have revealed significant uncertainties in the vibration responses of tunnels and the surrounding soil. A two-step method of obtaining train loads considering uncertainty was introduced. The first step was to obtain the train loads via an inverse model based on measurements, and the second step was to quantify the uncertainty of train loads based on complex principal component analysis. A portion of a tunnel of the Beijing metro was selected as the object of study, where the vertical accelerations on the rail and on the tunnel wall were measured under different train speeds of 35, 45 and 55 km/h. Inputting the train loads based on the measured rail accelerations into an axisymmetric numerical model, established using ANSYS, the vibration responses of the tunnel wall in a probabilistic framework were calculated and were compared with the measured results. By using an accuracy index that considers both calculation bias and uncertainty, the accuracy of the calculated vibration response was quantitatively evaluated. It can be concluded that the calculated vibration response can reflect the actual vibration level and uncertainty of the tunnel wall. The accuracies of the calculated results under different speeds were generally high while showing a slight difference in amplitude. Full article
(This article belongs to the Special Issue Symmetry in Civil Transportation Engineering)
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28 pages, 19285 KiB  
Article
Solving Conformal Mapping Issues in Tunnel Engineering
by Wenbo Chen, Dingli Zhang, Qian Fang, Xuanhao Chen and Lin Yu
Symmetry 2024, 16(1), 86; https://doi.org/10.3390/sym16010086 - 10 Jan 2024
Cited by 1 | Viewed by 1101
Abstract
The calculation of conformal mapping for irregular domains is a crucial step in deriving analytical and semi-analytical solutions for irregularly shaped tunnels in rock masses using complex theory. The optimization methods, iteration methods, and the extended Melentiev’s method have been developed and adopted [...] Read more.
The calculation of conformal mapping for irregular domains is a crucial step in deriving analytical and semi-analytical solutions for irregularly shaped tunnels in rock masses using complex theory. The optimization methods, iteration methods, and the extended Melentiev’s method have been developed and adopted to calculate the conformal mapping function in tunnel engineering. According to the strict definition and theorems of conformal mapping, it is proven that these three methods only map boundaries and do not guarantee the mapping’s conformal properties due to inherent limitations. Notably, there are other challenges in applying conformal mapping to tunnel engineering. To tackle these issues, a practical procedure is proposed for the conformal mapping of common tunnels in rock masses. The procedure is based on the extended SC transformation formulas and corresponding numerical methods. The discretization codes for polygonal, multi-arc, smooth curve, and mixed boundaries are programmed and embedded into the procedure, catering to both simply and multiply connected domains. Six cases of conformal mapping for typical tunnel cross sections, including rectangular tunnels, multi-arc tunnels, horseshoe-shaped tunnels, and symmetric and asymmetric multiple tunnels at depth, are performed and illustrated. Furthermore, this article also illustrates the use of the conformal mapping method for shallow tunnels, which aligns with the symmetry principle of conformal mapping. Finally, the discussion highlights the use of an explicit power function as an approximation method for symmetric tunnels, outlining its key points. Full article
(This article belongs to the Special Issue Symmetry in Civil Transportation Engineering)
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18 pages, 9436 KiB  
Article
A Study of Anchor Cable and C-Shaped Tube Support for the Roadway of Shuangliu Coal Mine
by Li Li, Xiang-Song Kong, Wei Yang, Jun-Wei Huang and Zhi-En Wang
Symmetry 2023, 15(9), 1757; https://doi.org/10.3390/sym15091757 - 13 Sep 2023
Cited by 2 | Viewed by 839
Abstract
Active support using highly prestressed cable bolts and anchor cables has become a mainstream support technology for coal mine roadways. However, the ability of bolts and anchor cables to withstand transverse shear decreases with the prestress level, jeopardizing mining safety. This study proposed [...] Read more.
Active support using highly prestressed cable bolts and anchor cables has become a mainstream support technology for coal mine roadways. However, the ability of bolts and anchor cables to withstand transverse shear decreases with the prestress level, jeopardizing mining safety. This study proposed a technical solution to this problem featuring anchor cables enclosed in an axisymmetrical tube with a C-shaped cross-section (ACC), which are highly prestressed and can withstand high transverse shear. The ACC mechanical performance was tested in the #318 gas extraction roadway of the Shuangliu Coal Mine, China, characterized by extensive deformation under original support conditions. Theoretical analysis, laboratory tests, numerical simulation, and field tests were performed to analyze the shear mechanical properties of the ACC and anchor cables alone. The double shear test results revealed that the proposed ACC scheme increased the transverse shear resistance and stiffness by 10–25% and 20–40%, respectively. The FLAC3D numerical simulation showed that the roof-and-floor and rib-to-rib convergences decreased by 9.53 and 25.11%, respectively. The area of the stress concentration zone also decreased. Field monitoring showed that the ACC achieved good support performance. During the monitoring period, the maximum roof-and-floor and rib-to-rib displacements were 40 and 49 mm, respectively. The ACC scheme offered adequate shear resistance and effectively controlled surrounding rock deformation in the gas extraction roadway under study, making it applicable to similar engineering scenarios. Full article
(This article belongs to the Special Issue Symmetry in Civil Transportation Engineering)
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