scholarly journals Preliminary Study on the Loss Laws of Bearing Capacity of Tunnel Structure

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1951
Author(s):  
Xiao Xu ◽  
Chongbang Xu ◽  
Yang Zhang ◽  
Hualao Wang
Keyword(s):  
Bearing Capacity ◽  
Loss Rate ◽  
Mechanical Characteristics ◽  
Structural Safety ◽  
Logistic Growth ◽  
Tunnel Structure ◽  
Capacity Loss ◽  
Surrounding Environment ◽  
Relative Loss ◽  
Technical Status

The bearing capacity of the tunnel structure is the essential basis for the structural safety of tunnel engineering. Due to the unpredictability and uncertainty in the tunnel’s surrounding environment, a systematic and unambiguous study on the bearing capacity of the tunnel structure is still lacking. The analysis framework of the bearing capacity of the tunnel structure is discussed and a method describing the bearing capacity loss of the tunnel structure is proposed in this paper. Furthermore, the loss laws of the tunnel structure bearing capacity under various characteristic factors are preliminarily investigated, and suggestions on the research of bearing capacity are put forward. First, the current research contents and methods of the tunnel structure technical status, mechanical characteristics, and bearing performance (directly mentioned) are summarized, the relevant concepts related to tunnel structure bearing capacity are analyzed, and it is clarified that the bearing capacity loss of the tunnel structure can be considered according to the technical status of lining damage preliminary. Then, based on analysis of main causes and influence path of the bearing capacity loss, the influencing factors of the bearing capacity of the tunnel structure are attributed to external load action (i.e., all external causes acting on the tunnel structure in the form of external loads) and material deterioration (i.e., all internal causes leading to the decrease in mechanical properties such as structure strength/stiffness). Several typical factors are listed with specific examples, respectively. Considering the uncertainty of the absolute value of the bearing capacity caused by the surrounding environment of the tunnel, a method describing the bearing capacity of the tunnel structure using relative loss rate and relative value of index is proposed based on the current relevant analysis data of mechanical characteristics of the tunnel structure. Based on the given definitions and rules, the related data on the quantitative analysis of mechanical characteristics of lining structure reported in the literature are statistically analyzed again from the view of loss laws of the bearing capacity. Taking three factors including crack, insufficient lining thickness, and cavity as examples, the corresponding model of the bearing capacity loss is preliminarily analyzed and interpreted. The simplest linear model can be employed to preliminarily describe the relationship between defect indexes and relative loss rate of the bearing capacity, especially pertinent mechanical data collected from numerical analysis. Moreover, the loss laws of the bearing capacity in practical analysis and model tests (especially when the variation range of factors is wide) can be simulated by a logistic growth model. Through the analysis of the typical factor model, the key points of the research on the bearing capacity of the tunnel structure are discussed, and some suggestions are put forward for the follow-up related research.

Discharge-pulse Geotechnical Electro Discharge Technology of Bases Strengthening

2020 ◽  
Vol 787 (12) ◽  
pp. 63-65
Author(s):  
N.S. Sokolov
Keyword(s):  
Bearing Capacity ◽  
Mechanical Characteristics ◽  
Discharge Pulse ◽  
Zero Values ◽  
Traditional Technologies ◽  
Negative Friction ◽  
Geotechnical Problems ◽  
Physical And Mechanical Characteristics

The problem of increasing the bearing capacity of the base is an relevant problem in modern geotechnical construction. When significant loads are transmitted to the base, the use of traditional technologies is not always justified. Often there is an urgent need to use non-standard ways to strengthen the bases. In many cases, the geotechnical situation is aggravated by the presence of weak underlying layers with unstable physical and mechanical characteristics in engineering-geological sections. When strengthening such bases with the help of traditional piles, the latter can get negative friction, which significantly reduces their bearing capacity on the ground, sometimes reaching zero values. This may lead to additional precipitations of the objects being constructed and constructed in the zone of geotechnical influence. The use of ERT piles in most cases successfully solves many complex geotechnical problems.

scholarly journals Experimental and Numerical Study on Ultimate Shear Load Carrying Capacity of Corroded RC Beams

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhanzhan Tang ◽  
Zhixiang He ◽  
Zheng Chen ◽  
Lingkun Chen ◽  
Hanyang Xue ◽  
...  
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Cross Section ◽  
Loss Rate ◽  
Numerical Study ◽  
Rc Beams ◽  
Load Carrying ◽  
Shear Bearing Capacity ◽  
The Cross ◽  
The Impact

For an RC beam, the strength of steel rebar, the bonding strength between the concrete and reinforcement, and the bite action between the aggregates will deteriorate significantly due to corrosion. In the present study, 10 RC beams were designed to study the impact of corrosion on the shear bearing capacity. The mechanism of corrosion for stirrups and longitudinal bars and their effects were analyzed. Based on the existing experimental data, the correlation between the stirrup corrosion factor and the cross section loss rate was obtained. An effective prediction formula on the shear bearing capacity of the corroded RC beams was proposed and validated by the experimental results. Moreover, a numerical analysis approach based on the FE technique was proposed for the prediction of the shear strength. The results show that corrosion of the reinforcements could reduce the shear strength of the RC beams. The corrosion of stirrups can be numerically simulated by the reduction of the cross section. The formulae in the literature are conservative and the predictions are very dispersed, while the predictions by the proposed formula agree very well with the experiment results.

Mechanical characteristics of stretchable electronics based on a mogul-patterned structure

2016 ◽  
Vol 09 (06) ◽  
pp. 1642012 ◽  
Author(s):  
Yeon-Ho Lee ◽  
Youn-Jea Kim
Keyword(s):  
Flexible Electronics ◽  
Mechanical Characteristics ◽  
Mechanical Deformation ◽  
Von Mises Stress ◽  
Structural Safety ◽  
Stretchable Electronics ◽  
Film Material ◽  
Von Mises ◽  
Nanostructured Patterns ◽  
Stress And Strain Distribution

Recent progress in unconventional forms of foldable and stretchable electronics has enabled development of novel electronics. Especially, stretchable electronics have attracted much interest for applications that require reliable operation under mechanical deformation. Stretchable electrodes can be bent, stretched and compressed while maintaining good performance and structural safety. To realize flexible electronics, stretchability of devices, which requires a deeper understanding of nanoscale materials and mechanics, is needed. In this study, the mechanical characteristics of electrodes based on a mogul-pattern, which retain their electrical conductivity under mechanical deformation, were evaluated. Nanostructured patterns and thin film material were considered for stretched and bent models. The von Mises stress and strain distribution were analyzed and depicted graphically.

scholarly journals Determination of Cyclability of Li/FeS2 Batteries Based on Measurement of Coulombic Efficiency

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Paul Maldonado Nogales ◽  
Hee-Youb Song ◽  
Soon-Ki Jeong
Keyword(s):  
Loss Rate ◽  
Coulombic Efficiency ◽  
Short Term ◽  
Capacity Loss ◽  
Negative Electrodes ◽  
Short Term Test ◽  
Fading Rate ◽  
Suggested Classification

The electrochemical performance of negative electrodes based on different FeS2 samples was investigated. The study demonstrated a correlation between the coulombic efficiency obtained over 60 cycles and the capacity loss rate evaluated over 15 cycles. The accuracy of the coulombic efficiency and capacity loss rate measurements was advantageous for predicting the aging behavior of half-cells over a short-term test. A suggested classification of the coulombic efficiency and verification via a numerical analysis were proposed to determine the fading rate of batteries during the galvanostatic test.

Abnormal Structural Strength of Topocomposites

2012 ◽  
Vol 560-561 ◽  
pp. 338-343 ◽  
Author(s):  
Nikolay A. Voronin
Keyword(s):  
Surface Layer ◽  
Bearing Capacity ◽  
Half Space ◽  
Contact Interaction ◽  
Solid Body ◽  
Mechanical Characteristics ◽  
Structural Strength ◽  
Layered Material ◽  
Thin Surface Layer ◽  
Layer Coating

The mechanics of contact interaction of rigid spherical indenter with two-layer elastic - plastic half-space, simulating a surface of a solid body with a thin surface layer is considered. Analytical dependences of critical indentation and bearing capacity on mechanical characteristics of materials of a base and a coating, and as well as that for thickness of top layer (coating) in all region of possible thickness are received and analyzed. Existence of regions of the abnormal structural strength allowing the surface layered material to identify unequivocally as a topocomposite is shown. Theoretical dependences were verified by a final elements method.

Experiment Study on Mechanical Characteristics Box Girder Bridge Considering Deck Pavement

2011 ◽  
Vol 90-93 ◽  
pp. 1216-1219
Author(s):  
Yan Zeng ◽  
Guang Bin Zhang ◽  
Zhi Yong Wang
Keyword(s):  
Bearing Capacity ◽  
Work Performance ◽  
Mechanical Characteristics ◽  
Load Test ◽  
Experiment Study ◽  
Box Girder ◽  
Bonding Performance ◽  
Girder Bridge ◽  
Test Result ◽  
Actual Stress

In order to understand the mechanical characteristics of shenqiu Zhidian Bridge considering the influence of pavement, On the basis of installing steel mesh in rigid bridge or consecution to enhance the bonding performance between the pavement and girder, the load test is conducted. According to the test result and the calculations result the bearing capacity and work performance of bridge are evaluated. The results show that in the design of bridge, by enhancing the bonding performance between the pavement and girder, considering the overlaid pavement participating in force corresponds with the actual stress structure.

Model Experimental Research of Ship Section on Structural Ultimate Strength

2020 ◽  
Author(s):  
Chen Xianyin ◽  
Zeng Wenyuan ◽  
Li Cong ◽  
Wang Wei
Keyword(s):  
Bearing Capacity ◽  
Ultimate Strength ◽  
Ultimate Bearing Capacity ◽  
Ship Hull ◽  
Structural Safety ◽  
Hull Structure ◽  
Similarity Model ◽  
Large Ship ◽  
Section Structure ◽  
Classification Society

Abstract Focusing on the model design and experimental method research of ultimate strength of ship hull typical section, a large ship with complex section structure was taken in this paper as the research object. The nonlinear analysis on the failure mode and ultimate strength of the hull structure were carried out. The similarity model for ultimate strength experiment was designed, and the validity of the similarity model in reflecting the ultimate bearing capacity of the real ship was verified. According to the experimental results, the ultimate strength experimental value was obtained by numerical conversion. The ultimate bearing capacity of the example ship was then checked with reference to several classification society rules to verify the structural safety of the ship hull.

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