scholarly journals Experimental Study on Lining Cracking of Shallow Buried Loess Tunnel under the Simulation of Effect of Slide Surface Immersion

2020 ◽  
Vol 10 (17) ◽  
pp. 6080 ◽  
Author(s):  
Yuyang Liu ◽  
Hongpeng Lai
Keyword(s):  
Experimental Study ◽  
Water Immersion ◽  
Surrounding Rock ◽  
Test Results ◽  
Rock Slide ◽  
Geometric Similarity ◽  
Slide Surface ◽  
Different Types ◽  
Similarity Ratio ◽  
Secondary Lining

The water immersion of surrounding rock slide surface causes lining cracking of the shallow buried loess tunnel, and different types of slide surface and different immersion degrees have different effects on secondary lining. In this paper, four types of slide surfaces for shallow buried loess tunnel are proposed. In order to find out the characteristics and laws of lining cracking under the effect of slide surface immersion, a loading model test with a large geometric similarity ratio of 1:10 was carried out. The test results show that the immersion of the slide surface has the most significant influence on the deformation of the lining vault and the arch waist, and the value and speed of the vault deformation are always the largest. When the unilateral slide surface is immersed in water, the lining cracking is concentrated on the flooded side of the slide surface, and the appearance of compressive cracks can be regarded as a precursor of lining instability. In the direction of lining thickness, the cracks always begin to develop from I-type, then gradually develop into L-type, and finally develop to Y-type, among which the number of L-type cracks is the most. Furthermore, the residual bearing capacity of cracked lining is also discussed.

Experimental Study on Seismic Behavior of Strengthening Joints in Light Steel Adding Storey

2013 ◽  
Vol 671-674 ◽  
pp. 1480-1483
Author(s):  
Rong Guo ◽  
Shao Wei Zhao ◽  
Kun Liu
Keyword(s):  
Experimental Study ◽  
Energy Consumption ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Stiffness Degradation ◽  
Test Results ◽  
Static Tests ◽  
Concrete Frame ◽  
Different Types ◽  
Strengthening Method

In order to acquire the seismic performance of three different types of nodes between the concrete frame and the light steel adding storey, the pseudo-static tests were carried out to analyse contrastively these specimens’ failure modes, stiffness degradation, hysteretic curves and energy dissipation. The test results showed that : Three nodes’ destruction were due to the plastic hinges emerging at the end of beam; both encased steel and carbon fiber strengthening method can improve the seismic behavior, and in terms of the ultimate bearing capacity, energy consumption ability，the encased steel strengthening one can improved more significantly, and the encased steel one can effectively slow down the speed of stiffness degradation.

Experimental Study on Preparing Ecological Building Mortar by Using Solid Waste

2013 ◽  
Vol 763 ◽  
pp. 199-202
Author(s):  
Chao Yong Yan ◽  
Zhi Hua Li ◽  
Xiao Min Deng
Keyword(s):  
Adverse Effect ◽  
Experimental Study ◽  
Compressive Strength ◽  
Water Consumption ◽  
Cementitious Materials ◽  
Test Results ◽  
Natural Sand ◽  
Brick Powder ◽  
Different Types ◽  
Ecological Building

This paper presents a kind of ecological building mortar with a compressive strength of M5.0, M7.5 and M10 , which includes waste residue as cementitious materials, and waste brick powder, waste mortar powder reclaimed sand instead of natural sand as aggregate. The test results shows that (1) mortar water consumption increase when recycled sand volume increases, but its water-retaining capacity goes up;(2) when different types of recycled sand are used instead of natural sand for middle and low strength mortar, there is no significant adverse effect on its strength, and the 28d compressive strength can all meet the designed strength requirements; (3) Little difference exists among the influence of different recycled sand on properties of mortar.

Study on Gas Anti-Permeability of Fiber Concrete under Fatigue Loading

2011 ◽  
Vol 243-249 ◽  
pp. 793-796
Author(s):  
Qing Yu Cao ◽  
Wei Sun ◽  
Li Ping Guo
Keyword(s):  
Gas Permeability ◽  
Fatigue Loading ◽  
Surrounding Rock ◽  
Test Results ◽  
Curing Conditions ◽  
Fiber Concrete ◽  
Result Show ◽  
Surrounding Rock Pressure ◽  
Secondary Lining ◽  
Fine Organic

Cracking is the most common damage in the secondary lining concrete because of its continuous thin-walled structure, potential surrounding rock pressure and poor curing conditions. In order to improve the fatigue and gas perimeability resistance of concrete and to reduce the responding costs, four series modern concretes including ultra-fine pozzolanic powder and organic fibers are prepared and investigated. The optimized modern secondary lining concrete is determined as the concrete including 0.08% or 0.1% volume fractions of ultra-fine organic fiber (UF), based on the test results of fatigue life and coefficient of gas-permeability under fatigue loading. The result show fiber concrete is positive for enhancing the fatigue and gas permeability resistance and can apply for the tunnel secondary lining.

scholarly journals A New Fibre Composite Beam for Civil Engineering Applications

1999 ◽  
Vol 8 (5) ◽  
pp. 096369359900800
Author(s):  
Gerard M. Van Erp
Keyword(s):  
Experimental Study ◽  
Composite Beam ◽  
Civil Engineering ◽  
Concrete Beams ◽  
Fibre Composite ◽  
Test Results ◽  
Structural Behaviour ◽  
Resin Core ◽  
Different Types ◽  
Very High

This paper presents preliminary findings of an experimental study into the structural behaviour of a new composite beam designed specifically for the civil engineering market. The Filled Resin Core (FRC) beam eliminates most problems associated with standard pultruded beams and is capable of carrying very high loads at a cost similar to steel and concrete beams. Principles of the new design are discussed and test results for three different types of beams are presented.

Internal stresses in glulam due to moisture gradients in the grain direction

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Johan Hans Jönsson
Keyword(s):  
Climate Change ◽  
Experimental Study ◽  
Stress State ◽  
Modulus Of Elasticity ◽  
Internal Stresses ◽  
Test Results ◽  
Tensile Stresses ◽  
Glued Laminated Timber ◽  
Average Maximum ◽  
Different Types

Abstract An experimental study on the internal stress state perpendicular to grain in glued laminated timber induced by moisture variations along the grain is presented. The stress is evaluated by using measured modulus of elasticity and strain. Different types of tests are performed, in which specimens are exposed to artificial climate change when the specimens are in either a wetting or a drying state, and specimens are exposed to a cyclic climate change. Test results from the specimens that were in a drying state show that the tensile stresses near the end of the specimens at some point exceeds the strength of the wood and cracks. In the opposite test, when the specimens are in a moistening phase, the maximum tensile stresses are lower and in the order of 0.2 MPa during the tested period. The cyclic test, which continued during 20 weeks, showed that there were no accumulated effects regarding strain and stress values. In this test, the average maximum tensile and compression stresses were of the order 0.20 and 0.10 MPa, respectively.

scholarly journals Investigation of Moisture Management and Air Permeability Properties of Fabrics with Linen and Linen-Polyester Blend Yarns

2018 ◽  
Vol 26 (4(130)) ◽  
pp. 39-47 ◽  
Author(s):  
Erhan Kenan Çeven ◽  
Gizem Karakan Günaydin
Keyword(s):  
Experimental Study ◽  
Absorption Rate ◽  
Structural Parameters ◽  
Air Permeability ◽  
Test Results ◽  
Warp Yarn ◽  
Significance Level ◽  
Moisture Management ◽  
Different Types ◽  
Wetting Time

This paper has focused on moisture management (MMT) and air permeability properties of fabrics produced from linen (100%) and linen-polyester yarns (80% polyester and 20% linen) at different weft densities. In the experimental study, eighteen different types of fabrics composed of six different weft yarns with three levels of weft density (weft density of 8,10 &12 pick/cm for 100% linen fabrics and 14,16,18 pick/cm for polyester-linen fabrics) were selected in order to determine the influence of weft density and yarn structural parameters (number of yarn folds) on moisture management as well as air permeability properties. The following weft yarns were selected: 104/1 tex, 104/2 tex & 104/3 tex for 100% linen and 41/1 tex, 41/2 tex & 41/3 tex for 80% Polyester – 20% linen fabrics, whereas the warp yarn was constant – 50/1 tex 100% linen for all fabric types. Satin type fabrics were subjected to moisture management tests and air permeability tests as well. According to test results, it was determined that some of the moisture management (wetting time, absorption rate (%/s) and one-way accumulative transport index of the fabrics’ top surfaces and bottom surfaces) and air permeability properties were significantly affected by the number of yarn folds and the weft density at a 0.05 significance level.

The influence of information relevance on the continued influence effect of misinformation

2020 ◽  
Author(s):  
Hua Jin ◽  
Lina Jia ◽  
Xiaojuan Yin ◽  
Shilin Wei ◽  
Guiping Xu
Keyword(s):  
Experimental Study ◽  
Questionnaire Survey ◽  
Personal Involvement ◽  
Influence Effect ◽  
Information Relevance ◽  
Different Types ◽  
Role Of Information

Misinformation often continues to influence people’s cognition even after corrected (the ‘continued influence effect of misinformation’, the CIEM). This study investigated the role of information relevance in the CIEM by questionnaire survey and experimental study. The results showed that information with higher relevance to the individuals had a larger CIEM, indicating a role of information relevance in the CIEM. Personal involvement might explain the effects of information relevance on the CIEM. This study provides insightful clues for reducing the CIEM in different types of misinformation and misinformation with varying relevance.

scholarly journals About the Acceptance of Wearing Face Masks in Times of a Pandemic

i-Perception ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 204166952110211
Author(s):  
Claus-Christian Carbon
Keyword(s):  
Experimental Study ◽  
Social Group ◽  
Social Norm ◽  
Face Mask ◽  
Negative Consequences ◽  
Different Types ◽  
Study Participants

Wearing face masks in times of COVID-19 is one of the essential keystones for effectively decreasing the rate of new infections and thus for mitigating the negative consequences for individuals as well as for society. Acceptance of wearing masks is still low in many countries, making it extremely difficult to keep the pandemic at bay. In an experimental study, participants ( N = 88) had to assess how strange they felt when wearing a face mask while being exposed to displays of groups of varying numbers of mask wearers. Three different types of face masks were shown: simple homemade masks, FFP2 masks, and loop scarfs. The higher the frequency of people wearing masks in the displayed social group, the less strange the participants felt about themselves, an essential precondition for accepting wearing masks. This effect of a descriptive social norm was particularly effective when people saw others wearing less intrusive masks, here, simple homemade masks.

Effects of ball properties on throwing in young team-handball beginners

2021 ◽  
pp. 174795412110236
Author(s):  
Frowin Fasold ◽  
Benjamin Noël ◽  
André Nicklas ◽  
Fabian Lukac ◽  
Stefanie Klatt
Keyword(s):  
Experimental Study ◽  
Movement Patterns ◽  
Team Handball ◽  
Throwing Accuracy ◽  
Different Types ◽  
Negative Effect ◽  
Study Participants

Throwing a ball is a primary skill in team-handball and can be directly influenced by the properties of different types of balls. Therefore, the use of different balls (i.e., methodic ball) recommended by the handball federations (e.g., IHF) and the education guidelines, are important in teaching throwing. Previous studies have shown that movement patterns and throwing velocity can be influenced by different ball types and sizes. However, the influence of these factors on throwing accuracy has not been investigated in detail yet. This study aims to replicate the findings of previous studies on increasing throwing velocity in children by comparing the use of a soft methodic ball with a size 0 handball. Furthermore, this study investigates the influence of these balls on throwing accuracy. In an experimental study, participants (10-years of age) threw a soft methodic ball and a size 0 ball at target areas in a handball goal. For all the throws, throwing velocity and accuracy were measured. Commensurate with previous research, throwing velocity was higher for the soft methodic ball compared to a size 0 ball. No difference was found in accuracy, although, it is worth mentioning that the participants were only experienced in throwing using the size 0 ball. Moreover, only one-third of the children favored throwing with a size 0 ball, which is what they are used to in training and competition. The results of our study, therefore, confirm that using soft methodic balls additionally, positively influences the throwing velocity and has no negative effect on the accuracy in throwing among young handball beginners.

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