scholarly journals Experimental Study of Split Grouting Reinforcement Mechanism in Filling Medium and Effect Evaluation

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3088
Author(s):  
Jiandong Niu ◽  
Zewei Li ◽  
Weiheng Gu ◽  
Kang Chen
Keyword(s):  
Dynamic Contact ◽  
Friction Angle ◽  
Test System ◽  
Uniaxial Compression Test ◽  
Contact Test ◽  
Reinforcement Mechanism ◽  
Information Monitoring ◽  
Before And After ◽  
Grouting Reinforcement ◽  
The Relationship

In view of the deficiency of the split grouting theory for the filling area, a 3D simulated grouting test system was designed to explore the slurry diffusion law, reinforcement mechanism of split grouting in a filling soil, and effect of grouting reinforcement. The test system included an experiment bench system, grouting system, and information monitoring system, using which experimental research on split grouting in a filling soil was conducted. The grouting model experiment procedure was introduced first, following which the diffusion rule of slurry in the filling medium and the reinforcement mechanism of split grouting were analyzed according to the properties and distribution characteristics of grouting veins after grouting reinforcement. Finally, a uniaxial compression test, light dynamic contact test, permeability test, and laboratory geotechnical test were conducted on the soil before and after grouting. The relationship between the zoning characteristics of different properties of veins and the mechanical properties of filling soil were discussed. The results showed that there were three types of grouting veins: trunk grouting, branch grouting, and permeable grouting. The injected soil body was strengthened by the three-stage grouting vein network of the mentioned vein types and the compaction between soils. After the grouting, the uniaxial compressive strength of the filling soil increased by an average of 186%, and the permeability coefficient decreased by an average of 47 times. The cohesion and internal friction angle increased by 45.3% and 44.9%, respectively. Additionally, density, water content, and other indicators of filling were improved. The bearing characteristics reflected by a dynamic contact test were consistent with the distribution of grouting veins. The research results offer significant guidance for the reinforcement mechanism of split grouting and the evaluation of the grouting effect.

scholarly journals Experimental Study on the Reinforcement Mechanism of Segmented Split Grouting in a Soft Filling Medium

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 131 ◽  
Author(s):  
Zhipeng Li ◽  
Shucai Li ◽  
Haojie Liu ◽  
Qingsong Zhang ◽  
Yanan Liu
Keyword(s):  
Elastic Modulus ◽  
Permeability Coefficient ◽  
Three Dimensional ◽  
Weighted Average ◽  
Quantitative Relationship ◽  
Uniaxial Compression Test ◽  
Distribution Characteristics ◽  
Reinforcement Mechanism ◽  
Before And After ◽  
Grouting Reinforcement

Subsection split grouting technology can effectively improve the grouting efficiency and homogeneity of grouting in a target reinforcement area. It is therefore necessary to clarify the reinforcement mechanism and characteristics of the soft filling medium under the condition of split grouting. A three-dimensional grouting simulation test of segmented split grouting in a soft filling medium was conducted. The distribution characteristics and thicknesses of the grouting veins were obtained under the condition of segmented grouting. The mechanical mechanism of segmented split grouting reinforcement, based on the distribution characteristics of different grouting veins, was revealed. After grouting, a uniaxial compression test and an indoor permeation test were conducted. Based on the method of the region-weighted average, the corresponding permeability coefficient and the elastic modulus of each splitting-compaction region were obtained. The quantitative relationship between the mechanical properties and the impermeability of the soft filling medium before and after grouting was established. The results revealed that three different types of veins were formed as the distance from the grouting holes increased; namely, skeleton veins, cross-grid grouting veins, and parallel dispersed grouting veins. The thicknesses of the grouting veins decreased gradually, whereas the number of grouting veins increased. Moreover, the strikes of the grouting vein exhibited increased randomness. The reinforcement effect of segmental split grouting on soft filling media was mainly confirmed by the skeleton support and compaction. The elastic modulus of the grouting reinforcement solid increased on average by a factor that was greater than 100, and the permeability coefficient decreased on average by a factor that was greater than 40 in the direction of the parallel grouting vein with the most impermeable solid. The research results may be helpful in the investigation of the split grouting reinforcement mechanism under the condition of segmented grouting.

scholarly journals Effect analysis of grouting reinforcement ring considering fluid solid coupling

2019 ◽  
Vol 277 ◽  
pp. 03014
Author(s):  
Heng Zhou ◽  
Xiaochen Wang ◽  
Haojie Liu ◽  
Yanan Liu ◽  
Chenyang Ma ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Physical Parameters ◽  
Sand Layer ◽  
Effect Analysis ◽  
Reinforcement Ring ◽  
Before And After ◽  
Grouting Reinforcement ◽  
Set Up ◽  
Subway Tunnels ◽  
The Relationship

Geological hazards such as instability of surrounding rock and leakage of water are easily occurred in subway tunnels crossing water rich sand layers. Based on the principle of fluid solid coupling in porous media, this paper studies the plastic zone distribution of surrounding rock and reinforcement ring, vertical settlement of tunnel vault and water seepage of tunnel before and after grouting reinforcement for water rich sand layer. Considering the compressibility of rock mass, the relationship between porosity, permeability and volume strain is further deduced and simplified. A set of numerical calculation formula is set up to study the change of physical parameters of the water rich sand layer before and after grouting to determine the grouting effect and select the thickness of the best grouting reinforcement ring. The results show that the deformation and water permeability of the tunnel decrease with the increase of the thickness of the grouting reinforcement ring. The thickness of the grouting reinforcement ring is the most reasonable when the thickness of the reinforcing ring reaches a certain value, and the thickness of the grouting reinforcement ring is designed to be 5~6m. The research results have been successfully applied in the grouting project of Qingdao Metro stone elderly bathing beach. The reliability of the numerical simulation is verified by comparing the data from the field monitoring and measurement, providing reference for the related projects.

Enhancing Spatial Ability Through Sport Practice

2012 ◽  
Vol 33 (2) ◽  
pp. 83-88 ◽  
Author(s):  
David Moreau ◽  
Jérome Clerc ◽  
Annie Mansy-Dannay ◽  
Alain Guerrien
Keyword(s):  
Mental Rotation ◽  
Spatial Representations ◽  
Mental Rotation Test ◽  
Sport Training ◽  
Sport Practice ◽  
Undergraduate University Students ◽  
Before And After ◽  
Cognitive Plasticity ◽  
Reported Data ◽  
The Relationship

This experiment investigated the relationship between mental rotation and sport training. Undergraduate university students (n = 62) completed the Mental Rotation Test ( Vandenberg & Kuse, 1978 ), before and after a 10-month training in two different sports, which either involved extensive mental rotation ability (wrestling group) or did not (running group). Both groups showed comparable results in the pretest, but the wrestling group outperformed the running group in the posttest. As expected from previous studies, males outperformed women in the pretest and the posttest. Besides, self-reported data gathered after both sessions indicated an increase in adaptive strategies following training in wrestling, but not subsequent to training in running. These findings demonstrate the significant effect of training in particular sports on mental rotation performance, thus showing consistency with the notion of cognitive plasticity induced from motor training involving manipulation of spatial representations. They are discussed within an embodied cognition framework.

Klein with Lacan: A Study on the Reception of Lacanian Ideas in Uruguay and Its Effects on Clinical Practices (1955–82)

2020 ◽  
Vol 22 (3) ◽  
pp. 341-361
Author(s):  
Gonzalo Grau-Pérez ◽  
J. Guillermo Milán
Keyword(s):  
Clinical Practice ◽  
Clinical Material ◽  
Clinical Practices ◽  
Before And After ◽  
The Difference ◽  
The 1960S ◽  
The Relationship ◽  
Discursive Approach ◽  
The Way ◽  
Clinical Cases

In Uruguay, Lacanian ideas arrived in the 1960s, into a context of Kleinian hegemony. Adopting a discursive approach, this study researched the initial reception of these ideas and its effects on clinical practices. We gathered a corpus of discursive data from clinical cases and theoretical-doctrinal articles (from the 1960s, 1970s and 1980s). In order to examine the effects of Lacanian ideas, we analysed the difference in the way of interpreting the clinical material before and after Lacan's reception. The results of this research illuminate some epistemological problems of psychoanalysis, especially the relationship between theory and clinical practice.

STUDY ON THE RELATIONSHIP BETWEEN PARASITIC INFECTION AND KNOWLEDGE, HYGIENIC PRACTICAL MEASURES OF PARASITIC INFECTIOUS PREVENTION IN VINH THAI COMMUNITY

2017 ◽  
pp. 119-124
Author(s):  
Keyword(s):  
Health Education ◽  
Risk Behaviors ◽  
Ascaris Lumbricoides ◽  
Intestinal Parasite ◽  
Parasitic Infection ◽  
Parasite Infection ◽  
Intestinal Parasite Infection ◽  
Before And After ◽  
Parasite Infections ◽  
The Relationship

Introduction: Intestinal parasite infections werecommonintropical country such as Vietnam. Having good knowledge of parasitic infectious prevention and changing risk behaviors can decrease the infection rate. Objective: To evaluate the parasitic infectious rate in Vinh Thai community before and after being health education and the changing of knowledge of parasitic infectious prevention and risk behaviors. Materials and methods: 60 households in Vinh Thai commune were interviewed their knowledge of parasitic infectious prevention and examined intestinal parasite infection by Kato technique and then trained the knowledge of parasitic infectious prevention. The interview and examination parasite infectiousrate were carried out after 6 months to evaluating their knowledge. Result: Before health education, the rate of intestinal parasite infection was 17.4% with the prevalence of Ascaris lumbricoides, hookworm, whipworm, pinworm, small fluke worm and co-infection with A. lumbricoides - whipworm, hookworm-whipworm were 0.1%; 8.0%; 5.8%; 0.6%; 0.3%; 1.2% and 3.0% respectively. Six months later the rate of intestinal parasite infection was decreased in 12.6% even though not statistical significantly. However, there were no case of small fluke worm and co-infection with hookworm-whipworm. Receiving health education, their knowledge of parasitic infectious prevention was higher significantly but their risk behaviors were not changed so much. Conclusion: Health education can change the rate of parasite infection with higher knowledge of parasitic infectious prevention but it was necessary continuous study to change the risk behaviors. Key words: intestinal parasite, health education

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

APPLICATION OF THE ATP-BIOLUMINESCENCE METHOD TO ASSESS THE QUALITY OF SANITATION OF MILKING EQUIPMENT

2020 ◽  
Vol 1 (4) ◽  
pp. 468-472
Author(s):  
P.A. Popov ◽  
◽  
D.V. Gruznov ◽  
S.V. Tokarev ◽  
◽  
...  
Keyword(s):  
Dairy Farms ◽  
Laboratory Studies ◽  
Before And After ◽  
Atp Bioluminescence ◽  
Microbial Number ◽  
Proportional Relationship ◽  
The Relationship ◽  
Number Of Bacteria ◽  
Bioluminescence Method

The article presents the results of determining the relationship between the total microbial number and microbial ATP on the surface of milking equipment before and after treatment with neutral anolyte ANK-SUPER. The possibility of using the ATP-bioluminescence method to control the quality of sanitation of milking equipment on dairy farms is shown. Laboratory studies revealed a proportional relationship between the level of bacterial ATP and the number of bacteria on the surface of milking equipment before and after sanitation.

scholarly journals Post-Drive Standing Balance of Vehicle Passengers Using Wearable Sensors: The Effect of On-Road Driving and Task Performance

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4997
Author(s):  
Victor C. Le ◽  
Monica L. H. Jones ◽  
Kathleen H. Sienko
Keyword(s):  
Task Performance ◽  
Postural Sway ◽  
Wearable Sensors ◽  
Standing Balance ◽  
Balance Performance ◽  
Real Time Traffic ◽  
Balance Exercises ◽  
Before And After ◽  
The Relationship ◽  
And Task

Postural sway has been demonstrated to increase following exposure to different types of motion. However, limited prior studies have investigated the relationship between exposure to normative on-road driving conditions and standing balance following the exposure. The purpose of this on-road study was to quantify the effect of vehicle motion and task performance on passengers’ post-drive standing balance performance. In this study, trunk-based kinematic data were captured while participants performed a series of balance exercises before and after an on-road driving session in real-time traffic. Postural sway for all balance exercises increased following the driving session. Performing a series of ecologically relevant visual-based tasks led to increases in most post-drive balance metrics such as sway position and velocity. However, the post-drive changes following the driving session with a task were not significantly different compared to changes observed following the driving session without a task. The post-drive standing balance performance changes observed in this study may increase vulnerable users’ risk of falling. Wearable sensors offer an opportunity to monitor postural sway following in-vehicle exposures.

scholarly journals Correlation between Uniaxial Compression Test and Ultrasonic Pulse Rate in Cement with Different Pozzolanic Additions

2021 ◽  
Vol 11 (9) ◽  
pp. 3747
Author(s):  
Leticia Presa ◽  
Jorge L. Costafreda ◽  
Domingo Alfonso Martín
Keyword(s):  
Compression Test ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Uniaxial Compression Test ◽  
Unconfined Compression Test ◽  
Pozzolanic Cement ◽  
The Relationship ◽  
Compression Resistance

This work aims to study the relationship between the compression resistance and velocity from ultrasonic pulses in samples of mortars with 25% of pozzolanic content. Pozzolanic cement is a low-priced sustainable material that can reduce costs and CO2 emissions that are produced in the manufacturing of cement from the calcination of calcium carbonate. Using ultrasonic pulse velocity (UPV) to estimate the compressive resistance of mortars with pozzolanic content reduces costs when evaluating the quality of structures built with this material since it is not required to perform an unconfined compression test. The objective of this study is to establish a correlation in order to estimate the compression resistance of this material from its ultrasonic pulse velocity. For this purpose, we studied a total of 16 cement samples, including those with additions of pozzolanic content with different compositions and a sample without any additions. The results obtained show the mentioned correlation, which establishes a basis for research with a higher number of samples to ascertain if it holds true at greater curing ages.

scholarly journals Reduction in mobility and COVID-19 transmission

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pierre Nouvellet ◽  
Sangeeta Bhatia ◽  
Anne Cori ◽  
Kylie E. C. Ainslie ◽  
Marc Baguelin ◽  
...  
Keyword(s):  
Predictive Ability ◽  
Control Measures ◽  
Social Distancing ◽  
Beneficial Effects ◽  
Mobility Data ◽  
Strict Control ◽  
Before And After ◽  
Proxy Measure ◽  
Lower Transmission ◽  
The Relationship

AbstractIn response to the COVID-19 pandemic, countries have sought to control SARS-CoV-2 transmission by restricting population movement through social distancing interventions, thus reducing the number of contacts. Mobility data represent an important proxy measure of social distancing, and here, we characterise the relationship between transmission and mobility for 52 countries around the world. Transmission significantly decreased with the initial reduction in mobility in 73% of the countries analysed, but we found evidence of decoupling of transmission and mobility following the relaxation of strict control measures for 80% of countries. For the majority of countries, mobility explained a substantial proportion of the variation in transmissibility (median adjusted R-squared: 48%, interquartile range - IQR - across countries [27–77%]). Where a change in the relationship occurred, predictive ability decreased after the relaxation; from a median adjusted R-squared of 74% (IQR across countries [49–91%]) pre-relaxation, to a median adjusted R-squared of 30% (IQR across countries [12–48%]) post-relaxation. In countries with a clear relationship between mobility and transmission both before and after strict control measures were relaxed, mobility was associated with lower transmission rates after control measures were relaxed indicating that the beneficial effects of ongoing social distancing behaviours were substantial.

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