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 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 Distribution characteristics of seepage field and prediction of water inflow before and after tunnel construction

2018 ◽  
Vol 232 ◽  
pp. 03014
Author(s):  
Ruilang Cao ◽  
Shijie Pang ◽  
Chang Huang ◽  
Chen Chen
Keyword(s):  
Water Pressure ◽  
Three Dimensional ◽  
Soft Rock ◽  
Parallel Line ◽  
Water Inflow ◽  
Distribution Characteristics ◽  
Seepage Field ◽  
Groundwater Environment ◽  
Before And After ◽  
External Water

In the construction of a deep tunnel with rich water and soft rock, accurate evaluations of the distribution characteristics of seepage field and water inflow are important bases for predicting the stability of tunnel surrounding rock and the disturbance state of groundwater environment. This paper used the Flac3D finite difference software seepage module, based on field geological borehole, measured seepage parameters and groundwater level. A three-dimensional numerical model of geological seepage in engineering area was established. The distribution characteristics of groundwater seepage field, the variation law of seepage field before and after tunnel excavation, and the water inflow during construction period were studied. As the tunnel was excavated, the excavated surface became a drainage channel, the isoline of groundwater pressure was changed into parallel non-parallel curve set by the parallel line of the initial seepage field. The nearer the tunnel centre was, the more obvious the variation tendency of groundwater pressure was. Grouting measures were very effective for tunnel water gushing, which not only reduced water inflow, but also effectively reduced the external water pressure of lining. It was infeasible to plug water when blocking the water without grouting and only adjusting the permeability of the lining.

Experimental investigation on the three-dimensional flow field from a meltblowing slot die

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 724-732
Author(s):  
Changchun Ji ◽  
Yudong Wang
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Distribution Characteristics ◽  
Air Velocity ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Airflow Distribution ◽  
Slot Die ◽  
Center Area

AbstractTo investigate the distribution characteristics of the three-dimensional flow field under the slot die, an online measurement of the airflow velocity was performed using a hot wire anemometer. The experimental results show that the air-slot end faces have a great influence on the airflow distribution in its vicinity. Compared with the air velocity in the center area, the velocity below the slot end face is much lower. The distribution characteristics of the three-dimensional flow field under the slot die would cause the fibers at different positions to bear inconsistent air force. The air velocity of the spinning centerline is higher than that around it, which is more conducive to fiber diameter attenuation. The violent fluctuation of the instantaneous velocity of the airflow could easily cause the meltblowing fiber to whip in the area close to the die.

scholarly journals Three-dimensional thermomechanical converting of CTMP substrates: effect of bio-based strengthening agents and new mineral filling concept

Cellulose ◽  
2021 ◽  
Vol 28 (15) ◽  
pp. 9751-9768
Author(s):  
Teija Laukala ◽  
Sami-Seppo Ovaska ◽  
Ninja Kerttula ◽  
Kaj Backfolk
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Three Dimensional ◽  
Microfibrillated Cellulose ◽  
New Mineral ◽  
Thermomechanical Pulp ◽  
Cationic Starch ◽  
Precipitated Calcium Carbonate ◽  
Filling Method ◽  
Positive Effect

AbstractThe effects of bio-based strengthening agents and mineral filling procedure on the 3D elongation of chemi-thermomechanical pulp (CTMP) handsheets with and without mineral (PCC) filling have been investigated. The 3D elongation was measured using a press-forming machine equipped with a special converting tool. The strength of the handsheets was altered using either cationic starch or microfibrillated cellulose. Precipitated calcium carbonate (PCC) was added to the furnish either as a slurry or by precipitation of nano-sized PCC onto and into the CTMP fibre. The 3D elongation of unfilled sheets was increased by the dry-strengthening agents, but no evidence on the theorised positive effect of mineral fill on 3D elongation was seen in either filling method. The performance of the strengthening agent depended on whether the PCC was as slurry or as a precipitated PCC-CTMP. The starch was more effective with PCC-CTMP than when the PCC was added directly as a slurry to the furnish, whereas the opposite was observed with microfibrillated cellulose. The 3D elongation correlated positively with the tensile strength, bursting strength, tensile stiffness, elastic modulus and bending stiffness, even when the sheet composition was varied, but neither the strengthening agent nor the method of PCC addition affected the 3D elongation beyond what was expectable based on the tensile strength of the sheets. Finally, mechanisms affecting the properties that correlated with the 3D elongation are discussed.

scholarly journals Three-dimensional analysis of the root canal preparation with Reciproc Blue®, WaveOne Gold® and XP EndoShaper®: a new method in vivo

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javier Caviedes-Bucheli ◽  
Nestor Rios-Osorio ◽  
Diana Usme ◽  
Cristian Jimenez ◽  
Adriana Pinzon ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Root Canal ◽  
Paired Comparison ◽  
Three Dimensional ◽  
New Method ◽  
Root Canal Preparation ◽  
Paired Data ◽  
Before And After ◽  
Student’S T

Abstract Background The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. Methods In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student’s t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. Results Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). Conclusion With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.

scholarly journals Scientific validation of three-dimensional stereophotogrammetry compared to the IGAIS clinical scale for assessing wrinkles and scars after laser treatment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Barbara Helena Barcaro Machado ◽  
Ivy Dantas De Melo E. Silva ◽  
Walter Marou Pautrat ◽  
James Frame ◽  
Mohammad Najlah
Keyword(s):  
Laser Treatment ◽  
Three Dimensional ◽  
Skin Surface ◽  
Clinical Scale ◽  
3D Images ◽  
Laser Resurfacing ◽  
Before And After ◽  
Measuring Outcomes ◽  
Skin Scar ◽  
Scientific Validation

AbstractMeasuring outcomes from treatments to the skin is either reliant upon patient’s subjective feedback or scale-based peer assessments. Three-Dimensional stereophotogrammetry intend to accurately quantify skin microtopography before and after treatments. The objective of this study is comparing the accuracy of stereophotogrammetry with a scale-based peer evaluation in assessing topographical changes to skin surface following laser treatment. A 3D stereophotogrammetry system photographed skin surface of 48 patients with facial wrinkles or scars before and three months after laser resurfacing, followed immediately by topical application of vitamin C. The software measured changes in skin roughness, wrinkle depth and scar volume. Images were presented to three observers, each independently scoring cutaneous improvement according to Investigator Global Aesthetic Improvement Scale (IGAIS). As for the results, a trend reflecting skin/scar improvement was reported by 3D SPM measurements and raters. The percentage of topographical change given by the raters matched 3D SPM findings. Agreement was highest when observers analysed 3D images. However, observers overestimated skin improvement in a nontreatment control whilst 3D SPM was precise in detecting absence of intervention. This study confirmed a direct correlation between the IGAIS clinical scale and 3D SPM and confirmed the efficacy and accuracy of the latter when assessing cutaneous microtopography alterations as a response to laser treatment.

Three-dimensional changes in root angulation of buccal versus palatal maxillary impacted canines after orthodontic traction: A retrospective before and after study

2021 ◽  
Author(s):  
Yalil Augusto Rodríguez-Cárdenas ◽  
Luis Ernesto Arriola-Guillén ◽  
Aron Aliaga-Del Castillo ◽  
Gustavo Armando Ruíz-Mora ◽  
Guilherme Janson ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Changes ◽  
Impacted Canines ◽  
Before And After ◽  
Before And After Study

scholarly journals The relationship between photometric and spectroscopic oscillation amplitudes from 3D stellar atmosphere simulations

2021 ◽  
Author(s):  
Yixiao Zhou ◽  
Thomas Nordlander ◽  
Luca Casagrande ◽  
Meridith Joyce ◽  
Yaguang Li ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Three Dimensional ◽  
Quantitative Relationship ◽  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Wavelength Shift ◽  
The Sun ◽  
Theoretical Derivation ◽  
Velocity Amplitude ◽  
Good Agreement

Abstract We establish a quantitative relationship between photometric and spectroscopic detections of solar-like oscillations using ab initio, three-dimensional (3D), hydrodynamical numerical simulations of stellar atmospheres. We present a theoretical derivation as proof of concept for our method. We perform realistic spectral line formation calculations to quantify the ratio between luminosity and radial velocity amplitude for two case studies: the Sun and the red giant ε Tau. Luminosity amplitudes are computed based on the bolometric flux predicted by 3D simulations with granulation background modelled the same way as asteroseismic observations. Radial velocity amplitudes are determined from the wavelength shift of synthesized spectral lines with methods closely resembling those used in BiSON and SONG observations. Consequently, the theoretical luminosity to radial velocity amplitude ratios are directly comparable with corresponding observations. For the Sun, we predict theoretical ratios of 21.0 and 23.7 ppm/[m s−1] from BiSON and SONG respectively, in good agreement with observations 19.1 and 21.6 ppm/[m s−1]. For ε Tau, we predict K2 and SONG ratios of 48.4 ppm/[m s−1], again in good agreement with observations 42.2 ppm/[m s−1], and much improved over the result from conventional empirical scaling relations which gives 23.2 ppm/[m s−1]. This study thus opens the path towards a quantitative understanding of solar-like oscillations, via detailed modelling of 3D stellar atmospheres.

Weight-Reduction Optimization Design for Milling Planer Bed Based on Finite Element Analysis

2012 ◽  
Vol 490-495 ◽  
pp. 2785-2789
Author(s):  
Dong Sun ◽  
Xu Dong Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Weight Reduction ◽  
Optimization Design ◽  
Weak Link ◽  
Three Dimensional ◽  
Production Costs ◽  
Element Analysis ◽  
Before And After ◽  
Improvement Scheme

The milling planer bed is one of the most important foundational parts for the entire machine, sufficient stiffness is required. The posterior segment of a certain milling planer bed is regarded as the optimization object in this paper. Three-dimensional modeling method is used to calculate the exact weight of the bed and then finite element analysis is used to research the static and dynamic characteristics before and after weight-reduction. The weak link of the bed is found out and a improvement scheme is put forward ensuring lower production costs under the premise of sufficient rigidity.

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