scholarly journals Influencing Factors on the Accuracy of Soil Calibration Models by EDG

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1892
Author(s):  
Haoming Yang ◽  
Xiaoping Yang ◽  
Min Zhang ◽  
Jiaojian Hou
Keyword(s):  
Water Content ◽  
Correlation Coefficients ◽  
Dry Density ◽  
Engineering Practice ◽  
Calibration Model ◽  
Test Results ◽  
Probability Curve ◽  
Factors Affecting ◽  
Applicable Range ◽  
New Type

Compaction is an important standard in evaluating the quality of earth filling work. The EDG, an electrical density gauge, is a new type of fast and nondestructive compaction detection equipment. It is used to test the dry density and water content of the soil by establishing a soil calibration model while the accuracy of measurement is mainly based on the precision of equation of calibration model. In this paper, the factors affecting the accuracy of the soil calibration model were studied by an indoor calibration test, and soil samples were prepared to verify the accuracy of the soil calibration model. The test results showed that the dry density range, water content range, and sample quantity 13 samples of soil had a significant influence on the correlation coefficient (R2) of the equation of the soil calibration model. In addition, when using the calibration model with different sample numbers and sample combinations but similar correlation coefficients to test multiple groups of density and moisture content, there are also differences in the expected value and standard deviation of the error probability curve of the test results. In the engineering practice, the reasonable sample quantity was determined by the applicable range of dry density and water content obtained from the measurement error analysis of the soil calibration model.

Investigation of factors affecting the seam slippage of garments

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4756-4765
Author(s):  
Daoling Chen ◽  
Pengpeng Cheng
Keyword(s):  
Regression Analysis ◽  
Linear Equation ◽  
Linear Density ◽  
Breaking Strength ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Test Results ◽  
Factors Affecting ◽  
Polyester Material ◽  
Sewing Thread

Seam slippage often occurs with some garments during the process of wearing or washing, which not only affects the appearance of the garment but also influences garment quality. The purpose of this study is to find out the factors that affect the seam slippage of garments. In order to make the test results closer to those of the garment itself, this study first proposed to make the fabric into a Japanese woman's prototype sample, in order to simulate the garments produced by a garment enterprise. Then, according to standards GB/T 13772.2-2008/ISO 13936-2: 2004 and GB/T 21294-2014, samples were made and seam slippage at the armhole and side seam was tested. Experimental results reveal that the factors that cause the seam slippage of garments are the fabric, seam type and sewing thread. According to the regression analysis, the seam type has a significant effect on the seam slippage of the armhole and side seam, with Pearson correlation coefficients of −0.715 and −0.650, respectively. Thickness, weight, weft density and weave type of the fabric are also important in terms of seam slippage. The weight of the fabric is more significant than other factors; the significant values at the armhole and side seam are 0.009 and 0.002, respectively. In the linear equation, it is shown that weft breaking strength of the fabric only impacts the seam slippage at the side seam. Sewing thread is another important factor for the seam slippage of garments, and its influence on the armhole is obvious; the larger the sewing thread linear density of polyester material is, the smaller the seam slippage is.

Experimental Study on the Improvement of High Water Content Dredged Material by Cement and by Quicklime

2014 ◽  
Vol 878 ◽  
pp. 714-719 ◽  
Author(s):  
Ying Hao Huang ◽  
Chan Dong ◽  
Xiao Lei Zhan ◽  
Yun Fei Guan
Keyword(s):  
Water Content ◽  
High Water ◽  
High Water Content ◽  
Dry Density ◽  
Dredged Material ◽  
Test Results ◽  
Environmental Friendly ◽  
Dredged Materials ◽  
Beneficial Uses ◽  
Modified Soil

Dredging is necessary to keep rivers, harbors and lakes function normally. These dredged materials (DM) have poor geotechnical properties and are normally treated as wastes. Thus, utilization of DM for beneficial uses such as fill is being considered as an environmental-friendly and economical option. In this study a dredged material taken from Tai-hu Lake was modified by adding quicklime and by Portland cement. Water content, dry density, plasticity, and California bearing ratio (CBR) of the two types of modified soil were determined and compared. Test results show that both quicklime and cement can evidently decrease the water content and increase dry density, but the former can get better effect relatively. On the other hand, both quicklime and cement can significantly decrease the plasticity characteristics, and change the raw DM classified as CH to MH after modified, moreover, the cement has better effect on the improvement of plasticity. For the same additive content and curing days, the cement modified soil has larger CBR strength than that of the quicklime modified soil. Conclusions of the paper maybe beneficial and useful for the solidification material choose, and for practical dredged material solidification projects.

Density Influence on Matric Suction of the Eolian Sand under the Condition of Loop of Dehumidifying and Humidifying Process

2011 ◽  
Vol 250-253 ◽  
pp. 2157-2160
Author(s):  
Yan Xun Song ◽  
Qiang Xu ◽  
Xi An Li ◽  
Hong Zhou Lin
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Matric Suction ◽  
Dry Density ◽  
Test Results ◽  
Unsaturated Sand ◽  
Water Characteristics ◽  
Eolian Sand ◽  
The Relationship ◽  
Variation Tendency

The matric suction has very important influence on the characteristics of unsaturated sand; and it is closely relevant to density. In order to discuss the relationship among the matric suction, water content and dry density, the matric suction of the eolian sand were measured in laboratory. The soil-water characteristics curves for unsaturated eolian sand with different dry densities are obtained. The test results show that the variation tendency of soil-water characteristics curves has been corresponding to the different densities.

scholarly journals Factors affecting the swelling pressure for Jerash expansive soil

2021 ◽  
Vol 3 (2) ◽  
pp. 44-51
Author(s):  
Talal Masoud ◽  
Abdulrazzaq Jawish Alkherret
Keyword(s):  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Dry Density ◽  
Initial Water Content ◽  
Content Increase ◽  
Initial Water ◽  
Factors Affecting ◽  
Water Content Increase

  In this study for factors effecting the swelling pressure of jerash expansive soils were investigated in this study, effect of initial dry density and effect of initial water content on the jerash expansive soil were investigated.It show that as the initial dry density decrease from 1.85 gm/cm3  to1.25 gm/cm3 , the swelling pressure also decrease are from 3.1  to 0.25gm/cm2   also it show that as the initial water content increase from 0%to 15% , the swelling pressure of jerash expansive soil decrease from 2.65 gm/cm2  to 1.35 gm/cm2  .  

scholarly journals Optimizing the Compaction Characteristics and Strength Properties of Gravelly Soils in terms of Fine Contents

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Mingzhi Zhao ◽  
Gang Liu ◽  
Longxiang Deng ◽  
Yangang Li
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Triaxial Test ◽  
Soil Structure ◽  
Fine Particles ◽  
Strength Properties ◽  
Coarse Grained ◽  
Dry Density ◽  
Engineering Practice ◽  
Gravelly Soils

Gravelly soils are widely adopted as civil construction materials in engineering practice. Although the influence mechanism of fine contents (FCs) on the mechanical behavior of gravelly soils has been emphasized in the previous studies, few discuss the compaction and strength properties concurrently. Besides, FCs of gravelly soils were discussed separately in many cases regardless of the variation in water content. In this study, modified Proctor compaction test and medium-sized triaxial test were performed to investigate the mechanical properties of gravelly soils containing different magnitudes of fine contents. It is shown that an optimum FC exists for gravelly soils although the value of the optimum FC varies with grading curves of the coarse-grained portion. By adjusting FC in the gravelly soils, not only could the maximum dry density ρdmax be improved but also the optimum saturation degree Sropt rises significantly, and synchronously, the minimum air void ratio v a min decreases notably. Besides, fine particles are just right to fill with the voids formed by the coarse-grained skeleton for the optimum FC sample. The soil structure corresponding to the optimum FC status can be termed as a densely filled skeleton structure, which is the densest and most stable. As fine contents increase or decrease from the optimum value, soil structure will loosen and deteriorate the mechanical properties. In addition, the increase in water content has quite different effects on strength properties of gravelly soils with different FCs in a triaxial test due to the opposite effects of pore water softening and negative pore pressure strengthening. Such results are expected to provide guidance for the preparation of gravelly soils in engineering practices.

A New Type of Tackmeter

1964 ◽  
Vol 37 (1) ◽  
pp. 28-37 ◽  
Author(s):  
O. K. F. Bussemaker ◽  
W. V. C. van Beek
Keyword(s):  
Testing Procedure ◽  
Test Results ◽  
Factors Affecting ◽  
Sample Compression ◽  
New Type

Abstract A new type of tackmeter is described. Strips of the material to be tested are used for tack measurements. The instrument compresses and separates the strips under conditions which can be arbitrarily selected. The tackmeter is of rugged design for simple handling and ease of operation. The test results are recorded on a chart, enabling easy reading of the results. A description of the tackmeter and the testing procedure is given. The accuracy of the measurement is briefly discussed. Among the factors affecting the measurement are the thickness of the sample, compression conditions and aging of the surface. Some test results obtained with factory-made plies and compounds with varying black loadings are given.

scholarly journals A New Buckling-Restrained Brace with a Variable Cross-Section Core

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Liang Li ◽  
Tianhua Zhou ◽  
Junwu Chen ◽  
Jianfeng Chen
Keyword(s):  
Energy Dissipation ◽  
Cross Section ◽  
Variable Cross Section ◽  
Engineering Practice ◽  
Variable Cross ◽  
Test Results ◽  
Buckling Restrained Brace ◽  
Practical Design ◽  
Mechanical Behaviours ◽  
New Type

In this paper, a new type of buckling-restrained brace characterized by a variable cross-section core (BRB-VCC) is proposed and investigated. The practical design equations of the BRB-VCC are derived based on mechanical and mathematical theories. Six specimens are designed and tested to clarify the mechanical behaviours of the BRB-VCC and to validate the reliability of the proposed equations. The test results show that (1) none of the specimens buckle under compression, as expected, and their ductilities and energy dissipation capacities are satisfactory; (2) the derived formulas are reliable and can be conveniently used in engineering practice; and (3) the yielding displacement of the BRB-VCC is approximately 70% that of the traditional TJ-1 buckling-restrained brace (BRB-TJ-1), which may yield earlier than the BRB-TJ-1 in concrete structures under the action of an earthquake.

scholarly journals Experimental Study on Normal Frost-Heave Force Generated from Loess upon Freezing considering Multiple Factors

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Zai-kun Zhao ◽  
Tie-hang Wang ◽  
Xin Jin ◽  
Yu Zhang
Keyword(s):  
Experimental Study ◽  
Water Content ◽  
Freezing Temperature ◽  
Frost Heave ◽  
Dry Density ◽  
Force Model ◽  
Test Results ◽  
Multiple Factors ◽  
Water Contents ◽  
Good Agreement

An experimental study on the normal frost-heave force generated by loess was conducted by subjecting loess with various water contents and densities to different temperature conditions. The experimental results show that the interaction of the three factors has a significant effect on the normal frost-heaving force. Normal frost-heave force increases exponentially with an increase in dry density and linearly with a reduction in the freezing temperature or an increase in water content; of these factors, dry density has the greatest influence on frost-heave force, followed by water content then temperature. A frost-heave force model is developed that includes overall consideration of the interactions of water content, density, and temperature based on fitting of the test results. The value calculated with the model is in good agreement with values measured in verification tests, indicating that the model has high accuracy and can provide scientific guidance for engineering design in loess areas.

Research on Structural Composition and Seismic of Gypsum - Adobe Wall Dwellings

2011 ◽  
Vol 368-373 ◽  
pp. 1111-1116
Author(s):  
Tie Gang Zhou ◽  
Chen Ma ◽  
Ying Xu
Keyword(s):  
Shaking Table Test ◽  
Shaking Table ◽  
Wall Structure ◽  
Residential Construction ◽  
Engineering Practice ◽  
Test Results ◽  
Wall Surface ◽  
New Type ◽  
Green Earth ◽  
Composite Wall

Gypsum-adobe wall structure is a new type of green earth building. The feature of its structure is that the wall uses adobe and plaster as its main materials.The wall is erected by putting rods or stems of plants between layers of adobe, and is poured gypsum slurry into the gaps between adobe bricks and on the wall surface. Then adobe and plaster solidify and come to a composite wall structure. Finally，Gypsum and adobe bricks interact and bear stress together. This paper focuses on fully describing the shaking table test of a 1/4 scale house model of the structure. The Test results and engineering practice show that the single-storey gypsum-adobe wall structure has a good seismic performance and is worth promoting in residential construction of the drought areas.

Study on Moisture Modification for Resilient Modulus of Subgrade

2013 ◽  
Vol 361-363 ◽  
pp. 1460-1466
Author(s):  
Cong Li ◽  
Wei Lan
Keyword(s):  
Water Content ◽  
Resilient Modulus ◽  
Basic Rule ◽  
Repeated Loading ◽  
Dry Density ◽  
Test Results ◽  
Loading Test ◽  
Test Analysis ◽  
Fine Grained ◽  
Influence Degree

Subgrade resilient modulus of 3 typical soils, namely sand, silt and clay, have been measured under different conditions of 2 target dry density and 3 target water content by triaxial repeated-loading test. Analysis has been focused on the effect law of subgrade moisture and compaction for resilient modulus based on test results. Subgrade moisture has some impact on resilient modulus of test soils, especially on that of fine-grained soils. The influence degree of subgrde compaction depends on soil group. Coefficient of moisture modification has been introduced to characterize relationship between subgrade moisture and resilient modulus. Two-parameter Logistic model with inflexion control has been proposed according to the following basic rule. Coefficient of moisture modification usually increases or decreases along with the decrement or increment of subgrade moisture. And then variety rate of coefficient becomes small in state of high or low water content.

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