scholarly journals Experimental Study on the Effect of Compaction Work and Defect on the Strength of Soil-Rock Mixture Subgrade

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xin Yan ◽  
Wei Zhan ◽  
Zhi Hu ◽  
Yiqiang Yu ◽  
Danqiang Xiao
Keyword(s):  
Resilient Modulus ◽  
Good Condition ◽  
Stress Transfer ◽  
Loose Body ◽  
Earth Dam ◽  
Filling Material ◽  
Test Results ◽  
Engineering Characteristics ◽  
Modulus Of Resilience ◽  
Geotechnical Tests

Soil-rock mixture is a common filling material for earth dam and subgrade. In this study, research concerned on the evolution law of engineering characteristics of soil-rock mixture under different factors and the effect of defect on subgrade strength, and geotechnical tests were carried out to analyze the influence of different factors on engineering characteristics of soil-rock mixture in the study, and the physical model was carried out to analyze the effect of different compaction works on the resilient modulus, and the influence of defect on the strength was explored by manually preset loose body. The test results showed that (1) when the soil-rock mixture was graded, P = 78, the moisture content was 14%, and the engineering characteristics were optimal; (2) there was a positive correlation between compaction times and resilient modulus, and the stress transferred from the subgrade to soil was linearly distributed under the good condition of compactness; and (3) the existence of loose body not only reduces the modulus of resilience but also affects the stress transfer; the larger the loose body, the lower the resilient modulus and the greater the stress transfer.

scholarly journals Bearing Behavior of the Fly Ash Deposits on Expressway

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Chun-yu Cui ◽  
Shu-jian Wang ◽  
Wei Cui ◽  
Xiao Zheng
Keyword(s):  
Fly Ash ◽  
Bearing Capacity ◽  
Void Ratio ◽  
Good Condition ◽  
Maximum Level ◽  
Engineering Properties ◽  
Filling Material ◽  
Bear Capacity ◽  
Modulus Of Resilience ◽  
Bearing Behavior

The reinforcement treatment for embankment using the fly ash deposits as the filling material for roadbed was clarified in this paper. Studies have shown that fly ash can be used as the filling material for embankment, but the subgrade bearing capacity from the original fly ash deposits cannot meet the requirements for operating. Fly ash has a good condition to run the dynamic consolidation for meeting the requirements of embankment compaction. The modulus of resilience and the California bearing ratio (CBR) of fly ash is close to that of general filling material for embankment. Fly ash also has the engineering properties of high void ratio and low cohesion. The maximum level of compaction of the fly ash deposits can be 93% and the bear capacity can be about twice over before after the treatment.

Experimental Study of Fatigue Performance of Stay Cable Damper

2014 ◽  
Vol 487 ◽  
pp. 404-407
Author(s):  
Dong Liang ◽  
Zi Shuo Li
Keyword(s):  
Experimental Study ◽  
Good Condition ◽  
Experimental Results ◽  
Test Results ◽  
Stay Cable ◽  
Damping Force ◽  
Durability Test ◽  
Equivalent Damping ◽  
Stay Cables ◽  
Performance Deterioration

Oil dampers are widely used as a popular countermeasure to mitigate the stay cables vibration. In this study, one actual oil damper designed for some long cable-stayed was experimentally investigated to evaluate the durability. 4 million cycles loading, with frequency of 4 Hz and amplitude of 1 mm, was imposed on the damper. The excitation displacement and damping force were measured and the equivalent damping was calculated from the experimental results. The stiffness effects of dampers behaved during durability tests were also analyzed quantitatively. The test results showed that the dampers were still in good condition after 4 million cycles loading and the dampers temperatures were stable at 50 degree centigrade during the test. According to the durability test results, a model for performance deterioration of damper was proposed to predict the lifetime of oil dampers.

Using Genetic Algorithms to Set Target Values for Engineering Characteristics in the House of Quality

1999 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan Colton
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Penalty Functions ◽  
Preliminary Design ◽  
Test Results ◽  
House Of Quality ◽  
Design Specifications ◽  
Engineering Characteristics ◽  
Target Values

Abstract As part of a strategy for obtaining preliminary design specifications from the House of Quality, genetic algorithms were used to generate and optimize preliminary design specifications for an automotive case study. This paper describes the House of Quality for the automotive case study. In addition, the genetic algorithm chosen, the genetic coding, the methods used for mutation and reproduction, and the fitness and penalty functions are descrobed. Methods for determining convergence are examined. Finally, test results show that the genetic algorithm produces reasonable preliminary design specifications.

scholarly journals Efficacy Of Two NI-TI Retreatment Systems and Hand Files in Removing Gutta-Percha and Sealer From Root Canals Filled With Three Different Types of Sealers

2015 ◽  
Vol 03 (02) ◽  
pp. 071-079
Author(s):  
Rajender Singh ◽  
Ashu Gupta ◽  
Vishal Sharma
Keyword(s):  
Operating Time ◽  
Filling Material ◽  
Test Results ◽  
Root Canals ◽  
Gutta Percha ◽  
Honestly Significant Difference ◽  
Working Length ◽  
Significant Difference ◽  
Hand Instrumentation ◽  
Difference Test

Abstract Objectives: This study was undertaken to evaluate the efficiency of two rotary nickel titanium instruments and hand instrumentation in removing gutta-percha and sealer from root canals. Study design: – 63 extracted human single rooted premolars were instrumented with K-files and filled using lateral compaction of gutta-percha (GP) and three different sealers. The teeth were randomly divided into three experimental groups of 21 specimens each. Removal of gutta-percha was performed with R-Endo retreatment files, Mtwo retreatment files and Hedstrom files. Time to reach working length and to eliminate filling material was also recorded. The specimens were sectioned for evaluation of the area of the remaining gutta-percha/sealer under stereomicroscope at 6X magnification. Photographs were taken for further analysis using computer image analysis program. The results were statistically analyzed using Analysis of variance (ANOVA) and Tukey’s honestly significant difference test. Results: The R-Endo retreatment system resulted in a smaller percentage of canal area covered by residual GP/sealer than in other groups, a significant difference was found between R-Endo and Mtwo group and between Hedstrom groups (P < 0.001). The Mean operating time was minimum with R-Endo group while it was found to be maximum with hand files. Conclusion: It was concluded that all test techniques left gutta-percha/sealer remnants within the root canal. The R-Endo retreatment files and Mtwo retreatment files system proved to be an efficient method for removing gutta-percha and sealer from single rooted premolars.

Study on Correction Method of Subgrade Modulus Based on FWD

2013 ◽  
Vol 579-580 ◽  
pp. 862-865
Author(s):  
Xiao Hua Luo ◽  
Qing Yang ◽  
Xin Qiu
Keyword(s):  
Resilient Modulus ◽  
Implementation Process ◽  
Correction Method ◽  
Deformation Analysis ◽  
Test Results ◽  
Moisture Condition ◽  
Back Calculation ◽  
The Mean ◽  
Subgrade Modulus ◽  
New Perspective

In order to calibrate subgrade back calculation modulus, the correction method of subgrade back calculation modulus was put forward based on theoretical analysis and indoor/outdoor experiments, and the detailed implementation process was analyzed combined the latest results of subgrade dynamic modulus and subgrade moisture forecast. The results show that the equivalent resilient modulus of subgrade simultaneously consider subgrade material moisture condition and stress dependency and the forecast equation has higher correlation. The ratio of the loading plate test results to the predicted results ranges from 0.25 to 0.4 and the mean is 0.32, which conforms to the requirements of AASHTO normal value. Utilizing the scale factor 0.65 to calibrate subgrade back calculation modulus is viable and validated. The results provides a new perspective and approach for deformation analysis of subgrade structure. As well, the established method makes up the defect that can't reflect the effect of moisture and stress on equivalent resilient modulus of subgrade.

Collecting and Handling Milk Samples

1975 ◽  
Vol 38 (2) ◽  
pp. 108-110 ◽  
Author(s):  
SIDNEY E. BARNARD ◽  
EDWARD D. GLASS
Keyword(s):  
Good Condition ◽  
Test Results ◽  
Milk Samples ◽  
Proper Analysis ◽  
Representative Samples ◽  
Proper Sampling

Accurate quality and compositional test results depend on representative samples and proper analysis. Proper sampling and handling are essential to prevent contamination and to maintain temperatures between 33 and 40 F. Representative samples must be delivered to the laboratory in good condition to insure the reliability of quality and compositional tests.

Evaluation of Variability in Resilient Modulus Test Results (ASTM D 4123)

1991 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
A Wolfenden ◽  
ER Brown ◽  
KY Foo
Keyword(s):  
Resilient Modulus ◽  
Test Results

Properties of Porous Asphalt Mixture Made with Styrene Butadiene Styrene under Long Term Oven Ageing

2012 ◽  
Vol 486 ◽  
pp. 378-383 ◽  
Author(s):  
Che Wan Che Norazman ◽  
Ramadhansyah Putra Jaya ◽  
Meor Othman Hamzah
Keyword(s):  
Resilient Modulus ◽  
Asphalt Mixture ◽  
Test Results ◽  
Air Voids ◽  
Porous Asphalt ◽  
Coefficient Of Permeability ◽  
Modified Binder ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Oven ageing is a set of procedure to simulate the accelerated effects of ageing on pavements structures. In this study, the effect of long-term oven ageing on porous asphalt mixture made with SBS modified binder was investigated. The resilient modulus, water permeability and air voids test results were the performance indicators used to evaluate the effects of ageing. The test results showed that, the resilient modulus of long term aged specimens was higher than those of unaged specimens. From the permeability test results, unaged SBS mixes exhibit lower coefficient permeability compared to the corresponding long-term oven age specimens. Most likely, ageing caused binder hardening, making the mix more difficult to compact and hence exhibited more continuous voids which in turn lead to higher permeability. In addition, the coefficient of permeability decreases as the binder content increased.

Experimental Study on Mechanical Behaviors of Lime-Stabilized Soils with Small Lime Content

2011 ◽  
Vol 374-377 ◽  
pp. 1823-1826
Author(s):  
Zhong Yu Liu ◽  
Yong Gang Xue ◽  
Xi Jun Wang
Keyword(s):  
Compression Strength ◽  
Compression Modulus ◽  
Curing Time ◽  
Test Results ◽  
Unconfined Compression Strength ◽  
Unconfined Compression ◽  
Mechanical Behaviors ◽  
Lime Content ◽  
Modulus Of Resilience ◽  
Resilience Modulus

In order to investigate the mechanical behaviors of lime-stabilized soils with small lime content, the specimens with 4%~8% lime content and 90%~95% degree of compaction are prepared, and then in use for the unconfined compression strength test, the diametral compression test and the compression resilience modulus test after they have cured in a standard curing room for 7 to 180 days respectively. These test results show that all of the unconfined compression strength, the splitting strength and the compression modulus of resilience increase with the degree of compaction and the curing time. Thereinto, the compression modulus of resilience does rapidly between 28 and 90 curing days, and the unconfined compression strength of the soil with 4% lime content does little after 28 curing days while the compression strengths and the splitting strengths of the other soils do quickly until 90 curing days. In addition, for a given degree of compaction, these strengths of the soils with the less lime content are potentially greater at the early curing time.

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