scholarly journals Effect of initial conditions on strength of unsaturated compacted loess soil

2014 ◽  
Keyword(s):  
Initial Conditions ◽  
Loess Soil ◽  
Compacted Loess

Test Investigation on Mechanical of Unsaturated Loess

2012 ◽  
Vol 204-208 ◽  
pp. 22-27
Author(s):  
Yan Zhu ◽  
Yun Xu Chen
Keyword(s):  
Water Content ◽  
Horizontal Plane ◽  
Mechanical Characteristics ◽  
Loess Soil ◽  
Dry Density ◽  
One Dimensional ◽  
Test Investigation ◽  
Unsaturated Loess ◽  
Test Result ◽  
Compacted Loess

Compression and collapse of unsaturated compacted loess are studied by using dry density and water content which easily controlled in engineering, the controlling range of dry density and water content are confirmed respectively. Then the deformation of compression and collapse and the frequency of engineering damager occurrence can be decreased. In addition, the mechanical characteristics of loess in different directions may differ because the loess was consolidated only under the condition of its upper weight of soil and load. The conventional mechanical experiments, including one-dimensional compress and collapse test, were conducted with the specimen of loess soil in different angle from the original horizontal plane. The test result shows that the loess is anisotropic

scholarly journals Effect of Admixture on the Hydraulic Conductivity of Compacted Loess: A Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Pan Liu ◽  
Xuejiao Zhang ◽  
Min Zhang ◽  
Xueqiang Yang
Keyword(s):  
Hydraulic Conductivity ◽  
Land Surface ◽  
Safety Evaluation ◽  
Loess Soil ◽  
Local Area ◽  
High Density ◽  
Lateritic Soil ◽  
Distribution Area ◽  
Engineering Practice ◽  
Compacted Loess

Hydraulic characteristic of the exposed ground plays an important role in the construction of “sponge city,” which is a popular concept in the world recently. Loess soil, which is a common geomaterial in its distribution area approximately 9.3% of the world’s land surface, usually could not satisfy the engineering requirement only by compacting without any other treatments. This paper aims to investigate the effect of a natural geomaterial, lateritic soil, which is more economical and environmental than the traditional admixtures such as cement and lime, on the saturated hydraulic conductivity (ksat) of compacted loess. A series of falling-head permeability tests on pure loess and lime-treated loess were carried out firstly for comparison; then lime-treated loess mixed with different contents of lateritic soil was tested. To verify the availability of the coverage of high density lateritic soil on pure loess for antipermeability, which is a common treatment in local area, tests of different thickness of the coverage were conducted. The test results revealed that the admixture of lime could obviously decrease ksat of pure loess and 3% might be the most economical content. An empirical algorithm was proposed based on the results to estimate ksat of lime-treated loess of which the lime content is out of the scope studied in this paper, and it would be useful for engineering design and numerical simulation of safety evaluation. The addition of lateritic soil in the 3% lime-treated loess could further decrease ksat and its performance for antipermeability was better than increasing the lime contents simply. The coverage of high density lateritic soil could also improve the antipermeability of loess, and thickness at least of 30 mm was suggested for engineering practice.

scholarly journals Estimation of modulus of elasticity of compacted loess soil and lateritic-loess soil from laboratory plate bearing test

2022 ◽  
Vol 16 ◽  
pp. e00837
Author(s):  
Prinya Chindaprasirt ◽  
Arkhom Sriyoratch ◽  
Anukun Arngbunta ◽  
Panatchai Chetchotisak ◽  
Peerapong Jitsangiam ◽  
...  
Keyword(s):  
Modulus Of Elasticity ◽  
Loess Soil ◽  
Compacted Loess

scholarly journals A study on the effect of pore and particle distributions on the soil water characteristic curve of compacted loess

2021 ◽  
Author(s):  
Yu Wang ◽  
Tonglu Li ◽  
Chenxi Zhao ◽  
Xiaokun Hou ◽  
Ping Li ◽  
...  
Keyword(s):  
Soil Water ◽  
Construction Projects ◽  
Characteristic Curve ◽  
Loess Soil ◽  
Northwest China ◽  
Water Infiltration ◽  
Dry Density ◽  
Particle Distributions ◽  
Water Characteristics ◽  
Compacted Loess

Abstract Compacted loess soil is used as a geo-material in many engineering projects such as building foundations and highway embankments. Water infiltration characteristics and post settlement of the compacted loess in large construction projects of Northwest China have received increasing attention from researchers and investors. These behaviors are closely related to the soil water characteristics. This study aims to investigate the soil water characteristic curves (SWCCs) of compacted loess soil with different dry densities and to reveal the responsible micro-mechanisms for soil water characteristics. Loess soil collected from the new district of Yan'an City, China, is prepared into five dry density groups. The SWCC of each group in the suction range of 0–100,000 kPa is measured using the filter paper method (FPM). Two-dimensional (2D) images and the pore size distribution (PSD) curves of the specimens are tested by scanning electron microscopy (SEM) and the mercury pressure method (MIP), respectively. The results of this study highlight that the compaction behavior mainly influences the pores with a radius ( r ) in the range of 1–10 μm, and has no influence on the pores of r < 0.5 μm. The particle shapes among the five dry densities groups are similar. The characteristics of the PSD curves of the compacted loess soil correspond well to the SWCCs. The suction of the SWCCs increases with increasing dry density in the lower suction range of 0–100 kPa. In contrast, suction among the five dry density groups is almost identical in the suction range exceeding 100 kPa. The results of the study are helpful to understand the SWCC and microstructure characteristics of compacted loess with different dry densities.

Sebuah Generalisasi Baru Barisan Fibonacci-Lucas

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Musraini M Musraini M ◽  
Rustam Efendi ◽  
Rolan Pane ◽  
Endang Lily
Keyword(s):  
Recurrence Relation ◽  
Initial Conditions ◽  
Lucas Sequence ◽  
Binet’S Formula

Barisan Fibonacci dan Lucas telah digeneralisasi dalam banyak cara, beberapa dengan mempertahankan kondisi awal, dan lainnya dengan mempertahankan relasi rekurensi. Makalah ini menyajikan sebuah generalisasi baru barisan Fibonacci-Lucas yang didefinisikan oleh relasi rekurensi B_n=B_(n-1)+B_(n-2),n≥2 , B_0=2b,B_1=s dengan b dan s bilangan bulat  tak negatif. Selanjutnya, beberapa identitas dihasilkan dan diturunkan menggunakan formula Binet dan metode sederhana lainnya. Juga dibahas beberapa identitas dalam bentuk determinan.   The Fibonacci and Lucas sequence has been generalized in many ways, some by preserving the initial conditions, and others by preserving the recurrence relation. In this paper, a new generalization of Fibonacci-Lucas sequence is introduced and defined by the recurrence relation B_n=B_(n-1)+B_(n-2),n≥2, with ,  B_0=2b,B_1=s                          where b and s are non negative integers. Further, some identities are generated and derived by Binet’s formula and other simple methods. Also some determinant identities are discussed.

Meningkatkan Kemampuan Guru dalam Menerapkan Model Pembelajaran Problem Centered Learning Melalui Focus Group Discission di Sekolah Dasar Negeri 187/X Bangun Karya Tahun 2019/2020

2020 ◽  
Vol 10 (1) ◽  
pp. 86
Author(s):  
Mujiem Mujiem
Keyword(s):  
Elementary School ◽  
Action Research ◽  
Focus Group ◽  
Initial Conditions ◽  
Learning Model ◽  
Class Action ◽  
Learning Activities ◽  
Implementation Phase ◽  
The Subject ◽  
Academic Year

This research is a classroom action research that aims to improve the ability of teachers to apply the problem centered learning model of learning in the Elementary School 187/ X Bangun Karya, Academic Year 2019/2020. The subject of this study was a teacher at 187 / X Bangun Karya Elementary School, Rantau Rasau District, Tanjung Jabung Timur District, Jambi Province. This class action research was carried out in two cycles, each cycle consisting of two meetings. The results of the evaluation are converted into a recapitulation table of the results of cycle I. The conversion results state that the research has not yet reached the target, it needs to be continued with cycle II. The results of observers in the implementation phase of the second cycle showed that all parts of the learning activities were going well, so that there were no more parts of the learning activities that needed to be improved. While the results of the second cycle are converted with the results of the recapitulation table states that the study has reached the target limit of completeness criteria in the first cycle that is equal to 50% and an average of 68.7 in the initial conditions of improvement in the second cycle completeness criteria to be 100% and the average namely 91.7 states that the Focus Group Discission can improve the ability of teachers to apply the Problem Centered Learning learning model in learning in 187 / X Public Elementary School Build Work Year 2019/2020.

Dynamics of the macromolecular composition of the biomass of microalgae in the morning under natural light. Model

2020 ◽  
pp. 45-52
Author(s):  
Alexander S. Lelekov ◽  
Anton V. Shiryaev
Keyword(s):  
Biochemical Composition ◽  
Initial Conditions ◽  
Natural Light ◽  
Photoautotrophic Growth ◽  
Structural Part ◽  
Basic Model ◽  
Microalgae Culture ◽  
Simulation Results ◽  
Structural Parts ◽  
Macromolecular Composition

The work is devoted to modeling the growth of optically dense microalgae cultures in natural light. The basic model is based on the idea of the two-stage photoautotrophic growth of microalgae. It is shown that the increase in the intensity of sunlight in the first half of the day can be described by a linear equation. Analytical equations for the growth of biomass of microalgae and its macromolecular components are obtained. As the initial conditions, it is assumed that at the time of sunrise, the concentration of reserve biomass compounds is zero. The simulation results show that after sunrise, the growth of the microalgae culture is due only to an increase in the reserve part of the biomass, while the structural part practically does not change over six hours. Changes in the ratio of the reserve and structural parts of the biomass indicate a change in the biochemical composition of cells.

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