scholarly journals Effect of Sand Compaction Piles on the Swelling and Shrinkage Behavior of Expansive Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mohamed M. A. Hussein
Keyword(s):  
Applied Pressure ◽  
Expansive Soil ◽  
Heating System ◽  
Vertical Movement ◽  
Expansive Clay ◽  
Swelling Potential ◽  
Time Intervals ◽  
Regular Time ◽  
Shrinkage Behavior ◽  
Shrinkage Potential

This study aims to investigate the effect of sand compaction piles on the swelling and shrinkage behavior of expansive clay soil. A series of experimental laboratory tests were carried out using the modified Proctor mold and a circular footing. The diameter of the sand compaction pile was selected to give a replacement area ratio equal to 57%. To model the swelling and shrinkage cycles, water was added to the sample and the heave was recorded at regular time intervals. The shrinkage was obtained by heating the outer surface of the modified Proctor mold at a temperature of 110°C ± 5°C by a development heating system designed for this purpose to accelerate the shrinkage process. The vertical movement was recorded at regular time intervals. The swelling and shrinkage cycles were carried out under an externally applied pressure equal to 120 kPa. The main results of this study showed that, for untreated expansive soil, the swelling potential reaches the highest value at the second cycle and started to decrease for the subsequent cycles. After the fourth cycle, the swelling potential decreases and reaches about half the value of the initial swelling potential and the equilibrium state occurs. For expansive soil treated with a sand compaction pile, it is found that there is a significant reduction in both swelling and shrinkage potential. Moreover, it is observed that after the first cycle both the swelling and shrinkage potential decrease significantly, and both reach a negligible value after the second cycle.

Analysis of a New Expansive Soils Stabilization Method Made from Eco-Cement and Fiber Reinforcement

2013 ◽  
Vol 649 ◽  
pp. 217-222
Author(s):  
Mircea Aniculaesi ◽  
Anghel Stanciu ◽  
Irina Lungu
Keyword(s):  
Portland Cement ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Fiber Reinforcement ◽  
Synthetic Fiber ◽  
Expansive Clay ◽  
Swelling Potential ◽  
Stabilization Method ◽  
Swell Potential ◽  
Main Factor

The main factor that governs the shrink-swell behavior of expansive soils is the change in water content and the amount and type of clay size in the soil. In this paper, the research made are focused in reducing the swell potential of the studied clay by improvement in two ways: first by stabilization with a combination of eco-cement and Portland cement (1:1 ratio), and second by synthetic fiber reinforcement. A series of laboratory tests were performed on synthetic fiber reinforced expansive soil to determine the potential for using synthetic fiber reinforcement to reduce swell potential of soils. Specimens tested were prepared at two different synthetic fiber dosages 0.2% and 0.4%. The treatment of expansive clay with 5% eco-cement and 5% Portland cement revealed a better improvement of the swelling potential. The synthetic fiber reinforcement of the expansive soil doesn’t lead to a significant improvement of the soil.

scholarly journals Bearing Capacity Improvement of Expansive Soil: Stabilization with Cement and Iron Oxide Additive

2020 ◽  
Vol 331 ◽  
pp. 02005
Author(s):  
Sofwan ◽  
Sukiman Nurdin
Keyword(s):  
Iron Oxide ◽  
Bearing Capacity ◽  
Soil Stabilization ◽  
Expansive Soil ◽  
Expansive Clay ◽  
Test Results ◽  
Swelling Potential ◽  
Oxide Additive ◽  
Volume Increment ◽  
Capacity Improvement

This research is intended to increase the bearing capacity and durability of expansive clay subgrade with Portsoil Composite Cement (PCC) and Iron Oxide additives. Using two variants of the stabilization material composition; composition-1 is soil with 5% of PCC, and composition-2 is soil with 5% PCC + 0. 04% Iron Oxide). Tests include swelling potential, durability, and CBR (California Bearing Ratio). The test results showed that the performance of stabilization using composition-2 was able to reduce swelling potential on day 3 by 94. 44% (14. 44% greater than using composition-1), reducing the potential for volume increment by 94. 15% (greater 15. 02% compared to using composition-1) and weight to 93. 31% (15. 32% greater than using first). The highest CBR value in the 3 wet-dry cycle periods was nature soil 2. 32%, using composition-1 reached 25. 26%, while using composition-2 reached 36. 93% (11. 67% greater than CBR value using composition-1). That the addition of 0. 04% Iron Oxide to PCC-soil stabilization can significantly improve cement performance for expansive clay stabilization as a road subgrade.

An Overview: to Reduce Swelling Potential of Expansive Soil By Using Polypropylene Material

2018 ◽  
pp. 129-131
Author(s):  
A. A. Musale ◽  
M. A. Mhetre ◽  
A. I. Mukeri ◽  
K. S. Chavan ◽  
R. N. Kawade ◽  
...  
Keyword(s):  
Expansive Soil ◽  
Swelling Potential ◽  
Polypropylene Material

scholarly journals Speech rhythm: a metaphor?

2014 ◽  
Vol 369 (1658) ◽  
pp. 20130396 ◽  
Author(s):  
Francis Nolan ◽  
Hae-Sung Jeon
Keyword(s):  
Traditional View ◽  
Time Intervals ◽  
Speech Rhythm ◽  
Linguistic Structure ◽  
Regular Time ◽  
Linguistic Functions ◽  
Absence Of Evidence ◽  
Metaphorical Extension ◽  
Analogical Process

Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep ‘prominence gradient’, i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a ‘stress-timed’ language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow ‘syntagmatic contrast’ between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence of alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and it is this analogical process which allows speech to be matched to external rhythms.

Processing and Excellent Oxidation Resistance of Nanocrystalline Fe-Cr Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 1122-1125
Author(s):  
Rajeev K. Gupta ◽  
B.V. Mahesh ◽  
R.K. Singh Raman ◽  
Carl C. Koch
Keyword(s):  
Oxidation Resistance ◽  
Secondary Ion Mass Spectrometry ◽  
Nanocrystalline Alloy ◽  
High Energy ◽  
Processing Route ◽  
Protective Oxide ◽  
Time Intervals ◽  
Regular Time ◽  
Order Of Magnitude ◽  
Energy Ball

Nanocrystalline and microcrystalline Fe-10Cr alloys were prepared by high energy ball milling followed by compaction and sintering, and then oxidized in air for 52 hours at 400°C. The oxidation resistance of nanocrystalline Fe-10Cr alloy as determined by measuring the weight gain after regular time intervals was compared with that of the microcrystalline alloy of same chemical composition (also prepared by the same processing route and oxidized under identical conditions). Oxidation resistance of nanocrystalline Fe10Cr alloy was found to be in excess of an order of magnitude superior than that of microcrystalline Fe10Cr alloy. The paper also presents results of secondary ion mass spectrometry of oxidized samples of nanocrystalline and microcrystalline Fe-Cr alloys, evidencing the formation of a more protective oxide scale in the nanocrystalline alloy.

A Method for Quantitative Analysis of the Kinematics of Fibroblast Migration in a Monolayer Wound Model

2011 ◽  
Author(s):  
Gil Topman ◽  
Orna Sharabani-Yosef ◽  
Amit Gefen
Keyword(s):  
Wound Healing ◽  
Cell Migration ◽  
Wound Healing Assay ◽  
Complete Coverage ◽  
Time Intervals ◽  
Fibroblast Migration ◽  
Wound Model ◽  
Regular Time

A wound healing assay is simple but effective method to study cell migration in vitro. Cell migration in vitro was found to mimic migration in vivo to some extent [1,2]. In wound healing assays, a “wound” is created by either scraping or mechanically crushing cells in a monolayer, thereby forming a denuded area. Cells migrate into the denuded area to complete coverage, and thereby “heal” the wound. Micrographs at regular time intervals are captured during such experiments for analysis of the process of migration.

scholarly journals Using approximate Bayesian inference for a “steps and turns” continuous-time random walk observed at regular time intervals

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8452
Author(s):  
Sofia Ruiz-Suarez ◽  
Vianey Leos-Barajas ◽  
Ignacio Alvarez-Castro ◽  
Juan Manuel Morales
Keyword(s):  
State Space ◽  
Continuous Time ◽  
Time Scale ◽  
Animal Movement ◽  
State Space Model ◽  
Movement Direction ◽  
Time Intervals ◽  
Space Model ◽  
Regular Time ◽  
Approximate Bayesian

The study of animal movement is challenging because movement is a process modulated by many factors acting at different spatial and temporal scales. In order to describe and analyse animal movement, several models have been proposed which differ primarily in the temporal conceptualization, namely continuous and discrete time formulations. Naturally, animal movement occurs in continuous time but we tend to observe it at fixed time intervals. To account for the temporal mismatch between observations and movement decisions, we used a state-space model where movement decisions (steps and turns) are made in continuous time. That is, at any time there is a non-zero probability of making a change in movement direction. The movement process is then observed at regular time intervals. As the likelihood function of this state-space model turned out to be intractable yet simulating data is straightforward, we conduct inference using different variations of Approximate Bayesian Computation (ABC). We explore the applicability of this approach as a function of the discrepancy between the temporal scale of the observations and that of the movement process in a simulation study. Simulation results suggest that the model parameters can be recovered if the observation time scale is moderately close to the average time between changes in movement direction. Good estimates were obtained when the scale of observation was up to five times that of the scale of changes in direction. We demonstrate the application of this model to a trajectory of a sheep that was reconstructed in high resolution using information from magnetometer and GPS devices. The state-space model used here allowed us to connect the scales of the observations and movement decisions in an intuitive and easy to interpret way. Our findings underscore the idea that the time scale at which animal movement decisions are made needs to be considered when designing data collection protocols. In principle, ABC methods allow to make inferences about movement processes defined in continuous time but in terms of easily interpreted steps and turns.

scholarly journals The Use of Geogrids in Mitigating Pavement Defects on Roads Built over Expansive Soils

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Richard Shumbusho ◽  
Gurmel S. Ghataora ◽  
Michael P.N. Burrow ◽  
Digne R. Rwabuhungu
Keyword(s):  
Seasonal Changes ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Real Field ◽  
Experimental Program ◽  
Swelling Potential ◽  
Swelling Behaviour ◽  
Wetting And Drying ◽  
Potential Benefits

This study was conducted to investigate the potential benefits of using geogrids in mitigating pavement defects notably roughness and longitudinal cracking on pavements built over expansive soils. The seasonal changes of expansive soils (periodic wetting and drying) cause detrimental effects on the overlying road pavements. Such detrimental behavior of expansive soils was simulated in a controlled laboratory environment through allowing cyclic wetting and drying of an expansive soil underlying a pavement section. The shrink/swell effects of the expansive soil subgrade were examined through monitoring its change in moisture, and measuring deformation of overlying pavement section. The experimental study suggested that a geogrid layer in a reinforced pavement section can reduce surface differential shrinking and swelling deformation resulting from underlying expansive soils by a factor of 2 and 3 respectively in comparison to unreinforced section. Given that an oedometer test which is typically used to predict swelling potential of expansive soils is known to overpredict in-situ soil swell, experimental program also investigated quantitatively the extent to which the oedometer can overestimate swelling behaviour of the real-field scenarios. It was found that oedometer percent swell can overpredict in-situ swelling behaviour of the expansive soil by a factor ranging between 2 and 10 depending upon the period over which the in-situ expansive soil has been in contact with water.

scholarly journals PENGUJIAN TANAH EKSPANSIF DENGAN SKALA MODEL MENGGUNAKAN KAYU DOWEL SEBAGAI PENGGANTI DINDING PENAHAN TANAH

2020 ◽  
Vol 3 (3) ◽  
pp. 853
Author(s):  
Richard Samuel ◽  
Alfred Jonathan Susilo
Keyword(s):  
Water Content ◽  
Pile Foundation ◽  
Expansive Soil ◽  
Lateral Movement ◽  
Swelling Properties ◽  
Important Thing ◽  
Shrinkage Potential

Foundation is one of the most important thing in a construction. The frequently used foundation in construction is pile foundation. In Indonesia  the used of pile is adapt by the condition and quality of the soil. Indonesia had many types of soil, and one of them is expansive soil. Expansive soil is a type of clay that had a swelling and shrinkage potential where the swelling happen when the water content is increase and shrink when the water content decreased. One of the mineral that can cause swelling is montmorillonite mineral in expansive soil. The chemical chain between particles that influenced by the increase of water content is causing montmorillonite mineral to swell. The focus of this research is lateral movement that happened to pile as an effect of the swelling properties in expansive soil. This analysis will also inform the effectiveness on using different size and number of pile in expansive soil. Fondasi merupakan salah satu bagian terpenting dalam suatu konstruksi. Salah satunya yang sering digunakan pada proses pelaksanaan konstruksi adalah fondasi tiang pancang. Di Indonesia sendiri penggunaan fondasi tiang pancang disesuaikan dengan kondisi dan kualitas dari tanah yang ada. Indonesia memiliki berbagai macam tipe dan jenis tanah yang berbeda, salah satunya adalah tanah ekspansif. Tanah ekspansif merupakan jenis lempung yang memiliki daya pengembangan dan penyusutan dimana pengembangan tersebut terjadi jika adanya penambahan kadar air dan menyusut ketika terjadi pengurangan kadar air. Salah satu yang dapat menjadi penyebab terjadinya pengembangan adalah kandungan mineral montmorillonite yang terdapat pada tanah ekspansif. Ikatan kimia antar partikel yang dipengaruhi oleh adanya peningkatan kadar air tanah menyebabkan mineral montmorillonite pada tanah ekspansif tersebut akan mengembang. Analisis yang dilakukan akan berfokus pada pergeseran lateral yang terjadi pada  tiang pancang sebagai akibat dari dampak pengembangan yang terjadi pada tanah ekspansif. Analisis ini juga menghasilkan efektivitas pada penggunaan ukuran dan jumlah tiang pancang ditanah ekspansif.

scholarly journals Automatic Target Acquisition and Bull Tracker using Gps and Gsm Technology

2020 ◽  
Vol 9 (3) ◽  
pp. 2776-2779
Keyword(s):  
Real Time ◽  
Mobile Application ◽  
Tracking System ◽  
Target Acquisition ◽  
Time Intervals ◽  
Regular Time ◽  
Arduino Microcontroller

An efficient bull tracking system is designed and implemented for tracking the movement of any bull from any location at any time. The designed device works using GPS and GSM technology for bull tracking. Arduino microcontroller is used to control the GPS and GSM module. The device is embedded on a bull whose position is to be determined and tracked in real time. The microcontroller is used to control the GPS module to get the coordinates at regular time intervals. The GSM module is used to transmit the updated coordinates of bull location to the client via SMS and mobile application. When the SMS is received, the app will automatically read the SMS and update the location of the bull to the user. This device will help the user to always keep an eye on their bull.

Sign in / Sign up

Export Citation Format

Share Document