scholarly journals Application of Calculus of Variation in the Optimization of Functional Parameters of Compacted Modified Soils: A Simplified Computational Review

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Kennedy C. Onyelowe

Fixed endpoint problems (FEPPs) in constrained systems like the effect of curing time or the effect of certain additives in soil stabilization operations have been reviewed illustratively for sustainability purposes in geotechnics. The calculus of variation (CoV) technique of Hamilton’s problem was demonstrated using a typical case in geotechnics; the effect of curing time on the unconfined compressive strength of expansive soils is utilized as foundation materials. The era of smart technologies is evolving, and to key into this fast-moving area to help the field of geotechnics, it is required that these new areas are deployed to study their usefulness. The use of CoV in modeling or simulating geotechnical properties of soil behavior is not prominent and has been played down due to the uncertainties surrounding it. However, this work has identified that if any geotechnical system can be demonstrated in graphs, then the use of CoV becomes easy with the mathematical concept that curves are elements of straight paths. The results of this work show that CoV is a powerful tool to achieving sustainable optimization of quality properties of stabilized for sustainable and optimal materials handling, design, and construction.

2019 ◽  
Vol 7 (1) ◽  
pp. 27-36
Author(s):  
Nadiia Kopiika ◽  
Yuriy Petrenko

The purpose of the study is to conduct thorough theoretical research and literature overview regarding possible ways of soil stabilization on the basis of this practice increasing demand. In particular an emphasis is made on the chemical technique for weak soils strengthening, due to its prevalence and various practical and economic advantages. Great amount of promiscuous data was analyzed and organized; in addition on its basis an attempt is made to provide convincing calculation technique for further usage in engineering soils` stabilization practice. Besides, various factors which could influence on the results` accuracy are identified with corresponding recommendations for further possible research on this issue.


2019 ◽  
Vol 19 (1) ◽  
pp. 21-30
Author(s):  
Arifudin Nur ◽  
Suryo Hapsoro Tri Utomo ◽  
M. Zudhy Irawan

Abstract Expansive soils have high swelling and shrinkage potentials, which may cause damage to road structures. Therefore, stabilization is required. One method of stabilization is to use lime and spent catalysts with the aim of increasing carrying capacity and reducing swelling. Spent catalyst is a petroleum processing waste and classified as pozzolanic material. The addition of lime and spent catalysts can increase the CBR value and reduce swelling of soils. The results of this study indicate that the maximum increase in soaked CBR and unsoaked CBR values occurred in soil mixtures with optimum lime content and 12% spent catalyst with 7 days of curing. While the soil mixture with optimum lime content and 12% spent catalyst, with 7 days of curing, is the best mixture that produces soaked CBR value of 49.67%, swelling of 0.15%, and plasticity index value of 11.97%, so the soil meets the requirements to be used as pavement subgrade. Keywords: expansive soil, stabilization, road structure, subgrade, road pavement  Abstrak Tanah ekspansif memiliki potensi pengembangan dan penyusutan yang tinggi, sehingga dapat menyebabkan kerusakan struktur jalan. Oleh sebab itu, perlu dilakukan stabilisasi. Salah satu metode stabilisasi adalah menggunakan kapur dan spent catalyst dengan tujuan meningkatkan kapasitas dukung dan menurunkan swelling. Spent catalyst merupakan limbah pengolahan minyak bumi dan termasuk bahan pozzolan. Penam-bahan kapur dan spent catalyst mampu meningkatkan nilai CBR dan mereduksi swelling. Hasil studi ini menunjukkan bahwa peningkatan maksimum nilai CBR soaked maupun CBR unsoaked terjadi pada campuran tanah dengan kadar kapur optimum dan 12% spent catalyst dengan peraman 7 hari. Sedangkan campuran tanah dengan kadar kapur optimum dan 12% spent catalyst, dengan peraman 7 hari, merupakan campuran terbaik yang menghasilkan nilai CBR soaked sebesar 49,67%, swelling sebesar 0,15%, dan nilai indeks plastisitas sebesar 11,97%, sehingga tanah memenuhi syarat untuk digunakan sebagai tanah dasar perkerasan jalan. Kata-kata kunci: tanah ekspansif, stabilisasi, struktur jalan, tanah dasar, perkerasan jalan


2020 ◽  
Vol 998 ◽  
pp. 323-328
Author(s):  
Achmad Bakri Muhiddin ◽  
Marthen M. Tangkeallo

In remote areas, most roads still use pavements that are very sensitive to climate change, especially those using clay pavements with high plasticity. In addition to the issue of cost, the difficulty of obtaining a proper source of material is another problem that has led to soaring prices for materials. In this regard, a study was conducted using local materials, namely zeolite as a stabilizing material added with waterglass as activating agent. The research began with samples of laterite soil and natural zeolite for XRD test (microstructure testing), and then testing for laterite soil’s index properties and engineering properties, namely Unconfined Compressive Strength and CBR value. The purpose of the test is to determine the correlation between the Unconfined Compressive Strength (UCS) and the soil bearing capacity (CBR) caused by adding zeolite as stabilizer material and waterglass as activator with increasing curing time. Laterite soils contain a brownish red iron oxide. The stabilizing material zeolite contains a crystalline mineral of alumina silicate SiO2. While waterglass composed of sodium meta silicate. Stabilization carried out by mixing 4%, 8%, 12%, 16%, and 20% of zeolite with addition of 2% waterglass, percentage was measured based on soil dry weight. Specimens were tested at curing time of 0, 7, 14, and 28 days. The test result shows increasing UCS and CBR values with increasing percentage of zeolite. At mix of 20% zeolite and 2% waterglass, the unconfined compressive strength reaches 23.54 kg/cm2 with CBR value 58% at 28 days of curing time.


Author(s):  
Raju Acharya ◽  
Aravind Pedarla ◽  
Tejo V. Bheemasetti ◽  
Anand J. Puppala

Expansive soil embankments are prone to shallow slope failures caused by associated swell–shrink movements. Previous studies have confirmed that seasonal changes and corresponding volumetric changes are responsible for desiccation cracking, which is a major factor behind shallow slope failures of highway embankments. For the past few years, soil stabilization proved to be an effective way to mitigate the swell–shrink property of expansive clays. The current study addresses the feasibility of guar gum biopolymer in mitigating the swell–shrink behavior of clays and in turn making it possible to adopt them as stable geomaterials. The sustainable benefits of biopolymers far exceed the environmental benefits from conventional stabilizers that contractors typically use. This paper presents a comprehensive laboratory study, followed by finite difference modeling analysis, on biopolymeric guar gum–remediated expansive soils collected from shallow slope failure-prone areas. For this study, two dam locations, at Grapevine Lake and Joe Pool Lake, Texas, that were originally constructed with expansive soils, were considered. The engineering performance of biopolymer-treated soils was evaluated and an optimum dosage was recommended for mitigating desiccation cracking at the test sites. Slope stability analyses were conducted using Fast Lagrangian Analysis of Continua in Three Dimensions software by adopting laboratory-determined strength parameters to determine the range of the factor of safety for the slopes. The variation of the factor of safety computed with the inclusion of enhanced engineering parameters from guar gum treatments revealed the advantages of adopting this treatment.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3058
Author(s):  
Julia Rosales ◽  
Francisco Agrela ◽  
José Ramón Marcobal ◽  
José Luis Diaz-López ◽  
Gloria M. Cuenca-Moyano ◽  
...  

Stabilization is a traditional strategy used to improve soils with the main objective of ensuring that this base is compliant with the technical specifications required for the subsequent development of different infrastructures. This study proposes the use of commercial nanomaterials, based on a solution of silicates, to improve the technical characteristics and bearing capacity of the expansive soil. A physical–chemical property study was carried out on the additive nanomaterial. Subsequently, different mixtures of expansive soil, selected soil and artificial gravel with quicklime and commercial nanomaterials were developed to evaluate the improvement obtained by the use of nanomaterials in the technical characteristics of the soil. Compressive strength and the Californian Bearing Ratio index were considerably increased. A full-scale study was carried out in which the nanomaterial product was applied to two different sections of stabilized road compared to a control section. The results obtained showed that the use of nanomaterial led to the possibility of reducing the control section by 30 cm, thus achieving less use of quicklime and a mechanical means for preparing the road section. The use of commercial nanomaterial improved the behavior of the stabilized sub-base layer. Through life cycle assessment, this study has shown that the use of nanomaterials reduces the environmental impact associated with soil stabilization.


2019 ◽  
Vol 276 ◽  
pp. 05005
Author(s):  
Wawan Kuswaya ◽  
Wahyudi Marsiano ◽  
Syafalni Syafalni ◽  
Jonbi

The need for a pavement matrix in road construction, especially in Sumatra area, is now more difficult and expensive because the deposit materials are concentrated in Java and most of them are not available. For this reason, soil stabilization is a way out of this problem. On this basis it is necessary to conduct stabilization research with highly active stabilization material by using Portland cement type I. The soil to be stabilized is clay soil which is derived from the areas of Jambi and Palembang and which has a low CBR value less than the requirement for sub base or pavement (< 10%), with the expected CBR value of stabilization to be suitable for road construction. This research covers physical and soil mechanical properties which are compaction parameter and CBR value with 3 days of dry curing time and 4 days of soak curing time using ASTM test procedure. Variations of cement addition were used of 6%, 8%, and 10% for the clay soil from Palembang and 8%, 10%, and 12% for the clay soil from Jambi, by percentage of dry weight of the sample test. The results of this study showed that the CBR value significantly increased with the addition of cement, with Palembang soil CBR value rising from 3.46% to 130.74% and Jambi soil CBR value rising from 7.20% to 206.43% respectively.


2014 ◽  
Vol 21 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Ismail Zorluer ◽  
Suleyman Gucek

AbstractThe use of waste materials as an additive in soil stabilization has been widespread. This is important in terms of recycling of waste materials and reducing environmental pollution. The objective of this study is to investigate the beneficial reuse of marble dust and fly ash in soil stabilization. Tests were performed on clay soil mixtures amended with marble dust and fly ash. Marble dust was used as an activator due to fly ash being inadequate for self-cementing. Unconfined compressive strength (qu), freeze-thaw, swelling, and California bearing ratio (CBR) tests were conducted to investigate the effect of marble dust and fly ash, curing time, and molding water content on geotechnical parameters. Addition of marble dust and fly ash increased unconfined compressive strength, CBR, and freeze-thaw strength, but these additives decreased swelling potential and grain loss after freeze-thaw. Increasing the curing time results in increased strength of mixtures and decreased grain loss. As a result, this study shows that the geotechnical properties of clay soil are improved with the addition of marble dust and fly ash. This is an economical and environmentally friendly solution.


2021 ◽  
Vol 7 (1) ◽  
pp. 40-48
Author(s):  
Noor Dhani ◽  
Ahmad Gasruddin ◽  
Hartini Hartini ◽  
La Baride

Soft soil was one of the most widely encountered problems in construction, especially for archipelago countries which most of its area was lowland with a high deposit of soft soil. To overcome this problem, soil stabilization was one of the most widely used as a solution. Soil stabilization in general uses chemical substances that are classified as pozzolan material. Pozzolan material uses its capability to strengthen the cohesion of soil grains. Mostly, pozzolan material consists of silica. Overboulder asbuton and zeolite were examples of natural pozzolan material in Indonesia. Both materials have a high silica content. Thus, the author interested to figure out the mechanical behavior of these two substances as a soil stabilizer. This research was a correlating study to the previous paper with the same author which discusses the overboulder asbuton as a soil stabilizer. Overboulder added to the mix is determined as 15%, with varied zeolite percentages applied to examine the differences. The UCT was conducted according to ASTM D-2166 as a parameter. As the standard remolding method, a standard proctor test was conducted to determine the optimum moisture content and the maximum density of each mix. While the UCT specimens were tested at the certain curing time for each composition. The curing time applied was 0, 7, 14, and 28 days. By this curing period, the effective pozzolanic reaction that occurs for each composition could be determined. The result shows that zeolite addition to overboulder asbuton could increase the soil density and increase its compressive strength. It is indicated that overboulder asbuton and zeolite mix could be a proper alternative as a soil stabilizer. Doi: 10.28991/cej-2021-03091635 Full Text: PDF


Author(s):  
G. M. Levenko

When designing or reconstructing buildings and structures on the swelling soils, it is necessary to be particularly concerned about the pattern of these soils behavior in order to subsequently be able to predict the behavior of the ‘basement – foundation – building’ system. The most effective way to stabilize soil behavior of the basement contaminated with industrial effluents is injection methods used for stabilization. The main task of soil chemical stabilization is to strengthen the bonds between soil particles with the help of chemical reagents. As a result of the research, the design parameters for foundations stabilization of soils composed contaminated with peroxy acid were determined. Depending on the concentration of peroxy acid in the soil and the density of the used sodium silicate solution, the limiting values initial components volume ratios were determined to carry out qualitative and reliable soil stabilization for the basements.


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