Soil Stabilization Methods Research Articles

Use of rice husk ash as a stabilizer to reduce soil loss and runoff rates on sub-base materials of forest roads from rainfall simulation tests

The impact of rice husk ash (RHA) as a stabilizer to reduce soil loss and surface runoff rates on sub-base materials of forest roads has been studied using a portable rainfall simulator at an intensity of 52mmh−1. Thirty rainfall simulations were carried out on different combinations of materials: on the natural sub-base soils (5), on the materials stabilized with pure lime (5), and on the materials stabilized with different percent of RHA and lime (20). Results indicated that on natural sub-base soils, the runoff coefficient was 53.6% and mean time to runoff was 87s. On the materials stabilized with pure lime, the runoff coefficient and mean time to runoff were measured 58.7% and 63s, respectively. The lowest runoff coefficient was measured 36.6% on the combination of soil+6% lime+9% RHA. However, the highest mean time to runoff was recorded 198s on the combination of soil+4% lime+9% RHA. The maximum and minimum soil loss rates were found on the natural sub-base soils (212.2gm−2) and on the combination of soil+6% lime+9% RHA (162.4gm−2), mainly due to changes in maximum dry density (MDD), plasticity index (PI), optimum moisture content (OMC) and CBR of materials. On the basis of the results, we concluded that the rice husk ash not only increases the materials quality in soil stabilization methods with lime, but also reduces the runoff and soil loss rates on unpaved forest roads.

The Effect of Diesel Fuel Pollution on the Efficiency of Soil Stabilization Method

Chemical soil stabilization method can be applied as a remediation technique for contaminated soils. Since stabilization method can improve the soil geotechnical properties, the effect of contamination should be investigated on soil strength improvement with this method. This paper studies the effect of different additives such as lime, cement, rice husk ash and RRP-235 Special on the geotechnical properties of a diesel fuel contaminated kaolinite. A series of unconfined compressive strength and direct shear tests were performed on the contaminated kaolinite stabilized with additives in the amounts of 1, 3 and 5% by soil dry weight. Results showed that an increase in diesel fuel as contaminant up to 10% by dry weight of the soil had adverse effects on lime and rice husk ash stabilized soil strength and cohesion, while it increased the strength and cohesion of cement stabilized soil. The friction angle of all the lime, cement and rice husk ash stabilized samples was decreased with increasing the contaminant. An increase in RRP-235 Special had no impact on the soil strength properties.

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation.

We have developed a novel method to synthesize a hyper-branched biomimetic hydrogel network across a soil matrix to improve the mechanical strength of the loose soil and simultaneously mitigate potential contamination due to excessive ammonium. This method successfully yielded a hierarchical structure that possesses the water retention, ion absorption, and soil aggregation capabilities of plant root systems in a chemically controllable manner. Inspired by the robust organic-inorganic composites found in many living organisms, we have combined this hydrogel network with a calcite biomineralization process to stabilize soil. Our experiments demonstrate that poly(acrylic acid) (PAA) can work synergistically with enzyme-induced carbonate precipitation (EICP) to render a versatile, high-performance soil stabilization method. PAA-enhanced EICP provides multiple benefits including lengthening of water supply time, localization of cementation reactions, reduction of harmful byproduct ammonium, and achievement of ultrahigh soil strength. Soil crusts we have obtained can sustain up to 4.8 × 103 kPa pressure, a level comparable to cementitious materials. An ammonium removal rate of 96% has also been achieved. These results demonstrate the potential for hydrogel-assisted EICP to provide effective soil improvement and ammonium mitigation for wind erosion control and other applications.

The Potential of Soft Soil Improvement Through a Coupled Technique Between Electro Kinetic and Alkaline Activation of Soft Soil

Soil stabilization techniques have been in development for decades with different rates of success. Alkaline activation of soft soil is one of those techniques that has proved to deliver some of the best shear strength values with minor drawbacks in comparison with conventional soil stabilization methods. However, environmental considerations have not been taken into account, as major mineral glassy phase activators are poisoning alkaline solutions, such as sodium-, potassium-hydroxide, and sodium-, potassium-silicate, which poses serious hazards to man and environment. This paper addresses the ways of discarding the involvement of the aforementioned alkaline solutions in soft soil stabilization by investigating the potential of a coupled electro kinetic alkaline activation technique for soft soil strengthening, through which the provision of alkaline pH is governed by electro kinetic potential. Uncertainties in regard to the dissolution of aluminosilicate as well as the dominance of acidic front are challenges that need to be overcome.

Effect of “A Polyurethane Mastic” on Shear Strength of Gypsiferous Soil

The importance of decreasing the cost of soil structures due to the budget constraints makes engineers avoid handling large volumes of soil, thus making maximum use of local materials. Soil performance change in order to improve engineering applications of soil is called soil stabilization. Soil stabilization methods can be mechanical, electrical, thermal, chemical, etc. Gypsiferous soil including soils used in civil affairs and special structures in the vicinity of water needs to be established. This study is conducted to evaluate changes of shear strength of gypsiferous soil, using chemical method by addition of “A polyurethane Mastic”. The studied gypsiferous soil was prepared from 3km northwest of Ramhormoz in Khuzestan province. Soil samples containing 0%, 1%, 2%, 3%, 5% and 7% of the said material additive were compressed with optimum moisture content obtained from standard Procter test, and finally, were tested under the direct shear test at shear rate of 0.5 mm per minute. After achieving cohesion parameters of soil, the best mix of the additive “A polyurethane Mastic” was found to be 5%.

Review on Stabilization of Clayey Soil UsingFines Obtained From Demolished ConcreteStructures

Soil stabilization may be defined as the process of changing soil engineering properties to improve the bearing capacity and durability property of weak soil. The aim of the study was to review on stabilization of clayey soil using demolished waste material. Various methods are available for stabilizing clayey soil. These methods include stabilization with chemical additives, soil replacement, compaction control, moisture control and thermal methods. All these methods may have the disadvantages of being ineffective and expensive. Based on literature fines obtained from demolished waste is a low cost and effective soil stabilization method.

THE USE OF LOGIT MODEL FOR DESIGNING MIXTURES OF SOILS STABILIZED WITH HYDRAULIC BINDERS

Certain soils encountered in practice are difficult or impossible to use for road building. To improve their mechanical properties, various methods of soil stabilization are applied. A widely used means of soil stabilization is the addition of hydraulic binders. In the methodology of designing of soil-binder mixtures it is important to determine how, based on variable parameters characterizing a sample of soil, to predict the grade of the binder and the quantity in which it is to be added to the soil in order for defined requirements to be met. This work describes an application of statistical logit model in designing soil-binder mixtures intended to be used for road foundations, subject to defined requirements as to their strength and frost resistance.

海水環境下におけるセメント処理した有明粘土の劣化の進行に関する検討

In construction, chemical soil stabilization method, such as adding cement and quick lime has been often applied to increase the strength of soft ground and surplus soil. However, in some specific natural environments, such a stabilization method may cause significant reduction of the strength of treated-soil. In this paper, Ordinary Portland cement was used as a stabilizer for examining the durability of chemical stabilized Ariake clay under seawater condition. In order to prepare deteriorated specimens, original Ariake clay was mixed with different contents of cement (50, 70, 100kg/m3) and immersing artificial seawater with different NaCl concentration (10, 20, 30g/L). The deterioration progress of cement-treated Ariake clay was investigated by using the micro cone penetration test. It is shown from the test results that the deterioration of cement-treated soil progresses in proportion to square root of seawater contacting duration. In addition, an empirical prediction formula of deterioration rate of cement-treated Ariake clay considering effect of Mg ion concentration in seawater and water-cement ratio in the treated soil is proposed according to experimental results.

Experimental study on stabilization of a low plasticity clayey soil with cement/lime

One of the possible problems that may be encountered by execution of future projects such as highway, mass construction, and also industrial buildings in Farmahin (in the northwestern of Arak, Iran) is low strength and large deformation of the field soil. Such soils can be treated with the general traditional soil stabilization methods such as lime or cement stabilization methods. In the current study, the effects of two types of additive for the soil (i.e., lime/cement) on the geotechnical and engineering properties of the soil are studied. The results of the study indicate that optimum moisture content, maximum dry unit weight, and plasticity index are affected by the addition of cement or lime. Also cement treatment results in increase of unconfined compressive strength (UCS) of the soils significantly, whereas the test results indicate that there is an optimum of lime content so that the addition of a few percentage of lime results in increase of unconfined compressive strength. Generally, improvement in mechanical behaviors of the soil due to cement treatment was noticeably higher than lime treatment. Also the results of tests show that the change of UCS of the specimens with the initial water content and curing time is significant, so that decreasing of initial water content or increasing of curing time results in increase of USC of the specimens. Also, the current study sought to characterize the relationship between secant modulus (E50) and UCS, curing time, and cement or lime content.

The Potentials of Portland Cement and Bitumen Emulsion Mixture on Soil Stabilization in Road Base Construction

Recycled road based material requires a stabilizing effect in order to provide a longer life to pavements. This is done by improving its strength and reduces its water vulnerability. One of the most popular techniques to achieve this is by using soil stabilization. This research aims to analyze in details the soil stabilization method which utilizes Portland cement and bitumen emulsion in improving soil properties. As a result, this will increase the pavement bearing capacity (conducted via laboratory research). The combination of Portland cement and bitumen emulsion are beneficial for the purpose of increasing the stiffness and also the elasticity of soil stabilized layer. In order to examine this, two steps were undertaken, first, by examining the Unconfined Compressive Strength (UCS) and Modulus of Elasticity (ME) on samples mixed with soil aggregates comprising Portland cement and bitumen emulsion. Next, the data collated was analysed and the graph plots were presented as to show the optimum value of Portland cement and bitumen emulsion used in soil stabilization. The major findings of this research showed the importance of soil stabilization using Portland cement and bitumen in improving pavement’s performances by increasing bearing capacity of its layer. The findings revealed that overall; the optimum value of Portland cement and bitumen emulsion utilized in base Soil stabilization method is 3% and 3% respectively. With this method, the duration time of the project can be reduced and subsequently the project cost may be also reduced.

PENGENALAN STABILISASI TANAH DENGAN JET GROUTING

Due to restriction of land availability it is frequently we have to build constructions on soft or low bearingcapacity soils, so that soil stabilization must be applied in order to increase its properties. There are manytechniques of soil stabilization, where its applicability depends on many factors regarding appropriateengineering judgement. This paper presents the soil stabilization method by jet grouting, including its theory andpractice.

Carbonating magnesia for soil stabilization

This paper investigates the potential for carbonating reactive magnesia (MgO) to serve as a more sustainable soil stabilization method by providing rapid and significant strength development of the stabilized soil through absorbing substantial quantities of CO2. Gaseous CO2was forced through laboratory-prepared reactive MgO-treated soil samples in a triaxial cell set-up, and their resulting mechanical and microstructural properties were investigated using unconfined compressive strength, X-ray diffraction, and scanning electron microscopy. The results showed that adequately carbonated MgO-treated soils could, in a few hours, reach a similar strength range to corresponding 28 day Portland cement (PC)-stabilized soils. Hydrated magnesium carbonates, namely nesquehonite and hydromagnesite–dypingite, were the main products of the carbonated MgO in the soil, and were responsible for the significant strength development.

Cementation of sand soil by microbially induced calcite precipitation at various degrees of saturation

A newly emerging microbiological soil stabilization method, known as microbially induced calcite precipitation (MICP), has been tested for geotechnical engineering applications. MICP is a promising technique that utilizes the metabolic pathways of bacteria to form calcite precipitation throughout the soil matrix, leading to an increase in soil strength and stiffness. This paper investigates the geotechnical properties of sand bio-cemented under different degrees of saturation. A series of laboratory experiments was conducted, including sieve analysis, permeability, unconfined compressive strength, consolidated undrained triaxial, and durability tests. The results indicate that higher soil strength can be obtained at similar CaCO3 content when the treatment is performed under a low degree of saturation. The experimental results are further explained with a mathematical model, which shows that the crystallization efficiency, i.e., actual volume of crystals forming at the contact point where they contribute the most to strength, can be calculated from the degree of saturation and grain size. Fine sand samples exhibited higher cohesion, but lower friction angle than coarse sand samples with similar CaCO3 content. The results also confirm the potential of MICP as a viable alternative technique for soil improvement in many geotechnical engineering applications, including liquefiable sand deposits, slope stabilization, and subgrade reinforcement. The freeze–thaw and acid rain resistance of MICP-treated sand has also been tested.

Reinforcement Effect of Recycled Plastic Piles on Bearing Capacity of Shallow Ground

In general, in cases when the shallow ground is soft, a method of surface soil stabilization is adopted. However, problems regarding surface soil stabilization often arise. There are a lack of guaranty regarding construction quality, dispersion of the solidification material, prolonging of the curing time, operating efficiency at the time of disassembly and anxiety concerning the workability of clear and leaching of hexavalent chromium. We've developed an alternative method of surface soil stabilization in which the recycled plastic piles are driven under the foundation in fixed intervals. The piles are manufactured from material recovered by The Containers and Packaging Recycling Law and the remnants from a plastic factory. The main ingredients are polypropylene and polystyrene. The end of the pile is cone-shaped, and the axis is not hollow but filled with plastic. To verify the reinforcement effect on the composite ground by the pile, two loading tests were executed. They consisted of pushing and pulling tests of the pile, and pushing tests of the plate. In order to verify the durability of the recycled plastic piles under the ground, age acceleration tests in the laboratory and aging degradation tests of the exposed specimens were performed. The main findings of the loading tests and the durability tests are as follows : (1) The bearing capacity of the ground driven piles was more than matched that of the separate ground and piles. (2) The bearing capacity of the pile was calculated from The Swedish Weight Sounding Test and the bearing capacity of the ground driven piles were able to be evaluated by a reinforcement coefficient of 1.6. (3) The recycled plastic piles satisfied all criteria on durability tests, and no deterioration on the molecular level was confirmed.

Instability Analysis of Damaged Pile Due to Static or Dynamic Overload

Instability of a damaged pile due to a statically or dynamically applied overload is studied in this work using the finite element method. A damage parameter from such a pile is calculated using fracture mechanics concepts. The parameter is used to modify the beam element at the cracked or damaged location. Soil samples were obtained from the site of the pile and were subjected to laboratory tri-axial tests to obtain shear strength parameters c and . Other soil parameters such as Young’s modulus E and Poisson’s ratio were also obtained from the tri-axial tests. These were used to calculate shear strength and sub-grade modulus k for the soil. The parameters , E, and k were later used together with the damage parameter in the finite element simulation of the strength of the damaged pile using Eigen value analyses. The layered soil modulus is approximated by taking the mean value and is denoted by . The discrete element matrices are assembled into a system Eigen-value equation, the solution of which provides the stability or instability loads for the damaged pile. The results obtained for a pile without damage, that is, when =0 , are in good agreement with those published in the literature. It has also been found that higher soil resistance is needed to support the damaged pile. It is concluded that the proposed model is a good candidate for use in the analysis and repair of damaged piles due to earthquake overload by soil stabilization methods.

폐금속 광산 주변 비소 및 중금속 오염농경지의 안정화 처리를 위한 석회석과 제강슬래그의 처리효과 검토

A soil stabilization method is an effective and practical remediation alternative for arsenic (As) and heavy metal contaminated farmland soils nearby abandoned metal mine in Korea. This method is a technique whereby amendments are incorporated and mixed with a contaminated soil. Toxic metal bind to the amendments, which reduce their mobility in soil, so the successful stabilization of multi-element contaminated soil depends on the combination of critical elements in the soil and the type of amendments. The objective of this study is to investigate the treatment effects and applicability of limestone (LS) and steel refining slag (SRS) as the amendment for farmland soil contaminated with As and heavy metals, and a lab-column test was conducted for achieving this purpose. The result showed that soil treated with LS and SRS maintained pH buffer capacity and, as a result, the heavy metal leaching concentration was quite low below the water quality standard compared to untreated soil which leachate exceeding the water quality standard was observed, however, the arsenic concentration rather increased with increasing mixture ratio of SRS. This was believed to be related to phosphorus (P) contained in SRS, and dominancy in the competitive adsorption relation between As and P binding strongly to iron might be different according to soil characteristic. We suggested that LS is a effective amendment for reducing heavy metals in soil, and SRS should be used after investigating its applicability based on the adsorption selectivity of arsenic and phosphorus in selected soil.

Revegetation of ski runs in Serbia: Case studies of Mts. Stara Planina and Divcibare

Revegetation is the most sustainable method of soil stabilization at ski runs. In order to establish a stable plant community, it is recommended to use native species. However, non-native species are most often used. In this paper the revegetation of ski runs at two ski resorts is investigated: Divcibare and Stara Planina. Seven species were used for the revegetation of the ski run at the Divcibare ski resort of which six species were native. Six species were used for the revegetation of the Stara Planina ski resort, of which two species were native. It was established that the plant species used in the seed mixtures were suitable for erosion control at the investigated ski resorts.

Microbial phytase-induced calcium-phosphate precipitation — a potential soil stabilization method

Two hypotheses were tested: (1) microbial dephosphorylation of phytate in the presence of Ca²+ ions will result in the precipitation of hydroxyapatite-like crystals and (2) precipitation of calcium-phosphate crystals on and between sand-like particles can cause cementation. A growing culture of the dimorphic phytase-active yeast Arxula adeninivorans was introduced into a column filled with quartz particles and subsequently a liquid growth medium amended with calcium phytate was pumped through the column resulting in increased strength and stiffness of the quartz particle matrix. Environmental scanning electron microscope analysis combined with energy-dispersive X-ray measurement revealed cementation of the quartz particles by calcium-phosphate crystals. This microbial mineralization process could provide a novel approach to improving the mechanical properties like strength and stiffness of sandy soils.

Influence of using rice husk ash in soil stabilization method with lime

In clayey lands, swelling problem causes vertical displacements on road subbase, and finally, failure in pavement occurs due to lack of appropriate drainage systems. One popular and inexpensive method of soil stabilization is using lime. Investigations indicate that based on environmental and atmospheric conditions, the chemical reaction of lime and clayey soil is not accomplished well, owning to low temperature and high humidity. This paper aims to investigate the influence of adding rice husk ash on the reaction between soil and lime and lime reaction and determine soil physical and mechanical characteristics. Therefore, sufficient laboratory soil tests, such as Atterberg limits, compaction, California bearing ratio (CBR), and direct shear test are carried out, and the results are analyzed. The results generally indicate that adding lime and rice husk ash (RHA) causes a decrease in dry density and an increase in optimum water content. Increasing lime and RHA causes a decreasing rate in soil liquid limit and plastic limit. Adding lime and RHA to the soil causes a decrease in deformability of soil samples and gives more brittle materials. Also, this action causes an increase in shear strength. Moreover, increasing in CBR amount under the influence of increasing RHA is one of the main results of this paper.

Stabilizing Potential Of Cement-Fly Ash Mixture On Expansive Clay Soil

This study investigated the stabilizing potential of cement-fly ash on expansive clay with a view to discovering a more effective soil stabilization method for road works. It was carried out between July 2003 and March 2004 in Civil Engineering Department, Obafemi Awolowo University, Ile-Ife, Nigeria.The expansive clay soil samples were first subjected to general classification tests where three classes of samples evolved; 12% cement optimal mix, 9% cement plus 3% fly ash optimal mix, and the 0% (unstabilized) natural clay soil sample. The three different classes of samples were then subjected to engineering tests; Maximum Dry Densities (MDD), Optimum Moisture Contents (OMC), California Bearing Ratio (CBR), Unconfined Compression and the Undrained Triaxial. The results showed that the soil sample stabilized with a mixture of 9% cement plus 3% fly ash was better in respect to MDD, OMC, Bearing Capacity and Shearing Resistance, when compared with sample stabilized with 12% cement plus 0% fly ash. This showed that the addition of a certain percentage of fly ash will improve the stabilizing potential of cement on an expansive clay soil. Keywords: Cement and fly ash stabilization; soil strength; expansive clay; amendment.Journal of Technology and Education in Nigeria Vol. 12 (2) 2007: pp. 1-8