scholarly journals Experimental Investigation of Consolidation Properties of Nano-Bentonite Mixed Clayey Soil

2020 ◽  
Vol 12 (2) ◽  
pp. 459 ◽  
Author(s):  
Gang Cheng ◽  
Hong-Hu Zhu ◽  
Ya-Nan Wen ◽  
Bin Shi ◽  
Lei Gao
Keyword(s):  
Clayey Soil ◽  
High Stress ◽  
Soil Improvement ◽  
Soil Samples ◽  
Engineering Properties ◽  
Soil Consolidation ◽  
Water Drainage ◽  
Coefficient Of Consolidation ◽  
Test Soil ◽  
Permeability Increase

As a new soil improvement method, adding nano-bentonite can enhance the engineering properties of soil. To study the stabilization effect of nano-bentonite on soil consolidation properties, a series of one-dimensional odometer tests were conducted on a clayey soil with different nano-bentonite mixing contents (i.e., 0.5%, 1%, 1.5%, and 2%). The effects of nano-bentonite on the coefficient of consolidation and permeability of the test soil were analyzed. The results show that adding a certain amount of nano-bentonite does not significantly affect the original consolidation characteristics of soil samples, but displays a notable effect on accelerating water drainage. Among all the soil samples, when the nano-bentonite mixing content is 0.5%, the final compression amount is the largest and the final void ratio is the smallest. The coefficients of consolidation and permeability increase with increasing nano-bentonite mixing content under high stress state. The test results indicate that nano-bentonite can facilitate internal cementation of soil particles, which effectively reduces the compressibility of clayey soil.

scholarly journals GEOTECHNICAL INVESTIGATION OF PAVEMENT FAILURE; CAUSES AND INHERENT SOLUTIONS FOR SUSTAINABLE HIGHWAY CONSTRUCTION IN SUB-SAHARAN AFRICA

2020 ◽  
Vol 35 (4) ◽  
pp. 103-114
Author(s):  
Omowumi Ademila ◽  
Abel Idowu Olayinka
Keyword(s):  
Clayey Soil ◽  
Triaxial Compression ◽  
Road Construction ◽  
Liquid Limit ◽  
Soil Samples ◽  
Sub Saharan Africa ◽  
High Plasticity ◽  
Coefficient Of Consolidation ◽  
Geological Investigation ◽  
Undisturbed Soil

Engineering geological investigation of some unstable and stable sections of the Ibadan-Iwo-Osogbo highway was undertaken to unravel the intrinsic reasons responsible for continuous pavement failure along this road. Eighty disturbed and forty undisturbed soil samples were collected at different depths from twenty test pits of six selected failed sections (FS) and two stable sections (SS). Road construction analysis was done on these soil samples using standard methods. Liquid limit (22 - 64% and 32 - 40%), plasticity index (13 - 41% and 12 - 18%) and percentage fines (47 - 59% and 32 - 41%) indicated fair to poor and fair to good subgrade materials of FS and SS respectively. Medium to high plasticity and high clay content of soils of FS are indicative that the soils possess medium to high swelling potential. The activity of clay in soils of FS was approximately 0.3 – 1.2 and classified as inactive to normal clay. High linear shrinkage (> 10%), low compacted density and predominance of fines in soils of FS caused the instability. Exposure to excessive moisture led to strength reduction of the soils. Triaxial compression showed cohesion (72.6 - 127.0 kN/m2) and internal friction (12.7° - 33.3°) indicating moderate to good shearing strength of the soils. A coefficient of compressibility of 0.1 – 0.5 kN/m2 indicated incompetency of the soils for road construction and the coefficient of consolidation was 0.01 – 0.30 m2 /year. The subsoil of the FS is impervious with a relatively low coefficient of permeability, indicative high saturation in the region. Thus, the pavement failure was caused by water absorbing clayey soil, poor geotechnical parameters of the soils and a poor drainage network.

scholarly journals Coefficient of Consolidation and Volume Change for 3-D Consolidation

2019 ◽  
Vol 4 (5) ◽  
pp. 126-131
Author(s):  
Elsayed Abdelfatah El-Kasaby ◽  
Elnos Ali Eissa ◽  
Mohamed Farouk Ab-Elmeged ◽  
Ahmed Adel Abo-Shark
Keyword(s):  
Volume Change ◽  
Empirical Equation ◽  
Three Dimensional ◽  
Soil Samples ◽  
Two Dimensional ◽  
Soil Consolidation ◽  
Coefficient Of Consolidation ◽  
Fine Soil ◽  
Consolidation Coefficient ◽  
The Relationship

The settlement is the most serious problem of fine soil. This settlement is caused by a phenomenon called soil consolidation. Most previous studies were concerned with studying one (1-D) and two-dimensional (2-D) consolidation. That in some cases does not give a simulation of reality representation. It was necessary to study the three-dimensional (3-D) consolidation to simulate what happens to the fine soil in nature. Therefore, the consolidation behavior of four fine soils was studied in this paper. The studied soil samples were collected at the foundation levels of four different sites in El-Qalubia governorate, Egypt. A series of laboratory consolidation tests were carried out as one, two and three dimensional consolidation by using manufactured Oedometer apparatus. So, the effect of consolidation conditions (1-D, 2-D and 3-D) on consolidation coefficient (Cv) and volume change coefficient (mv) was investigated. Also, an empirical equation was correlated the relationship between Cv and mv.

scholarly journals Some Geotechnical Behaviour of Silty Clay Improved with Lime and Nanolime

2019 ◽  
Vol 92 ◽  
pp. 11005 ◽  
Author(s):  
Mohd Raihan Taha ◽  
Panbarasi Govindasamy ◽  
Jamal Alsharef
Keyword(s):  
Clayey Soil ◽  
Dry Weight ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Silty Clay ◽  
Minute Amount ◽  
Dissolved Silica ◽  
Clay Particles ◽  
Soil Plasticity ◽  
Noticeable Reduction

Chemical stabilization involves application of chemical admixtures to improve the behaviour of soil. Thus, this study was carried out to validate the effectiveness of nanolime additives as soil stabilizer. Lime and nanolime were chosen as additive to investigate its effect on some geotechnical properties of clayey soil. The soil was mixed with the additives ranging from 0.2 to 1.0% by dry weight of soil. The results indicate that adding a low percentage of nanolime can lead to a noticeable reduction in soil plasticity. It is found that a considerable improvement in soil compaction results was achieved with nanolime compared with lime. Nanolime shows superiority in soil improvement compared with lime even at the dosage of 0.5%. Chemical reactions between the calcium oxides and dissolved silica present in the soil mineral produced calcium silicate hydrate (CSH), where the morphology of this product can be recognized under FESEM test. The results indicate that the stabilization mechanism of treated soil involved flocculation and agglomeration of soil particles by Ca+2 which bridges the negatively charged clay particles The existence of even a minute amount of nanolime can result in extraordinary effects on the engineering properties of soil.

IMPROVEMENT OF EXPANSIVE SOIL BY ELECTRO-KINETIC METHOD

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Tran Thi Thanh Thuy ◽  
Doni Prakasa Eka Putra ◽  
Wawan Budianta ◽  
Hemanta Hazarika
Keyword(s):  
Shear Strength ◽  
Calcium Chloride ◽  
Pure Water ◽  
Expansive Soil ◽  
Soil Improvement ◽  
Undrained Shear Strength ◽  
Soil Samples ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Undrained Shear

The roadway in Karangjati, Ngawi Regency, East Java, Indonesia, which is underlain by expansive soil, is susceptible to damage due to volume change. This research aims to improve the engineering properties, such as consistency limits, compressibility, and undrained shear strength of the montmorillonite dominated soil in this area using an electrokinetic stabilization method. Four electro-kinetic experiments were conducted using different electrolytes (calcium chloride or pure water) under different conditions (no-flow or flow water). The results show that, pH values of all soil samples decreased at anolyte and increased at catholyte. Atterberg limits of the soil samples were found to increase, where the liquid limit (LL) range of 79.72– 86.14%, plastic limit (PL) 25.22–30.80%, and plasticity index (PI) 53.28–60.92, liquidity Index (LI) 0.91–1.08. The compression index Cc was 0.50– 0.742. Undrained shear strength of treated soil range of 7–11 kPa. Moreover, strengthening degree of the treated soils achieve 304–556%. The soil improvement was achieved by decreasing the Atterberg limits, and compressibility and increasing the undrained shear strength. Applying calcium chloride and flow water condition were the most effective methods for the soil improvement. The mineralogical compositions of the soil samples did not change after the treatment. Keywords: Electro-kinetic stabilization, electro chemical injection, clayey soil improvement.

Improvement in the Engineering Properties of Clayey Soil Using Sodium Chloride

2020 ◽  
Author(s):  
Harpinder Pal Singh ◽  
Jaspreet Singh Chana ◽  
Gurpreet Singh ◽  
Hardev Singh ◽  
Manvir Singh
Keyword(s):  
Sodium Chloride ◽  
Clayey Soil ◽  
Engineering Properties

scholarly journals Finite Element Study on Calculation of Nonlinear Soil Consolidation Using Compression and Recompression Indexes

2020 ◽  
Vol 10 (14) ◽  
pp. 4737
Author(s):  
Chao Xu ◽  
Suli Pan
Keyword(s):  
Finite Element ◽  
Case History ◽  
Time Dependent ◽  
Discrete Equation ◽  
Soil Consolidation ◽  
Coefficient Of Consolidation ◽  
Finite Element Study ◽  
Nonlinear Consolidation ◽  
Element Study

The coefficient of consolidation is traditionally considered as a constant value in soil consolidation calculations. This paper uses compression and recompression indexes to calculate the solution-dependent nonlinear compressibility, thus overconsolidation and normal consolidation are separated during the calculations. Moreover, the complex nonlinear consolidation can be described using the nonlinear compressibility and a nonlinear permeability. Then, the finite element discrete equation with consideration of the time-dependent load is derived, and a corresponding program is developed. Subsequently, a case history is conducted for verifying the proposed method and the program. The results show that the method is sufficiently accurate, indicating the necessity of considering nonlinearity for consolidation calculations. Finally, three cases are compared to reveal the importance of separating the overconsolidation and normal consolidation. Overall, this study concluded that it is inadequate to consider just one consolidation status in calculations, and that the proposed method is more reasonable for guiding construction.

Experimental Research on the Engineering Properties of Foam-Improved Red Clay Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1831-1835
Author(s):  
Guo Gang Qiao ◽  
Da Jun Yuan ◽  
Bo Liu
Keyword(s):  
Experimental Research ◽  
Clay Soil ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Screw Conveyor ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shield Tunneling ◽  
Red Clay ◽  
Improvement Measures

Red clay soil is widely distributed in south China, the microstructure of red clay soil was studied applying scanning electron microscopy (SEM), and the X-ray diffraction analysis (XRD) test found that a large number of swelling inducing minerals, for example, montmorillonite, illite-montmorillonite or chlorite-smectite were contained in the red clay soil. Shield tunneling in this kind of stratum is prone to arising “cake” and “arch” phenomena and it prone to lead screw conveyor device unsmooth dumping, so soil improvement measures must be taken. Foam as the most advanced soil conditioner has been widely used in shield construction. Using self-developed foam agent, experimental research on foam conditioning red clay soil was carried out, test results show that foam can not only significantly reduce the soil shear strength, but also can greatly enhance the soil's compressibility and fluidity, which is significant for the smooth dumping and excavation face stability maintenance.

scholarly journals Biochemical Enhancement of Geotechnical Properties of Marginal Soils

2018 ◽  
Vol 203 ◽  
pp. 03010
Author(s):  
Murtala Hassan Mohammed ◽  
Ado Yusuf Abdulfatah
Keyword(s):  
Hydraulic Conductivity ◽  
Treatment Duration ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Treatment Technique ◽  
Reagent Concentration ◽  
Soil Variables ◽  
Treatment Conditions ◽  
Metabolic Activities ◽  
Marginal Soil

Microbially-induced calcite precipitation (MICP) is a relatively new and sustainable soil improvement technique. This technique utilizes bio-activity of microorganism to precipitate calcite through metabolic activities of the organisms which decompose urea in to ammonium and carbon dioxide. The carbonate so produced combined with the supplied calcium to precipitate calcite. This calcite improves engineering properties of soil through the formation of coating and bonds between soil particles. Preliminary results have proved the feasibility of the isolated bacteria in MICP treatment technique to improve the engineering properties of marginal soil. The main objective of this study is to determine the preference conditions for effective MICP treatment in improving the soil engineering properties (Unconfined Compressive Strength, California Bearing Ratio and Hydraulic Conductivity) of a typical marginal soil. Variables such as; treatment duration (24, 48, and 72hours), reagent concentration (0.1, 0.25, 0.5, and 0.75M), and concentration of the isolates (1×105, 1×106, and 1×107cfu/ml) were considered in the MICP treatment. The results suggested that the preference treatment conditions were 72hours treatment duration, 0.75M reagent concentration, and 1×107cfu/ml concentration of the isolates. The corresponding alterations recorded were 94.86KN/m2 (295%) and 30.8% (92.5%) increment for CBR and UCS while 0.93X10-6m/s (78.95%) reduction was recorded for hydraulic conductivity. The calcite content showed a reasonably good comparison with the improvements in the soil engineering properties. The pH of effluents increased during MICP treatment indicating the presence of urease bio-activity.

scholarly journals Perbandingan Pengujian Konsolidasi Menggunakan Alat Rowe Cell dan Oedometer pada Tanah Lanau Lunak

2020 ◽  
Vol 22 (2) ◽  
pp. 149-155
Author(s):  
Iskandar ◽  
Rabiya
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soil Samples ◽  
Soil Parameters ◽  
Soil Consolidation ◽  
Test Results ◽  
Soft Soils ◽  
Better Than ◽  
Rowe Cell

Soil consolidation testing using an oedometer and rowe cell. Oedometers are often used on clay and soft soils. However, in the development of the rowe cell device, the results of lowering soft soil were better than the oedometer. The advantage of this rowe cell is that it can determine the saturation value of the soil samples tested. The rowe cell tester can measure the pore water pressure at the beginning and end of each consolidation stage. This rowe cell can provide suitable settlement for soft soils. This consolidation test to obtain soil parameters such as Cv and Cc by using the rowe cell tool. After that, from the test results, the two tools were compared.

scholarly journals The Improvement of Engineering Properties of Expansive Soil using Waste Glass Powder (WGP) and Quick Lime

2021 ◽  
Vol 9 (VI) ◽  
pp. 3598-3604
Author(s):  
Bhagwan Singh Lodha
Keyword(s):  
Glass Powder ◽  
Clayey Soil ◽  
Expansive Soil ◽  
Waste Glass ◽  
Engineering Properties ◽  
Binding Property ◽  
Unconfined Compression Test ◽  
Quick Lime ◽  
Waste Glass Powder ◽  
Consolidation Settlement

This study was carried out with an intention to observe any sign of improvement of expansive clayey soil due to the addition of Waste Glass Powder (WGP) with it. In this laboratory work clayey (BC) type soil has been chosen. The reason behind choosing clay is that it has many problems. The main problem is that it undergoes consolidation settlement due to the application of long-term loading. Another problem is it shrinks significantly if it is dried and expands significantly, if it absorbs moisture than exerts much pressure on the substructure. Quick Lime and Waste Glass powder is chosen to check the improvement because waste glass powder is cohesionless material and also contains silica, lime etc. Addition of cohesionless material to the cohesive soil means it will lesser the consolidation settlement and expansive nature of soil and Lime provides binding property. To investigate the traditional methods of analysing, the effect of additives on soil has been adopted i.e., conducting several tests of untreated soil and soil treated with waste glass and lime with varying percentage and then comparing the results obtained. The tests that were carried out in this study are Compaction test (Proctor test), Consolidation test (unconfined compression test). MDD and Unconfined compressive strength increases with the addition of glass powder and lime with oven dried expansive soil.

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