scholarly journals Evaluation of Subsoil Compaction of Plastic Soils

2017 ◽  
Vol 21 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Kinga Śnieg ◽  
Dariusz Błażejczak

Abstract The objective of the research was to evaluate soil compaction with selected indexes and to determine the relation between them including results obtained with Proctor’s method. Measurements of penetration resistance and shear vane, dry density of soil particles (ρd) and their moisture were made in layers in the following depths: 25-30, 35-40, 45-50 and 55-60 cm. Moreover, the maximum volumetric density of soil particles, particles size distribution, content of calcium carbonate and humus, density of solid particles, reaction, plastic and liquid limit were determined with Proctor's method (ρds). Also, packing density and natural density were measured. It was found out that the investigated soils may be generally included to excessively compacted and susceptible to compaction to an average and small degree. It was shown that soil may be recognized as excessively compacted when the quotient ρd/ρds exceeds the value of 0.87.

Soil compaction involves concretion and a relative variation of physical and mechanical properties of soils. Determining laboratory compaction characteristics such as maximum dry density (MDD) and optimum moisture content (OMC) could be vital work to manage field compaction for all earth-works structures. There are 3 necessary Atterberg limits: plastic limit (PL), liquid limit (LL), and Plastic Index (PI). The most objective of this paper is to get the relationships between compaction parameters and their Atterberg limits of fine-grained soils and to create reliable correlations. For conducting this work, forty samples are collected from a borrowed space that is found at the bank upstream of Setit watercourse. The tests of soil samples were executed at the laboratory of Dam complex of the upper Atbara project. To perform this work, the Microsoft Office Excel software was exercised for the regression analysis of compaction parameters and Atterberg limits. Several trials were created to get the relationships between Atterberg limits (LL, PL, and PI) with the compaction parameters (OMC, and MDD). From the regression analysis, it's found that OMC and MDD have an excellent relationship with the LL other than the PL and PI. It had been observed that the (OMC) has an excellent correlation with (MDD) other than the remaining parameters. From this work, it's going to be suggested to use the soil compaction properties and Liquid Limits' correlations attributable to their reliable results compared with the other correlations. The result of the paper may be helpful and applicable in numerous civil engineering sectors, particularly for preliminary investigations and prefeasibility studies of various civil engineering works.


2016 ◽  
Vol 20 (3) ◽  
pp. 5-14 ◽  
Author(s):  
Dariusz Błażejczak ◽  
Jan B. Dawidowski

AbstractThe objective of the paper was to verify the previously obtained results of research concerning the impact of the plate diameter on the measured value of the pre-compaction stress of silt (NG), in conditions of a wider range of soil types and their initial stage. The research was carried out on samples with a diameter of 100 mm and height of 30 mm produced from the soil material (M) or collected from the subsoil of the selected soils (AWN) with the granulation type of: silt loam, loam, light loam, sandy-clay soil. The following soils properties were determined: the granulation type, density of the solid phase, content of humus and calcium carbonate, reaction, plastic and liquid limit. The properties of samples were described with moisture, dry density of solid particles, porosity of aeration, degree of plasticity and degree of saturation. The samples were loaded with a testing machine with plates with varied diameters. The value of the pre-compaction stress of soil was measured with the method of searching the crossing point of tangents with the secondary stress curve and the original stresses curve (a classical method). It was found out that for samples M with the degree of saturation of 0.40-0.50, the pre-compaction stress does not significantly depend on the plate diameter. For samples M or AWN, with the degree of saturation of 0.64-0.82, the pre-compaction stress significantly depends on the diameter of the plate. A conclusion was formulated that in the research of NG with the method of uniaxial defonnations, the relation of the diameter of the plate (d) to the diameter of the cylinder (D) should be within 0.5 ≤ d/D ≤ 0.8.


2017 ◽  
Vol 21 (1) ◽  
pp. 19-28
Author(s):  
Dariusz Błażejczak ◽  
Jan B. Dawidowski

Abstract The objective of the paper was to verify previously obtained results of research on the impact of the plate diameter on the determined value of pre-compaction stress of soil (NG) with a wider selection of dimensions of samples. Tests were carried out on samples with a diameter (D) of 100 mm and heights (H) of 30, 50 or 100 mm produced from the soil material (M) or collected (NNS) from subsoil with the granulation group of: silt loam, loam, sandy loam, sandy clay loam. The following soil properties were determined: granulation type, density of the solid phase, content of humus and calcium carbonate, reaction, plastic and liquid limit. Properties of samples were described with moisture, dry density of solid particles, porosity of aeration, degree of plasticity and saturation. Samples were loaded with plates of varied diameters. The NG value was calculated with the method of searching for the crossing point of tangents with the secondary stress curve and the virgin stresses curve (a traditional method). It was stated that the plate diameter (d) and sample height (H) do not influence the measurement results when the relation d/D is within 0.5 ≤ d/D ≤ 0.8 and the ratio D/H equals 2. It is possible to omit the condition d/D in a situation when soil is low cohesive and its degree of moisture is ca. 0.41-0.44.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ubido Oyem Emmanuel ◽  
Igwe Ogbonnaya ◽  
Ukah Bernadette Uche

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.


2018 ◽  
Vol 162 ◽  
pp. 01020 ◽  
Author(s):  
Nahla Salim ◽  
Kawther Al-Soudany ◽  
Nora Jajjawi

All structures built on soft soil may experience uncontrollable settlement and critical bearing capacity. This may not meet the design requirements for the geotechnical engineer. Soil stabilization is the change of these undesirable properties in order to meet the requirements. Traditional methods of stabilizing or through in-situ ground improvement such as compaction or replacement technique is usually costly. Now a safe and economic disposal of industrial wastes and development of economically feasible ground improvement techniques are the important challenges being faced by the engineering community. This work focuses on improving the soft soil brought from Baghdad by utilizing the local waste material for stabilization of soil, such as by using “Nylon carry bag’s by product” with the different percentage and corresponding to 1 %, 3% and 5% (the portion of stabilizer matters to soil net weight) of dried soil. The results indicated that as Nylon’s fiber content increases, the liquid limit decreases while the plastic limit increases, so the plasticity index decreases. Furthermore, the maximum dry density decreases while, the optimum moisture content increases as the Nylon’s fiber percentage increases. The compression index (decreases as the Nylon’s fiber increases and provides a maximum of 43% reduction by adding 5% nylon waste material. In addition, the results indicated that, the undrained shear strength increases as the nylon fiber increases.


2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Sara Mansouri ◽  
Mehran Nasiri ◽  
Amir Modarres

Many pozzolans are waste products from industrial processes. Every year a huge amount of coal waste is gathered from the coal washing plant in the Hyrcanian forests of Iran. These materials can be used for soil stabilization in construction and maintenance projects of forest roads. This paper aims to (a) investigate the role of coal waste (CW) as a soil stabilizer and (b) determine the changes in soil specification regarding the environmental pollution in different combinations of materials (soil, lime (4 and 6%) and CW (3, 6, 9 and 12%)). For this purpose, different technical and environmental analysis and laboratory tests were performed. Technical tests showed that the soil liquid limit and maximum dry density decreased with an increase in lime and CW contents. Addition of CW could increase the soil CBR, UCS and OMC. According to XRD test, the addition of CW and lime can increase the size of crystals in stabilized soil samples. Environmental analysis showed that the use of stabilizer significantly reduced the concentration of heavy metals such as Cd, Cr and Pb. Also, all of the metal concentrations leached from samples satisfied the required criteria, but the addition of lime and CW increased the concentration of N, P, and K. These changes can increase the invasive species consistent with calcareous soil conditions along the roads. According to the results, the combination of coal waste and lime can be one of the best methods for in situ remediation. It would, however, be better to use a minimum amount of stabilizer in pavement layers of access roads due to environmental sensitivity.


2021 ◽  
pp. 3417-3427
Author(s):  
Amera I. Hussain Hussain ◽  
Ibraheem I. Ibraheem

      In this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications.      The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges.  The results of the plasticity limits test showed that the soil is made of fine, low plasticity silt (ML), and low plasticity clay (CL), according to the unified standard soil classification. The water content and plasticity limit tests (liquid limit, plastic limit, and plasticity index) demonstrated that these clays are conformable with the limits of the Iraqi standards. The results of the modified compaction test found a maximum dry density value of 1.962 g/cm3 with an optimum moisture content of 11.5%. The results of the permeability index (K) revealed low permeability according to the Das classification and, therefore, showed the suitability of the samples as raw filling materials in the construction of dams. Chemical tests (sulfate content, organic materials content, total dissolved salts, gypsum content, and pH value) showed compatibility with the requirements for the use in dams construction under the Iraqi standard (SoRB/ R5).


2020 ◽  
Vol 857 ◽  
pp. 266-272
Author(s):  
Bushra S. Albusoda ◽  
Dhurgham A. Al-Hamdani ◽  
Mohammed F. Abbas

Dry density modeling is a valuable issue. Artificial neural networks (ANNs) have been used in many problems in geotechnical engineering and have demonstrated great success. In this paper, the ANN model is proposed to predict the dry density of the soil. The developed model is managed by the Matlab Neural Network Interface (R2016a). To create the ANN model, liquid limit, plastic limit, plasticity index, moisture content, specific gravity, finer accuracy than sieve 200, total suspended solids, organic and SO3 were selected and used as input parameters. There are (9, 6,5 and 3) nodes, (10) nodes and (1) node used for input, hidden layers and output layers, respectively. The value of dry density obtained from three sources was sympathetic. The first source is the experimental results of 99 soil samples conducted in Al-Najaf Institution laboratory for this study. The second source was to propose the expected dry density using multiple linear regression analysis (MLRA) on the samples used in the first source; The results show, that the prediction of the use of ANNs was closely consistent with the experimental data. Correlation coefficient (R2) and mean square error (MSE) were 0.97368 and 3.19474 10-3, respectively. The observed results of the proposed system were very comparable with those obtained from empirical analysis and the prediction obtained from multiple linear regression analysis, where the advanced ANN approach is applicable.


Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 292 ◽  
Author(s):  
Katja Augustin ◽  
Michael Kuhwald ◽  
Joachim Brunotte ◽  
Rainer Duttmann

Avoiding soil compaction is one of the objectives to ensure sustainable agriculture. Subsoil compaction in particular can be irreversible. Frequent passages by (increasingly heavy) agricultural machinery are one trigger for compaction. The aim of this work is to map and analyze the extent of traffic intensity over four years. The analysis is made for complete seasons and individual operations. The traffic intensity is distinguished into areas with more than five wheel passes, more than 5 Mg and 3 Mg wheel load. From 2014 to 2018, 63 work processes on a field were recorded and the wheel load and wheel passes were modeled spatially with FiTraM. Between 82% (winter wheat) and 100% (sugar beet) of the total infield area is trafficked during a season. The sugar beet season has the highest intensities. High intensities of more than five wheel passes and more than 5 Mg wheel load occur mainly during harvests in the headland. At wheel load ≥3 Mg, soil tillage also stresses the headland. In summary, no work process stays below one of the upper thresholds set. Based on the results, the importance of a soil-conserving management becomes obvious in order to secure the soil for agriculture in a sustainable way.


2018 ◽  
Vol 9 (1) ◽  
pp. 68 ◽  
Author(s):  
Samnang Phoak ◽  
Ya-Sheng Luo ◽  
Sheng-Nan Li ◽  
Qian Yin

In this study, the influence of fly ash (FA) content (0%, 10%, 20%, and 30%) on the alteration in the physical and mechanical parameters of loess is investigated. The influences of curing time (0, 14, and 28 days) and submergence and non-submergence conditions are analyzed as well. Analysis considers the variation in Atterberg limits (liquid limit, plastic limit, and plasticity index), compaction parameters (optimum moisture content (OMC), and maximum dry density (MDD)), unconfined compressive strength (UCS) stress, UCS strain, California bearing ratio (CBR) value, and swell potential. Results show that the application of FA-stabilized loess (FASL) is effective. Specifically, the MDD decreases and the OMC increases, the UCS stress increases and the UCS strain decreases, the CBR value improves and the swell potential declines, but Atterberg limits are insignificantly changed by the increase in the FA ratio compared with those of untreated loess. The UCS stress and CBR value are improved with the increase in curing time, whereas the UCS strain is negligible. FASL under submergence condition plays an important role in improving the effect of FA on the UCS stress and CBR value compared with that under non-submergence condition. The UCS stress and CBR value are more increased and more decreased than the UCS strain in submerged samples. Therefore, the application of FASL in flood areas is important for obtaining sustainable construction materials and ensuring environmental protection.


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