scholarly journals On Random Subspace Optimization-Based Hybrid Computing Models Predicting the California Bearing Ratio of Soils

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6516
Author(s):  
Duong Kien Trong ◽  
Binh Thai Pham ◽  
Fazal E. Jalal ◽  
Mudassir Iqbal ◽  
Panayiotis C. Roussis ◽  
...  
Keyword(s):  
Clayey Soil ◽  
Optimization Technique ◽  
California Bearing Ratio ◽  
Coefficient Of Determination ◽  
Dry Density ◽  
Random Subspace ◽  
Sand Content ◽  
Hybrid Computing ◽  
Subspace Optimization ◽  
Computing Models

The California Bearing Ratio (CBR) is an important index for evaluating the bearing capacity of pavement subgrade materials. In this research, random subspace optimization-based hybrid computing models were trained and developed for the prediction of the CBR of soil. Three models were developed, namely reduced error pruning trees (REPTs), random subsurface-based REPT (RSS-REPT), and RSS-based extra tree (RSS-ET). An experimental database was compiled from a total of 214 soil samples, which were classified according to AASHTO M 145, and included 26 samples of A-2-6 (clayey gravel and sand soil), 3 samples of A-4 (silty soil), 89 samples of A-6 (clayey soil), and 96 samples of A-7-6 (clayey soil). All CBR tests were performed in soaked conditions. The input parameters of the models included the particle size distribution, gravel content (G), coarse sand content (CS), fine sand content (FS), silt clay content (SC), organic content (O), liquid limit (LL), plastic limit (PL), plasticity index (PI), optimum moisture content (OMC), and maximum dry density (MDD). The accuracy of the developed models was assessed using numerous performance indexes, such as the coefficient of determination, relative error, MAE, and RMSE. The results show that the highest prediction accuracy was obtained using the RSS-based extra tree optimization technique.

scholarly journals Multivariate Assessment of California Bearing Ratio with Contrasted Geotechnical Properties of Soils in Ilorin-Lokoja Highway

2021 ◽  
Author(s):  
Attah Fakeye ◽  
Olusegun Ige ◽  
Olufemi Ogunsanwo
Keyword(s):  
Road Construction ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Coarse Sand ◽  
Plasticity Index ◽  
California Bearing Ratio ◽  
Coefficient Of Determination ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Free Swell

California Bearing Ratio (CBR) is an important parameter used in designing pavement layers in road construction but testing this parameter requires time, labor, and huge cost. The study therefore applies multivariate approach to evaluate CBR based on contrasted geotechnical parameters along Ilorin-Lokoja highway. The results obtained showed that the migmatite-gneiss-derived soils are slightly more fines (< 0.075 mm; 7.4–59.6%), more plastic (PI; 1.6–39%), and have low strength (MDD = 1.8 mg/m3; CBR = 29.0%) than the metasediments (11–57.7%, 2.0–30%, 1.6 mg/m3, 23.6%) and older granite soils (8.2–32.7%, 2.6–13.4%, 1.7 mg/m3, 27.8%), respectively. The principal component analysis (PCA) revealed three major components (eigenvalues >1) which accounted for 83.8% of the total variance at the rate of 33.4, 14.7, and 11.4%. Major contributing variables for the components were fines (R = 0.87), plasticity index (R = 0.7), and coarse sand (R = 0.67%). Spatial distribution of these groups established interplay of sediment-gradation and moisture-connection evident in hierarchical cluster analysis that revealed patterns of homogeneity and soil relationships. Regression analysis established five models from predictor variables such as fines, activity, free swell, liquid and plastic limits, weighted plasticity index, optimum moisture content, and maximum dry density with the coefficient of determination (R2 = 0.33) and root mean square error (RMSE) of 7.80.

scholarly journals Strength Characteristics of Crushed Concrete and Carbide Wastes Stabilization of Clayey Soil as Highway Material

2020 ◽  
Vol 1 (3) ◽  
pp. 1-7
Author(s):  
Joseph Ejelikwu Edeh
Keyword(s):  
Moisture Content ◽  
Clayey Soil ◽  
Resilient Modulus ◽  
Construction Material ◽  
California Bearing Ratio ◽  
Engineering Properties ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Crushed Concrete ◽  
Pavement Structures

The functionality of a highway pavement is often judged by the quality and engineering properties of the soil-pavement structures and the materials used to improve the properties of these underlying soils. In this study, crushed concrete waste and carbide waste, whose associated disposal problems constitute environmental hazard, were used for the stabilization of clayey soil using British Standard heavy (Modified Proctor) compaction energy, and used as highway construction material. The various mixes were subjected to particles size analyses, specific gravity, moisture content, Atterberg limits, compaction characteristics, California bearing ratio, unconfined compressive strength test triaxial and water absorption tests. The test results show that the properties of the clayey soil improved with its stabilization with crushed concrete and carbide wastes. The maximum dry density decreased from 1.93 to 1.29 Mg/m3 with corresponding increase in optimum moisture content from 6.0 to 16.6 %, as carbide waste content increased, and crushed concrete waste and clayey soil contents of the mixtures decreased. The maximum California bearing ratio value of 55.01 % (unsoaked and soaked for 24 h) recorded for 25%CS + 75% (75%CCW + 25%CW) mix can be used as subbase material in flexible pavement construction. Further work may assess resilient modulus of this material under cyclic load.

scholarly journals Geomechanical Behaviour of Uncemented Expanded Polystyrene (EPS) Beads–Clayey Soil Mixtures as Lightweight Fill

Geotechnics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 38-58
Author(s):  
Pouyan Abbasimaedeh ◽  
Ali Ghanbari ◽  
Brendan C. O’Kelly ◽  
Mohsen Tavanafar ◽  
Kourosh Ghaffari Irdmoosa
Keyword(s):  
Clayey Soil ◽  
Expanded Polystyrene ◽  
Environmental Cost ◽  
Dry Density ◽  
Engineering Practice ◽  
Clayey Sand ◽  
Earth Pressures ◽  
Lightweight Fill ◽  
Soil Foundation ◽  
Geotechnical Testing

Lightweight fill can be advantageous in embankment construction for the purposes of reducing the (i) bearing pressures on the underlying soil foundation, (ii) destabilizing moments for constructed earthen slopes, and (iii) earth pressures acting behind retaining walls. This paper investigates the merits/limitations of particulate expanded polystyrene (EPS) beads mixed with clayey sand (CS) soil as lightweight fill, considering both geotechnical and environmental perspectives. The bench-scale geotechnical testing programme included standard Proctor (SP) compaction, California bearing ratio (CBR), direct shear (sheardox), oedometer and permeability testing performed on two different gradation CS soils amended with 0.5, 1.5 and 3.0 wt.% EPS, investigating two nominal bead sizes equivalent to poorly-graded medium and coarse sands. Compared to the unamended soils, the compacted dry density substantially decreased with increasing EPS beads content, from 2.09 t/m3 (0 wt.% EPS) to as low as 0.33 t/m3 for 3 wt.% (73 v.%) of larger-sized EPS beads. However, from analyses of the test results for the investigated 50 to 400 kPa applied stress range, even 0.5 wt.% (21 v.%) EPS beads caused a substantial mechanical failure, with a drastic decay of the CBR and compressibility parameters for the studied CS soils. Given the more detrimental environmental cost of leaving myriads of separate EPS beads mixed forever among the soil, it is concluded that the approach of adding particulate EPS beads to soils for producing uncemented lightened fill should not be employed in geotechnical engineering practice.

scholarly journals Characterization and Comparison Research on Composite of Alluvial Clayey Soil Modified with Fine Aggregates of Construction Waste and Fly Ash

2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
Qu Jili ◽  
Wang Junfeng ◽  
Batugin Andrian ◽  
Zhu Hao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Construction Waste ◽  
Comparison Research ◽  
Fine Aggregates ◽  
Optimum Water Content

Abstract Fine aggregates of construction waste and fly ash were selected as additives to modify the characteristics of Shanghai clayey soil as a composite. The laboratory tests on consistency index, maximum dry density, and unconfined compressive strength were carried out mainly for the purpose of comparing the modifying effect on the composite from fine aggregates of construction waste with that from fly ash. It is mainly concluded from test results that the liquid and plastic limit of the composites increase with the content of two additives. But their maximum dry density all decreases with the additive content. However, fine aggregates of construction waste can increase the optimum water content of the composites, while fly ash on the contrary. Finally, although the two additive all can increase the unconfined compressive strength of composites, fly ash has better effect. The current conclusions are also compared with previous studies, which indicates that the current research results are not completely the same as those from other researchers.

scholarly journals Geotechnical properties of reinforced clayey soil using nylons carry’s bags by products

2018 ◽  
Vol 162 ◽  
pp. 01020 ◽  
Author(s):  
Nahla Salim ◽  
Kawther Al-Soudany ◽  
Nora Jajjawi
Keyword(s):  
Soil Stabilization ◽  
Clayey Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Liquid Limit ◽  
Waste Material ◽  
Industrial Wastes ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Replacement Technique

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.

scholarly journals Effect of Sand Percentage on the Compaction Properties and Undrained Shear Strength of Low Plasticity Clay

2021 ◽  
Vol 9 (1) ◽  
pp. 16-20
Author(s):  
Iyad Alkroosh ◽  
Ali Al-Robay ◽  
Prabir Sarker ◽  
Saif Alzabeebee
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Undrained Shear Strength ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Sand Content ◽  
Compression Tests ◽  
Maximum Dry Density ◽  
Sand Mixture ◽  
Undrained Shear

This paper investigates the influence of sand content on the mechanical behavior of a low plasticity clay that collected from south of Iraq (Sumer town). Samples have been prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the clay weight. Standard Proctor and unconfined compression tests have been carried out and the optimum moisture content, maximum dry density, and undrained shear strength have been determined. The results show a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reaches 1.90 g/cm3 corresponding to an optimum moisture content of 12%. In addition, this paper shows that the undrained shear strength is inversely proportional to the increase of the percentage of sand. The results of this work provide a useful addition to the literature regarding the behaviour or low plasticity clay-sand mixture.

Geotechnical Characterization of Water Treatment Sludge for Liner Material Production and Soft Soil Reinforcement

2021 ◽  
Vol 1046 ◽  
pp. 83-88
Author(s):  
Leonardo Marchiori ◽  
André Studart ◽  
António Albuquerque ◽  
Victor Cavaleiro ◽  
Abílio P. Silva
Keyword(s):  
Water Treatment ◽  
Water Content ◽  
Clayey Soil ◽  
Soft Soil ◽  
Soil Reinforcement ◽  
Dry Density ◽  
Water Treatment Sludge ◽  
Soft Soils ◽  
Liner Material ◽  
Material Production

A water treatment sludge (WTS) was characterized in order to evaluate if its properties would be suitable for use as liner of earthworks or for strengthening a clay soil. A WTS and a clayey soil was characterized in terms of granulometry, cumulative volumes, specific surface, density, plastic limit, liquid limit, water content, hydraulic conductivity, and characteristics of compaction (optimal water content and dry density). This study aimed to exhibit and evaluate these investigated parameters of WTS, soft soil and mixed proportions between the materials for liners’ material production while evaluating soft soils’ reinforcement feasibility. The results have shown WTS’s contribution with its fine granulometry and compaction characteristics, indicating filling properties and possible feasibility as soft soils additions for liners’ material production while being applicable for soils‘ reinforcements, corroborating with existing literature on the subject. Thus, the currently developed investigation has exposed WTS as a potential addition for these applications while also attending society’s new demands towards a more sustainable future.

scholarly journals Investigation and Optimization of the C-ANN Structure in Predicting the Compressive Strength of Foamed Concrete

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1072 ◽  
Author(s):  
Dong Van Dao ◽  
Hai-Bang Ly ◽  
Huong-Lan Thi Vu ◽  
Tien-Thinh Le ◽  
Binh Thai Pham
Keyword(s):  
Compressive Strength ◽  
Civil Engineering ◽  
Mean Squared Error ◽  
Model Performance ◽  
Absolute Error ◽  
Machine Learning Algorithms ◽  
Coefficient Of Determination ◽  
Dry Density ◽  
Statistical Measures ◽  
Foamed Concrete

Development of Foamed Concrete (FC) and incessant increases in fabrication technology have paved the way for many promising civil engineering applications. Nevertheless, the design of FC requires a large number of experiments to determine the appropriate Compressive Strength (CS). Employment of machine learning algorithms to take advantage of the existing experiments database has been attempted, but model performance can still be improved. In this study, the performance of an Artificial Neural Network (ANN) was fully analyzed to predict the 28 days CS of FC. Monte Carlo simulations (MCS) were used to statistically analyze the convergence of the modeled results under the effect of random sampling strategies and the network structures selected. Various statistical measures such as Coefficient of Determination (R2), Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE) were used for validation of model performance. The results show that ANN is a highly efficient predictor of the CS of FC, achieving a maximum R2 value of 0.976 on the training part and an R2 of 0.972 on the testing part, using the optimized C-ANN-[3–4–5–1] structure, which compares with previous published studies. In addition, a sensitivity analysis using Partial Dependence Plots (PDP) over 1000 MCS was also performed to interpret the relationship between the input parameters and 28 days CS of FC. Dry density was found as the variable with the highest impact to predict the CS of FC. The results presented could facilitate and enhance the use of C-ANN in other civil engineering-related problems.

scholarly journals Laboratory characterization of reclaimed asphalt pavement for road construction in Egypt

2017 ◽  
Vol 44 (6) ◽  
pp. 417-425 ◽  
Author(s):  
E. Mousa ◽  
A. Azam ◽  
M. El-Shabrawy ◽  
S.M. El-Badawy
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Road Construction ◽  
California Bearing Ratio ◽  
Base Layer ◽  
Coefficient Of Determination ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Load Duration ◽  
The Impact

This paper presents the engineering characteristics of reclaimed asphalt pavement (RAP), blended with virgin aggregate for unbound base and subbase layers. The proportions of RAP were 0%, 20%, 60%, 80%, and 100% by total mass of the blend. The experimental laboratory testing included index properties such as gradation, modified Proctor compaction, California Bearing Ratio, and hydraulic conductivity. Repeated load resilient modulus testing was conducted on the blends. The impact of load duration on resilient modulus was also investigated. A strong inverse trend was found between resilient modulus and California Bearing Ratio. An accurate model was proposed for the prediction of the resilient modulus as a function of stress state and reclaimed asphalt pavement percentage with coefficient of determination of 0.94. Finally, multilayer elastic analysis of typical pavement sections with the base layer constructed of virgin aggregate and reclaimed asphalt pavement blends showed good performance.

Comparative Testing between Electrical Impedance and Hybrid Nuclear Devices for Measuring Moisture and Density in Soils

2017 ◽  
Vol 2657 (1) ◽  
pp. 29-36
Author(s):  
Ernest S. Berney ◽  
Mariely Mejías-Santiago
Keyword(s):  
Moisture Content ◽  
Research And Development ◽  
Electrical Impedance ◽  
Coefficient Of Determination ◽  
Dry Density ◽  
Engineer Research ◽  
Construction Operations ◽  
Scale Test ◽  
Development Center ◽  
Crushed Limestone

The U.S. Army Engineer Research and Development Center validated the effectiveness of the TransTech Combined Asphalt Soil Evaluator (CASE) electrical impedance gauge and the Troxler eGauge hybrid electric-nuclear gauge as suitable replacements for nuclear density gauge (NDG) technology. Comparisons of soil density and moisture content were made between the gauges for six distinct soil types at varying densities and levels of moisture content. The CASE unit was calibrated using the sand cone and hot-plate moisture content prior to its correlation to the NDG; the eGauge was used in its shipped configuration without calibration. Full-scale test sections ranging from crushed limestone to fat clays were constructed for the soil evaluations. Results indicated that wet and dry densities obtained with the eGauge very closely matched those of the NDG, with a coefficient of determination (R2) of approximately 94%, but with an R2 of 85% for the measured moisture contents. The calibrated CASE unit's comparison with the NDG moisture content was excellent, with an R 2 of 98%, but the R 2 values were much lower than those of the eGauge for its dry and wet density, at 83% and 59%, respectively. Further, an average R2 of only 30% was found for the CASE unit's ability to capture changing wet density during construction operations, versus 80% for the eGauge. On the basis of the Engineer Research and Development Center findings, the eGauge is recommended as the better replacement for the NDG for wet or dry density measurements. It also requires little to no calibration and has no transport or licensing restrictions.

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