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

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.

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.


Author(s):  
Kristýna Bláhová ◽  
Lenka Ševelová ◽  
Pavla Pilařová

Shear strength of soils is highly affected by moisture conditions (i.e. water content), especially if the soil contains clay materials. Usually the laboratory specimen, which are used to determine shear strength of soil are prepared at water content and dry density same as in the field conditions, without respect to the fact, that the conditions in the future might not remain the same. For the purpose of this study soil specimen were compacted and the optimum moisture content was identified. After compaction soil was tested at the dry side of optimum water content at w = 9 %, 10 % and 11 %. Parameters of shear strength were obtained and used for stability analysis with software GEOSLOPE/W 2012. According to referenced literature, it was expected for the shear strength of the soil to decrease with increasing water content. This hypothesis was not proven for clayey soil from Brno region. Development of values of friction angle and cohesion exhibited anomalous behaviour and such development was found also for values of Factor of safety (FOS) obtained from stability analyses. Results proved the necessity of taking moisture conditions into account, when processing stability analyses, in order to achieve reliable and safe constructions.


2020 ◽  
Vol 2 (1) ◽  
pp. 55-61
Author(s):  
Ahmed Eltwati ◽  
Alaa Elkaseh ◽  
Fares Tarhuni ◽  
Saleh Ahmeed Buagela

Soft soils such as clay soils, mostly if they comprise swelling minerals may produce great damage to structures, particularly when these soils are exposed to wetting and drying situations. The geotechnical properties of soft soils could be enhanced by utilizing chemical additives. In this paper, granite waste dust was used to adjust the properties of clay soils. This paper investigates the effect of granite rock dust on the geotechnical properties of soft soil. The particle size distribution, Atterberg limits, compaction, California bearing ratio (CBR) and direct shear strength characteristics of the soil when blended with various percentages of granite dust were evaluated. The findings show a great increase in the maximum dry density, optimum water content, direct shear strength and CBR with increasing the amount of granite dust. The best results obtained for CBR values were when the soils mixed with 8% granite dust. Although these findings indicate great improvement in the geotechnical parameters of clayey soils, the higher strength established is not enough for the enhanced soil to be utilized as a base material in the construction of heavily-trafficked flexible pavements. However, this modified material can be used as a base material for moderate traffic roads and as a sub-base material for high traffic roads.


Author(s):  
Muhannd Waleed Majeed ◽  
Lubna Mohammed Abd ◽  
Mohammed Nsaif Abbas

Soil moisture content is one of the most important ecological factors affecting natural ecosystems. This study deals with the soil moisture distribution and its effect on the different types of soil used such as sandy soil, clayey soil, expansive soil and gypsum soil. Each type is brought to the laboratory to determine the physical properties then prepared for compaction test to determine the maximum dry density and optimum water content and discussed the result by comparing the values with them. The largest value of maximum dry density was for clayey soil while the smallest value was for gypsum soil. The largest optimum moisture content was for expansive soil while the smallest value was for gypsum soil too.


2008 ◽  
Vol 45 (5) ◽  
pp. 715-725 ◽  
Author(s):  
Brendan C. O’Kelly

The geotechnical properties of a municipal water treatment sludge from an upland catchment are presented. The gelatinous sludge comprised flocs of mainly quartz, manganoan calcite, and clay-sized organic solids, and incorporated an alum coagulant and an anionic polyelectrolyte. Standard Proctor compaction yielded low bulk density values of 0.95–1.10 t/m3 and dry density values of 0.12–0.36 t/m3 (water content is 160%–780%) in line with the low specific gravity of solids value of 1.86. The undrained shear strength and the water content were inversely related on a semi-log plot. The effective stress shear strength parameter values were c' = 0 and ϕ' = 39°. The consolidation properties were studied using the oedometer, consolidometer, and triaxial apparatus. The material was highly compressible with primary compression index (Cc) values of 2.5–3.7, and primary compression ratio (C*c) values of 0.20–0.28. The majority of the strain response occurred due to primary consolidation although the material had a very low permeability (coefficient of permeability values decreasing from 2 × 10−9 to 5 × 10−11 m/s for an effective vertical stress of σ'v = 3–800 kPa). Secondary compression was minor, with a mean secondary compression index (Cαe) value of 0.15, and Cαe/Cc = 0.04–0.06.


Author(s):  
Harpreet Singh

Abstract: Soil is the most widely used and basic material for civil engineering. The soil is used for houses, walls, bridges and roads. The Earth provides various types of soil and varies in its properties, scale, composition and textures. The earth's soil is a natural fine grain rock that contains one or more minerals from Earth, which have metal oxides and traces of organic matter. Based on the structure, the clay has quite a range of characteristics. It's slow, and difficult to accelerate, and used for something small. This study is aimed at achieving soil engineering properties for subgrade. In the subgrade construction, waste plastic bottles are used from waste disposal and the application of raw waste soil reinforcement materials and tried to stabilize the clay soil in different strong lime percentages (2 percent, 4 percent, 6 percent, 8 percent, 10 percent, and 12 percent). Testing of the strength of the clay earth, like Maximum Dry Density (MDD) and California Bearing (CBR) was done at different plastic strip percentages. In order to measure improvements in technologies, the clay floor swelling index and the microscopic examination also are performed. Keywords: Clay soil, Lime, Plastic, fiber material.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Gang Huang ◽  
Mingxin Zheng

Strength of vegetated coal-bearing soil is of great significance to evaluate the shallow stability of vegetated slopes in coal-bearing soil regions. This paper takes D-W cycles, dry density, water content, and vegetation root (VR) content as four factors and carries out the triaxial test for the orthogonal design of vegetated coal-bearing soil in southern China. The strength curves of vegetated coal-bearing soil under four factors were obtained. The Taguchi method was used to quantitatively analyse the effects of four factors. The microstructure of coal-bearing soil under D-W cycles and the theory of soil reinforcement by VR were discussed. The results indicated that D-W cycles had a significant effect on the cohesion and internal friction angle ( P < 0.05 ). The internal friction angle was little affected by the water content and VR content, which had considerable influence on the cohesion. The cohesion could be improved with less than 2% VR content. The cohesion was the largest for no D-W cycles, 10% water content, and 2% VR content. The links between mineral particles go from a stable layered structure to unsteadiness chain structure with the increase in the number of D-W cycles.


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