scholarly journals Engineering Characteristics and Reinforcement Approaches of Organic Sandy Soil

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Jun Hu ◽  
Liang Jia ◽  
Wei Wang ◽  
Hong Wei ◽  
Juan Du

Organic sandy soil is widely distributed throughout Hainan Island. This study aimed at addressing the distribution, composition, and formation of organic sandy soil. The engineering properties of organic sandy soil were examined. The experimental results showed that the coefficient of uniformity and coefficient of curvature were 2.07 and 1.25, respectively. The maximum dry density and optimum water content were 1.723 g/cm3 and 12.23%, respectively. The undrained shear strength of organic sandy soil was around 37.5 kPa. The effective stress parameters c and φ were around 4 kPa and 23°, respectively. The compound tangent-exponential model was adopted for capturing the stress-strain behavior of organic sandy soil. As the unconfined compressive strength of the cement-admixed organic sandy soil was much lower than that of ordinary sand, some innovative ground improvement technologies were proposed for stabilizing organic sandy soil, such as thermal pile, fiber, and steel-, bamboo-, and freezing-cemented soil columns. The main purpose of these technologies is to enhance the bearing capacity of organic sandy soil but reduce the usage of cement, as the latter is not an eco-friendly material.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Chuanyang Liang ◽  
Yuedong Wu ◽  
Jian Liu ◽  
Huiguo Wu ◽  
Dashuo Chen ◽  
...  

The particle size of expanded polystyrene (EPS) has an effect on engineering properties of EPS-clay blends. However, the effect of differences between EPS particle size groups subdivided within 1–3 mm on engineering properties is usually ignored. In this study, different particle sizes of EPS pellets have been considered to separately investigate the effect on the optimum water content (OWC), maximum dry density (MDD), unconfined compressive strength (UCS), ductility, coefficient of permeability, and compression index of EPS-clay blends. Results show that the MDD, ductility, hydraulic conductivity, and compression index of EPS-clay blends do not increase with the increase in the EPS particle size in the range of 0.3–3 mm, while the OWC and UCS do not decrease. For a given EPS content, among samples with the EPS particle size of 0.3–1 mm, 1-2 mm, and 2-3 mm, the MDD and UCS of EPS-clay blends with 1-2 mm in EPS particle size are the largest, while the OWC, ductility, coefficient of permeability, and compression index are the smallest. Microstructure analyses reveal that, for samples with the EPS particle size of 1-2 mm, the pore volume is lower and the microstructure is denser, which are the main reasons why the EPS particle size can influence engineering properties of EPS-clay blends.


2011 ◽  
Vol 243-249 ◽  
pp. 2586-2590 ◽  
Author(s):  
Xin Ping Li ◽  
Ya Ni Lu ◽  
Xing Hong Wu

In view of the fact that large amounts of tonhaltig phyllite were found along the Shi-Tian expressway line, these soft rocks could not meet the roadbed filling requirements. It was necessary to improve the weathered soft rocks to satisfy the engineering demands. Interior comparative tests research on seven modified methods were carried out such as part in different proportions of cement、sand or stone bits, with soft rock of different water contents being artificial to mix and stir evenly, then unconfined compression strength of the samples at different cement quantity、different curing ages were compared; the optimum water content and and maximum dry density were determined through the compaction test; In addition, the principal effect of CBR value was analyzed. thus the best modified way was defined, the aim was to provide reference of theory and examination for further design and engineering application on weathered rock of expressway roadbed construction.


2021 ◽  
Vol 11 (4) ◽  
pp. 1620
Author(s):  
Mohsin Usman Qureshi ◽  
Maryam Alsaidi ◽  
Mubashir Aziz ◽  
Ilhan Chang ◽  
Ali Murtaza Rasool ◽  
...  

Managing sediments dredged from reservoirs of recharge dams is an environmental issue, however, these sediments can be an abundant and economical source of fine-grained fill soil. This experimental investigation quantifies the geotechnical properties of a reservoir sediment used to improve engineering properties of a poorly graded dune sand in Oman. The binary mixes were prepared with different percentages (5, 10, 20, 50, 75, 90, 95%) of sediment with sand. Laboratory tests such as gradation, consistency limits, compaction, and unconfined compression tests were performed to measure the engineering characteristics of the binary mixtures. The results showed that the maximum dry density increases up to a sediment content of 50% and then decreases with further increase in the sediment content. The optimum water content increases with the increase in sediment content from 17% for pure sand to 22.5% for pure sediment. The optimum moisture content shows a good correlation with the plastic limit of the binary mixture of sand and sediment. The unconfined compressive strength substantially increases with sediment content up to 75% and then decreases with further increase in the sediment content. The binary mixture of sand sediment is sensitive to moisture, however, the order of strength stability against moisture is dune sand mixed with 75, 50, and 20% sediments. The addition of sediment to dune sand improved the uniformity coefficient to some extent with an increase in the maximum and minimum void ratios as well. The elemental analysis of the sediment confirms that the material is non-contaminated and can be employed in geotechnical engineering applications as a sustainable and environmentally friendly solution.


2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
Qu Jili ◽  
Wang Junfeng ◽  
Batugin Andrian ◽  
Zhu Hao

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.


2015 ◽  
Vol 72 (3) ◽  
Author(s):  
Siaw Yah Chong ◽  
Khairul Anuar Kassim

Marine clay is a problematic construction material, which is often encountered in Malaysian coastal area. Previous researchers showed that lime stabilization effectively enhanced the engineering properties of clay. For soft clay, both strength and consolidation characteristics are equally important to be fully understood for design purpose. This paper presented the effect of lime on compaction, strength and consolidation characteristics of Pontian marine clay. Compaction, unconfined compression, direct shear, Oedometer and falling head permeability tests were conducted on unstabilized and lime stabilized samples at various ages. Specimens were prepared by compaction method based on 95 percent maximum dry density at the wetter side of compaction curve. It was found that lime successfully increased the strength, stiffness and workability of Pontian marine clay; however, the permeability was reduced. Unconfined compressive strength of stabilized soil was increased by 49 percent at age of 56 days whereas compressibility and permeability was reduced by 48 and 67 percent, respectively. From laboratory tests, phenomenon of inconsistency in engineering characteristics was observed for lime stabilized samples below age of 28 days. This strongly proved that lime stabilized soil underwent modification phase before stabilization phase which provided the long term improvement.


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.


The aim of the present study is to determine the physical and geotechnical characteristics of municipal solid waste (MSW) from an open dump site located in Una town, Himachal Pradesh (India) for the analysis of settlement and structural stability of landfill. Degraded waste was tested for different time intervals ranging from 6 months to 6 years. The physical characterization and the geotechnical tests were performed to determine the composition and the engineering properties of MSW respectively. The presence of moisture content in the fresh waste was 49.5±1.05% but for the degraded (or old) waste it varied between 39.8 to 51.6%. The specific gravity of fresh and old waste varied between 1.83±0.05 and 1.85 for 6 months old waste and 2.28 for 5-6 years old degraded waste respectively. The maximum dry density (MDD) was observed to be 4.28 kN/m2 for fresh waste at the optimum moisture content (OMC) of 78.1% and 4.47 kN/m3 for 6 months old waste and 6.25 kN/m3 for the degraded waste of 5-6 years at 80.2, 85.4% of OMC respectively. The hydraulic conductivity (k) of MSW was found to be decreasing with the degradation of MSW and the overburden pressure whereas the shear strength increased along with the degradation of the waste. The cohesion (c) and angle of internal friction (φ) increased respectively from 31.2 kPa(fresh) to 38 kPa(degraded) and 14° to 22° with the increase in waste degradation. The compression ratio of fresh waste was within the ranges of 0.19-0.29 and for degraded MSW it varied between 0.12 for 6 months old waste and 0.17 for 5-6 years old degraded waste respectively.


2019 ◽  
Vol 969 ◽  
pp. 327-334
Author(s):  
C. Jairaj ◽  
M.T. Prathap Kumar ◽  
H. Muralidhara

This BC Soil are expansive in nature and are problematic because of low shear strength and high compressibility. Review of literatures have proven that addition of lime imparts high strength with a corresponding reduction in swell of BC soils. In addition, Bio-enzymes have also been found to play a key role as activators in improving the characteristics of clayey soils such as BC soil. Development and use of non-traditional ground improvement techniques such as bio-enzymes in combination with lime for soil stabilization helps to reduce the cost and the detrimental effects on the soil environment. In the present study lime and bio-enzymes were used as soil stabilizing agents. Compaction test results on BC soil admixed with different percent of lime indicated that 3% addition lime gives higher maximum dry density of 17kN/m3 with OMC of 21% compare to other addition of lime percentages. Keeping 3% of lime as optimum lime content(OLC), BC Soil was admixed with different dosages of Bio-enzymes 25ml/m3, 50ml/m3, 100 ml/m3,150ml/m3, and 200ml/m3 along with OLC was tested for compaction and unconfined compressive strength(UCC). Further UCC test was carried out for different curing period of 0, 7, 15, 30, and 60 Days to analyse the long term effect of BC soil admixed with bio-enzymes with and without lime content. Morphological and chemical analysis was done by using XRD and SEM analysis, from all the test results it was found that 3%OLC + 75ml/m3 of bio-enzymes for 7 day of curing gives higher UCC of 450 kPa. From the SEM it was found that better bond between particles found to develop in bio-enzyme+ lime admixed BC soil in comparison with lime alone admixed BC soil. XRD studies indicated morphological changes in crystallinity and structure of stabilized BC soil in comparison to BC soil alone.


2002 ◽  
Vol 39 (6) ◽  
pp. 1341-1357 ◽  
Author(s):  
Jean-Marie Fleureau ◽  
Jean-Claude Verbrugge ◽  
Pedro J Huergo ◽  
António Gomes Correia ◽  
Siba Kheirbek-Saoud

A relatively large number of drying and wetting tests have been performed on clayey soils compacted at the standard or modified Proctor optimum water content and maximum density and compared with tests on normally consolidated or overconsolidated soils. The results show that drying and wetting paths on compacted soils are fairly linear and reversible in the void ratio or water content versus negative pore-water pressure planes. On the wet side of the optimum, the wetting paths are independent of the compaction water content and can be approached by compaction tests with measurement of the negative pore-water pressure. Correlations have been established between the liquid limit of the soils and such properties as the optimum water content and negative pore-water pressure, the maximum dry density, and the swelling or drying index. Although based on a limited number of tests, these correlations provide a fairly good basis to model the drying–wetting paths when all the necessary data are not available.Key words: compaction, unsaturated soils, clays, drying, wetting, Proctor conditions.


2021 ◽  
Vol 6 (2) ◽  
pp. 044-050
Author(s):  
Tsion Mindaye ◽  
Emer Tucay Quezon ◽  
Temesgen Ayna

Expansive soil swells when it is wet, and it will shrink when it dries. Due to this behavior of the soil, the strength and other properties of soil are inferior. To improve its properties, it is necessary to stabilize the soil with different stabilizers. Soil stabilization is a process to treat the soil to maintain, alter, or improve expansive soil performance. In this study, the potential of 'Fino' as stabilizing additive to expansive soil was investigated for the improving engineering properties of expansive soil to be used as subgrade material. The evaluation involved the determination of the Free Swell test, CBR test, Atterberg's limits, and the Proctor test of expansive soil in its natural state as well as when mixed with varying proportions of 'Fino.' The practices were performed on six proportions 5%, 10%, 15%, 20%, 25% and 30 % with expansive soil. The research result indicated a considerable reduction in Swelling, and the Maximum dry Density of soil was improved. Optimum moisture content decreased in increasing 'Fino.' At 30% of 'Fino,' the CBR values of expansive soil increased from 1.06% to 5.94%, Liquid Limit decreased from 95.2% to 29.4%, plasticity index decreased from 57.24% to 17.82% and the degree of expansion of the natural subgrade soil has reduced from "very high to medium." Hence, it is concluded that the 'Fino' at 30% has shown significant improvement in the expansive soil's engineering properties meeting the ERA and AASHTO Standard specifications requirements for road subgrade material.


Sign in / Sign up

Export Citation Format

Share Document