SOFT SOIL IMPROVEMENT USING CHEMICAL-RUBBER CHIPS MIXTURE

2015 ◽  
Vol 76 (2) ◽  
Author(s):  
Aminaton Marto ◽  
Norazirah Aziz ◽  
Mohammed Ridzuan Jahidin ◽  
Nor Zurairahetty Mohd Yunus ◽  
Fauziah Kasim ◽  
...  

Soft soils are widely found in many areas around the world as well as in Malaysia. Marine clay is one of the problematic soft soils. The marine clay should be pretreated before the construction to enhance the usability and serviceability of highway constructed on this type of soil. This paper presents the research results on the usability of chemical (SH-85)-rubber chips mixtures as the stabilizing agent in improving the characteristics of marine clay from two engineering perspectives; the strength and the compressibility. Three types of laboratory tests were conducted; index soil test, unconfined compression test and oedometer test. The results show that the treated samples had higher unconfined compressive strength compared to untreated sample. The strength of marine clay increased when the amount of the SH-85 increased.  The void ratio reduced in value when the chemical-rubber chips mixture was added to the marine clay. It is due to the chemical that acts as a binder that interlocks the rubber chips and the marine clay particles, reducing the compressibility. It has been concluded that the mixture of chemical-rubber chips with 8 % SH-85 plus 1 % of rubber chips is more effectively improved the characteristics of marine clay.  

2019 ◽  
Vol 8 (2) ◽  
pp. 63-70
Author(s):  
Dyah Pratiwi Kusumastuti ◽  
Irma Sepriyanna Sepriyanna

It can not be avoided when the construction must stand on soft soil, then the construction will suffer damage due to subsidence or congestion from soft soil. To improve soft soils as one part of the construction of them is the method of chemical stabilization of the soil. The stabilizer material mixed was 10% glass powder and the percentage of husk ash was 0%, 2.5%, 5%, 7.5% and 10% of the dry weight of the original soil sample. Changes in the characteristics of soft soil and stabilized soils are reviewed based on the consolidation test. Based on the results of the study, the value of the void ratio decreases with increasing glass dust and husk ash, where the lowest void ratio is 0.5328 obtained in the addition of 10% glass powder and 7.5% husk ash. A decrease in the void ratio indicates a decrease in the compression index (Cc) and the swelling index (Cs). The lowering of the compression index and the swelling index indicate that the addition of glass powder and husk ash causes the soft soil sample to become denser. The lowest compressive index and swelling index values ​​were obtained in soil sample specimens with the addition of 10% glass powder and 10% husk ash, which respectively decreased by 35.165% and 75.757% when compared to the condition of the original soil sample.


2018 ◽  
Vol 195 ◽  
pp. 03006
Author(s):  
Ega Dhianty ◽  
Indrasurya B. Mochtar

Due to external loads, the soft soil will undergo a large compression of both primary and secondary compression. With soil improvement using prefabricated vertical drain (PVD), the time of primary compression becomes shorter so that secondary compression occurs in short time. There has been little research on how to remove secondary compression. Therefore, further investigation of behaviour and method of removing secondary compression is necessary. This research was conducted based on an experimental study of clay consolidation test with a variation of loading time in the laboratory. The results show that there is an empirical correlation among the secondary compression index (Cα’), the initial void ratio (e0), the void ratio at the end of primary consolidation (ep), and the effective consolidation stress (P’). The correlations obtained from this study are Cα’ = (0.0072e0 - 0.0067)P’ and Cα’ = (0.0077ep - 0.006)P’. The greater the effective consolidation stress is, the greater the secondary compression index will become. Therefore, in soil improvement secondary compression can be removed by giving an extra load (Δq) that causes additional compression to the primary consolidation where the magnitude equals to the expected secondary compression. Then, this Δq could be removed at the end of the primary consolidation.


2020 ◽  
Vol 6 (12) ◽  
pp. 2363-2374
Author(s):  
Erdawaty Erdawaty ◽  
Tri Harianto ◽  
A. B. Muhiddin ◽  
Ardy Arsyad

In civil engineering, alternative materials showed rapid progress. Asphalt derived from Buton Island in Indonesia, also known as Asbuton, was located in the limestone bedrock. A large deposit of Asbuton could guarantee the supply of alternative construction materials. In that regard, Asbuton performance as an alternative material to several subjects needs to be analyzed. Therefore, this study was conducted to analyze Asbuton’s behavior as a filler in a floating column model as a soft soil improvement concept. Asbuton added to sand and gravel mixture as filler and waterglass as a binder. CBR samples were tested to acquire the optimum composition with varied curing days namely 0, 3, and 7 days, following ASTM D-1883, followed by a compressive column model test which was based on ASTM D-2166. Finally, the column applied to the soft soil layer to be tested in a loading test, and the results are then compared for each composition. The results showed that the granular material's composition including Asbuton, the waterglass content, and the curing period significantly affect the engineering properties of the artificial column. The results revealed that the granular column with Asbuton with the addition of waterglass could increase soil’s load capacity and reduce the settlement of soft soils. Doi: 10.28991/cej-2020-03091623 Full Text: PDF


2020 ◽  
Vol 8 (6) ◽  
pp. 429 ◽  
Author(s):  
Sang Hyun Jun ◽  
Hyuk Jae Kwon

This paper proposes representative constitutive relationship equations of dredging and reclamation soft soil in Korea. The marine soft soils were sampled at 23 dredged-reclaimed construction sites in the Busan, Gwangyang, and Incheon regions in Korea; then, laboratory tests were carried out. The consolidation property was classified as LL = 60% for Busan and Gwangyang marine soft soil and LL = 30% for Incheon marine soft soil by conducting basic physical property tests and consolidation tests. Busan soft soil showed a slightly higher consolidation settlement property than Gwangyang soft soil. Incheon soft soil showed the lowest consolidation settlement property among the three regions. In particular, 77 consolidation simulations were carried out at a high void ratio using the centrifugal experiment to realize high water content and in-field stress conditions. The constitutive relationship equations of each of the 23 specimens were analyzed with regard to the void ratio–effective stress and void ratio–permeability coefficient through the back analysis of finite consolidation theory from the experimental results. The constitutive relationship equation for Korean soft soil was determined to be a reasonable power function equation. The representative constitutive relationships for soft soils in the three regions were estimated using six equations, which were classified by physical and consolidation properties. The representative constitutive equations were compared to those in previous studies on high void ratio conditions of marine soft soil, and the results showed a similar range.


2019 ◽  
Vol 9 (1) ◽  
pp. 481-489
Author(s):  
D.C. Lat ◽  
I.B.M. Jais ◽  
N. Ali ◽  
B. Baharom ◽  
N.Z. Mohd Yunus ◽  
...  

AbstractPolyurethane (PU) foam is a lightweight material that can be used efficiently as a ground improvement method in solving excessive and differential settlement of soil foundation mainly for infrastructures such as road, highway and parking spaces. The ground improvement method is done by excavation and removal of soft soil at shallow depth and replacement with lightweight PU foam slab. This study is done to simulate the model of marine clay soil integrated with polyurethane foam using finite element method (FEM) PLAXIS 2D for prediction of settlement behavior and uplift effect due to polyurethane foam mitigation method. Model of soft clay foundation stabilized with PU foam slab with variation in thickness and overburden loads were analyzed. Results from FEM exhibited the same trend as the results of the analytical method whereby PU foam has successfully reduced the amount of settlement significantly. With the increase in PU foam thickness, the settlement is reduced, nonetheless the uplift pressure starts to increase beyond the line of effective thickness. PU foam design chart has been produced for practical application in order to adopt the effective thickness of PU foam within tolerable settlement value and uplift pressure with respect to different overburden loads for ground improvement works.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthias Weber ◽  
Markus Alexander Rothschild ◽  
Anja Niehoff

AbstractCompared to articular cartilage, the biomechanical properties of costal cartilage have not yet been extensively explored. The research presented addresses this problem by studying for the first time the anisotropic elastic behavior of human costal cartilage. Samples were taken from 12 male and female cadavers and unconfined compression and indentation tests were performed in mediolateral and dorsoventral direction to determine Young’s Moduli EC for compression and Ei5%, Ei10% and Eimax at 5%, 10% and maximum strain for indentation. Furthermore, the crack direction of the unconfined compression samples was determined and histological samples of the cartilage tissue were examined with the picrosirius-polarization staining method. The tests revealed mean Young’s Moduli of EC = 32.9 ± 17.9 MPa (N = 10), Ei5% = 11.1 ± 5.6 MPa (N = 12), Ei10% = 13.3 ± 6.3 MPa (N = 12) and Eimax = 14.6 ± 6.6 MPa (N = 12). We found that the Young’s Moduli in the indentation test are clearly anisotropic with significant higher results in the mediolateral direction (all P = 0.002). In addition, a dependence of the crack direction of the compressed specimens on the load orientation was observed. Those findings were supported by the orientation of the structure of the collagen fibers determined in the histological examination. Also, a significant age-related elastic behavior of human costal cartilage could be shown with the unconfined compression test (P = 0.009) and the indentation test (P = 0.004), but no sex effect could be detected. Those results are helpful in the field of autologous grafts for rhinoplastic surgery and for the refinement of material parameters in Finite Element models e.g., for accident analyses with traumatic impact on the thorax.


2018 ◽  
Vol 53 ◽  
pp. 04021
Author(s):  
SHAO Yong ◽  
LIU Xiao-li ◽  
ZHU Jin-jun

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.


2021 ◽  
Vol 44 (4) ◽  
pp. 1-12
Author(s):  
Nima Alkhorshid ◽  
Gregório Araújo ◽  
Ennio Palmeira

The use of granular column is one of the ground improvement methods used for soft soils. This method improves the foundation soils mechanical properties by displacing the soft soil with the compacted granular columns. The columns have high permeability that can accelerate the excess pore water pressure produced in soft soils and increase the undrained shear strength. When it comes to very soft soils, the use of granular columns is not of interest since these soils present no significant confinement to the columns. Here comes the encased columns that receive the confinement from the encasement materials. In this study, the influence of the column installation method on the surrounding soil and the encasement effect on the granular column performance were investigated using numerical analyses and experimental tests. The results show that numerical simulations can reasonably predict the behavior of both the encased column and the surrounding soil.


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