Assessment of Recycled Gypsum for Organic Soft Clay Soil Improvement

2012 ◽  
Author(s):  
Aly Ahmed ◽  
Keizo Ugai ◽  
Takeshi Kamei
Keyword(s):  
Clay Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Recycled Gypsum

Effects of Electro Osmotic Consolidation in South West of Johor: Small Laboratory Scale

2014 ◽  
Vol 803 ◽  
pp. 255-264
Author(s):  
Khairul Nizar Mohd Yusof ◽  
Fauziah Ahmad ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Muhammad Faheem Mohd Tahir
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Clay Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Undrained Shear Strength ◽  
Engineering Structures ◽  
Vertical Loading ◽  
South West ◽  
Undrained Shear

Clay soil is one of the problematic soils due to its natural states which have low bearing capacity and high compressibility. The effect and problem of the clay soil characteristic creates a problem for construction especially excessive settlement and this can lead to unstable and potential cracks of engineering structures. At presents, there are few of soil improvement types can be carried out to overcome these problems, and electro osmotic consolidation is one of the options. This method has been applied many years ago especially in european countries. The study encompasses the determination of water content, atterberg’s limits and undrained shear strength after electro osmotic consolidation treatment of clay soils taken from 0.5 m and 1.5 m at southwest part of johor. All the samples were tested according to BS1377:1990. An experimental study was implemented in a pvc cylinder tube having dimensions of 300 mm height and 100 mm diameter. In the results of electro osmotic consolidation tests by installing copper spring electrodes, the measured undrained shear strength was increased considerably at the anodes especially compared to the initial undrained shear strength due to electro osmosis process and consolidation. As laboratory studies of its measurement have shown, the application of electro osmotic consolidation after the application of a direct current applied voltage of 10 volts, at the anodes especially: (i) a decrease by approximately 35% in water content; (ii) an increase around 29% in undrained shear strength; and (iii) a decrease about 21% in index plasticity. The results obtained in this study shows that the electro osmotic enhanced 15 kpa vertical loading consolidation is a feasible approach in strengthening of south west soft clay in johor. It can be clearly suggested that the higher the voltage applied in the system, the higher readings of undrained shear strength and the lower of water content especially at the anodes.

scholarly journals Analisis Vacuum Consolidation pada Perbaikan Tanah Lempung Lunak dengan Model Axisymmetric (Hal. 68-79)

2018 ◽  
Vol 4 (1) ◽  
pp. 68
Author(s):  
Nadya Utami Rivanga ◽  
Indra Noer Hamdhan
Keyword(s):  
Shear Strength ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Vacuum Consolidation ◽  
Final Project ◽  
Vertical Drain ◽  
Soil Model ◽  
Low Shear

ABSTRAKTanah lempung lunak merupakan jenis tanah yang memiliki kuat geser yang kecil, koefisien permeabilitas yang kecil, kompresibilitas yang besar, dan mempunyai daya dukung rendah. Kondisi tersebut menyebabkan tanah lempung lunak menjadi tantangan pada kontruksi yang akan di bangun diatasnya, sehingga diperlukan perbaikan tanah. Salah satu perbaikan tanah untuk tanah lempung lunak yang banyak dijumpai yaitu vertical drain dan preloading. Pada tugas akhir ini metode tersebut akan dikombinasikan dengan vacuum consolidation. Tegangan vakum yang digunakan pada kasus ini sebesar 50 dan 80 kPa. Analisis yang dilakukan dengan menggunakan program PLAXIS 2D dengan model Axisymmetric. Analisis dilakukan dengan memvariasikan tiga dari sekian banyak soil model yaitu Mohr Coulomb, Hardening Soil, dan Soft Soil. Berdasarkan hasil dari penelitian nilai penurunan, tegangan pori, dan waktu konsolidasi yang dihasilkan berbeda tetapi hasil penurunan soil model dengan Hardening Soil dan Soft Soil tidak terlalu berdeda secara signifikan.Kata Kunci: tanah lempung lunak, vacuum consolidation, Mohr Coulomb, Hardening Soil, Soft Soil, axisymmetric, PLAXIS 2D  ABSTRACTSoft clay is a type of soil that has low shear strength,  high compressibility,  low coeffiecient of permeability and low bearing capacity. The condition caused soft clay soil to be a challenge on the construction that will be built on it, so that it needed soil improvement. The soil improvement for soft clay that often found is vertical drain and preloading. In this final project that method will be combined with vacuum consolidation. The vacuum pressure used in this case amount from 50 and 80 kPa. The analysis was performed using PLAXIS 2D program with Axisymmetric model. The analysis was done by varying the three of soil models Mohr Coulomb, Hardening Soil, and Soft Soil. Based on the settlement of the research, settlement value, pore pressure, and time of consolidation are different but the result of soil models of Hardening Soil and Soft Soil is not significantly differentiated.Keywords: soft clay, vacuum consolidation, Mohr Coulomb, Hardening Soil, Soft Soil, axisymmetric, PLAXIS 2D

scholarly journals The behaviour of the clay soil reinforced by stone column encased with geogrid under cyclic load

2018 ◽  
Vol 1 ◽  
pp. 33-38
Author(s):  
Kwa S.F. ◽  
Kolosov E.S.
Keyword(s):  
Bearing Capacity ◽  
Cyclic Load ◽  
Clay Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Stone Columns ◽  
Excess Pore Pressure ◽  
Stone Column ◽  
Foundation Soil ◽  
Saturated Clay

The behavior of the fully saturated clay soil reinforced by stone columns subjected to cyclic load is of considerable very important in the design of railway subgrades, these soft clay soil are characterized by high settlement and low bearing capacity because of the excess pore pressure due to heavy freight trains significantly reduces the bearing capacity which causes serious problems, the used of stone column for reinforced the saturated clay soil will reduced the settlement and increase the bearing capacity. The purpose of the current research is cases study of foundation soil improvement by reduced the settlement for a building structure using stone columns system with and without geogrid encasement under cyclic load with rate of loading 5 mm/sec.

Uplift and Settlement Prediction Model of Marine Clay Soil e Integrated with Polyurethane Foam

2019 ◽  
Vol 9 (1) ◽  
pp. 481-489
Author(s):  
D.C. Lat ◽  
I.B.M. Jais ◽  
N. Ali ◽  
B. Baharom ◽  
N.Z. Mohd Yunus ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Clay Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soft Clay ◽  
Effective Thickness ◽  
Marine Clay ◽  
Uplift Pressure ◽  
Pu Foam ◽  
Improvement Method

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.

Experimental Research on the Engineering Properties of Foam-Improved Red Clay Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1831-1835
Author(s):  
Guo Gang Qiao ◽  
Da Jun Yuan ◽  
Bo Liu
Keyword(s):  
Experimental Research ◽  
Clay Soil ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Screw Conveyor ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shield Tunneling ◽  
Red Clay ◽  
Improvement Measures

Red clay soil is widely distributed in south China, the microstructure of red clay soil was studied applying scanning electron microscopy (SEM), and the X-ray diffraction analysis (XRD) test found that a large number of swelling inducing minerals, for example, montmorillonite, illite-montmorillonite or chlorite-smectite were contained in the red clay soil. Shield tunneling in this kind of stratum is prone to arising “cake” and “arch” phenomena and it prone to lead screw conveyor device unsmooth dumping, so soil improvement measures must be taken. Foam as the most advanced soil conditioner has been widely used in shield construction. Using self-developed foam agent, experimental research on foam conditioning red clay soil was carried out, test results show that foam can not only significantly reduce the soil shear strength, but also can greatly enhance the soil's compressibility and fluidity, which is significant for the smooth dumping and excavation face stability maintenance.

scholarly journals ANALYSIS OF TWO ADJACENT TUNNELS IN SOFT CLAY SOIL

2012 ◽  
Vol 15 (1) ◽  
pp. 211-222
Author(s):  
G Attia ◽  
E Elshamy ◽  
H Fawzy ◽  
K Abdul - hafez
Keyword(s):  
Clay Soil ◽  
Soft Clay

scholarly journals Design Charts for Axially Loaded Single Pile Action

2019 ◽  
Vol 5 (4) ◽  
pp. 922-939 ◽  
Author(s):  
Anis Abdul Khuder Mohamad Ali ◽  
Jaffar Ahemd Kadim ◽  
Ali Hashim Mohamad
Keyword(s):  
Clay Soil ◽  
Skin Resistance ◽  
Soft Clay ◽  
Single Layer ◽  
Load Test ◽  
Engineering Properties ◽  
Single Pile ◽  
Dense Sand ◽  
Design Charts ◽  
Pile Length

The objective of this article is to generating the design charts deals with the axially ultimate capacity of single pile action by relating the soil and pile engineering properties with the pile capacity components. The soil and are connected together by the interface finite element along pile side an on its remote end.  The analysis was carried out using ABAQUS software to find the nonlinear solution of the problem. Both pile and soil were modeled with three-dimensional brick elements. The software program is verified against field load-test measurements to verify its efficiency accuracy. The concrete bored piles are used with different lengths and pile diameter is taken equals to 0.6 m. The piles were installed into a single layer of sand soil with angles of internal friction (20° t0 40°) and into a single layer of clay soil with Cohesion (24 to 96) kPa.  The getting results showed that for all cases study the total compression resistance is increased as pile length increased for the same property of soil, also illustrious that the total resistance of same pile length and diameter increased as the soil strength increasing. In addition, the same results were obtained for the end bearing resistance, skin resistance and tension capacity. Design charts were constructed between different types of soil resistance ratio and the pile length/diameter ratio (L/D) for all cases of study. One of improvement found from these curves that it is cheaply using piles of larger diameter than increasing their lengths for dense sand and to increasing piles lengths for loose sand. Moreover, it is inexpensively using piles of larger length in soft clay soil than increasing their diameter and piles of larger diameter in firm and stiff clay soils than increasing their length.

Sign in / Sign up

Export Citation Format

Share Document