scholarly journals Peningkatan Daya Dukung Pondasi pada Tanah Lempung dengan Perkuatan Kolom Tanah

CANTILEVER ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 69-74
Author(s):  
Ratna Dewi ◽  
Hanafiah ◽  
Ridho Ustadi

One of the problematic soils for construction if the soil is used as a foundation for a construction is clay soil which has relatively low shear strength and bearing capacity. Therefore, it needs an improvement effort to increase the strength of the clay soil. The reinforcement soil column is an alternative effort to improve the soil. This paper presents the results of laboratory-scale experimental on the reinforcement modelling of clay soil columns mixed with 6% rice husk ash (RHA). Modelling was carried out with 6 variations of column groups with constant column length of 67cm. The first three variations are the variation in the distance between columns (s/d) with a fixed diameter of 8 cm. The other three variations are column diameter variations with a fixed s/d ratio. The results showed that the larger the distance between the columns, the smaller the bearing capacity of the soil foundation. If the s/d ratio is constant, it is found that the larger the column diameter, the greater the bearing capacity of the soil foundation. The maximum ultimate bearing capacity of the soil is achieved in variations with a column diameter of 12cm and a distance between columns of 30cm (s/d = 2.5) with a value of 39.56 kPa. This bearing capacity provides a BCR value of 3.75% or almost 4 times the bearing capacity of the unreinforced foundation.

INFO-TEKNIK ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 41
Author(s):  
Ayu Purnama Sari ◽  
M. Ikhwan Yani ◽  
Suradji Gandi

Clay soil is a cohesive soil with low bearing capacity and low shear strength where the load on it will be limited. The addition of water content in clay soil will result in changes in soil volume that will affect the strength of the soil. The research aims to know how much water content affects the values of consolidation settlement. A consolidation test was carried out three times with variations of the original soil sample, 35% water content and 30% water content. The results obtained a settlement of 0,1864 cm for original water content, 0,1677 cm for 35% water content, and 0,1414 cm for 30% water content.


2018 ◽  
Vol 7 (4.36) ◽  
pp. 424 ◽  
Author(s):  
Maxwel Joseph Henri Nainggolan ◽  
Wiwik Rahayu ◽  
Puspita Lisdiyanti

In recent years, utilization of biotechnology in geotechnical field has rapidly grown. One of the biotechnologies being utilized is urease enzyme, a stabilization material by bio-cementation method studied in this research.  Urease enzyme is manually mixed with additional 10% of clay soil to clay shale. The objective of mixing it is to increase the bearing capacity of the clay shale. Consolidated undrained triaxial test was performed for testing the soil strength performance for samples that had undergone curing for 2, 4, and 6 weeks. The results indicated that the sample stiffens, proved by the increase of shear strength from consolidated undrained triaxial test. The shear strength value produced by the variation of the urease enzyme mixture + 10% the clay is higher than that of without the original clay shale.  


2018 ◽  
Vol 4 (3) ◽  
pp. 594 ◽  
Author(s):  
Davood Akbarimehr ◽  
Esmael Aflaki

With respect to the increasing production of tire wastes, the use of these wastes as an additive in civil engineering has always gained attentions of researchers due to their positive effects on material properties and reduction of environmental problems. Clay soils, as problematic soils, have always caused geotechnical problems including high Atterberg limits and consequently low workability. Tire powder, as one of the products of tire wastes, lacks clay cohesion and it can be effective in altering the plasticity of clay soils. As no comprehensive study has been conducted in this regard specifically on Tehran clay soil yet, this research studies experimentally the effect of adding different percentages of tire powder to clay soil at the Atterberg limits of clay soils with two different types of plasticity. More over according to previous studies, the effect of tire powder on other geotechnical properties of clay soils and the advantages and disadvantages of using tire powder in clay soils are discussed. The results indicate that addition of tire powder to clay soils has positive effects on reducing the Atterberg limits, increasing efficiency, and improving resistance, permeability, swelling reduction, and settlement properties, and reducing soil density and it can be used as an additive in improving clay soils.


2019 ◽  
Vol 37 ◽  
Author(s):  
K.F. MENDES ◽  
A.T. SHIROMA ◽  
R.F. PIMPINATO ◽  
M.R. REIS ◽  
V.L. TORNISIELO

ABSTRACT: Adjuvants, such as mineral oils, are widely used in the application of herbicides by reducing the drift and evaporation of the droplets and by increasing herbicide uptake by the plant. However, little is known about how mineral oil behaves when in contact with the soil. Thus, the objective of this research was to evaluate the transport of atrazine via leaching with the addition of mineral oil in a soil agricultural under laboratory conditions. To quantify the concentration of the herbicide along the profile of the very clay soil column (30 cm), 14C-atrazine (ring-U-14C) was used with 16,667 Bq of radioactivity per column in volume of 200 mL solution and 0 (control), 1, and 2% mineral oil (v/v) was added in the application volume. Atrazine was applied at the highest commercial dose recommended for sugarcane (4 kg ha-1). After simulation of a precipitation of 200 mm for 48 h, each column was sectioned into six parts of 5 cm and the analytes of each soil sample and the leachate were quantified by liquid scintillation spectrometry. The atrazine remained in the superficial layer of the soil, between 0 and 10 cm of depth, independent of the addition of mineral oil. No atrazine residues were detected in the leachate solution (> 30 cm) in any evaluated treatment. The addition of mineral oil at the time of application of pre-emergence atrazine did not interfere with the transport of this herbicide in the soil profile agricultural via leaching; therefore, the adjuvant may have positive effect only in the herbicide-plant relationship.


2014 ◽  
Vol 6 (2) ◽  
pp. 2675-2697
Author(s):  
A. Galsa ◽  
M. Herein ◽  
L. Lenkey ◽  
M. P. Farkas ◽  
G. Taller

Abstract. Numerical modeling has been carried out in a 2-D cylindrical shell domain to quantify the evolution of a primordial dense layer around the core mantle boundary. Effective buoyancy ratio, Beff was introduced to characterize the evolution of the two-layer thermo-chemical convection in the Earth's mantle. Beff decreases with time due to (1) warming the compositionally dense layer, (2) cooling the overlying mantle, (3) eroding the dense layer by thermal convection in the overlying mantle, and (4) diluting the dense layer by inner convection. When Beff reaches the instability point, Beff = 1, effective thermo-chemical convection starts, and the mantle will be mixed (Beff = 0) during a short time. A parabolic relation was revealed between the initial density difference of the layers and the mixing time. Morphology of large low shear velocity provinces as well as results from seismic tomography and normal mode data suggest a value of Beff ≥ 1 for the mantle.


2012 ◽  
Vol 203 ◽  
pp. 325-328
Author(s):  
Xin Jie Chu

This paper analyzes the stability and structural optimization of self-elevating platform pile foundation, preliminarily discusses the method of analyzing the bearing capacity of the layer soil foundation, and establishes the numerical computation models for the whole platform, pile, pile shoe, etc. Besides, through these analyses, the pile structure is optimized, and the stress concentration in the joint between pile and pile shoe is reduced. Also, this study is of reference value for the analysis on the self-elevating platform pile foundation design and the platform operation stability.


PLoS ONE ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. e0229532 ◽  
Author(s):  
Huang Zhanfang ◽  
Bai Xiaohong ◽  
Yin Chao ◽  
Wang Yanping

1995 ◽  
Vol 32 (1) ◽  
pp. 40-59 ◽  
Author(s):  
Abdel M.O. Mohamed ◽  
Raymond N. Yong ◽  
Miroslawa T. Mazus

In this study, the effect of temperature distribution and its influence on contaminant migration in a silty clay soil were examined. Three series of freezing-column tests were performed with three different fluids: distilled water, municipal waste leachate, and heavy metal – leachate solution. It was found that temperature distribution as a function of space and time was similar in all tests, most likely as a result of the limited amount of fluid intake. Moisture redistributions were varied as a function of experiment duration and the type of fluid used. The amount of fluid intake was directly related to the freezing time and the temperature gradient in the freezing column. The amount of unfrozen water content, ion concentration and temperature gradient were the controlling parameters that contributed to the contaminant transport in the frozen illitic silty clay soil. Na+-concentration profiles were mostly dependent on water movement in the soil column. The behaviour of Ca2+ and Mg2+ cations was similar to Na+; their concentrations in the soil solution decreased with freezing time due to ion exchange. The large accumulations of Pb2+, Zn2+, Cu2+, and Cd2+ in the lower 10 mm of the soil column occurred as a result of cation exchange and precipitation mechanisms. Key words : unsaturated, osmotic, diffusion, buffer, exchange, transport.


2013 ◽  
Vol 353-356 ◽  
pp. 337-340
Author(s):  
Ying Hao Wang ◽  
Yu Qin Feng ◽  
Shuo Li

By uniting composite foundation with CFG pile composite foundation for a practical engineering project in Baotou, the bearing capacity of CFG pile in sandy soil and silty soil foundation were analyzed. The conclusion can be applied to the similar projects in the region of Inner Mongolia.


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