scholarly journals Tropical Residual Soil Properties on Slopes

Author(s):  
M.F. Ishak ◽  
M.F. Zolkepli ◽  
M. Affendy

Tropical residual soil is a product of chemical weathering, thus its characteristics are dependent upon environmental factors such as parent rocks, climate, topography and age. This type of soil can be found in many countries all over the world, especially in the tropical region. Since there are many accident happens due to slope failure, a comprehensive laboratory study need to be conducted in order to determine the properties of soil located at Pahang Matriculation College. Several experiments involving physical index and engineering properties of soil are conducted. The typical tropical residual properties are showed and can be considered as sandy SILT of high plasticity.

Author(s):  
Burak Boluk ◽  
Anand J. Puppala ◽  
Sayantan Chakraborty ◽  
Puneet Bhaskar

A comprehensive investigation was designed and conducted to identify the potential causes of failure of a highway embankment slope in Texas and evaluate the effectiveness of lime treatment to rehabilitate the failed slope. Highway slopes built with high plasticity clays often experience shallow slope failures after exposure to repeated wet–dry weathering cycles. Lime stabilization generally reduces the swell–shrink potential, enhances the engineering properties of problematic clayey soils, and can potentially prevent surficial slope failures. However, exposure to wet–dry cycles can negate some of the benefits of lime treatment and therefore a study was conducted to address the use of this lime treatment to stabilize embankment slopes. Extensive laboratory tests were conducted to study the effect of weathering cycles on the degradation of hydro-mechanical properties of untreated and lime-treated soils. Rainfall-induced slope stability analyses were performed to investigate the probable causes of slope failure and evaluate the stability of lime-treated surficial slope. The optimum stabilizer dosage and treated layer thickness required for the slope rehabilitation were determined based on laboratory tests and numerical analysis results. The stability analysis results indicate that the degradation of surficial soil’s hydro-mechanical properties and the development of a perched water table during prolonged rainfall possibly caused the slope failure. The post-treatment increase in shear strength properties, reduction in moisture fluctuations recorded by embedded moisture sensors, and the presence of newly installed underlying drains are expected to prevent recurrence of surficial slope failures. Salient results from this study are covered in this paper.


2014 ◽  
Vol 501-504 ◽  
pp. 359-367
Author(s):  
Feng Zhou ◽  
Kai Zhang ◽  
Ying Chun Tang

This paper summarizes and analyzes the basic concepts and ecological protection mechanism for expansion geotechnical slope failure mechanism and the resulting impact on the shallow, traction engineering properties such as analysis, proposed ecological slope of expansive soil slope mechanism of action: vegetation system by improving internal slope soil moisture and temperature changes affect the atmosphere and thus effectively reduce the depth. Vegetation root through reinforced anchoring, delay time and improving soil hydration ductility such as the role played good strength enhancement. Vegetation formation can effectively improve the damaged outer slope interface morphology, to restore the ecological environment and landscape effect. Integrating the past experience on expansive soil slope treatment, this paper provide a slope treatment method used in Nanning metro Tunli section, these will provide reference for the expansive soil slope ecological management.


Author(s):  
Ishowriya Yumnam

In this review article the usage of waste sewage sludge and the biomass ash for improving the engineering and non-engineering properties’ of both concrete and soil are discussed in detail. Numerous past research works were studied in detail so as to predict the behavior of biomass ash and waste sewage sludge when used for the stabilization process of soil and concrete. Past studies related to the usage of stabilized sewage sludge and biomass ash were studied in a detailed manner and depending upon the past studies several conclusions has been drawn which are discussed further. Several studies related to the usage of the waste sewage sludge for improving soil physical, chemical and biological properties showed that the usage of waste sewage sludge improve the physical properties, chemical properties, macro-nutriential properties and micro-nutriential properties up to a great extent. Depending upon the results of the past studies it can be concluded that the usage of sewage sludge has positive impact over all the properties of soil and this waste should be utilized in improving the properties of soil rather than dumping. Numerous studies related to the usage of the biomass ash showed that biomass ash has positive impact over both soil as well as concrete. Studies related to the usage of the biomass ash in soil showed that there was a positive response of the stabilized soil after its stabilization with the biomass ash. Studies related to the usage of the biomass ash in concrete showed that the biomass ash can be used up to 10 percent replacement of the ordinary Portland cement so as to attain maximum strength results from it.


Author(s):  
Khelifa Harichane ◽  
Mohamed Ghrici ◽  
Said Kenai

Cohesive soils with a high plasticity index present difficulties in construction operations because they usually contain expansive clay minerals. However, the engineering properties of soils can be improved by different techniques. The aim of this paper is to study the effect of using lime, natural pozzolana or a combination of both lime and natural pozzolana on plasticity, compaction and shear strength of two clayey soils classified as CH and CL according to the unified soil classification system (USCS). The obtained results indicated that for CH class clay soil, the plasticity index decreased significantly for samples stabilized with lime. On the other hand, for the soil classified as CL class clay, a high decrease in the plasticity index value was observed for samples stabilized with natural pozzolana compared to those stabilized with lime. Also, both the cohesion and internal friction angle in lime added samples were demonstrated to increase with time. The combination of lime and natural pozzolana exhibits a significant effect on the enhancement of both the cohesion and  internal friction angle at later stages. The lime-natural pozzolana combination appears to produce higher shear strength parameters than lime or natural pozzolana used alone.


Author(s):  
Prerna Priya ◽  
Ran Vijay Singh

Expansive Black cotton clay soils are widely distributed worldwide, and are a significant damage to infrastructure and buildigs.It is a common practice around the world to stabilize black cotton soil using fly ash to improve the strength of stabilized sub- base and sub grade soil. Soil stabilization is the improvement of strength or bearing capacity of soil by controlled compaction, proportioning or addition of suitable admixtures or stabilizers. The Black cotton soils are extremely hard when dry, but lose its strength fully when in wet condition. In monsoon they guzzle water and swell and in summer they shrink on evaporation of water from there. Because of its high Swelling and shrinkage characteristics the black cotton soils has been a challenge to the highway engineers.So in this research paper fly ash has been used to improve the various strength properties of natural black cotton soil.The objective of this research paper is to improve the engineering properties of black cotton soil by adding different percentage of fly ash by the weight of soil and make it suitable for construction. A series of standard Proctor tests (for calculation of MDD and OMC) and California Bearing Ratio (C.B.R) tests are conducted on both raw Black cotton soil and mixed soil with different percentages of fly ash (5%, 10%, 20%, 30%) by weight. A comparison between properties of raw black cotton soil, black cotton soil mixed with fly ash are performed .It is found that the properties of black cotton soil mixed with fly ash are suitably enhanced.


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