Strength of Laterite Mixed with GeoPolySoilS for Slope Cover and Protection

Slope stabilization or slope protection is the actions constructed on the slope or nearby areas to keep the slope safe from moving water, erosion, or the negative impacts of sudden outflow. There are a few slope stabilization methods such as geometric method, hydrological method and chemical and mechanical method that can be used to enhance the engineering properties of laterite soil. Among these methods, the chemical method was proven to be a method that is efficient to enhance the geotechnical properties of laterite soil. In this study, GeoPolySoilS was used to mixed with laterite soil to increase the strength of the soil. This study is carried out to investigate the strength of the laterite mixed with GeoPolySoilS for slope cover and protection. For the physical and mechanical properties test, laboratory experiments were conducted on natural laterite soil to determine the natural moisture content, particle size distribution, liquid limit, plastic limit, maximum dry density, optimum moisture content and unconfined compressive strength of the soil. The amount of GeoPolySoilS applied to the laterite soil sample are 0%, 5%, 8%, 10%, 12%, 15%, 18% and 20%. The results of laboratory tests show that by adding an appropriate amount of GeoPolySoilS to the soil, the stability of the slope surface increases, thus able to avoid landslides

A review of polyurethane as a ground improvement method

Ground improvement based on lightweight materials is commonly applied as a method to overcome the problem related to excessive and differential settlement. The application of polyurethane (PU) as a ground improvement work currently increases in demand due to its well performance in many ground improvement projects. The properties and strength of different types of PU available in the market, together with the safety issues and precautions are highlighted in this paper. Due to its lightweight properties, buoyancy behavior of the lightweight foam often causes uplift which jeopardize the stability of the existing structure. Since it is applied in the ground, awareness on PU degradation needs to be emphasized. The suitability and applications of PU as one of alternative method for ground improvement works are also highlighted in this paper

Rehabilitation method of culvert foundation failure using polygeo foam

A concrete box culvert with a dimension of 2.1 x 2.1 m and a concrete pipe culvert of 0.9 m diameter founded on soft soil were experiencing soil settlement causing undulation and discomfort to the traffic users. Voids that appeared beneath the culvert foundations triggering the road surface to sag. Objectives of the study are to assess the settlement of culverts underlain by soft soil using PLAXIS simulations on the initial subsoil conditions, after rehabilitation works with Polygeo foam injection and to evaluate the performance of Polygeo foam as a rehabilitation method. The settlement of the culverts underlain by the soft soil will be determined using finite element model based on the data and information obtained from geoforensic assessments including 12 nos. of deep borehole as well as soil laboratory tests. There were six culverts area undergone settlement problem, with two boreholes were executed at the side of each culvert. Throughout the five-year period of Post Construction stage with Polygeo rehabilitation works, the pipe culvert was shown to settle around 22 mm whilst the box culvert with pile settled around 14 mm. The study concluded that the rehabilitation works using Polygeo foam has been successfully reduced the rate of settlement and complied to JKR settlement criteria

Utilization of kenaf core fiber – marine clay mixture as a landfill liner material

Nowadays, leachate production is a big concern and causes a serious hazard to the soil and groundwater which causes the subsurface soil to be polluted as a result of the loss of soil quality and environmental pollution. This study aims to study the potential of using kenaf core fiber and marine clay mixtures as improved landfill liner material. Relevant laboratory tests such as atterberg limit test, specific gravity test, and particle size distribution were performed to examine basic geotechnical properties of marine clay soil collected from Batu Kawan, Penang. Besides that, compaction test and hydraulic conductivity test were carried out for soil mixed with kenaf core fiber to determine the strength and permeability characteristics. The results found that the marine clay has significantly adequate physical properties to be used as a landfill liner. The permeability test for marine clay soil inclusion of kenaf core fibre indicated that the hydraulic conductivity of the samples admixture for 0%, 4%, 8%, and 12% ranged between 6.68 × 10-9 and 1.57 × 10-8 m/s. Compaction of marine clay mix kenaf core fibre samples resulted in maximum dry density, ρdmax that ranged between 0.936 and 1.595 g/cm3 and optimum moisture content, wopt that ranged between 19.8% and 24%. Hence the inclusion of kenaf core fiber in marine clay soil improves the maximum dry density value, decrease permeability of marine clay and could be potentially used for landfill liner material

Climatic Influence on Slope Failure: A Case Study at Kem Terendak, Melaka

Slope failure or landslide is always ascribing to the slope sculptures in the hilly area. The trend of people building a structure on a hilly area has resulted in slope cutting works being carried out aggressively and, at the same time, has increased the risk of landslides. Most of the community lacks understanding regarding slope care and maintenance, which adds to the slope suffering. One of the factors contributing to slope failure is rainfall. The rainfall-runoff to the slope erodes the turfed and topsoil particles from the slope surface. When the slope surface is exposing to extreme weather, then the slope failure will occur. These failures pose a significant engineering hazard, necessitating urgent repair work and planning in many areas. All failures that occur will require expensive repairing costs. Therefore, this study is carried out to model the rainfall-induced slope failure occurrence at Kem Terendak, Melaka. This study utilises a simulation of slope stability analysis by limit equilibrium, Slope/W 2012 and finite element software for simulating groundwater flow in saturated steady-state situations, Seep/W 2012 in order to analyse the stability of the slope with the influence of climate. Through those analysis, one can understand the causes and mechanisms of the landslide. At the same time, the factors that influence the occurrence of failures can be identified and appropriate action can be taken to reduce or even eliminate the root cause of slope failures. In addition, effective and efficient slope repair methods can be proposed with optimal cost

The Significant Effect of Interface Shear Strength Between Soil Liner and Geotextile with Different Percentages of Bentonite and Sodium Bentonite with Geosynthetic

This research focuses on the interface shear performance between geotextile and soil with various percentages of bentonite and sodium bentonite for landfill stability by using Direct Shear Test. Admixtures are mixed with clay to improve its performance as a liner material due to their ability to fill the voids between soil particles and also the most effective sealants. The aim of this study is focused on evaluating the effectiveness of bentonite and sodium bentonite on improving interface shear strength of fine soil. In this study, direct shear box was used to measure the interface shear strength of soil with different percentages of bentonite and sodium bentonite at optimum moisture content. Analysis shows that the most suitable percentage is of 5 % of bentonite and 2.5 % of sodium bentonite due to the highest interface shear strength of the mixture with geosynthetic. It is clearly shown that 2.5 % sodium bentonite is the most suitable percentage to be used as admixture for landfill stability as it gives higher interface shear strength

The Significant Effect of Interface Shear Strength Between Soil Liner and Geotextile with Different Percentages of Bentonite and Sodium Bentonite with Geosynthetic

This research focuses on the interface shear performance between geotextile and soil with various percentages of bentonite and sodium bentonite for landfill stability by using Direct Shear Test. Admixtures are mixed with clay to improve its performance as a liner material due to their ability to fill the voids between soil particles and also the most effective sealants. The aim of this study is focused on evaluating the effectiveness of bentonite and sodium bentonite on improving interface shear strength of fine soil. In this study, direct shear box was used to measure the interface shear strength of soil with different percentages of bentonite and sodium bentonite at optimum moisture content. Analysis shows that the most suitable percentage is of 5 % of bentonite and 2.5 % of sodium bentonite due to the highest interface shear strength of the mixture with geosynthetic. It is clearly shown that 2.5 % sodium bentonite is the most suitable percentage to be used as admixture for landfill stability as it gives higher interface shear strength

Performance comparison between polyurethane foam and cement grouting slab replacement for soft ground improvement at shallow depth using finite element model

Two methods of ground improvement have been proposed to overcome excessive and differential settlement problem of soft ground foundation for infrastructure such as road, highway and parking space namely polyurethane (PU) foam and cement grouting slab. It has been executed by excavating and replacing the soft soil at shallow depth with the proposed ground improvement methods. The ground improvement methods able to minimise the excessive and differential settlement as the shallow depth of soft soil is removed and replaced by the stiff materials, thus the load can be distributed evenly to the underlying soil. The comparison of performance between both methods are evaluated in this study by carried out finite element analysis for soft ground problem namely PLAXIS. The results show that the settlement can be reduced significantly to the tolerable amount by applying PU foam instead of cement grouting slab as the increase in thickness of cement grouting slab cause the increase in settlement. On the other hand, the increase in PU foam thickness has not contributed to further settlement as the PU foam is lightweight, however, the soil may experience upward displacement due to insufficient overburden load to counter uplift