Standard Proctor Compactive Effort Research Articles

GEOTECHNICAL ASSESSMENT OF PALM OIL FUEL ASH (POFA) MIXED WITH GRANITE RESIDUAL SOIL FOR HYDRAULIC BARRIER PURPOSES

This paper assesses the geotechnical properties of granite residual soil treated with palm oil fuel ash (POFA), a waste from the palm oil factory for the purposes of hydraulic barrier in landfills. Granite residual soil treated with up to 40% palm oil fuel ash (by dry weight of the soil) was compacted using standard proctor compactive effort at the optimum moisture content. Index properties, hydraulic conductivity (k), volumetric shrinkage strain (VSS) and unconfined compressive strength (UCS) tests were carried out. Results showed that the index properties of samples met the minimum requirement for it to be used ass a liner. The maximum dry density and optimum moisture content decreased and increased respectively. The influence of POFA treatment on the geotechnical properties generally showed an improvement with up to 15% POFA which gave the acceptable results with regards to its usability as a hydraulic barrier material in landfill.

Comparative reliability evaluation of lateritic soils as hydraulic barriers

A numerical investigation to determine the existence or otherwise of congruence between laboratory-based and field-based models for predicting hydraulic conductivity of compacted clay liners has been conducted. The comparisons here are based on values of the reliability index estimated with the use of the two models for cases when hydraulic conductivity is assumed to be normally and lognormally distributed. The laboratory reduced Proctor and modified Proctor compactive efforts were assumed to correspond to the lowest and highest compactor weights (165 kN and 338 kN for sheepsfoot rollers only from literature) respectively. The standard Proctor compactive effort was assumed to correspond to the mean compactor weight of 261.4 kN. Reliability estimates from the laboratory-based model were consistently higher than the corresponding values from the field-based model for each of the variables common to the two models. As laboratory samples usually involve small samples which are often unrepresentative of field situations, it is considered that reliability levels estimated with the use of the field-based model provide more realistic assessment of compacted lateritic soils as hydraulic barriers. Compactor weight of 300 kN and above may be needed for effective compaction of lateritic soil liners. Reliability-based designs of lateritic soil liners should incorporate appropriate probability distribution types for variables in the field-based model.

Geotechnical characteristics of compacted clays for earth embankments in the Prairie provinces

The geotechnical characteristics of compacted soils used by the Prairie Farm Rehabilitation Administration in earth embankments were correlated with easily obtained soil properties.Relationships were established between Standard Proctor maximum density and optimum water content versus liquid limit for clay soils. In addition, a relationship was established to determine the Standard Proctor maximum dry density and optimum water content using the results from the one-point Proctor test for clay, and sand and silt soils.Effective shear strength parameters and consolidation characteristics of compacted samples were related to liquid limit, water content, and dry density. The results of field and laboratory measurements of pore pressure were used to relate the pore pressure coefficients U/σ3 and U/σ1 to the deviation of water content from optimum water content and applied stress. A relationship was established between embankment compression and embankment height using field measurements of embankment settlement.The data suggest that similar geotechnical characteristics will be obtained for laboratory and field compacted alluvial and glacial soils when they are placed with Standard Proctor compactive effort at similar water contents, densities, and liquid limit. In this paper 'alluvial clay' is used to describe clays deposited in lacustrine or fluvial environments and 'glacial clay' is used to describe clays deposited by a glacier.