Read more about the article Stabilising Technology (Tensar Tw1) Introduced to South Africa
STABILISING TECHNOLOGY (TENSAR TW1) INTRODUCED TO SOUTH AFRICA

Stabilising Technology (Tensar Tw1) Introduced to South Africa

Article discusses the use of an innovative Mechanically Stabilised Earth (MSE) wall system on the Balito Drive Road upgrade project in Durban, KwaZulu-Natal. This was one of the first and largest applications of this technology in South Africa to date. The system comprises the specifically designed TW1 block, combined with high-density polyethylene (HDPE) grid mats – known as Tensar uniaxial georgics – that are attached by a special connector into the blocks and extended horizontally to secure and reinforce the fill, thereby turning the whole structure into a monolithic mass.

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Read more about the article N2 Upgrade – Taming the Umdloti
N2 UPGRADE – TAMING THE UMDLOTI

N2 Upgrade – Taming the Umdloti

The first phase of the upgrade of the N2 Freeway Section 26 saw extensive geotechnical works. A feature of this phase of the project included the widening of the dual uMdloti River viaducts. The viaducts are founded on 45m deep piles that required subcontractor KellerFranki to import a massive Bauer BG28 rig for the project. The project also included over 2km of fabric reinforced Mechanically Stabilised Earth Walls and 2km of cut retaining walls. This article discusses some of the more interesting facets of the geotechnical components of the project.

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Read more about the article On the Influence of Varying Aperture On Flow Mechanisms In An Initially Dry Vertical Smooth Parallel Fracture Under Free-Draining Conditions
ON THE INFLUENCE OF VARYING APERTURE ON FLOW MECHANISMS IN AN INITIALLY DRY VERTICAL SMOOTH PARALLEL FRACTURE UNDER FREE-DRAINING CONDITIONS

On the Influence of Varying Aperture On Flow Mechanisms In An Initially Dry Vertical Smooth Parallel Fracture Under Free-Draining Conditions

It is essential to understand the properties and behaviour of rock mass, mainly in a hydrogeological context as well as various geotechnical applications. However, most of these processes occur as bulk fluid flow in the unsaturated zone and single fracture flow becomes imperative in understanding these processes, including, the identification of fluid flow mechanisms. The research presented in this paper investigates the influence of aperture, in a single smooth parallel plate model, on flow mechanisms under conditions of variable saturation. Visual experiments illustrate that liquid migration and to a lesser extent flow structures, are affected by varying the fracture aperture.

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Read more about the article Can One Use the Dynamic Cone Penetrometer To Predict The Allowable Bearing Pressure?
CAN ONE USE THE DYNAMIC CONE PENETROMETER TO PREDICT THE ALLOWABLE BEARING PRESSURE?

Can One Use the Dynamic Cone Penetrometer To Predict The Allowable Bearing Pressure?

It is a common question asked by the structural engineer to the geotechnical engineer whether one can determine allowable bearing pressure from a set of Dynamic Cone Penetrometer (DCP) results. This often comes as a shock to the geotechnical engineer as the DCP test wouldn’t be applicable in most applications. The DCP was originally designed in South Africa by Kleyn (1975) and was originally intended to be used for pavement applications as an indicator test.

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Read more about the article Achieving Improvement with Dynamic Replacement Stone Columns – Impact Crater Depth -Capacity Evaluation
ACHIEVING IMPROVEMENT WITH DYNAMIC REPLACEMENT STONE COLUMNS – IMPACT CRATER DEPTH -CAPACITY EVALUATION

Achieving Improvement with Dynamic Replacement Stone Columns – Impact Crater Depth -Capacity Evaluation

Dynamic replacement penetration tests, with both the Dynamic Compaction (DC) and Rapid Impact Compaction (RIC) methods, have been carried out on three sites in South Africa on variable ground profiles. Quality assurance is normally done by means of plate load tests on selected stone columns and a limit is typically placed on the acceptable deformation modulus, for the Engineer to approve works. The results from the penetration tests are presented, with a comparison of the achieved deformation moduli.

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Read more about the article Partially to Fully Saturated Flow Through Smooth, Clean, Open Fractures: Qualitative Experimental Studies
PARTIALLY TO FULLY SATURATED FLOW THROUGH SMOOTH, CLEAN, OPEN FRACTURES: QUALITATIVE EXPERIMENTAL STUDIES

Partially to Fully Saturated Flow Through Smooth, Clean, Open Fractures: Qualitative Experimental Studies

Fractures are both rough and irregular but can be expressed by a simple model concept of two smooth parallel plates and the associated cubic law governing discharge through saturated fractures. However, in natural conditions and in the intermediate vadose zone, these assumptions are likely violated. This paper presents a qualitative experimental study investigating the cubic law under variable saturation in initially dry free-draining discrete fractures.

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Read more about the article Verifying the Ground Treatment as Proposed By The Secondary Permeability Index During Dam Foundation Grouting

Verifying the Ground Treatment as Proposed By The Secondary Permeability Index During Dam Foundation Grouting

The Secondary Permeability Index (SPI) is a permeability-based rock mass classification, which when complemented with the degree of jointing can be employed as an approximation to the ground treatment design. However, when the grout mix and success of the grout operation are known, a back-analysis can be conducted to infer the degree of jointing. The aim of this paper is to back-analyse and verify the ground treatment as proposed by the SPI from water pressure tests conducted in primary production grout boreholes, at the De Hoop Dam in South Africa.

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