Personal Project Experience
Geotechnical Investigation - Zimbali Lakes
Geotechnical investigation for a new residential development in Zimbali Lakes.
Zimbali Lakes is situated on the portion of land between the M4 and N2 highway, to the west of Port Zimbali Estate, on the North Coast of KZN.
The investigation comprised carrying out Dynamic Cone Penetrometer (DCP) tests, the mechanical excavation of Inspection Pits (IP) and sampling of material for laboratory testing.
A comprehensive geotechnical report was provided to the client . The report included the interpretation of the ground conditions, site drainage, founding, material suitability, earthworks and excavatability.
SBMA Anchor Design
Due to years of corrosion, an existing Dock's sheet piled wall needed to be replaced and reinforced with ground anchors.
Project constraints included high anchor loads and weak ground conditions associated with the site. The underlying soils comprised a deep horizon of soft alluvial soils. Competent material, was only recorded at some 10m below anchor installation level. Due to the depth of the competent material and the high loads that needed to be resisted, typical bar anchors was not be a feasible option.
The most suitable solution was the incorporation of Single Bore, Multiple Anchors (SBMA). SBMA anchors, as its name suggests, allows multiple strand anchors to be installed in the same bore. The advantages of this technique is the ability to install the efficient utilization of a (theoretically) unlimited fixed anchorage length in any one borehole.
The strand’s respective load transfer lengths are located in the borehole at staggered, but controlled, positions within the total SBMA Fixed Length. This enables transfer of each unit load component, in a controlled manner, to a discrete length of the borehole thereby producing a very efficient load transfer mechanism which is far less susceptible to progressive grout/ground failure modes, associated with conventional multi-strand configurations, in weak, variable strata.
The final design comprised 5 No. 3m fixed length strands (15m of strands), with a 15m free length.
Secant Wall Design
This project required the design of a retaining solution for the construction of a three-storey basement in London.
The final design comprised of a 750mm diameter cased secant piled (CSP) wall. I was responsible for early stage collaboration with the main contractor and engineer to develop a winning secant basement retaining wall solution from successful bid to delivery. Project constraints included a high water table, limited embedment depths due to underground services and tight deflection criteria’s due to sensitive adjacent properties.
Secant Wall Design
The client required the design of a double-storey secant piled wall and the bearing piles for a proposed new multi-storey mixed-use development. Due to a high water table and the need for deep basement construction, a secant wall was the most practical choice. Groundwater was present above the proposed excavation level and therefore, the wall was required to act as a groundwater cut-off to prevent flow directly from the retained ground into the excavation.
The bearing piles and secant piled wall comprised of 600mm diameter CFA piles.
Temporary work designs for tower crane tension piles and the design of a piling platform was also delivered.
Geotechnical Site Investigation - Mandlazini Pump Stations, Richardsbay
This project involved the geotechnical investigation of twelve gravity fed pump stations for a new mixed residential and commercial development in Richardsbay.
The investigations comprised rotary core borehole drilling and inspection pits by excavator.
A comprehensive geotechnical report was provided to the client . The report included the interpretation of the ground conditions and laboratory testing as well as the preliminary design of shoring options (contiguous piled walls and timber lagging) to allow safe construction of the stations.
Site Supervision - Rickivy Pipe Jack
A large sinkhole developed on the N3 carriageway on Town Hill, between PMB and Hilton. It was soon identified that the sink hole had developed directly above an existing Armco pipe that lay approximately 10m below road surface level. The Armco pipe had corroded and collapsed, resulting in the formation of a sink hole.
Initially, I oversaw the remedial work done from the surface of the road which comprised the stabilization of the collapsed section by means of drilling probes and pressure grouting up the cavities. Thereafter, I oversaw the installation of a new storm water pipe by means of jacking a concrete pipe under the highway, encapsulating the existing damaged Armco pipe.