We undertake projects across South Africa and Southern Africa for clients from a broad selection of industries including mining, oil & gas, transport infrastructure, building construction as well as marine, river and dam infrastructure.
PORT OF EAST LONDON
This marine infrastructure project, undertaken for TRANSNET commenced in June 2015 and was completed in January 2018. The project scope included:
- Removing an existing 101m long capping beam,
- Excavating 5 870m3 to lower platform,
- Installing fifty 165mm diameter micro piles, seventeen metre deep to protect the platform, as the existing dead-man anchors were rusted through,
- Installing thirty one-metre diameter tubular piles (totally 299,5 ton), vibrated fifteen metres below the existing platform, whereafter the tubes were hammered down into the rock platform,
- Coring a two-metre rock socket in 65MPa rock,
- Vibrating sheet piles to the same level: 141 ton of sheet piles,
- Filling between an old and new wall: 527m3 concrete and 586m3 stone,
- Constructing a new capping beam,
- Pumping 689m3 compaction grouting into the platform through 106 percussion drilled holes to a depth of fifteen metres each,
- Installing ??? 572kN permanent anchors (between 25 and 30 metres) through the newly constructed capping beam, and
- Ancillary works including fenders, bollards, wooden fenders, services and paving.
This thirteen week programme saw Terra Strata install one-hundred-and-two 600mm diameter soldier piles with 582m2 of gunite archers for lateral support. The structural piles, ranging from 450mm to 900mm diameter were drilled to an average depth of eleven metres. The project scope also included 20 000m3 of bulk earthworks excavation.
This fifteen week lateral support project undertaken for WBHO/Menlyn Maine included 450 00m3 of bulk earthworks; 8 000 metres of drilling soil nails to a depth of 14m; the installation of 2 690m2 of permanent lateral support walls; and 81 structural piles, ranging from 750mm to 10 150mm diameter. It was necessary to core through 270MPa rock to form the required sockets.
92 RIVONIA ROAD, SANDTON
Terra Strata undertook the lateral support and piling to the basement at 92 Rivonia Road in Sandton, Gauteng. The lateral support consisted of soldier piles, tensioned ground anchors and shotcrete/mesh arches. In total 132 auger piles, for pile loads not exceeding 15 000kN, were cast in-situ and range between 1 050mm to 1 500mm in diameter.
TIME SQUARE, MENLYN
Terra Strata completed Phase 1 and 2 of a lateral support project for Sun International’s Time Square in Menlyn. The scopes of work included bulk excavations; drilling and installing soil nails; and guniting.
PENGE RIVER BRIDGE
Terra Strata cast a total of fourty-four 457mm diameter percussion piles up to a depth of 38 metres at the Penge River Bridge in the Limpopo Province.
EASTGATE MALL – UNDERPINNING
The underpinning works to the Eastgate shopping mall redevelopment project included the excavation of two access pits, each eight metres deep, in order to gain access to the area underneath the shopping centre. A total of 27 000m3 of material was excavated in an area with limited headroom (between 1,4 to 1,8 metres) by means of a remote controlled skidsteer, and a total of 74 pre-cast piles of 300kN each were jacked using an electronic jacking system.
Terra Strata undertook the lateral support to existing culverts on the R36 that runs between Port Alfred and East London for Murray and Roberts. The project entailed the installation combination of soil nails and self drilling anchors. Quantities included 483 nails and self drilling anchors, which equaled 2 964 metres of drilling, and a total of 1 200m2 of gunite sprayed.
SUMMIT PLACE BUILDING G, MENLYN
Terra Strata undertook the piling & lateral support to Summit Place Building G in Menlyn including:
- Drilling 72 soldier and structural piles (750mm diameter) up to 23 metres deep;
- The installation of lateral support comprising of a total of seventy-five 450kN and thirteen 600kN anchors, and 708m2 of 100mm thick gunite.
- Drilling and installing 82 structural piles ranging between 750 to 1 200mm diameter, to a depth of up to eleven metres.
105 WEST STREET, SANDTON
Terra Strata completed the lateral support to the basement at 105 West Street for client Nedbank. The scope of work consisted of soldier piles (some load bearing), tensioned ground anchors and shotcrete/mesh arches.
MASEVE SOUTH PORTAL
Terra Stratra undertook the lateral suppport to the Maseve South Portal near Rustenburg in the North West Province. The application of shotcrete to the top of the portal entrance slopes was undertaken from a telehandler.
140 WEST STREET
Terra Strata undertook bulk excavation and lateral support to a twenty-one metre deep basement for client Zenprop. The scope included 114 000m3 of bulk excavation as well as the istallation of soldier piles, gunite arches and anchors.
Terra Strata undertook the piling to three bridges for a road upgrade in Mthatha in the Eastern Cape. The project included the installation of twelve 900mm diameter piles and thirty-seven 750mm diameter piles. All piles were temporary-cased and some raked. The rock sockets were formed by coring into 30 to 100MPa hard rock.
The Sandton Skye excavation entailed the removal of 43 000m3 of material, to a depth of 11 metres and the installation of 1 760m2 of permanent lateral support, made up of soldier piles, anchors and soil nails.
MALL OF AFRICA – LATERAL SUPPORT WALL
Terra Strata constructed the Mall of Africa’s 13.5 metre high lateral support wall with its 70 soldier piles and 140 anchors, ranging between 450 and 600kN.
PILING TO BRIDGE – N4 HIGHWAY
Terra Strata cast 39 temporary in-situ piles at this bridge over the N4 highway, some of which were raked 1:6 – 13 metres deep.
LATERAL SUPPORT FOR MINE BOX CUT
Terra Strata undertook the lateral support for a Limpopo-based platinum mine’s box cut, entailing:
Drilling for lateral support, including:
- Drilling and installation of soil nails of various lengths:
- 3m x 1733No for a total of 5 199m.
- 6m x 491No for a total of 2 946m.
- 9m x 3No for a total of 27m.
- Drilling and installation of two-metre resin bolts, 486No for a total of 972m.
- Drilling and installation of two-metre Splitsets,168No for a total of 336m.
- Drilling and installation of Cable-lock anchors 33No for a total length of 295m.
- Total metres of installation support equates to 9 775m on 2 914 positions.
Meshing and wetcreting for lateral support, including:
- Installation of 6 732m2 of 50x50x4 diamond mesh.
- 2 347m2 and 340m3 of 25MPa wetcrete application with an average thickness of 150mm.
- SDA’s (spiles) are planned for the hitch area of the box cut.
- Total SDA’s planned: 264No, eight metre deep with one metre protrusion using R38N. This equates to 2 112m of drilling and 13 140 litres of grout.
ENVIRONMENTAL: DEEP GROUNDWATER SEEPAGE CONTROL DRAINS AND BARRIERS
Terra Strata completed the construction of deep groundwater seepage control drains and barriers for a speciality chemicals company in Newcastle comprising:
- Line C: Construction of a 233 metre long, ten to 13.5 metres deep cut-off drain:
- The drain was constructed by drilling a series of secant 1050mm diameter piles, backfilled with alternating concrete and drainage material (filter sand) to form a continuous drain.
- The sand filled piles were lined with a geotextile sock which ranged between ten to 13.5 metres deep.
- Extraction wells were installed in various sections along the line comprising a geotextile lined, 19mm stone filled hole with a central perforated pipe.
- Line D: Construction of a 160 metre long by four- to eleven metres deep cut-off barrier and drain:
- The cut-off barrier was constructed by installing a continuous row of sheet piles to refusal depth up to 11.5 metres.
- A 4.5 metre deep geotextile lined drain was installed in front of the sheet pile barrier and filled with drainage material (19mm stone).
- Perforated extraction points were installed along the drainage line.