Stay informed. For the latest information from HHO, please visit

Geotechnical Investigations

At HHO, we understand the need to develop infrastructure that benefits humankind. Most of what we see around us, whether it be the humblest of dwelling to the largest dam, is either supported by soil or rock. Geotechnical investigation involves methods of exploring and testing to determine the subsurface conditions and material properties that facilitate the engineering design of such structures.

Our geotechnical investigation division is highly experienced in the diverse exploratory methods and laboratory analyses of soils and rock available, and we are able to tailor the scope and methods of investigation to best suit the development proposed and the level of information desired. This, together with our geotechnical staffs' extensive experience, ensures the highest level of detail and value for money from investigations undertaken. Among the services our geotechnical investigation division can offer are:

  • Planning and execution of subsurface investigations for new residences or home additions in accordance with SANS 10400
  • Planning, execution and reporting on Preliminary, Phase 1 and Phase 2 detailed geotechnical investigations for township and/or housing developments in accordance with SANS 634 specifications
  • Detailed soil profiling, percussion and rotary core borehole logging in accordance with SAICE’s Guidelines for Soil and Rock Logging in SA
  • Planning, specification, procurement, contract administration and reporting on geotechnical investigations and testing for design of infrastructure ranging from roads to bridges, lateral support and retaining walls to multi-storey buildings including specialist structures such as reservoirs and wind turbines.

Borrow Pit Investigations, Free State, South Africa

As part of the upgrades to the R34 and N1, HHO undertook geotechnical investigations for suitable sources of gravels and crushed stone for road construction activities. Desk studies, field reconnaissance, percussion and core drilling and extensive testing in line with COTO requirements were used to identify and classify suitable source of material.

Geotechnical Investigations for M3 Upgrades, Cape Town, South Africa

HHO undertook geotechnical investigations for the upgrading of the M3 motorway in Cape Town. The subsurface investigations involved test pitting, in-situ testing, rotary core drilling and geotechnical laboratory testing to assess earthworks and founding conditions for road widening and associated infrastructure.

Geotechnical Investigations for Redevelopment of Strand Street Quarry, Cape Town, South Africa

HHO undertook a slope stability assessment of the existing sidewalls of an historic quarry site in Cape Town as part of the planning to redevelop the site for the City of Cape Town. Detailed joint surveys, geological mapping, kinematic analyses and stereographic interpretations were used to identify potentially unstable rock faces and define rock fall risk and propose mitigation measures for safe redevelopment.