Shallow pad, strip and raft footings.
On project sites with good near surface ground strata concentrated structural loads, such as below columns, tower cores or load bearing walls, can generally be supported on shallow foundations. The shallow foundations, in the form of discreet pad, continuous strip footings and rafts, are required to resist the applied loads by transferring increased stress into the shallow founding strata at levels that maintain acceptable total and differential settlements.
Shallow footings generally take the form of cast insitu or pre-cast concrete pad, strip or raft elements constructed with a foundation depth between 0.6m to 2.0m below the ground surface. Where the shallow founding ground strata has adequate strength and stiffness, and is not subject to significant surface movement due to seasonal changes in moisture content, shallow foundations generally provide the most cost effective solution.
Factors including the nature of the near surface and deeper ground strata, ground water levels, loads to be carried, settlement tolerances and design life combine to dictate the optimum shallow foundation type for any project. Where raft foundations are selected detailed 3D soil structure analysis is required to assess likely settlements and to determine the magnitude of stresses and bending moments induced in the raft slab. The CMW design team have experience and dedicated 3D finite element software to facilitate efficient analysis and design of raft foundation solutions.
The CMW design team has extensive experience in analysis, design and specification for shallow foundations. Our experience, frequently gained through working on foundation solutions associated with our geotechnical investigations, enables us help select the optimum foundation type for routine, low risk and problematical sites.