The early adoption of a ground investigation contractor can have a positive impact on the cost of a project by influencing every phase – concept, planning, design and construction.
In planning, for example, this can involve providing even the most basic data typically seen in a ground investigation report, such as the nature of the existing site, surface conditions, access, depth and location of geotechnical and environmental hazards.
From an investment viewpoint, additional or emergency engineering solutions and subsequent remedial measures can often exceed the value of the ground investigation contract. This can impact significantly on a client's return on outlay and project programme.
It reinforces the view that ground investigation is linked directly to risk management (cost and programme certainty) and economic and appropriate design (cost minimisation). Yet it remains a relatively low-cost service, sometimes saving millions of pounds, often for a fraction of 1% of the total construction cost.
However, not all clients recognise the benefits of good ground investigation, taking the view that the project's risk is not great enough to warrant additional cost. This can lead to decisions based on data that is incomplete , for example, where it is withheld for contractual reasons, or inadequate because of inappropriate techniques or poor soil sampling.
Appropriate data is king and only relevant experience, expertise and resources can deliver a complete and suitable geotechnical report. As far as its usefulness is concerned – a rule of thumb – value for money does not always mean low price procurement.
It does mean, however, a good desk study, good site scoping, accurate data, defined reports, decent borehole location plans, a good mix of in-situ and laboratory test data and perhaps, most importantly, targeted information that is specific to the structure's location.
From an interpretative reporting point of view it can also lead to more realistic budgeting, for example, on decisions about existing pile and foundation integrity and whether new ones are needed. It is important to understand the impact older foundations have on modern geotechnical design.
Existing foundations may perform satisfactorily under new loads, even though they are decades old. However, they may not satisfy regulations. The ground may also be too congested. These questions need accurate answers and are why appropriately designed and targeted ground investigation is a good investment in time, money and resources for the client.
The early addition of an experienced and well resourced ground investigation contractor to the team often means the most suitable techniques and instrumentation are used.
This is paramount to shortening the ground investigation project time. Projects can be planned to operate at optimum efficiency, particularly where costly construction delays are attributable to difficult ground conditions or access.~
After all, geotechnical engineers working at the coalface are best placed to understand what works best and what does not. Also they are often closely linked to research and development of newer and better applications, which can ultimately lead to efficiency gains.
The bottom line is early involvement of ground investigation is intrinsic to the financial good of the whole project. This thinking would see ground investigation as a valuable way to deliver construction projects on time and on budget.