How Geotechnical Services Reduce Construction Risk and Cost Overruns

Construction can be an expensive game, but what if there was a way to save a lot of money before you even start? Builders mainly focus on what is above ground. Meanwhile the important information that can bring project costs down are underground.

A geotechnical survey looks at what is underground beneath your project site. It can inform you of the best foundations to lay so your project above ground is solid and safe. Understanding the ground beneath your feet can literally save you millions of dollars.

In this article we’ll explain what is involved with a geotechnical survey, why your project needs one before construction begins and how it can reduce costs for your project.

What is a Geotechnical Survey?

A geotechnical investigation, or survey, is an exhaustive investigation and thorough report on a site’s soil, rock, and groundwater properties. This helps to assess if the ground can support planned construction.

The comprehensive report we produce identifies potential issues that could impact your building, such as high water tables and the risk of seepage, or instability under the ground. It can also identify where there is solid ground for better strength to support buildings.

It shows how much weight a soil area can bear. What the compressibility of soil is, its strength and ability to be stable under varying conditions.

This report is a guide, a map, helping engineers navigate the complex nature of the surface soil and what lies beneath. Knowing all of this information allows for smart decisions to be made now, rather than having to fix costly problems later. It can give you confidence knowing you’re building somewhere safe, and building something that will last a long time.

There are a few different kinds of tests we can do in a geotechnical survey.

• Standard Penetration Test – This test determines how dense the soil is. It helps determine certain soil parameters such as the angle of shearing resistance and the shear strength of cohesive soils. A sampler is hammered into the ground via a borehole. It gains an N count or SPT blows per 300mm, and then it is withdrawn with soil samples for testing. This N count is used to correlate density, consistency and strength of the soil.

• Specialised and Dynamic Penetration Test – These tests also correlate density, consistency and strength of the soil and are normally used for assessment of soils close to the surface particularly pavements and structures having shallow foundations.. These tests can be used to verify bearing capacity.. A very comprehensive series of tests each with their own specialised set of tools.

Why do I need a Geotechnical Survey?

There are many good reasons you need a comprehensive geotechnical report from Site Geotechnical.

• Safety and Stability. Arguably the most important reason is for safety. You want reassurance that what you build won’t collapse and injure people, that it won’t slide down a hill and endanger other people and property as well. The more stable the ground, the more settled a building will be and the safer everyone involved, from the workers on construction to the people who occupy the building upon completion.
• Cost-Saving Design. The data helps dictate the foundations of a building or road or anything built on the ground. Ignorance of the groundwork can lead to over-engineering to be safe, which can cost a lot of unnecessary dollars. Knowing what to build now can also save major redesigns later.
• Compliance. A ground survey is often required by local councils and building codes for eligibility for permits but most importantly provides guidance as to what is needed
• Risk Mitigation. Knowing all the information you can about the subsurface limits the risks involved in construction. Understanding liquefaction risks or hidden subterranean voids now, before discovering them once work is done, is good planning.
• Environmental Assessment. A geotechnical survey can assess risks to groundwater pollution, or if there is any other contamination in the soil beneath your construction site.
• Helps Plan Construction. Knowing what the ground is composed of means you can use the right equipment and the correct methods of digging foundations without any delays, reducing any potential budget blowouts, and saving money.

How a Geotechnical Survey will Reduce Risks and Costs

You’ve read what a geotechnical survey is and why you need one. We’re now going to extrapolate from that and show you how it will reduce risks on your building site and reduce the costs of your project both potentially and actually.

Foundation Certainty.

Knowing with certainty what lurks in the ground allows engineers to design the most suitable and cost-effective foundation system for your project. The choice can be made between shallow footings versus digging and installing deep pile foundations.

This knowledge prevents under-design that can lead to building failure, and over-design which wastes valuable time and materials.

Accurate Cost Estimation

Eliminating guesswork and estimation through geotechnical reports and soil/rock summaries leads to more accurate budgeting and costs. You are more able to accurately budget for manpower, time and materials.

This accuracy can also give you a stronger case for securing finance for our project. It can also reduce the likelihood of needing emergency funds at a later date.

Efficient Use of Materials.

Builders can use the right materials for the right job, first time. More accurate orders of materials can be made as well, eliminating overheads and wastage.

For example, knowing the soil composition leads to correct drilling for foundations, which leads to knowing just how much concrete is required for the foundations, reducing wasted concrete from the pour.

Reducing Long-Term Maintenance

Buildings which rest on solid and stable foundations, thanks to stable ground beneath them, have fewer issues such as uneven settlement or structural deterioration over time. This can save a lot of money on structural maintenance down the years.

Informed Planning

The more information you have about a subject the better you can make decisions. Having a Geotechnical survey can help you plan future developments on the same property.

Further projects on site can be planned with efficiency, saving time and money. It can also lead to ideas and expansions you may not have thought of, such as excavations where you thought it may not be possible with the bedrock.

Why choose SITE Geotechnical for Your Survey?

A good quality geotechnical survey will give you extensive knowledge to make key decisions for your project that will save you time and money and heartache. We offer comprehensive and accurate geotechnical services for the greater Melbourne area, and rural locations such as Gippsland and Melton. Our team brings over twenty years of success with us to every job.

You can give our team a call on 1300 557 260 or drop us an email with our online contact form and we can discuss your future projects and how our team can work hand in hand with yours.