The construction trade has a certain reputation for being a harsh environment in which brute force takes precedence over calculated thought; however this impression is far from appropriate. There is a substantial amount of work that happens behind the scenes of the demolition and construction industry that is firmly grounded in the academic arena. Furthermore, this unseen work is vital to the success of the more visible operations.

One branch of this unnoticed work is site surveying, or more precisely pre-demolition and post-demolition topographical surveying. This sort of work demands a great balance of specific technical knowledge as well as experience of the industry and a genuine intuition for the intricacies of the job. This article explores the ins and outs of this work.

Topographical Surveys

A topographical survey is a report of the actual features of a given plot of land. The aim of a topographical survey is to map the naturally occurring and man-made features of a particular landscape to a high degree of accuracy.

Topographical surveys could be carried out on a very broad range of environments, from open countryside to urban areas and across a variety of elevations and land surfaces. Surveys can be developed to take into account a great number of factors, such as ground conditions or vegetation, and as such can be used for a number of tasks. A few of the more common uses are outlined below.

Common Applications for Topographical Surveys

Probably the most extensively used, and most generally recognised application for topographical surveys is cartography, or map making. Modern maps include a great amount of information about the terrain they relate to, including waterways, reliefs and ground surface, all of which will have been obtained via a topographical survey.

Topographical surveys also have a key role to play in the construction business. When people or companies are looking to build any kind of structure they will need to carry out extensive surveys as part of the design phase of the project.

Surveys also play a key safety part in primary industries like mining, or in other industries that interact with the terrain, such as demolition and infrastructure. Organisations in these industries will use surveys to plan their projects, but also to make sure that they can guarantee the safety of their workforce on site.

Engineers as well as building staff use building demolition surveys for detailed sizes of internal and exterior structures.

Types of Survey

The world of topography covers a large number of physical characteristics so it is important to identify what form of topographical survey is suitable for a particular situation. A few of the more common types of survey required for construction sites are discussed below.

“Lie of the land” Surveys

These types of topographical surveys are designed to create an overview of the physical properties of any given plot of land. Although the information gathered by the survey will be extremely accurate, and can be very extensive, the objective of these surveys is to give a site summary.

These surveys will usually incorporate a boundary survey that sets out to define the extent of the site and spotlight any specific restraints that are determined by the geography of the site. They may also include a level survey that will plot the elevation of the terrain and the various gradients that exist.

Building Surveys

Building surveys are more generally concerned with man-made structures on a site, including the surveying of special machines and even infrastructure features. This type of survey is more commonly associated with the demolition sector because it can give a detailed plan of the structure to be demolished. It may be used for other projects as well.

A building survey will probably include a measured survey, which involves creating a comprehensive plan of the exterior and internal dimensions of a structure. Depending on the requirements of the job, a measured survey could provide simple building “footprint” dimensions, or might produce a very detailed plan of the structure.

Content of a Topographical Site Survey

A survey of a demolition site will almost definitely include the details gathered by the types of boundary and building surveys described above. This information will be necessary so that the demolition firm can plan a demolition that is both adequate and secure. Often these surveys will also be legally required.

Surveys will often contain information about the utility services that are present on a site before any demolition or construction work takes place. This is an important safety factor since any unmonitored damage to pipes and cables carrying water, gas and electricity might be very dangerous.

Another aspect of the site study will often be an inventory of materials on the site. This type of study will be a quantity survey of the various sorts of materials that can be found on site, for example, tiles and masonry, concrete that can be used as hardcore or even timber. By getting an accurate audit of site materials the construction firm can more precisely determine the need to import building resources, or they can re-use the materials on a different project.

Topographical surveys and resource quantity reviews make up a single branch of demolition services provided by contemporary organisations that conform with business best practices.

Importance of Site Surveys

Perhaps the most significant reason to perform a topographical site survey is to ensure the safety of the people who will be doing work on the site. The industrial sectors that most commonly call for site surveys are risky enough as it is without having to be concerned about the condition of the ground on which they are working. Taking a detailed topographical survey can help to mitigate safety risks of this nature.

Another important reason to get a proper survey done is to identify any potential difficulties that may arise because of the physical properties of the area. Particular things will not be evident on the surface of the site and will only be uncovered once digging or demolition has begun. By then it may be too late to fix these problems, or at best they will be expensive problems to solve.

The inventory of site supplies, as previously mentioned, can be of great benefit to a demolition or construction organisation working on a project. Not only are building materials themselves costly, but importing them to the site could be a very expensive task in itself. Any time that material can be recycled on site offers an opportunity to save development time and money. Only by taking an exact audit of these supplies can a company correctly plan its imported material needs.

Topographical surveys can also highlight other areas that will be of use to the project managers. For example, if the gradients on a site would be prohibitive to particular vehicles or equipment then a new entry route or alternative machinery will have to be found.

Positioning of Survey Control

During the surveying and construction stages of a building project, the equipment required for the physical surveying of the site and control of the survey data will often be kept on-site. This is obviously a problem when it comes to the demolition phase of a project since the machinery is both costly and sensitive.

Once the demolition has taken place and the site has been deemed safe for personnel to return to it, the surveying equipment can be restored to its original position on site. This will allow for efficient data collecting to take place for a post-demolition survey, and retains a single point of contact for anybody who needs the topographical survey information.

One of the most specialist areas of industrial demolition regards the disposal of dangerous substances that may be damaging to the natural environment.

Who can Perform Site Surveys?

Because topographical site surveys can play such a critical role in the success or failure of a construction or demolition project it is critical that they are undertaken carefully by the correct people. There are different branches of site surveying and each one will have specific qualifications associated with it.

When choosing a company to undertake the surveying work required for your project it will be wise to choose a business with a good reputation and a proven track record. Ask to see examples of their previous work and try to get feedback about their overall performance on previous projects.

Who will use the Survey Information?

When an adequate level of details has been gathered by a site survey it must be passed out to the appropriate personnel on-site. Who gets which pieces of information will mostly depend on the job roles being executed, but can also rely on the stage that a project is at. There will be much less need for materials information half way through construction for example.

Project Planners

Project planners will usually require access to all of the information collected by a topographical survey, though they will particularly need to use information concerning the physical relief of a site before the design phase, and a site materials record before they can prepare the construction phase. The more information that can be made available to project planners will help the smooth running of the project.

Demolition Experts

Demolition organisations will want to know about the interior and external characteristics of any building or structures that they are arranged to take down. Whilst every job will have different requirements, demolition workers will generally need to know about the fundamental framework of a building and the materials it is made out of. They will need this information before demolition can take place.

Site Engineers

Construction engineers on-site will be particularly interested in the survey information about the relief and topography of the terrain. It is normally the case that they will need to build on a flat surface, so they will use details about the natural lay of the land to calculate what work will be required to create a steady footing for any building.