The demolition industry has a particular reputation for being a harsh environment in which brute force takes precedence over calculated thought; however this image is far from correct. There is a substantial amount of work that happens behind the scenes of the demolition and construction sector that is firmly rooted in the academic world.
One branch of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This sort of work calls for a good balance of specific technical know-how as well as experience of the industry and a natural intuition for the intricacies of the job.
Topographical Surveys
A topographical survey is a report of the actual features of a particular plot of land. The purpose of a topographical survey is to chart the naturally occurring and man-made traits of a specific landscape to a high degree of precision. Whilst topography itself can refer to the surface of any kind of object, it is more commonly associated with the surface of the planet.
Topographical surveys can be carried out on a very broad range of landscapes, from open countryside to urban developments and across a variety of elevations and land surfaces. Surveys can be designed to take into account a great many factors, such as ground variables or vegetation, and as such can be used for a multitude of tasks.
Common Applications for Topographical Surveys
Perhaps the most widely used, and most generally recognised application for topographical surveys is cartography, or map making. Modern maps include a great deal of detail about the terrain they relate to, including waterways, elevations and ground surface, all of which will have been collected via a topographical survey. This information is also being made available online.
Topographical surveys also have a major role to play in the construction industry. When people or companies are looking to build any kind of structure they will need to undertake extensive surveys as part of the design phase of the project. These surveys are often an important part of any application for planning permission as well.
Surveys definitely play a key safety part in primary industries like mining, or in other industries that interact with the land, such as demolition and infrastructure. Companies in these fields will use surveys to prepare their projects, but also to make sure that they can guarantee the safety of their workforce on site.
General topographical surveys are concerned with physical characteristics of land though building demolition surveys focus on man made buildings which have been marked for destruction.
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 scenario. A few of the more typical types of survey required for construction sites are reviewed below.
“Lie of the land” Surveys
These types of topographical surveys are fashioned to create a summary of the physical characteristics of any given plot of land. Whilst the data collected by the survey will be very 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 determine 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 numerous gradients that exist. Any survey can be customised to specification though.
Building Surveys
Building surveys are more typically concerned with man-made constructions on a site, including the surveying of special apparatus and even infrastructure characteristics. This type of survey is more regularly associated with the demolition industry because it can give a detailed plan of the building to be demolished.
A building survey will almost certainly include a measured survey, which involves creating a comprehensive plan of the external and interior dimensions of a structure. Depending on the requirements of the job, a measured survey might provide simple building “footprint” dimensions, or might produce a highly detailed plan of the structure.
Content of a Topographical Site Survey
A survey of a demolition site will almost definitely include the information gathered by the types of boundary and building surveys described above. This information will be required so the demolition firm can plan a demolition that is both satisfactory and safe. More often than not these surveys will also be legally required.
Surveys will often include information about the power services that are present on a site prior to any demolition or construction work happens. This is an essential safety aspect since any unmonitored damage to pipes and cables carrying water, gas and electricity might be very dangerous.
Another aspect of the site survey will often be an audit of resources on the site. This type of study will be a quantity survey of the various types of materials that can be located on site, for example, tiles and masonry, concrete that can be utilised as hardcore or even wood. By taking 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 job. These surveys can be made pre-demolition and post-demolition.
Nearly all building projects require topographical demolition surveys since legislation and health and safety have become critical requirements.
Importance of Site Surveys
Maybe the most significant reason to undertake a topographical site survey is to ensure the health and safety of the individuals who will be doing work on the site. The industrial sectors that most frequently call for site surveys are dangerous enough as it is without having to worry about the integrity of the ground on which they are working. Taking a comprehensive 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 problems that may arise because of the physical characteristics of the region. Particular things may not be evident on the surface of the site and will only be uncovered once digging or demolition has started. By then it may be too late to fix these problems, or at best they will be expensive issues to solve.
The inventory of site materials, as previously mentioned, can be of great value to a demolition or construction company working on a project. Not only are building materials themselves expensive, but importing them to the site may be a very expensive task in itself. Any time that material can be reused on site offers an opportunity to save development time and funds.
Topographical surveys can also identify other areas that will be of use to the project managers. For example, if the gradients on a site would be prohibitive to specific vehicles or equipment then a new access route or alternative equipment will need to be found.
Positioning of Survey Control
During the surveying and construction stages of a building project, the apparatus 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 stage of a project since the equipment is both expensive and sensitive. It is therefore wise to move this equipment off-site during demolition.
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 initial position on site. This will allow for effective data gathering to take place for a post-demolition survey, and keeps a single point of contact for anybody who needs the topographical survey information. Most surveying companies will oversee this redeployment.
One of the most specialised parts of industrial demolition concerns the removal of unsafe materials that may be damaging to the environment.
Who can Perform Site Surveys?
Since topographical site surveys can play such a critical role in the success or failure of a building or demolition venture it is vital that they are undertaken carefully by the right people. There are different branches of site surveying and each one will have unique qualifications associated with it. Finding surveyors with these specific skills will certainly be advantageous.
When selecting a company to undertake the surveying work necessary for your project it will be sensible to choose a company with a good reputation and a proven track record. Ask to see examples of their previous work and try to obtain feedback about their overall performance on previous projects.
Who will use the Survey Information?
Once an adequate level of details has been accumulated by a site survey it must be handed out to the appropriate people 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.
Project Planners
Project planners will usually need access to all of the information gathered by a topographical survey, though they will particularly need to use information regarding the physical relief of a site before the design phase, and a site materials inventory before they can prepare the construction phase. The more data that can be made available to project planners will help the smooth running of the venture.
Demolition Experts
Demolition companies will want to know about the internal and exterior characteristics of any building or structures that they are arranged to take down. Whilst every project will have different requirements, demolition experts will typically need to know about the fundamental structure of a building and the materials it is made out of.
Site Engineers
Construction engineers on-site will be particularly interested in the survey statistics about the relief and topography of the terrain. It is normally the case that they will want to build on a flat surface, so they will use details about the natural lay of the land to determine what work will be needed to create a stable footing for any structure. They will want this information prior to and during the construction stage of a job.