The demolition industry has a particular character for being a tough environment in which brute force takes precedence over calculated thinking; however this image is far from correct. There is a huge amount of work that goes on behind the scenes of the demolition and construction sector which is firmly rooted in the academic arena.
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 good balance of specific technical knowledge as well as experience of the industry and a genuine intuition for the complexities of the job.
Topographical Surveys
A topographical survey is a report of the physical features of a particular piece of land. The aim of a topographical survey is to map the naturally occurring and man-made traits of a specific landscape to a high degree of precision.
Topographical surveys could be carried out on a very wide range of environments, from open countryside to urban areas and across a variety of reliefs and land surfaces. Surveys can be developed to take into account a great many factors, such as ground conditions or vegetation, and as such can be used for a number of tasks.
Common Applications for Topographical Surveys
Probably 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 landscape they relate to, including waterways, reliefs and ground surface, all of which will have been gathered via a topographical survey. This information is also being offered online.
Topographical surveys also have a major role to play in the construction industry. When people or companies are looking to construct any kind of structure they will need to perform extensive surveys as part of the design stage of the project. These surveys are often an essential part of any application for planning permission too.
Surveys also play a key safety role in primary industries such as mining, or in other industrial sectors that interact with the terrain, such as demolition and infrastructure. Businesses 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.
A location due for demolition work ought to go through a demolition survey regarding staff safety as well as monetary planning reasons.
Types of Survey
The world of topography covers a large number of physical characteristics so it is important to determine what form of topographical survey is appropriate 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 fashioned to create a summary of the physical properties of any given plot of land. Whilst the information collected by the survey will be very accurate, and can be very extensive, the purpose of these surveys is to provide a site summary.
These surveys will generally include 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 land and the numerous gradients that exist. A 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 machines and even infrastructure characteristics. This type of study is more commonly associated with the demolition industry 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 detailed plan of the exterior and internal proportions of a building. Depending on the requirements of the project, 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 always include the information gathered by the types of boundary and building surveys mentioned above. This information will be necessary so the demolition company can plan a demolition that is both satisfactory and safe.
Surveys will often contain information about the utility services that are present on a site before any demolition or construction work happens. This is an important safety aspect since any unmonitored damage to pipes and cables carrying water, gas and electricity could be very dangerous. The information could also be used to plan new buildings, based upon the existing supply of these ammenities.
Another aspect of the site study will often be an audit of resources on the site. This type of survey 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 timber. By taking an accurate audit of site materials the construction firm can more precisely gauge the need to import building materials, or they can re-use the materials on a different project. These surveys could be made pre-demolition and post-demolition.
Performing a thorough and complete house demolition survey ensures the protection of residents in the immediate vicinity of the work site.
Importance of Site Surveys
Possibly the most important reason to undertake a topographical site survey is to ensure the safety of the individuals who will be working on the site. The industrial sectors that most frequently call for site surveys are dangerous 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 eliminate safety risks of this nature.
Another important reason to get a suitable survey done is to identify any potential problems that may arise because of the physical characteristics of the region. Certain things will not be evident on the surface of the site and will only be discovered once digging or demolition has begun.
The inventory of site materials, as previously mentioned, can be of great benefit to a demolition or construction company working on a project. Not only are construction 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.
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 certain vehicles or equipment then a new entry route or alternative machinery will have to be found. Equally, an appropriate site will need to be found for the base of control operations for the project. Good site surveying can help out in these less tangible ways.
Positioning of Survey Control
During the surveying and construction stages of a construction 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 clearly a problem when it comes to the demolition period of a project since the machinery is both expensive 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 gathering to take place for a post-demolition study, and maintains a single point of contact for anybody who needs the topographical survey information. Most surveying companies will oversee this redeployment.
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 carried out carefully by the correct people. There are different divisions of site surveying and each one will have specific certificates associated with it. Finding surveyors with these specific qualifications will certainly be advantageous.
When choosing a company to undertake the surveying work required for your project it will be sensible to choose a company with a good reputation and a proven track record. Ask to see reviews of their previous work and try to obtain feedback about their performance on previous projects. It may also be worth thinking about how a company can deliver their survey information, i.e. in 3-D models or CAD ready formats, for ease of integration with other members of the project staff.
Who will use the Survey Information?
When 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 what pieces of information will mostly depend on the job roles being performed, but can also rely on the stage that a project is at.
Project Planners
Project planners will usually require access to all of the information gathered 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 plan the construction phase.
Demolition Experts
Demolition businesses will want to know about the internal and external characteristics of any building or structures that they are arranged to take down. Whilst every project will have different requirements, demolition workers will generally 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 mainly interested in the survey information about the relief and topography of the site. It is usually the case that they will need to assemble 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 project.
