The construction trade has a certain character for being a harsh atmosphere in which brute force takes priority over calculated thinking; however this image is far from correct. There is a huge amount of work that happens behind the scenes of the demolition and construction industry which is firmly rooted in the academic arena.
One branch of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This type of work demands a great balance of specific technical know-how as well as experience of the industry and a genuine intuition for the complexities 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 piece of land. The aim of a topographical survey is to chart the naturally occurring and man-made features of a particular landscape to a high degree of accuracy. Whilst topography itself may refer to the surface of virtually any object, it is more commonly associated with the surface of the Earth.
Topographical surveys can be carried out on a very wide 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 number of factors, such as ground variables 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 day maps include a great amount of information about the landscape 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 industry. When individuals or companies are looking to construct any kind of structure they will need to carry out extensive surveys as part of the design phase of the project.
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. Businesses in these fields will use surveys to plan their projects, but also to make sure that they can ensure the safety of their staff on site. As such, topographical surveys are often a legal requirement for these types of projects.
A site due for demolition tasks should undergo a demolition survey for employee safety as well as monetary planning motives.
Types of Survey
The world of topography covers a large number of physical features so it is important to identify what form of topographical survey is suitable for a particular scenario. A few of the more common types of survey necessary for construction sites are reviewed below.
“Lie of the land” Surveys
These types of topographical surveys are designed to create a summary of the physical properties of any given plot of land. Whilst the information gathered by the survey will be extremely accurate, and might be very extensive, the objective of these surveys is to give a site summary.
These surveys will generally include a boundary survey that sets out to define the extent of the site and highlight any specific restraints that are determined by the geography of the site. They can also include a level survey that will plot the elevation of the terrain and the various gradients that exist. Any survey can be customised to specification though.
Building Surveys
Building surveys are more generally concerned with man-made constructions on a site, including the surveying of special machines and even infrastructure features. This type of study is more commonly associated with the demolition industry since it can give a detailed plan of the building to be demolished. It can be used on other projects as well.
A building survey will probably include a measured survey, which entails creating a precise plan of the external and internal dimensions of a building. 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 always 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 adequate and secure.
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 essential safety factor because any unmonitored destruction to pipes and cables carrying water, gas and electricity could be very dangerous. The information could also be used to plan new structures, based upon the existing supply of these utilities.
Another aspect of the site study will often be an audit of materials on the site. This type of study will be a quantity survey of the various kinds of materials that can be located on site, for example, tiles and masonry, concrete that can be used as hardcore or even wood. By getting an accurate audit of site materials the construction company can more accurately determine the need to import building materials, or they can re-use the materials on a different job. These surveys can be made pre-demolition and post-demolition.
Project planners may discover financial savings after topographical demolition surveys collect material quantities currently on-site that can be re-used.
Importance of Site Surveys
Maybe the most significant reason to perform a topographical site survey is to ensure the health and safety of the individuals who will be doing work on the site. The industries 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.
Another critical reason to get a proper survey done is to highlight any potential difficulties that may arise because of the physical properties of the region. Particular things may not be evident on the surface of the site and will only be discovered once digging or demolition has begun. By then it may be too late to fix these problems, or at best they will be costly problems to solve.
The inventory of site materials, as previously mentioned, can be of great benefit to a demolition or construction enterprise working on a project. Not only are construction materials themselves costly, but importing them to the site may be a very expensive task in itself. Any time that material can be recycled on site provides 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 have to be found.
Positioning of Survey Control
During the surveying and construction phases of a building project, the apparatus required for the physical surveying of the site and control of the survey information will often be stored on-site. This is clearly a problem when it comes to the demolition phase of a project since the machinery is both costly and sensitive. It is therefore sensible to move this equipment off-site during demolition.
Once the demolition has taken place and the site has been deemed safe for workers to return to it, the surveying equipment can be restored to its original position on site. This will allow for effective data gathering to take place for a post-demolition study, and retains a single point of contact for anyone who needs the topographical survey information. Most surveying firms will oversee this redeployment.
Las Vegas is the setting for a good deal of commercial demolition since old hotels require flattening so that newer ones may be built in their place.
Who can Perform Site Surveys?
Since topographical site surveys can play such a vital role in the success or failure of a construction or demolition project it is vital that they are carried out thoroughly by the right people. There are different branches of site surveying and each one will have unique certificates associated with it.
When choosing a company to undertake the surveying work required for your project it will be sensible to choose a business with a good reputation and a proven track record. Ask to see reviews of their previous work and try to obtain feedback about their overall performance on past 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 largely depend on the job roles being executed, but can also rely on the stage that a project is at. There will be less need for materials information midway through construction for example.
Project Planners
Project planners will generally 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 prepare 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 set to take down. Whilst every project will have individual requirements, demolition workers will generally need to know about the fundamental structure of a building and the materials it is made out of. They will need this knowledge before demolition can take place.
Site Engineers
Construction engineers on-site will be mainly interested in the survey data about the relief and topography of the site. It is usually the case that they will want to assemble on a flat surface, so they will use information about the natural lay of the land to calculate what work will be required to create a steady footing for any structure. They will want this information before and in the course of the construction stage of a project.