The construction industry has a certain reputation for being a tough atmosphere in which brute force takes precedence over calculated thought; however this impression is far from appropriate. There is a substantial amount of work that goes on behind the scenes of the demolition and construction industry which is firmly rooted in the academic arena. Furthermore, this unseen work is critical to the success of the more visible operations.
One part of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This sort of work calls for 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 physical features of a given piece of land. The aim of a topographical survey is to map the naturally occurring and man-made traits of a particular landscape to a high degree of accuracy. Whilst topography itself may refer to the surface of any object, it is more commonly associated with the surface of the Earth.
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 developed 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 widely used, and most commonly 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 major role to play in the construction industry. When people or organisations are looking to build 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 important part of any application for planning permission as well.
Surveys also play a key safety role in primary industries such as mining, or in other industrial sectors that interact with the land, such as demolition and infrastructure. Organisations in these fields will use surveys to prepare their projects, but also to be sure that they can guarantee the safety of their staff on site. As such, topographical surveys are often a legal requirement for these types of projects.
Although it is not always the greatest solution, some sort of demolition survey may be conducted while preparation work is happening on-site.
Types of Survey
The arena of topography covers a large number of physical features so it is important to identify what type of topographical survey is appropriate for a particular scenario. 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 an overview of the physical characteristics of any given plot of land. Whilst the data gathered by the survey will be very accurate, and may be very extensive, the purpose 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 particular restraints that are determined by the geography of the site. They can also include a level survey that will measure the elevation of the land and the numerous 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 characteristics. This type of survey is more commonly associated with the demolition industry since it can give a detailed plan of the structure to be demolished. It may be used on other projects as well.
A building survey will almost certainly include a measured survey, which entails creating a detailed plan of the external and internal dimensions of a building. Depending on the requirements of the project, 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 details 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 secure. More often than not these surveys will also be legally requested.
Surveys will often include information about the power services that are present on a site prior to any demolition or construction work takes place. This is an essential safety factor because any unmonitored destruction to pipes and cables carrying water, gas and electricity could be very dangerous.
Another aspect of the site study will often be an inventory of resources on the site. This type of study will be a quantity survey of the various types of materials that can be found 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 company can more accurately gauge the need to import building materials, or they can re-use the materials on a different project.
Practically all construction sites require topographical demolition surveys since legislation and health and safety have become essential conditions.
Importance of Site Surveys
Maybe the most significant reason to perform a topographical site survey is to ensure the 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 worry about the condition of the ground on which they are working.
Another critical reason to get a suitable survey done is to highlight any potential problems that may arise because of the physical properties of the area. Certain 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 deal with these problems, or at best they will be expensive issues to solve.
The inventory of site supplies, 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 transporting them to the site may be a very expensive task in itself. Any time that material can be reused 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 planners. For example, if the gradients on a site would be prohibitive to specific vehicles or machinery then a new access route or alternative machinery will need to be found.
Positioning of Survey Control
During the surveying and construction phases of a construction project, the equipment required for the physical surveying of the site and control of the survey data will often be stored on-site. This is clearly a problem when it comes to the demolition period 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 maintains a single point of contact for anybody who needs the topographical survey information. Most surveying companies will oversee this redeployment.
Las Vegas is the setting to a good deal of commercial demolition since older hotels need flattening so that newer ones may be built in their place.
Who can Perform Site Surveys?
Because topographical site surveys can play such a crucial role in the success or failure of a building or demolition project it is critical that they are carried out thoroughly by the correct people. There are different branches of site surveying and each one will have unique qualifications associated with it. Getting surveyors with these specific skills will certainly be advantageous.
When selecting a company to undertake the surveying work required for your project it will be wise 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 performance on past projects.
Who will use the Survey Information?
Once an adequate level of information has been gathered by a site survey it needs to be passed out to the appropriate people on-site. Who gets what 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, although they will particularly need to use information concerning the physical relief of a site before the design phase, and a site materials inventory before they can plan the construction phase.
Demolition Experts
Demolition businesses will want to know about the interior and external properties of any building or structures that they are arranged to take down. Whilst every project will have individual requirements, demolition workers 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 mainly interested in the survey data about the relief and topography of the terrain. It is usually the case that they will need to build 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 stable footing for any structure. They will want this information prior to and during the construction stage of a project.
