The demolition trade has a particular reputation for being a harsh atmosphere in which brute force takes priority over calculated thought; however this impression is far from correct. There is a huge amount of work that happens behind the scenes of the demolition and construction sector that is firmly rooted in the academic arena. Furthermore, this unseen work is vital to the success of the more visible procedures.
One part of this unnoticed work is site surveying, or more specifically 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 natural intuition for the complexities of the job.
Topographical Surveys
A topographical survey is a report of the actual features of a particular piece of land. The aim of a topographical survey is to map the naturally occurring and man-made features of a specific landscape to a high degree of precision. Whilst topography itself can refer to the surface of any 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 number of factors, such as ground conditions 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 commonly 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, elevations and ground surface, all of which will have been obtained via a topographical survey. This information is also being made available online.
Topographical surveys also have a key role to play in the construction business. When individuals or companies are looking to construct any kind of structure they will need to undertake extensive surveys as part of the design phase of the project.
Surveys definitely play a key safety part in primary industries such as mining, or in other industrial sectors that interact with the terrain, such as demolition and infrastructure. Companies in these fields will use surveys to plan their projects, but also to ensure that they can ensure the safety of their workforce on site. As a result, topographical surveys are often a legal prerequisite for these types of projects.
Although it is not always the best option, some sort of demolition survey can always be conducted while preparation work is taking place on-site.
Types of Survey
The world of topography covers a large number of physical features so it is beneficial to determine 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 discussed below.
"Lie of the land" Surveys
These types of topographical surveys are fashioned to create an overview of the physical properties of any given plot of land. Although the data gathered by the survey will be very accurate, and can be very extensive, the objective of these surveys is to give a site summary. They will often be the first type of topographical survey that is carried out on a project.
These surveys will usually incorporate a boundary survey that sets out to determine the extent of the site and highlight 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 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 structures on a site, including the surveying of special equipment and even infrastructure features. This type of study is more regularly associated with the demolition sector because it can give a detailed plan of the building to be demolished. It may be used on other projects as well.
A building survey will almost certainly include a measured survey, which involves 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 basic building "footprint" measurements, or might produce a very detailed plan of the structure. This information can be used to create interior floor plans and even roof plans.
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 needed so that the demolition company 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 happens. This is an essential safety factor since any unmonitored damage to pipes and cables carrying water, gas and electricity could be very dangerous.
Another aspect of the site survey will often be an audit of materials on the site. This type of survey will be a quantity survey of the various sorts of materials that can be located on site, for example, tiles and masonry, concrete that can be utilised 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 materials, or they can re-use the materials on a different project. These surveys could be made pre-demolition and post-demolition.
Project planners may discover financial savings once topographical demolition surveys summarise supplies quantities currently on-site that can be recycled.
Importance of Site Surveys
Possibly the most significant reason to undertake a topographical site survey is to ensure the health and safety of the people who will be working on the site. The industries that most frequently call for site surveys are risky enough as it is without having to worry about the integrity of the ground on which they are working.
Another critical reason to get a proper survey done is to identify any potential difficulties that may arise because of the physical characteristics of the region. Certain things may not be evident on the surface of the site and will only be discovered once digging or demolition has begun.
The inventory of site supplies, as previously stated, can be of great value to a demolition or construction organisation working on a project. Not only are construction materials themselves costly, but transporting 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 funds.
Topographical surveys can also highlight 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 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 expensive 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 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 much commercial demolition because old hotels need flattening so that new ones may be built in their place.
Who can Perform Site Surveys?
Because topographical site surveys can play such a vital role in the success or failure of a building or demolition venture it is critical that they are undertaken thoroughly by the right people. There are different branches of site surveying and each one will have specific qualifications associated with it. Getting surveyors with these specific qualifications will certainly be beneficial.
When selecting 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 examples of their previous work and try to obtain feedback about their performance on previous projects. It may also be worth considering 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?
Once an adequate level of information has been gathered 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 performed, 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 about 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 internal and external properties of any building or structures that they are set to take down. Whilst every job 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. They will need this knowledge 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 information about the natural lay of the land to calculate what work will be needed to create a steady footing for any structure. They will want this information before and during the construction stage of a project.