The construction trade has a certain character for being a tough environment in which brute force takes priority over calculated thinking; however this impression is far from appropriate. There is a substantial amount of work that happens behind the scenes of the demolition and construction sector which is firmly rooted in the academic world. Moreover, this unseen work is vital 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 actual features of a given plot of land. The purpose of a topographical survey is to map the naturally occurring and man-made features of a particular landscape to a high degree of accuracy.
Topographical surveys could 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 conditions or vegetation, and as such can be used for a multitude of tasks. A few of the more common uses are outlined below.
Common Applications for Topographical Surveys
Probably the most extensively used, and most commonly recognised application for topographical surveys is cartography, or map making. Modern maps include a great deal 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. This information is also being offered online.
Topographical surveys also have a key role to play in the construction business. When people or companies are looking to build any kind of structure they will need to undertake extensive surveys as part of the design stage 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. Companies in these fields will use surveys to plan their projects, but also to make sure that they can guarantee the safety of their staff on site.
Engineers as well as building staff employ building demolition surveys for in depth dimensions of internal and external constructions.
Types of Survey
The arena of topography covers a large number of physical features so it is important to determine what type of topographical survey is suitable for a particular situation. A few of the more common types of survey required 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. Although the information gathered by the survey will be very accurate, and might be very extensive, the purpose of these surveys is to provide a site summary. They will usually be the first type of topographical survey that is undertaken on a project.
These surveys will usually 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 measure 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 typically concerned with man-made structures on a site, including the surveying of special machines and even infrastructure characteristics. This type of study is more commonly associated with the demolition sector because it can give a detailed plan of the structure to be demolished. It can be used on other projects as well.
A building survey will probably include a measured survey, which involves creating a detailed plan of the exterior and interior proportions of a structure. Depending on the requirements of the project, a measured survey might provide basic building “footprint” dimensions, or might produce a very detailed plan of the structure. This information can be used to generate interior floor plans and even roof plans.
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 necessary so the demolition company can plan a demolition that is both satisfactory and safe.
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 important safety factor because any unmonitored destruction to pipes and cables carrying water, gas and electricity could be very dangerous.
Another aspect of the site survey will often be an inventory of materials on the site. This type of study will be a quantity survey of the various kinds 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 determine the need to import building materials, or they can re-use the materials on a different project.
Even though it is a required short-term expense, a pre demolition survey could produce economic benefits in the long-term by highlighting potential problems.
Importance of Site Surveys
Maybe the most significant reason to perform a topographical site survey is to ensure the safety of the people who will be working on the site. The industries that most commonly 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.
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 area. Certain things will not be evident on the surface of the site and will only be uncovered once digging or demolition has begun.
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 costly, but transporting them to the site could 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. Only by taking an exact audit of these materials can a company properly plan its imported material needs.
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 certain vehicles or machinery then a new entry route or alternative equipment will have to be found.
Positioning of Survey Control
During the surveying and construction phases of a building project, the equipment required for the physical surveying of the site and control of the survey information will often be kept on-site. This is obviously a problem when it comes to the demolition period 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 occurred and the site has been deemed safe for staff 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 survey, and maintains a single point of contact for anybody who needs the topographical survey information. Most surveying firms will oversee this redeployment.
Las Vegas is the setting to much commercial demolition since older hotels need flattening so that more modern 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 building or demolition venture it is critical that they are carried out carefully by the correct people. There are different divisions of site surveying and each one will have specific qualifications associated with it. Finding surveyors with these specific skills 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 get feedback about their overall performance on previous projects. It may also be worth thinking about how a company can deliver their survey data, 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 information has been accumulated by a site survey it needs to be passed out to the appropriate personnel 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 generally require access to all of the information gathered by a topographical survey, although 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 plan the construction phase. The more information that can be made available to project planners will aid the smooth running of the venture.
Demolition Experts
Demolition businesses will want to know about the interior and external characteristics of any building or structures that they are arranged to take down. Whilst every project will have different requirements, demolition experts 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 statistics 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 information about the natural lay of the land to calculate what work will be needed to create a steady footing for any building.