The construction trade has a certain character for being a tough environment in which brute force takes precedence over calculated thinking; however this impression is far from appropriate. There is a huge amount of work that happens behind the scenes of the demolition and construction sector which is firmly grounded 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 great balance of specific technical know-how as well as experience of the industry and a natural intuition for the intricacies of the job.
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 specific landscape to a high degree of precision.
Topographical surveys could be carried out on a very wide range of landscapes, from open countryside to urban developments and across a variety of reliefs 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 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 generally recognised application for topographical surveys is cartography, or map making. Modern day maps include a great amount of detail about the landscape they relate to, including waterways, reliefs and ground surface, all of which will have been collected via a topographical survey.
Topographical surveys also have a key role to play in the construction industry. When people or companies are looking to construct any kind of structure they will need to undertake 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 definitely play a key safety role in primary industries like mining, or in other industrial sectors that interact with the land, such as demolition and infrastructure. Companies in these fields will use surveys to prepare their projects, but also to ensure that they can ensure the safety of their staff on site.
Standard topographical surveys are usually concerned with physical characteristics of land although building demolition surveys focus on man made buildings which are marked for demolition.
Types of Survey
The world of topography covers a large number of physical features so it is important to identify what type 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 designed to create an overview 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 objective of these surveys is to give a site summary.
These surveys will usually incorporate a boundary survey that sets out to determine the extent of the site and spotlight 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 land and the various gradients that exist. A 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 apparatus and even infrastructure features. This type of survey is more commonly associated with the demolition industry since it can give a detailed plan of the building to be demolished.
A building survey will probably include a measured survey, which involves creating a detailed plan of the external and internal proportions of a structure. 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.
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 that 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 prior to any demolition or construction work takes place. This is an important safety aspect since any unmonitored destruction to pipes and cables carrying water, gas and electricity might be very dangerous. The information can also be used to plan new buildings, based upon the existing supply of these utilities.
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 sorts of materials that can be found 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 project. These surveys can be made pre-demolition as well as post-demolition.
Topographical surveys and resource quantity reviews form one branch of demolition services provided by modern businesses that comply with business best practices.
Importance of Site Surveys
Perhaps the most significant reason to undertake a topographical site survey is to ensure the health and safety of the individuals who will be working on the site. The industrial sectors that most frequently call for site surveys are risky enough as it is without having to be concerned about the integrity of the ground on which they are working.
Another important reason to get a suitable survey done is to identify any potential problems that may arise because of the physical properties of the area. Certain things will not be evident on the surface of the site and will only be discovered once digging or demolition has started.
The inventory of site materials, as previously mentioned, can be of great benefit to a demolition or construction organisation working on a project. Not only are building materials themselves costly, but transporting them to the site may 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. Only by taking an accurate audit of these materials can a company properly plan its imported material requirements.
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 certain vehicles or equipment then a new entry route or alternative equipment will have to be found. Equally, a suitable 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 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 equipment is both costly and sensitive.
Once the demolition has taken place 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 effective data gathering to take place for a post-demolition study, and maintains a single point of contact for anybody who requires the topographical survey information.
Project managers must think about secondary provisions such as concrete removal when scheduling different companies to carry out work on a building project.
Who can Perform Site Surveys?
Because topographical site surveys can play such a crucial role in the success or failure of a construction or demolition venture it is vital that they are undertaken carefully by the right people. There are different branches of site surveying and each one will have unique qualifications associated with it. Finding surveyors with these specific qualifications will certainly be advantageous.
When selecting a company to undertake the surveying work necessary 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 performance on previous projects. It may also be worth considering how a company can deliver the 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 gathered by a site survey it needs to be handed 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. There will be less need for materials information half way through construction for example.
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 regarding 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 exterior properties of any building or structures that they are set to take down. Whilst every project will have individual requirements, demolition experts will typically need to know about the fundamental framework 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 site. 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 required to create a steady foundation for any structure.
