The construction industry has a particular reputation for being a tough environment in which brute force takes priority over calculated thought; however this image is far from correct. There is a huge amount of work that goes on behind the scenes of the demolition and construction sector that is firmly rooted in the academic world. Moreover, this unseen work is critical to the success of the more visible operations.
One branch of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This sort of work calls for a good 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 plot of land. The purpose of a topographical survey is to chart the naturally occurring and man-made traits of a particular landscape to a high degree of precision.
Topographical surveys can 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 conditions or vegetation, and as such can be used for a multitude of tasks.
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 detail 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 major role to play in the construction industry. When individuals 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.
Surveys definitely play a key safety part in primary industries like mining, or in other industrial sectors that interact with the terrain, such as demolition and infrastructure. Organisations 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.
Under modern regulatory control, the experts that conduct demolition surveys ought to be well certified to guarantee the trustworthiness of the survey findings.
Types of Survey
The arena of topography covers a large number of physical characteristics so it is beneficial to determine what type of topographical survey is suitable for a particular situation. 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 characteristics of any given plot of land. Although the data gathered by the survey will be very accurate, and can 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 incorporate a boundary survey that sets out to determine 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 land and the numerous gradients that exist.
Building Surveys
Building surveys are more typically concerned with man-made structures on a site, including the surveying of special machines and even infrastructure features. This type of study is more regularly associated with the demolition industry since 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 entails creating a comprehensive plan of the external and interior dimensions of a structure. Depending on the requirements of the job, a measured survey could provide simple building “footprint” measurements, or might produce a highly 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 always include the details gathered by the types of boundary and building surveys described above. This information will be required so the demolition company can plan a demolition that is both satisfactory and safe.
Surveys will often include 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 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 resources on the site. This type of survey 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 utilised as hardcore or even wood. By taking an accurate audit of site materials the construction firm can more accurately gauge the need to import building resources, or they can re-use the materials on a different job.
Topographical surveys and resource quantity surveys make up a single branch of demolition services made available by contemporary companies that conform with business best practices.
Importance of Site Surveys
Maybe the most significant reason to undertake a topographical site survey is to ensure the health and safety of the people who will be doing work on the site. The industries that most frequently 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 important reason to get a proper survey done is to highlight 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 uncovered once digging or demolition has begun. By then it may be too late to deal with these problems, or at best they will be costly issues to solve.
The inventory of site materials, as previously mentioned, can be of great value to a demolition or construction enterprise working on a project. Not only are building materials themselves costly, but importing them to the site could 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. Only by taking an accurate audit of these materials can a company properly plan its imported material needs.
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 entry route or alternative machinery 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 stored 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 wise 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 initial position on site. This will allow for efficient data gathering to take place for a post-demolition study, and retains a single point of contact for anyone who requires the topographical survey information. Most surveying firms will oversee this redeployment.
The demand for strict measurement as well as preparing is critical in garage demolition projects because homes and other structures may be nearby.
Who can Perform Site Surveys?
Because topographical site surveys can play such a critical role in the success or failure of a construction or demolition project it is vital that they are undertaken carefully by the right people. There are different branches of site surveying and each one will have specific qualifications associated with it.
When choosing a company to undertake the surveying work necessary 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 overall 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?
When 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 performed, but can also rely on the stage that a project is at. There will be much less need for materials information half way through construction for example.
Project Planners
Project planners will generally require access to all of the information collected 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 inventory before they can plan the construction phase. The more data that can be made available to project planners will aid the smooth running of the project.
Demolition Experts
Demolition organisations will want to know about the interior and external characteristics of any building or structures that they are arranged 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.
Site Engineers
Construction engineers on-site will be particularly interested in the survey information 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 stable footing for any structure.