Site Surveying
The demolition trade has a particular reputation for being a harsh atmosphere in which brute force takes precedence over calculated thinking; 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 sector which is firmly grounded in the academic world.
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 great balance of specific technical understanding as well as experience of the industry and a natural intuition for the intricacies of the job. This article explores the ins and outs of this work.
Topographical Surveys
A topographical survey is a study 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 specific landscape to a high degree of accuracy. Whilst topography itself can refer to the surface of virtually any object, it is more commonly associated with the surface of the planet.
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 developed to take into account a great many factors, such as ground variables or vegetation, and as such can be used for a number of tasks.
Common Applications for Topographical Surveys
Perhaps the most widely used, and most generally recognised application for topographical surveys is cartography, or map making. Modern maps include a great deal of detail 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 key role to play in the construction industry. When people or organisations are looking to build 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 like mining, or in other industries that interact with the land, such as demolition and infrastructure. Organisations in these industries will use surveys to prepare their projects, but also to make sure that they can ensure the safety of their workforce on site.
On sites where there are buildings to be demolished, building demolition surveys generally aid planners throughout the demolition phase of the project.
Types of Survey
The world of topography addresses 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 typical 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 properties of any given plot of land. Although the data gathered by the survey will be very accurate, and might 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 determine 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 plot the elevation of the terrain and the various gradients that exist. A survey can be customised to specification though.
Building Surveys
Building surveys are more typically concerned with man-made constructions on a site, including the surveying of special apparatus and even infrastructure features. This type of study is more commonly associated with the demolition industry because it can give a detailed plan of the building to be demolished. It can be used for other projects as well.
A building survey will almost certainly include a measured survey, which involves creating a detailed plan of the exterior and interior dimensions of a structure. Depending on the requirements of the job, a measured survey might provide simple building “footprint” measurements, or might produce a highly detailed plan of the structure.
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 described above. This information will be needed so the demolition firm can plan a demolition that is both satisfactory and safe. Often these surveys will also be legally required.
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 important safety factor since any unmonitored destruction to pipes and cables carrying water, gas and electricity might be very dangerous.
Another aspect of the site study will often be an inventory of resources on the site. This type of survey will be a quantity survey of the various kinds of materials that can be located on site, for example, tiles and masonry, concrete that can be used as hardcore or even timber. By getting an accurate audit of site materials the construction company can more precisely determine the need to import building resources, or they can re-use the materials on a different job.
Carrying out a thorough , comprehensive house demolition survey ensures the health and safety of residents in the immediate locality of the work site.
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 industrial sectors that most frequently call for site surveys are dangerous 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 characteristics of the area. Particular things will not be evident on the surface of the site and will only be discovered once digging or demolition has begun. 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 enterprise working on a project. Not only are building materials themselves expensive, 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.
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 certain vehicles or equipment then a new entry route or alternative equipment 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 stage of a project since the machinery is both expensive and sensitive.
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 survey, and keeps a single point of contact for anyone who needs the topographical survey information.
One of the most specialist parts of industrial demolition concerns the removal of hazardous materials that may be damaging to the natural environment.
Who can Perform Site Surveys?
Because topographical site surveys can play such a vital role in the success or failure of a construction or demolition project it is vital that they are carried out thoroughly by the right people. There are different branches of site surveying and each one will have unique certificates associated with it.
When choosing a company to undertake the surveying work required for your project it will be sensible 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 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 accumulated by a site survey it must be passed out to the appropriate personnel 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. There will be much less need for materials information midway through construction for example.
Project Planners
Project planners will generally need 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 plan the construction phase. The more information that can be made available to project planners will aid the smooth running of the project.
Demolition Experts
Demolition companies will want to know about the internal and external 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. They will need this information before demolition can take place.
Site Engineers
Construction engineers on-site will be mainly interested in the survey statistics about the relief and topography of the terrain. It is usually the case that they will need to assemble on a flat surface, so they will use details about the natural lay of the land to calculate what work will be needed to create a stable foundation for any building.
