Progressive Rants and Raves

The construction trade has a particular reputation for being a harsh atmosphere in which brute force takes priority 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 industry that is firmly rooted in the academic world.

One part of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This type 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.

Topographical Surveys

A topographical survey is a report of the physical features of a particular piece of land. The aim of a topographical survey is to map the naturally occurring and man-made traits of a specific landscape to a high degree of accuracy.

Topographical surveys could be carried out on a very wide range of landscapes, from open countryside to urban areas 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 number of tasks.

Common Applications for Topographical Surveys

Probably the most widely used, and most generally 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, elevations 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 business. When individuals or companies are looking to build any kind of structure they will need to perform extensive surveys as part of the design stage of the project. These surveys are often an indispensable part of any application for planning permission too.

Surveys also 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 ensure that they can guarantee the safety of their staff on site.

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 necessary 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. Whilst the information gathered by the survey will be very accurate, and might be very extensive, the purpose of these surveys is to give a site summary. They will usually be the first type of topographical survey that is carried out on a job.

These surveys will generally incorporate a boundary survey that sets out to define the extent of the site and spotlight any particular restraints that are determined by the geography of the site. They may also include a level survey that will measure the elevation of the land and the various gradients that exist.

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 survey is more regularly associated with the demolition industry because it can give a detailed plan of the building to be demolished. It can be used on other projects as well.

A building survey will probably include a measured survey, which entails creating a detailed plan of the exterior and interior dimensions of a building. Depending on the requirements of the job, a measured survey could provide simple 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 mentioned above. This information will be needed so that the demolition firm can plan a demolition that is both adequate and safe. Often these surveys will also be legally requested.

Surveys will often contain information about the energy services that are present on a site before any demolition or construction work happens. This is an important safety aspect since any unmonitored destruction to pipes and cables carrying water, gas and electricity might be very dangerous.

Another aspect of the site survey will often be an inventory of materials 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 utilised as hardcore or even timber. By getting an accurate audit of site materials the construction firm can more accurately gauge the need to import building materials, or they can re-use the materials on a different job. These surveys could be made pre-demolition as well as post-demolition.

It is an evident truth that prior to construction demolition should be done within sites containing existing houses and other structures.

Importance of Site Surveys

Possibly the most significant reason to perform a topographical site survey is to ensure the 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 condition 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 started. By then it may be too late to resolve these problems, or at best they will be expensive problems to solve.

The inventory of site materials, as previously stated, can be of great benefit to a demolition or construction enterprise 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 reused 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 machinery then a new access 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 stages of a construction project, the apparatus 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 equipment is both expensive and sensitive.

Once the demolition has occurred and the site has been deemed safe for personnel to return to it, the surveying equipment can be restored to its original position on site. This will allow for effective data collecting to take place for a post-demolition survey, and maintains a single point of contact for anyone who requires the topographical survey information. Most surveying firms will oversee this redeployment.

Project managers must consider secondary services such as concrete removal whilst scheduling various companies to carry out work on a building project.

Who can Perform Site Surveys?

Since topographical site surveys can play such a crucial role in the success or failure of a construction or demolition venture it is critical that they are undertaken carefully by the correct people. There are different branches of site surveying and each one will have specific certificates associated with it.

When selecting a company to undertake the surveying work necessary for your project it will be sensible to choose a company with a good reputation and a proven track record. Ask to see reviews of their previous work and try to get feedback about their performance on past 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 details 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.

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 regarding the physical relief of a site before the design phase, and a site materials record before they can prepare the construction phase. The more data that can be made available to project planners will assist 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 different requirements, demolition experts will generally 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 data about the relief and topography of the terrain. It is normally the case that they will want to build on a flat surface, so they will use details about the natural lay of the land to determine what work will be needed to create a stable footing for any structure.