The construction trade has a certain character for being a harsh environment in which brute force takes priority over calculated thought; however this image is far from appropriate. There is a substantial amount of work that goes on behind the scenes of the demolition and construction industry which is firmly rooted in the academic arena. Furthermore, this unseen work is critical to the success of the more visible operations.
One part of this unnoticed work is site surveying, or more precisely 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 natural intuition for the complexities of the job.
Topographical Surveys
A topographical survey is a study of the physical features of a particular piece 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 accuracy. Whilst topography itself can refer to the surface of any kind of object, it is more commonly associated with the surface of the Earth.
Topographical surveys can be carried out on a very wide 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 number of tasks.
Common Applications for Topographical Surveys
Perhaps the most extensively used, and most generally recognised application for topographical surveys is cartography, or map making. Modern day maps include a great deal of information about the landscape they relate to, including waterways, reliefs and ground surface, all of which will have been gathered via a topographical survey. This information is also being made available online.
Topographical surveys also have a major role to play in the construction business. When individuals or companies are looking to construct any kind of structure they will need to carry out extensive surveys as part of the design stage of the project.
Surveys also play a key safety role in primary industries such as mining, or in other industries that interact with the land, such as demolition and infrastructure. Businesses in these fields will use surveys to prepare their projects, but also to be sure that they can ensure the safety of their workforce on site. As such, topographical surveys are often a legal prerequisite for these types of projects.
Engineers and building workers use building demolition surveys for specific sizes of interior and external constructions.
Types of Survey
The arena of topography addresses a large number of physical features so it is beneficial to determine what type of topographical survey is appropriate for a particular scenario. 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 fashioned to create an overview of the physical characteristics of any given plot of land. Whilst the information gathered by the survey will be extremely accurate, and might be very extensive, the objective of these surveys is to provide a site summary. They will often be the first type of topographical survey that is undertaken on a project.
These surveys will generally include 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 may 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 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 sector since 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 almost certainly include a measured survey, which entails creating a detailed plan of the external and interior proportions of a building. Depending on the requirements of the job, a measured survey could provide basic 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 details gathered by the types of boundary and building surveys described above. This information will be required so that the demolition company can plan a demolition that is both adequate and safe. Often these surveys will also be legally requested.
Surveys will often include information about the power services that are present on a site before any demolition or construction work happens. This is an important safety factor because any unmonitored damage to pipes and cables carrying water, gas and electricity could be very dangerous. The information can also be used to plan new structures, based upon the existing availability of these ammenities.
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 located on site, for example, tiles and masonry, concrete that can be utilised as hardcore or even timber. By taking an accurate audit of site materials the construction firm can more precisely gauge the need to import building materials, or they can re-use the materials on a different project.
One company with many years experience of the construction industry is East Midlands Demolition who add experience and expertise to demolition projects.
Importance of Site Surveys
Possibly the most significant reason to undertake a topographical site survey is to ensure the safety of the individuals who will be doing work on the site. The industrial sectors 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 identify 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 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 issues to solve.
The inventory of site materials, as previously mentioned, can be of great value to a demolition or construction organisation working on a project. Not only are building materials themselves expensive, but importing them to the site may be a very expensive task in itself. Any time that material can be reused on site provides an opportunity to save development time and money. Only by taking an exact audit of these supplies can a company properly plan its imported material requirements.
Topographical surveys can also highlight other areas that will be of use to the project managers. For example, if the gradients on a site would be prohibitive to particular vehicles or machinery then a new access route or alternative machinery will need to be found. Equally, an appropriate site will need to be found for the base of management 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 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 phase of a project since the machinery is both expensive and sensitive.
Once the demolition has taken place and the site has been deemed safe for workers 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 maintains a single point of contact for anybody who requires the topographical survey information. Most surveying firms will oversee this redeployment.
To truly rid the worksite of a building demolish the external structure and also the foundations it was built on.
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 project it is vital that they are undertaken thoroughly by the right people. There are different divisions of site surveying and each one will have unique certificates associated with it.
When selecting 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 performance on past 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 details has been accumulated by a site survey it must be passed out to the appropriate personnel on-site. Who gets what pieces of information will largely 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 concerning the physical relief of a site before the design phase, and a site materials inventory before they can plan the construction phase.
Demolition Experts
Demolition businesses will want to know about the interior and exterior characteristics of any building or structures that they are set to take down. Whilst every job 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 particularly interested in the survey data about the relief and topography of the terrain. It is usually 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 determine what work will be needed to create a steady footing for any building. They will want this information before and in the course of the construction stage of a project.
