They are easily seen around every construction site with large equipment. Most of the time, people see them along roads squinting through camera-like devices that are stationed on pretty tripods.
So, what exactly do these people do? Well, they work in construction and they are called land surveyors. But what does the land surveyor do? What are their primary responsibilities and why are they essential in the smooth BIM construction project?
The role and responsibility of a land surveyor.
While everyone has heard of a land surveyor, not everyone know the roles and responsibilities that these skilled individuals bring to a construction project. When I had asked somebody about the job functions of a land surveyor, he had answered vaguely, only mumbling something about measurement and land development.
Exactly!!! He wasn’t far off from the answer. In construction projects, the surveyors examine the land and they also perform some active jobs on-site such as machine guidance accuracy control measurements and so on.
They take and record precise measurements, they locate the boundaries of various sites, they identify baselines for construction projects, confirm the heights of building foundations on-site, and generally interpret mapped construction plans into series of spatially accurate surface coordinates. Furthermore, construction surveyors also deal with reference points.
Interpreting a building foundation design on site.
Great, the Architect has finally designed a new building project to be constructed. He had passed it down to the Civil Engineer, who had done all necessary structural calculations to come up with a building structure that will withstand the test of time. But we are stuck!!!
We don’t know how to easily transfer this awesomely designed building structure into a real world. Oh, not to worry, this is where the surveyor comes in. Armed with his GPS-enabled automatic survey equipment that comes fully loaded with maps and documents for land surveys, this expert land developer gladly accepts his job responsibility.
So, he gets a copy of the designed building project and locates the foundations of the building as designed by the engineer. He notices the grid lines and the reference point, he establishes his baseline and then he sets off to work.
He brings out his most valuable tool – the EDM – known as the Electronic Distance Measurement. With this gear he measures out the area for the building construction on the site, he then includes the angular measurements to the already measured outlines.
Carefully, he relates the building design to the topographical nature of the ground of the construction site, after which he is easily able to assign a set of coordinated points on the site layout to indicate the various parameters of the building foundation. As for the reference points, they are baselines like existing land points or an existing building that are on the land survey.
These reference points are used as references or starting points for the building. All other points are derived from this reference points to ascertain the general layout of the building structure.
While they are typically seen around building construction sites, it is simply amazing that the surveyors also interpret bridge designs on actual land as well as any other Civil Engineering infrastructure, in other to conform to both the requirements of the government as well as general construction standards.
Working with other site personnel
It is not easy to imagine the amount of calculations that the construction surveyors do. The longitude and latitude measurements have to conform to the Cartesian system of coordinates, while they also have to pull out old land survey documents from their archives. To a certain point too, the surveyor while working in teams can travel a lot.
They walk extensively throughout the project site; they identify and mark out channels for drainage in addition to tracking cables for power lines. Mounting their EDM on an attractive tripod, the main surveyor communicates with the rest of the surveying team.
The other surveyor stays close to the EDM as he squints through the camera lens to obtain the distance and angle of specified points on the site. When all is said and done, the building structure that had been designed by the architect and structurally-detailed by the Civil Engineer is oriented and scaled in such a way that it fits into the reference points as well as spatial coordinates.
After that, the site ground is leveled with the use of bulldozers, and it is subsequently graded with the proper earth moving machine. After this, all the necessary infrastructural elements are laid and installed.
Using of Machine guidance equipment for earthworks
With all the building attributes and plans easily inputted into a software system, a machine guidance system that is calibrated to an earth-moving machine is brought in to perform large earthmoving tasks.
Naturally, as the main Site supervisor responsible for the actual site points, the surveyor supervises the machine performing its task which generally ranges from trenching, cutting, grading, leveling, filling, excavating, drilling and so on. While an earthmoving machine is needed on-site to perform large and bulky earthmoving tasks, the surveyor stays at hand to control and supervise the operator of the machine to ensure that the right thing is done.
Root causes of the problems associated with the site surveyor.
- Unskilled Surveyors: The unskilled Surveyor is a source of problems for the construction surveyor, the lack of skill on creating well functioning machine guidance models, management of log points as well as the preparation of the digital delivery has put many surveyors into fear.
- Old world habits: Before now, you could easily find very experienced and knowledgeable Surveyors. However, now that the BIM-based construction has been commercially introduced into construction, most of the infrastructure construction is now being done by machine guided excavators, bulldozers and total station equipped graders; the game has been completely changed. Due to this, Surveyors are no longer required to set up sticks and paint all over the work site to communicate to other members of the workforce where to dig and how deep. This new age and technology require them to focus entirely on new areas and old habits die hard.
- Massive workload: While we are still at the same situation that we were at 40 years ago, where surveyors were so busy that they spent all day and all night in the construction site. Despite days of surveying and nights of crunching numbers, managing quality log points and planning the next day, BIM and BIM-based production methods have still added more workload to their daily routines. It comes naturally from foremen to delegate all these “BIM stuff” to the surveyor as he is mostly close to it on-site. By not sharing the responsibilities and tasks that comes with the BIM-based production, it will damage the efficiency and the quality of the overall project.
- Surveyor Team Myth: It has become a myth to have surveyor teams these days. If the project is below 10m Euros, there would be just one surveyor working part-time. If the job was up to about 40m Euros, there would be about 2 or 3 surveyors. However, this depends on the project too of course. This lack of adequate surveyors has resulted to pains to the project team as well as to the surveyor too. If the surveyor doesn’t get the BIM-based production right from the start, the whole project is in risk of failure.
Solution to the root causes of the problems of Site surveyor.
The responsibility of the site surveyor is an enormous task and it requires a great deal of skill and diligence. Most problems of the site surveyors are solved by the provision of the right type of equipment for each project. Every project is unique and demands its surveying tools.
The surveying tools used for a building project are quite different from those used on an earthwork project and have different levels of sophistication. With that said, the surveyor also has to be trained to eliminate any grey area he may be having on his job. Naturally, surveyor training could take care of site planning and direction, the use of surveying tools and techniques as well as any function that he may encounter during his daily surveying task.
The construction surveyor is just as important as the Architects and Engineers that had designed the building. Hence, they should be fully equipped with knowledge and equipment to effectively perform their roles and responsibilities. As key site personnel, they are needed to set the ground limits for a construction project to commence.
The newly introduced GPS-survey tools can be taught to site foremen as well as site engineers. These tools have gone through several innovations and have made site survey simple, effortless and interesting. The GPS-survey is typically integrated into a BIM-based construction system. With this functionality, the surveyors have no need of marking any area for digging or filling of earthworks. But except, in the construction of rigid structures such as foundations or bridges, then the surveyor have to be present.
With the complete absence of poles telling the site foremen the accurate location as well as how deep to dig, this is where the GPS-receivers come into play. Foremen and other workforce can utilize the GPS-receivers to see what is been built around the surrounding area. Furthermore, the GPS-receiver tells the site foremen how much from the current earth-level they need to dig or fill to achieve the target layer.
Furthermore, when excavators as well as the bulldozers (and workmen equipped with GPS-receivers) are taking the log points on structures which has about =3cm accuracy, the surveyor can focus on coordinating the effort of the surveying, the taking of the total station measurement of rigid structures as well as managing all quality points in order to ensure the construction is properly done.
Additionally, it is recommended that construction companies invest on having BIM teams in within their organizations. These BIM teams assist surveyors on creating the surface models for machine guided excavators and bulldozers and taking part on managing the whole information management aspect of the construction project with the log points included.
Furthermore, minimizing the enormous quantity of work by having well formed processes as well as work methods of utilizing and benefitting from BIM-based construction practices helps to ease up surveyors work.