Construction

Featuring:-

Slab design and earthworks quantities
Take 2D design data and convert to 3D using digitising and CAD import functions
Earthworks calculations and design
Areas and volumes (including construction depth allowance)
Cut/Fill Lines
Topsoil strip calculations
Plans and cross-sections
Level difference models (isopachytes)
Floor level assessments
Setting-out
CAD data transfer

much more...

LSS is the ideal tool for measuring, designing, monitoring and visualising a wide range of projects within the Construction industry.

Most Construction users are on Vista or Elite because they require sections and volumes and, in many cases, benefit from the powerful and unique advanced volume calculation options, which are an important part of LSS. Especially useful for tendering, the volumes by zones and volumes to construction depth have proved invaluable on many major projects.

With the building elevation survey option in Solo, it is also possible to survey existing buildings and structures for a variety of purposes.

Some concrete proposals

An article by Ian Kemp, Senior Engineering Surveyor, Skanska

I've worked on a lot of construction projects which have involved the laying of concrete slab floors and frequently encounter situations such as the one shown in this photograph.

Ideally you’d have a smooth surface without any depressions. After a spot or two of rain you can see the depressions in this concrete floor, but quantifying this unevenness can be a time consuming job. Traditionally, this has been called a 'puddleometer' for obvious reasons.

The “National Structural Concrete Specification for Building Construction, 3rd Ed. 2004” (NSCS) sets out the precise parameters within which everyone in the construction industry works.

In NSCS Part 1 there are three specific measures, two for the overall level of the concrete floor and one which specifies the waviness of the surface. Let's look at each in turn.

1) Permissible deviation from intended level shall be ±10mm. This means that nowhere on the floor should be more than 10mm higher or lower than the designed level. But, further…

2) Deviation in level between two points 6m apart shall be less than 15mm

3) Deviation at any point under a 3m straight edge placed at any position on the floor shall be less than 10mm

Determining whether a floor is level is quite straightforward, but when it comes to measuring the waviness of the surface, relying on someone laying a 3m straight edge at exactly the right place is difficult and ultimately not traceable. So, what we did was approach McCarthy Taylor to see if there was anything they could do with LSS to help us work out these measurements. After a development meeting with Bryan Taylor it wasn't long before we had a working solution to our problem in the form of 'Output / Floor Assessment'.

This is how we do it now. Using a Leica TCRM 1201 EDM with reflectorless measuring capability we take a roughly 1 metre grid of points straight onto the dry (and clean) concrete surface. At the same time we also pick up other as-built information such as the position of columns, walls, slab edges, drainage and recesses. The floor information is then filtered into an LSS model, surface coded and the Floor Assessment run.

We are then able to run three analyses. 1) The deviation of the floor from the design level 2) The level deviation over any stipulated distance of usually 6 metres and 3) the deviation relative to a straight edge of usually 3 metres.

So, for every grid position LSS effectively draws a line through the model and then repeats the exercise, this time rotated by a user-defined interval until it has completed a full 360 degrees. If we want to know the deviation from design of suspended floor thickness we run a separate analysis which compares surveys of the top and bottom of the same slab, stored as separate surveys in LSS.
The results show clearly where the design tolerances have and have not been met. In fact, on an individual project the specification may call for even tighter tolerances, such as when the finished floor needs to be smoother, such as in plant rooms or where heavy machinery is being wheeled around. What the contractor wants to avoid is having to grind down whole areas of the floor because it is too high. For instance, if a floor is 15mm too high across its entire surface, but we have sufficient headroom to accommodate it, we may decide to alter the design as long as it doesn't impact on other aspects of the build.

What we see here isn't the consequence of a bizarre game of 'Pick-up-sticks', it's the result of the 3m straight edge calculation. The lines represent where the stipulated deviation has been exceeded and requires some attention. Below we see the result of a level analysis. The coloured heightbands represent the difference between design and built levels for the floor. In this example, blues represent 'below design', browns represent 'above design' and greens are within tolerance of design.

What the new Floor Assessment command does is allow us to quantify the floor characteristics and compare them to the design and project specifications. Critically, it allows us to do this using standard survey equipment which we already have on-site. The quality of the results and the cost savings make this a win-win for us and our clients.

The Floor Assessment command is available in LSS Elite.

CONSTRUCTION
Featuring:- Slab design and earthworks quantities Take 2D design data and convert to 3D using digitising and CAD import functions Earthworks calculations and design Areas and volumes (including construction depth allowance) Cut/Fill Lines Topsoil strip calculations Plans and cross-sections Level difference models (isopachytes) Floor level assessments Setting-out CAD data transfer much more... LSS is the ideal tool for measuring, designing, monitoring and visualising a wide range of projects within the Construction industry. Most Construction users are on Vista or Elite because they require sections and volumes and, in many cases, benefit from the powerful and unique advanced volume calculation options, which are an important part of LSS. Especially useful for tendering, the volumes by zones and volumes to construction depth have proved invaluable on many major projects. With the building elevation survey option in Solo, it is also possible to survey existing buildings and structures for a variety of purposes. Some concrete proposals An article by Ian Kemp, Senior Engineering Surveyor, Skanska I've worked on a lot of construction projects which have involved the laying of concrete slab floors and frequently encounter situations such as the one shown in this photograph. Ideally you’d have a smooth surface without any depressions. After a spot or two of rain you can see the depressions in this concrete floor, but quantifying this unevenness can be a time consuming job. Traditionally, this has been called a 'puddleometer' for obvious reasons. The “National Structural Concrete Specification for Building Construction, 3rd Ed. 2004” (NSCS) sets out the precise parameters within which everyone in the construction industry works. In NSCS Part 1 there are three specific measures, two for the overall level of the concrete floor and one which specifies the waviness of the surface. Let's look at each in turn. 1) Permissible deviation from intended level shall be ±10mm. This means that nowhere on the floor should be more than 10mm higher or lower than the designed level. But, further… 2) Deviation in level between two points 6m apart shall be less than 15mm 3) Deviation at any point under a 3m straight edge placed at any position on the floor shall be less than 10mm Determining whether a floor is level is quite straightforward, but when it comes to measuring the waviness of the surface, relying on someone laying a 3m straight edge at exactly the right place is difficult and ultimately not traceable. So, what we did was approach McCarthy Taylor to see if there was anything they could do with LSS to help us work out these measurements. After a development meeting with Bryan Taylor it wasn't long before we had a working solution to our problem in the form of 'Output / Floor Assessment'. This is how we do it now. Using a Leica TCRM 1201 EDM with reflectorless measuring capability we take a roughly 1 metre grid of points straight onto the dry (and clean) concrete surface. At the same time we also pick up other as-built information such as the position of columns, walls, slab edges, drainage and recesses. The floor information is then filtered into an LSS model, surface coded and the Floor Assessment run. We are then able to run three analyses. 1) The deviation of the floor from the design level 2) The level deviation over any stipulated distance of usually 6 metres and 3) the deviation relative to a straight edge of usually 3 metres. So, for every grid position LSS effectively draws a line through the model and then repeats the exercise, this time rotated by a user-defined interval until it has completed a full 360 degrees. If we want to know the deviation from design of suspended floor thickness we run a separate analysis which compares surveys of the top and bottom of the same slab, stored as separate surveys in LSS. The results show clearly where the design tolerances have and have not been met. In fact, on an individual project the specification may call for even tighter tolerances, such as when the finished floor needs to be smoother, such as in plant rooms or where heavy machinery is being wheeled around. What the contractor wants to avoid is having to grind down whole areas of the floor because it is too high. For instance, if a floor is 15mm too high across its entire surface, but we have sufficient headroom to accommodate it, we may decide to alter the design as long as it doesn't impact on other aspects of the build. What we see here isn't the consequence of a bizarre game of 'Pick-up-sticks', it's the result of the 3m straight edge calculation. The lines represent where the stipulated deviation has been exceeded and requires some attention. Below we see the result of a level analysis. The coloured heightbands represent the difference between design and built levels for the floor. In this example, blues represent 'below design', browns represent 'above design' and greens are within tolerance of design. What the new Floor Assessment command does is allow us to quantify the floor characteristics and compare them to the design and project specifications. Critically, it allows us to do this using standard survey equipment which we already have on-site. The quality of the results and the cost savings make this a win-win for us and our clients. The Floor Assessment command is available in LSS Elite.