CONSTRUCTION

Roads

On estate roads we find that contractors tend to bone along their length, typically with profiles 2m offset and set to a comfortable working height  for the men on site.  Typically FRL +1.5m…1.75m…2.0m etc.

Contractors vary the way in which they construct their roads.  Some may lay their kerbs and then string across to get their road formation, others may stone the road and use a machine to lay the kerb lines.  We have found that methods of road construction vary from contractor to contractor.  However it is done, we will match our work to the contractors requirements.

On major highways we find that contractors like to bone across the carriageways.  Where the road is cambered the profiles would be ‘double headers’, so we would calculate the level of the channel at the offset.   The contractor would bone across the road using the corresponding profile heads.

At Isis Reach in Belvedere, whilst working for GSE Construction, we worked on a very challenging road project where the profile of the road, due to poor ground conditions was very similar to a bridge deck.

The construction was reinforced concrete, topped with a wearing course and consisted of ‘beams’ running along its length, with the road spanning across.  The road was 400m in length, sat on piles, which had to be cut down to the correct level to enable the steel to work.  The road included a roundabout. The information was issued to us on A4 sheets with string lines relating to various parts of the road.  The road was cast in a hit and miss fashion, each bay being 12m long.

Using our design software we were able to manually input the data on site simplifying what had appeared to be a complicated job.  We were able to check the design by forming contours and viewing the road in 3D.  We would carry out as built surveys at each stage of the construction, producing drawings directly comparing as built position and level to the design.

Buildings

We work on housing estates, small developments as well as large RC frames.  The Laban Centre in Deptford was a pleasure to work on, due to its innovative design and high profile.  A reinforced concrete structure, with sweeping curves, 2 spiral staircases and lots of fair face finish. The London building by Herzog & de Meuron won the 2003 RIBA Stirling Prize

We have also worked on the Radisson SAS hotel at Stanstead where we had to provide ‘as built’ surveys at every stage of construction.  The hotel is a four-storey structure with a floor-to-floor height of 2.9m.

The facade is a curtain wall designed to accept a very low deflection of 8mm at midspan of slabs.  We were responsible for all of the setting out during construction, and also the crushing of the cubes on site.

We provided a 1m level grid, each point was coordinated and superimposed onto Auketts floor plans.  2500 levels per floor per block.

We have also monitored the slabs deflection, to an accuracy of 0.3mm.

Piling

Piles are a pleasure.  Once set out we carry out as builts and can overlay as built and design drawings on site as a double check.  Should obstructions be met we can carry out a quick survey, email it to the engineer from site to enable any necessary changes to be made in real time.

LAND SURVEYS

Site Control

This may consist of permanent markers, retro prisms or the co-ordination of remote observations (ROs).  You tell us the co ordinate system you require and we will match your requirements.
We can rotate grids, provide setting out drawings with numbered points referring to co-ordinate lists, or even uploaded into your instruments with points relating to your drawings.

Volumetric / Cut and Fill

We understand the costs involved in muck away.  Erith Contractors are one of our biggest clients and they expect fast accurate surveys to be carried out to enable them to move on.  Sometimes we may be taking points e.g. Existing piles, whilst they wait to backfill.  We therefore need to process and check the data immediately on site.  No going back to the office, get it done right and get out fast may become our motto.

Boundaries

Relocating existing property boundaries from title deeds or registry plans, or assisting in the definition of new or disputed ones.  We are frequently called on to establish fence lines or wall positions.