Benefits of EARLY excavation assessment
Many developments require a flat, level platform to build on. This may be because equipment is designed for level operation, or, it might create a safer environment for construction/operational requirements.
It is acceptable practice to try and create a BALANCED platform where the excavated cut material is used to provide the fill material creating the required BALANCE thus negating the need for costly transportation of material on or off site.
Envsupport Volume Reporting
It is very unlikely that a flat/level area of ground will be found that matches exactly the dimensions of your development so when assessing the suitability of each site option it would be useful to have the data to show what impact each site excavation will have.
An important part of ENVsupport’s services is the ability to provide, quickly and easily, VOLUME REPORTS for specific platforms that are under consideration at the optioneering phase of site selection. >>>>>
Volume Reporting as part of Site Selection (and determining Platform Levels)
Site levels, excavation footprints and how much material requires to be moved can play a large part in whether a site is suitable. Costs of excavation, amount of material to be transported to and from site, resultant platform levels (with respect to visibility analysis) are all factors that could influence site suitability.
By determining these factors early, differences between sites become quantifiable and therefore more easily rated in a site scoring exercise.
Example
In the example shown, platforms A, B, C, & D all have identical rectangular platform footprints. They have been positioned in site options that, initially, appear to accommodate the platform size and the platform level has been set to achieve an equal cut & fill balanced excavation.
When excavation batters have been applied we see that the footprint size increases and volumes vary between options.
To give a practical perspective on this difference in volumes, we see the that A & B differ by a quantity of 110,024m3. If excavating in rock option B would cost £5.5 million MORE than option A, and, if moving the excavated material, would require an ADDITIONAL 11,000 lorry loads (22,000 trips to & from site).
Excavating ADDITIONAL material for Screening Bunds
When trying to screen a development using raised earth bunding, the additional material required would be best obtained from the excavation of the site.
This method negates the need to transport material onsite (which can be costly) and also increase traffic flow in the local community which may be used as an objection to planning consent.
An obvious downside to using onsite material is that any extra material excavated for bunding can have an effect on the final platform level as well as increasing cost of excavation.
Example
STEP 1) Bund Volume Requirement
The example below shows a proposed screening bund with an approximate volume of 40722m3.
STEP 2) Original Platform Level
We can show that to achieve a development platform that is balanced (equal cut & fill) it would have to sit at a level of 83.40m
We can see from the VOLUME REPORT for level 83.40m that the CUT volume (1) and the FILL volume (2) are almost the same leaving a negligible (i.e. balanced) NET volume (3).
STEP 3) Revised Platform Level
To gain enough ADDITIONAL material to construct the proposed screening bund we have to lower the level of the platform to 82.63m
We can see from the VOLUME REPORT for level 82.63m that the CUT volume (1) MINUS the FILL volume (2) gives an additional overburden of material (3) which is approximately the amount required to construct the proposed screening bund.
By analysing the volumetrics of the site, contingency for later screening can be included in the early design which will vastly reduce subsequent design changes.
Having a more fixed early design also provides a clearer base line for all team members working on the project where changes can be more controlled. Being able to produce this additional, easy to understand, supporting documentation in your Environmental Assessments will not only demonstrate to your client, an attention to detail, but will also remove guesswork and assumptions from you evaluations.
If you are interested in finding out more about this feature please get in touch via email or phone for an informal chat…?
Sections
Using the facilities above, Project Managers can accelerate early optioneering decisions by quantifying the differences between site options. Having a better visibility and understanding of previously unknown costs, they can also evaluate if there are any other hidden factors that could influence scoring of site suitability, such as additional forestry clearance, feasible access tracks, encroachment into land owners property etc.
Please feel free to Contact Us for more information and support.
Longitudinal Sections
Once you have created a 3D Model of your development, and by using the Ordnance Survey (O.S.) level data, that makes up the terrain model, it is possible to automatically create multiple sections across any line drawn on the site easily and quickly by simply feeding in a few required survey parameters.
These sections can be analysed and used to emphasis civil engineering impact or highlight areas of concern, for instance, showing platform level compared to bunding height or analysing the cut and fill slope batters on an excavated platform
Ground sections of the chosen design, can allow Civils Consultants to prepare a more substantial practical evaluation of construction issues.
These sections can be used by Landscape Architects to assess aesthetic compatibility of bunding shape against existing ground topography.
or a longitudinal section on a multi-kilometre cable or overhead line route could identify where gradients were unsuitable for construction or installation…?. Something that wouldn’t be as clear on a 2D only document.
Where optioneering is taking place, resultant data could be made available to civil engineering consultants as a basis for upfront budget costs without having to have costly detailed surveys done at this stage.
Cross Sections
Once the 3D model has been created, multiple cross sections can be generated quickly and easily by inputting a few key parameters.
These can be made available to Civils Consultants for evaluation or used as supplementary information in site justification reports.
These sections can be used by Landscape Architects to assess aesthetic compatibility of bunding shape against existing ground topography, or, allow Civil Engineers to highlight potential issues with the design.