Batter

I have a cistern excavation to calculate. The excavation has to go down to a level of -3ft below grade and I then have to place 12" of fill in the bottom of the pit. How do I establish a zero batter for the cut and fill. If I simply change the batters for the cut and fill to zero a red border pops up around the respective boxes, which I assume means there is an error.

Why is there no batter? - because firstly the Contractor will not get paid for over dig and we've agreed a rate on that basis. Secondly the ground is very stable, meaning that there's very little risk of collapse, hence the reason why the contractor will not get paid for over digging the size of the pit needed.


Thanks

Kevin

Hi Kevin,

You are correct that the red box indicates that the software isn't happy with the value you have typed.  If you get this problem you can hover over the box and a tool-tip should appear telling you what it is that the software doesn't like.  For the batter angles you can go to a steepest batter angle of 1:0.01 which is about 0.5° from vertical.

Now the obvious question is why you can't you type in a batter of zero, which as you say should give the vertical slope that you want.

The straightforward answer is that Kubla Cubed doesn't currently support totally vertical slopes.  There are various technical reasons which are related to the triangular prism calculation engine we use to calculate volumes.  This is the most accurate way to calculate earthworks volumes, but also throws up quite a range of technical challenges for our programmers that simpler methods don't have.

...And to be honest, we've never prioritised resolving this issue before now, because we've never come across an example where very steep slopes aren't good enough in practice.

However, as it happens we have recently been doing R&D into allowing vertical slopes, because I think it is difficult for users to understand why they can't do this.  Our principle has always been to make this software as intuitive as possible, so we're working of fixing this and I believe vertical slopes will be possible in an update this year.

Leo