Benchmarks

Just curious, does anyone know how often the benchmarks used for levelling are updated, or are they?

godtabh

permanent bench marks wouldn't be updated that often where is temporary ones would be every couple of months.

I think!

themole

I would think never.

Thats why they are benchmarks. so they can be used as as reference point

godtabh

themole wrote:

I would think never.

Thats why they are benchmarks. so they can be used as as reference point

There is a difference between temporary benchmarks and permanent benchmarks.

themole

By my understanding of the term benchmark is a point of reference. You never change the point of reference.

In relation to civil engineering, which i believe the word if being used here, then this still holds. The benchmark in this case is one on ie a building. These are not updated, bar some freak subsiding of the building. Thats why they are used.

If you are talking about some temporary point being used for example within a building site, then this is not a benchmark as it is not permanent.

Now, in the civil engineering world they may indeed use the term "temporary benchmark", but that doesn't really make sense to me. I am however not a civil engineer, so that term may well be used.

godtabh

themole wrote:

By my understanding of the term benchmark is a point of reference. You never change the point of reference.

In relation to civil engineering, which i believe the word if being used here, then this still holds. The benchmark in this case is one on ie a building. These are not updated, bar some freak subsiding of the building. Thats why they are used.

If you are talking about some temporary point being used for example within a building site, then this is not a benchmark as it is not permanent.

Now, in the civil engineering world they may indeed use the term "temporary benchmark", but that doesn't really make sense to me. I am however not a civil engineer, so that term may well be used.

The temporary bench marj would be used on site to set out buildins/roads/bridges tec and would be referenced from a permanent benchmark.

The reason why its temporary is that its would be only used for the life time of that job.

themole

kearnsr wrote:

The temporary bench marj would be used on site to set out buildins/roads/bridges tec and would be referenced from a permanent benchmark.

The reason why its temporary is that its would be only used for the life time of that job.

I hear ya.

But in that case it would be more precise to call it a temporary reference point.

To me at least the word benchmark implies permanence, so i wouldn't use the word benchmark when talking about something temporary. So, i know what you mean by "temporary benchmark", what i would say it thats not the right phrase to use.

Voodu Child

themole wrote:

But in that case it would be more precise to call it a temporary reference point.

To me at least the word benchmark implies permanence, so i wouldn't use the word benchmark when talking about something temporary. So, i know what you mean by "temporary benchmark", what i would say it thats not the right phrase to use.

Nah. You'll record it in your level book as a TBM. Its a benchmark if you're using it for a reasonable duration of the project, permanent or not.

We came across an old benchmark buried under grass up in the airport. Probably something historical....ripped it right up and threw it in a skip

Sundy

Myth wrote:

Just curious, does anyone know how often the benchmarks used for levelling are updated, or are they?

They are not up-dated and are now offically redundant. The osi has decided to no longer support the benchmarks. Most of them are still ok though, but if you want to be sure of it, do a loop between two benchmarks to check them.


Oh and tempory benchmark or TBM is the correct term