Thust Block

[sant007]

I am new to water/wastewater piping.

We are designing 16" sewage Foremain and I was refering to county standards for thurst block and they mention blocing for lower vertical bends and upper vertical bends?

What is difference between lower and upper vertical bends ?

What is difference between Thrust Block/Buttresses and Anchorages...are they same? When to use what

Thanks

Rookie

 

[hydrae]

A thrust block spreads out the force of the bend to the soil, depending upon the thrust and soil strength determines the size of the block in ‘projected area’.

This is not possible for an upper vertical bend as there is not enough soil above the bend to resist the force, as such an anchorage will be required, the anchorage will be in ‘volume’ or weight of concrete needed to resist the force and will also require rebar to transfer the thrust from the fitting to the block which will be below the bend. These blocks are typically larger.

Most locations are switching to restrained joints and there are computer programs available to determine the length of restrained pipe needed to resist the thrust.

Hydrae

 

[rconner]

I wonder if this terminology is referring to what might perhaps be called (for more universal understanding?) a vertical "up bend" and a vertical "downbend", respectively such as would be used on one side of a common vertical pipeline "off-set". Of course, this is readily seen on a profile drawing but maybe not quite so easily understand in email words! If thius is correct I will defer to the good guidance already given by other responders.

 

[ap76]

yes you are correct, this term refers to changes that are visible only on the profile sheet