|
HydroCAD® Stormwater Modeling - Since 1986
|
Software Status Bulletin # 115Subject: Incorrect displacement for "milk crate" stormwater chambersApplies to: HydroCAD 8.5 to 9.1 build 21DescriptionWhen certain "milk crate" stormwater chambers are embedded in stone or sand, the displaced volume is understated by 2%-8%, depending on the specific chamber. This causes a slightly larger amount of backfill to be calculated, with a corresponding increase in the total system storage. ExplanationThe affected chamber definitions did not allow for the volume of the structural members when calculating the displaced volume. However, the internal volume correctly allowed for the plastic structure, so non-embedded storage calculations are not affected by this issue. Since "milk crate" type chamber installations usually do not make use of storage in the backfill, this issue will have no effect on most installations. The effect is see primarily when using the chamber wizard, since it will indicate stone fill in the volume that is actually occupied by the structural members. RecommendationOwners of HydroCAD 8.5 through 9.1 should download and install the latest chamber update. CommentsThis problem is corrected in HydroCAD 9.1 build 22. Owner's of HydroCAD 9.1 can download the latest build using their original 9.1 download details. Technical DetailsThe following chamber definitions are affected by this issue:
|
|