New Software upgrade for Mickey in June 2024

Usually, our customers ask me how to design a manhole and the question of the used standards. The manhole is an underground service access structure, which can access gravity pipelines (the design is not made for landfills, because the load behaviour is different.). Here I want to present the American Standard ASTM-F1759 “Standard Practice for Design of High-Density Polyethylene (HDPE) Manholes for Subsurface Applications. The standard will provide the basic procedure related to the design (profile / dimension) of the manhole barrel / vertical riser / shaft. Always a third-party should re-check the design values (especially to add maybe needed safety factors), but for a quick design the results are suitable. The design result is always a CPR-profile, which means a solid homogenous inner layer (waterway), a profile in the middle and a top cover solid layer. Open profiles should not be used, like PR-profiles. The Inlet/Outlet should be jointed my extrusion welding and the shaft my integrated electro-fusion jointing (to extend over 6m / 20’). The manhole cone (e.g. a concrete ring, with a standard cover) and manhole base / bottom (with protection against groundwater) can have several designs.

• The considered loads are:
• The Subsurface Loading in the Manhole (Riser, shaft)
• Radial Pressure
• Downdrag (Axial Shear Stress)
• Groundwater effects
• Live loads
• Installation and bedding conditions

Other parts of the manholes are not part of this (but the software will continuously be updated). Other parts could be manhole ladders, manhole lifting lugs, anti-floating devices.
Now, a new trial upgrade in Mickey will easy the design (or basically finding the lightest profile for an installation condition). The idea is to be able to provide a quick and easy structural calculation, with a weight optimized Krah-profile.

Dr. Alexander Krah / CEO Krah GmbH