GBBSoft - Software for designing bank and bed protection for inland waterways
The ordinance issued on September 16, 2008 introduced the GBBSoft software for designing bank and bed protection for inland waterways in the scope of business of the WSV for application cases not covered by standard building methods.
GBBSoft contains the calculation methods and design concepts featured in newsletter No. 88 'Principles for the Design of Bank and Bottom Protection for Inland Waterways' issued by the BAW in 2005. This presents a new more general design concept offering solutions for conditions that deviate from the standard situation. Since 2011 a comprehensively revised and updated version of the GBB is available
The software GBBSoft is intended to serve the following purposes:
- simplifying the application of GBB procedures and reducing the time needed for calculations, particularly when searching for optimum solutions
- making the application of GBB more reliable by helping to avoid misunderstandings and computing errors when using what in some cases are highly complex algorithms, and
- avoiding the duplication involved when every user starts programming GBB algorithms which are iterative in some cases.
GBBSoft ascertains the loading on banks resulting from the primary and secondary wave field of typical inland navigation vessels (e.g. motorized freight vessels, pushed barge units, sport boats) in stationary movement parallel to the banks in a prismatic, trapezoidal cross-section through the waterway. Loading on the beds and banks resulting from the propeller wash of the main drive and a bow-thruster (propulsion-induced loading) can be calculated for manoeuvre situations (negligible vessel speed) for any jet direction.
GBBSoft takes ship-induced loading such as return current and slope supply flow as well as the propeller wash and stern wave height to calculate the necessary size of individual stones in loose rip-rap to avoid or at least extensively limit surface erosion of rip-rap stones. This dimensioning task is called "hydraulic design".
"Geotechnical design" refers to the necessary rip-rap thickness to warrant local stability (avoiding slides in a sliding surface near the bank and of hydrodynamic soil displacement respectively). Global stability (considering a deep sliding surface) is not verified. Various rip-rap supports can be chosen to improve stability, such as an embedded toe or a toe blanket. Here for example the depth of the embedded toe is varied automatically to make it easier for the user to ascertain the optimum rip-rap design.