Optimising storm-water drainage networks
Walters, G. A.
PublisherUniversity of Liverpool
MetadataShow full item record
This thesis examines ways in which the design of storm water drainage networks can be optimised and proposes, develops and tests some such methods. The introduction is followed by a resume of current design practice and an examination of previous work on the drainage optimisation problem. Methods of estimating the construction cost of a drainage network are detailed and functions proposed for modelling these costs. The optimisation problem may logically be split into two areas, namely optimising fixed plan networks and optimising variable plan networks. The former involves the simultaneous selection of gradients and diameters for a network of pipes fixed in plan. A new Dynamic Programming model is proposed for this, having several advantages over previously published methods. The main area of innovation is, however, in optimising variable plan networks. The general plan optimisation problem is seen to be far too complex for solution. However taking the special case of road drainage networks two possible modes of optimisation are defined. These are, firstly, the positioning of an unknown number of manholes along a drain running between two fixed manholes, and secondly, the positioning of an unknown number of cross-drains along a road carriageway. Both modes include the simultaneous choice of pipe gradients and diameters. Models for these modes are proposed, with practical computer programs being developed and tested. Both models use a novel form of Dynamic Programming conceived and developed during this research. The thesis ends with a brief outline of a Dynamic Programming solution to a rather different variable plan problem, followed by suggestions of areas for further study and conclusions of both a specific and a general nature.