Optimal sewer network design using UTOPIA: Modifications in geometry and mass criteria of the current methodology

Abstract

This paper proposes a series of possible modifications to the methodology for the layout selection of an urban drainage system proposed by Saldarriaga, Zambrano, Herrán, & Iglesias-Rey. These modifications focus uniquely in the method they propose to determine the initial layout network, that is, the objective function that intends to generate a first approximation of the network's layout by modelling the land topography. The contribution of this paper in that research is the development of new criteria to define that initial layout. In this way, first, new ways of handling and combining topographic and topologic data (geometric information) are derived. Second, the inclusion of dissipated energy (energy in the form of mass) is introduced by considering the manhole inflows. Finally, a conjunction of the previous contributions (geometry and mass criteria) is used to define new criteria and observe their combined performance. These new criteria were tested in eight case studies: five slope variations of the Chicó sewer network proposed by Duque et al. and three other networks (Li and Matthew's, Moeini and Afshar's and Tunja's). The test of these changes in all of the case studies generated satisfactory results, succeeding to lower the construction cost of each network. These tests leaded to other conclusions, including: 1) there is not a unique criterion that generates the best result in all the scenarios; 2) the best criteria set depend on the topographic configuration of the network; 3) cost reductions are most significant in steeper topographies; 4) the inclusion of dissipated power generated outstanding results, among others.