Investments in infrastructure are mainly provided by the public sector and represent, together with the running cost of existing infrastructure, a significant proportion of public budgets. A challenge facing every state is maintaining its infrastructure in a good state of repair to support optimization of economic activities and meet relevant environmental regulations, while at the same time having sufficient funds available for supporting new growth.
However, reducing maintenance costs and improving wastewater and water systems' efficiency have always been challenges for municipalities and decision-makers due to the large number of factors involved (i.e. volume, velocity, temperature and chemical composition of the waste stream, burial depth, diameter, and material composition of the pipe; multiple failure modes/patterns). The traditional approach for rehabilitating an inadequate sewer or water system is replacement using the open cut method. In congested and densely populated areas, performing such an operation would disrupt traffic and nearby businesses and result in annoyances (noise, dust, vibration) to the general public. Additional costs may be associated with the repair and repavement of the road surface or landscape features as well as accelerated deterioration of secondary roads due to detours and in some cases reduced road safety. In the past few decades new methods, namely Trenchless Technologies, have been introduced to the municipal marketplaces that are capable of rehabilitation, replacement and new installation of buried sewer and water pipes with minimal surface disruption and potentially, lower costs.
With this in mind, the research team, along with its sponsors, set out to develop comprehensive, yet straightforward and easy to use interactive software for the evaluation and ranking of alternative construction methods that can be employed in the installation, rehabilitation or replacement of buried sewer and water pipes. The need for a computerized decision support system arose from the following reasons:
|Number of Technologies: || 20 Trenchless and 2 Open-Cut methods for the installation of new pipes
6 Inline Replacement methods for replacing exisitng pipes
34 Trenchless rehabiliation methods for restoring existing water and wastewater pipes as well as laterals
18 methods for restoring and/or replacing existing manholes
|Complexity of Analysis: || Each alternative construction method offers unique advantages and limitations; also,
the decision making process involves a large number of parameters, some of which are interrelated
| Rapid Development Methods: || Decision-makers that are not well acquainted with recent developments in the rapidly growing field of trenchless technology will not be aware of methods that can accomplish the same task with less disruption and at lower costs than traditional open-cut methods.