Jorge Curiel-Esparza

Human factors engineering in utility tunnel design

Abstract The authors examine human factors engineering in multi-purpose utility tunnels. The smart planning of utility tunnels can take the pain and stress out of the work for employees. The cross-section of these systems must be designed taking in account two space requirements, one for utilities and the other for worker operations. In order to fit the confined workplace environment of a utility tunnel to the employee, some design rules have been proposed. This manuscript shows human factors to be critical design parameters in the design and construction of ‘visitable’ utility tunnels. Human beings cannot be designed, but utility tunnels can.

Criticality and threat analysis on utility tunnels for planning security policies of utilities in urban underground space

A utility tunnel is defined as an underground structure containing one or more utilities, permitting the installation, maintenance and removal of the systems without the necessity of making street cuts or excavations. These underground facilities contain all essential utilities serving large urban areas collected together in a tunnel; therefore they are an inviting target for sabotage or vandalism. This paper proposes an expert system combining color-coded scales, Delphi and AHP methods to analyze criticality and threats on utility tunnels to support planning of security policies for utilities in urban subsurface.

An analysis of utility tunnel viability in urban areas

Urban utilities are overcrowding underground space. Therefore, future sustainable underground strategies will consist of the ability to reduce the use of traditional trenching. During the last century, there was an increasing interest in utility tunnels for urban areas as a problem-solving technique to avoid congestion of the street subsurface. Utility tunnels or utilidors are joint-use underground facilities that may contain multiple utilities such as water, sewerage, gas, electrical power, telephone, and central heating in various combinations or in some cases all together. The key advantage of utilidors is the substantially lower environmental impact when compared with trenching alternatives. Their construction presents no new problems of an engineering nature. However, implementing these subsurface tunnels is retarded most by first-cost, compatibility, and liability problems. These underground facilities are highly complex and difficult to manage because of synergistic effects. Utility tunnels, as a major capital investment in urban development, should be considered in the broad context of the urban planning strategy. This research work has focused on utility tunnel feasibility and its practical application in urban areas.

Hybrid method for selection of the optimal process of leachate treatment in waste treatment and valorization plants or landfills

Leachate from waste landfill or treatment plants is a very complex and highly contaminated liquid effluent. In its composition, it is found dissolved organic matter, inorganic salts, heavy metals, and other xenobiotic organic compounds, so it can be toxic, carcinogenic, and capable of inducing a potential risk to biota and humans. European law does not allow such leachate to leave the premises without being depolluted. There are many procedures that enable debugging, always combining different techniques. Choosing the best method to use in each case is a complex decision, as it depends on many tangible and intangible factors that must be weighed to achieve a balance between technical, cost, and environmental sustainability. It is presenting a hybrid method for choosing the optimal combination of techniques to apply in each case, by combining a multicriteria hierarchical analysis based on expert data obtained by the Delphi method with an analysis by the method of VIKOR to reach a consensus solution.

Understanding the major drivers for implementation of municipal sustainable policies in underground space

Because of the expanding population in our cities with its demands for more diversified services, we cannot afford a piecemeal type of urban underground growth. Utilization of the urban street system for buried utilities has a serious adverse effect on other street functions because of the continuing necessity to perform excavations for the repair of existing lines and the installation of new ones. The excavations not only are a serious cause of traffic delay and congestion but also create noise and aesthetic disturbances, and result in excessive street maintenance requirements and in shortened overall street life. Consider the enhancing effects in quietness on abutting properties and users of the street, and the benefits become very great. Unfortunately, the lack of data and the difficulty in quantifying the intangibles have made it impossible to arrive at a reasonably accurate figure of overall negative impact on the urban environment of street cuts. However, if drivers are sufficiently strong to merit the use of utility tunnels, then sustainable municipal policies improving living quality will be implemented.

Optimal infrastructure selection to boost regional sustainable economy

The role of infrastructures in boosting the economic growth of the regions is widely recognized. In many cases, an infrastructure is selected by subjective reasons. Selection of the optimal infrastructure for sustainable economic development of a region should be based on objective and founded reasons, not only economical, but also environmental and social. In this paper is developed such selection through a hybrid method based on Delphi, analytical hierarchy process (AHP), and VIKOR (from Serbian, VIseKriterijumska Optimizacija I Kompromisno Resenje). To do this, a panel of experts assesses both the infrastructures and the drivers for their selection. The method lets us to verify the consistency of answers from experts. In our case, AHP obtains preference values for each infrastructure using the eigenvector method. Meanwhile, the VIKOR method evaluates whether the proposed is the one that best fits the prevailing view, minimizing the regret to the most separate opinions. Thus, for La Costera (Spain), the region under study, this research work concludes that the thematic route is the optimal infrastructure.

Integrating climate change criteria in reforestation projects using a hybrid decision-support system

The selection of appropriate species in a reforestation project has always been a complex decision-making problem in which, due mostly to government policies and other stakeholders, not only economic criteria but also other environmental issues interact. Climate change has not usually been taken into account in traditional reforestation decision-making strategies and management procedures. Moreover, there is a lack of agreement on the percentage of each one of the species in reforestation planning, which is usually calculated in a discretionary way. In this context, an effective multicriteria technique has been developed in order to improve the process of selecting species for reforestation in the Mediterranean region of Spain. A hybrid Delphi-AHP methodology is proposed, which includes a consistency analysis in order to reduce random choices. As a result, this technique provides an optimal percentage distribution of the appropriate species to be used in reforestation planning. The highest values of the weight given for each subcriteria corresponded to FR (fire forest response) and PR (pests and diseases risk), because of the increasing importance of the impact of climate change in the forest. However, CB (conservation of biodiversitiy) was in the third position in line with the aim of reforestation. Therefore, the most suitable species were Quercus faginea (19.75%) and Quercus ilex (19.35%), which offer a good balance between all the factors affecting the success and viability of reforestation.