Journal of Infrastructure Systems

A methodology is developed for the design of an automatic gate controller for an on-demand canal system. The design is based on the EL-FLO plus RESET control concept developed previously by the U.S. Bureau of Reclamation. Two additional design parameters are included in this study to ensure a smooth upstream gate operation. The basic design parameters are optimized to achieve a stable flow condition in the entire canal system where multiple gates are operated to supply water to meet unexpected turnout demands along the canal. Due to the complexity involved in canal hydraulics, the optimization model is highly nonlinear. Decomposition allied with successive approximations is used for solution. The proposed design methodology, when applied to a section of the Caraibas Project in northeastern Brazil, showed that the proposed methodology is successful in minimizing hydraulic transients in a multipool canal system. A sensitivity analysis of the optimal design is conducted with respect to maximum demand level and the two new design parameters.

The U.S. inland navigation infrastructure is deteriorating primarily due to the aging of its components and the operation at near to full capacity of the system's structures. Gates at navigation locks play an integral part in keeping navigation traffic continuously moving, and their reliability is essential to the navigation infrastructure. Assessments of fatigue reliability as a function of time for existing gates at navigation locks require knowledge of loading cycles. This assessment can contribute to the economic evaluation of the remaining fatigue life of critical fatigue details in gates. The accuracy of this assessment depends in part on the accuracy of the loading cycles used in the reliability analysis. Water elevations from hydraulic records were used to compute water-head differentials on the miter gates. Loading or hardware cycles were obtained from the U.S. Army Corps of Engineers (USACE) lock performance monitoring system (LPMS), and were then combined with head differential to obtain loading histograms for the gates. These histograms are needed to successfully perform fatigue reliability analyses. A probabilistic model was also developed for predicting the number of loading or hardware cycles for the gates. This paper includes an example to demonstrate the suggested methods and models for fatigue reliability assessment.

Fine-particle transport in porous media affects performance of civil infrastructure in a number of diverse disciplines. The particle transport processes that are important in infrastructure systems are (1) wastewater filtration; (2) clogging of soil and geotextile filters used as liners for protection of subsurface and aboveground structures; (3) erosion and piping in earth dams; and (4) facilitated transport of contaminants in the subsurface. While particle release from soils is the primary focus in some areas, their transport and subsequent entrapment are important in others. In this paper, research developments on particle transport are reviewed in each of these areas and the cross-cutting nature of the fine-particle transport problem is demonstrated. The need for synthesis of research developments in the individual areas is assessed considering the emerging developments in geoenvironmental engineering. The challenges associated with integrating the research developments are pointed out.

The U.S. Army maintains more than 200 installations within the 50 states and another 95 overseas. However, money has been shifted from maintenance of facilities on these installations to training and the support of operations such as those currently under way in Bosnia. Some estimates are that there will be in excess of $5.1 billion in backlogged repair and maintenance projects on U.S. Army installations by the end of fiscal year 1997. Thus, the Installation Status Report (ISR) was developed to categorize installation facilities that were deficient, develop funding requests for Congress, and to allow the installations to better articulate their needs to the Department of the Army (DA). ISR results are used to provide a nontechnical evaluation of current installation readiness. This is significant in that it was developed to help policymakers to understand the status of the installations. The ISR has proven to be a major success. The DA has been able to use ISR to articulate the needs and costs to Congress, which has directly led to additional funding in critical areas such as family housing. This paper is written to present the ISR to civil engineers outside the military facilities management area. A system similar to ISR should have application for assessing the condition and estimating funding requirements for operation and maintenance of any large infrastructure system such as universities, cities, school districts, etc., and will also be discussed.