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An improved steel sheet pile (SSP) inspection procedure is proposed in this paper, which couples the field inspection condition-index methodology previously developed by the U.S. Army Corps of Engineers with reliability assessments to quantify the life-cycle costs and environmental impacts associated with various maintenance and repair (M&R) scenarios. Maintenance and repair strategies over the analysis period (from present to the end of the structure's lifetime) are determined through reliability assessment for structures with relatively low condition indices. The level of maintenance activity is then to be determined by the life-cycle cost analysis and environmental life-cycle assessment of M&R alternatives. The optimal M&R alternative is the one with the lowest cost combined with minimal environmental impact. Using these methodologies, the SSP structure owners will gain improved capabilities to monitor present-day conditions of SSP infrastructure and prioritize structures that will require sustainable M&R. Further research is proposed to collect real field-inspection data and create M&R records that can be used to estimate the reliability more accurately. In addition, the methodology developed for this relatively simple type of structure can be extended to more complex and critical structural systems such as gates, valves, and other components making up locks, dams, and other related navigational facilities. [ABSTRACT FROM AUTHOR]

This paper examines environmental impact, costs, and social impacts comparing four construction techniques commonly used in the installation of underground utility infrastructure. The three impact factors are quantified to develop an overall underground sustainability index rating (USIR) for evaluating utility projects with competing installation technologies. The main contribution to the overall body of knowledge is the demonstration of a method for calculating a sustainability index that enables decision makers to quantify public works utility projects with guidance for evaluating proposed technologies based on environmental impact, costs, and social impact criteria. The aim is to help change the myopic thought process of typical public works owners who typically base contractor selection on lowest cost, rather than examining sustainability factors. An emission calculator was used in this research to quantify environmental impact by comparing six airborne emissions: carbon dioxide (), carbon monoxide (CO), particulate matter (PM), nitrogen oxide (), sulfur oxide (), and hydrocarbons (HC). Costs were determined by estimating competing technology options including surface restoration. Social impacts were quantified by comparing and rating 13 factors affecting underground utility projects. The approach to calculating the USIR was demonstrated on a case study installation of 313 m (1,026 linear feet) of 400 mm (16 in.) PVC sanitary sewer in a mature neighborhood in Portland, Oregon. The USIRs were compared for open-cut, pilot tube microtunneling, horizontal directional drilling, and vacuum microtunneling technology options. [ABSTRACT FROM AUTHOR]

Building regulations and governmental policies create pressure on the construction industry to minimize the environmental impacts that are caused by buildings. Achieving energy efficiency, and thereby low-carbon construction, is only possible by cooperation among the participants in the construction supply chain. Clients in particular have an important role in promoting environmental sustainability. In this paper, the carbon-reduction process is analyzed from a construction client's perspective. A framework is developed to analyze the interrelated components of this process, including the drivers, initiatives, challenges, facilitators, solutions, and achievements. A qualitative case study methodology was employed to gain a better understanding of the project-based practices and corporate policies in achieving energy efficiency. The study presents the results of three award-winning construction projects from the U.K. in which innovations for improving environmental sustainability were based on the Code for Sustainable Homes. The study outlines the initiatives and strategies of clients for carbon reduction, obstacles faced by project teams, mechanisms that helped overcome the difficulties, and low-carbon solutions applied to design, construction, and operation in the selected cases. Effective leadership, corporate responsibility, a focus on end users, repeatable nature of projects, and integrated teams are found to be the main success factors. The findings of this study are expected to guide construction professionals in implementing innovative low-carbon practices in collaborative project environments. The proposed framework can be used to better understand the carbon-reduction process in other projects and other countries where different regulations and conditions prevail. [ABSTRACT FROM AUTHOR]