eDNA Study of the Kellogg-Mt. Scott Watershed

The Kellogg Creek Restoration and Community Enhancement Project is an exciting effort occurring in the heart of downtown Milwaukie. The project encompasses many elements, including: providing fish passage to 15 miles of habitat by removing the barrier at Kellogg Dam restoring 17 acres of high-quality habitat behind the dam providing public access and viewing points to encourage nature-based recreation and outdoor education increasing flood storage capacity to reduce flooding in lower Kellogg Creek modernizing the existing Oregon State Highway 99E bridge with an alternative that increases seismic resiliency and establishes a safe bike/pedestrian undercrossing providing interactive learning, scientific research and real-world laboratory opportunities for student involvement and community science engaging the community through cross-cultural communication tools and events As a part of the pre-project research, the North Clackamas Watersheds Council conducted an eDNA study to better understand fish access past the dam and look at seasonal and geographic utilization of the watershed by salmonids and Pacific lamprey. We also looked for the presence of western pond and watershed painted turtles in the impoundment. This information will provide pre-construction baseline data, and help inform the Council\u27s protection and restoration efforts throughout the watershed. Collection of eDNA is noninvasive and biological information can be obtained without handling organisms and disturbing their ecosystems. It is also a new and innovative tool in urban environments where private properties are small and permission to access multiple properties would be necessary for biological surveys such as snorkeling and electrofishing

In situ elevated temperature testing of fly ash based geopolymer composites

In situ elevated temperature investigations using fly ash based geopolymers filled with alumina aggregate were undertaken. Compressive strength and short term creep tests were carried out to determine the onset temperature of viscous flow. Fire testing using the standard cellulose curve was performed. Applying a load to the specimen as the temperature increased reduced the temperature at which viscous flow occurred (compared to test methods with no applied stress). Compressive strength increased at the elevated temperature and is attributed to viscous flow and sintering forming a more compact microstructure. The addition of alumina aggregate and reduction of water content reduced the thermal conductivity. This led to the earlier onset and shorter dehydration plateau duration times. However, crack formation was reduced and is attributed to smaller thermal gradients across the fire test specimen

Looking back to guide us on how to move forward for geopolymers

Making geopolymers and alkali activated materials with specific properties requires skill and a thorough understanding of the process. The trial and error approach used by many researchers may result in an acceptable product but there is little or no understanding of why it worked and how to improve or optimise the product. It also leaves potential producers without quality control of feedstock hence limited quality assurance on product. This presentation will look back at how the geopolymer group at Curtin University improved its understanding of geopolymer technology via development of XRD, SEM and related analytical techniques. Examples on how geopolymers were made with very high compressive strength on one hand and on the other hand with impressive fire resistance will be described. However, this is not the end of the story. Ultimately the goal is to commercialise geopolymers and for this to happen we must conduct rigorous life cycle analysis and embodied energy assessments to be confident that these materials are competitive and sustainable. One way to ensure low embodied energy is to explore alternate activators and sources of alumina and silica. When alternate precursors such as Bayer liquor have been used to manufacture geopolymers they prove to have a very low embodied energy and are potentially less expensive. The use of Bayer liquor for geopolymers will be described in detail and examples provided on how this approach may be viewed as a way forward for the field of geopolymers for specific products

Surcharge Fill and Vertical Drain System Improves Soft Clay Site

The Intermountain Power Project in Delta, Utah required construction of a Railcar Service Center near Provo, Utah. Preliminary investigations related to the design of the proposed facility revealed the presence of soft clays at the site adjacent to the foothills of the Wasatch Mountains. Detailed geotechnical laboratory and field investigations were performed using relatively undisturbed California samples, thin-walled Shelby tube samples, and cone penetration test soundings. The detailed investigations revealed the presence of a significant layer of deep, soft varved clay. This soft clay layer originated from alluvial deposits from the old Lake Bonneville. Because of the need to develop the site to substantially higher final grade elevation, which in turn necessitated the placement of supplemental fill material, the project team decided to use a preload/surcharge fill (comprised of soil to be used in the ultimate site development) and prefabricated vertical drain system designed to mitigate long term settlements for the facility. The impetus for adopting this design approach was to use shallow foundation systems for the project, as opposed to a more expensive foundation system consisting of driven pile foundations. The designers used two basic approaches to the ultimate development of the site as impacted by the underlying soft, compressible varved clay. 1. Laboratory triaxial strength testing and cone penetration test (CPT) sounding were used to develop a site-specific shear strength profile. 2. One-dimensional consolidation testing, including time rate analyses, was used to define a past pre-consolidation confining pressures and the anticipated virgin compression parameters. The overall preload system design accounted for the rate of fill installation, global stability of the fill/natural soil profile, and anticipated internal drainage conditions of the varved clay. Design predictions related to magnitude, rate and duration of the preload settlement are compared with actual settlement measurements of the fill and deeper, intermediate strata within the varved clay. The magnitude of settlement related to the surcharge fill approached 7 inches. An ancillary and coincident activity related to the preload activities included the performance and interpretation of a pile load test installed into the varved clay profile. The strength profile developed for project design is also used to analyze the load transfer mechanisms during the pile load test, which also provided an understanding of the ultimate pile capacity as defined by the load test