Fatigue Testing of Cables – Issues and Lessons Learned

<p>Pedestrian bridge design is becoming more demanding and challenging as architects create new ways to experience bridges. This is particularly evident in the design of cable supported pedestrian structures.</p><p>Innovative and creative concepts require a higher level of fatigue testing to verify cable systems meet design demands and reach service design life.</p><p>The Scioto River Pedestrian Bridge is one such example of innovative pedestrian bridge design. The structure is a suspension bridge with a non-redundant main cable system. Cable supported pedestrian bridges have demonstrated a proclivity for fatigue issues in the past. To address this concern, refined fatigue testing requirements were developed which were intended to verify that the cable system and manufacturing quality control were fit for the unique structure demands. The lessons learned through the process of design, testing, and construction of the cables on this project are useful tools for teams seeking to successfully deliver future cable supported bridge projects.</p>

First Records of Freckled Madtom (Noturus nocturnus) in Ohio, USA

Two new Ohio localities for the Freckled Madtom (Noturus nocturnus Jordan and Gilbert, 1886) were recently discovered. These are the first, and currently only, Freckled Madtom collected in Ohio waters. A single individual was collected in the Scioto River in Scioto County by the Midwest Biodiversity Institute (MBI) and a previously misidentified specimen was collected in the Ohio River at the Hannibal Locks and Dam by the Ohio River Valley Water Sanitation Commission (ORSANCO). The closest historical records are from the Little Sandy River and Big Sandy River drainages in eastern Kentucky. Other Ohio River collections have been made near the border of Kentucky and Indiana. The origins of the recent Ohio specimens are unknown; whether they emanate from other known populations or have been overlooked altogether is unclear.

From Catastrophe to Recovery: Stories of Fishery Management Success

<i>Abstract</i>.—A 37-year series of standardized fish assessments in the Scioto River (Ohio, USA) since 1979 coupled with historical information documents a near complete recovery from heavily polluted conditions in the late 19th and early to mid-20th centuries. Nearly 100 fish species were extirpated downstream from the city of Columbus (Ohio, USA) by sewage and industrial pollution. The 1972 amendments to the Federal Water Pollution Control Act (Clean Water Act) mandated the control of sewage and industrial pollution. Reductions in loadings of untreated or poorly treated sewage were incremental. Full recovery to near-prepollution composition and abundance took more than two decades after advanced wastewater treatment was achieved. Unpolluted tributaries served as recolonization sources for populations of extirpated species. These positive changes extended across all fish assemblage members as evidenced by increased values of the Ohio index of biotic integrity; modified index of well-being; native species richness, density, and biomass; and the reduced incidence of external anomalies on fish. These restoration successes and their documentation were facilitated by the Clean Water Act that set forth the goals for water quality standards and treatment technology for reducing water pollution and conducting baseline and follow-up monitoring. An important lesson learned was that serious doubts that existed in the 1970s about the feasibility of advanced wastewater treatment technology and the attainability of water quality standards in an effluent dominated river were completely erased by the demonstrated improvements in the fish and macroinvertebrate assemblages in the Scioto River. The extent of improvements in recreational opportunities have tracked that of the biota by an increased use for fishing, canoeing, kayaking, and related forms of recreation. However, maintaining these improvements will require continuation of high levels of wastewater treatment and water quality standards. A growing human population that is forecast to increase by one-half million persons by 2050 makes maintaining the currently high levels of biological integrity a continuing challenge. Given the lessons learned with the mosaic of stressors in the Scioto River over the past 150 years, we believe this challenge can be met successfully.

The Distribution and Abundance of mussels (Bivalvia: Unionidae) in Lower Big Walnut Creek from Hoover Dam to its Mouth, in Franklin and Pickaway Counties, Ohio

Big Walnut Creek in central Ohio once supported a mussel fauna of 40 species, but no systematic study of the mussels of the creek has been done. The objective of the current study was to determine the distribution and abundance of mussels in Big Walnut Creek downstream of Hoover Dam (RM 36.7) to its mouth with the Scioto River. The extant (living and freshly dead shells) and total (extant plus weathered and subfossil shells) mussel communities were determined at 21 sites. Two techniques were used to determine the mussel community at each site: timed searches and transect/quadrat sampling. Shannon-Weiner (H’) values, Jaccard Coefficient of similarity values, and percent extant species were calculated for the mussel communities at each location. Student T-tests were used to determine where either a significant change in community structure occurred based on the metrics listed above. The mussel communities from Hoover Dam to Whitehall (RM 22.0) had maintained their diversity. The historic and extant communities in this reach were essentially the same (Jaccard Coefficient = 83% and percent extant species = 78%) with H’ values for this reach not significantly different when comparing the total and extant communities (t = 1.08, p > 0.05). The communities from RM 22.0 to RM 15.0 (just downstream of Three Rivers MetroPark) had fewer extant species (Jaccard Coefficient and percent extant values of 62% and 36%, respectively), and significantly diminished species diversity (t = 2.35, p < 0.05). Diminished species diversity continued to be expressed downstream (t = 2.48, p < 0.05), with some recovery (Jaccard Coefficient = 67% and percent extant = 42%) as we approached the mouth of the creek. This improvement may be a result of movement of mussels (as larvae attached to fish hosts) from the Scioto River.