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Effect of Overturning Restraint on the Performance of Fully Sheathed and Perforated Timber Framed Shear WallsHeine, Christian Peter 22 January 1998 (has links)
This study investigates the monotonic and cyclic response of light-frame wood shear walls with and without openings. Effects of overturning restraint in the form of tie-down anchors and corner segments on light-frame shear walls with and without door and window openings were quantified. While the results are useful to refine a design methodology for shear walls containing openings, they also provide important knowledge that is needed to accurately quantify anchorage requirements for shear wall design, and assess remaining load and ductility capacity of wood frame buildings after earthquakes or hurricanes.
Sixteen full-scale wall specimens were tested using monotonic and sequential phased displacement (SPD) patterns. A total of five different wall configurations, five anchorage, and two loading conditions were used. All walls were eight feet (2.4m) high. Straight wall specimens were forty feet (12.2m) long, whereas corner walls measured twelve feet (3.7m) in length. The analysis includes data from a previous investigation in order to further expand the scope of this study. Results reveal that ultimate capacity and stiffness increase with increasing overturning restraint. A shift in failure mode was observed when overturning restraints were omitted. Accumulated damage experienced by the wall specimens tested cyclically was fairly uniform, regardless of the amount of overturning restraint or size of openings present. / Master of Science
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Loads on Tie-Down Systems for Floating Drilling Rigs during Hurricane ConditionsBae, Yoon Hyeok 16 January 2010 (has links)
Tie-down systems are used to fasten drilling rigs to the deck of offshore
structures during harsh environmental conditions such as hurricanes. During Hurricane
Ivan (2004) and Katrina (2005), a number of offshore structures were moved and several
tie-down systems were damaged. In the present study, the reaction force and connection
capacity of tie-down systems for a TLP and SPAR are investigated. The environmental
conditions are taken from the API Bulletin 2INT-MET which has been updated after
several major storms during 2004-2005. The hydrodynamic coefficients of the TLP and
SPAR are obtained using a 3D diffraction/radiation panel method. The motions of the
TLP and SPAR are then simulated in the time domain by using the hull-mooring-riser
coupled dynamic analysis tool CHARM3D. Based on the simulated motion and
acceleration time series, the inertial and gravity loads on derrick and skid base footing
are calculated. In addition to the inertial-gravity loads, wind forces exerted on the derrick
are also calculated. All the external forces and resultant hull motions are simulated for
100-year, 200-year and 1000-year storms to observe the derrick structural integrity with
increasing environmental intensity. Various environmental headings are also considered to find the maximum reaction forces. In the present method, the phase differences
between gravity-inertia forces and wind forces are taken into consideration to obtain
more realistic loads on derrick and skid base footings. This research shows that the
maximum and minimum load values are appreciably higher for the SPAR. In addition,
the direction of external forces is also important to determine maximum reaction forces
on footings. The capacities of the clamps in slip, bolt tension, and bolt shear can be also
analyzed using the resultant data to provide guidance on appropriate design values.
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Analysis of Anchors and Bracing Configurations for Personal Fall Arrest Systems in Residential ConstructionMorris, Justin Collins 20 June 2013 (has links)
Falls continue to be a major problem in the residential construction industry and account for a large number of injuries and fatalities each year (US Department of Labor, 2012). The effects of a fall are catastrophic to the workers and their families as well as the construction company and surrounding community. Prevention of these incidents has been the primary focus of organizations such as the Occupational Safety and Health Administration (OSHA). To reduce the number of falls on residential construction sites, OSHA has put forth several standards that require the use of fall protection. Although guidelines have been provided, there have been concerns and complaints regarding the standards as well as methods and materials that should be used.
The goal of this research was to measure the behavior of a five truss roof system with various anchor points and bracing configurations loaded by a horizontal force. A lab built roof system was used to test three different anchor types with three forms of temporary bracing. The materials and methodology used in this testing were based on common materials and practices currently used in the residential construction industry.
The results of this research show that anchors must engage multiple trusses to spread the applied load throughout the roof system. Several forms of temporary bracing such as lateral, diagonal, and sway bracing, are also required to strengthen the roof system allowing it to withstand an applied load. / Master of Science
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