In extra-thick coal seams, mining operations can lead to large-scale disturbances, complex overburden structures, and frequent and strong strata behavior in the stope, which are serious threats to mine safety. This study analyzed the overburden structure and strata behavior and proposed the technique of confined blasting in water-filled deep holes as a measure to prevent strong rock pressure. I...

Many strucrural engineers are surprised to learn that the In~rnotional Building Code (IBC, 2009) requires the roof structure to be engineered for standing water weight in the vicinity of the drains and scuppers regardless of roof slope. In addition, some low-slope roofs also require special attenlion for water weight and stiffness for safety against ponding failures or protection against accele...

Sustainability addresses the need to reduce structure’s impact on environment but does not environment’s structure. To explore this relationship, study focuses quantifying of green roofs or vegetated seismic responses such as story displacements, interstory drifts, and floor level accelerations. Using an archetype three-story steel moment frame, nonlinear time history analyses are conducted in ...

The identification and representation of building roof topology are basic, but important, issues for 3D building model reconstruction from point clouds. Always, the roof topology is expressed by the roof topology graph (RTG), which stores the plane–plane adjacencies as graph edges. As the decision of the graph edges is often based on local statistics between adjacent planes, topology errors can...

Youth gangs are on the rise. Today they threaten virtually every major city, many small communities, and even rural areas. The Office of Juvenile Justice and Delinquency Prevention (OJJDP) is committed to helping communities overcome this problem, and an essential first step is understanding the factors that contribute to the growth of youth gangs and the relationship of gang membership to deli...

The designer of convertible vehicles needs to consider the acoustical properties, quality of the interior environment, fatigue life and the aesthetic integrity of the flexible roof. Each of these concerns is affected, to a greater or lesser extent, by the interaction of the flexible roof material and its supporting structure with the aerodynamic loading on the material. For many convertibles, t...

In an urban area, the roof is the only available surface that can be utilized for installing solar photovoltaics (PV), and the active surface area depends on the type of roof. Shadows on a solar panel can be caused by nearby tall buildings, construction materials such as water tanks, or the roof configuration itself. The azimuth angle of the sun varies, based on the season and the time of day. ...

The drainage of low-sloped roof systems involves multiple design professionals, and often each has a different opinion as to their design responsibility. Roofing issues have been identified as being a number one source of litigation, and rain-induced roof collapses continue to occur with alarming frequency. With the backdrop of several rain-induced roof collapses, this paper illustrates the com...

An experimental study was conducted to quantify the characteristics of a tornado-like vortex and to reveal the dynamics of the flow-structure interactions between a low-rise, gable-roof building model and swirling, turbulent tornado-like winds. The experimental work was conducted by using a large-scale tornado simulator located in the Aerospace Engineering Department of Iowa State University. I...