Stridor is a sign of upper airway obstruction. In children, laryngomalacia is the most common cause of chronic stridor, while croup is the most common cause of acute stridor.Generally, an inspiratory stridor suggests airway obstruction above the glottis while an expiratory stridor is indicative of obstruction in the lower trachea. laryngeal web, cyst or laryngocele may present with stridor, usually at birth or soon after. Laryngotracheobronchitis (Viral Croup) . The most common cause of acute stridor in childhood is laryngotracheobronchitis, or viral croup.
The load in the floor beam is then transferred to the main load carrying system, such as a longitudinal plate girder. Per Article 9.8.3.1 of the AASHTO LRFD (5 th Edition, 2010), the deck plate is to act as a common flange of the ribs, the floor beams, and the main longitudinal components of the bridge.
This equals the area of the deck that's supported by the post multiplied by the combined design live and dead load (40 psf and 10 psf, in most cases). The area supported by the post is found by dividing in half the joist and beam spans on all sides of the post (Figure 1).