Open bottom fiber reinforced precast concrete arch unit

摘要

A one-piece open bottom fiber reinforced precast concrete arch unit is buried in compacted soil and has an arcuate top wall portion integrally connecting arcuate side wall portions. The fiber reinforced wall portions have a configuration which provides ductility and flexure strength for effectively utilizing the surrounding compacted soil to resist deflection of the unit in response to a load and to redistribute stresses in the unit. Each of the side wall portions of the unit has a reducing wall thickness towards its bottom and has a radius of curvature greater than the rise of the unit and at least twice the radius of curvature of the top wall portion. Bands of continuous fibers may be attached by adhesive resin to the outer surface of the arcuate side and top wall portions of the unit near opposite ends of the unit to increase the load carrying capacity of the unit.