강재 맨홀뚜껑의 보강구조 해석

Abstract

Manhole cover, which is usually made of grey cast iron and consists of frame and cover, should haveenough strength to support the heavy traffic load. The manhole cover made of cast iron has heavy weightto handle manually and is vulnerable to impact force with its brittle characteristics. Moreover, its productionprocess of casting has been regulated in terms of environmental pollution. In this study, steel manholecover is proposed to substitute the cast cover with a series of structural analyses to confirm its strength tosupport the test load for manhole cover. The cover of the proposed steel manhole cover is made of thincircular pate and stiffeners below the plate. Rectangular columns and hollow circular plate were selectedfor the shape of the stiffener. In order to give enough strength for the cover to behave within elastic rangein the loading, strengthening structures of the cover were varied with increasing the number and the sizeof the stiffeners. The results of the analyses revealed that when both the hollow circular stiffener andcross stiffeners were additionally applied at the same time to the steel cover with longitudinal stiffeners,the maximum stress level in the cover could be reduced to that level presented in the cast cover.