สัดส่วนผลตอบสนองของคานสะพานช่วงเดี่ยวธรรมดาเนื่องจากรถบรรทุกไทยและน้ำหนักบรรทุกจร HL-93

Abstract

Abstract

Bridge designpractices in Thailand havecommonly referred to the design specifications specified bythe American Association of State Highway and Transportation Officials (AASHTO). The design provisions of the current specifications employ the Load and Resistance Factor Design (LRFD) methodology. Furthermore, vehicular live loadings designated as HL-93 was developed in the specifications for the design purposes. However, Thai truck weights are different from those highway live loadings. This article has studied the maximum responses of simple beam bridges with the length ranging from 5-60 meters due to Thai trucks and HL-93 loadings. This study aims to compare the maximum shear and bending moment of the simple beam bridges. The proper ratios of the shear, also bending moment, between Thai trucks and HL-93 are proposed. The results show that, in each span, the maximum shear and bending moment are induced by different types of trucks. Additionally, the heaviest trucks produce the maximum responses for some analysis cases. For various bridge span length, the shear ratios and the moment ratios are varied from0.89 to 1.34 and 0.90 to 1.25, respectively. For bridge design practice in Thailand, these ratios could be applied as multiplier to HL-93, therefore, the maximum responses of simple beam bridge caused by the proportioned of HL-93 and Thai trucks are conformable.