新旧规范下混合配束混凝土箱梁承载力研究

Research on Bearing Capacity of Mixed Bundle Concrete Box Girders under Old and New Codes

摘要:

对某体外体内混合配束三跨连续箱梁进行了结构检测，得到结构承载能力检算系数，然后进行了新旧规范下承载能力的计算对比。因新旧规范在荷载组合、预应力次效应是否计入承载能力荷载效应规定不同，故结构特征点位的弯矩组合值差别较大。对结构在新旧规范下的承载能力进行检算。由计算结果可知，在考虑断束的工况下，按旧规范验算，结构抗弯、抗剪承载能力能满足原汽—20的荷载要求。在考虑断束的工况下，按新规范验算，抗弯承载力验算不能满足公路—Ⅱ级要求，抗剪承载力满足公路—Ⅱ级要求。

Abstract:

Structural inspection is carried out on a three-span continuous box girder with a mixture of external and internal bundles, and the calculation coefficient of structural bearing capacity is obtained. Then, the calculation and comparison of the bearing capacity under the old and new standards are conducted. Due to differences between the old and new codes in load combinations and whether the secondary effects of prestressing are included in the bearing capacity load effects, the combined moment values at characteristic points of the structure vary significantly. The bearing capacity of the structure under the old and new codes are calculated. The calculation results indicate that under the condition of considering the broken bundle, according to the verification of the old code, the bending and shear bearing capacity of the structure can meet the load requirements of the original Truck-20. Under the condition of considering the broken bundle, according to the verification of the new code, the bending bearing capacity verification cannot meet the requirements of Highway-Grade II, while the shear bearing capacity meets the requirements of Highway-Grade II.