Vertical Gradient Temperature Difference of the Main Arch with Single Pipe Section in Tibet Based on Statistical Analysis

Tuo Shi,Haoxu Li,Nianchun Deng,Zheng Chen

doi:10.1155/2020/9767621

Abstract

A 75 m long experimental arch with a 1.6 m diameter was constructed in Tibet for a one-year test to determine the most unfavourable vertical temperature difference for a single pipe in the main arch of a concrete-filled steel tube arch bridge. Actual temperature observation data were used to analyse the vertical temperature difference in the single circular pipe arch rib using statistical methods. The standard value for the vertical temperature difference in the single pipe under a return period of 50 years was calculated. The results showed that the influence range of the vertical gradient temperature was 25 cm. The vertical temperature difference followed a lognormal distribution, and the standard values of the positive temperature difference at the upper and lower ends of the single pipe were 16 and 10°C, respectively; the standard values of the negative temperature difference at the upper and lower ends of the single pipe were both -8°C under a return period of 50 years. These results are considerably different from the values specified in the current Chinese code. These could serve as references for calculations involving arch bridges in Tibet with single circular pipes in the main arches.

Highlights

Advancements in the construction technology of concretefilled steel tube (CFST) arch bridges support their economic advantages over a certain period [1,2,3]
A previous study [18] reported that the influence range of the gradient temperature difference in a single pipe was 25 cm (d 25 cm)
Large volumes of test data were statistically analysed to verify the influence range of the gradient temperature difference in a single circular pipe. e probability distribution function form of the gradient temperature difference was obtained in addition to the standard values of the temperature differences corresponding to a 50-year return period. e findings of this study can serve as references for determining the temperature load parameter values using the Chinese bridge design codes. e following conclusions can be drawn from the study: (1) e maximum influence range of the gradient temperature difference in a single pipe was 0.25 m

Summary

Introduction

Advancements in the construction technology of concretefilled steel tube (CFST) arch bridges support their economic advantages over a certain period [1,2,3]. Owing to these economic advantages, there is a demand for building a CFST arch bridge on the Sichuan–Tibet line. Some scholars have studied the gradient temperature difference in steel box girders. Wang et al [8] studied a curved steel box girder bridge in Hangzhou, obtained the nonlinear temperature field under sunshine, and analysed the overturning stability of the bridge

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