Construction Control of Cable-Stayed Bridges Based on ANN and GA Hybrid Algorithm

斜拉桥施工控制英文论文

Construction Control of Cable-stayed Bridges Based on ANN and GA Hybrid

Algorithm

Zeying Yang1* , Haiming Yi1, Jianbo Qu2, Junjie Song3, Xuefu Li4

School of Civil and Hydraulic Engineering, Shandong University, Jinan, 250061, China; email: 2

Highway Bureau of Shandong Province. Jinan 250014, China 3

Highway Bureau of Weifang Municipality Weifang 261000, China 4

Highway Bureau of Weicheng urban area in Weifang Municipality, Weifang, 261021, China ABSTRACT

This paper presents a new method of using ANN (Artificial Neural Networks) to control cable-stayed bridges at deferent erection stages during construction: predicting height mark deviation of main beams of cable-stayed bridges during construction given influencing factors (temperature at the moment of measurement, depth of stretched cross-section of main beams, depth of discussed cross-section of main beams, distance between the stretched cross-sections of main beams and axle wire of pylons, and distance between the discussed cross-sections of main beams and axle wire of pylons). A hybrid algorithm (G-Prop) that combines a genetic algorithm (GA) and back-propagation (BP) is used to train ANN with a single hidden layer. The case study shows that ANN based on GA and BP is a powerful instrument for predicting height mark deviation of main beams of cable-stayed bridges during construction and for construction control of cable-stayed bridges. 1 INTRODUCTION

It is a fact that control of endogen force and deformation of cable-stayed

bridges at deferent erection stages during construction is very important for the cable-stayed bridges’ safety and durability. But how to control them into permitted ranges is still a big challenge for bridge engineers.

Because of self-anchored cable systems, the cantilever method has been

widely used for the main girder erection of cable-stayed bridges (Pao-Hsii Wang et al. 2004). The cantilever method is considered to be the natural and logical solution for constructing cable-stayed bridges of large span, where new girder segments are installed and then supported by new cable stays in each erection stage and the construction process keeps going stage-by-stage until the bridge is completed. Since no auxiliary supports are needed for constructing the bridge girder in the cantilever method, a lot of construction cost and time can be saved. There are two basic alternates to the cantilever method. One is named the single cantilever method and the other is the double cantilever method. In the former, the side span girders of the

1*

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