Research On Key Technology Of The Integrated Deck Erection Gantry

In our country under the premise of economic and comprehensive national strength increasing,bridges and other infrastructure got greater development,highway bridge construction is gradually shifting from developed regions to backward mountainous area;The construction environment of highway bridge is worse,the structure is more complex,the construction is more difficult.Suspension bridge is a commonly used bridge to cross the mountain gorge.Due to the mountainous terrain limitation,poor transportation and construction conditions,it is more difficult to build the suspension bridge in the mountain area.At present,a variety of mountain suspension bridge stiffening girder erection equipment has been developed,such as deck erection gantry and cable crane;However,the deck erection gantry can only realize the vertical lifting or small Angle swing lifting of the stiffening girder of the suspension bridge,which cannot be transported horizontally.Although the cable crane can meet the transportation and erection requirements of the suspension bridge in the mountainous area,it needs a lot of auxiliary facilities,and the economic benefit of cable crane decreases rapidly with the span of the suspension bridge increases.In order to realize the mountain suspension bridge stiffening beam transportation and erection integration,reduce auxiliary facilities and increase economic benefits.This paper is based on the Dahe bridge in Guizhou province,and on the basis of the development of the common deck erection gantry to put forward the design scheme of the integrated deck erection gantry.Furthermore,the main structure of the scheme is designed and the key technologies are studied.This paper mainly includes the following aspects:(1)In the first place,the general situation of the Dahe bridge project was briefly introduced.The design requirements and operating conditions of the integrated deck erection gantry were analyzed in detail.In this paper,the main structure of the common deck erection gantry is compared and analyzed,and the design scheme of the crane is put forward.(2)The main girder and the walking mechanism of the integrated deck erection gantry were designed.ANSYS software is used to analyze and calculate the structure of integrating deck erection gantry in different working conditions.Let us know the main structure and the connection part stress characteristics and the most adverse working condition of the crane.(3)Preliminary design of the integrated deck erection gantry walking wheel and three ways to reduce the contact stress of the walking wheel and main cable are proposed,and Ansys software was used for analysis and verification.(4)Using the MATLAB software to simulate the wind field of the crane in the non-working state.At the same time,using the finite element program to analyze the wind time history.The analysis results of the analysis are compared with the results of static gust.(5)Modal analysis is carried out on the structure of the integrated crane,and the natural frequency and vibration modes of the crane structure are obtained.Transient dynamic analysis is carried out on the structure of the crane,and the dynamic performance of the structure in the process of girder lifting and girder walking are studied.