Study On Pivotal Construction Technique Of Spatial Cables Self-anchored Suspension Bridge With Single Tower

Spatial cable plane self-anchored suspension bridge is a novel bridge type,comparing with the traditional parallel cable plane self-anchored suspension bridge,its modelling is more beautiful and more stereoscopic,but also the aspect of structure stressing is improved.Comparing with earth-anchored suspension bridge,spatial cable plane self-anchored suspension bridge starts later,and its theory is not mature enough..This paper chooses the south branch of Songyuan Tianhe Bridge(spatial cable plane self-anchored suspension bridge with single tower with span100 m + 100 m)as the research background to research the pivotal construction technique of spatial cable plane self-anchored suspension bridge with single tower.In this paper,use theory of finite element to analyse and use finite element software MIDAS Civil2012 to build model and analyse,focus on calculation of cable curve and comparison and selection of suspender tension scheme of spatial cable plane self-anchored suspension bridge.The main research contents and results are as follows:1.This paper studies cable curve of spatial cable plane self-anchored suspension bridge.Use the finite element software MIDAS Cvil2012 to analyse and get the model of completion condition,cable curve under completion state is achieved,but also the unmodified cables and suspenders unstressed length.Correck the unmodified cables unstressed length on main cable saddle,finally get an accurate cables unstressed length,this is fabrication length of the main cable.Correck the unmodified suspenders unstressed length on the clamp and get an accurate suspenders unstressed length,this is the fabrication length of suspender.Use backward analysis to get empty-cable condition of this bridge and obtained cable curve of empty-cable condition.Contrast the cable curve of completion condition and empty-cable condition and obtained the offsets of main cable saddle.Actual construction and measure must be considered,according to sizes and positions of the clamps,we must confirm coordinate of every clamp.2.The analysis methods of the suspender tension have backward analysis method?forward analysis method and stress-free status method.This paper uses forward analysis method and draws up four tension plans of the hanger,then compares and analysises the four tension plans of the hanger detailedly.In the analysis of construction stage,numerical value of stress at the bottom of the main tower?errors of the line shape of the girder and design line shape?internal forces at each construction stage of the girder?errors of the line shape of the main cable and design line shape?the maximum internal forces at each construction stage of the main cable?internal forces of every suspender at different construction stages and analysis of the state of the release of the main girder are compared detailedly;Then the influences of construction factors are considered,the numbers of jacks on the four tension plans of the hanger?the numbers of tension and the numbers of the assistant hangers at construction process are analysised.With construction stages and consttuction factors are analysised,the optimum tension plan of the hanger is obtained finally.