Control Method Of Cable Length Errors In Tension Structures Considering Structural Performance

Cable tension structures have found their wide application in all buildings.In the design and construction of tension structures,cables with un-adjustable cable length(CUACL)are often adopted to reduce costs,labors and time.This thesis mainly studied the influences of construction errors in tension structures when using UACLD,and proposed some proper control methods.The caveat of using CUACL is that the cable force distribution after pre-tensioning is entirely dependent on the initial cable lengths that are measured in their zero stress state.At first,some fundamental premises in analyses of initial cable length errors are proved using equilibrium matrix.The indicator of the sensitivity of initial cable length errors was proposed,and it is proved that the influences of different initial cable length errors could be linearly superposed.Moreover,it is proved that the influences of initial cable length errors were not related to the magnitude of the pre-stress in self-stress state.Then,the sensitivity of the initial cable length errors was analyzed based on two actual cable domes.Based all above,a method to calculate the control criteria of initial cable length errors was proposed by introducing the reliability theory and non-linear programming method.This method was widely suitable for tension structures.Upon these,three parameters which primarily influence the manufactural criteria of initial cable length errors were discussed: the allowable deviation of cable force,the allowable failure probability and the corresponding reliability index,and the qualified rate of the cable length in the cable manufacturing.In practice,these three parameters could be chosen by designers,based on whole structural characters and construction requirements of cable structure.The influences of all temperature changes in the life cycle of tension structures when using CUACL were analyzed,and were classified into two different categories.Based on this classification,the relationship between the influences of temperature changes and the boundary conditions were analyzed.Furthermore,a method to analyze the control criteria of different temperature changes was proposed by using an example of an actual cable dome.The pre-set deformation value of the cable net used in glass curtain wall was obtained.Different construction sequences in the installation of glasses were comparedand the best sequence was suggested.In addition,two different length errors in construction of cable net used in glass curtain wall when using CUACL were researched,i.e.initial cable length errors and errors occurred in connecting cable joints.A method to obtain the control criteria of these two construction errors simultaneously was proposed.A squre cable dome was designed to conduct the experiment study.Different load cases were applied on the cable dome to survey its structural performance.Upon this,the sensitivity of different cables was tested,and the influences of initial cable length errors on the structural behavior in load states were also experimented.Some conclusions obtained above were proved in the experiment.