Study On Key Technologies Of System Transformation Of Self-anchored Suspension Bridge Cable-stayed Method

Self-anchored suspension bridge is beautiful in appearance,novel structure,landscape and modeling advantages make this bridge type has a certain competitiveness.At present,the construction of self anchored suspension bridge has the construction method of support and non-support,and the development trend of the construction technology of the self anchored suspension bridge is non-support.However,the commonly used non-support construction technology system conversion is more complex,for the temporary anchor or anchor pier set up a higher demand,and temporary anchorage construction occupied space.Therefore,it is necessary to seek a way to facilitate the realization of the system conversion,and does not take up space,and is non-support construction technology.The construction method of cable-stayed is the construction method sought.In the thesis,the basic criterion of the system conversion of cable-stayed method is proposed,and the key technical contents of the system conversion are extracted.In order to study the tension process of the slings from the aspects of the effectiveness of the work,the energy relation of the sling process is deduced based on the energy principle,and an accurate algorithm for the work of the sling is proposed.And then combined with the actual sling tension process:the characteristics of structural deformation and the force,the actual work of the jack,then the approximate formula and the expression of the total work are deduced.And put forward the concept of work efficiency ? of tensioning equipment.Which provides a theoretical basis for the study of the conversion of the system.In the thesis,combined with the characteristics of the engineering background,through the analysis of key technologies,three typical system conversion schemes are proposed,and the bridge nonlinear system BNLAS is used to study the system conversion scheme.In the thesis,the following contents of the typical system conversion scheme are studied:the control of the state of the cable-stayed bridge,the thrust mechanism of the saddle and the characteristics of the bridge tower,the tensioning scheme of the sling,the removal of the cable and the deformation and force of the whole process.The characteristics and related laws of the cable-stayed method are analyzed comprehensively,and the feasibility of the cable-stayed method is proved.The typical scheme is evaluated synthetically,and a comprehensive and better construction scheme is put forward.Parameter identification and correction of self-anchored suspension bridge occupy an important position in construction control.In the thesis,the method of parameter sensitivity analysis in stages is put forward.The sensitivity of the parameters is analyzed by BNLAS,and the main design parameters of each stage are obtained.Finally,the method of parameter identification in stages is proposed in the thesis.The BP neural network algorithm is used to construct the neural network of bridge model correction by using the neural network toolbox in MATLAB.The uniformity of the design method is used to design the sample group.The internal forces and displacements of the previous construction stages are trained as the sample input values.Then,the training network is used to identify the parameters of the bridge and to modify the finite element model in stages,and the minimum number of construction stages to meet the parameter identification requirements is determined,which ensures the construction precision in time.