Research On Structural Stress Analysis And Construction Monitoring Of Special-shaped Pylon Cable-stayed Bridge

Cable-stayed bridges have become an important part of long-span bridges due to their unique shapes and large spanning capabilities.and are a complex structural system with high-order hyperstatics.Among them,the special-shaped pylon cable-stayed bridge breaks through the traditional cable-stayed bridge structure.The pylons are more diversified and their spatial forces are more complicated.Therefore,it is necessary to study the stress analysis and construction monitoring of the special-shaped pylon structure.The main contents are as follows.First,study the principles of determining reasonable bridge status and reasonable construction status and the method of cable force calculation.Through actual engineering examples,the bridge cable force is calculated by the zero displacement method and the minimum bending energy method,and the reasonable bridge cable force is compared.The scope of application and advantages and disadvantages of various methods.Reasonable construction state mainly introduces the principle of the unstressed state method,the method of solving the unstressed length in the two cases of considering the sag and the sag effect,and the two principles of the unstressed state method.Secondly,taking the Taizicheng cable-stayed bridge as an example,using the finite element to simulate the extraction of the unstressed cable length in a reasonable bridge state,and the accurate calculation of the unstressed cable length in the actual construction,the unstressed state method simulates the detailed process of the staged construction,Compared the effects of one-time bridge completion and phased construction on the internal force and line shape of the reasonable bridge state.After comparing the differences and connections between the two,the conclusions drawn can provide references for the construction and design of this type of bridge.Then the construction monitoring plan of the cable-stayed bridge is analyzed and researched,and the cutting length,hanging,tensioning sequence and the principle of frequency method test of the stayed cable are introduced in detail.The conclusions drawn can provide references for this type of bridge construction monitoring.Finally,the sensitive parameters of the cable-stayed bridge construction process are analyzed,and the changes of five sensitive parameters such as main girder stiffness,main girder bulk density,cable manufacturing error,cable initial tension,and temperature are selected.The influence of cable force,main girder alignment,main tower top displacement along the bridge direction,steel box girder,steel tower,and cable stress changes.Temperature,initial tension,and main girder bulk density are determined as the main sensitive parameters.The construction error analysis and decision-making provide a basis,and the conclusions drawn can provide references for this type of bridge design.