Research On Construction Monitoring Technology Of Self-anchored Urban Landscape Suspension Bridge

Since the 21 st century,the transport infrastructure in China has developed with an unprecedented speed.There appear kinds of landscape bridges which are designed innovatively and full of unique style in urban areas.Most of the landscape bridges have a harmonious and coordinated beauty.As one of the main selection of urban landscape bridges,suspension bridge has a high aesthetic value with its light structure and beautiful shape.The urban landscape suspension bridge is quite different from the traditional suspension bridge.For landscape needs,its bridge tower is always higher than the traditional and the main cable slope is steeper,which brings great difficulties to the actual construction.Based on the particularity of urban landscape suspension bridge,this study aims at making the classification of the suspension bridge,describing its characteristics of the force system and summing up the structure selection of the city landscape bridge.Combined with the anchor suspension bridge project example,the construction of suspension bridge tower and tension adjustment process is monitored.During the entire monitoring process,MIDAS/Civil and ANSYS are employed a detailed simulation analysis of the main cable and pagoda.In this study,the strain,linear and elevation of tower and main beam are monitored.The system conversion and recruiting program are carried out.And with the analysis of the stress,cable force,line shape and temperature of bridge structure in the whole construction process,the study draws the following conclusions:(1)The inlet temperature of bulk concrete such as pagoda and anchorage is 26.3℃ and the maximum temperature during the coagulation hardening process is 70.1℃ with an increase of 43.8℃,which is less than the specification of 50℃ and meets the requirements.(2)During the tower construction stage,the sections of the tower are in full compression.With the pouring construction of the pagoda concrete section,the compressive stress of the tower test sections increases substantially linearly with error which is less than 0.5MPa compared with design values.During the process of system conversion,the maximum compressive stress is-7.4MPa and the maximum tensile stress is 1.862 MPa,which is in a good consistency with the theoretical calculation value and meet the construction specifications and design requirements.(3)In the process of sling tension,the actual measured tensile value is in good agreement with the calculated value.After the adjustment of first stage and the cable force of the completed bridge,the maximum deviation between sling force of the completed bridge and the designed value is 13.5%,which means that the internal force distribution of the full-bridge sling is quite uniform.(4)According to the monitor results of the steel box girder,the maximum tensile stress of the main beam is 29 MPa and the maximum compressive stress is 30 MPa.There is no abruption of the stress and the construction process is safe.(5)The construction monitoring and control practice of Chaohe bridge show that complex ground anchor suspension bridge can be constructed by the system conversion method of self-anchored suspension bridge.Beam and cable is constructed at the same time,which is saving duration.The successful experience of monitoring and control of bridge construction can provide reference for future bridge monitoring and control.