Bridge Design in Complex Environments of Xuzhou-Yanchcng HSR
Xuzhou-Yancheng HSR is a long railway line with complex geological and natural conditions,and the length of bridges accounts to a large proportion.For this railway,simply-supported girder bridge in high-intensity earthquake area was designed with hard resistance to earthquakes,for which innovative bearings were developed with optimized bearing layout and anti-beam-falling measures,and reference drawings of applicable pier were compiled.Seismic isolation design was adopted for continuous beam(arch)bridges.Seismic isolation bearings or the combination of seismic isolation bearings and dampers were selected according to site seismic parameters and bridge span.For bridges in deep soft soil areas,the distance from existing structures was controlled to not less than 150 m.More driven piles were used,and auxiliary construction methods such as pilot holes by screw drilling or high-pressure water jetting were adopted.The depth of pilot holes was less than 2/3 of the pile length,and the position where water jetting stops was not less than 3m from the pile bottom.For bridges in karst areas,the calculation boundary for pile foundation was identified according to the strength and thickness of upper and lower bedrocks of karst caves;for complex karst caves such as beaded karst caves,super-large pile group foundation was adopted to prevent pile foundation from entering karst caves and their affected areas.A 312 m continuous steel truss cable-stayed structure with double towers and double cable planes was adopted for the bridge crossing Xinyang Port,with a semi-floating system where the tower pier is consolidated while the tower and beam are separated,and a comprehensive vibration reduction design for stay cables;in order to improve the stability of the structure against typhoon during construction and in combination with the wind-resistant measures of structures,the side span support assembly and one-way cantilever assembly of main span was adopted.Considering parallel running of four railway lines at Huai'andong Railway Station and running of adjacent lines in the same direction,a non-standard simply-supported girder with a line spacing of 5.3 m was designed.A slight modification to conventional equipment was only required for precast beam erection equipment,which is convenient for construction.
NETL
NSTL
万方数据
