Research On The Application Of Large-scale Pneumatic Shield Gate System In Urban Rivers In Mountainous Areas

With the national attention to ecological environment protection and the rapid development of river governance and urban ecological water system engineering,it is conducive to the design and research of new landscape dam with novel design and unique shape of urban environmental ecology.The new pneumatic shield gate system has become an important research direction of urban landscape engineering.Taking four pneumatic shield gates in the comprehensive treatment project of hongyanqiao yejiazhuang reach of Nanming River in Guiyang as the object,this paper carries out the application research of pneumatic shield gate system with 60 m width and 8m height in urban rivers in mountainous areas.The main research contents of this paper are as follows:First,the advantages and disadvantages of water retaining structures commonly used in urban river landscape engineering at the present stage,such as rubber dam,hydraulic automatic flap dam(including hydraulic flap dam),bottom shaft rotating steel dam and pneumatic shield gate system,are compared and analyzed,and the boundary condition requirements of pneumatic shield gate system layout and its advantages in mountainous river cities and towns are summarized.Secondly,through the analysis,summary and derivation of mechanical model,the calculation methods and formulas of key parts such as air bag,anchor,hinge,fixture and suppression belt in pneumatic shield gate system are deduced;Through the analysis and calculation of finite element software ANSYS,the most unfavorable working condition of door structure design is found.Finally,through the establishment and operation of multi-level(4-level)pneumatic shield gate system,water regime measurement and reporting system and multi-level joint control system in Nanming River comprehensive treatment project,the operation and dispatching data from July 2013 to may 2020 are collected,and the joint flood control dispatching mode of multi-level pneumatic shield gate system and the scouring and silting capacity of the river channel by using the head in front of the dam are summarized to improve the flood discharge capacity of the river channel;The influence of the operation of the pneumatic shield gate system on the on the particle bed load of urban rivers in mountainous areas is also analyzed and studied,and the operation scheme under this condition is preliminarily put forward to meet the needs of long-term operation.The research conclusion of this paper has certain guidance and reference value for the design(layout),use and operation management of pneumatic shield gate system in urban rivers in mountainous areas.