Study On Safety Performance Of Highway Glass Fiber Reinforced Plastics Mortar Pipe Culvert Under Construction And Service

In recent years,the infrastructure construction of highway transportation has developed rapidly in China,the number of highway culverts is increasing,and the structure types of underground pipe culverts are constantly bringing forth new ideas.In view of the traditional reinforced concrete pipe culvert in the actual use of highway engineering have some quality problems,this paper creatively proposed with the FRPM pipe instead of the reinforced concrete pipe.As a new type of flexible composite pipe,FRPM pipe has excellent mechanical properties,and a sand layer structure is arranged in the middle to meet the strength and stiffness requirements of the buried pipe culvert.At present,the application research of FRPM pipe is mainly reflected in the field of water supply and drainage,chemical and petroleum,but there is few literature about the highway culvert.In view of this,the force and deformation characteristics of FRPM pipe were studied in depth through the material performance test,dynamic characteristics test and field test in this paper,which has the certain instruction significance to the FRPM pipe construction technology guide formulation and the highway popularization application.The research of this paper can be summarized as follows:(1)Analysis of manufacturing technology and process control of FRPM pipe.Based on the analysis of the quality control of three kinds of raw materials and the structure and characteristics of the wall,the manufacturing process and related quality control requirements of FRPM pipe were discussed,and the strength control of the mortar layer material was analyzed,which laid the foundation for the material performance test,the dynamic load test of the construction stage and the traffic operations field test.(2)Performance test of the FRPM pipe for experiment.The compression strength,elastic modulus,tensile strength,ring stiffness and residual ring stiffness under different fatigue loads of the FRPM pipe were obtained by compression performance test,tensile performance test,ring stiffness test and fatigue performance test which designed according to the relevant test standard.The results show that the performance parameters of FRPM pipe material can meet the strength requirements of highway culvert design,which provide the theoretical basis for the structure optimization design and the application of highway extension of FRPM pipe.(3)Study on dynamic characteristics of FRPM pipe culvert in construction stage.The construction technology of FRPM pipe culvert was systematically summarized and the dynamic load test scheme was designed.The fast Fourier transform method was used to obtain vibration velocity time course curve of the pipe top V and the tube side H and FFT spectral characteristic curve under the dynamic load.The natural frequency of pipe was calculated by ANSYS.The vibration frequency and maximum vibration velocity of FRPM pipes were compared and analyzed.(4)Field inspection and safety performance of FRPM pipe culvert under service condition.An overview of engineering application of FRPM pipe was introduced,and a field test of the safety condition of the operation of FRPM pipe under the condition of service was carried out.The strain and deformation characteristics of FRPM pipe and the deformation characteristics of the top deflection.And FRPM pipe material strength indicators were compared to get the result that buried FRPM pipe after a year of operation is in a good security situation,in order to achieve the FRPM pipe culvert highway application and promotion.