Study On Mechanical Property And Design Method Of High-backfill And Long-span Corrugated Steel Pipes

Nowadays most culverts are reinforced concrete structures, because reinforcedconcrete structures have the characteristics of fussy and long construction process,easily cracking and foundation settlement in use, especially in the condition of highbackfill in the roadbed, the normal use of the structure and transportation safety isaffected seriously. Looking for a kind of tructure with brief construction process,powerful bearing capacity and good economic performance becomes an importanttask for the technical personnel.Steel corrugated pipe structures overcome the shortcomings and insufficiency ofreinforced concrete structures effectively, and they have the following advantages:(1)High bearing capacity, strong resistance to deformation and foundation settlement.(2)shortening the time of the construction process.(3) Less cost, especially when thediameter of culvert is larger.In this paper, the main research contents and results are as follows:(1) With using ANSYS finite element method for the numerical calculation ofsteel corrugated pipe culvert, the structure mechanical characteristics, deformationregularity, effect of live load and changes of the backfill pressure about differentconstruction conditions and different parameters are analysed. The results show that,the sizes of the corrugated pipe culverts have a certain extent influence on theirperformance, the plank thickness affects the stress distribution of the structure and thefillback modulus plays an important role in structure force and deformation, however,when the fillback reaches14m, the force and deformation wouldn’t change any more.Live loading can be neglected when the fillback on the top tube reaches about9m. Inthe initial stages of fillback, unsymmetrical backfill has great influence on the steelcorrugated pipe culverts, but foundation settlement doesn’t have obvious effects on it.(2) Field experiment was carried out on the steel corrugated pipe culvert withhigh filled earth about researching mechanical properties, including the stress anddeformation of steel corrugated pipe culvert in the construction phase. The testoutcome shows: with increasing the height of fillback, soil-arch effect between thestructure and soil will be formed gradually around the steel corrugated pipe culverts,which relieves the structure stress and deformation effectively, also improves thestress state of structure. (3) Compparing the finite element calculation results with the test data, theresults indicate that the errors are within the prescribed scope. Based on the summaryanalysis, some reasonable design methods and construction suggestions are putforward, such as the choice of the waveform for corrugated pipe culvert, the design ofthe seam about ring to assemble position etc.(4) Combined with the actual situation of the project, the existing formula ofsteel corrugated pipe design methods are amended and optimized by comparing allkinds of steel corrugated pipe culvert codes. It can provide a certain value referencefor domestic researching on design of the steel corrugated pipe culverts.