Experimental Study on Corrugated Steel Box Culvert Stress Characteristics During Backfill
Compared with the circular,arched and pipe-arch structures,the corrugated steel box culvert has higher section utilization rate and smaller minimum thickness of backfill soil.Therefore,it is more suitable for urban underground passages,bridge and culvert in plain areas and acrossing lines with limited subgrade elevation.However,there is currently a lack of experimental study on corrugated steel box culvert for China's clearance requirements.The applicability of internal force calculation formulas needs to be studied.The full-scale model test was conducted on a corrugated steel box culvert with 6.6 m span and 3.7 m rise.The displacement,internal force and earth pressure during backfill were tested and analyzed.The structure bending moment under dead load was compared with Duncan's calculation formula.The result indicates that the structure side continues deforming inward before backfill to haunch,and the top surface continues deforming upward.The deformation begins to reversely change after backfill to haunch.The final downward deflection of vault is 0.84%of the rise.The backfill to haunch and the end of backfill are the key construction stages.At both stages,the stresses on crown outside are the largest,which are 36 MPa(tensile)and ― 100 MPa(compression)respectively.The proportion of stresses,generated by the measuring points bending moment at vault and haunch,is 76%-100%of the total stresses after backfill.The earth pressure on structure top surface after backfill is greater than that calculated by using the soil column method.The earth pressure on side is less than the static earth pressure.The formula proposed by Duncan can effectively predict the bending moment under dead load with the propsed full-scale model with the error less than 11%.The study result can provide the reference for the subsequent specification development and structural design for corrugated steel box culvert.
bridge engineeringstress characteristicsmodel testcorrugated steel box culvertbackfill process
NETL
NSTL
万方数据
