Study On Force And Deformation Characteristics Of Ditch-buried Corrugated Steel Pipe Culvert Of Highway

As a structure with good deformation and stress,steel corrugated pipe culvert has the advantages of convenient construction,fast construction speed,strong anti-corrosion ability and low construction cost.It can solve the problems of cracking of concrete slab and settlement of foundation caused by traditional reinforced concrete culvert.However,due to the existence of corrugated steel bellows,the distribution of stress and earth pressure on the top of the pipe is relatively complex,which needs further study.Taking a steel bellows culvert in Yan'an North Frontier Line as an example,based on field test,theoretical analysis and finite element simulation,the strain,the section deformation and surrounding earth pressure of the steel bellows culvert are systematically studied.The main results are as follows:(1)Through the field test,the mechanical behavior of the steel corrugated pipe culvert during the layered filling construction is analyzed.The variation of the strain at the peak,wave side and trough of the steel bellows pipe culvert with the layered filling construction is obtained.The variation law of horizontal and transverse deformation of corrugated pipe section with layered filling construction and the distribution law of soil pressure around steel corrugated pipe culvert are obtained.The results can provide important reference value for construction design of steel corrugated pipe culvert.(2)Based on the layered analysis method,the small principal stress arch formed by principal stress deflection of soil under groove friction is analyzed,the lateral earth pressure coefficient considering the effect of soil arch is obtained,and the calculation formula of vertical earth pressure on culvert top(rectangular groove,trapezoidal groove)is derived.The calculation results are in good agreement with the experimental data.The parameters such as groove width,internal friction angle and filling height are analyzed.The influence of the number on the vertical earth pressure at the top of the culvert is studied,and the law of the vertical earth pressure coefficient at the top of the culvert is obtained,which provides a reference for the calculation of the vertical earth pressure at the top of the steel corrugated culvert.(3)The finite element calculation model of steel corrugated culvert in trench-buried highway is established.The influence of the parameters such as the modulus of foundation soil,the height of overburden soil and the waveform of corrugated culvert on the cross-section deformation of corrugated culvert and the earth pressure on the top of the culvert is systematically analyzed.The influence of the elastic modulus of the soil,the height of the overburden,and the waveform of the bellows culvert(wavelength,wave height,wall thickness)is analyzed,and the variation law of vertical and horizontal deformation of the pipe culvert and the vertical earth pressure at the top of the pipe culvert is obtained.The numerical calculation is compared with the field measurement.The results of the finite element simulation are in good agreement with the field measurement.The established finite element model is used to investigate the influence of foundation soil properties,filling height and corrugation parameters on the stress deformation of steel corrugated culvert.