Force Characteristics Of Mountain Highway And Engineering Application Of Large Diameter Steel Bellows Culvert

Traditional culvert is usually made by stone,concrete or the combination of concrete and steel.During the construction,some problems such as insufficient capacity and durability of stone,concrete shrinkage and creep,corrosion of steel and the shortcomings and applicable conditions of different type of culvert,will lead to some unnecessary issues.Faced with these practical engineering problems,the need for a new form of culvert is urgent.The new form of culvert has the following features,such as short construction period,low cost,easy to maintenance and repair and adapt to complicated hydrogeological condition.To sum up,it is imminently to research the new corrugated culvert.From domestic and foreign research and application,combined with Chongqing 13 new corrugated steel culvert repair,using the large finite element software ANSYS to analyze the changes in the force and deformation characteristics under different factors,the main conclusions are as follows:(1)Based on the calculation method of action in four popular at home and abroad for detailed comparative analysis form,results in the design phase,construction phase use CHBDC law closer to the actual situation;in the proof stage,when the filling height of less than 2m,the use of AISI law;when the filling height greater than 2m using CHBDC method.When calculating live load calculation should choose their specifications,more practical.Projects put forward by the degree of compaction of the elastic modulus of graded gravel great influence on the degree of compaction of 96% of the elastic modulus is 85% of 1.66 times.(2)introduced this steel Q235 strengths and fatal flaws,and anti-corruption measures were discussed in the construction process using ductile ceramic membrane for a second anti-corrosion measures,the theoretical life of up to 100 years;the basic assumptions for the thin shell theory It analyzes the bellows culvert can use this theory conditions.Obtain numerical analysis method is suitable for the bellows culvert,while specifically addressed the effect of waveform parameters on the bellows force and deformation of the culvert.(3)This paper analyzes the fill height of the outer wall of the bellows peaks and valleys of force and deformation of the law,obtained at the time of filling height greater than 7m dominant position and draw the corresponding relationship.For seven feature position force and deformation has been analyzed,wave top maximum force,minimum force and right 90 degrees.For bellows culvert is equivalent force growth rate is greater than the peak position all the features of the trough,where the growth rate is the fastest wave top.Backfill thickness of the flexible material should be filling height of 0.25 to 0.4 times,and 0.4 times that best meet soil arching effect.(4)The main conclusions are applied to the design and construction,summed up dead and live load calculation methods applicable national conditions and load combinations.The degree of compaction of the backfill material and the key factors analyzed separately,the maximum particle backfill material should be controlled within 50 mm,layer thickness in the range of 150 mm ~ 250 mm.When the top of the backfill material bellows height is less than 50 cm,can not walk or use a roller 8t and associated load thereon;when the backfill material height greater than 50 cm,you can start small vibration compaction machine.