Study On Mechanical Performance Of Buried Metal Reinforced Polyethylene Spirally Corrugated Pipe Culverts

Metal reinforced polyethylene spirally corrugated pipe combine the advantages of high-density polyethylene and steel with good corrosion resistance and high load-bearing capacity.Scholars at home and abroad have carried out a series of theoretical and experimental studies on it,and it has been widely used in municipal drainage and petrochemical pipelines.However,the metal-reinforced polyethylene spirally corrugated pipe application in highway engineering is less,and the research is not deep enough.To enlarge the application of this kind of pipe culvert in highway water culverts and emergency rush projects,a metal reinforced polyethylene spirally corrugated pipe side by side bunching system and a fast construction method of sandbag stacking and backfilling are put forward.Through experiments and numerical simulations,the following researches are carried out: a)The mechanical behavior and influencing factors of single-channel and multi-channel side-by-side metal-reinforced polyethylene spiral corrugated pipe culverts during backfilling construction;b)Mechanical properties and influencing factors of the side-by-side binding system under backfill construction and simulated deep-buried conditions;c)Steel strips with different structural arrangements enhance the difference in bearing capacity of PE pipes and culverts.The main conclusions of this paper are as follows:(1)The steel strip reinforced PE pipe is equivalent to a flat straight pipe using the equivalent modulus approach.The back-fill compaction process was simulated using the additional load method.The obtained two-dimensional plane strain numerical simulation method can more accurately simulate the force change behavior of the steel strip reinforced PE pipe culvert during the construction back-fill process.The simulation method has the advantages of simple modeling and high computational efficiency;(2)With increasing trench width and compaction pressure,the peak deflection of the single-channel steel-belt reinforced PE pipe culvert increases.The effect of the friction angle of the backfill material on the deformation of the pipe is not significant.The deformation and internal force of the multi-channel side-by-side steel belt reinforced PE pipe and culvert during the backfill construction process are most sensitive to the elastic modulus of the backfill material between the pipes.The deformation characteristics of each pipe during the backfilling and compaction process of the side-by-side bundling system are similar to those of a single pipe.During the backfilling construction stage,a "negative soil arch" effect is formed above the top of the PE pipe reinforced with a single steel strip,and the soil arch rate ρ on the pipe is between 1.3 and 1.6.After the backfilling of the side-by-side bundling system is completed,the vertical earth pressure on the pipe is less than the pressure of the overlying soil column,and the top of the pipe shows the effect of a "positive soil arch";(3)During the loading process of the simulated cover soil load,the horizontal deformation of each tube in the side-by-side bundling system is about 50% of the vertical deformation.The impact of backfill construction quality on the bearing capacity of the side-by-side bundling system is very significant.When the vertical deformation rate of the middle pipe is 5%,the bearing capacity of the side-by-side bundling system under the standard construction conditions is increased by 86.25% compared with the rapid backfill construction conditions;(4)During the loading process of simulating the cover soil loading,the soil around the pipe of the side-by-side bundling system exhibits a positive soil arch effect.The bearing capacity of the side-by-side bundling system is positively correlated with the compaction of the soil around the pipe and the hoop stiffness of the pipe.Under the condition of the same hoop stiffness,the effect of pipe diameter on the bearing capacity of the side-by-side bundling system is not significant;(5)The development laws of the load-deformation curves of the steel strip reinforced PE pipes with different structural arrangements are different.Under the condition of the same deformation rate,the bearing capacity of the side-by-side bundling system is the highest,followed by multi-pipe side-by-side,and the PE pipe culvert reinforced by a single-channel steel belt is the lowest.When the vertical deformation rate is 5%,the bearing capacity of the side-by-side bundling system is 1.63 times that of the single pipe.