Numerical Analysis And Experimental Study On Impact Resistance Of A New Type Of Assembled Pile Forest Structure

As a kind of natural disaster which is frequent in valley and gully,debris flow occurs by accident and carries a huge energy.Once it happens,it often does a disastrous damage to the surrounding buildings and people.Among them,the impact of rocks is one of the important factors causing damage.With the development of society,the reasonable and effective management of debris flow become a n issue that cannot be ignored.Based on the impact of national science and technology supporting plan—debris flow's new spatial grid protection structure theory and experiment research as the research background,does some improvement of existing pile—forest structure,and bring in a new type of prefabricated pile forest structure.In this paper,the basic components and units are analyzed and studied.The details are as follows:(1)Using the finite element software ANSYS/LS-DYNA,the multi-parameters(diameter of steel tube,wall thickness,mass and velocity of alluvium)of steel tube cantilever column are simulated and analyzed.The dynamic response characteristic curve of single cantilever column is obtained under different impulse response.At the same time,the destruction mechanism of the steel tube cantilever column is analyzed,and the destruction state of the components under the different impact energy is obtained.(2)Through experiments,the dynamic response of steel t ube cantilever column under the different impact energy and different impact height are studied and analyzed.The test result is verified by c omparing the displacement,acceleration and strain time curve with the simulation.At the same time,the experiment and simulation results are calculated and compared,and the increasing and decreasing trend of the characteristic values of concrete column impact and displacement are obtained.(3)Finite element software is used to analyze the parameters of different impact height and the impact quality of different types of assembled steel pipe units,and the variation rule is obtained.At the same time,ac cording to the final form of steel tube damage,finds the most unfavorable location of the unit.(4)According to the data acquisition system,the loading point and key point of prefabricated hollow steel tube and concrete filled steel tube which include displacement,acceleration,strain time history curve in the test are extracted and are compared with simulated data,which verifies the practical of prefabricated steel pipe unit.(5)According to the research results of steel cantilever components and prefabricated steel pipe unit,the new type of prefabricated pile forest structure is proposed,and its dynamic characteristic curve under the differe nt shock response are analyzed.And,a comparative analysis of the energy loss of the conventional pile—forest structure shows that the energy loss is within the acceptable range and can be put into use.