Analysis Of Mechanical Behavior Of Prefabricated Cantilever Subgrade Structure In Mountain Area

The construction of mountain highway plays an important role in promoting regional economic development and improving social benefits.With the construction of more and more mountain highway projects,some problems encountered are also raised more and more.In the changeable environment of mountainous terrain,traditional highway roadbed design schemes mostly need large quantities of excavation and filling,which makes the stability of roadbed not as easy to be guaranteed as in plain areas,and the assembled cantilever roadbed scheme proposed by some scholars can solve these problems to a certain extent.The design concept of assembled cantilever subgrade is to use cantilever structure to reduce the amount of earthwork and rock work,and to use prefabricated parts to assemble on site to save time and cost,and to ensure the quality of components through standard prefabricated parts,and prefabricated cantilever beams have adjustable base to adjust the beam-column connection position,so that prefabricated parts have better compatibility.However,the actual research results of this structure are few,so it is necessary to do further research on its mechanical performance.In this paper,the four-span cantilevered subgrade structure under mountainous conditions is taken as the research object.Through numerical simulation of the actual constraints and loads of the cantilevered subgrade,the mechanical behavior analysis of the cantilevered subgrade structure is carried out.By analyzing the stress and displacement of each component,the state of the cantilevered beams and columns is compared,and the structure under load is found to be different.Based on the displacement distribution law of components,the overall stability of slope is calculated by strength reduction method,and the safety factor of stability is obtained,and corresponding measures are put forward for weak parts.In view of the topographic fluctuation that mountainous areas may face,the relationship between the stability of rock,soil and cantilever subgrade and cantilever length is summarized by modifying the scheme of imposing cantilever subgrade and analyzing the change of structural mechanical behavior with different cantilever length as variables.By combining the cantilever beams with different cantilever lengths into a cantilever structure to form a composite structure,the mechanical behavior of different types of composite cantilever structures under the same working conditions is further compared.The results show that the cantilever subgrade with different cantilever beam lengths can make the stress of each beam-column member more uniform and reasonable to a certain extent.By setting different incident angles and different arrangement positions,the influence of different anchor arrangement modes on the overall stability of cantilever structure is analyzed,especially on the intermediate column and the intermediate cantilever beam.The results show that the anchor arrangement can obviously control the overall displacement of the roadbed,and the structural stability is insensitive to the incident angle of the anchor.The arrangement of bolts.A single cantilever structure,including the finite element model of anchor-bolt assembly joints,is established.The working performance of assembly joints of assembly structure is analyzed from the stress distribution of beams and columns.The setting of assembly joints of anchor-bolt is further discussed by changing the detail structure of joints.