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Research On Bearing Capacity And Deformation Mechanism Of Inclined Pile Group Under Complex Loads

Posted on:2023-04-28Degree:MasterType:Thesis
Country:ChinaCandidate:B J ZhangFull Text:PDF
GTID:2532307154470724Subject:Civil engineering
Abstract/Summary:PDF Full Text Request
In some complex engineering structure foundations,inclined piles can be set to resist the horizontal load of the structure,but the understanding of the load mechanism of inclined pile groups under complex load conditions is still very limited.In this paper,an indoor model test is firstly designed to study the deformation and stress characteristics of inclined pile groups under horizontal loads.Based on the test results,the finite element software ABAQUS is used for modeling and verification,and the inclination of different pile arrangements is further analyzed.The stress and deformation characteristics and action mechanism of pile groups under different working conditions.The main work contents and research conclusions are as follows:According to the horizontal loading model test and finite element simulation of the inclined pile group,it is found that under the same working conditions,setting a certain angle of inclined piles in the pile group can improve the horizontal bearing capacity.The change trend of the horizontal bearing capacity of the same-direction inclined pile group is similar to that of the inclined single pile,and the change rule of the horizontal bearing capacity is positive inclined pile>straight pile>negative inclined pile.In the symmetrical inclined pile group,with the increase of the inclination angle of the pile body,the bending moment of the pile body gradually decreases,and the frictional resistance of the pile side gradually increases,which can effectively reduce the horizontal displacement of the pile top and the vertical displacement of the pile bottom,and weaken the uplift of the soil around the pile.phenomenon,and the larger the inclination angle of the pile body in the inclined pile group,the smaller the horizontal displacement.The symmetrical combination of inclined pile groups is better than the same-direction combination.The key to improving the horizontal bearing capacity of the inclined pile group lies in the spatial rigid frame effect of the pile group and the exertion of the horizontal component of the lateral friction resistance of the inclined pile.Due to the strong cohesion of the clay itself,compared with the sandy soil conditions,the settlement phenomenon of the soil around the piles of the positively inclined piles and the uplift phenomenon of the soils around the piles of the negatively inclined piles are more obvious.Compared with the clay conditions,it is beneficial to exert the lateral friction resistance of the pile.For inclined pile groups with different pile layout methods,the horizontal displacement of the pile top in the hinged method is increased by 35%-50%compared with the rigid connection method.The symmetrical combination of piles is conducive to the exertion of the spatial rigid frame effect of the pile group.The inclined pile group in the form of symmetrical combination can improve the vertical bearing capacity of the pile group to a certain extent,and the increase range is about 2%;while the inclined pile group in the same direction combination can reduce the vertical bearing capacity to a certain extent,and the reduction range is about 2%.within 5%.Applying a vertical load can reduce the horizontal displacement of the pile top to a certain extent.When the applied oblique load is consistent with the direction of the same-direction inclined pile group,the oblique bearing capacity of the samedirection inclined pile group is greatly improved compared with that of the straight group,which increases by about 20%.In this state,the structural bending moment distribution is the smallest and the resulting The horizontal displacement is also the smallest,which is beneficial to the structural stress.
Keywords/Search Tags:Inclined pile group, Finite element simulation, Model test, Stress mechanism, Bearing capacity characteristics
PDF Full Text Request
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