Study On Vertical Bearing Mechanism Of Single Pile With Full-rammed Long Concrete

The full-rammed long concrete concrete piles have the effect of increasing the working area of the pile and pile around the soil.It has improved the traditional foundation treatment in all kinds of construction projects.It has the advantages of high bearing capacity and strong stability,which can improve the uneven settlement and have good performance.However,there are still some problems in the process of engineering application,such as bearing mechanism,bearing capacity calculation method,ramming and tightening effect,etc.In this paper,we will study the vertical bearing mechanism of single pile.Firstly,through the indoor model test,the load settlement curve,the crowded influence range of the soil around the pile and the distance between the different heads are studied.The results show that the homogeneous sandy soil compared with the rammed pile and ordinary straight pile,according to the earth pressure gauge test results show that the soil pressure in the pile below the head is the largest load below,followed by the position is obliquely below,and finally is to expand the longitudinal direction of the head,the distance between the enlarged heads should be greater than 2 times the diameter of the expansion head is appropriate,in the load stage,the load sedimentation curve changes relatively flat early,continue to load the load sedimentation curve showed a "double peak",showing the pile expansion head and the pile head to expand the head of the scattered load,increasing the vertical bearing capacity of single pile.Secondly,this paper uses the finite difference analysis software to analyze the influence of the distance between the head of the fully rammed long concrete concrete expansion pile on the load transfer,the stress and strain of the soil around the pile and the change of the axial force of the pile.The results show that the bearing capacity of the single pile is about 1.5~2.5 times that of the ordinary straight pile and 1~1.5 times of the rammed pile.The soil around the head is enlarged in the sand.The stress of the soil is relatively obvious,and the stress of the soil changes greatly in the position of the head and up and down,and the load of the soil under the head is enlarged.In the process of loading the pile top,and the failure mode of the pile type is piercing and destroying.Thirdly,the field test data are compared with the theoretical and model tests.The data is consistent with the results of the theoretical calculation and analysis,revealing the transmission characteristics of the load,and further confirming the rationality of the calculation method of the bearing capacity.Finally,this paper analyzes the law of load transfer of fully-rammed long concrete reinforced concrete piles,which mainly analyzes the influence of the vertical pressure bearing mechanism,the failure mode and the head resistance of the pile and the analysis of the influence of the head end of the pile,the relevant factors and characteristics of the vertical bearing of the single pile are obtained and the bearing transfer mechanism is combined with the engineering practice.Considering the multiple factors,the relative fit calculation formula of vertical bearing capacity of single pile of concrete.