Study About The Work Properties Of Nodular Pile Under Vertical Loads

Nodular pile is a new kind of prestressed pipe pile, its single pile bearing force increases with the pile- soil contact area by adding the annular convex ribs and longitudinal convex ribs in the pile lateral, and it is piled in soil by static pressure, so it has the characteristics of energy saving, material saving, green environmental protection, economic benefits and so on.At present, Nodular pile has application in part engineering; its well mechanical property and economic benefit have been embodied, but its stress mechanism is complex and its design and construction is still in initial stage, there is a lack of theory.research.Based on great amount of domestic and broad references, this dissertation presents the further study of the load transfer character, settling character and damage characteristics of nodular pile, by indoor experiment, field test and finite element analysis. The specific work is as follows:(1) By comparing 4 groups indoor contrast test, we research the bearing behavior of constant section pipe pile and 3 kinds of nodular piles whose bamboo spacing are 5cm, 7.5cm, 10 cm under the vertical load. According to analyze and contrast their pile-top displacement, radial soil pressure around pile and pile strain, we reach the compression strength of nodular piles is larger than constant section pipe piles, and ultimate bearing capacity of nodular pile whose bamboo space is 5cm is largest, the settlement is smallest.(2) By comparing 1 groups indoor contrast test,we research the bearing behavior between the different bamboo decoration.The result will be the bamboo layout department is more conducive to the spread of the load, good for control the subsidence.(3) In an engineering construction, we choose the constant section pipe pile and nodular pile whose diameter is equal to test. The test result shows that the design bearing capacity of nodular piles is larger than constant section pipe piles.(4) According to the simulation analysis of indoor test by finite element software ABAQUS, we analyze the influence of different bamboo spacing on the mechanical characters further, and the simulation results is close to the model experiment.(5) According to numerical simulation, we analyze the mechanical characters nodular piles under different soils.(6) According to numerical simulation,we analyze the reasonable ratio between bamboo spacing and dimmeter is 2.5 in this experiment.