Study On Piles-soil Interaction Mechanism Of Double Rows– Small Diameter Bored Horizontal Bearing Piles And Its Application

This passage analyzed the best connection mode of the double rows-small diameter bored horizontal bearing piles top, and the allocation proportion on thrusting force of the double rows piles and the factors of influence design and so on based on the method of numerical simulation and indoor model test,as it also put forward the corresponding design calculation method. Obtains the researched achievements are as follows:(1) To establish modles of the double rows-small diameter bored horizontal bearing piles with different connection stiffness on piles'top, had compared and analysed the mechanical characteristics and the displacement on piles'top under various operating conditions, the conclusion is that the displacement and the max internal force of piles are smaller as the beam's stiffness is bigger. the influencing of increasing on beam's stiffness to extent of internal force and deformation is gradually declines when the beam's stiffness is enough.(2) Design an orthogonal experiment, the piles'top displacement and internal force as the index,sort every factor with primary and secondary,and select the optimal combination such as: the landslide thrust, the landslide's thickNess, the slope of sliding surface, the pile's diameter, the piles'spacing and row spacing etc. the pile's diameter is the bigger the better in the extent permitted of mechanical construction.(3)By the single factor analysis analyzing the changes of factors to piles'displacements and internal force influence:Whole stiffness big when rectangular arrangement; Double rows piles to share more evenly thrusting force as Crisscross decorates; Back row pile share of the thrusting force, as the increase of pile diameter; Pile spacing is better value interval with 4d ~ 6d; If due to the limitations of pile diameter, cannot bear,can be appropriately narrow pile spacing; Row spacing is optimal with 3d ~ 5d.(4) The pressure behind piles can be seen as the thrusting force piles borne, In this paper, the thrusting force allocation proportion was quantized treatment, Got allocation proportion of landslide thrusting force double rows piles borne on different condition. double row pile allocation proportion tend to equal sections as crisscross decorates;the landslide c andφvalue is larger; pile diameter less;the piles spacing take 4d ~ 6d; the row spacing take 3d ~ 5d.(5) Design an indoor landslide model and do model experiment aboat two model of double rows-small diameter bored horizontal bearing piles with different row spacing. Had measured piles' top displacement and piles' strain. Got piles' moment through the stress inverse calculation,It shown that the rules of piles' top displacement and piles' moment Correspond with the results of numerical simulation.(6) The double rows-small diameter bored horizontal bearing piles can be assumed to be flexible piles. Use of the single pile's rigidity coefficient calculating the rigidity coefficient with double rows piles, And then based on the rigidity coefficient with double rows piles and thrusting force calculating the displacements and rotation angle on double rows piles' top, again according to the single pile's rigidity coefficient and the rotation angle calculation of internal force of pile body.(7) Arrange a landslide as engineering examples, Design two solutions of rectangular cross-section cantilever piles and double rows-small diameter bored piles, draw the conclusion by selected two scheme: Adopt the scheme of double rows-small diameter bored piles, not only can bear bigger landslide thrusting force ,but also It can save 18% in project cost; save manpower and shorten the construction period when the holes were dug;. It consumes period is only artificial dig-hole 3/5 or so.