Pile-formation sunken tube

Abstract

The invention discloses a pile forming apparatus of a sinking pipe pre-cast steel concrete bottom-expanded pipe, more particularly a pile forming sinking pipe, which is composed by a hollow pipe-shaped pipe body and at least two guide wings provided along circumferential direction, wherein position at inner side of bottom corresponding to the guide wings is provided with a positioning groove matching with a positioning iron foot of an excavation apparatus, upper part of the longitudinal cutaway view of the positioning groove is a wedged bevel, lower part matches with outer end part of the positioning iron foot; lower part and bottom outer wall of the pipe body are sleeved with sealing rings. Compared with prior art, the invention not only guarantees proportion relation between the pipe body and inner diameter of the bottom, but sufficiently utilizes the effective space of the guide wings to give enough depth to the positioning groove so that the positioning iron foot on the excavation bottom-expanded apparatus can easily get into the groove firmly and reliably with accurate positioning, so concentric degrees of the pile body and pedestal are enhanced and bearing force of single pile reaches the design standard; the invention not only can be used inland, but at the coastal regions with simple actualization.

Description

[0001] This application is a divisional application of the application number 200510047946.4, the application date is December 8, 2005, and the invention name is the pile-forming sinking pipe of the prefabricated steel concrete expanded bottom pile. technical field [0002] The invention relates to a pile-forming device of a prefabricated steel concrete expanded bottom pile by sinking tubes, in particular to a pile forming sinking tube of a prefabricated steel concrete expanded bottom pile. Background technique [0003] At present, in the pile foundation engineering of soft soil foundation, three kinds of cast-in-situ piles, prefabricated piles and large-diameter bored piles are generally used. Among them, the large-diameter bored pile has the highest bearing capacity, but its cost is the most expensive, the work efficiency is low, and the pollution is serious during construction. Therefore, it is usually only used in high-rise buildings with high bearing capacity requiremen...

AI Technical Summary

Problems solved by technology

The immersed tube is positioned with the excavating equipment with two "V"-shaped spiral grooves in cross-section. Only when the "V"-shaped spiral grooves have sufficient depth can the positioning be firm and reliable. The inner diameter of the bottom of the large immersed tube, and the inner diameter of the upper part should be kept larger than that of the lower part, and should be increased accordingly. Obviously, this is not advisable

If the upper and lower inner diameters remain unchanged, it will affect the smooth passage of the pile body in the immersed tube

And the current immersed tube is only suitable for use in the interior, and cannot be used in coastal areas, because when the metal pile head is taken out, a conical cavity is formed, there is a pressure difference between the outside of the tube and the inside of the tube, and the silt on the hard soil layer It is easy to enter into the conical cavity, so that the bottom expansion work cannot be carried out, and the use of immersed tubes in coastal areas is limited

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