An end-supported threaded core composite pile and its construction equipment and construction method

Abstract

The invention discloses an end-support type screw core composite pile and its construction equipment and construction method. The composite pile comprises a pile body, a bottom end support body and an inner core pile. The construction equipment includes pile forming equipment and pile pressing equipment; the drill pipe of the pile forming equipment is provided with a grouting channel connected with the grouting equipment, and the shaft is provided with several grouting holes connected with the grouting equipment, and the outer wall of the shaft A plurality of vanes are arranged from top to bottom, and the vanes are provided with grouting openings communicating with the grouting channels, and the drill bit is provided with nozzles correspondingly communicating with the grouting holes. During construction, the cement mortar is conveyed along the grouting hole through the drilling tool, and is sprayed out from the nozzle of the drill bit to form the bottom end support of the pile; then the grouting hole is closed, the injection channel is opened, and the cement mortar is discharged from the grouting port. After spraying out, the drill pipe is lifted at a constant speed to complete the construction of a single pile body, and finally the core pile is pressed into the completed pile body along the axial direction. The combined bearing pile single pile vertical bearing capacity of the invention is significantly improved, the design pile length can be shortened, and the engineering cost can be reduced.

Description

technical field [0001] The invention relates to the field of foundation treatment and construction of railways, highways, housing construction, etc., and specifically refers to an end-supported threaded core composite pile and its construction equipment and construction method. Background technique [0002] In my country's alluvial plains, river stages or coastal areas, Quaternary muddy clay, soft plastic to plastic state cohesive soil and loose to slightly dense silt or silty sand and other strata are distributed widely. 1. The thickness of the formation is large, and its engineering characteristics are mainly characterized by large void ratio, high compressibility, and low bearing capacity of the soil layer. The pile foundations of highways, railways or housing construction projects built under such geological conditions are generally friction piles, and the pile ends cannot be placed on hard bottom or bedrock. The strength is difficult to guarantee, and the settlement is ...

AI Technical Summary

Problems solved by technology

The pile foundations of highways, railways or housing construction projects built under such geological conditions are generally friction piles, and the pile ends cannot be placed on hard bottom or bedrock. It is difficult to guarantee the force, and it is also difficult to control the settlement

[0003] At present, the pile foundations of ordinary railways, highways, housing constructions or fields generally use cement-soil mixing piles for foundation treatment, which are characterized by low cost, wide application of ground conditions, and short construction time, but the disadvantage is that the bearing capacity of single piles is low. , when the foundation meets the soft soil layer, the settlement does not meet the design requirements. If the pile diameter or pile length is increased, not only will it be limited by construction equipment, but the investment will not meet the requirements; although ordinary cement-soil cored piles can increase a certain unit Pile bearing capacity, but the settlement problem cannot be solved, and because the surface of the core pile is smooth, the friction with the surrounding cement soil is insufficient, and it cannot effectively bear the upper pressure with the cement soil, and the improvement of the single pile bearing capacity is limited.

[0004] Therefore, the existing cement-soil mixing piles or ordinary cored piles are difficult to meet the technical requirements or engineering requirements for deep soft soil or soft soil foundation reinforcement

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