An end-supported threaded soil-squeezing pile-forming equipment and a pile-forming construction method

Abstract

The invention discloses an end-supporting threaded soil-extruding pile forming equipment and a pile forming method, which can form a "hard bottom" at the bottom of the pile body by spraying cement slurry at the bottom of the pile body, increasing the resistance at the bottom of the pile body, The piercing of the bottom of the pile is effectively controlled; at the same time, since the section of the pile is a threaded shape after the pile is formed, the thread of the pile body and the soil thread on the side of the pile are tightly occluded, which can significantly increase the friction resistance around the pile, so the vertical bearing capacity of the single pile is limited. Significant improvement can effectively shorten the design pile length and reduce the project cost. In addition, the simultaneous completion of pile formation and pile body grouting can significantly shorten the construction period and improve construction efficiency; at the same time, during the pile formation process, the soil on the side of the pile is squeezed and densified, which can improve the performance of the soil around the pile and is beneficial to the pile. The long-term effect of the foundation also fundamentally avoids the waste slag being transported outside, the site mud pollution and treatment, and civilized construction is achieved.

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 soil-squeezing pile-forming equipment and a pile-forming construction method. Background technique [0002] The alluvial plains, river terraces, and coastal areas widely distributed in my country are mostly covered by thick to extremely thick Quaternary alluvial deposits, and the lithology of the formations is mostly muddy clay, soft clay, or loose silt or fine powder. The soft soil or soft soil composed of sand layer has a large distribution thickness and weak stratum. The pile foundations of railways, highways or housing construction projects built under such geological conditions are generally friction piles, and the pile ends cannot be placed on a hard bottom. Or on the bedrock, because the stratum around the pile is weak and there is no hard layer at the pile tip, the pile...

AI Technical Summary

Problems solved by technology

[0002] The alluvial plains, river terraces, and coastal areas widely distributed in my country are mostly covered by thick to extremely thick Quaternary alluvial deposits, and the lithology of the formations is mostly muddy clay, soft clay, or loose silt or fine powder. The soft soil or soft soil composed of sand layer has a large distribution thickness and weak stratum. The pile foundations of railways, highways or housing construction projects built under such geological conditions are generally friction piles, and the pile ends cannot be placed on a hard bottom. Or on the bedrock, due to the weak ground around the pile and no hard layer at the pile end, the pile diameter or pile length is often large, and the project investment is large.

[0003] At present, the existing types of pile foundation piles can be divided into three categories: artificial excavated piles, prefabricated driven piles and bored piles. Due to factors such as stratum conditions, groundwater development, and large pile length, it cannot be used; and the pile-forming technology of bored piles can be divided into construction techniques such as percussion drilling, rotary drilling, and auger (long helix and short helix). Pile-forming equipment, in which the percussion drill and the rotary drill are both soil-borrowing drilling, which are prone to collapse, liquefaction, or shrinkage holes when drilling into the weak strata around the pile. Clean up thoroughly, and at the same time, the spoil and mud will pollute the construction site; when the auger is used to form the hole, the soil is squeezed and drilled, which can improve the engineering properties of the soil around the pile, but it cannot improve the ground conditions below the pile tip, and the auger is limited by mechanical power , which restricts the depth or length of the pile

[0004] Therefore, the existing pile-forming equipment and its construction methods are difficult to meet the technical requirements or engineering needs of deep soft soil or soft soil foundation reinforcement

Images