Novel precast pile and construction technology thereof

Abstract

A traditional prefabricated bamboo joint pile and a traditional threaded pile are improved, a grouting exhaust hole is formed in the protruding part of the pile, a traditional static pressure pile sinking or hammering pile sinking technology is adopted in the pile sinking technology, after pile sinking is finished, a flow state curing material is poured from the grouting exhaust hole, and the whole technology is completed after the flow state curing material is hardened. Compared with a traditional non-protruding pipe pile prefabricating technology, the bearing capacity of the pile can be greatly improved, compared with a static drilling and root planting bamboo joint pile technology, the construction steps are reduced, the construction period is shortened, and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a precast pile type and its construction process, and relates to the pile foundation engineering in the fields of building, municipal administration, traffic and the like which have requirements on vertical bearing capacity. BACKGROUND

[0002] The pile foundation can be divided into precast pile and cast-in-place pile according to the construction method. The common precast pile in the market is solid or hollow pile with circular or rectangular cross section. In recent years, some bamboo joint piles and screw piles with protrusions on the cross section have appeared. The vertical bearing capacity of the common precast pile without protrusion mainly depends on the bearing capacity of the pile end and the friction force of the pile side. For the pile with protrusion, the protrusion part changes the part of the friction force on the pile side into pressure, thereby greatly improving the lateral bearing capacity of the pile. Compared with the common precast pile without protrusion, the bamboo joint pile and the screw pile with the same outer diameter save the material, and the vertical bearing capacity of the pile is also greatly improved, and the comprehensive cost is low. However, for the pile with protrusion, the construction is not as convenient as the common precast pile without protrusion. For example, the driving sinking method, such as static pressure pile, hammer sinking pile, vibration sinking pile, the cavity is formed between the pile and the soil, especially the soil under the bamboo joint and the screw pile. For the static drilling and planting method, the hole needs to be drilled in advance, and then the pile is planted. The construction process is more complex than the driving sinking process. The drilling cost is high, the total construction time is long, and the comprehensive cost is also not low. SUMMARY

[0003] The present application utilizes the high vertical bearing capacity of the precast pile with protrusion (such as the bamboo joint pile and the screw pile with lateral protrusion), improves the pile type and the construction process, sets the grouting and exhaust hole at the protrusion part of the precast pile, adopts the driving sinking method (static pressure pile, hammer sinking pile, vibration sinking pile), and then fills the liquid solidification material through the air return hole after the pile is sunk. The whole sinking process is completed. Compared with the traditional precast pile without protrusion, the bearing capacity is higher under the condition of the same material. Compared with the static drilling and planting method, the liquid solidification material is filled after being directly driven without pre-drilling. The construction steps are less, the construction period is short, the bearing capacity of the liquid solidification material under pressure is much larger than that of the common soil, the liquid solidification material fills the gap between the pile and the soil, and the rough bonding surface is formed between the pile and the soil, thereby further improving the lateral resistance of the pile.

[0004] The present application has the characteristics of saving material, high pile bearing capacity, simple and fast construction, short construction period and low comprehensive cost.

[0005] The new pile body is a precast pile. The pile body 1 can be circular or rectangular, can be hollow pile, or can be solid pile, and the pile length is L.

[0006] The lower end of the pile adopts an enlarged head 2. The diameter D (or side length A, B) of the enlarged head 2 is consistent with the outer expansion dimensions of the upper protruding bamboo joint 3 and spiral 3 (the figure only shows the bamboo joint). The function of the enlarged head 2 is to increase the area of ​​the pile end, improve the bearing capacity of the pile end, increase the stiffness of the pile end, and at the same time, it will squeeze the soil 7 between the piles when the pile is driven, so as to ensure that the upper protruding part 3 will not further cut the soil 7 on the side of the pile during the pile driving.

[0007] Bamboo joint 3, spiral 3 (the illustration only shows bamboo joint) protrusions open grouting and venting holes 5 (6), the holes can be in the form of openings 5 ​​or in the form of notches 6, the number of openings is 1 to 12 (the illustration only shows 4), the number of notches is 1 to 12 (the illustration only shows 4).

[0008] The new pile driving method is consistent with the traditional precast pile driving method, and can be carried out by static pressure driving or by hammer driving. Figure 4 (S1, S2).

[0009] Enlarged heads are not required for non-first-section piles, and the connection between multi-section piles is the same as that of traditional piles.

[0010] After the pile is driven to the design elevation, a fluidized solidification material 8 is injected through the grouting and venting holes on the side of the pile. The material can be cement soil, concrete, mortar, water glass, or other fluidized solidification materials. Figure 4 in S3, S4).

[0011] The injection method for fluidized solidified materials can be pressure grouting through a conduit. Figure 4 (S4 left side), or a funnel-shaped tube can be used to infuse 10 Figure 4 (S4 right side), or directly inject until the grout fills all the voids in the pile soil ( Figure 4 in S4).

[0012] After the equivalent fluidized solidification material solidifies, all processes are completed. Figure 4 S5). Attached Figure Description Figure 1 Elevation and sectional views of a new type of precast pile with a circular cross-section; Figure 2 Elevation and sectional views of the rectangular cross-section of the new type of precast pile; Figure 3 A schematic diagram of the ventilation backflow hole for a new type of precast pile; Figure 4 This is a schematic diagram of the construction process of driving a new type of precast pile.

Claims

1. A precast pile type and construction process, characterized in that, The pile is sunk by static pressure pile, hammer pile or vibration pile, and the new type of prefabricated pile is a pile with protrusions, including bamboo joint pile and screw pile, etc., wherein the first section of the pile has an enlarged head 2, and the diameter or side length of the enlarged head 2 is the same as that of the pile at the bamboo joint or screw thread position. The protruding part 3 at the bamboo joint or screw thread position is provided with a grouting exhaust hole 4, and after the pile is sunk, the grouting exhaust hole 4 can be filled with flowable solidified material 8 to complete the pile foundation construction.

2. The new type of prefabricated pile and its construction process according to claim 1, wherein the length d1 of the enlarged head 2 at the lower end of the first section of the pile is 0.5-3 times the diameter D or the maximum side length A, B of the enlarged head, and the second section of the pile can not be provided with an enlarged head.

3. The new type of prefabricated pile and its construction process according to claim 1, wherein the grouting exhaust hole 4 is added at the protruding position 3 of the pile, and the hole can be in the form of a hole 5 or a notch 6, and the number of holes is 1-12, and the number of notches is 1-12. The hole 5 or the notch 6 is used to ensure that the flowable solidified material 8 can be filled after the pile is sunk.

4. The new type of prefabricated pile and its construction process according to claim 1, wherein after the pile is sunk to the design elevation, the flowable solidified material 8 is filled through the grouting exhaust hole 4 on the side of the pile, and the material can be flowable solidified soil, cement soil, concrete, mortar, water glass and other flowable solidifiable materials.

5. The new type of prefabricated pile and its construction process according to claim 1, wherein the flowable solidified material filling method can be pressure grouting 9 through a pipe, funnel pipe pouring 10, or direct pouring.

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