A precast pile capable of preventing pile explosion during pile sinking

Abstract

The application discloses a precast pile capable of preventing pile explosion during pile sinking, which comprises a pile body, a central hole in the pile body, the top end of the central hole being located in the pile body and the bottom end forming an opening at the bottom of the pile body; the pile body is formed by large sections with relatively large cross sections and small sections with relatively small cross sections along the length direction of the pile body, and the outer peripheral wall of each section is formed with a protruding part protruding outward at the part corresponding to the large section, so that the air layer with gradually reduced thickness under the rebound characteristics of the soil is formed between the outer peripheral wall of each section and the surrounding soil during pile sinking; the pile body is provided with at least one pressure relief hole communicated from the hole wall of the central hole to the outer peripheral wall of the small section, which is used for sinking the soil into the central hole and discharging the high-pressure gas formed in the central hole to the air layer outside the pile body during pile sinking. The application has the beneficial effect of protecting the precast pile and avoiding damage of the precast pile during pile sinking.

Description

TECHNICAL FIELD

[0001] The present application relates to a precast pile, belonging to the optimization design of precast pile prone to pile explosion when sinking. BACKGROUND

[0002] There are three types of precast piles, namely solid pile, hollow pile and semi-hollow pile, wherein the semi-hollow pile is provided with a central hole in the pile body, the top end of the central hole is in the pile body, and the bottom end of the central hole forms an opening at the bottom end of the pile body. The semi-hollow pile takes into account the saving of materials and structural strength. However, during the process of sinking the pile, the soil will gradually press into the central hole from the bottom end of the central hole, and the amount of soil pressed in will gradually increase as the pile sinking proceeds, and the air in the central hole will be gradually compressed during this process, thereby the danger of pile explosion due to the high air pressure in the central hole of the pile body will occur. SUMMARY

[0003] The purpose of the present application is to provide a precast pile that can prevent pile explosion when sinking, which plays a role in protecting the precast pile and avoiding damage during the sinking process.

[0004] The present application is achieved by the following technical solutions.

[0005] A precast pile that can prevent pile explosion when sinking, comprising a pile body, a central hole located in the pile body, the top end of the central hole being located in the pile body and the bottom end forming an opening at the bottom of the pile body;

[0006] The pile body is formed by large segments with relatively large cross sections and small segments with relatively small cross sections along the length direction of the pile body, and each outer peripheral wall of the pile body is formed with a protruding portion protruding outward at the portion corresponding to the large segment, so that an air layer with a thickness gradually reduced under the effect of soil resilience characteristics is formed between each outer peripheral wall of the small segment and the surrounding soil during pile sinking;

[0007] The pile body has at least one pressure relief hole, which is connected from the hole wall of the central hole to the outer peripheral wall of the small segment, for the soil to press into the central hole during pile sinking and for the high-pressure gas formed in the central hole to be discharged to the air layer outside the pile body.

[0008] As a further improvement of the present application, the pile body is formed with an air path communication groove extending along the length direction of the pile body between any two adjacent protruding portions of the large segment, and the side walls corresponding to the adjacent two protruding portions form at least part of the groove wall of the air path communication groove, and the space of the air path communication groove is suitable for not being completely filled with soil during pile sinking, so as to connect the air layers corresponding to each small segment on the pressure relief air path.

[0009] As a further improvement of the present application, the small segment near the top end of the central hole on the pile body is arranged with a pressure relief hole.

[0010] As a further improvement of the present application, the pressure relief hole is arranged in a direction away from the center hole and towards the gas passage communication groove.

[0011] As a further improvement of the present application, the pressure relief hole comprises a necked-down section and a maintained section, the necked-down section has a gradually reduced diameter in the direction of pressure relief, and the inner opening of the pressure relief hole in the center hole wall is formed in the necked-down section, the maintained section has a constant diameter in the direction of pressure relief.

[0012] As a further improvement of the present application, the pressure relief hole further comprises a flared section connected to the maintained section, the flared section has a gradually increased diameter in the direction of pressure relief, and the outer opening of the pressure relief hole in the outer wall of the small section is formed in the flared section.

[0013] As a further improvement of the present application, the pressure relief hole is arranged in an upward direction from the inner opening in the center hole wall to the outer opening in the outer wall of the small section.

[0014] As a further improvement of the present application, the hole wall of the pressure relief hole is a smooth hole wall after polishing.

[0015] As a further improvement of the present application, the pile body has at least one dredging hole, the dredging hole is connected from the hole wall of the center hole to the groove wall of the gas passage communication groove, so that the high-pressure gas in the center hole is discharged when the pile is sunk, and the gas passage of the gas passage communication groove is dredged.

[0016] As a further improvement of the present application, the dredging hole is arranged in a large section close to the top end of the center hole.

[0017] As a further improvement of the present application, the outer opening of the dredging hole on the gas passage communication groove has an elongated shape extending transversely.

[0018] As a further improvement of the present application, at least one gas guide groove is formed in the groove wall of the gas passage communication groove, the gas guide groove is connected to the outer opening of the dredging hole, and is used to expand the dredging range of the dredging hole.

[0019] As a further improvement of the present application, each of the upper and lower sides of the outer opening is connected to at least one gas guide groove, and the gas guide groove extends vertically.

[0020] As a further improvement of the present application, the left and right end edges of the outer opening of the dredging hole are at the same distance from the corresponding two groove edges of the gas passage communication groove.

[0021] As a further improvement of the present application, the cross-sectional shape of the dredging hole gradually changes from the inner opening hole shape in the center hole wall to the outer opening hole shape in the groove wall of the gas passage communication groove.

[0022] As a further improvement of the present application, the sectional area of the through hole gradually decreases from the inner hole opening on the wall of the central hole to the outer hole opening on the wall of the air passage communication groove.

[0023] As a further improvement of the present application, the wall of the through hole is a smooth wall after polishing.

[0024] As a further improvement of the present application, the side walls of the two adjacent protrusions form the complete wall of the air passage communication groove, and the two side walls are connected and the connection forms a chamfer structure.

[0025] As a further improvement of the present application, the side walls of the two adjacent protrusions form the complete wall of the air passage communication groove, and the two side walls are a continuous arc-shaped wall.

[0026] As a further improvement of the present application, the intersection of the outer peripheral wall of the protrusion and the left and right two side walls forms a chamfer structure.

[0027] As a further improvement of the present application, the intersection of the outer peripheral wall of the protrusion and the upper and lower two side walls forms a chamfer structure, and the intersection of the upper and lower two side walls of the protrusion and the outer peripheral wall of the corresponding small segment forms a chamfer structure.

[0028] As a further improvement of the present application, the upper and lower two side walls of the protrusion are inclined to the horizontal plane, and are adapted to form an obtuse angle between the upper and lower two side walls of the protrusion and the outer peripheral wall of the corresponding protrusion and the outer peripheral wall of the small segment.

[0029] As a further improvement of the present application, the central hole divides the pile body into a solid portion and a hollow portion, and a peripheral steel cage is arranged in the pile body, and the coverage range of the peripheral steel cage includes the solid portion and the hollow portion.

[0030] As a further improvement of the present application, the peripheral steel cage includes a plurality of peripheral prestressed steel bars extending along the length direction of the pile body and distributed in the circumferential direction, and a peripheral tie bar clamping and binding the plurality of peripheral prestressed steel bars together, and the connection points of the peripheral tie bar corresponding to each peripheral prestressed steel bar are distributed along the peripheral prestressed steel bar.

[0031] As a further improvement of the present application, the peripheral prestressed steel bars are arranged at equal intervals along the boundary of the cross section edge of the small segment.

[0032] As a further improvement of the present application, the boundary defined by the cross section edge of the small segment is provided with peripheral prestressed steel bars at the corners.

[0033] As a further improvement of the present application, an inner steel cage is further arranged in the pile body, and the inner steel cage is located in the inner periphery of the peripheral steel cage and covers the solid portion.

[0034] As a further improvement of the present application, the inner cage includes a plurality of inner prestressed steel bars extending along the length of the pile body and distributed circumferentially, an inner tie bar clamping and binding the plurality of inner prestressed steel bars together, the inner tie bar being spacedly distributed along the inner prestressed steel bars corresponding to the connection points of each outer prestressed steel bar.

[0035] As a further improvement of the present application, the plurality of inner prestressed steel bars are arranged around the center of the cross section of the pile body at equal intervals.

[0036] As a further improvement of the present application, the inner tie bar clamps the plurality of inner prestressed steel bars in a ring shape.

[0037] As a further improvement of the present application, the central hole and the central axis of the pile body are coaxially arranged.

[0038] As a further improvement of the present application, the pile body is in the form of a rectangular structure, and the central hole is in the form of a cylindrical hole.

[0039] As a further improvement of the present application, the central hole divides the pile body into a solid part and a hollow part, and the length of the solid part accounts for 3 / 100~1 / 2 of the length of the pile body.

[0040] As a further improvement of the present application, the pile body includes a plurality of unit piles, and the plurality of unit piles are connected end to end to form the pile body.

[0041] The present application has the following beneficial effects:

[0042] When the pile is being sunk, the soil is continuously pressed into the central hole from the opening at the bottom end of the central hole, and the air in the central hole is rapidly compressed, resulting in a sharp increase in pressure. At this time, the high-pressure gas can be discharged in time to the air layer outside the pile body through the pressure relief hole. Through this active pressure relief mechanism, the pressure peak in the central hole is effectively controlled, thereby reducing the risk of the pile wall being burst due to the excessively high pressure of the gas inside the pile, i.e., the risk of the pile being burst. BRIEF DESCRIPTION OF DRAWINGS

[0043] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, which are provided to assist in understanding the purposes and advantages of the present application, and of which:

[0044] Figure 1 is a sectional view of the pile body in the state of sinking in the embodiment 1;

[0045] Figure 2 is a partial view of the external structure of the pile body in the embodiment 1;

[0046] Figure 3 is a cross-sectional view of the large segment in the state of sinking in the embodiment 1;

[0047] Figure 4This is a cross-sectional schematic diagram of a small segment with a pressure relief hole in Embodiment 1;

[0048] Figure 5 This is a cross-sectional schematic diagram of the gas passage connecting groove in the first embodiment of implementation method 1;

[0049] Figure 6 This is a cross-sectional schematic diagram of the gas passage connecting groove in Implementation Method 1 under the second implementation method;

[0050] Figure 7 This is a cross-sectional view of the protrusion and segment in Embodiment 1 under the first embodiment.

[0051] Figure 8 This is a cross-sectional view of the protrusion and segment in embodiment 1 under the second embodiment;

[0052] Figure 9 A schematic diagram of the cross-section of the solid part in Case 1;

[0053] Figure 10 A schematic diagram of the cross-section of the hollow part in Case 1;

[0054] Figure 11 A cross-sectional view of the large segment with unblocking holes in Case 2;

[0055] Figure 12 This is a partial structural diagram of the large segment and the unblocking hole in Case 2. Detailed Implementation

[0056] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0057] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0058] Implementation Method 1: This implementation method illustrates a precast pile that can effectively prevent the risk of pile bursting due to excessive air pressure in the central hole during pile driving. (Refer to...) Figures 1-4The prefabricated pile mainly comprises a pile body 1 and a central hole h1 located in the pile body 1, the top end of the central hole h1 is closed inside the pile body 1, and the bottom end forms an opening at the bottom of the pile body 1. The pile body 1 is composed of large segments 11 with relatively large cross sections and small segments 12 with relatively small cross sections which are alternately connected along the length direction of the pile body 1. Specifically, on each outer peripheral wall of the pile body 1, a convex portion c is formed outward corresponding to each large segment 11, so that during the pile sinking process, due to the cross section of the small segment 12 being within the range of the cross section of the large segment 11, the large segment 11 pushes the soil away, and the soil has a rebounding characteristic, so that an air layer r1 around the small segment 12 with a gradually decreasing thickness over time is naturally formed between the outer peripheral wall of the small segment 12 and the surrounding soil. The pile body 1 is provided with at least one pressure relief hole h2 which directly penetrates and communicates from the inner wall of the central hole h1 to the outer peripheral wall of a certain small segment 12. When the pile sinking is carried out, the soil is continuously pressed into the central hole h1 from the opening at the bottom end of the central hole h1, and the air in the central hole h1 is rapidly compressed, resulting in a dramatic increase in pressure; at this time, the high-pressure gas can be discharged in time to the air layer r1 outside the pile body 1 through the pressure relief hole h2. The prefabricated pile of the embodiment can achieve the mechanism of active pressure relief by setting the pressure relief hole h2, and the pressure peak inside the central hole h1 is effectively controlled, thereby reducing the risk of bursting the pile wall due to the excessive gas pressure inside the pile body 1, i.e. the risk of burst pile.

[0059] In the present embodiment, in the large section 11 part of the pile body 1, between any two adjacent convex parts c, a gas path communication groove r2 extending along the length direction of the pile body 1 is formed, at least part of the groove wall is directly formed by the side wall of the two adjacent convex parts c opposite to each other. In other words, the gas path communication groove r2 is similar to the groove structure formed by cutting the edges of a square column. During the pile sinking process, due to the relatively narrow groove opening of the gas path communication groove r2, it can effectively block the large block or dense soil from entering the groove. Therefore, the space occupied by the gas path communication groove r2 will not be completely filled by the surrounding soil, and usually part of the space will be reserved or only be partially filled by relatively loose soil. This incompletely filled state makes the gas path communication groove r2 form a continuous longitudinal channel between the adjacent large sections 11. The gas path communication groove r2 connects the originally relatively independent annular air layers r1 formed around each small section 12 to each other in the pressure relief gas path. This connection expands the space range where the high-pressure gas can be released by the pressure relief hole h2. On the one hand, the pressure difference between the inside of the pile body 1 (central hole h1) and the outside of the pile body 1 (communicated air layer r1) can be maintained at a more favorable level for rapid pressure relief, improving the pressure relief efficiency. On the other hand, it avoids the situation that the high-pressure gas is only released into the air layer r1 of the small section 12 corresponding to a certain pressure relief hole h2, causing the local area to have too high pressure, and then strongly extruding the surrounding soil, resulting in an abnormal increase in the pile sinking resistance, and ensuring the stability of the pile sinking process.

[0060] In the present embodiment, the pressure relief hole h2 is arranged on the outer peripheral wall of the small section 12 near the top end of the central hole h1 on the pile body 1. The soil is gradually pressed into the central hole h1 from the opening at the bottom end of the central hole h1 as the pile body 1 sinks. The area near the top end of the central hole h1 is the last position to be reached and filled by the soil. Therefore, arranging the pressure relief hole h2 in this area can avoid the situation that the pressure relief hole h2 is covered, buried or blocked by the soil in the central hole h1 too early during the pile sinking process, so as to ensure that the pressure relief hole h2 can be unobstructed during the entire pile sinking process and continuously play its pressure relief function.

[0061] In the present embodiment, the outer opening of the pressure relief hole h2 on the outer peripheral wall of the small section 12 is arranged near the gas path communication groove r2. Since the gas path communication groove r2 is a longitudinal channel that communicates the air layers r1 of each small section 12, arranging the outer opening of the pressure relief hole h2 near it can shorten the path distance of the high-pressure gas after being released from the pressure relief hole h2 to the gas path communication groove r2, reduce the resistance of gas flow, and make the high-pressure gas more directly and quickly enter this connected pressure relief network, so as to more efficiently disperse into a wider air layer r1 space, improving the flow and overall efficiency of the pressure relief process.

[0062] In the present embodiment, the pressure relief hole h2 comprises a necking section h21 and a holding section h22 which are connected to each other, the necking section h21 is arranged at a section close to the inner wall of the central hole h1, along the direction of the gas discharge flow, the caliber of this section is gradually reduced, the inner hole of the pressure relief hole h2 on the hole wall of the central hole h1 is located at the starting end of this necking section h21, and the holding section h22 is arranged next to the necking section h21, along the direction of the gas flow, the caliber of this section remains unchanged. The arrangement of the necking section h21 and the holding section h22 utilizes the Venturi effect: when the high-pressure gas enters the necking section h21 with a relatively large caliber from the central hole h1 with a relatively large caliber, the flow rate of the gas will increase, and after the high-speed gas flow enters the holding section h22, the flow rate remains unchanged due to the constant caliber of this section. This high-speed flow state reduces the energy loss during the gas flow, effectively improves the speed and flow rate of the gas discharged outward through the pressure relief hole h2, so that more high-pressure gas can be discharged per unit time, further enhancing the ability of the pressure relief hole h2 to reduce the gas pressure in the central hole h1, and improving the reliability of the explosion-proof pile.

[0063] In the present embodiment, after the holding section h22 of the pressure relief hole h2, an interconnected flared section h23 is added, along the direction of the gas discharge flow, the caliber of this section is gradually increased, and the outer hole of the pressure relief hole h2 on the outer peripheral wall of the small section 12 is located at the end of this flared section h23. When the high-speed gas flow from the holding section h22 enters the gradually expanding space, the flow rate will naturally decrease, and the gas flow will tend to diffuse and stabilize, so that the high-pressure gas avoids forming a jet flow at the hole that can disturb the stability of the air layer r1 when it leaves the pressure relief hole h2 and enters the outer peripheral air layer r1 of the pile body 1.

[0064] In the present embodiment, the hole axis of the pressure relief hole h2 is not horizontal or downward, but is inclined upward as a whole, with the inner hole on the hole wall of the central hole h1 pointing to the outer hole on the outer peripheral wall of the small section 12. As the pile body 1 sinks, the soil is pressed into the central hole h1 from bottom to top, causing the air in the central hole h1 to be compressed and gathered upward from bottom to top. The main "collection area" and "pressure source" of the high-pressure gas is located in the upper region of the central hole h1. By arranging the pressure relief hole h2 to be inclined upward from inside to outside, the inner hole of the pressure relief hole h2 is more easily contacted by the high-pressure gas gathered in the upper part of the central hole h1, and the flow direction of the gas in the pressure relief hole h2 also conforms to the natural gathering and upward movement tendency of the gas in the central hole h1, reducing the resistance of the gas flowing to the inlet of the pressure relief hole h2, and facilitating the smooth entry of the high-pressure gas into the pressure relief hole h2 and being discharged, thereby optimizing the pressure relief path.

[0065] In the present embodiment, the hole wall of the pressure relief hole h2 is polished, and becomes a smooth hole wall, thereby reducing the frictional resistance generated between the gas and the hole wall when the gas flows through the hole channel of the pressure relief hole h2, the flow rate is maintained or increased, the gas flow through the pressure relief hole h2 per unit time is also increased accordingly, the pressure relief efficiency is improved, and the pressure relief hole h2 can discharge the high-pressure gas in the center hole h1 more quickly and smoothly.

[0066] In the present embodiment, with reference to Figure 5 , the side walls corresponding to the two adjacent convex parts c (i.e. the two side surfaces facing each other) constitute the complete groove wall of the gas passage communication groove r2. In the first embodiment, a chamfer structure m1 is formed at the connection of the two side walls (i.e. at the corner of the groove). First, the chamfer structure m1 can significantly enhance the structural strength of the corner, and eliminate the stress concentration point, so that the area is not prone to cracks or damage due to stress concentration when the pile bears complex soil pressure and structural load, thereby improving the local and overall structural reliability of the pile body 1. Second, the chamfer also facilitates mold manufacturing and demolding, improving production efficiency.

[0067] In the present embodiment, with reference to Figure 6 , the side walls corresponding to the two adjacent convex parts c constitute the complete groove wall of the gas passage communication groove r2. In the second embodiment, the two side walls form a continuous and smooth arc-shaped wall g (for example, forming a U-shaped or semicircular groove bottom). The smooth arc-shaped wall g eliminates any corners at the corner of the groove wall, optimizing the shape of the flow channel inside the gas passage communication groove r2. For the gas flow in the groove, the smooth and continuous arc-shaped wall g reduces the local resistance of the gas flow, and the gas flow can flow smoothly along the curved surface, avoiding energy loss phenomena such as vortex flow and flow separation at the corner.

[0068] In the present embodiment, with reference to Figure 5 and Figure 6 , specifically, a chamfer structure m2 is formed at the intersection of the outer peripheral wall of the convex part c (i.e. the outermost wall surface of the large segment 11) and its left and right two side walls (i.e. the wall surface adjacent to the adjacent convex part c or the gas passage communication groove r2) (i.e. the position of the formed edge line). During pile sinking, the outer peripheral wall and the side wall of the convex part c bear the main extrusion and friction of the soil, and the sharp corners are prone to breakage due to stress concentration. The chamfer enhances the strength, toughness and breakage resistance of these connection parts, and the chamfered edge is relatively smooth, which can reduce the severe shearing and disturbance to the surrounding soil during the pile sinking process, possibly reduce the local pile sinking friction resistance, and also be beneficial to protect the edge of the convex part c itself and reduce wear and tear.

[0069] In the present embodiment, in the first specific implementation, with reference to Figure 7At the intersection of the outer peripheral wall of the protruding part c and its upper side wall and lower side wall (i.e. the upper and lower edges), chamfered structures m3 are formed. In addition, at the intersection of the upper side wall of the protruding part c and the outer peripheral wall of the corresponding small segment 12 (i.e. the transition edge between the upper end of the large segment 11 and the small segment 12), and at the intersection of the lower side wall of the protruding part c and the outer peripheral wall of the corresponding small segment 12 (i.e. the transition edge between the lower end of the large segment 11 and the small segment 12), chamfered structures m3 are also formed. The chamfering of these locations (the top and bottom edges of the protruding part c and the transition edges) eliminates the risk of stress concentration caused by sharp corners, enhances the impact resistance and fracture resistance of these critical transition areas, improves the structural reliability of the pile body 1 under pile impact load, and more gently guides the displacement and backfill of the soil when the pile body 1 changes segments (from a large segment 11 to a small segment 12 or vice versa), reducing the local intense extrusion or shearing of the soil at this point, which helps to reduce the peak and fluctuation of the pile resistance, making the pile sinking process more stable.

[0070] In this embodiment, the second specific implementation is described with reference to Figure 8 , specifically, the upper and lower side walls of the protruding part c are inclined to the horizontal plane and inclined outwardly from the pile body 1, the corner n formed by the intersection of the outer peripheral wall of the protruding part c and its upper side wall is an obtuse angle, and similarly, the corner n formed by the intersection of the outer peripheral wall of the protruding part c and its lower side wall is also an obtuse angle. When the pile body 1 sinks and the protruding part c of the large segment 11 contacts and extrudes the soil, this open angle provides a more gentle "guide slope" for the soil. When the soil is extruded, it is easier to slide upward (for the lower side wall) or downward (for the upper side wall) along this slope and be extruded, rather than being violently sheared by the vertical wall, thereby reducing the degree of damage to the soil structure and the frictional resistance generated between the soil and the pile wall. At the same time, this obtuse angle is also conducive to the soil being more effectively backfilled around the small segment 12 after the pile is sunk to form a stable air layer r1 and improve the interaction force distribution between the soil and the pile body 1.

[0071] In this embodiment, reference is made to Figure 9 and Figure 10 Due to the presence of the central hole h1, the pile body 1 is divided into solid and hollow parts in cross section, and a peripheral steel cage is provided in the pile body 1, with the spatial coverage of the steel cage including the solid and hollow parts. The peripheral steel cage provides overall and continuous skeleton reinforcement for the entire pile body 1, ensuring that the pile body 1 has sufficient structural integrity and carrying capacity when subjected to pile impact force and complex soil pressure, effectively preventing the pile body 1 from cracking or breaking.

[0072] In the present embodiment, the peripheral reinforcement cage, more specifically, comprises a plurality of peripheral prestressed steel bars 21 extending along the length of the pile body 1 and distributed circumferentially in the peripheral region of the pile body 1 to provide the main longitudinal tensile strength, and a peripheral stirrup 22 to bind and fix the plurality of peripheral prestressed steel bars 21 together. The peripheral stirrup 22 is wrapped around the periphery of the plurality of peripheral prestressed steel bars 21 in a clamping manner, and the connection points between the peripheral stirrup 22 and each peripheral prestressed steel bar 21 are distributed at intervals along the length of the peripheral prestressed steel bar 21. This interval distribution of the peripheral stirrup 22 connection mode ensures the positional stability of the peripheral prestressed steel bars 21 in the longitudinal direction of the pile body 1, preventing them from shifting or dispersing during the concrete pouring process, and the peripheral stirrup 22 provides effective hoop restraint force to tightly integrate the peripheral prestressed steel bars 21 into a whole framework.

[0073] In the present embodiment, the arrangement of the peripheral prestressed steel bars 21 is based on the boundary defined by the cross-sectional edges of the small segments 12 in the pile body 1, i.e. these peripheral prestressed steel bars 21 are arranged along the outer contour line of the cross section of the small segment 12, and are distributed at equal intervals. The peripheral prestressed steel bars 21 are arranged at the outermost side, which can most effectively provide bending resistance, and the equal interval distribution ensures that the strength and restraint force provided by the steel bars are uniform in the circumferential direction of the pile body 1, avoiding the problem of insufficient local strength. Since the cross-sectional size of the small segment 12 determines the outermost size of the pile body 1 at this segment, arranging the steel bars at equal intervals along the boundary enhances the structural strength of the outermost part of the pile body 1.

[0074] In the present embodiment, peripheral prestressed steel bars 21 are arranged at the corners of the boundary defined by the cross-sectional edges of the small segment 12. The small segment 12 is the segment with the smallest cross-sectional size of the pile body 1, and the corners are prone to micro-cracks caused by pile impact load. Arranging high-strength peripheral prestressed steel bars 21 at the corners is equivalent to embedding a framework in the stress concentration area.

[0075] In the present embodiment, an inner reinforcement cage is also provided in the pile body 1, which is located in the inner periphery of the peripheral reinforcement cage and has a spatial coverage range limited to covering the solid part of the cross section of the pile body 1. The solid part bears the huge lateral pressure generated by the soil pressing into the central hole h1 and the pile hammer impact force during pile sinking, and the inner reinforcement cage can provide additional structural strength to the solid part. The inner reinforcement cage and the peripheral reinforcement cage work together to ensure the structural integrity and durability of the entire pile body 1 during pile sinking and subsequent use.

[0076] In the present embodiment, for the inner cage, more specifically, the inner cage mainly comprises a plurality of inner prestressed steel bars 31 and a plurality of inner stirrups 32, both of which have similar functions as the outer prestressed steel bars 21 and the outer stirrups 22, which will not be repeated again.

[0077] In the present embodiment, the plurality of inner prestressed steel bars 31 are arranged around the center of the cross section of the pile body 1, and the circumferential intervals between them are equal, ensuring that the longitudinal strength and restraint force are uniformly distributed in the circumferential direction of the solid section.

[0078] In the present embodiment, the inner stirrups 32 are in the form of a ring and are wrapped around the plurality of inner prestressed steel bars 31, which can exert more uniform radial restraint force on the inner wrapped inner prestressed steel bars 31 and concrete.

[0079] In the present embodiment, the central hole h1 is coaxial with the overall central axis of the pile body 1, ensuring that the mass distribution of the pile body 1 is balanced and symmetrical relative to the central axis, avoiding additional bending moments or torsional stresses due to the eccentricity of the center of gravity of the pile body 1, and improving the structural stability of the pile body 1 during pile sinking.

[0080] In the present embodiment, the pile body 1 is in the form of a rectangular body structure (such as a square column), and the central hole h1 inside the pile body 1 is in the form of a cylindrical hole.

[0081] In the present embodiment, the length of the solid section accounts for a proportion of the total length of the pile body 1 in the range of 3 / 100 to 1 / 2.

[0082] In the present embodiment, the pile body 1 can be a unitary structure or formed by connecting a plurality of unit piles end to end. If a plurality of unit piles are provided, the size and weight of individual components can be reduced, thereby reducing transportation difficulties. In addition, shorter unit piles are easier to ensure manufacturing precision and improve the overall quality of the pile body 1.

[0083] Embodiment 2:

[0084] The present embodiment shows a precast pile, which is described with reference to Figure 11 and Figure 12 and in combination with Figures 1-10In this embodiment, in order to deal with the problem of possible local blockage of the air path communication groove r2 during the pile sinking process, ensure the stability and reliability of the pressure relief function of the air layer r1 connected thereto, and compared with the first embodiment, a dredging mechanism is added in the technical solution. Specifically, at least one dredging hole h3 is provided on the pile body 1, which extends through the pile body 1 from the hole wall of the central hole h1 and finally connects to the groove wall of the air path communication groove r2. When high-pressure gas is formed in the central hole h1 during the pile sinking process, this part of high-pressure gas can not only be discharged to the air layer r1 through the pressure relief hole h2, but also be guided and sprayed at high speed into the air path communication groove r2 through the dredging hole h3. Although the air path communication groove r2 is not easy to be completely filled with compacted soil in design, under complex actual geological conditions, there may be a large amount of loose soil accumulated in the groove, forming a local blockage point and hindering the gas flow between adjacent air layers r1. After the high-pressure gas is sprayed into the air path communication groove r2 from the dredging hole h3, it can effectively blow and disturb these locally accumulated loose soil, push them away or scatter them, thereby dredging the partially blocked air path communication groove r2 and restoring or maintaining its ability to establish an effective pressure relief air path between the air layers r1 of each small section 12. This is equivalent to adding a "self-cleaning" guarantee to the pressure relief system, ensuring the long-term unobstructedness of the pressure relief channel and the system reliability.

[0085] In this embodiment, the dredging hole h3 is arranged on the large section 11 of the pile body 1 near the top end of the central hole h1 (i.e. near the top end of the central hole h1), which has a similar effect as the selection of the position of the pressure relief hole h2, which will not be described here.

[0086] In this embodiment, the outer aperture of the dredging hole h3 on the groove wall of the air path communication groove r2 has an elongated shape (such as a slit, an oval long axis horizontally, a long strip, etc.), so that when the high-pressure gas is sprayed from the dredging hole h3, the coverage range of the jet flow is widened in the cross-sectional direction of the air path communication groove r2. Compared with the circular hole point jet, the gas flow sprayed from the elongated aperture can act on the soil in a larger transverse width in the air path communication groove r2, improving the range of the dredging hole h3 jet flow to dredge the possible local blocked soil in the air path communication groove r2, and effectively ensuring the unobstructedness of the air path communication groove r2.

[0087] In the present embodiment, at least one gas guide groove e is formed on the groove wall of the gas path communication groove r2, and one end of the gas guide groove e is in communication with the outer orifice of the dredging hole h3. The gas guide groove e provides an additional and extended flow path for the gas sprayed from the dredging hole h3. In addition, even if the outer orifice of the dredging hole h3 is partially blocked by a small amount of soil during the actual pile driving process, the high-pressure gas can still flow out through the gas guide groove e connected thereto. The gas entering the gas guide groove e will continue to flow along the path of the gas guide groove e and be sprayed into the larger space of the gas path communication groove r2, thereby still being able to dredge even if the orifice is partially blocked.

[0088] In the present embodiment, the upper and lower sides of the outer orifice of the dredging hole h3 are respectively connected to at least one gas guide groove e, and the connected gas guide grooves e extend vertically. This way of arranging the vertical gas guide grooves e on the upper and lower sides allows the gas flowing out of the dredging hole h3 to diffuse and flow in both upward and downward directions along the vertical gas guide grooves e, thereby expanding the range of action of the dredging gas flow in the length direction (vertical direction) of the pile body 1 in the gas path communication groove r2 and disturbing and dredging the possible blockage points in a larger longitudinal range.

[0089] In the present embodiment, the left and right end edges of the outer orifice of the dredging hole h3 are respectively the same distance from the corresponding two groove edges of the gas path communication groove r2. This symmetrical arrangement ensures that the high-speed gas flow sprayed from the elongated orifice can uniformly diffuse to the left and right spaces of the gas path communication groove r2.

[0090] In the present embodiment, the cross-sectional shape of the dredging hole h3 gradually and smoothly changes from the inner orifice (usually circular) on the hole wall of the central hole h1 to the outer orifice (transversely elongated) on the groove wall of the gas path communication groove r2. The gradually changing hole shape reduces the vortex generated by the sudden change in cross-sectional shape when the gas flows through the dredging hole h3, thereby reducing the local resistance loss of the gas flow and increasing the flow speed and smoothness of the gas in the dredging hole h3.

[0091] In the present embodiment, the cross-sectional area of the dredging hole h3 gradually decreases from the inner orifice on the hole wall of the central hole h1 to the outer orifice on the groove wall of the gas path communication groove r2, so that the gas is accelerated in the dredging hole h3, thereby being able to more effectively dredge the soil that may accumulate in the gas path communication groove r2 and improve the dredging efficiency and effect of the dredging hole h3.

[0092] In the present embodiment, the dredging hole h3 is polished and has a smooth hole wall, which functions similarly to the pressure relief hole h2 and will not be described again here.

[0093] It should be noted that the above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; even though the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A precast pile capable of preventing pile explosion during pile driving, characterized in that, The pile body (1) includes a central hole (h1) located in the pile body (1), and the top end of the central hole (h1) is located in the pile body (1) and the bottom end forms an opening at the bottom of the pile body (1); The pile body (1) is formed by large sections (11) with relatively large cross sections and small sections (12) with relatively small cross sections along the length direction of the pile body (1), and each outer peripheral wall of the pile body (1) is formed with a convex portion (c) protruding outward at a portion corresponding to the large section (11), so that each outer peripheral wall of the small section (12) and the surrounding soil form an air layer (r1) with gradually reduced thickness under the effect of the soil rebound characteristics when the pile is driven; The pile body (1) has at least one pressure relief hole (h2) connected from the hole wall of the central hole (h1) to the outer peripheral wall of the small section (12), for the soil to be pressed into the central hole (h1) when the pile is driven and for the high-pressure gas formed in the central hole (h1) to be discharged to the air layer (r1) outside the pile body (1). The pile body (1) is formed with an air passage communication groove (r2) extending along the length direction of the pile body (1) between any two adjacent convex portions (c) of the large section (11), and the side walls corresponding to the adjacent two convex portions (c) form at least part of the groove wall of the air passage communication groove (r2), and the space of the air passage communication groove (r2) is adapted to not be completely filled with soil when the pile is driven, so that the air layers (r1) corresponding to each small section (12) are connected in the pressure relief air passage.

2. A preform pile according to claim 1, characterised in that, The small section (12) of the pile body (1) near the top end of the central hole (h1) is provided with the pressure relief hole (h2).

3. A preform pile according to claim 1, characterised in that, The circumferential position of the outer hole of the pressure relief hole (h2) on the outer peripheral wall of the small section (12) is close to the air passage communication groove (r2).

4. A preform pile according to claim 1, characterised in that, The pressure relief hole (h2) includes a necked section (h21) and a retaining section (h22) connected in sequence, the necked section (h21) has a gradually reduced diameter in the pressure relief direction, and the inner hole of the pressure relief hole (h2) on the hole wall of the central hole (h1) is formed on the necked section, and the diameter of the retaining section (h22) remains unchanged in the pressure relief direction.

5. A preform pile according to claim 4, characterised in that, The pressure relief hole (h2) further includes an expanded section (h23) connected to the retaining section (h22), the diameter of the expanded section (h23) gradually increases in the pressure relief direction, and the outer hole of the pressure relief hole (h2) on the outer peripheral wall of the small section (12) is formed on the expanded section (h23).

6. A preform pile according to claim 1, characterised in that, The pressure relief hole (h2) is inclined upward from the inner hole on the hole wall of the central hole (h1) to the outer hole on the outer peripheral wall of the small section (12).

7. A preform pile according to claim 1, characterised in that, The hole wall of the pressure relief hole (h2) is a smooth hole wall after polishing treatment.

8. A preform pile according to claim 1, characterised in that, The pile body (1) has at least one dredging hole (h3) connected from the hole wall of the central hole (h1) to the groove wall of the air passage communication groove (r2), so that the high-pressure gas in the central hole (h1) is discharged when the pile is driven, to dredge the air passage of the air passage communication groove (r2).

9. A preform pile according to claim 8, characterised in that, The large section of the pile body (1) near the top end of the central hole (h1) is arranged with the dredging hole (h3).

10. A preform pile according to claim 8, characterised in that, The dredging hole (h3) is located on the outer orifice of the air path communication groove (r2), and the hole shape is an elongated shape extending horizontally.

11. A preform pile according to claim 10, characterised in that, At least one air guide groove (e) is formed on the groove wall of the air path communication groove (r2), and the air guide groove (e) is connected with the outer orifice of the dredging hole (h3), so as to expand the dredging range of the dredging hole (h3).

12. A preform pile according to claim 11, characterised in that, The upper and lower sides of the outer orifice are respectively connected with at least one air guide groove (e), and the air guide groove (e) extends vertically.

13. A preform pile according to claim 10, characterised in that, The left and right end edges of the outer orifice of the dredging hole (h3) are respectively away from the corresponding two groove edges of the air path communication groove (r2) by the same distance.

14. A preform pile according to claim 10, characterised in that, The cross-sectional shape of the dredging hole (h3) gradually changes from the inner orifice hole shape on the hole wall of the central hole (h1) to the outer orifice hole shape on the groove wall of the air path communication groove (r2).

15. A preform pile according to claim 8, characterised in that, The cross-sectional area of the dredging hole (h3) gradually decreases from the inner orifice on the hole wall of the central hole (h1) to the outer orifice on the groove wall of the air path communication groove (r2).

16. A preform pile according to claim 8, characterised in that The hole wall of the dredging hole (h3) is a smooth hole wall after polishing treatment.

17. A preform pile according to claim 1, characterised in that The side walls corresponding to the adjacent two convex parts (c) form the complete groove wall of the air path communication groove (r2), and the two side walls are connected and the connection part is formed with a chamfer structure (m1).

18. A preform pile according to claim 1, characterised in that, The side walls corresponding to the adjacent two convex parts (c) form the complete groove wall of the air path communication groove (r2), and the two side walls are a continuous arc-shaped wall (g).

19. A preform pile according to any one of claims 1 to 18, wherein, The intersection of the outer peripheral wall and the left and right two side walls of the convex part (c) is formed with a chamfer structure (m2).

20. A preform pile according to any one of claims 1 to 18, wherein, The intersection of the outer peripheral wall and the upper and lower two side walls of the convex part (c) is formed with a chamfer structure (m3), and the intersection of the upper and lower two side walls of the convex part (c) and the outer peripheral wall of the corresponding small section (12) is formed with a chamfer structure (m3).

21. A preform pile according to any one of claims 1 to 18, wherein, The upper and lower two side walls of the convex part (c) are inclined to the horizontal plane, and are adapted to make the upper and lower two side walls of the convex part (c) and the outer peripheral wall of the corresponding convex part (c) and the outer wall of the small section (12) form an obtuse angle (n).

22. A preform pile according to any one of claims 1 to 18, characterised in that, The central hole (h1) divides the pile body (1) into a solid part and a hollow part, and a peripheral steel reinforcement cage is arranged in the pile body (1), and the coverage range of the peripheral steel reinforcement cage includes the solid part and the hollow part.

23. A preform pile according to claim 22, characterised in that, The peripheral steel reinforcement cage includes a plurality of peripheral prestressed steel bars (21) extending along the length direction of the pile body (1) and distributed in the circumferential direction, and a peripheral stirrup (22) clamping and binding the plurality of peripheral prestressed steel bars (21) together, and the connection points of the peripheral stirrup (22) corresponding to each peripheral prestressed steel bar (21) are distributed along the peripheral prestressed steel bar (21) at intervals.

24. A preform pile according to claim 23, characterised in that, The peripheral prestressed steel bar (21) is arranged at equal intervals along the section edge of the small section (12).

25. A preform pile according to claim 24, characterised in that, The boundary defined by the sectional edges of the small segments (12) is provided with the peripheral prestressed steel bars (21) at the corners.

26. A preform pile according to claim 22, characterised in that The pile body (1) is further provided with an inner steel cage, which is located in the inner periphery of the peripheral steel cage and covers the solid part.

27. A preform pile according to claim 26, characterised in that The inner steel cage comprises a plurality of inner peripheral prestressed steel bars (31) extending along the length direction of the pile body (1) and distributed in the circumferential direction, and an inner peripheral stirrup (32) that is wrapped around and binds together the plurality of inner peripheral prestressed steel bars (31), the inner peripheral stirrup (32) being spaced apart along the inner peripheral prestressed steel bars (31) at the connecting points corresponding to each of the peripheral prestressed steel bars (21).

28. A preform pile according to claim 27, characterised in that, The plurality of inner peripheral prestressed steel bars (31) are arranged around the center of the cross section of the pile body (1) at equal intervals.

29. A preform pile according to claim 28, characterised in that, The inner peripheral stirrup (32) is in the form of a ring and is wrapped around the plurality of inner peripheral prestressed steel bars (31).

30. A preform pile according to any one of claims 1 to 18, wherein, The central hole (h1) and the central axis of the pile body (1) are coaxially arranged.

31. A preform pile according to any one of claims 1 to 18, wherein, The pile body (1) is in the form of a rectangular body structure, and the central hole (h1) is in the form of a cylindrical hole.

32. A preform pile according to any one of claims 1 to 18, characterised in that, The central hole (h1) divides the pile body (1) into a solid part and a hollow part, and the length of the solid part accounts for 3 / 100~1 / 2 of the length of the pile body (1).

33. A preform pile according to any one of claims 1 to 18, wherein, The pile body (1) comprises a plurality of unit piles, and the plurality of unit piles are sequentially connected at the ends to form the pile body (1).

Images