Weak intercalated layer external expansion type high-pressure jet grouting anti-floating pile construction method

Abstract

The invention discloses a weak intercalated layer external expansion type high-pressure jet grouting anti-floating pile construction method, relates to the field of foundations, and aims at improving the maximum upward pulling force capable of being borne by an anti-floating anchor rod and improving the pile forming quality of an anti-floating pile. According to the technical scheme, the weak intercalated layer external expansion type high-pressure jet grouting anti-floating pile construction method comprises the steps that the position of a pile hole is determined, the pile hole is constructed and formed, then high-pressure jet grouting operation is conducted in the pile hole, a pile head assembly and a pile casing are inserted into the pile hole, the pile head assembly is taken out from the interior of the pile casing, an anti-floating assembly is hoisted into the pile casing, and the pile head assembly and the pile casing are assembled. An overturning embedding assembly is fixed to the periphery of the anti-floating reinforcing steel bar, then aggregate is filled into the pile casing, the pile casing is pulled out, a movable reinforcing steel bar of the overturning embedding assembly is controlled to be overturned, unfolded and inserted into the soft stratum outside the pile hole, and finally grout is poured into the pile hole for maintenance. And the movable steel bars are overturned, unfolded and embedded into a jet grouting consolidation body corresponding to the soft stratum, so that the pile diameter and the bearing capacity of the anti-floating pile are improved. The construction method is used for construction of the anti-floating pile.

Description

Technical Field

[0001] The invention relates to the field of foundations, and in particular to an anti-floating anchor rod construction device with a recoverable pile head, and a high-pressure rotary jet anti-floating pile expanding outside a weak interlayer and a construction method thereof. Background Art

[0002] Anti-floating anchor rods are mainly used to solve the problem of buildings floating up under high water levels. The anti-floating anchor rods extend the anchor section deep into the stable strata underground, and use the friction between the anchor section and the surrounding strata to resist the buoyancy of the building caused by the action of groundwater, thereby maintaining the stability of the building. The friction between the anchor section of the anti-floating anchor rod and the stratum is closely related to the roughness, length, diameter of the anchor section, and the physical properties of the stratum soil.

[0003] The patent with the authorization announcement number CN 208685601 U discloses a composite expanded diameter anti-floating steel anchor rod, including a cement soil layer and a columnar anchor rod, the outer wall of the anchor rod is fixed with a plurality of connecting ribs extending outward, the connecting ribs are arranged along the axis direction of the anchor rod, the cement soil layer includes a column and a reducer, the diameter of the reducer is larger than the diameter of the column, and the reducer is integrally connected with the column along the axis direction of the column. On the one hand, the patent uses the variable diameter construction of the cement soil layer, and the weight of the soil layer is pressed on the reducer, which fully utilizes the strength of the anchor rod and the soil layer, thereby improving the pull-out resistance of the composite expanded diameter anti-floating steel anchor rod; on the other hand, the patent arranges a plurality of connecting ribs on the anchor rod, and the connecting ribs extend from the surface of the anchor rod and are embedded in the cement soil layer, thereby increasing the connection strength between the anchor rod and the cement soil layer, improving the integrity of the two, and thus improving the anti-floating effect.

[0004] For the above patent, the connecting rib is fixedly arranged on the outer wall of the anchor rod, and the end of the connecting rib away from the anchor rod cannot exceed the range of the pile hole, that is, the connecting rib cannot be embedded in the reducer, otherwise the anchor rod cannot be inserted into the pile hole. Since the connecting rib is short, it cannot effectively increase the connection strength between the anchor rod and the cement soil layer. The connecting rib will also affect the insertion construction of the anchor rod, causing the anchor rod to bend and fail to be inserted to the predetermined position. In addition, the column and the reducer are both constructed with a high-pressure rotary jet pile driver. The strength of the column and the reducer themselves is not high, and it is difficult to effectively improve the tolerable pull-out resistance of the anchor rod.

[0005] Soft sand layers under high water level conditions often become a problem in engineering construction due to their loose structure and weak bearing capacity. The instability of this type of soil layer directly affects the bearing capacity of the foundation and the safety of the structure. Especially in an environment with a high groundwater level, the soil layer not only has insufficient bearing capacity, but may also be affected by the buoyancy of groundwater, causing the floating of buildings or structures, thereby causing safety problems. At present, high-pressure rotary grouting and anti-floating anchor rods are commonly used to treat soft sand layers under high water level conditions. High-pressure rotary grouting technology mixes high-pressure spray slurry with the soil layer to form a reinforced pile body, thereby improving the bearing capacity and stability of the foundation. Anti-floating anchor rod technology sets anchor rods in the soil layer and uses bonding materials to firmly combine the anchor rods with the soil layer to resist the buoyancy of groundwater. At present, high-pressure rotary grouting and anti-floating anchor rod technology are usually used separately at the construction site. High-pressure rotary grouting needs to be carried out first, and then the anti-floating anchor rods are installed after the soil layer is reinforced. The two steps of construction need to be carried out alternately. This process often requires a long waiting time and requires more equipment and manpower. Summary of the invention

[0006] The present invention firstly provides an anti-floating anchor rod construction device with a recyclable pile head, the purpose of which is to increase the pull-out resistance that the anti-floating anchor rod can withstand and improve the pile quality of the anti-floating pile.

[0007] The technical scheme adopted by the present invention is: an anti-floating anchor construction device with a recyclable pile head, comprising a pile head assembly, a casing and an anti-floating assembly, the pile head assembly comprising a pile head and an operating rod, the lower section of the pile head is conical, the upper section is cylindrical, and the bottom surface of the cone is equal to and coincides with the bottom surface diameter of the cylinder, the upper section of the pile head is provided with an external thread, the center of the top surface of the upper section of the pile head is fixedly connected to the operating rod, and the center line of the operating rod coincides with the center line of the pile head; the casing is a cylinder, the lower end of the casing is provided with an internal thread adapted to the external thread of the pile head, and the inner diameter of the casing is not less than the diameter of the upper section of the pile head; the anti-floating assembly comprises anti-floating steel bars, a positioning ring and a flip embedding assembly, at least one anti-floating steel bar, each anti-floating steel bar is fixed to the positioning ring, the positioning ring comprises an outer ring, at least two positioning rings are arranged at intervals, the outer ring of the positioning ring is aligned with the anti-floating steel bar The diameter of the projection on the vertical cross section is adapted to the inner diameter of the casing; at least one flip embedding component is also fixed to the outer periphery of the anti-floating steel bar, the flip embedding component includes a fixed steel bar and a movable steel bar, one end of the fixed steel bar is fixedly connected to the anti-floating steel bar, and the fixed steel bar and the anti-floating steel bar are perpendicular to each other, the other end of the fixed steel bar is rotatably connected to the movable steel bar, the movable steel bar can be rotated until the movable steel bar is completely located within the cylindrical range corresponding to the outer ring of each positioning ring, and can also be rotated until the movable steel bar is partially located outside the cylindrical range corresponding to the outer ring of each positioning ring, the fixed steel bar and the anti-floating steel bars at both ends and the movable steel bar are located in the same plane, the center line of the anti-floating steel bar is set vertically, and the end of the anti-floating steel bar inserted into the bottom of the pile hole is facing downward, and the rotation range of the movable steel bar around the fixed steel bar is located above the horizontal plane corresponding to the fixed steel bar.

[0008] In order to ensure the strength of the pile head assembly, further: the pile head is made of metal, or the pile head includes a metal shell and reinforced concrete inside the metal shell.

[0009] The positioning ring plays the role of fixing each anti-floating steel bar as a whole. After the anti-floating assembly is placed in the casing, the positioning ring plays the role of keeping the anti-floating steel bar arranged along the center line of the casing. Specifically: the positioning ring is provided with an outer ring, a middle ring and an inner ring in a plane perpendicular to the anti-floating steel bar. The outer ring, the middle ring and the inner ring are all circular and their centers coincide. The outer diameter of the outer ring is not greater than the inner diameter of the casing. The outer ring and the middle ring are connected by at least one connecting rod, and the middle ring and the inner ring are connected by at least one connecting rod. Each anti-floating steel bar is fixed between the middle ring and the inner ring.

[0010] After the movable steel bars of the flip embedding assembly are flipped outward and downward in the pile hole and unfolded, they can be inserted into the stratum outside the pile hole, and then embedded in the rotary grouting consolidation body outside the pile hole. Specifically: a first connecting seat is provided at one end of the fixed steel bar away from the anti-floating steel bar, and the first connecting seat is provided with an axial hole that is perpendicular to both the fixed steel bar and the anti-floating steel bar. A second connecting seat is provided at one end of the movable steel bar, and the second connecting seat is provided with a rotating shaft, which is passed through the axial hole. The first connecting seat or the second connecting seat is also provided with a limit baffle that limits the maximum angle and the minimum angle formed by the fixed steel bar and the movable steel bar. The axial hole of the first connecting seat is preferably eccentrically arranged, and the second connecting seat is eccentrically connected to the first connecting seat. When the lower end of the casing corresponds to the position of the flip embedding assembly, the upper end of the casing is pressed down or hammered, and the movable steel bar of the flip embedding assembly is naturally flipped and unfolded and maintained in the unfolded state.

[0011] In order to facilitate the flipping of the movable steel bars of the embedded component to flip outward and downward under the action of external force and insert them into the stratum outside the pile hole, further: the maximum angle formed by the fixed steel bars and the movable steel bars is a straight angle, and the minimum angle formed by the fixed steel bars and the movable steel bars is a right angle or an obtuse angle.

[0012] In order to make the movable steel bar of the flip embedded component automatically unfold without the restriction of the casing, further: an elastic member is provided between the fixed steel bar and the movable steel bar of the flip embedded component to make the movable steel bar automatically unfold. Specifically: the elastic member can be a tension spring, a spring, a torsion spring or an elastic sheet.

[0013] A fixed embedded component that is always located within the range of the pile hole can also be fixedly arranged on the outside of the anti-floating steel bar. The fixed embedded component is finally embedded in the cast consolidation body and will not enter the rotary spray consolidation body. Furthermore: the outside of the anti-floating steel bar also has at least one fixed embedded component, and the fixed embedded component is located within the cylindrical range corresponding to the outer ring of each positioning ring. In order to facilitate the installation of the fixed embedded component and ensure the stability of the fixed embedded component, specifically: the fixed embedded component includes a fixed tube and at least one steel bar segment fixed to the outer wall of the fixed tube, the anti-floating steel bar is passed through the fixed tube and fixed by welding, the steel bar segment is perpendicular to the anti-floating steel bar, or the end of the steel bar segment away from the anti-floating steel bar is tilted upward and forms an acute angle with the anti-floating steel bar.

[0014] The present invention also provides a soft interlayer outward expansion type high-pressure rotary jet anti-floating pile, the purpose of which is also to increase the pull-out resistance that the anti-floating steel bar can bear and improve the pile quality of the anti-floating pile. The soft interlayer outward expansion type high-pressure rotary jet anti-floating pile has a vertically arranged pile hole and penetrates the upper hard stratum into the lower soft stratum. The inside of the pile hole is a cast consolidation body, and the outside of the pile hole is a rotary jet consolidation body. The cast consolidation body is a consolidation body formed by placing the anti-floating component in any of the above-mentioned "anti-floating anchor construction devices with recoverable pile heads" into the pile hole, filling aggregates and pouring slurry. The rotary jet consolidation body is a consolidation body formed by high-pressure rotary jet slurry on the wall of the pile hole. The cast consolidation body and the rotary jet consolidation body are a whole, and the movable steel bars of the flip embedded component are unfolded and embedded in the rotary jet consolidation body corresponding to the soft stratum.

[0015] In order to improve the anti-floating property of the anti-floating steel bar, further: at least one fixed embedded component is inherently disposed on the outer side of the anti-floating steel bar, and the fixed embedded component is embedded in a cast consolidation body corresponding to the hard stratum.

[0016] In order to improve the anti-floating property of the anti-floating steel bar, further: the pile hole also penetrates the soft stratum and reaches or enters the good stratum below the soft stratum, the soft stratum is a sand layer, and the good stratum is a pebble layer or a bedrock layer.

[0017] The beneficial effects of the anti-floating anchor construction device with a recyclable pile head and the weak interlayer outward expansion type high-pressure rotary grouting anti-floating pile of the present invention are: after the pile head and the casing are threadedly connected, the pile head assembly and the casing can be inserted down to a predetermined depth by pressing down or hammering the upper end of the casing, and ensure that they are inserted down to a predetermined position in the pile hole. By turning the operating rod, the pile head rotates synchronously, the pile head and the casing are disengaged, and the pile head can be taken out of the casing to achieve the recycling of the pile head assembly, and the recycled pile head assembly can be reused. When the casing is located in the pile hole, the anti-floating assembly is hoisted into the casing, and the positioning ring can play a role in keeping the anti-floating steel bars arranged along the center line of the casing, so that the anti-floating steel bars are located near the center line of the pile hole. When the anti-floating assembly is hoisted into the casing, the movable steel bars are rotated until the movable steel bars are completely located within the cylindrical range corresponding to the outer rings of each positioning ring, and the flipping of the embedded assembly does not affect the construction of the anti-floating assembly hoisted into the casing at all. After the casing is pulled out of the pile hole, it can also be recycled and reused, and the movable steel bars of the flip embedding assembly are flipped and unfolded and inserted into the stratum outside the pile hole range, and finally embedded in the rotary jet consolidation body outside the pile hole range, and the fixed steel bars of the flip embedding assembly are finally embedded in the cast consolidation body. The cast consolidation body and the rotary jet consolidation body are solidified into a whole, which significantly improves the pile diameter and bearing capacity of the anti-floating pile and improves the pull-out resistance that the anti-floating steel bar can withstand. The present invention improves the pile quality of the anti-floating pile and improves the pull-out resistance that the anti-floating steel bar can withstand.

[0018] The present invention also provides a construction method for high-pressure rotary grouting anti-floating piles with a weak interlayer expanding outward. The construction method is both the use method of the first subject "anti-floating anchor construction device with recoverable pile head" and the construction method of the second subject "high-pressure rotary grouting anti-floating piles with a weak interlayer expanding outward". The purpose is also to enhance the pull-out resistance that the anti-floating anchor can withstand and to improve the quality of the anti-floating piles.

[0019] The construction method of the soft interlayer outward expansion type high-pressure rotary grouting anti-floating piles is to construct the anti-floating piles in the high water level stratum with hard stratum on the upper part and soft stratum on the lower part, including the following steps:

[0020] S1. Determine the location of the pile hole and construct the pile hole. The pile hole penetrates the hard stratum from top to bottom and enters the soft stratum. The hard stratum is generally a pebble layer, and the soft stratum is generally a sand layer or other stratum that can be treated by high-pressure jet grouting. In order to improve the anti-floating property of the anti-floating steel bar, it is best for the pile hole to penetrate the soft stratum and reach or enter the good stratum below the soft stratum, which is a pebble layer or bedrock layer.

[0021] S2. Carry out high-pressure rotary grouting operations from bottom to top in the pile hole.

[0022] S3. Assemble the pile head assembly and casing in any of the above-mentioned "anti-floating anchor construction devices with recyclable pile heads" so that the pile head is threadedly connected to the lower end of the casing. Before the high-pressure rotary spraying slurry solidifies, the pile head assembly and casing are inserted into the pile hole by pressing down or hammering the upper end of the casing.

[0023] S4. Turn the operating lever to disengage the pile head from the casing, and remove the pile head assembly from the casing.

[0024] S5. Temporarily fix the grouting pipe in the anti-floating component of any of the above-mentioned "anti-floating anchor construction devices with recoverable pile heads", then hoist the anti-floating component into the casing, and the section of the anti-floating steel bars located in the soft stratum is provided with a flip embedding component.

[0025] In order to further improve the quality of anti-floating piles, further steps are as follows: flip embedded components are arranged at intervals in the sections where the anti-floating steel bars are located in the pile hole; or, at least one flip embedded component is provided in the sections where the anti-floating steel bars are located in the soft strata, and at least one fixed embedded component is fixed to the sections where the anti-floating steel bars are located in other strata, and the fixed embedded components are located in the cylindrical range corresponding to the outer ring of each positioning ring.

[0026] In order to ensure that the anti-floating steel bars are always arranged along the center line of the casing during construction, and to facilitate the installation of the grouting pipe, further: the positioning ring is provided with an outer ring, a middle ring and an inner ring in a plane perpendicular to the anti-floating steel bars, the outer ring, the middle ring and the inner ring are all circular and the centers of the circles coincide, the outer diameter of the outer ring is not greater than the inner diameter of the casing, the outer ring and the middle ring are connected by at least one connecting rod, the middle ring and the inner ring are connected by at least one connecting rod, each anti-floating steel bar is fixed between the middle ring and the inner ring, the grouting pipe is arranged along the anti-floating steel bars and clamped in the inner ring of each fixing ring, and the slurry outlet end of the grouting pipe is located at the lower end of the anti-floating steel bars.

[0027] S6. Fill aggregate into the casing and lift it up, using a method of filling aggregate in layers and gradually lifting the casing up until the casing is pulled out of the pile hole and the pile hole is filled with aggregate, and the movable steel bars of the flip embedding assembly are controlled to flip and unfold and insert into the soft stratum outside the pile hole.

[0028] Several methods are provided below to control the active steel bars of the flip embedded assembly to flip, unfold, and insert into the soft stratum outside the pile hole. Specifically: in step S5, when the lower end of the casing corresponds to the position of the flip embedded assembly, the active steel bars of the flip embedded assembly are flipped, unfolded, and inserted into the soft stratum outside the pile hole by pressing down or hammering the upper end of the casing; or, when the lower end of the casing exceeds the highest flip embedded assembly, the active steel bars of each flip embedded assembly are flipped, unfolded, and inserted into the soft stratum outside the pile hole by lifting the anti-floating steel bars; or an elastic member that allows the active steel bars to automatically unfold can be provided between the fixed steel bars and the active steel bars of the flip embedded assembly, and the active steel bars are automatically unfolded during the lifting of the casing.

[0029] In order to improve the compactness of the aggregate and promote the diffusion of the aggregate to the soft stratum outside the pile hole, further: the aggregate in step S5 is pebbles with a diameter of 0.5 to 2.0 cm, and after the pebbles are filled in layers, vibration is also performed.

[0030] S7. Grout is poured into the pile hole through a grouting pipe and maintained, so that a poured consolidation body is formed inside the pile hole and a rotary jet consolidation body is formed outside the pile hole. The poured consolidation body and the rotary jet consolidation body solidify into a whole.

[0031] The beneficial effects of the weak interlayer outward expansion type high-pressure rotary grouting anti-floating pile construction method of the present invention are: after the high-pressure rotary grouting operation, the anti-floating anchor rod construction is immediately carried out. By combining the high-pressure rotary grouting technology with the anti-floating anchor rod technology, the waste of equipment and manpower caused by the repeated hole-guiding construction of the anti-floating anchor rod in the later stage is avoided, and the construction period is also saved. The pile head assembly and the casing in the "anti-floating anchor rod construction device with recyclable pile head" are assembled and inserted into the pile hole. By pressing down or hammering the upper end of the casing, the pile head assembly and the casing can be inserted to a predetermined depth, and it is ensured that the pile head is inserted into a predetermined position in the pile hole, and the pile head assembly and the casing can be recycled and reused. The movable steel bars of the flip embedded assembly can be rotated until the movable steel bars are completely located within the cylindrical range corresponding to the outer rings of each positioning ring. When the anti-floating assembly is hoisted into the casing, the movable steel bars are in the unexpanded state. The flip embedded assembly does not affect the hoisting construction of the anti-floating assembly, and it can be ensured that the anti-floating steel bars are inserted to the bottom of the pile hole. When filling the casing with aggregate, the aggregate will not only fill the pile hole, but also spread to the weak strata, making the strength of the jet-sprayed consolidation body corresponding to the weak strata higher. Whether filling the aggregate in layers and gradually lifting the casing, or vibrating the aggregate, the filled aggregate will be squeezed to increase the density of the aggregate in the pile hole and promote the diffusion of the aggregate to the weak strata. When the movable steel bars of the flip embedded component are flipped and unfolded by pressing down or hammering the upper end of the casing, the lower end of the casing will also squeeze the filled aggregate, increase the density of the aggregate in the pile hole, and promote the diffusion of the aggregate to the weak strata. After the casing is taken out of the pile hole, the movable steel bars of the flip embedded component automatically or under the action of external force flip outward and downward to unfold, and the movable steel bars are inserted into the soft strata outside the pile hole, and finally embedded in the jet-sprayed consolidation body corresponding to the soft stratum, realizing the expansion of the anti-floating pile in the weak interlayer. The cast-in-place consolidation body and the rotary jet consolidation body solidify into a whole, which effectively increases the pile diameter and strength of the anti-floating pile in the soft stratum. The present invention improves the pile quality of the anti-floating pile and enhances the tolerable pull-out resistance of the anti-floating steel bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of an embodiment of an anti-floating component in an anti-floating anchor rod construction device with a recoverable pile head according to the present invention.

[0033] Figure 2 yes Figure 1 A schematic structural diagram of the anti-floating component shown in FIG. 1 is a schematic structural diagram of the anti-floating component on the cross section corresponding to the positioning ring.

[0034] Figure 3 yes Figure 1 The schematic diagram of the flip embedding component before unfolding in the illustrated embodiment.

[0035] Figure 4 yes Figure 1 A schematic diagram of the embodiment shown is a diagram of the flipped embedded component after it is unfolded.

[0036] Figure 5 yes Figure 1 A schematic diagram of an example of a fixed embedding component in the illustrated embodiment.

[0037] Figure 6 It is a schematic diagram after the pile head assembly and casing are inserted into the pile hole.

[0038] Figure 7 It is a schematic diagram after the anti-floating assembly is hoisted into the casing.

[0039] Figure 8 It is a structural schematic diagram of the soft interlayer outward-expanding high-pressure rotary grouting anti-floating pile of the present invention.

[0040] Figure numerals: pile head assembly 1, pile head 1-1, operating rod 1-2, casing 2, anti-floating steel bar 3, flip embedded assembly 4, fixed steel bar 4-1, movable steel bar 4-2, first connecting seat 4-3, second connecting seat 4-4, limit baffle 4-5, grouting pipe 5, fixed embedded assembly 6, fixed tube 6-1, steel bar segment 6-2, positioning ring 7, outer ring 7-1, middle ring 7-2, inner ring 7-3, connecting rod 7-4, hard stratum 8-1, soft stratum 8-2, good stratum 8-3, pile hole 9, rotary jet consolidation body 9-2, cast consolidation body 9-1. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings.

[0042] The first subject of the present invention is a pile head recyclable anti-floating anchor rod construction device, which is used to construct an anti-floating anchor rod in a pile hole 9. Figure 1 and Figure 6 to Figure 8 The anti-floating anchor construction device with a recyclable pile head includes a pile head assembly 1, a casing 2 and an anti-floating assembly. The pile head assembly 1 includes a pile head 1-1 and an operating rod 1-2. The lower section of the pile head 1-1 is conical and the upper section is cylindrical, and the bottom surface of the cone and the bottom surface of the cylinder have the same diameter and overlap. The upper section of the pile head 1-1 is provided with an external thread, and the center of the top surface of the upper section of the pile head 1-1 is fixedly connected to the operating rod 1-2. A connecting hole can be provided at the top of the pile head 1-1, and the lower end of the operating rod 1-2 is fixedly connected to the connecting hole of the pile head 1-1. The operating rod 1-2 is used to rotate the pile head 1-1, so the center line of the operating rod 1-2 coincides with the center line of the pile head 1-1. The operating rod 1-2 is generally a steel pipe and is welded and fixed to the pile head 1-1. In order to ensure the strength of the pile head assembly 1, the pile head 1-1 is made of metal, generally steel; or, the pile head 1-1 includes a metal shell and reinforced concrete inside the metal shell, and the reinforcement of the reinforced concrete can be arranged along the radial direction of the pile head 1-1 and fixedly connected to the metal shell. The metal shell plays the role of a casting template and also improves the flatness of the surface of the pile head 1-1.

[0043] The casing 2 is a cylinder, generally a steel cylinder, and the lower end of the casing 2 is provided with an internal thread adapted to the external thread of the pile head 1-1, and the inner diameter of the casing 2 is not less than the diameter of the upper section of the pile head 1-1. The pile head 1-1 is threadedly connected to the lower end of the casing 2, and the operating rod 1-2 is located in the casing 2. By rotating the operating rod 1-2, the casing 2 can be disengaged from the pile head 1-1, and the pile head 1-1 can be taken out from the upper end of the casing 2.

[0044] The anti-floating assembly includes an anti-floating steel bar 3, a positioning ring 7 and a flip embedding assembly 4. There is at least one anti-floating steel bar 3, and generally a plurality of anti-floating steel bars 3, forming an anti-floating steel bar bundle. In order to fix each anti-floating steel bar 3 as a whole, each anti-floating steel bar 3 is fixed to the positioning ring 7, and there are at least two positioning rings 7 and arranged at intervals, for example, each anti-floating steel bar 3 is clamped in the positioning ring 7, or each anti-floating steel bar 3 is welded to the positioning ring 7. In order to ensure that the anti-floating steel bars 3 are always arranged along the center line of the casing 2 during construction, the positioning ring 7 includes an outer ring 7-1, and the diameter of the projection of the outer ring 7-1 on the section perpendicular to the anti-floating steel bar 3 is adapted to the inner diameter of the casing 2. For example, see Figure 2 The positioning ring 7 is provided with an outer ring 7-1, a middle ring 7-2 and an inner ring 7-3 in a plane perpendicular to the anti-floating steel bar 3. The outer ring 7-1, the middle ring 7-2 and the inner ring 7-3 are all in annular shape and their centers coincide. The outer ring 7-1 and the middle ring 7-2 are connected by at least one connecting rod 7-4, and the middle ring 7-2 and the inner ring 7-3 are connected by at least one connecting rod 7-4. The connecting rod 7-4 makes the outer ring 7-1, the middle ring 7-2 and the inner ring 7-3 a whole. The outer diameter of the outer ring 7-1 is not greater than the inner diameter of the casing 2. The outer ring 7-1 is matched with the inner wall clearance of the casing 2 to ensure that the anti-floating assembly can be smoothly hoisted into the casing 2. Each anti-floating steel bar 3 is fixed between the middle ring 7-2 and the inner ring 7-3. The spacing between the middle ring 7-2 and the inner ring 7-3 is preferably consistent with the diameter of the anti-floating steel bar 3, so as to fix the position of the anti-floating steel bar 3. The inner hole of the inner ring 7 - 3 can be used to arrange the grouting pipe 5 .

[0045] At least one flip embedding component 4 is also fixed to the outer periphery of the anti-floating steel bar 3. The flip embedding component 4 has two states: flipped and unfolded and not flipped and unfolded. When the anti-floating component is located in the casing 2, the flip embedding component 4 is in the not flipped and unfolded state. Figure 1 , Figure 3 and Figure 7 After the casing 2 is moved out of the pile hole 9, the flip embedding assembly 4 can be in a flipped and unfolded state, as shown in FIG. Figure 4 and Figure 8As shown. The flip embedding assembly 4 includes a fixed steel bar 4-1 and a movable steel bar 4-2. The fixed steel bar 4-1 is arranged along the radial direction of the casing 2, that is, the fixed steel bar 4-1 and the anti-floating steel bar 3 are perpendicular to each other, one end of the fixed steel bar 4-1 is fixedly connected to the anti-floating steel bar 3, for example, by welding, and the other end of the fixed steel bar 4-1 is rotatably connected to the movable steel bar 4-2. No matter how the movable steel bar 4-2 rotates around the fixed steel bar 4-1, the fixed steel bar 4-1 and the anti-floating steel bars 3 at both ends and the movable steel bar 4-2 are always located in the same plane. Set the center line of the anti-floating steel bar 3 vertically, and the end of the anti-floating steel bar 3 inserted into the bottom of the pile hole 9 is facing downward, then the rotation range of the movable steel bar 4-2 around the fixed steel bar 4-1 is located above the horizontal plane corresponding to the fixed steel bar 4-1, that is, the movable steel bar 4-2 cannot rotate to below the horizontal plane corresponding to the fixed steel bar 4-1. The movable steel bar 4-2 rotates around the fixed steel bar 4-1, and can be rotated until the movable steel bar 4-2 is completely located in the cylindrical range corresponding to the outer ring 7-1 of each positioning ring 7, at which time the fixed steel bar 4-1 and the movable steel bar 4-2 are completely located in the range corresponding to the casing 2; the movable steel bar 4-2 can also be rotated until the movable steel bar 4-2 is partially located outside the cylindrical range corresponding to the outer ring 7-1 of each positioning ring 7, at which time the fixed steel bar 4-1 is completely located in the range corresponding to the casing 2, and the movable steel bar 4-2 is partially located outside the range corresponding to the casing 2 and partially located outside the range corresponding to the casing 2. The total length of the mutually connected fixed steel bar 4-1 and the movable steel bar 4-2 is greater than the radius of the casing 2, so that the movable steel bar 4-2 can expand outward after being unfolded. The length of the fixed steel bar 4-1 is preferably consistent with the radius of the casing 2, and one end of the fixed steel bar 4-1 connected to the movable steel bar 4-2 abuts against the inner wall of the casing 2, and the movable steel bar 4-2 can be rotated to form a right angle with the fixed steel bar 4-1, so that the movable steel bar 4-2 can expand outward as much as possible. After the movable steel bar 4 - 2 of the flip embedding assembly 4 is flipped outward and downward and unfolded, it can be inserted into the soft stratum outside the pile hole 9 and finally embedded in the rotary jet consolidation body 9 - 2.

[0046] The following provides an embodiment in which the fixed steel bar 4-1 and the movable steel bar 4-2 are rotatably connected. Figure 3 and Figure 4The end of the fixed steel bar 4-1 away from the anti-floating steel bar 3 is provided with a first connection seat 4-3, and the first connection seat 4-3 is provided with an axial hole that is perpendicular to both the fixed steel bar 4-1 and the anti-floating steel bar 3. The end of the movable steel bar 4-2 is provided with a second connection seat 4-4, and the second connection seat 4-4 is provided with a rotating shaft, and the rotating shaft is passed through the axial hole. The first connection seat 4-3 or the second connection seat 4-4 is also provided with a limit baffle 4-5 that limits the fixed steel bar 4-1 and the movable steel bar 4-2 to form an extreme angle. The axial hole of the first connection seat 4-3 is preferably arranged eccentrically, and the second connection seat 4-4 is eccentrically connected to the first connection seat 4-3. When the lower end of the casing 2 corresponds to the position of the flip embedded component 4, the upper end of the casing 2 is pressed down or hammered, and the movable steel bar 4-2 of the flip embedded component 4 naturally flips and unfolds and maintains the unfolded state. The extreme angle formed by the fixed steel bar 4-1 and the movable steel bar 4-2 includes a maximum angle and a minimum angle. The movable steel bar 4-2 is unfolded after the casing 2 is taken out. In order to facilitate the movable steel bar 4-2 of the flip embedded component 4 to flip outward and downward under the action of external force, for example, in order to facilitate the use of the downward pressure of the casing 2 to unfold the movable steel bar 4-2, the minimum angle formed by the fixed steel bar 4-1 and the movable steel bar 4-2 is a right angle or an obtuse angle, and the movable steel bar 4-2 abuts against the casing 2 when it is in the casing 2. In order to improve the anti-floating property of the anti-floating steel bar 3, the maximum angle formed by the fixed steel bar 4-1 and the movable steel bar 4-2 is a flat angle, that is, the fixed steel bar 4-1 and the movable steel bar 4-2 are arranged along the radial direction of the anti-floating steel bar 3. In order to make the movable steel bar 4-2 of the flip embedded component 4 automatically unfolded after there is no restriction of the casing 2, or have a tendency to automatically unfold, an elastic member that enables the movable steel bar 4-2 to unfold automatically can also be arranged between the fixed steel bar 4-1 and the movable steel bar 4-2, and the elastic member can be a tension spring, a spring, a torsion spring, an elastic sheet, etc. The movable steel bar 4-2 automatically unfolds during the lifting of the casing 2.

[0047] In order to improve the anti-floating property of the anti-floating steel bar 3, a fixed embedding component 6 which is always located within the pile hole 9 can also be fixedly arranged outside the anti-floating steel bar 3. The fixed embedding component 6 is always located within the cylindrical range corresponding to the outer ring 7-1 of each positioning ring 7, and is finally embedded in the cast consolidation body 9-1 without entering the rotary spray consolidation body 9-2. Figure 1 At least one fixed embedded component 6 is also fixed to the outside of the anti-floating steel bar 3. The fixed embedded components 6 are generally multiple and arranged at intervals. The following provides an example of the fixed embedded component 6. Figure 5The fixed embedded component 6 includes a fixed tube 6-1 and at least one steel bar segment 6-2 fixed to the outer wall of the fixed tube 6-1. The anti-floating steel bar 3 is passed through the fixed tube 6-1 and welded and fixed. The steel bar segment 6-2 is welded and connected to the fixed tube 6-1. Different steel bar segments 6-2 avoid crossing and are placed at equal intervals according to a circular angle. The steel bar segment 6-2 is perpendicular to the anti-floating steel bar 3, or one end of the steel bar segment 6-2 away from the anti-floating steel bar 3 is tilted upward and forms an acute angle with the anti-floating steel bar 3.

[0048] The second subject of the present invention is a soft interlayer outward expansion type high pressure rotary grouting anti-floating pile, which is actually an anti-floating pile constructed by the first subject. Figure 8 The pile hole 9 of the soft interlayer outward expansion type high-pressure rotary jet anti-floating pile is arranged vertically and penetrates the upper hard stratum 8-1 to enter the lower soft stratum 8-2. The pile hole 9 can also penetrate the soft stratum 8-2 to reach or enter the good stratum 8-3 below the soft stratum 8-2. The hard stratum 8-1 is generally a pebble layer, the soft stratum 8-2 is generally a sand layer or other stratum that can be treated by high-pressure rotary jetting, and the good stratum 8-3 is generally a pebble layer or a bedrock layer. The inside of the pile hole 9 is a cast consolidation body 9-1, and the outside of the pile hole 9 is a rotary jet consolidation body 9-2. The cast consolidation body 9-1 is a consolidation body formed by placing the anti-floating components in any of the above-mentioned "anti-floating anchor construction devices with recoverable pile heads" into the pile hole 9, filling aggregates and pouring slurry. In order to facilitate the diffusion of aggregate and dense filling, the aggregate is preferably pebbles, for example, the aggregate is pebbles with a diameter of 0.5 to 2.0 cm, and a layered and step-by-step filling method is adopted during filling. The jet-jet consolidation body 9-2 is a consolidation body formed by jetting slurry at high pressure to the wall of the pile hole 9. The cast consolidation body 9-1 and the jet-jet consolidation body 9-2 are synchronously solidified and become a whole, and the movable steel bar 4-2 of the flip embedding component 4 is unfolded and embedded in the jet-jet consolidation body 9-2 corresponding to the soft stratum 8-2. In order to improve the anti-floating property of the anti-floating steel bar 3, when the outer side of the anti-floating steel bar 3 also has a fixed embedding component 6, there is at least one fixed embedding component 6, generally a plurality of fixed embedding components 6 and arranged at intervals, and the fixed embedding component 6 is embedded in the cast consolidation body 9-1 corresponding to the hard stratum 8-1.

[0049] The third subject of the present invention is a construction method for high-pressure rotary grouting anti-floating piles with outward expansion of weak interlayer. This construction method is both the use method of the above-mentioned first subject "anti-floating anchor construction device with recoverable pile head" and the construction method of the above-mentioned second subject "high-pressure rotary grouting anti-floating piles with outward expansion of weak interlayer".

[0050] See also Figure 6 to Figure 8 The method for constructing soft interlayer outward-expanding high-pressure rotary jet anti-floating piles comprises the following steps: constructing anti-floating piles in a high-water stratum with a hard stratum 8-1 at the top and a soft stratum 8-2 at the bottom.

[0051] S1. Determine the position of the pile hole 9 and construct the pile hole 9. The pile hole 9 penetrates the hard stratum 8-1 from top to bottom and enters the soft stratum 8-2. When determining the position of the pile hole 9, it is generally necessary to excavate to 50cm above the base elevation, and measure and determine the plane position of the pile hole 9. The hard stratum 8-1 is generally a pebble layer, and the soft stratum 8-2 is generally a sand layer or other stratum that can be treated by high-pressure rotary jetting. When constructing the pile hole 9, a down-the-hole drill is used to lead the hole. After the hole is formed, a PVC pipe with a diameter of 110mm is placed. The pre-buried length depends on the hole depth, and then the casing used for drilling the pipe in the hole is pulled out in order. It is best for the pile hole 9 to also pass through the soft stratum 8-2 to reach or enter the soft stratum 8-2 in the good stratum below. The good stratum 8-3 is generally a pebble layer or a bedrock layer.

[0052] S2. Perform high-pressure rotary grouting operation from bottom to top in the pile hole 9.

[0053] Insert the jet pipe into the pile hole 9. When the nozzle of the jet pipe reaches the designed elevation, the jet grouting can be performed. For example, the slurry uses ordinary Portland cement with a strength grade of P.0.42.5, and the water-cement ratio of the slurry is 0.8-1.0. After the jet grouting parameters reach the specified values, the jet pipe is immediately lifted according to the requirements of the high-pressure rotary jetting process, and the jet grouting is rotated from bottom to top to 500mm above the top surface of the soft stratum 8-2. The overlap length of the segmented lifting of the jet pipe is not less than 100mm. When there is no pressure back grouting in the lead hole section, the jet pipe is quickly pulled out. In order to prevent the slurry from solidifying and shrinking and affecting the elevation of the pile top, measures such as grouting backfilling or secondary grouting are also required at the original hole position.

[0054] S3. Assemble the pile head assembly 1 and casing 2 in any of the above-mentioned "anti-floating anchor construction devices with recyclable pile heads" so that the pile head 1-1 is threadedly connected to the lower end of the casing 2. Before the high-pressure rotary spraying slurry solidifies, the pile head assembly 1 and casing 2 are inserted into the pile hole 9 by pressing down or hammering the upper end of the casing 2.

[0055] The structure of the pile head assembly 1 and the casing 2 is described in the first topic above. After the pile head assembly 1 and the casing 2 are assembled, before the high-pressure rotary spray slurry solidifies, the pile head assembly 1 and the casing 2 are generally inserted into the pile hole 9 by a vibration hammer method. During the insertion process, the force and speed of the vibration hammer are strictly controlled to avoid slurry return from the treated soil layer, while ensuring that the verticality of the hole meets the design requirements.

[0056] S4, rotating the operating rod 1-2 to disengage the pile head 1-1 from the casing 2, and taking out the pile head assembly 1 from the inside of the casing 2. After the casing 2 is lowered to the predetermined position, the operating rod 1-2 is rotated by the clamp, the pile head 1-1 is disengaged from the casing 2, and the pile head assembly 1 is taken out from the inside of the casing 2, so that the pile head assembly 1 is recovered.

[0057] S5, temporarily fixing the grouting pipe 5 in the anti-floating assembly in any of the above-mentioned “anti-floating anchor construction devices with recoverable pile heads”, and then hoisting the anti-floating assembly into the casing 2.

[0058] The grouting pipe 5 is used to inject grout into the pile hole 9. In order to facilitate the arrangement of the grouting pipe 5, the positioning ring 7 is provided with an outer ring 7-1, a middle ring 7-2 and an inner ring 7-3 in a plane perpendicular to the anti-floating steel bar 3. The outer ring 7-1, the middle ring 7-2 and the inner ring 7-3 are all in a circular shape and the centers of the circles coincide. The outer diameter of the outer ring 7-1 is not greater than the inner diameter of the casing 2. The outer ring 7-1 and the middle ring 7-2 are connected by at least one connecting rod 7-4, and the middle ring 7-2 and the inner ring 7-3 are connected by at least one connecting rod 7-4. Each anti-floating steel bar 3 is fixed between the middle ring 7-2 and the inner ring 7-3. The grouting pipe 5 is arranged along the anti-floating steel bar 3 and is clamped in the inner ring 7-3 of each positioning ring 7. The grouting end of the grouting pipe 5 is located at the lower end of the anti-floating steel bar 3.

[0059] The entire section of the anti-floating steel bar 3 located in the pile hole 9 can be arranged with the flip embedding components 4 at intervals, and at this time, the flip embedding components 4 located in the soft stratum 8-2 are flipped and unfolded, and the flip embedding components 4 located in other strata are never flipped and unfolded; or, the section of the anti-floating steel bar 3 located in the soft stratum 8-2 is provided with the flip embedding components 4, and the section of the anti-floating steel bar 3 located in other strata is fixed with the fixed embedding components 6, and the fixed embedding components 6 are one or more, and the fixed embedding components 6 are located in the cylindrical range corresponding to the outer ring 7-1 of each positioning ring 7. Among them, the other strata are strata other than the soft stratum 8-2, including the hard stratum 8-1.

[0060] S6. Fill aggregate into the casing 2 and lift up the casing 2, using a method of filling aggregate in layers and gradually lifting up the casing 2 until the casing 2 is pulled out of the pile hole 9 and the pile hole 9 is filled with aggregate, and the movable steel bar 4-2 of the flip embedding assembly 4 is controlled to flip and unfold and insert into the soft stratum 8-2 outside the pile hole 9.

[0061] When filling aggregate in layers, the filling thickness needs to be controlled within a certain range to ensure that aggregate is uniformly and densely filled inside casing 2 to avoid voids. In order to facilitate the diffusion and dense filling of aggregate, aggregate is preferably pea stone, for example, aggregate is pea stone with a diameter of 0.5-2.0 cm, and after pea stone is filled in layers, it is also vibrated. After pea stone is filled to a certain thickness, pea stone is vibrated, and the purpose of vibration is to fill pea stone densely and diffuse pea stone around pile hole 9, then casing 2 is lifted to a certain height, so that the elevation of casing 2 bottom is slightly lower than the elevation of pea stone top, pea stone is filled and vibrated again, and repeated operation. After filling pea stone, hammering the top of casing 2 can also make pea stone become dense and diffuse in the surrounding strata. After casing 2 is pulled out from pile hole 9, pea stone should be supplemented in time to ensure the filling effect of pea stone in pile hole 9.

[0062] Several methods are provided below to control the active reinforcement 4-2 of the flip embedding assembly 4 to flip, unfold, and insert into the soft stratum 8-2 outside the pile hole 9. Method 1: When the lower end of the casing 2 corresponds to the position of the flip embedding assembly 4, that is, when the height of the lower end of the casing 2 is slightly greater than the corresponding height of the flip embedding assembly 4, the active reinforcement 4-2 of the flip embedding assembly 4 is flipped, unfolded, and inserted into the soft stratum 8-2 outside the pile hole 9 by pressing down or hammering the upper end of the casing 2. Method 2: When the lower end of the casing 2 exceeds the highest flip embedding assembly 4, it is generally selected to pull the casing 2 out of the pile hole 9, and then the active reinforcement 4-2 of each flip embedding assembly 4 is flipped, unfolded, and inserted into the soft stratum 8-2 outside the pile hole 9 by lifting the anti-floating reinforcement 3. Method 3: An elastic member is provided between the fixed reinforcement 4-1 and the active reinforcement 4-2 of the flip embedding assembly 4 to enable the active reinforcement 4-2 to automatically unfold, and the active reinforcement 4-2 is automatically unfolded during the lifting of the casing 2.

[0063] S7. Grout is poured into the pile hole 9 through the grouting pipe 5 and maintained, so that a poured solidified body 9-1 is formed inside the pile hole 9 and a rotary jet solidified body 9-2 is formed outside the pile hole 9. The poured solidified body 9-1 and the rotary jet solidified body 9-2 are solidified into a whole.

[0064] For example, the grouting slurry is mixed with ordinary Portland cement of grade P.0.42.5, the water-cement ratio of the slurry is 0.45-0.50, the slurry is pure cement slurry with a strength of M30, and the grouting pressure is 0.8-1.0MPa. When grouting the grouting slurry, when thick slurry emerges from the hole mouth, the grouting should be suspended, and the pressure should be re-pressed after a period of pause, for example, re-pressed after a pause of about 10 minutes. When the thick slurry emerges again, the grouting should be stopped. After the pile hole 9 is bored, the grouting should be completed within 24 hours. If secondary grouting is required, the grouting pressure should be greater than 2.0MPa. During the curing period, it is prohibited to touch the exposed anti-floating steel bars 3 with external force.

Claims

1. A method for constructing soft interlayer outward expansion type high pressure rotary grouting anti-floating piles, which is characterized in that: The steps include: S1, determining the position of the pile hole (9) and constructing the pile hole (9), wherein the pile hole (9) penetrates the hard stratum (8-1) from top to bottom and enters the soft stratum (8-2); S2, performing high-pressure rotary grouting from bottom to top in the pile hole (9); S3, assembling the pile head assembly (1) and the casing (2), so that the pile head (1-1) is threadedly connected to the lower end of the casing (2), and before the slurry of the high-pressure rotary spraying solidifies, the pile head assembly (1) and the casing (2) are inserted into the pile hole (9) by pressing down or hammering the upper end of the casing (2); The pile head assembly (1) comprises a pile head (1-1) and an operating rod (1-2); the lower section of the pile head (1-1) is conical and the upper section is cylindrical, and the bottom surface of the cone and the bottom surface of the cylinder have the same diameter and coincide with each other; the upper section of the pile head (1-1) is provided with an external thread; the center of the top surface of the upper section of the pile head (1-1) is fixedly connected to the operating rod (1-2), and the center line of the operating rod (1-2) coincides with the center line of the pile head (1-1); the casing (2) is a cylinder; the lower end of the casing (2) is provided with an internal thread that matches the external thread of the pile head (1-1), and the inner diameter of the casing (2) is not less than the diameter of the upper section of the pile head (1-1); S4, rotating the operating lever to disengage the pile head (1-1) from the casing (2), and taking the pile head assembly (1) out of the casing (2); S5, temporarily fixing the grouting pipe (5) in the anti-floating assembly, and then hoisting the anti-floating assembly into the casing (2), and providing a flip embedding assembly (4) in the section of the anti-floating steel bar (3) located in the soft stratum (8-2); The anti-floating component comprises an anti-floating steel bar (3), a positioning ring (7) and a flip embedding component (4), at least one anti-floating steel bar (3), each anti-floating steel bar (3) is fixed to the positioning ring (7), the positioning ring (7) comprises an outer ring (7-1), at least two positioning rings (7) are arranged at intervals, the diameter of the projection of the outer ring (7-1) of the positioning ring (7) on a cross section perpendicular to the anti-floating steel bar (3) is adapted to the inner diameter of the casing (2); at least one flip embedding component (4) is also fixed to the outer periphery of the anti-floating steel bar (3), the flip embedding component (4) comprises a fixed steel bar (4-1) and a movable steel bar (4-2), one end of the fixed steel bar (4-1) is fixedly connected to the anti-floating steel bar (3), and the fixed steel bar (4-1) and the anti-floating steel bar (3) are perpendicular to each other. The fixed steel bar (4-1) is straight, the other end of the fixed steel bar (4-1) is rotatably connected to the movable steel bar (4-2), the movable steel bar (4-2) can be rotated until the movable steel bar (4-2) is completely located within the cylindrical range corresponding to the outer ring (7-1) of each positioning ring (7), or can be rotated until the movable steel bar (4-2) is partially located outside the cylindrical range corresponding to the outer ring (7-1) of each positioning ring (7), the fixed steel bar (4-1) and the anti-floating steel bars (3) at both ends and the movable steel bar (4-2) are located in the same plane, the center line of the anti-floating steel bar (3) is set vertically, and the end of the anti-floating steel bar (3) inserted into the bottom of the pile hole (9) faces downward, and the rotation range of the movable steel bar (4-2) around the fixed steel bar (4-1) is located above the horizontal plane corresponding to the fixed steel bar (4-1); S6, filling aggregate into the casing (2) and lifting the casing (2), using a method of filling aggregate in layers and gradually lifting the casing (2), until the casing (2) is pulled out of the pile hole (9) and the pile hole (9) is filled with aggregate, and the movable steel bar (4-2) of the flip embedding component (4) is controlled to flip and unfold and insert into the soft stratum (8-2) outside the pile hole (9); S7. Grout is poured into the pile hole (9) through the grouting pipe (5) and maintained, so that a poured solidified body (9-1) is formed inside the pile hole (9) and a rotary jetted solidified body (9-2) is formed outside the pile hole (9), and the poured solidified body (9-1) and the rotary jetted solidified body (9-2) are solidified into a whole.

2. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to claim 1 is characterized by: In step S1, the pile hole (9) penetrates the soft stratum (8-2) and reaches or enters the good stratum (8-3) below the soft stratum (8-2), the hard stratum (8-1) is a pebble layer, the soft stratum (8-2) is a sand layer, and the good stratum (8-3) is a pebble layer or a bedrock layer.

3. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to claim 1 is characterized by: In step S3, the pile head (1-1) is made of metal, or the pile head (1-1) includes a metal shell and reinforced concrete inside the metal shell.

4. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to claim 1, characterized in that: In step S5, a first connection seat (4-3) is provided at one end of the fixed steel bar (4-1) of the flip embedding component (4) away from the anti-floating steel bar (3), the first connection seat (4-3) is provided with an axial hole which is perpendicular to both the fixed steel bar (4-1) and the anti-floating steel bar (3), a second connection seat (4-4) is provided at one end of the movable steel bar (4-2), the second connection seat (4-4) is provided with a rotating shaft which is passed through the axial hole, and the first connection seat (4-3) or the second connection seat (4-4) is also provided with a limit baffle (4-5) which limits the fixed steel bar (4-1) and the movable steel bar (4-2) to form a maximum angle and a minimum angle.

5. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to claim 4 is characterized by: In step S5, the maximum angle formed by the fixed steel bar (4-1) and the movable steel bar (4-2) is a straight angle, and the minimum angle formed by the fixed steel bar (4-1) and the movable steel bar (4-2) is a right angle or an obtuse angle.

6. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to claim 1, characterized in that: In step S5, the segments of the anti-floating steel bars (3) located in the pile hole (9) are arranged with flip embedding components (4) at intervals; or, the segments of the anti-floating steel bars (3) located in the soft stratum (8-2) are provided with at least one flip embedding component (4), and the segments of the anti-floating steel bars (3) located in other strata are fixed with at least one fixed embedding component (6), and the fixed embedding component (6) is located within the cylindrical range corresponding to the outer ring (7-1) of each positioning ring (7).

7. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to claim 6, characterized in that: In step S5, the fixed embedded component (6) includes a fixed tube (6-1) and at least one steel bar segment (6-2) fixed to the outer wall of the fixed tube (6-1), the anti-floating steel bar (3) is passed through the fixed tube (6-1) and fixed by welding, the steel bar segment (6-2) is perpendicular to the anti-floating steel bar (3), or one end of the steel bar segment (6-2) away from the anti-floating steel bar (3) is tilted upward and forms an acute angle with the anti-floating steel bar (3).

8. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to any one of claims 1 to 7, characterized in that: In step S5, the positioning ring (7) is provided with an outer ring (7-1), a middle ring (7-2) and an inner ring (7-3) in a plane perpendicular to the anti-floating steel bars (3); the outer ring (7-1), the middle ring (7-2) and the inner ring (7-3) are all in annular shape and their centers coincide with each other; the outer diameter of the outer ring (7-1) is not greater than the inner diameter of the casing (2); the outer ring (7-1) and the middle ring (7-2) are connected by at least one connecting rod (7-4); the middle ring (7-2) and the inner ring (7-3) are connected by at least one connecting rod (7-4); each anti-floating steel bar (3) is fixed between the middle ring (7-2) and the inner ring (7-3); a grouting pipe (5) is arranged along the anti-floating steel bars (3) and clamped in the inner ring (7-3); and a grouting outlet end of the grouting pipe (5) is located at the lower end of the anti-floating steel bars (3).

9. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to any one of claims 1 to 7, characterized in that: In step S6, when the lower end of the casing (2) corresponds to the position of the flip embedding component (4), the movable steel bars (4-2) of the flip embedding component (4) are flipped and unfolded and inserted into the soft stratum (8-2) outside the pile hole (9) by pressing down or hammering the upper end of the casing (2); or, when the lower end of the casing (2) exceeds the flip embedding component (4) at the highest position, the movable steel bars (4-2) of each flip embedding component (4) are flipped and unfolded and inserted into the soft stratum (8-2) outside the pile hole (9) by lifting the anti-floating steel bars (3); or an elastic member that enables the movable steel bars (4-2) to be automatically unfolded can be arranged between the fixed steel bars (4-1) of the flip embedding component (4) and the movable steel bars (4-2), and the movable steel bars (4-2) are automatically unfolded during the lifting of the casing (2).

10. The construction method of the soft interlayer outward expansion type high pressure rotary grouting anti-floating pile according to any one of claims 1 to 7, characterized in that: In step S6, the aggregate is pebbles with a diameter of 0.5 to 2.0 cm, and after the pebbles are filled in layers, vibration is also performed.

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