Construction method for cast-in-place pile in deep water

Abstract

The present invention relates to a construction method for deep-water bored cast-in-place piles, belonging to the technical field of engineering construction. The construction method for deep-water bored cast-in-place piles includes the following steps: transporting the pile: using a construction ship to tow the split casing structure floating on the water surface to the construction position; erecting the pile: rotating one end of the split casing structure downward in a vertical plane until the split casing structure is vertically arranged in the water; driving the pile: using a drop hammer installed on the construction ship to insert the permanent casing of the split casing structure vertically into the bottom soil layer; pouring concrete: pouring concrete into the pouring cavity inside the split casing structure to form a concrete pile; removing the removable casing: separating the removable casing from the permanent casing, and rotating the removable casing upward in a vertical plane until it floats on the water surface to recycle the removable casing. The construction method for deep-water bored cast-in-place piles has a short construction period, the removable casing can be recycled, and the construction cost is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering construction, and particularly relates to a construction method for cast-in-place piles in deep water. Background Art

[0002] The cast-in-place pile is a commonly used method for deep-water pile foundation construction. First, the casing is inserted deep into the water and vertically into the bottom soil layer, and then concrete is poured inside the casing. After the concrete pouring is completed, the casing is removed. At present, most methods use two crane ships to lift and suspend the casing, causing the floating casing to flip in the vertical plane, or use a single crane ship in cooperation with a pile-turning device or a pile-standing trolley to stand the pile. For deep-water cast-in-place pile construction, due to the large length of the casing, higher requirements are imposed on the lifting weight and height of the crane ship, increasing the difficulty of standing the casing. Moreover, since the casing needs to be inserted into the bottom soil layer and there is a concrete pile inside, at present, most methods use the method of cutting the casing in the middle to remove the casing. This method not only consumes high costs, but also the casing cannot be reused, resulting in waste of resources. Although Patent CN111926808A discloses a detachable casing structure for deep-water pile foundation and its construction method, which designs the casing structure as a steel casing and a sleeve, and uses the sleeve to insert into the bottom soil layer. After the concrete is poured, the steel casing is separated from the sleeve to achieve the reuse of the steel casing. Although the above detachable casing effectively solves the problem of non-reusability of the casing, due to the complex and difficult process of standing the casing in water at present, the reverse removal of the casing also faces similar difficulties and construction complexities, which undoubtedly increases the construction cost and construction period of deep-water pile foundation.

[0003] Therefore, designing a method for easily removing the casing from deep water is of great significance for the construction of cast-in-place piles in deep water. Summary of the Invention

[0004] In view of the deficiencies in the related art, the present invention provides a construction method for cast-in-place piles in deep water to simplify the construction method of cast-in-place piles in deep water, shorten the construction period and reduce the waste of resources during the construction process.

[0005] The present invention provides a construction method for cast-in-place piles in deep water, including the following steps:

[0006] Pile transportation: Use a construction ship to tow the split casing structure floating on the water surface to the construction position to be constructed;

[0007] Pile standing: Rotate one end of the split casing structure downward in the vertical plane until the split casing structure is vertically arranged in the water;

[0008] Pile driving: Use a percussion hammer installed on the construction ship to insert the permanent casing of the split casing structure vertically into the bottom soil layer;

[0009] Pour concrete: Pour concrete into the pouring cavity inside the split casing structure to form a concrete pile;

[0010] Demolish the removable casing: Separate the removable casing from the permanent casing in the split casing structure, and make the removable casing rotate upward in the vertical plane under the action of buoyancy and / or the pulling force of the construction ship until it floats on the water surface, so as to recover and recycle the removable casing.

[0011] This technical solution uses a construction ship to transport the split casing structure to the construction location to be constructed and vertically set the split casing structure in the water, reducing the time interval between transporting the pile and driving the pile of the split casing structure, shortening the construction period; by setting a percussion hammer to insert the permanent casing of the split casing structure into the bottom soil layer, thereby increasing the firmness of the connection between the concrete pile formed inside the split casing structure and the bottom soil layer; by separating the removable casing from the permanent casing in the split casing structure, the removable casing can be recovered and recycled, thereby reducing the construction cost.

[0012] In some embodiments, in the pile driving step, a drill installed on the construction ship is used to strike the bottom soil layer to assist the percussion hammer in inserting the permanent casing to a specified depth in the bottom soil layer.

[0013] In some embodiments, the removable casing and the permanent casing are detachably connected, and shear-resistant blocks are provided at the connection between the removable casing and the permanent casing to prevent relative rotation between the removable casing and the permanent casing when the drill strikes the bottom soil layer.

[0014] In some embodiments, the removable casing and the permanent casing are connected by a first steel wire rope; one end of the first steel wire rope is tied to the end of the removable casing away from the permanent casing, and the other end of the first steel wire rope passes through a lifting lug outside the permanent casing and is connected to the construction ship.

[0015] In some embodiments, in the pile driving step, the first steel wire rope binds the removable casing and the permanent casing tightly to make the removable casing and the permanent casing rigidly connected; in the step of demolishing the removable casing, the removable casing and the permanent casing are flexibly connected by the first steel wire rope to trail the removable casing.

[0016] In some embodiments, the construction ship is provided with a limiting groove extending in the left-right direction in the horizontal plane, and the split casing structure is arranged in the limiting groove to restrict the position of the split casing structure on the water surface.

[0017] In some embodiments, the split casing structure rotates in the vertical plane under the combined action of gravity and buoyancy; by adjusting the water inflow in the pouring cavity inside the split casing structure, the buoyancy and / or gravity received by the split casing structure is adjusted.

[0018] In some of these embodiments, during the pile driving step, the gravity acting on the split casing structure is greater than the buoyancy it receives; during the step of removing the removable casing, the gravity acting on the removable casing of the split casing structure is less than the buoyancy it receives.

[0019] In some of these embodiments, the construction vessel is further provided with a restraint assembly for restraining the movement of the split casing structure in the fore-and-aft direction of the construction vessel when it rotates downward.

[0020] In some of these embodiments, the construction vessel is equipped with a rotating mechanism, which is connected to the end of the removable casing away from the permanent casing to drive the split casing structure to rotate in a vertical plane.

[0021] Based on the above technical solutions, in the deep water bored pile construction method of the present invention, operations such as pile transportation, pile driving, pile hammering, and removal of the removable casing are carried out on the split casing structure by using a construction vessel and components such as a pile hammer installed on the construction vessel, so as to save the time interval between adjacent construction steps and shorten the construction period; and after the construction is completed, the removable casing is separated from the permanent casing to recycle and reuse the removable casing, thereby reducing the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 is a schematic structural diagram of the split casing structure and the construction vessel during the assembly of the deep water bored pile construction method of the present invention;

[0024] Figure 2 is a schematic structural diagram of the split casing structure and the construction vessel during the assembly of the deep water bored pile construction method of the present invention from another angle;

[0025] Figure 3 is Figure 2 a partial enlarged view of part A in

[0026] Figure 4 is a schematic structural diagram of the construction vessel in the deep water bored pile construction method of the present invention;

[0027] Figure 5 is a schematic structural diagram of the split casing structure during water surface transportation in the deep water bored pile construction method of the present invention;

[0028] Figure 6 is a schematic structural diagram of the split casing structure rotating downward in a vertical plane in the deep water bored pile construction method of the present invention;

[0029] Figure 7 This is a schematic structural diagram when the split casing structure in the construction method of the deep-water bored cast-in-place pile of the present invention is vertically arranged in water;

[0030] Figure 8 This is a schematic structural diagram when the construction of the vertical pile in the construction method of the deep-water bored cast-in-place pile of the present invention is completed;

[0031] Figure 9 This is a schematic structural diagram when pile driving construction is carried out in the construction method of the deep-water bored cast-in-place pile of the present invention;

[0032] Figure 10 This is a schematic structural diagram when the removable casing is separated from the permanent casing in the construction method of the deep-water bored cast-in-place pile of the present invention;

[0033] Figure 11 This is a schematic structural diagram when the removable casing horizontally moves in the construction method of the deep-water bored cast-in-place pile of the present invention;

[0034] Figure 12 This is a schematic structural diagram when the removable casing starts to rotate upward in the vertical plane in the construction method of the deep-water bored cast-in-place pile of the present invention;

[0035] Figure 13 This is a schematic structural diagram when the removable casing rotates upward by a certain angle in the vertical plane in the construction method of the deep-water bored cast-in-place pile of the present invention;

[0036] Figure 14 This is a schematic structural diagram when the removable casing floats on the water surface in the construction method of the deep-water bored cast-in-place pile of the present invention;

[0037] Figure 15 This is a schematic structural diagram after the first steel wire rope releases the connection between the removable casing and the permanent casing in the construction method of the deep-water bored cast-in-place pile of the present invention.

[0038] In the figure:

[0039] 1. Split casing structure; 2. Hull; 3. Gantry; 4. First winch; 5. Impact hammer; 6. Rotating mechanism; 7. Drill rig; 8. Second steel wire rope; 9. First steel wire rope; 10. Subaqueous soil layer;

[0040] 11. Removable casing; 12. Permanent casing; 13. Shear block;

[0041] 111. Casing connection part; 112. Second lifting lug; 113. Third lifting lug;

[0042] 121. First lifting lug; 21. Second winch; 22. Connector; 23. Limit groove;

[0043] 31. Hook. Detailed implementation manners

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "transverse", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0046] The terms "first", "second", "third", and "fourth" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", "third", and "fourth" may explicitly or implicitly include one or more of such features.

[0047] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] It should also be noted that for the convenience of scheming the construction process, the removable casing 11 is simplified in Figures 5 - 15 , and in Figures 1 - 15 , for the convenience of scheming the connection relationship and position state between the construction ship and the split casing structure 1 in a certain construction step, etc., on the premise of not affecting the understanding of the technical solution of the present invention, the components with low relevance to this construction step or not used in this construction step are simplified or omitted to varying degrees.

[0049] As shown in the Figures 1 - 15 accompanying drawings, in a schematic embodiment of the construction method of the deep-water bored cast-in-place pile of the present invention, the construction method of the deep-water bored cast-in-place pile includes the following steps:

[0050] Pile transportation: Use a construction vessel to tow the split casing structure 1 floating on the water surface to the construction location to be constructed;

[0051] Pile erection: Rotate one end of the split casing structure 1 downward in a vertical plane until the split casing structure 1 is vertically arranged in the water;

[0052] Pile driving: Use the impact hammer 5 installed on the construction vessel to insert the permanent casing 12 of the split casing structure 1 vertically into the bottom soil layer 10;

[0053] Concrete pouring: Pour concrete into the pouring cavity inside the split casing structure 1 to form a concrete pile;

[0054] Removing the removable casing 11: Separate the removable casing 11 in the split casing structure 1 from the permanent casing 12, so that the removable casing 11 rotates upward in a vertical plane under the action of buoyancy and / or the pulling force of the construction vessel until it floats on the water surface, so as to recover and recycle the removable casing 11.

[0055] In the above construction method of deep-water bored cast-in-place piles, as Figures 1 - 3 shown, the split casing structure 1 includes a permanent casing 12 and a removable casing 11; the removable casing 11 and the permanent casing 12 are coaxially arranged, and the inner parts of the removable casing 11 and the permanent casing 12 are respectively provided with through cavities extending along their axial directions. The through cavity inside the removable casing 11 is connected to the through cavity inside the permanent casing 12 and jointly forms a pouring cavity; the permanent casing 12 is inserted into the bottom soil layer 10, and by pouring concrete into the pouring cavity, a concrete pile is formed; one end of the removable casing 11 far from the permanent casing 12 is connected to the construction vessel, so that the construction vessel transports the split casing structure 1 to the construction location to be constructed through the removable casing 11, and inserts the permanent casing 12 into the bottom soil layer 10 through the removable casing 11.

[0056] In order to facilitate the separation of the removable casing 11 from the permanent casing 12, as Figure 2 and Figure 3As shown, a casing connecting portion 111 is provided at one end of the removable casing 11 close to the permanent casing 12, and the casing connecting portion 111 is detachably connected to the permanent casing 12 to facilitate the connection or separation of the removable casing 11 and the permanent casing 12; it should be noted that the permanent casing 12 and the removable casing 11 are also connected by a first steel wire rope 9, and the first steel wire rope 9 is wound or released by a first winch 4 installed on the construction vessel; the first steel wire rope 9 can both rigidly connect the permanent casing 12 and the removable casing 11 so that the two are firmly bound, and can also flexibly connect the two. Among them, in the piling step, the permanent casing 12 and the removable casing 11 are bound by the first steel wire rope 9 to increase the firmness of the connection between the permanent casing 12 and the removable casing 11, thereby facilitating the insertion of the permanent casing 12 into the underwater soil layer 10; and in the step of removing the removable casing 11, the permanent casing 12 and the removable casing 11 are flexibly connected by the first steel wire rope 9 to tail the removable casing 11.

[0057] In order to facilitate the first steel wire rope 9 to connect the permanent casing 12 and the removable casing 11, as shown in FIG. Figure 2 and Figure 3 As shown, the permanent casing 12 is provided with a first lifting lug 121, and the first lifting lug 121 is arranged on the outer periphery of the end of the permanent casing 12 away from the underwater soil layer 10; the removable casing 11 is provided with a second lifting lug 112 and a third lifting lug 113, the second lifting lug 112 is arranged corresponding to the first lifting lug 121 and is located at the end of the removable casing 11 close to the permanent casing 12, and the third lifting lug 113 is arranged corresponding to the second lifting lug 112 and is located at the end of the removable casing 11 away from the permanent casing 12; the end of the first wire rope 9 away from the first winch 4 is passed through the first lifting lug 121 and the second lifting lug 112 and then bound to the third lifting lug 113, so that the first wire rope 9 is connected to the removable casing 11 and the permanent casing 12 at the same time; in addition, it should be noted that two first winches 4 are installed on the construction vessel, and the two first winches 4 are connected to the two first wire ropes 9 are correspondingly connected and are respectively connected to the split casing structure 1 through the corresponding first steel wire ropes 9, so that the split casing structure 1 is force balanced; accordingly, the end of the permanent casing 12 away from the underwater soil layer 10 is provided with two first lifting ears 121, and the two first lifting ears 121 are symmetrically arranged on the outer periphery of the end of the permanent casing 12 away from the underwater soil layer 10; the end of the removable casing 11 connected to the permanent casing 12 is provided with two second lifting ears 112, and the two second lifting ears 112 are arranged in a corresponding position to the two first lifting ears 121 and are symmetrically arranged on the outer periphery of the end of the removable casing 11 connected to the permanent casing 12; the end of the removable casing 11 away from the permanent casing 12 is provided with two third lifting ears 113, and the two third lifting ears 113 are arranged in a corresponding position to the two second lifting ears 112 and are symmetrically arranged on the outer periphery of the end of the removable casing 11 away from the permanent casing 12.

[0058] In practical applications, due to the different water depths in different water areas, the lengths of the split casing structure 1 also vary. To increase the applicable range of the split casing structure 1, the detachable casing 11 includes several casing segments, and the several casing segments are detachably connected end to end, so that the length of the detachable casing 11 can be spliced according to the actual construction needs, thereby meeting the requirements of different water depths; the casing segment has a first end and a second end, and a segment connection part is provided at the second end, and the segment connection part is sleeved with the first end of the adjacent casing segment; it should be noted that the adjacent casing segments are connected and sealed with a sealing member to prevent the concrete from leaking from the gap between the adjacent casing segments during pouring; this belongs to the prior art in this field and will not be elaborated here.

[0059] In the above construction method of the deep-water bored cast-in-place pile, as Figure 4 shown, the construction ship includes a hull 2, a gantry 3, a rotating mechanism 6, a first winch 4 and a restraint assembly; the hull 2 is provided with a limiting groove 23 extending in the horizontal direction, and the limiting groove 23 penetrates the hull 2 in the vertical direction, and the limiting groove 23 is used to limit the position of the split casing structure 1 on the water surface; the gantry 3 is installed on the hull 2 and is located above the limiting groove 23, and the gantry 3 is connected with a hook 31 for hoisting or transporting the split casing structure 1; the rotating mechanism 6 is rotatably connected to the hull 2 and is arranged close to the limiting groove 23, and the rotating mechanism 6 is connected to the end of the detachable casing 11 far from the permanent casing 12, so that the split casing structure 1 is rotatably connected to the hull 2 through the rotating mechanism 6, thereby facilitating the rotation of the split casing structure 1 in the vertical plane; the rotating mechanism 6 belongs to the prior art and will not be elaborated here; the first winch 4 is installed on the hull 2 and is used for winding or releasing the first steel wire rope 9 and connecting with the split casing structure 1 through the first steel wire rope 9; it should be noted that the limiting groove 23 extends in the left-right direction of the hull 2 in the horizontal plane, and the two first winches 4 are symmetrically arranged on both sides before and after the limiting groove 23; and in order to facilitate the transportation of the split casing structure 1, a notch is provided on the left side of the limiting groove 23 to facilitate the split casing structure 1 to extend into the limiting groove 23; the notch is opened on the hull 2 and extends in the direction away from the rotating mechanism 6; the restraint assembly is used to restrain the direction of the split casing structure 1 during the vertical pile construction to prevent the split casing structure 1 from tilting in the front-back direction of the hull 2.

[0060] In some embodiments, as Figure 1 and Figure 7As shown in the figure, the restraint assembly includes a second winch 21 and a second steel wire rope 8. The second winch 21 is installed on the hull 2 and is used to wind or release the second steel wire rope 8. The split casing structure 1 is connected to the hull 2 through the second steel wire rope 8 to use the second steel wire rope 8 to restrain the direction of the split casing structure 1 during the pile driving construction process. It should be noted that in order to make the split casing structure 1 receive uniform force, second winches 21 are symmetrically arranged on the front and rear sides of the limit groove 23. The two second winches 21 are correspondingly connected to two second steel wire ropes 8 and are respectively connected to the split casing structure 1 through the corresponding second steel wire ropes 8. In order to facilitate the connection or separation of the second steel wire rope 8 and the split casing structure 1, the split casing structure 1 is provided with a fourth lifting lug, and a connecting piece 22 is provided on the hull 2. One end of the second steel wire rope 8 away from the second winch 21 passes through the fourth lifting lug and is connected to the connecting piece 22. The connecting piece 22 is used to bind the second steel wire rope 8. The connecting piece 22 is correspondingly arranged with the second winch 21 and is located on the left side of the hull 2. It should also be noted that the fourth lifting lug is arranged at one end of the split casing structure 1 away from the rotating mechanism 6, so that the connecting piece 22, the connection part of the split casing structure 1 and the rotating mechanism 6, and the fourth lifting lug are distributed in a triangle in the vertical plane, so that the second steel wire rope 8 exerts a force inclined in the vertical plane on the split casing structure 1 during the pile driving construction of the split casing structure 1, preventing the split casing structure 1 from tilting in the front and rear directions of the hull 2, thereby restraining the direction of the pile driving construction of the split casing structure 1. And by controlling the speed at which the second winch 21 releases the second steel wire rope 8, the rotation direction of the split casing structure 1 in the vertical plane can also be controlled. In addition, it should be noted that in some embodiments, the fourth lifting lug is the second lifting lug 112, that is, the second lifting lug 112 is connected to both the first steel wire rope 9 and the second steel wire rope 8 to simplify the structure of the detachable casing 11.

[0061] In the above-mentioned construction method of deep water cast-in-place pile, a pile gripper and a percussion hammer 5 are also installed on the hull 2. The pile gripper is connected to one end of the detachable casing 11 away from the permanent casing 12 and is arranged close to the limit groove 23 to grip the detachable casing 11 to prevent the split casing structure 1 from tilting after pile driving or during the pile driving process. The percussion hammer 5 is used to apply a downward acting force on the split casing structure 1 to insert the permanent casing 12 into the bottom soil layer 10. In actual construction, relying solely on the impact of the percussion hammer 5 may not be able to insert the permanent casing 12 to a specific depth, especially in the case where the bottom soil layer 10 contains rocks, etc. To solve this problem, as Figure 2As shown in the figure, a drilling rig 7 is installed on the hull 2 near the gantry 3. The drilling rig 7 drills the bottom soil layer 10 to soften the bottom soil layer 10 or form a pile hole, so as to facilitate the impact hammer 5 to insert the permanent casing 12 into the bottom soil layer 10, and then insert the permanent casing 12 to a specified depth in the bottom soil layer 10. It should be noted that in order to prevent the detachable casing 11 and the permanent casing 12 from rotating relative to each other axially during the drilling of the drilling rig 7 into the rock, a shear block 13 is provided between the detachable casing 11 and the permanent casing 12.

[0062] Taking the construction of the water intake of the Yellow River Diversion to Jining Project in Qinghai Province as an example, the construction method of the deep water bored pile using the construction ship and the split casing structure 1 will be introduced in detail. The construction method of the deep water bored pile specifically includes the following steps:

[0063] Pile transportation: Adjust the water inflow in the pouring cavity of the split casing structure 1 so that the buoyancy received by the split casing structure 1 is greater than its own gravity, so that the split casing structure 1 floats on the water surface; The split casing structure 1 is extended from the notch into the limit groove 23 by a tugboat to limit the position of the split casing structure 1 on the water surface; One end of the detachable casing 11 far from the permanent casing 12 is connected to the rotating mechanism 6 and the hook 31, so as to transport the split casing structure 1 to the construction position under the action of the pulling force of the hook 31 and the deep water buoyancy.

[0064] Pile erection: Connect the second steel wire rope 8 with the second winch 21, the connecting piece 22 and the split casing structure 1; Reduce the buoyancy received by the split casing structure 1 so that the split casing structure 1 rotates vertically downward until the split casing structure 1 is vertically arranged in the water; When the split casing structure 1 starts to rotate vertically downward, the second winch 21 releases the second steel wire rope 8 to prevent the split casing structure 1 from tilting in the front-back direction of the hull 2; And the hook 31 pulls up one end of the detachable casing 11 far from the permanent casing 12 to prevent the permanent casing 12 from contacting the bottom soil layer 10 and damaging the permanent casing 12.

[0065] Pile driving: After the verticality test of the split casing structure 1 is completed and the verticality of the split casing structure 1 meets the construction requirements, the connection between the second steel wire rope 8 and the connecting piece 22 is released, and the second hoist 21 reels the second steel wire rope 8 to disengage the second steel wire rope 8 from the fourth lifting eye, thereby releasing the constraint of the second steel wire rope 8 on the split casing structure 1; the first hoist 4 reels the first steel wire rope 9 to tighten the first steel wire rope 9 to increase the firmness of the connection between the removable casing 11 and the permanent casing 12; the pile gripper and the impact hammer 5 cooperate with each other, the pile gripper grips the removable casing 11, and the impact hammer 5 hammers the removable casing 11 to insert the permanent casing 12 Underwater soil layer 10; after the impact hammer 5 hammers the removable casing 11 for a period of time, if the depth of the permanent casing 12 inserted into the underwater soil layer 10 remains unchanged and has not reached the construction design depth, after the drilling rig 7 drills the underwater soil layer 10, the impact hammer 5 continues to hammer the removable casing 11 to increase the depth of the permanent casing 12 inserted into the underwater soil layer 10; if the depth of the permanent casing 12 inserted into the underwater soil layer 10 no longer changes and has not reached the construction design depth after the impact hammer 5 continues to hammer for a period of time, the drilling rig 7 drills the underwater soil layer 10 again, and the impact hammer 5 continues to hammer the removable casing 11, and the cycle is repeated until the depth of the permanent casing 12 inserted into the underwater soil layer 10 meets the construction requirements.

[0066] Pouring concrete: concrete is poured into the through cavity of the split casing structure 1 through a grouting pipe provided on the construction vessel to form a concrete pile.

[0067] Removing the removable casing: the first winch 4 releases the first steel wire rope 9, and the hook 31 pulls the removable casing 11 vertically upward until the removable casing 11 is separated from the concrete pile; then the construction vessel moves horizontally to drive the removable casing 11 to move horizontally; the buoyancy of the removable casing 11 is increased, and the end of the removable casing 11 away from the construction vessel is rotated upward in the vertical direction until the removable casing 11 floats on the water surface in the horizontal direction; the connection between the first steel wire rope 9 and the third lifting eye 113 is released, and the first winch 4 reels the first steel wire rope 9 to disengage the first steel wire rope 9 from the first lifting eye 121 and the second lifting eye 112, thereby releasing the connection between the removable casing 11 and the permanent casing 12; the removable casing 11 is recovered and recycled.

[0068] The above-mentioned deep-water bored pile construction method utilizes a split casing structure 1 for construction, and utilizes a removable casing 11 to be connected to a construction vessel so as to facilitate the insertion of a permanent casing 12 into the underwater soil layer 10; by separating the removable casing 11 from the permanent casing 12 after the construction is completed, the removable casing 11 can be recycled, thereby reducing the construction cost; and the method for disassembling and separating the permanent casing 12 and the removable casing 11 is simple and easy to operate.

[0069] Finally, it should be noted that the embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features. Without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A construction method for deep-water bored cast-in-place piles, characterized in that, It includes the following steps: Pile transportation: Use a construction ship to tow the split casing structure floating on the water surface to the construction position to be constructed; Pile erection: Rotate one end of the split casing structure downward in the vertical plane until the split casing structure is vertically arranged in the water; Pile driving: Use the impact hammer installed on the construction ship to insert the permanent casing of the split casing structure into the bottom soil layer in the vertical direction; Concrete pouring: Pour concrete into the pouring cavity inside the split casing structure to form a concrete pile; Removing the removable casing: Separate the removable casing in the split casing structure from the permanent casing, so that the removable casing rotates upward in the vertical plane under the action of buoyancy and / or the pulling force of the construction ship until it floats on the water surface, so as to recover and recycle the removable casing; Wherein, the removable casing is connected to the permanent casing by a first steel wire rope; one end of the first steel wire rope is bound to the end of the removable casing far away from the permanent casing, and the other end of the first steel wire rope passes through the lifting lug outside the permanent casing and is connected to the construction ship; In the pile driving step, the first steel wire rope binds and fastens the removable casing and the permanent casing, so that the removable casing and the permanent casing are rigidly connected; in the step of removing the removable casing, the removable casing and the permanent casing are flexibly connected by the first steel wire rope to perform tail sliding on the removable casing.

2. The construction method of the deep-water bored cast-in-place pile according to claim 1, characterized in that, In the pile driving step, use the drill installed on the construction ship to strike the bottom soil layer to assist the impact hammer to insert the permanent casing to the specified depth of the bottom soil layer.

3. The construction method of the deep-water bored cast-in-place pile according to claim 2, characterized in that, The removable casing and the permanent casing are detachably connected, and shear blocks are provided at the connection between the removable casing and the permanent casing to prevent relative rotation between the removable casing and the permanent casing when the drill strikes the bottom soil layer.

4. The construction method of the deep-water bored cast-in-place pile according to claim 1, characterized in that, The construction ship is provided with a limiting groove extending in the left-right direction in the horizontal plane, and the split casing structure is arranged in the limiting groove to restrict the position of the split casing structure on the water surface.

5. The construction method of the deep-water bored cast-in-place pile according to claim 1, characterized in that, The split casing structure rotates in the vertical plane under the combined action of gravity and buoyancy; by adjusting the water inflow in the pouring cavity inside the split casing structure, the buoyancy and / or gravity received by the split casing structure is adjusted.

6. The construction method of the deep-water bored cast-in-place pile according to claim 5, characterized in that In the pile erection step, the gravity received by the split casing structure is greater than the buoyancy it receives; in the step of removing the removable casing, the gravity received by the removable casing of the split casing structure is less than the buoyancy it receives.

7. The construction method of the deep-water bored cast-in-place pile according to claim 1, characterized in that, The construction ship is also provided with a restraint assembly, and the restraint assembly is used to restrain the movement of the split casing structure in the front-rear direction of the construction ship when it rotates downward.

8. The construction method of the deep-water bored cast-in-place pile according to claim 1, characterized in that, The construction ship is installed with a rotating mechanism, and the rotating mechanism is connected to the end of the removable casing far away from the permanent casing to drive the split casing structure to rotate in the vertical plane.

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