Grouting method and device for bored piles in sandy and gravel soil layers

Abstract

The present invention discloses a grouting method and device for bored tank pile injection in sand-egg soil layer, which comprises the following steps: arranging a plurality of grouting pipes in a steel cage, and starting from the completion time of the last grouting, after an interval of a preset time, inputting a preset amount of cement slurry in a cement mortar pool into each grouting pipe through a grouting pump via a grouting pipe, and after the last grouting, inputting the cement slurry in the cement mortar pool into each grouting pipe via a grouting pump via a grouting pipe until the cement slurry seeps out of the ground, wherein the preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting, which is completely different from the traditional grouting technology, and the present invention avoids the problem that the cement slurry at the bottom of the pile is easily diffused due to the uninterrupted one-time grouting of the grouting pipe in the traditional grouting technology, and cannot form an effective whole with the pile head, and is likely to cause the cement slurry to flow to other pile bottoms, resulting in the grouting amount of other piles failing to meet the requirements.

Description

Technical Field

[0001] The invention relates to the field of grouting, and in particular to a grouting method and device for bored tank piles in sandy gravel layers. Background Art

[0002] In view of the geological conditions of the sand and gravel layer, the traditional grouting technology is to carry out uninterrupted one-time grouting in the grouting pipe, and the grouting is terminated when the grouting volume reaches the design requirements. This grouting method easily causes the cement slurry at the bottom of the pile to be diffuse, and it cannot form an effective whole with the pile head, and it is very likely to flow to the bottom of other piles, causing the grouting volume of other piles to fail to meet the requirements. Summary of the invention

[0003] In order to solve the problem that the cement slurry at the bottom of the pile is easily diffused and cannot form an effective whole with the pile head due to the uninterrupted one-time grouting of the grouting pipe in the traditional grouting technology, the present invention proposes a grouting method for sand-pebble soil layer bored pot pile, which is characterized in that the cement slurry of a preset proportion is injected into the bottom of the bored pot pile for multiple times through the grouting equipment, so that the cement slurry penetrates into the sand-pebble layer around the pile head of the bored pot pile; the grouting equipment comprises a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence; the method comprises the steps of:

[0004] S1: The drilling rig is in place and drilling is performed to form a pile hole;

[0005] S2: placing a steel cage in the pile hole, wherein a plurality of grouting pipes are arranged on the steel cage, wherein the grouting pipes are arranged perpendicular to the ground along the length direction of the steel cage and are fixedly connected to the steel cage; the end of the grouting pipe close to the ground is higher than the ground by a preset length, and the end away from the ground is down to the bottom of the pile hole and is longer than the preset length of the steel cage;

[0006] S3: pouring concrete into the steel cage to form bored cast-in-place piles;

[0007] S4: within the first preset period after pouring concrete, flush each grouting pipe with clean water of preset pressure by a high-pressure pump to complete the unplugging of the grouting pipe;

[0008] S5: After the plugging is completed and within the second preset time period after the concrete is poured, a preset amount of cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump through a grouting pipe to complete the first grouting of the grouting pipe, and the number of grouting times is increased by 1; it is determined whether the number of grouting times is equal to the preset number of grouting times, if so, the process proceeds to step S7, if not, the process proceeds to step S6;

[0009] S6: After a preset time interval from the moment when the last grouting of the grouting pipe is completed, a preset amount of cement slurry in the cement mortar pool is again input into each grouting pipe through a grouting pump through a grouting pipe to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1;

[0010] S7: Determine whether the number of grouting times is equal to the preset number of grouting times. If not, repeat step S6. If so, enter the last grouting of the grouting pipe. The method of the last grouting is specifically as follows: starting from the completion time of the last grouting, after a preset time interval, the cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump using a grouting pipe until the cement slurry seeps out of the ground. The preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting.

[0011] Furthermore, before step S1, the following steps are also included:

[0012] Digging a hole at a predetermined pile position to place a casing above the ground, wherein the length of the casing is less than the length of the steel cage and the diameter of the casing is greater than the designed pile diameter of the bored pile; filling the gap between the outer wall of the casing and the hole wall, and compacting in layers;

[0013] The step S1 specifically includes: the drilling machine is positioned and drilling is performed according to the positioning of the casing to form a pile hole;

[0014] In the step S2, the steel cage is placed in the casing;

[0015] The step between step S1 and step S2 also includes: cleaning the pile hole, specifically:

[0016] S11: The sediment in the pile hole is extracted by a grout pump and casing to complete the cleaning of the pile hole.

[0017] Furthermore, between step S2 and step S3, the process further includes: cleaning the pile hole, specifically:

[0018] S21: pumping the slurry in the pile hole to the slurry pool through a conduit arranged in the steel cage and a slurry pump connected to the conduit;

[0019] S22: The depth of the current pile hole is obtained by lowering the measuring rope method. When the depth of the current pile hole is less than the designed pile hole depth, grouting is performed again through step S21 until the depth of the current pile hole is greater than the designed pile hole depth.

[0020] Furthermore, one end of the steel cage close to the ground is higher than the ground; and a plurality of grouting holes are provided on a preset length of one end of the grouting pipe away from the ground.

[0021] The present invention also proposes a grouting device for bored piles in sandy soil layers, which injects cement slurry of a preset proportion into the bottom of the bored pile several times through the grouting equipment, so that the cement slurry penetrates into the sandy and gravel layer around the pile head of the bored pile; the grouting equipment comprises a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence; the device comprises:

[0022] A drilling module, used for drilling holes to form pile holes;

[0023] A steel cage placement module is used to place the steel cage in the pile hole. The steel cage is provided with a plurality of grouting pipes, which are arranged perpendicular to the ground along the length direction of the steel cage and are fixedly connected to the steel cage; one end of the grouting pipe close to the ground is higher than the ground by a preset length, and the other end away from the ground is down to the bottom of the pile hole and is longer than the preset length of the steel cage;

[0024] A pouring module, used to pour concrete into the steel cage to form bored cast-in-place piles;

[0025] The unplugging module is used to flush each grouting pipe with clean water of preset pressure by a high-pressure pump within the first preset period after pouring concrete, so as to complete the unplugging of the grouting pipe;

[0026] The initial grouting module is used to, after the plugging is completed and within the second preset period after the concrete is poured, use the grouting pump to input the preset amount of cement slurry in the cement mortar pool into each grouting pipe through the grouting pipe to complete the first grouting of the grouting pipe, and the number of grouting times is increased by 1; when the number of grouting times is equal to the preset number of grouting times, the last grouting is performed through the grouting completion module; when the number of grouting times is not equal to the preset number of grouting times, the next grouting is performed through the grouting module;

[0027] The grouting module is used to, after a preset time interval from the completion time of the last grouting of the grouting pipe, input a preset amount of cement slurry in the cement mortar pool into each grouting pipe again through the grouting pipe through the grouting pump to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1;

[0028] The grouting completion module is used to enter the grouting pipe for the last grouting when the number of grouting injections is equal to the preset number of grouting injections; when the number of grouting injections is not equal to the preset number of grouting injections, the next grouting is performed through the grouting module; the last grouting is specifically as follows: from the completion time of the last grouting, after an interval of preset time, the cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump using a grouting pipe until the cement slurry seeps out of the ground; the preset time interval is less than the initial setting time of the corresponding cement slurry during the last grouting.

[0029] Furthermore, before the drilling, the process further comprises:

[0030] Digging a hole at a predetermined pile position to place a casing above the ground, wherein the length of the casing is less than the length of the steel cage and the diameter of the casing is greater than the designed pile diameter of the bored pile; filling the gap between the outer wall of the casing and the hole wall, and compacting in layers;

[0031] The drilling module is specifically used to drill holes according to the positioning of the casing to form pile holes;

[0032] In the reinforcement cage placement module, the reinforcement cage is placed in the casing;

[0033] The device also includes:

[0034] The first hole cleaning module is used to extract the sediment in the pile hole through the slurry pump and the casing to complete the cleaning of the pile hole.

[0035] Furthermore, the device also includes a device for placing the steel cage and before pouring concrete:

[0036] The second hole cleaning module specifically comprises:

[0037] The slurry pumping unit is used to pump the slurry in the pile hole to the slurry pool through a conduit arranged in the steel cage and a slurry pump connected to the conduit;

[0038] The measurement module is used to obtain the depth of the current pile hole by lowering the measuring rope method. When the depth of the current pile hole is less than the designed pile hole depth, the grouting unit is used to pump grout again until the depth of the current pile hole is greater than the designed pile hole depth.

[0039] Furthermore, one end of the steel cage close to the ground is higher than the ground; and a plurality of grouting holes are provided on a preset length of one end of the grouting pipe away from the ground.

[0040] Compared with the prior art, the present invention has at least the following beneficial effects:

[0041] The present invention arranges a plurality of grouting pipes in a steel cage, and after a preset time interval from the completion time of the last grouting, a preset amount of cement slurry in a cement mortar pool is input into each grouting pipe through a grouting pump by means of a grouting pipe, the number of grouting times is increased by 1, until the number of grouting times is equal to the preset number of grouting times, and the last grouting of the grouting pipe is performed, and in the process of the last grouting, the cement slurry in the cement mortar pool is input into each grouting pipe by means of a grouting pump by means of a grouting pipe, until the cement slurry seeps out of the ground, wherein the preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting, which is completely different from the traditional grouting technology, and the present invention completely avoids the uninterrupted one-time grouting of the grouting pipe in the traditional grouting technology (the grouting pressure is relatively large), and the grouting is terminated when the grouting amount reaches the design requirement, and the cement slurry at the bottom of the pile is easily diffused and cannot form an effective whole with the pile head (causing the pile foundation bearing capacity to be inconsistent with the design), and it is very likely to cause the cement slurry to flow to the bottoms of other piles, resulting in the problem that the grouting amount of other piles cannot meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flow chart of a grouting method for bored tank piles in sandy and gravel soil layers;

[0043] Figure 2 It is a structural diagram of a grouting device for bored tank pile injection in sandy and gravel soil layers;

[0044] Figure 3 This is the grouting status diagram of the first grouting pipe;

[0045] Figure 4 This is the grouting status diagram of the second grouting pipe;

[0046] Figure 5 Setting diagram for grouting pipe bending. DETAILED DESCRIPTION

[0047] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0048] Embodiment 1

[0049] In order to solve the problem that the cement slurry at the bottom of the pile is easily diffused and cannot form an effective whole with the pile head by continuous one-time grouting of the grouting pipe in the traditional grouting technology, Figure 1 , Figure 3 and Figure 4As shown, this embodiment takes two grouting pipes (1# grouting pipe and 2# grouting pipe) arranged in a steel cage and performs grouting twice as an example, and proposes a grouting method for bored piles in a sandy soil layer, wherein cement slurry of a preset proportion is injected into the bottom of the bored pile several times through a grouting device, so that the cement slurry penetrates into the sandy soil layer around the pile head of the bored pile; the grouting device comprises a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence (the grouting pump is connected to the cement mortar pool through a grouting pipe, see Figure 3 and Figure 4 ); the method comprises the steps of:

[0050] The step S1 also includes:

[0051] Dig a hole at the predetermined pile position to place a casing above the ground (the casing is 0.5m above the ground), the length of the casing is less than the length of the steel cage, and the diameter of the casing is greater than the designed pile diameter of the bored pile; fill the gap between the outer wall of the casing and the hole wall, and compact it layer by layer;

[0052] S1: The drilling rig is in place and drilling is performed to form a pile hole;

[0053] The step S1 specifically includes: the drilling machine is positioned and drilling is performed according to the positioning of the casing to form a pile hole;

[0054] The step between step S1 and step S2 also includes: cleaning the pile hole, specifically:

[0055] S11: The sediment in the pile hole is extracted by a grout pump and casing to complete the cleaning of the pile hole.

[0056] S2: A steel cage is placed in the pile hole, and a plurality of grouting pipes are arranged on the steel cage. The grouting pipes are arranged perpendicular to the ground along the length direction of the steel cage and are fixedly connected to the steel cage; one end of the grouting pipe close to the ground is higher than the ground by a preset length (50 cm), and the other end away from the ground is lowered to the bottom of the pile hole and is longer than the preset length (20 cm) of the steel cage;

[0057] In the step S2, the steel cage is specifically placed in the casing;

[0058] The two grouting pipes in this embodiment need to be symmetrically arranged on the circumference of the steel cage, and welded or tied to the nearest steel bars (the steel bars in the steel cage), and the fixed spacing between the two grouting pipes is not greater than 1.2 meters.

[0059] The end of the steel cage close to the ground is higher than the ground; a plurality of drill holes are arranged on a preset length (20 cm) of the end of the grouting pipe away from the ground, each drill hole is arranged in a plum blossom shape, and the drill hole diameter is 5-8 mm.

[0060] It should be noted that the grouting pipe of this embodiment uses two welded steel pipes with a diameter of 25 mm and a wall thickness of 3.2 mm, and each section of the steel pipe is connected by an external connection. Before installing the grouting pipe on the steel cage, it is necessary to clean the debris in the grouting pipe to prevent clogging the grouting hole (drilling hole), and seal the end of the grouting pipe close to the ground with a plug (opened during grouting to connect the grouting pipe).

[0061] The step between step S2 and step S3 also includes: cleaning the pile hole, specifically:

[0062] S21: The slurry in the pile hole is pumped into the slurry pool through a conduit arranged in the steel cage (the conduit must be lowered to the bottom of the hole to avoid inadequate hole cleaning) and a slurry pump connected to the conduit;

[0063] S22: The depth of the current pile hole is obtained by lowering the measuring rope method. When the depth of the current pile hole is less than the designed pile hole depth, grouting is performed again through step S21 until the depth of the current pile hole is greater than the designed pile hole depth.

[0064] S3: pouring concrete into the steel cage to form bored cast-in-place piles;

[0065] S4: In the first preset period (1st to 2nd day) after pouring concrete, a high-pressure pump (ZB-2 three-cylinder plunger mortar pump, the maximum working pressure of which is 8Mpa, and the slurry output is 3-5 cubic meters / hour) is used to pressurize the grouting pipe with clean water of a preset pressure (0.5-3.0Mpa) to complete the unplugging of the grouting pipe;

[0066] In this embodiment, the water-cement ratio of cement slurry is: 42.5# ordinary Portland cement slurry is used for cement, and the water-cement ratio is 0.45-0.65; in order to avoid clogging of the grouting pipe during the first grouting, the water-cement ratio can be appropriately increased. According to the set water-cement ratio, the required water-cement ratio is obtained, and a grouting liquid storage pool is dug next to the grouting pump, and the cement and water of the set ratio are poured in and mixed evenly to form a cement mortar pool.

[0067] S5: After the plugging is completed and within the second preset period (2nd to 28th day) after the concrete is poured, the preset amount of cement slurry in the cement mortar pool is pumped into each grouting pipe through the grouting pipe by the grouting pump to complete the first grouting of each grouting pipe (see Figure 3 ); the grouting pressure of the first grouting can be appropriately reduced, generally 1-3MPa, and the amount of cement slurry input is 30%-40% of the designed amount; the number of grouting times is increased by 1; it is determined whether the number of grouting times is equal to the preset number of grouting times (in this embodiment, the initial value of the number of grouting times is set to 1, and the preset number of grouting times is set to 2), if so, it goes to step S7, if not, it goes to step S6;

[0068] S6: After a preset time interval from the moment when the last grouting of the grouting pipe is completed, a preset amount of cement slurry in the cement mortar pool is again input into each grouting pipe through a grouting pump through a grouting pipe to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1;

[0069] S7: Determine whether the number of groutings is equal to the preset number of groutings. If not, repeat step S6. If yes, enter the last grouting of the grouting pipe. The method of the last grouting is as follows: after the completion time of the last grouting, after the preset time interval, the cement slurry in the cement mortar pool is input into each grouting pipe through the grouting pump through the grouting pipe until the cement slurry seeps out of the ground. The preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting. Since this embodiment is illustrated by two groutings, the last grouting of this embodiment is the second grouting. Figure 4 .

[0070] In this embodiment, the preset time of the interval is 15-30 minutes, which shall not exceed the initial setting time of the cement slurry corresponding to the last grouting (i.e. 45 minutes). During the last grouting, the grouting pressure is increased and the remaining cement slurry is injected until the surface returns to the grout.

[0071] It should be noted that for bored tank piles with a pile diameter exceeding 1200mm and a pile length exceeding 15m, or a grouting volume exceeding 4 tons, 3 or more grouting pipes can be set for grouting.

[0072] This embodiment of Figure 3 The grouting layer formed after the first grouting is reflected in the figure; Figure 4 The grouting layer formed after the second grouting is reflected in the figure. Figure 4 The color of the middle grouting layer is relatively Figure 3 The color of the middle grouting layer should be lighter to distinguish the grouting layer formed after the first grouting from the grouting layer formed after the second grouting.

[0073] This embodiment adopts multiple grouting methods (first grouting and second grouting). In the first grouting, the grouting pressure is relatively small, and the grouting amount (cement slurry input) is 30%-40% of the designed amount, which is used to fill the pores of the sand and egg layer near the bottom of the bored pile, and form a whole with the pile end. The second grouting is separated from the first grouting for a period of time, but it must not exceed the cement initial setting time of the first grouting. The grouting pressure gradually increases with time, and the cement and sand and gravel further form a whole and wrap with the pile head. Then the slurry flows up along the pile wall until it returns to the ground, and the grouting ends. The cement, sand and gravel and the pile head wrap to form an effective overall structure, which can increase the bearing capacity of the pile foundation by 30%-40% and reduce the settlement by 30% compared with the traditional one-time grouting method.

[0074] Embodiment 2

[0075] like Figure 2 As shown, the present invention also proposes a grouting device for bored piles in sandy soil layers, which injects cement slurry of a preset proportion into the bottom of the bored pile several times through the grouting equipment, so that the cement slurry penetrates into the sandy and gravel layer around the pile head of the bored pile; the grouting equipment includes a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence; the device includes:

[0076] A drilling module, used for drilling holes to form pile holes;

[0077] A steel cage placement module is used to place the steel cage in the pile hole. The steel cage is provided with a plurality of grouting pipes, which are arranged perpendicular to the ground along the length direction of the steel cage and are fixedly connected to the steel cage; one end of the grouting pipe close to the ground is higher than the ground by a preset length, and the other end away from the ground is down to the bottom of the pile hole and is longer than the preset length of the steel cage;

[0078] A pouring module, used to pour concrete into the steel cage to form bored cast-in-place piles;

[0079] The unplugging module is used to flush each grouting pipe with clean water of preset pressure by a high-pressure pump within the first preset period after pouring concrete, so as to complete the unplugging of the grouting pipe;

[0080] The initial grouting module is used to, after the plugging is completed and within the second preset period after the concrete is poured, use the grouting pump to input the preset amount of cement slurry in the cement mortar pool into each grouting pipe through the grouting pipe to complete the first grouting of the grouting pipe, and the number of grouting times is increased by 1; when the number of grouting times is equal to the preset number of grouting times, the last grouting is performed through the grouting completion module; when the number of grouting times is not equal to the preset number of grouting times, the next grouting is performed through the grouting module;

[0081] The grouting module is used to, after a preset time interval from the completion time of the last grouting of the grouting pipe, input a preset amount of cement slurry in the cement mortar pool into each grouting pipe again through the grouting pipe through the grouting pump to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1;

[0082] The grouting completion module is used to enter the grouting pipe for the last grouting when the number of grouting injections is equal to the preset number of grouting injections; when the number of grouting injections is not equal to the preset number of grouting injections, the next grouting is performed through the grouting module; the last grouting is specifically as follows: from the completion time of the last grouting, after an interval of preset time, the cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump using a grouting pipe until the cement slurry seeps out of the ground; the preset time interval is less than the initial setting time of the corresponding cement slurry during the last grouting.

[0083] The drilling process also includes:

[0084] Digging a hole at a predetermined pile position to place a casing above the ground, wherein the length of the casing is less than the length of the steel cage and the diameter of the casing is greater than the designed pile diameter of the bored pile; filling the gap between the outer wall of the casing and the hole wall, and compacting in layers;

[0085] The drilling module is specifically used to drill holes according to the positioning of the casing to form pile holes;

[0086] In the reinforcement cage placement module, the reinforcement cage is placed in the casing;

[0087] The device also includes:

[0088] The first hole cleaning module is used to extract the sediment in the pile hole through the slurry pump and the casing to complete the cleaning of the pile hole.

[0089] The device also includes:

[0090] The second hole cleaning module specifically comprises:

[0091] The slurry pumping unit is used to pump the slurry in the pile hole to the slurry pool through a conduit arranged in the steel cage and a slurry pump connected to the conduit;

[0092] The measurement module is used to obtain the depth of the current pile hole by lowering the measuring rope method. When the depth of the current pile hole is less than the designed pile hole depth, the grouting unit is used to pump grout again until the depth of the current pile hole is greater than the designed pile hole depth.

[0093] The end of the steel cage close to the ground is flush with the ground; and a plurality of grouting holes are arranged on a preset length of the end of the grouting pipe away from the ground.

[0094] The present invention arranges a plurality of grouting pipes in a steel cage, and after a preset time interval from the completion time of the last grouting, a preset amount of cement slurry in a cement mortar pool is input into each grouting pipe through a grouting pump by means of a grouting pipe, the number of grouting times is increased by 1, until the number of grouting times is equal to the preset number of grouting times, and the last grouting of the grouting pipe is performed, and in the process of the last grouting, the cement slurry in the cement mortar pool is input into each grouting pipe by means of a grouting pump by means of a grouting pipe, until the cement slurry seeps out of the ground, wherein the preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting, which is completely different from the traditional grouting technology, and the present invention completely avoids the uninterrupted one-time grouting of the grouting pipe in the traditional grouting technology (the grouting pressure is relatively large), and the grouting is terminated when the grouting amount reaches the design requirement, and the cement slurry at the bottom of the pile is easily diffused and cannot form an effective whole with the pile head (causing the pile foundation bearing capacity to be inconsistent with the design), and it is very likely to cause the cement slurry to flow to the bottoms of other piles, resulting in the problem that the grouting amount of other piles cannot meet the requirements.

[0095] Embodiment 3

[0096] like Figure 5 As shown, this embodiment also proposes a grouting method for bored piles in sandy soil layers, which uses a grouting device to inject a preset proportion of cement slurry into the bottom of the bored pile several times, so that the cement slurry penetrates into the sandy and gravel layer around the pile head of the bored pile; the grouting device includes a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence; the method includes the steps of:

[0097] S1: The drilling rig is in place and drilling is performed to form a pile hole;

[0098] S2: A steel cage is placed in the pile hole, and a plurality of grouting pipes are arranged on the steel cage. The grouting pipes are arranged perpendicular to the ground along the length direction of the steel cage and are fixedly connected to the steel cage; one end of the grouting pipe close to the ground is higher than the ground by a preset length, and the other end away from the ground goes down to the bottom of the pile hole and is longer than the preset length of the steel cage; the end of the grouting pipe away from the ground is bent (the grouting pipe includes a main body and a bent end, the bent end is the end of the grouting pipe away from the ground, and the main body of the grouting pipe is arranged vertically along the length direction of the steel cage), the bending length can be preset, which is 40 cm in this embodiment, and the bending degree is 30-45 degrees, and it is bent toward the center of the bottom of the pile hole, see for details Figure 5 .

[0099] S3: pouring concrete into the steel cage to form bored cast-in-place piles;

[0100] S4: within the first preset period after pouring concrete, flush each grouting pipe with clean water of preset pressure by a high-pressure pump to complete the unplugging of the grouting pipe;

[0101] S5: After the plugging is completed and within the second preset time period after the concrete is poured, a preset amount of cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump through a grouting pipe to complete the first grouting of the grouting pipe, and the number of grouting times is increased by 1; it is determined whether the number of grouting times is equal to the preset number of grouting times, if so, the process proceeds to step S7, if not, the process proceeds to step S6;

[0102] S6: After a preset time interval from the moment when the last grouting of the grouting pipe is completed, a preset amount of cement slurry in the cement mortar pool is again input into each grouting pipe through a grouting pump through a grouting pipe to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1;

[0103] S7: Determine whether the number of grouting times is equal to the preset number of grouting times. If not, repeat step S6. If so, enter the last grouting of the grouting pipe. The method of the last grouting is specifically as follows: starting from the completion time of the last grouting, after a preset time interval, the cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump using a grouting pipe until the cement slurry seeps out of the ground. The preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting.

[0104] In this embodiment, by bending the end of the grouting pipe, the cement slurry can penetrate deeper into the sand and egg layer.

[0105] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0106] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0107] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0108] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A grouting method for bored piles in sandy gravel soil, characterized in that: The method uses grouting equipment to inject cement slurry of a preset proportion into the bottom of a bored pile for multiple times, so that the cement slurry penetrates into the sand and egg layer around the pile head of the bored pile; the grouting equipment includes a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence; the method includes the steps of: S1: The drilling rig is in place and drilling is performed to form a pile hole; S2: placing a steel cage in the pile hole, the steel cage being provided with a plurality of grouting pipes, the grouting pipes being arranged perpendicular to the ground along the length direction of the steel cage and being fixedly connected to the steel cage; the end of the grouting pipe close to the ground is higher than the ground by a preset length, the end away from the ground is down to the bottom of the pile hole and is longer than the preset length of the steel cage; between step S2 and step S3, the pile hole is also cleaned, specifically: S21: pumping the slurry in the pile hole to the slurry pool through a conduit arranged in the steel cage and a slurry pump connected to the conduit; S22: obtaining the depth of the current pile hole by lowering the measuring rope method. When the depth of the current pile hole is less than the designed pile hole depth, pumping grout is performed again through step S21 until the depth of the current pile hole is greater than the designed pile hole depth; S3: pouring concrete into the steel cage to form bored cast-in-place piles; S4: within the first preset period after pouring concrete, flush each grouting pipe with clean water of preset pressure by a high-pressure pump to complete the unplugging of the grouting pipe; S5: After the plugging is completed and within the second preset time period after the concrete is poured, a preset amount of cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump through a grouting pipe to complete the first grouting of the grouting pipe, and the number of grouting times is increased by 1; it is determined whether the number of grouting times is equal to the preset number of grouting times, if so, the process proceeds to step S7, if not, the process proceeds to step S6; S6: After a preset time interval from the moment when the last grouting of the grouting pipe is completed, a preset amount of cement slurry in the cement mortar pool is again input into each grouting pipe through a grouting pump through a grouting pipe to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1; S7: Determine whether the number of grouting times is equal to the preset number of grouting times. If not, repeat step S6. If so, enter the last grouting of the grouting pipe. The method of the last grouting is specifically as follows: starting from the completion time of the last grouting, after a preset time interval, the cement slurry in the cement mortar pool is input into each grouting pipe through a grouting pump using a grouting pipe until the cement slurry seeps out of the ground. The preset time interval is less than the initial setting time of the cement slurry corresponding to the last grouting.

2. A grouting method for bored piles in sandy gravel soil according to claim 1, characterized in that: The step S1 also includes: Digging a hole at a predetermined pile position to place a casing above the ground, wherein the length of the casing is less than the length of the steel cage and the diameter of the casing is greater than the designed pile diameter of the bored pile; filling the gap between the outer wall of the casing and the hole wall, and compacting in layers; The step S1 specifically includes: the drilling machine is positioned and drilling is performed according to the positioning of the casing to form a pile hole; In the step S2, the steel cage is placed in the casing; The step between step S1 and step S2 also includes: cleaning the pile hole, specifically: S11: The sediment in the pile hole is extracted by a grout pump and casing to complete the cleaning of the pile hole.

3. A grouting method for bored piles in sandy gravel soil according to claim 1 or 2, characterized in that: The end of the steel cage close to the ground is higher than the ground; and a plurality of grouting holes are arranged on a preset length of the end of the grouting pipe away from the ground.

4. A grouting device for bored piles in sandy and gravel soil layers, characterized in that: The method uses a grouting device to inject cement slurry of a preset proportion into the bottom of a bored pile for multiple times, so that the cement slurry penetrates into the sand and egg layer around the pile head of the bored pile; the grouting device includes a grouting pipe, a grouting pipe, a grouting pump and a cement mortar pool connected in sequence; the device includes: A drilling module, used for drilling holes to form pile holes; A steel cage placement module is used to place the steel cage in the pile hole. The steel cage is provided with a plurality of grouting pipes, which are arranged perpendicular to the ground along the length direction of the steel cage and are fixedly connected to the steel cage; one end of the grouting pipe close to the ground is higher than the ground by a preset length, and the other end away from the ground is down to the bottom of the pile hole and is longer than the preset length of the steel cage; A pouring module, used to pour concrete into the steel cage to form bored cast-in-place piles; The unplugging module is used to flush each grouting pipe with clean water of preset pressure by a high-pressure pump within the first preset period after pouring concrete, so as to complete the unplugging of the grouting pipe; The initial grouting module is used to, after the plugging is completed and within the second preset period after the concrete is poured, use the grouting pump to input the preset amount of cement slurry in the cement mortar pool into each grouting pipe through the grouting pipe to complete the first grouting of the grouting pipe, and the number of grouting times is increased by 1; when the number of grouting times is equal to the preset number of grouting times, the last grouting is performed through the grouting completion module; when the number of grouting times is not equal to the preset number of grouting times, the next grouting is performed through the grouting module; The grouting module is used to, after a preset time interval from the completion time of the last grouting of the grouting pipe, input a preset amount of cement slurry in the cement mortar pool into each grouting pipe again through the grouting pipe through the grouting pump to complete the next grouting of each grouting pipe, and the number of grouting times is increased by 1; The grouting completion module is used to enter the last grouting of the grouting pipe when the number of grouting is equal to the preset number of grouting; when the number of grouting is not equal to the preset number of grouting, the next grouting is performed through the grouting module; the last grouting is specifically: from the completion time of the last grouting, after the preset time interval, the cement slurry in the cement mortar pool is input into each grouting pipe through the grouting pump through the grouting pipe until the cement slurry seeps out of the ground; the preset time interval is less than the initial setting time of the corresponding cement slurry during the last grouting; The device also includes: The second hole cleaning module specifically comprises: The slurry pumping unit is used to pump the slurry in the pile hole to the slurry pool through a conduit arranged in the steel cage and a slurry pump connected to the conduit; The measurement module is used to obtain the depth of the current pile hole by lowering the measuring rope method. When the depth of the current pile hole is less than the designed pile hole depth, the grouting unit is used to pump grout again until the depth of the current pile hole is greater than the designed pile hole depth.

5. A grouting device for bored piles in sandy gravel soil according to claim 4, characterized in that: The drilling process also includes: Digging a hole at a predetermined pile position to place a casing above the ground, wherein the length of the casing is less than the length of the steel cage and the diameter of the casing is greater than the designed pile diameter of the bored pile; filling the gap between the outer wall of the casing and the hole wall, and compacting in layers; The drilling module is specifically used to drill holes according to the positioning of the casing to form pile holes; In the reinforcement cage placement module, the reinforcement cage is placed in the casing; The device also includes: The first hole cleaning module is used to extract the sediment in the pile hole through the slurry pump and the casing to complete the cleaning of the pile hole.

6. A grouting device for bored piles in sandy gravel soil according to any one of claims 4 or 5, characterized in that: The end of the steel cage close to the ground is higher than the ground; and a plurality of grouting holes are arranged on a preset length of the end of the grouting pipe away from the ground.

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