Static pressure grouting pipe device for pile end of steel pipe pile and using method thereof

Abstract

This invention discloses a static pressure grouting pipe device and its usage method for steel pipe piles. The device uses static pressure to press the movable core tube grouting device into the required depth within the vertical projection range of the steel pipe pile wall. The movable core tube grouting device includes a grouting core tube and a protective sleeve. The side wall of the grouting core tube has a grouting port, and the lower end has a conical guide head. The connection point between the conical guide head and the lower end of the protective sleeve forms a seal. A matching limiting structure is provided between the upper end of the grouting core tube and the lower end of the protective sleeve to prevent the protective sleeve from detaching from the upper end of the grouting core tube. In use, the protective sleeve is pulled up to fully expose the grouting core tube for grouting. After completing grouting to the current depth, the movable core tube grouting device is pulled up again above the completed grouting depth, and this process is repeated until all grouting is completed. This invention enables the reuse of the grouting pipe material and allows for multiple grouting at any depth.

Description

Technical Field

[0001] This invention relates to the field of pile foundation construction technology, and in particular to a static pressure grouting pipe device for the pile tip of steel pipe piles and its usage method. Background Technology

[0002] According to the "Design Code for Highway Bridge and Culvert Foundations" (JTG 3363-2019), when the pile diameter is greater than or equal to 1.2m, the maximum soil plugging effect coefficient at the pile tip of conventional hammer-driven or static pressure-driven open steel pipe piles is 0.4, which is a larger reduction compared to closed steel pipe piles.

[0003] Meanwhile, in recent years, vibratory pile driving technology and equipment have been gradually applied in various projects. Vibratory pile driving technology, also known as high-frequency hydraulic non-resonance pile driving method, uses high-frequency vibration to create strong disturbance to the soil around the pile, destroying the soil structure, and combined with pile head driving equipment, i.e. counterweight, to drive the pile to the design elevation.

[0004] The high-frequency hydraulic non-resonance pile driving method has the following advantages: rapid construction (a 20m long pile in cohesive soil can be driven in less than 5 minutes), low noise, and minimal environmental impact. Currently, this method has been applied to some extent in bridge pile foundation projects in Shanghai, such as the Jia-Min Elevated Road, the Bei-Hong Interchange, the Yanjiang Tunnel River-Crossing Project, and the Jiyang Road Expressway.

[0005] However, vibratory driving of steel pipe piles causes significant disturbance to the soil around and at the pile tip, resulting in a long recovery time for the soil around and at the pile tip. Furthermore, the bearing capacity of the steel pipe pile after recovery is less than that of steel pipe piles driven by the driving method. The soil plugging effect of vibratory driving of steel pipe piles is not ideal and differs significantly from that of conventional hammer driving or static pressure driving of steel pipe piles. According to the "Design Specification for Highway Bridge and Culvert Foundations" (JTG 3363-2019), the design parameters for cohesive soil layers need to consider the reduction of vibration effects.

[0006] The aforementioned problems have affected the promotion and application of steel pipe piles, and it is necessary to take necessary technical measures to improve the bearing capacity of steel pipe piles.

[0007] In existing technologies, post-grouting at the pile end is an effective measure to solve the soil plugging effect of steel pipe piles. However, current post-grouting methods mainly involve fixing the grouting pipe to the steel pipe pile, which is costly and can only meet one grouting depth at each location, limiting the grouting impact range. Furthermore, pre-embedded grouting pipes present difficulties in protecting the grouting head, often resulting in problems with the inability to properly open the grouting port.

[0008] Therefore, how to solve the above-mentioned problems in the existing technology has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] In view of the above-mentioned deficiencies of the prior art, the present invention provides a static pressure grouting pipe device and a method for using steel pipe piles. The purpose is to realize the reuse of grouting pipe materials and to achieve multiple grouting at any depth, so as to achieve the injection of cement grout covering more areas, better improve the soil plugging effect at the pile end, and improve the bearing capacity of the pile end.

[0010] To achieve the above objectives, the present invention discloses a static pressure grouting pipe device for steel pipe piles, including a movable core tube grouting device, a static pressure penetrating device or an anchor rod static pressure device, and a static pressure penetrating test probe.

[0011] The lower end of the static cone penetration test probe is equipped with the movable core tube grouting device, which is pressed into the required depth within the vertical projection range of the steel pipe pile wall by static pressure.

[0012] The flexible core tube grouting device includes a grouting flower tube core tube and a protective sleeve sleeved outside the grouting flower tube core tube, which can move relative to the grouting flower tube core tube along its length direction;

[0013] The grouting flower tube core has a grouting port on its side wall and a tapered guide head at its lower end. When the tapered guide head is connected to the lower end of the protective sleeve, a seal is formed between the tapered guide head and the lower end of the protective sleeve.

[0014] A matching limiting structure is provided between the upper end of the grouting core tube and the lower end of the protective sleeve to prevent the lower end of the protective sleeve from detaching from the upper end of the grouting core tube.

[0015] Preferably, both the grouting core tube and the protective sleeve are made of steel pipe and have a length of not less than 0.5m;

[0016] The static cone penetration test probe is made of steel pipe, with a single length of 1m to 2m.

[0017] The protective sleeve and the static cone penetration test probe are sealed with PTFE tape.

[0018] Preferably, the position where the grouting core tube connects to the tapered guide head is provided with a sealing ring that matches the lower end of the protective sleeve.

[0019] Preferably, the limiting structure includes matching outer flanges disposed at the upper ends of the grouting pipe core tube, and an inwardly extending anti-reverse shoulder disposed at the lower end of the protective sleeve.

[0020] Preferably, the protective sleeve has the same outer diameter as the static cone penetration test probe and is directly connected to the static cone penetration test probe.

[0021] More preferably, the outer diameter of both the protective sleeve and the static cone penetration test probe is 42 mm;

[0022] The diameter of the core tube of the grouting flower pipe is 25mm.

[0023] Preferably, the outer diameter of the protective sleeve is larger than the outer diameter of the static cone penetration test probe.

[0024] A static penetration test protective tube is provided between the protective sleeve and the static penetration test probe rod;

[0025] The static cone penetration test tube has a structure in which the lower outer diameter is larger than the upper outer diameter. The lower outer diameter is the same as the outer diameter of the protective sleeve, and the upper outer diameter is the same as the outer diameter of the static cone penetration test probe.

[0026] The sum of the length of the lower part of the static penetration test tube and the length of the protective sleeve shall not be less than 3m.

[0027] More preferably, the outer diameter of the protective sleeve is 63.5 mm;

[0028] The outer diameter of both the grouting core tube and the static cone penetration test probe is 42 mm.

[0029] The present invention also provides a method for using a static pressure grouting pipe device at the pile end of a steel pipe pile, comprising the following steps:

[0030] Step 1: Drive the steel pipe piles that need to be grouted to the designed depth;

[0031] Step 2: Set one or more location points at the center or inside of the steel pipe pile as needed. After the steel pipe pile is in place, at each location point, use a static cone penetration test device or an anchor rod static pressure device to press the movable core tube grouting device and the static cone penetration test probe into the position 0.5m ± 5% below the bottom of the steel pipe pile.

[0032] Step 3: Using the static cone penetration test equipment or the anchor bolt static pressure equipment, pull up the protective sleeve of the movable core tube grouting device to the lower end of the protective sleeve and move it to the upper end of the grouting flower tube core tube, so that the grouting flower tube core tube is fully exposed.

[0033] Step 4: Connect the static cone penetration test probe to the grouting equipment through the grouting hose, and begin grouting at the pile end;

[0034] Step 5: After completing the grouting at the current depth, use the static cone penetration test equipment or the anchor bolt static pressure equipment to pull up the movable core tube grouting device above the completed grouting depth, and repeat steps 4 and 5 until all grouting is completed.

[0035] Step 6: After grouting to all depths is completed, the movable core tube grouting device and the static cone penetration test probe are pulled out using the static cone penetration test equipment or the anchor bolt static cone test equipment and then retrieved.

[0036] Preferably, in step 4, a reasonable grouting pressure and grouting volume are used during grouting;

[0037] If multiple grouting operations are performed, the interval between each two grouting operations should be less than the initial setting time of the cement grout.

[0038] If there are two or more of the aforementioned locations, and grouting needs to be started on two or more sets of the aforementioned flexible core tube grouting devices, then all the aforementioned flexible core tube grouting devices need to be grouted simultaneously, or the time interval between the latest grouting device and the earliest grouting device should be less than the initial setting time of the cement grout.

[0039] After each grouting is completed in step 5, the grouting valves of all the grouting hoses should be closed before the movable core tube grouting device is pulled out. The grouting valves should be opened again when grouting is required again.

[0040] The beneficial effects of this invention are:

[0041] This invention enables the reuse of grouting pipes, achieving the goals of environmental protection and reduced investment; it allows for multiple grouting at any depth, ensuring that the injected cement grout covers a wider area, thus improving the soil plugging effect at the pile end and increasing the bearing capacity of the pile end; the grouting device consists of a flexible core tube grouting and a protective sleeve, effectively protecting the grouting port and overcoming the problem of conventional grouting heads easily failing, and the grouting device is completely independent of the steel pipe pile, so it will not damage the pile structure.

[0042] This invention overcomes the shortcomings of existing technologies, such as high cost, single-depth grouting, and easy failure of grouting heads. It forms a complete and innovative new process for pile foundation grouting, successfully solves the problem of poor soil plugging effect at the pile end of steel pipe piles, improves the bearing capacity of steel pipe piles, and makes the post-grouting operation at the pile end of steel pipe piles more convenient, efficient, cost-effective, and reliable in terms of construction quality.

[0043] This invention makes post-grouting at the pile end of steel pipe piles more convenient, efficient, cost-effective, and reliable in terms of construction quality.

[0044] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0045] Figure 1 A schematic diagram of the structure of the grouting device for the flexible core tube in one embodiment of the present invention is shown.

[0046] Figure 2 This diagram illustrates the structure of the protective sleeve when it is moved to the point where the core tube of the grouting pipe is fully exposed, according to one embodiment of the present invention.

[0047] Figure 3 This diagram illustrates the structure of an embodiment of the present invention, showing the required depth to which the grouting device for the flexible core tube is pressed into the vertical projection range of the steel pipe pile wall.

[0048] Figure 4 This diagram illustrates the structure of the protective sleeve being lifted to fully expose the core tube of the grouting pipe in one embodiment of the present invention.

[0049] Figure 5 This diagram shows a structural view of a grouting device for a flexible core tube being raised to another depth for grouting in one embodiment of the present invention. Detailed Implementation

[0050] Example

[0051] like Figures 1 to 5 As shown, the static pressure grouting pipe device at the pile end of the steel pipe pile includes a movable core tube grouting device, a static pressure penetrating device or an anchor rod static pressure device, and a static pressure penetrating test probe 9.

[0052] Among them, the lower end of the static cone penetration test probe 9 is equipped with a movable core tube grouting device, which is pressed into the required depth within the vertical projection range of the pipe wall of the steel pipe pile 7 by static pressure.

[0053] The flexible core tube grouting device includes a grouting perforated core tube 1 and a protective sleeve 2 that is sleeved outside the grouting perforated core tube 1 and can move relative to it along the length of the grouting perforated core tube 1.

[0054] The side wall of the grouting flower tube core tube 1 is provided with a grouting port, and the lower end is provided with a tapered guide head 3. When the position of the tapered guide head 3 is connected to the lower end of the protective sleeve 2, a seal is formed with the lower end of the protective sleeve 2.

[0055] A matching limiting structure is provided between the upper end of the grouting core tube 1 and the lower end of the protective sleeve 2 to prevent the lower end of the protective sleeve 2 from detaching from the upper end of the grouting core tube 1.

[0056] The present invention provides a grouting port in the grouting core tube 1 of the grouting tube grouting device and uses a protective sleeve 2 for protection, which can effectively protect the grout outlet; it can realize multiple grouting at any depth and can improve the soil plugging effect at the pile end;

[0057] When the lower end of the grouting core tube 1 is connected to the tapered guide head 3 and is sleeved with the lower end of the protective sleeve 2, a seal is formed with the lower end of the protective sleeve 2. This structure enables the grouting device with movable core tube to achieve a sealing purpose when it is pressed in, ensuring that the adjacent cement slurry will not enter the grouting core tube 1.

[0058] Static cone penetration testing equipment and anchor bolt static pressure testing equipment are conventional devices for engineering surveys and foundation reinforcement, respectively.

[0059] This invention employs a static cone penetration test device to statically press the grouting device into the movable core tube and the static cone penetration test probe 9. After grouting is completed, the movable core tube grouting device and the static cone penetration test probe 9 can be pulled out for recycling, realizing the reusability of the grouting pipe material. Moreover, it forms a complete and innovative new process for pile foundation grouting, successfully solving the problem of poor soil plugging effect at the pile end of steel pipe pile 7 and improving the bearing capacity of steel pipe pile.

[0060] In some embodiments, both the grouting core tube 1 and the protective sleeve 2 are made of steel pipe and have a length of not less than 0.5m;

[0061] The static cone penetration test probe 9 is made of steel pipe, with a single length of 1m to 2m;

[0062] The protective sleeve 2 and the static cone penetration test probe 9 are sealed with PTFE tape.

[0063] In some embodiments, a sealing ring 4 matching the lower end of the protective sleeve 2 is provided at the connection position between the grouting core tube 1 and the tapered guide head 3.

[0064] In some embodiments, the limiting structure includes an outer flange 5 that matches each other and is respectively disposed at the upper end of the grouting flower core tube 1, and an inwardly extending anti-reverse shoulder 6 disposed at the lower end of the protective sleeve 2.

[0065] In practical applications, to facilitate the versatility of the grouting device with static cone penetration testing equipment or anchor bolt static pressure equipment, the outer diameter of the protective sleeve can be the same as that of the static cone penetration test protective sleeve, with an outer diameter of 63.5 mm and an inner core tube diameter of 42 mm. Alternatively, it can be the same as that of the static cone penetration test probe 9, i.e., an outer diameter of 42 mm and an inner core tube diameter of 25 mm. Details are as follows:

[0066] In some embodiments, the protective sleeve 2 has the same outer diameter as the static cone penetration test probe 9 and is directly connected to the static cone penetration test probe 9.

[0067] In some embodiments, the outer diameter of both the protective sleeve 2 and the static cone penetration test probe 9 is 42 mm;

[0068] The diameter of the core tube 1 of the grouting flower pipe is 25mm.

[0069] In some embodiments, the outer diameter of the protective sleeve 2 is larger than the outer diameter of the static cone penetration test probe 9;

[0070] A static penetration test protective tube is provided between the protective sleeve 2 and the static penetration test probe 9;

[0071] The static cone penetration test casing has a structure where the lower outer diameter is larger than the upper outer diameter. The lower outer diameter is the same as the outer diameter of the protective casing 2, and the upper outer diameter is the same as the outer diameter of the static cone penetration test probe 9.

[0072] The sum of the length of the lower part of the static cone penetration test casing and the length of the protective sleeve 2 shall not be less than 3m.

[0073] In practical applications, when the outer diameter of the protective sleeve 2 is larger than the outer diameter of the static penetration test probe 9, during the process of pressing the movable core tube grouting device into the required depth by static pressure, there will be an excessively large gap between the hole generated by the grouting device and the outer wall of the static penetration test probe 9. As a result, during grouting, the grout can easily escape upward from the gap, leading to some adverse effects. Therefore, a static penetration test protective sleeve is installed between the protective sleeve 2 and the static penetration test probe 9 to prevent the grout from escaping upward from the gap.

[0074] In some embodiments, the outer diameter of the protective sleeve 2 is 63.5 mm;

[0075] The outer diameter of both the grouting core tube 1 and the static cone penetration test probe 9 is 42 mm.

[0076] like Figures 3 to 5 As shown, the present invention also provides a method for using the static pressure grouting pipe device at the pile end of a steel pipe pile, comprising the following steps:

[0077] Step 1: Drive the steel pipe pile 7, which requires grouting, to the designed depth;

[0078] Step 2: Set one or more locations at the center or inside of the steel pipe pile 7 as needed. After the steel pipe pile 7 is in place, at each location, use a static cone penetration test device or an anchor rod static pressure device to press the movable core tube grouting device and the static cone penetration test probe 9 into the position 0.5m ± 5% below the bottom of the steel pipe pile 7.

[0079] Step 3: Use a static cone penetration test or anchor bolt static pressure device to pull up the protective sleeve 2 of the grouting device to the lower end of the protective sleeve 2 and move it to the upper end of the grouting core tube 1 so that the grouting core tube 1 is fully exposed.

[0080] Step 4: Connect the static cone penetration test probe 9 to the grouting equipment through the grouting hose 8, and begin post-grouting at the pile end;

[0081] Step 5: After completing the grouting at the current depth, use a static cone penetration test or anchor bolt static pressure test to pull up the grouting device above the completed grouting depth, and repeat steps 4 and 5 until all grouting is completed.

[0082] Step 6: After completing grouting at all depths, use a static cone penetration test device or an anchor bolt static pressure device to pull out the grouting device and the static cone penetration test probe 9, and then retrieve them.

[0083] During use, by grouting sequentially at various depths from bottom to top, and then using static cone penetration testing equipment or anchor bolt static pressure equipment to pull up to a certain depth after completing grouting at any depth, the grouting effect at the pile end can be improved, and the soil-locking effect of the steel pipe pile can be enhanced.

[0084] In some embodiments, in step 4, a reasonable grouting pressure and grouting volume are used during grouting;

[0085] If multiple grouting operations are performed, the interval between each two grouting operations should be less than the initial setting time of the cement grout.

[0086] If there are two or more locations where grouting needs to be started on two or more sets of movable core tube grouting devices, then all movable core tube grouting devices must be grouted simultaneously, or the time interval between the movable core tube grouting device that starts grouting last and the movable core tube grouting device that starts grouting earliest should be less than the initial setting time of the cement grout.

[0087] After completing each grouting in step 5, all grouting valves of the grouting hoses 8 should be closed before pulling out the grouting device. The grouting valves should be opened again when grouting is required again.

[0088] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method of using a pile tip static pressure grouting pipe device of a steel pipe pile, comprising a flexible core pipe grouting device, a static sounding static pressure equipment or an anchor rod static pressure equipment and a static sounding test probe rod (9); characterized in that, The lower end of the static sounding test probe rod (9) is provided with the adjustable core pipe grouting device, which is pressed into the steel pipe pile (7) by static pressure to the required depth within the vertical projection range of the pipe wall; The adjustable core pipe grouting device comprises a grouting flower pipe core pipe (1) and a protective sleeve (2) sleeved outside the grouting flower pipe core pipe (1) and capable of moving relatively along the length direction of the grouting flower pipe core pipe (1); The side wall of the grouting flower pipe core pipe (1) is provided with a grouting port, and the lower end is provided with a conical guide head (3); the position connected with the conical guide head (3) forms a seal with the lower end of the protective sleeve (2) when the lower end of the protective sleeve (2) is sleeved together. A matching limiting structure is arranged between the upper end of the grouting flower pipe core pipe (1) and the lower end of the protective sleeve (2) to prevent the lower end of the protective sleeve (2) from being separated from the upper end of the grouting flower pipe core pipe (1). The use steps are as follows: Step 1, sink the steel pipe pile (7) needing grouting to the designed depth; Step 2, according to the need, set more than one position point in the vertical projection range of the pipe wall of the steel pipe pile (7), and after the steel pipe pile (7) is in place, press the adjustable core pipe grouting device and the static sounding test probe rod (9) into the position 0.5m±5% below the pile bottom of the steel pipe pile (7) at each position point by using the static sounding static pressure equipment or the anchor rod static pressure equipment; Step 3, pull up the protective sleeve (2) of the adjustable core pipe grouting device to the position that the lower end of the protective sleeve (2) moves to the upper end of the grouting flower pipe core pipe (1) by using the static sounding static pressure equipment or the anchor rod static pressure equipment, so that the grouting flower pipe core pipe (1) is completely exposed; Step 4, connect the static sounding test probe rod (9) with the grouting equipment through the grouting hose (8) to start the post-grouting of the pile end; Step 5, after the grouting at the current depth is completed, pull up the adjustable core pipe grouting device to the position above the depth at which the grouting is completed by using the static sounding static pressure equipment or the anchor rod static pressure equipment, and repeat steps 4 and 5 until all the grouting is completed; Step 6, after the grouting at all depths is completed, pull up the adjustable core pipe grouting device and the static sounding test probe rod (9) by using the static sounding static pressure equipment or the anchor rod static pressure equipment, and recycle.

2. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 1, characterized in that, The grouting flower pipe core pipe (1) and the protective sleeve (2) are both made of steel pipe material, and the length is not less than 0.5m; The static sounding test probe rod (9) is made of steel pipe material, and the length of a single rod is 1m to 2m; The protective sleeve (2) and the static sounding test probe rod (9) are sealed by raw material belts.

3. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 1, characterized in that, The position where the grouting flower pipe core pipe (1) is connected with the conical guide head (3) is provided with a sealing ring (4) matched with the lower end of the protective sleeve (2).

4. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 1, characterized in that, The limiting structure comprises an outer flange (5) matched with each other and arranged at the upper end of the grouting flower pipe core pipe (1), and an inwardly extending retreat-stop shoulder (6) arranged at the lower end of the protective sleeve (2).

5. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 1, characterized in that, The protective sleeve (2) is directly connected with the static sounding probe (9) and has the same outer diameter as the static sounding probe (9).

6. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 5, characterized in that, The protective sleeve (2) and the static sounding probe (9) both have an outer diameter of 42 mm. The diameter of the grouting flower tube core tube (1) is 25 mm.

7. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 1, characterized in that, The outer diameter of the protective sleeve (2) is greater than the outer diameter of the static sounding probe (9). A static sounding protective sleeve is arranged between the protective sleeve (2) and the static sounding probe (9). The static sounding protective sleeve has a structure in which the outer diameter of the lower part is greater than the outer diameter of the upper part, the outer diameter of the lower part is the same as the outer diameter of the protective sleeve (2), and the outer diameter of the upper part is the same as the outer diameter of the static sounding probe (9). The length of the lower part of the static sounding protective sleeve and the length of the protective sleeve (2) are not less than 3 m.

8. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 7, characterized in that, The outer diameter of the protective sleeve (2) is 63.5 mm. The outer diameter of the grouting flower tube core tube (1) and the static sounding probe (9) is 42 mm.

9. The method of using a pile tip static pressure grouting pipe device of a steel pipe pile according to claim 1, characterized in that, In step 4, reasonable grouting pressure and grouting amount are adopted during grouting; If multiple grouting is performed, the interval between the opening time of each two grouting should be less than the initial setting time of the cement slurry; If there are more than two position points, and more than two sets of the active core tube grouting device need to be opened for grouting, all the active core tube grouting devices need to be grouted synchronously, or the time interval between the active core tube grouting device that is opened for grouting the latest and the active core tube grouting device that is opened for grouting the earliest should be less than the initial setting time of the cement slurry; After each grouting is completed in step 5, the grouting valve of all the grouting hoses (8) should be closed before the active core tube grouting device is pulled up, and the grouting valve should be opened again when grouting is needed again.

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