A device and construction method for pouring piles by blasting holes in calcareous sand

Abstract

The invention discloses a device and a construction method for pouring cast-in-place piles by blasting holes in calcareous sand, comprising a carbon dioxide fracturing device arranged in a borehole, an expandable sleeve arranged on the periphery of the carbon dioxide fracturing device, the expandable sleeve comprising a plurality of inner arc panels located on the inner side and a plurality of outer arc panels located on the outer side, both sides of each outer arc panel respectively slidingly cooperate with the side of an inner arc panel, and a steel cage is arranged on the inner side of the expandable sleeve after the hole is blasted; the invention greatly improves the compactness of the calcareous sand around the pile hole, effectively prevents the calcareous sand from collapsing, improves the stability and bearing capacity of the pile, and has broad engineering practice significance and application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of pile foundation construction suitable for calcareous sand or soft and loose geology, and in particular to a device and a construction method for pouring piles by blasting holes in calcareous sand. Background Art

[0002] With the rapid development of social economy, pile foundations are widely used in the construction of roads, ports, bridges and other projects. Pile foundations bear the load transmitted from the upper part through pile side friction and pile end resistance. How to cast cast-in-place piles that meet the standards in calcareous sand and loose and soft sandy soil is one of the important topics that researchers have long paid attention to.

[0003] The main reason for the collapse of calcareous sand around the pile hole is that after the pile hole is excavated, the calcareous sand itself is loose and not dense enough. Therefore, how to cast bored piles in loose and easily collapsed calcareous sand is one of the topics that current researchers have long paid attention to. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a device and construction method for pouring piles by blasting holes in calcareous sand, which can greatly increase the density of calcareous sand around the pile hole, prevent calcareous sand from collapsing, and improve the stability and bearing capacity of the piles.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a device for pouring cast-in-place piles by blasting holes in calcareous sand, comprising a carbon dioxide fracturing device arranged in a drilled hole, an expandable sleeve is arranged on the periphery of the carbon dioxide fracturing device, the expandable sleeve comprises a plurality of inner arc panels located on the inner side and a plurality of outer arc panels located on the outer side, both sides of each outer arc panel are respectively slidably matched with the side of an inner arc panel, and a steel cage is arranged on the inner side of the expandable sleeve after the hole is blasted.

[0006] Preferably, a sliding groove which slidably cooperates with the side of the inner arc panel is fixedly provided on the inner side of the outer arc panel.

[0007] Preferably, the slide groove is a U-shaped plate structure, which is fixedly connected to the inner side of the outer arc panel, and the side of the slide groove is provided with a through hole that cooperates with the inner arc panel.

[0008] Preferably, a clamping rod is fixedly provided on the side of the inner arc panel, a clamping hole is provided on the back of the slide groove, and the clamping rod cooperates with the clamping hole.

[0009] Preferably, a conical anti-drop hook is also provided at the end of the clamping rod.

[0010] Preferably, before blasting the hole, a large volume of aggregate is provided in the gap between the periphery of the expandable sleeve and the inner wall of the borehole.

[0011] Preferably, the bulk aggregate is crushed stone with a particle size of 40-80 mm.

[0012] In addition, the present invention also discloses a construction method for the above-mentioned device for blasting bored piles in calcareous sand, which comprises the following steps:

[0013] Step 1: After drilling a hole in the area where the calcareous sand is located, place the carbon dioxide fracturing device in the hole and fix it, then adjust the bottom of the expandable sleeve to align with the hole, sink the expandable sleeve so that its bottom is planted, and during the sinking process, hit the top of the expandable sleeve with a vibrating hammer to vibrate the expandable sleeve to achieve the sinking process;

[0014] Step 2: When the expandable sleeve is sunk to the designed height, check its height, verticality and center deviation;

[0015] Step 3: Add bulk aggregate to the gap between the outer periphery of the expandable sleeve and the inner wall of the drill hole;

[0016] Step 4: Select the amount of liquid carbon dioxide required for the carbon dioxide fracturing device according to the designed depth and diameter of the pile hole;

[0017] Step 5: Compress the liquid carbon dioxide into the blasting tube in the carbon dioxide fracturing device through a high-pressure pump;

[0018] Step 6: After the carbon dioxide fracturing device is activated, the liquid carbon dioxide in the blasting tube is instantly heated and vaporized. The impact force generated by the heating and vaporization produces an outward squeezing force on the expandable sleeve;

[0019] Step 7: The expandable sleeve expands outwards for a certain distance, squeezing the inner wall of the borehole, so that the calcareous sand on the surface of the inner wall of the borehole forms a crushing and compacting zone, and the large volume of aggregate is embedded inwardly into the calcareous sand;

[0020] Step 8: After the blasting process is completed, the carbon dioxide fracturing device is taken out from the expandable sleeve, and then the steel cage is lowered into the expandable sleeve. Then, while pouring the expansive concrete into the steel cage, the expandable sleeve is pulled upwards and vibrated with a vibrating rod. The entire pouring process is carried out in sections.

[0021] Preferably, when the expandable sleeve expands outwards for a certain distance in Step 7, relative sliding occurs between the outer arc panel and the inner arc panel until the clamping rod enters the clamping hole and stops sliding.

[0022] Beneficial effects of the present invention:

[0023] 1. During the blasting hole-forming process, the expandable sleeve of the present invention can evenly squeeze the calcareous sand on the inner wall of the borehole outward when expanding, so that the formed pile hole is not only dense, but also the density of each area is uniform, which reduces the process of protecting the inner wall of the pile hole, thereby saving materials and accelerating the construction progress.

[0024] 2. After use, the expandable sleeve of the present invention can be pulled out and reused. The expandable function can be restored by simply withdrawing the clamping rod from the clamping hole.

[0025] 3. The expandable sleeve in the present invention can be manufactured according to the diameter of the pile hole in the actual project, so that a corresponding number of outer arc panels and inner arc panels can be selected for combination, which makes the construction process more flexible.

[0026] 4. In the process of sinking the expandable sleeve into the borehole, part of the calcareous sand will be retained inside the expandable sleeve. The calcareous sand does not need to be dug out and can be used as a mixture for subsequent pouring of expansive concrete, thereby saving construction costs.

[0027] 5. When the expandable sleeve in the present invention expands outwards for a certain distance, the large-volume aggregate can be embedded inwards into the calcareous sand, which can increase the degree of bonding between the expansive concrete and the calcareous sand in subsequent processes, and can greatly improve the stability and bearing capacity of the pile; in addition, the friction between the expansive concrete and the inner wall of the pile hole can be increased, thereby increasing the friction of the pile body and further increasing the bearing capacity of the pile.

[0028] 6. The present invention utilizes carbon dioxide blasting, and there will be no duds, which greatly reduces the probability of casualties. Moreover, the carbon dioxide blasting is controllable throughout the entire process, and both the force and direction can be controlled. Therefore, it is more suitable for modern construction sites, making the construction process safer and more reliable.

[0029] 7. The present invention greatly improves the compactness of the calcareous sand around the pile hole, effectively prevents the calcareous sand from collapsing, improves the stability and bearing capacity of the pile, and has broad engineering practice significance and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the top view of a device for pouring piles by blasting holes in calcareous sand;

[0031] Figure 2 for Figure 1 A schematic diagram of the structure of the expandable sleeve from above;

[0032] Figure 3 for Figure 2 An enlarged structural diagram of the connection between the middle and outer arc panels, the inner arc panels and the slideway;

[0033] Figure 4 It is a schematic diagram of the arrangement structure of the device of the present invention in the drill hole before pouring;

[0034] Figure 5 Schematic diagram of the structure after the pile hole is poured. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0036] like Figures 1 to 5 As shown, a device for pouring cast-in-place piles by blasting holes in calcareous sand comprises a carbon dioxide fracturing device 2 arranged in a borehole 1, an expandable sleeve 3 is arranged on the periphery of the carbon dioxide fracturing device 2, the expandable sleeve 3 comprises a plurality of inner arc panels 3.1 located on the inner side and a plurality of outer arc panels 3.2 located on the outer side, both sides of each outer arc panel 3.2 are respectively slidably matched with the side of an inner arc panel 3.1, and a steel cage 4 is arranged on the inner side of the expandable sleeve 3 after the hole is blasted.

[0037] Preferably, a slide groove 3.3 is fixedly provided on the inner side of the outer arc panel 3.2 and is slidably matched with the side of the inner arc panel 3.1. Figure 1 and 2 As shown, by providing the slide groove 3.3, the relative sliding between the outer arc panel 3.2 and the inner arc panel 3.1 can be made smoother.

[0038] Preferably, the slide groove 3.3 is a U-shaped plate structure, which is fixedly connected to the inner side of the outer arc panel 3.2, and the side of the slide groove 3.3 is provided with a through hole that matches the inner arc panel 3.1. Figure 1 and 2 As shown, in this embodiment, the slide groove 3.3 not only plays a role in realizing the sliding connection between the outer arc panel 3.2 and the inner arc panel 3.1, but also plays a role in connecting support, that is, when the expandable sleeve 3 is vertically placed in the borehole 1, the outer arc panel 3.2 and the inner arc panel 3.1 of the expandable sleeve 3 will not separate from each other.

[0039] Preferably, a clamping rod 3.4 is fixedly provided on the side of the inner arc panel 3.1, and a clamping hole 3.5 is provided on the back of the slide slot 3.3, and the clamping rod 3.4 cooperates with the clamping hole 3.5. Figure 3As shown, after the outer arc panel 3.2 and the inner arc panel 3.1 slide relative to each other, the clamping rod 3.4 has two functions here. The first function is that the clamping rod 3.4 itself has a length. When the clamping rod 3.4 moves to the vicinity of the perforation position on the side of the slide groove 3.3, it can form a barrier to prevent the outer arc panel 3.2 and the inner arc panel 3.1 from separating due to expansion; the second function is that when the clamping rod 3.4 contacts the clamping hole 3.5, due to the action of the radial expansion force, the clamping rod 3.4 enters the clamping hole 3.5, so that the outer arc panel 3.2 and the inner arc panel 3.1 will not slide relative to each other, so that the expansion size is fixed. Usually, the location of the clamping hole 3.5 is close to the perforation position on the side of the slide groove 3.3. In this way, after the blasting is completed, the diameter size of the entire expandable sleeve 3 after expansion remains unchanged, the shaping is completed, and no shrinkage will occur, which is beneficial to the subsequent casting process.

[0040] Preferably, a conical anti-drop hook 3.6 is also provided at the end of the clamping rod 3.4. Figure 3 As shown, when the clamping rod 3.4 enters the clamping hole 3.5, the conical anti-dropping hook 3.6 has a large head and a small tail, so it is easy to enter the clamping hole 3.5, but it is not easy to withdraw from the clamping hole 3.5, thus playing a certain anti-dropping function.

[0041] Preferably, before blasting, a large-volume aggregate 5 is provided in the gap between the outer periphery of the expandable sleeve 3 and the inner wall of the borehole 1. After the large-volume aggregate 5 is provided, when the expandable sleeve 3 expands outwards by a certain distance, the large-volume aggregate 5 can be embedded inwards into the calcareous sand, which can increase the degree of bonding between the expansive concrete and the calcareous sand in the subsequent process, and can greatly improve the stability and bearing capacity of the pile. In addition, the friction between the expansive concrete and the inner wall of the borehole 1 can also be increased, thereby increasing the friction of the pile body, and thus increasing the bearing capacity of the pile.

[0042] Preferably, the bulk aggregate 5 is crushed stone with a particle size of 40-80 mm.

[0043] In addition, the present invention also discloses a construction method for the above-mentioned device for blasting bored piles in calcareous sand, which comprises the following steps:

[0044] Step 1: After drilling a hole in the area where the calcareous sand is located, place the carbon dioxide fracturing device 2 into the borehole 1 and fix it, then adjust the bottom of the expandable sleeve 3 to align with the borehole 1, sink the expandable sleeve 3 so that its bottom is planted, and during the sinking process, hit the top of the expandable sleeve 3 with a vibrating hammer to vibrate the expandable sleeve 3 to achieve the sinking process;

[0045] Step 2: When the expandable sleeve 3 is sunk to the designed height, check its height, verticality and center deviation;

[0046] Step 3: Add bulk aggregate 5 (such as Figure 4 shown);

[0047] Step 4: Select the amount of liquid carbon dioxide required by the carbon dioxide fracturing device 2 according to the design depth and hole diameter requirements of the pile hole;

[0048] Step 5: Compressing liquid carbon dioxide into the blasting tube in the carbon dioxide fracturing device 2 through a high-pressure pump;

[0049] Step 6: After the carbon dioxide fracturing device 2 is started, the liquid carbon dioxide in the blasting tube is instantly heated and vaporized. The impact force generated after heating and vaporization produces an outward squeezing force on the expandable sleeve 3;

[0050] Step 7: The expandable sleeve 3 expands outwards by a certain distance, squeezing the inner wall of the borehole 1, so that the calcareous sand on the inner wall surface of the borehole 1 forms a crushing and compacting zone, and the large-volume aggregate 5 is embedded inwards into the calcareous sand (such as Figure 5 shown);

[0051] Step 8: After the blasting process is completed, the carbon dioxide fracturing device 2 is taken out from the expandable sleeve 3, and then the steel cage 4 is lowered into the expandable sleeve 3. Then, while pouring the expansion concrete into the steel cage 4, the expandable sleeve 3 is pulled upward and vibrated with a vibrating rod. The entire pouring process is poured in sections (see after the pouring is completed). Figure 5 ).

[0052] Preferably, when the expandable sleeve 3 expands outwards for a certain distance in Step 7, relative sliding occurs between the outer arc panel 3.2 and the inner arc panel 3.1 until the clamping rod 3.4 enters the clamping hole 3.5 and stops sliding.

[0053] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A device for pouring piles by blasting holes in calcareous sand, comprising a carbon dioxide fracturing device (2) arranged in a borehole (1), characterized in that: An expandable sleeve (3) is disposed on the periphery of the carbon dioxide fracturing device (2), and the expandable sleeve (3) comprises a plurality of inner arc panels (3.1) located on the inner side and a plurality of outer arc panels (3.2) located on the outer side, and both sides of each outer arc panel (3.2) are respectively slidably matched with the side of an inner arc panel (3.1), and a steel cage (4) is disposed on the inner side of the expandable sleeve (3) after the hole is blasted; A sliding groove (3.3) is fixedly provided on the inner side of the outer arc panel (3.2) and is slidably matched with the side of the inner arc panel (3.1); The slide groove (3.3) is a U-shaped plate-like structure, which is fixedly connected to the inner side of the outer arc panel (3.2), and a through hole matching the inner arc panel (3.1) is provided on the side of the slide groove (3.3); A clamping rod (3.4) is also fixedly provided on the side of the inner arc panel (3.1), a clamping hole (3.5) is provided on the back of the slide groove (3.3), and the clamping rod (3.4) cooperates with the clamping hole (3.5); A conical anti-drop hook (3.6) is also provided at the end of the clamping rod (3.4).

2. A device for pouring piles by blasting holes in calcareous sand according to claim 1, characterized in that: Before blasting the hole, a large-volume aggregate (5) is provided in the gap between the outer periphery of the expandable sleeve (3) and the inner wall of the drill hole (1).

3. A device for pouring piles by blasting holes in calcareous sand according to claim 2, characterized in that: The bulk aggregate (5) is crushed stone with a particle size of 40-80 mm.

4. A construction method for a device for pouring piles by blasting holes in calcareous sand according to any one of claims 1 to 3, characterized in that: It includes the following steps: Step 1: After drilling a hole in the area where the calcareous sand is located, place the carbon dioxide fracturing device (2) into the borehole (1) and fix it, then adjust the bottom of the expandable sleeve (3) to align with the borehole (1), sink the expandable sleeve (3) so that its bottom is attached to the bed, and during the sinking process, hit the top of the expandable sleeve (3) with a vibrating hammer, thereby vibrating the expandable sleeve (3) to achieve the sinking process; Step 2: When the expandable sleeve (3) is sunk to the designed height, check its height, verticality and center offset; Step 3: Adding bulk aggregate (5) into the gap between the outer periphery of the expandable sleeve (3) and the inner wall of the drill hole (1); Step 4: Select the amount of liquid carbon dioxide required by the carbon dioxide fracturing device (2) according to the designed depth and diameter of the pile hole; Step 5: Compressing liquid carbon dioxide into a blasting tube in the carbon dioxide fracturing device (2) through a high-pressure pump; Step 6: After the carbon dioxide fracturing device (2) is activated, the liquid carbon dioxide in the blasting tube is instantly heated and vaporized, and the impact force generated by the heating and vaporization generates an outward squeezing force on the expandable sleeve (3); Step 7: The expandable sleeve (3) expands outwards by a certain distance, squeezing the inner wall of the borehole (1), so that the calcareous sand on the inner wall surface of the borehole (1) forms a crushing and compacting zone, and the large-volume aggregate (5) is embedded inwards into the calcareous sand; Step 8: After the blasting process is completed, the carbon dioxide fracturing device (2) is taken out from the expandable sleeve (3), and then the steel cage (4) is lowered into the expandable sleeve (3). Then, while pouring the expansion concrete into the steel cage (4), the expandable sleeve (3) is pulled upward and vibrated with a vibrating rod. The entire pouring process is performed in a segmented pouring manner.

5. The construction method of the device for pouring piles by blasting holes in calcareous sand according to claim 4, characterized in that: When the expandable sleeve (3) expands outwards a certain distance in Step 7, relative sliding occurs between the outer arc panel (3.2) and the inner arc panel (3.1) until the clamping rod (3.4) enters the clamping hole (3.5) and stops sliding.

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