A method for reinforcing the foundation of a building above an underground box culvert in a river embankment backfill area

Abstract

The application discloses a construction method for hammering a hole and expanding a head, and the construction method can not only avoid the influence of pipelines and box culverts on the ordinary foundation reinforcement, but also can make the construction speed faster, reduce the construction cost and shorten the construction period due to the easy ramming construction of the rammed expanded pile in the bearing layer and the short overall pile length.

Description

Technical Field

[0001] This invention relates to the field of foundation reinforcement technology, specifically a method for reinforcing the foundation of a building above an underground box culvert in a river embankment backfill area. Background Technology

[0002] In the development process of riverside cities, flood control and widening of river channels are often achieved by building river embankments. The widened areas are usually backfilled with miscellaneous fill, construction waste, and sand and gravel from the river channel, resulting in low overall foundation bearing capacity. In addition, riverside urban areas often include large old urban areas with complex underground pipelines.

[0003] Therefore, due to the low bearing capacity of the foundation surface and the presence of underground pipelines and culverts in this area, foundation replacement and raft foundations cannot be used, which makes foundation reinforcement construction difficult. To address this, we designed a foundation reinforcement method that applies rammed pile technology to this location.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is the closest prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reinforcing the foundation of buildings above underground box culverts in river embankment backfill areas, in order to solve the problem mentioned in the background art that the bearing capacity of the foundation surface in this area is low and there are underground pipelines and culverts, so it is impossible to use foundation replacement and raft foundation, which leads to difficulties in foundation reinforcement construction.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for reinforcing the foundation of a building above an underground box culvert in a riverbank backfill area, comprising the following steps:

[0007] S1: Measurement and positioning, measurement and setting out, and determination of pile positions using a total station;

[0008] S2: Hammering to form a hole, and then using a heavy hammer on a pile driver to drive the casing to the designed depth;

[0009] S3: After the casing is sunk to the design depth, the casing is lifted upwards a certain distance. The pipe plug inside the casing is moved up to above the filling port on the casing. Then, the filling material is introduced from the filling port, and the pipe plug is then tamped downwards to form the tamping and expanding head.

[0010] S4: Measure the three-blow penetration. After the tamping head has formed a dense state, without filling, let the hammer fall freely and hit the pipe plug, and measure the three-blow penetration.

[0011] S5: Rebar cage placement: The prefabricated rebar cages are hoisted one by one by a crane and then placed inside the casing;

[0012] S6: Concrete pouring: After the steel cage is placed, concrete is poured into the casing to form the main body of the foundation pile;

[0013] S7: Pipe pulling and pile forming. After the concrete is poured, the casing is pulled out.

[0014] Preferably, the pile position determination in step S1 should be performed three times: once before excavating and burying the casing, and once after burying the casing to ensure that the deviation between the center of the casing and the pile position is no more than 50mm, and the pile position is marked. Then, the elevation of the casing is measured with a level and the measurement record is made. The third measurement is performed after the pile foundation is in place, and it is checked whether the pile foundation is aligned with the pile center mark. In addition, the center point of the pile position is marked by the cross-stud method.

[0015] Preferably, in step S2, the casing should be kept perpendicular to the ground during tamping, which can be checked by using a plumb bob.

[0016] Preferably, in step S3, when the casing is lifted to one end, the diameter expansion device can be used to expand the diameter of the rammed head and form dense expansion holes.

[0017] Preferably, the rammed and expanded piles formed by the above steps are evenly distributed on both sides of the underground box culvert and kept at least 1 meter away from the underground box culvert to avoid affecting the underground box culvert.

[0018] Preferably, the diameter expanding device includes:

[0019] The expansion assembly is connected to the center of the tube plug via a connector;

[0020] An opening and closing door is located above the filling port of the casing and is used for placing and removing the expansion assembly inside the casing.

[0021] Preferably, the connector includes a sleeve rod disposed at the center of the plug and a sleeve connected to the sleeve rod.

[0022] Preferably, the diameter expanding component includes:

[0023] The connecting post is fixedly connected to the sleeve;

[0024] Multiple sets of expansion plates are arranged in an array around the connecting column, with the connecting column as the center. The multiple sets of expansion plates and the connecting group are connected by telescopic components.

[0025] Multiple sets of top columns are evenly distributed on the outer wall of the expansion plate.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention, through its construction method, not only avoids the difficulties in foundation reinforcement caused by the presence of pipelines, box culverts, etc., but also, because the rammed and expanded piles are easy to construct in the bearing layer and have a relatively short overall pile length, it can speed up construction, reduce construction costs, and shorten the construction period.

[0028] This invention, through the pretreatment setting of the diameter expansion device, enables the rammed head to form a larger radius and a closer contact with the soil surface when the pile length is short and the soil is relatively soft. As a result, the rammed pile is more stable after it is formed, and thus the foundation formed by the rammed pile is more solid. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the process of the present invention;

[0030] Figure 2 This is a perspective view of the expansion device of the present invention.

[0031] Figure 3 This is the interior of the diameter expansion device of the present invention.

[0032] Reference numerals: 1-Casing; 2-Pipe plug; 3-Expanding device; 31-Expanding assembly; 311-Connecting column; 312-Expanding plate; 313-Telescopic component; 314-Top column; 32-Opening and closing door; 33-Connecting component; 331-Sleeve rod; 332-Sleeve. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1-3 This invention provides a technical solution: a method for reinforcing the foundation of a building above an underground box culvert in a river embankment backfill area, comprising the following steps:

[0035] S1: Measurement and positioning, measurement and setting out, and determination of pile positions using a total station;

[0036] S2: Hammering to form a hole, and then using the heavy hammer on the pile driver to drive the casing 1 to the designed depth;

[0037] S3: After the casing 1 is sunk to the design depth, the casing 1 is lifted upwards a certain distance. The inner plug 2 of the casing 1 is moved upwards to above the filling port of the casing 1. Then, the filling material is introduced from the filling port, and the plug 2 is rammed downwards. The ramming head is formed by squeezing the filling material. The ramming head is formed at a certain distance when the casing 1 is lifted.

[0038] S4: Measure the three-blow penetration. After the tamping head has formed a dense state, without filling, let the hammer fall freely and hit the pipe plug 2. Measure the three-blow penetration. The penetration must meet the requirements. Each level of penetration should be smaller or equal to the previous blow, and the cumulative penetration value should meet the design requirements of no more than 10cm. If the design requirements are not met, filling should continue until the three-blow penetration requirements are met. The free fall distance of the hammer should be 6m.

[0039] S5: Rebar cage placement: The prefabricated rebar cages are hoisted one by one by a crane and placed inside the casing 1;

[0040] S6: Pour concrete. After the steel cage is placed, pour concrete into the casing 1 to form the main body of the foundation pile.

[0041] S7: Pipe pulling and pile forming. After the concrete is poured, the casing 1 is pulled out.

[0042] In step S1, the pile position should be determined three times. The first measurement should be taken before the casing 1 is excavated and buried. The second measurement should be taken after the casing 1 is buried to ensure that the deviation between the center of the casing 1 and the pile position is no more than 50mm and the pile position should be marked. Then, the elevation of the casing 1 should be measured with a level and the measurement record should be made. The third measurement should be taken after the pile foundation is in place and to check whether the pile foundation is aligned with the pile center mark. In addition, the center point of the pile position is marked by the cross-stud method.

[0043] In addition, in step S2, the casing 1 should be kept perpendicular to the ground during tamping, which can be checked by using a plumb bob.

[0044] Meanwhile, in step S3, when the casing 1 is lifted to one end, the diameter expansion device 3 can be used to expand the diameter at the point where the rammed head is formed, and form dense expansion holes, thereby increasing the size of the rammed head. This allows the rammed pile to improve its overall stability performance when the depth of the rammed pile is small due to the presence of underground culverts, by expanding the radius of the rammed head and making it more closely integrated with the compacted soil.

[0045] The rammed and expanded piles formed through the above steps are evenly distributed on both sides of the underground box culvert and kept at least 1 meter away from the underground box culvert to avoid affecting the underground box culvert.

[0046] In addition, the diameter expanding device 3 includes:

[0047] The expansion assembly 31 is connected to the center of the tube plug 2 via the connector 33;

[0048] The opening and closing door 32 is located above the filling port of the casing 1 and is used for placing and removing the diameter expansion assembly 31 inside the casing 1.

[0049] The connector 33 includes a sleeve 331 located at the center of the plug 2 and a sleeve 332 connected to the sleeve 331. The sleeve 332 is connected to the sleeve 331 by means of threads or snap-fit.

[0050] Finally, the diameter expansion assembly 31 includes:

[0051] The connecting post 311 is fixedly connected to the sleeve 332;

[0052] Multiple sets of expansion plates 312 are arranged in an array around the connecting column 311 with the connecting column 311 as the center. The multiple sets of expansion plates 312 and the connecting group are connected by telescopic members 313. The telescopic members 313 can be set as electric telescopic rods or cylinders.

[0053] Multiple sets of top columns 314 are evenly arranged on the outer wall of the expansion plate 312;

[0054] Before the filling and enlarging the hole, the enlarging component 31 is installed on the pipe plug 2 through the connector 33 from the opening and closing gate 32. Then, the pipe plug 2 is transported to the bottom of the casing 1 by the moving equipment on the pile driver, so that the enlarging component 31 is placed at the position where the hole needs to be enlarged by the distance of the lifting end of the casing 1. Then, the enlarging plate 312 is moved to extend and retract by the telescopic component 313. The extension and retraction of the enlarging plate 312 causes the soil hole surface of the enlarging plate 312 to impact, thereby increasing the radius at that point. At the same time, the setting of the top column 314 can form a hole during the impact. Thus, when the enlarged head is formed later, this pretreatment can make the enlarged head radius larger and the hole formed with the soil at that point can be more tightly and firmly combined after the filling is completed.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for reinforcing the foundation of a building above an underground box culvert in a riverbank backfill area, characterized in that... Includes the following steps: S1: Measurement and positioning, measurement and setting out, and determination of pile positions using a total station; S2: Hammering to form a hole, and then using the heavy hammer on the pile driver to ram the casing (1) to the designed depth; S3: Enlarged head construction, after sinking the casing (1) to the design depth, lift the casing (1) a certain distance, the inner pipe plug (2) of the casing (1) moves up to above the filling port of the casing (1), and then the filling material is input from the filling port, and then the pipe plug (2) is rammed downward to form the rammed head, which passes through; S4: Measure the three-blow penetration. After the ramming head forms a dense state, without filling, let the hammer fall freely and hit the pipe plug (2). Measure the three-blow penetration. S5: Rebar cage placement: The pre-made rebar cages are hoisted one by one by a crane and placed inside the casing (1); S6: Pour concrete. After the steel cage is placed, pour concrete into the casing (1) to form the main body of the foundation pile. S7: Pull out the casing (1) after the concrete is poured; In step S3, when the casing (1) is lifted to one end, the diameter expansion device (3) can be used to expand the diameter of the rammed head and form dense expansion holes. The expanding device (3) includes: The expansion assembly (31) is connected to the center of the tube plug (2) via a connector (33); An opening and closing door (32) is provided above the filling port of the casing (1) for placing and removing the expansion assembly (31) inside the casing (1); The diameter expansion assembly (31) includes: The connecting post (311) is fixedly connected to the sleeve (332); Multiple sets of expansion plates (312) are arranged in an array around the connecting column (311) with the connecting column (311) as the center. The multiple sets of expansion plates (312) and the connecting group are connected by telescopic members (313). Multiple sets of top columns (314) are evenly arranged on the outer wall of the expansion plate (312); Before the filling hole is enlarged, the enlargement component (31) is installed on the pipe plug (2) through the connector (33) from the opening and closing gate (32). Then, the pipe plug (2) is transported to the bottom of the casing (1) through the moving equipment on the pile driver, so that the enlargement component (31) is placed at the position where the casing (1) needs to be enlarged by one end of the lifting distance. Then, the expansion plate (312) is made to move in and out through the telescopic component (313). The telescopic movement of the expansion plate (312) causes the soil hole surface of the expansion plate (312) to be impacted, thereby increasing the radius at that point. At the same time, the setting of the top column (314) can form a hole when impacted. Thus, when the enlarged head is formed later, through this pretreatment, the radius of the enlarged head can be larger and the hole formed with the soil at that point can be more tightly and firmly combined after the filling.

2. The method for reinforcing the foundation of a building above an underground box culvert in a riverbank backfill area according to claim 1, characterized in that, In step S1, the pile position should be determined three times. The first measurement should be taken before the casing (1) is dug and the second measurement should be taken after the casing (1) is installed so that the deviation between the center of the casing (1) and the pile position is no more than 50mm. The pile position should be marked. Then, the elevation of the casing (1) should be measured with a level and the measurement record should be made. The third measurement should be taken after the pile foundation is in place and the pile foundation should be checked to see if it is aligned with the pile center mark. In addition, the center point of the pile position should be marked by the cross-stud method.

3. The method for reinforcing the foundation of a building above an underground box culvert in a riverbank backfill area according to claim 1, characterized in that: In step S2, the casing (1) should be kept perpendicular to the ground during tamping, and this can be checked by using a plumb bob.

4. The method for reinforcing the foundation of a building above an underground box culvert in a riverbank backfill area according to claim 1, characterized in that, The rammed and expanded piles formed by claim 1 are evenly distributed on both sides of the underground box culvert and maintain a distance of at least 1 meter from the underground box culvert to avoid affecting the underground box culvert.

5. The method for reinforcing the foundation of a building above an underground box culvert in a riverbank backfill area according to claim 1, characterized in that, The connector (33) includes a sleeve (331) located at the center of the plug (2) and a sleeve (332) connected to the sleeve (331).

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