A method and system for pile demolition and pile hole backfilling

Abstract

This application relates to the field of basic engineering technology and discloses a method and system for pile foundation demolition and pile hole backfilling. The method disclosed in this application includes acquiring pile foundation data, analyzing the spatial relationship data between the proposed tunnel and the pile foundation based on the tunnel design scheme and the pile foundation data, and constructing a proposed tunnel reinforcement scheme; determining the planar range and vertical depth of pile foundation demolition within the pile foundation demolition zone based on the spatial relationship data and the proposed tunnel reinforcement scheme; and determining the pile hole backfilling depth and the materials required for pile hole backfilling based on the planar range and vertical depth of pile foundation demolition. This invention is universally applicable when encountering various pile foundation obstacles during shield tunnel construction, enabling rapid and scientific selection of pile foundation demolition and pile hole backfilling schemes, ensuring the rationality of the planar range and vertical depth of pile foundation demolition, the reliability of pile hole backfilling, and ultimately ensuring the safety of shield tunneling construction.

Description

Technical Field

[0001] This invention relates to the field of foundation engineering technology, specifically to a method and system for pile breaking and pile hole backfilling. Background Technology

[0002] With the large-scale construction of urban subways, subway lines are frequently laid in densely built-up urban areas. Tunnel boring machines (TBMs) often encounter underground obstacles in these areas, especially large areas of pile foundations, which pose significant obstacles and risks to TBM construction. Current technology lacks unified regulations and technical guidelines for pile foundation removal and backfilling in TBM construction areas. Engineering technicians rely on their experience to determine the scope and depth of removal. Excessive removal may lead to excessively high project costs and waste, or inconsistent quality in the handling of pile foundation obstacles may compromise the safety of TBM construction.

[0003] In summary, in densely built-up urban areas with underground pile foundations, the determination of whether the pile foundation needs to be demolished, the scope and depth of demolition, and the depth and materials for backfilling the pile holes after demolition have become urgent technical problems that need to be solved when shield tunnel construction crosses the pile foundation. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for pile demolition and pile hole backfilling, thereby solving the technical problems mentioned in the background section. To achieve this objective, the present invention provides the following technical solution: a method for pile demolition and pile hole backfilling, comprising:

[0005] Obtain pile foundation data, and based on the tunnel design scheme and pile foundation data, analyze the spatial relationship data between the proposed tunnel and the pile foundation, and construct a proposed tunnel reinforcement scheme;

[0006] Based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement plan, the planar range and vertical depth of pile foundation removal in the pile foundation removal zone are determined.

[0007] Based on the planar extent and vertical depth of pile foundation demolition, determine the backfill depth of the pile holes and the materials required for backfilling.

[0008] Preferably, the proposed tunnel reinforcement scheme includes at least one or more of the following: no reinforcement required, cement-soil mixing pile reinforcement, and in-tunnel grouting reinforcement.

[0009] Preferably, the spatial relationship data between the tunnel and the pile foundation includes at least one of the following: data on the pile foundation not encroaching on the tunnel construction area and data on the pile foundation encroaching on the tunnel construction area.

[0010] Preferably, based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme, the determination of the planar range and vertical depth of pile foundation removal within the pile foundation removal zone includes:

[0011] If the proposed tunnel reinforcement plan is one that does not require reinforcement, then it is necessary to further determine whether the pile foundation encroaches on the tunnel construction area;

[0012] If the pile foundation does not intrude into the tunnel construction area, then the values ​​of the horizontal range of the pile foundation demolition and the vertical depth of the pile foundation demolition are both zero.

[0013] If the pile foundation intrudes into the tunnel construction area, the value of the pile foundation demolition plane range shall be 0.5m to 1m above the tunnel outer contour value, and the value of the pile foundation demolition vertical depth shall be at least 0.5m above the depth value below the tunnel outer contour value.

[0014] Preferably, based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme, the determination of the planar range and vertical depth of pile foundation removal within the pile foundation removal zone includes:

[0015] If the proposed reinforcement scheme for the tunnel is cement-soil mixing pile reinforcement, the value of the horizontal range of the pile foundation removal shall be 0.5m to 1.5m greater than the value of the outer contour of the mixing pile reinforcement area, and the value of the vertical depth of the pile foundation removal shall be at least 1m greater than the value of the depth below the outer contour of the mixing pile reinforcement area.

[0016] Preferably, based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme, the determination of the planar range and vertical depth of pile foundation removal within the pile foundation removal zone includes:

[0017] If the proposed tunnel reinforcement scheme is an in-tunnel grouting reinforcement scheme, then it is necessary to further determine whether the pile foundation intrudes into the tunnel construction area;

[0018] If the pile foundation does not intrude into the tunnel construction area, then the values ​​of the horizontal range of the pile foundation demolition and the vertical depth of the pile foundation demolition are both zero.

[0019] If the pile foundation intrudes into the tunnel construction area, the value of the horizontal range of the pile foundation removal shall be 0m to 0.5m greater than the outer contour value of the grouting reinforcement zone inside the tunnel, and the value of the vertical depth of the pile foundation removal shall be at least 1m greater than the depth value below the outer contour value of the grouting reinforcement zone inside the tunnel.

[0020] Preferably, the backfill depth of the pile hole is determined based on the planar extent and vertical depth of the pile foundation demolition, including:

[0021] If both the planar extent and vertical depth of the pile foundation demolition are zero, then the backfill depth of the pile hole is zero.

[0022] If the horizontal range and vertical depth of the pile foundation demolition increase, the backfill depth of the pile hole shall not be less than 30m.

[0023] Preferably, the materials required for backfilling the pile holes are determined based on the planar extent and vertical depth of the pile foundation demolition, including:

[0024] If both the horizontal range and vertical depth of the pile foundation demolition are zero, then no material is required for backfilling the pile holes.

[0025] If the horizontal range and vertical depth of the pile foundation demolition increase, the materials required for backfilling the pile holes will be either cement mortar or sand.

[0026] Preferably, if the materials required for backfilling the pile holes are cement mortar and sand, the backfilling depth of cement mortar shall not be less than 13m, and the depth from the top surface of the backfilled cement mortar to the outer contour of the tunnel shall not be less than 6m, and the backfilling depth of sand on the top surface of cement mortar shall not be less than 16m.

[0027] If the material required for backfilling the pile hole is sand, then the backfilling depth of the sand in the pile hole shall not be less than 30m.

[0028] Preferably, a pile breaking and pile hole backfilling system includes:

[0029] The reinforcement scheme construction unit is used to obtain pile foundation data, and based on the tunnel design scheme and pile foundation data, analyze the spatial relationship data between the proposed tunnel and the pile foundation and construct the proposed tunnel reinforcement scheme.

[0030] The pile foundation demolition data acquisition unit is used to determine the horizontal range and vertical depth of pile foundation demolition in the pile foundation demolition zone based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme.

[0031] The pile hole backfill depth acquisition unit is used to determine the pile hole backfill depth based on the pile foundation demolition plane range and pile foundation demolition vertical depth.

[0032] The material acquisition unit for pile hole backfilling is used to determine the materials required for pile hole backfilling based on the horizontal range and vertical depth of pile foundation demolition.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] This invention patent is universally applicable when encountering various pile foundation obstacles during shield tunnel construction. Engineering technicians can quickly and scientifically select pile foundation removal and pile hole backfilling schemes, ensuring the rationality of the pile foundation removal plane range and vertical depth, the reliability of pile hole backfilling, and ultimately ensuring the safety of shield tunnel construction. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the planar area for pile foundation demolition when the tunnel does not require reinforcement.

[0036] Figure 2This is a schematic diagram showing the vertical depth of pile foundation demolition and the backfill range when the tunnel does not require reinforcement.

[0037] Figure 3 This is a schematic diagram of the planar extent of pile foundation demolition under the condition of mixed-mixing pile reinforcement.

[0038] Figure 4 This is a schematic diagram showing the vertical depth of pile foundation demolition and the backfill range under the condition of mixed-mixing pile reinforcement.

[0039] Figure 5 This is a schematic diagram of the planar range of pile foundation demolition under the condition of grouting reinforcement inside the tunnel.

[0040] Figure 6 This is a schematic diagram showing the vertical depth of pile foundation demolition and the backfill range under the grouting reinforcement condition inside the tunnel.

[0041] In the diagram: 1. Pile foundation; 2. Outer contour of the tunnel; 3-1. Planar range of pile foundation demolition; 3-2. Vertical depth of pile foundation demolition; 4. Mixing pile reinforcement zone; 5. Grouting reinforcement zone inside the tunnel; 6-1. Cement mortar; 6-2. Sand; 7. Ground surface; 8. Bottom of self-pumping pile. Detailed Implementation

[0042] 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.

[0043] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The following describes embodiments of the invention based on its overall structure.

[0044] Example 1:

[0045] A method for pile demolition and pile hole backfilling includes:

[0046] Obtain pile foundation data, and based on the tunnel design scheme and pile foundation data, analyze the spatial relationship data between the proposed tunnel and the pile foundation, and construct a proposed tunnel reinforcement scheme;

[0047] Based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement plan, the planar range and vertical depth of pile foundation removal in the pile foundation removal zone are determined.

[0048] Based on the planar extent and vertical depth of pile foundation demolition, determine the backfill depth of the pile holes and the materials required for backfilling.

[0049] When the length of the pile foundation embedded in the ground (from the bottom of the self-driven pile to the ground depth) is 30m, a simplified table for determining the scope of pile foundation demolition and pile hole backfilling is as follows:

[0050]

[0051]

[0052] When encountering a pile foundation 1 (30m in length) obstacle within the tunnel construction area, a suitable pile foundation removal and pile hole backfilling scheme can be determined based on the aforementioned pile foundation removal range and pile hole backfilling discrimination table. Note: The hole formed between the original pile foundation 1 and the soil is called a pile hole.

[0053] The first embodiment of this invention uses a pile hole backfilling depth of 30m (when the depth from the bottom of the self-impact pile to the ground is 30m) for explanation. The data for different filling materials corresponding to the three proposed tunnel reinforcement schemes are as follows: If the pile foundation 1 or the pile hole backfilling depth is greater than 30m, such as 40m, 50m, 60m, 65m, etc., the cement mortar and sand that do not need reinforcement can be implemented in a 13:17 ratio, the cement mortar and sand in the grouting reinforcement in the tunnel can be implemented in a 7:8 ratio, and the sand in the cement-soil mixing pile reinforcement can be completely filled.

[0054] Example 2: The following applies when the length of the pile foundation buried in the ground (from the bottom of the self-impacting pile to the ground depth) exceeds 30m:

[0055] 1. The pile foundation demolition area 3-1 and the pile foundation demolition depth 3-2 in the pile foundation demolition zone are divided into:

[0056] like Figure 1 and Figure 2As shown, when the tunnel is located in a good stratum and no reinforcement treatment is required: only the needs of shield tunneling need to be considered. If pile 1 does not intrude into the tunnel, there is no need to break pile 1. If pile 1 intrudes into the tunnel, the pile foundation breaking plane range 3-1 is 0.5 to 1m more than the value of the tunnel outer contour 2, and the pile foundation breaking vertical depth 3-2 is at least 0.5m more than the value of the depth below the tunnel outer contour 2.

[0057] The backfilling depth of the pile holes and the materials required for backfilling the pile holes:

[0058] The tunnel is located in relatively good geological strata and requires no reinforcement: if pile 1 does not intrude into the tunnel, the pile hole does not need to be backfilled; if pile 1 intrudes into the tunnel construction area, pile 1 should be demolished. Figure 2 The self-impacting pile bottom 8 in the pile hole is backfilled with cement mortar 6-1. The backfilling depth of cement mortar 6-1 is not less than 13m, and the depth from the top surface of the backfilled cement mortar 6-1 to the outer contour of the tunnel is not less than 6m. The backfilling depth of sand 6-2 on the top surface of cement mortar 6-1 in the pile hole is not less than 17m. The cement mortar 6-1 backfill has a certain strength, but the strength grade is low, so that the shield cutter can smoothly cut the cement mortar 6-1 backfill and complete the construction of the shield tunnel. At the same time, the cement mortar 6-1 backfill has low permeability, which can prevent the formation of water-permeable channels in the pile hole and ensure the safety of shield tunnel excavation.

[0059] 2. The pile foundation demolition area 3-1 and the pile foundation demolition depth 3-2 in the pile foundation demolition zone are divided into:

[0060] like Figure 3 and Figure 4 As shown, when the tunnel is located in a soft stratum and cement-soil mixing piles are needed to reinforce a certain area of ​​the tunnel's outer contour 2, the conditions of both shield tunneling and cement-soil mixing pile reinforcement construction must be considered simultaneously. Therefore, regardless of whether the pile foundation 1 intrudes into the tunnel, the horizontal range 3-1 of the pile foundation removal is 0.5 to 1.5m greater than the outer contour value of the mixing pile reinforcement area 4, and the vertical depth 3-2 of the pile foundation removal is at least 1m greater than the depth value below the outer contour of the mixing pile reinforcement area 4.

[0061] The backfilling depth of the pile holes and the materials required for backfilling the pile holes:

[0062] The tunnel is located in a soft stratum. A certain area of ​​the tunnel's outer contour 2 is reinforced with cement mixing to form a cement mixing pile reinforcement zone 4. Considering that the materials required for backfilling the pile holes do not affect the construction of the cement mixing pile reinforcement zone 4, regardless of whether the pile foundation 1 encroaches on the tunnel construction area, if... Figure 4 The bottom of the self-impacting piles in the pile holes, from the pile bottom (8) to the ground surface (7), a depth of not less than 30m, was backfilled and compacted with sand (6-2). After backfilling, the pile holes were constructed with mixing piles to form a reinforced body that meets the design strength and permeability requirements. Finally, the shield tunnel excavation construction passed through the mixing pile reinforced zone (4).

[0063] 3. The pile foundation demolition area 3-1 and the pile foundation demolition depth 3-2 in the pile foundation demolition zone are divided into:

[0064] like Figure 5 and Figure 6 As shown, when the tunnel is located in a soft stratum and requires grouting reinforcement of a certain area of ​​the tunnel's outer contour 2: if the pile foundation 1 does not intrude into the tunnel construction area, then there is no need to break the pile foundation 1; if the pile foundation 1 intrudes into the tunnel construction area, then the pile foundation breaking plane range 3-1 is 0-0.5m more than the outer contour value of the grouting reinforcement zone 5, and the pile foundation breaking vertical depth 3-2 is at least 1m more than the depth value below the outer contour value of the grouting reinforcement zone 5.

[0065] The backfilling depth of the pile holes and the materials required for backfilling the pile holes:

[0066] The tunnel is located in soft strata. Grouting reinforcement is implemented within a certain area of ​​the tunnel's outer contour 2. If pile foundation 1 does not intrude into the tunnel construction area, it is not necessary to remove pile foundation 1, and the pile holes do not need to be backfilled. If pile foundation 1 intrudes into the tunnel construction area, then, after removing pile foundation 1, if... Figure 6 The bottom of the self-pumping piles 8 in the pile holes is backfilled with cement mortar 6-1. The backfilling depth of cement mortar 6-1 is not less than 16m, and the depth from the top surface of the backfilled cement mortar 6-1 to the outer contour of the tunnel is not less than 6m. The backfilling depth of sand 6-2 above the cement mortar 6-1 in the pile holes is not less than 14m. After the pile holes are backfilled, shield tunneling is carried out. The cement mortar 6-1 backfill has a certain strength, but the strength grade is low, so the shield cutter can cut the backfilled pile body smoothly. At the same time, the cement mortar 6-1 backfill has low permeability, which can prevent the formation of water-permeable channels in the pile holes and ensure the safety of shield tunneling. After the tunnel structure is completed, grouting is carried out on the lower half of the tunnel outer contour 2, which ultimately forms the grouting reinforcement zone 5 inside the tunnel.

[0067] A system for demolishing foundation piles and backfilling pile holes, the system comprising:

[0068] The reinforcement scheme construction unit is used to obtain pile foundation data, and based on the tunnel design scheme and pile foundation data, analyze the spatial relationship data between the proposed tunnel and the pile foundation and construct the proposed tunnel reinforcement scheme.

[0069] The pile foundation demolition data acquisition unit is used to determine the horizontal range and vertical depth of pile foundation demolition in the pile foundation demolition zone based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme.

[0070] The pile hole backfill depth acquisition unit is used to determine the pile hole backfill depth based on the pile foundation demolition plane range and pile foundation demolition vertical depth.

[0071] The material acquisition unit for pile hole backfilling is used to determine the materials required for pile hole backfilling based on the horizontal range and vertical depth of pile foundation demolition.

[0072] In response to the above situations, this invention patent is universally applicable when encountering various pile foundation obstacles during shield tunnel construction. Engineering technicians can quickly and scientifically select pile foundation removal and pile hole backfilling schemes, and organize on-site implementation to ensure the rationality of the pile foundation removal plane range and pile foundation removal vertical depth, the reliability of pile hole backfilling, and ultimately ensure the safety of shield tunnel construction.

[0073] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the invention, and no reference numerals in the claims should be regarded as limiting the scope of the claims.

Claims

1. A method for breaking up foundation piles and backfilling pile holes, characterized in that, Includes the following steps: Obtain pile foundation data, and based on the tunnel design scheme and the pile foundation data, analyze the spatial relationship data between the proposed tunnel and the pile foundation, and construct a proposed tunnel reinforcement scheme; Based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme, the planar range and vertical depth of pile foundation removal in the pile foundation removal zone are determined, specifically including: If the proposed tunnel reinforcement scheme is one that does not require reinforcement, then it is further determined whether the pile foundation encroaches on the tunnel construction area; If the pile foundation does not intrude into the tunnel construction area, then the values ​​of the pile foundation demolition plane range and the pile foundation demolition vertical depth are both zero; If the pile foundation intrudes into the tunnel construction area, the value of the pile foundation demolition plane range shall be 0.5m to 1m above the tunnel outer contour value, and the value of the pile foundation demolition vertical depth shall be at least 0.5m above the depth value below the tunnel outer contour. Based on the planar range and vertical depth of the pile foundation demolition, determine the backfill depth of the pile hole and the materials required for backfilling.

2. The method for pile demolition and pile hole backfilling according to claim 1, characterized in that: The spatial relationship data between the tunnel and the pile foundation includes at least one of the following: data on the pile foundation not encroaching on the tunnel construction area and data on the pile foundation encroaching on the tunnel construction area.

3. The method for pile demolition and pile hole backfilling according to claim 1, characterized in that, Based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme, the planar range and vertical depth of pile foundation removal in the pile foundation removal zone are determined as follows: If the proposed tunnel reinforcement scheme is a cement-soil mixing pile reinforcement scheme, then the value of the pile foundation demolition plane range is 0.5m to 1.5m greater than the value of the outer contour of the mixing pile reinforcement area, and the value of the pile foundation demolition vertical depth is at least 1m greater than the value of the depth below the outer contour of the mixing pile reinforcement area.

4. The method for pile demolition and pile hole backfilling according to claim 1, characterized in that, Based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme, the planar range and vertical depth of pile foundation removal in the pile foundation removal zone are determined as follows: If the proposed tunnel reinforcement scheme is an in-tunnel grouting reinforcement scheme, then it is necessary to further determine whether the pile foundation intrudes into the tunnel construction area; If the pile foundation does not intrude into the tunnel construction area, then the values ​​of the pile foundation demolition plane range and the pile foundation demolition vertical depth are both zero; If the pile foundation intrudes into the tunnel construction area, the value of the pile foundation demolition plane range is 0m~0.5m greater than the outer contour value of the grouting reinforcement zone inside the tunnel, and the value of the pile foundation demolition vertical depth is at least 1m greater than the depth value below the outer contour value of the grouting reinforcement zone inside the tunnel.

5. The method for pile demolition and pile hole backfilling according to claim 1, characterized in that, Based on the planar extent and vertical depth of the pile foundation demolition, the backfill depth of the pile holes is determined, including: If both the horizontal range of the pile foundation demolition and the vertical depth of the pile foundation demolition are zero, then the backfill depth of the pile hole is zero. If at least one of the planar extent of the pile foundation demolition and the vertical depth of the pile foundation demolition is not zero, then the backfill depth of the pile hole shall not be less than 30m.

6. The method for pile breaking and pile hole backfilling according to claim 5, characterized in that, Based on the planar extent and vertical depth of the pile foundation demolition, determine the materials required for backfilling the pile holes, including: If both the horizontal range of the pile foundation demolition and the vertical depth of the pile foundation demolition are zero, then no material is required for backfilling the pile hole. If the plane range of the pile foundation demolition and the vertical depth of the pile foundation demolition increase, the material required for backfilling the pile hole is one or both of cement mortar and sand.

7. The method for pile demolition and pile hole backfilling according to claim 6, characterized in that, If the materials required for backfilling the pile holes are cement mortar and sand, the backfilling depth of cement mortar shall not be less than 13m, and the depth from the top surface of the backfilled cement mortar to the outer contour of the tunnel shall not be less than 6m, and the backfilling depth of sand on the top surface of cement mortar shall not be less than 16m. If the material required for backfilling the pile hole is sand, then the backfilling depth of the sand in the pile hole shall not be less than 30m.

8. A system for demolishing and backfilling foundation piles, implementing the method for demolishing and backfilling foundation piles as described in claim 1, characterized in that, The system includes: A reinforcement scheme construction unit is used to acquire pile foundation data, and based on the tunnel design scheme and the pile foundation data, analyze the spatial relationship data between the proposed tunnel and the pile foundation and construct the proposed tunnel reinforcement scheme. A pile foundation demolition data acquisition unit is used to determine the pile foundation demolition plane range and pile foundation demolition vertical depth in the pile foundation demolition zone based on the spatial relationship data between the tunnel and the pile foundation and the proposed tunnel reinforcement scheme. A pile hole backfill depth acquisition unit is used to determine the pile hole backfill depth based on the pile foundation demolition plane range and the pile foundation demolition vertical depth. A material acquisition unit for pile hole backfilling is used to determine the materials required for pile hole backfilling based on the horizontal range and vertical depth of pile foundation demolition.

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