Pre-excavation method for the platform for driving inclined rock piles in the reservoir bank drawdown area

Abstract

The present invention belongs to the technical field of bridge construction, and particularly relates to a pre-excavation method for a driving platform for inclined rock piles of a bridge in a drawdown area of ​​a reservoir bank. The method comprises the following steps: preparing a pilot pile, precisely positioning the pilot pile, driving the pilot pile, cleaning the driving platform, and lifting the pilot pile. The pre-excavation of the driving platform is completed before the supporting pile sinking process. When the supporting pile is sunk, its bottom end can contact the driving platform, and the actual insertion direction of the supporting pile is the same as the preset insertion direction. The supporting pile will not contact the inclined rock and tilt in the vertical direction, so that the supporting surface of the bridge has better flatness and does not need to be leveled later. The main force direction of the supporting pile is on its central axis, so that the supporting pile is evenly stressed and not easily broken, so as to solve the problem that when the bottom end of the supporting pile vibrates into the soil, it deviates from the preset driving direction due to the inclined force, thereby making the bridge construction surface uneven and the supporting pile easily broken.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a pre-excavation method for a platform for placing inclined rock piles in a reservoir bank drawdown zone. Background Art

[0002] The reservoir bank drawdown zone bridge is a bridge structure suitable for marine environments or waters with large waves. With the stability provided by supporting structures such as piles and columns, it has strong wind and wave resistance, enabling the bridge to withstand large wave impacts.

[0003] Some bridge piles in the reservoir bank drawdown zone require hammering or vibration to be sunk into the inclined rock. During sinking, the hard rock structure in the inclined rock causes the base of the pile to shift relative to the preset sinking position, causing the pile to deviate from the vertical. One practical approach is to ignore this offset and continue building the bridge. However, the offset piles will not provide sufficient support, reducing the overall support provided by the bridge. Another approach is to perform post-leveling, but the offset of each pile is random, making leveling more difficult and cumbersome. Furthermore, the piles are prone to breaking when they encounter hard rock and are subjected to the forces of tilt. This increases construction losses, costs, and disrupts the construction rhythm, significantly impacting the construction period. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for pre-excavating a platform for placing inclined rock piles in a reservoir bank drawdown zone, aiming to solve the above-mentioned technical problems in the prior art.

[0005] To achieve the above-mentioned object, the present invention provides a method for pre-excavating a platform for driving inclined rock pile columns in a bridge in a drawdown zone of a reservoir bank, wherein a pilot pile is used to excavate a platform for driving supporting pile columns before sinking supporting piles; the pilot pile is a hollow straight pile, and the ratio of the pile diameter to the supporting pile diameter is greater than 1; the method for pre-excavating a platform for driving inclined rock pile columns in a bridge in a drawdown zone of a reservoir bank comprises the following steps:

[0006] S100, pilot pile preparation:

[0007] Determine the pre-excavation sequence of pilot piles on the underwater inclined bare rock surface and select the pre-excavation points; complete the pilot pile processing;

[0008] S200, pilot pile fine positioning:

[0009] The pilot pile is transported to the pre-excavated bridge location using a lifting device and then transferred to a barge. The barge is then used to lay out cables to complete the ship's positioning.

[0010] Use a positioning device to locate the pre-installation point of the support pile. The pre-installation point of the support pile is set as the intersection between the center point of the bottom end of the support pile and the underwater oblique bare rock surface when the support pile is installed. Locate the outer injection point on the underwater oblique bare rock surface relative to the outer side of the pre-installation point of the support pile. The horizontal distance between the outer injection point and the pre-installation point of the support pile is equal to the radius of the support pile. Record the location of the outer injection point.

[0011] The pilot pile driving point is located according to the position of the outer driving point. The pilot pile driving point is set as the intersection between the center point of the pilot pile bottom and the underwater inclined bare rock surface when the pilot pile is driven. The horizontal distance between the pilot pile driving point and the outer driving point is equal to the radius of the pilot pile. The position of the pilot pile driving point is recorded.

[0012] S300, pilot pile injection:

[0013] Complete the pilot pile erection using a lifting device to secure the pilot pile to the stopper;

[0014] Adjust the limit device to complete the pilot pile driving positioning so that the center point of the pilot pile bottom end is vertically above the pilot pile driving point;

[0015] Use a vibratory hammer to vertically drive the pilot pile, so that the bottom end of the pilot pile is inserted into the underwater oblique bare rock surface; stop driving when the bottom surface of the pilot pile reaches the horizontal position of the outer driving point, and the pilot pile will surround a cylindrical area on the underwater oblique bare rock surface;

[0016] When a vibratory hammer is used to vertically drive a pilot pile, the underwater inclined bare rock surface causes the direction in which the pilot pile is inserted into the underwater inclined bare rock surface to be horizontally offset relative to the vertical direction, resulting in a horizontal offset between the outer side of the pilot pile and the outer driving point that is greater than 0 unit length and less than 0.5 unit length;

[0017] S400, cleaning of injection platform:

[0018] Use a drilling rig to complete the rock clearing in the cylindrical area inside the pilot pile, and set the horizontal plane where the outer injection point is located as the injection platform. The outer injection point is located at the intersection of the outer side of the injection platform and the underwater inclined bare rock surface;

[0019] S500, pilot pile lifting:

[0020] Use the lifting device to complete the lifting and removal of the pilot pile to use it for the next pre-excavation point;

[0021] Preferably, after step S500, support pile driving is performed; the support pile driving includes the following steps:

[0022] S610, using a hoisting device to complete the erection of the support piles, so as to fix the support piles on the limiting device;

[0023] S620: The vertical projection point of the pre-installed driving point of the support pile on the driving platform is set as the actual driving point of the support pile; the limit device is adjusted to complete the driving positioning of the support pile so that the center point of the bottom end of the support pile coincides with the actual driving point of the support pile;

[0024] S630. Use a vibratory hammer to vertically drive the support piles so that the bottom ends of the support piles are vertically inserted into the ground below the driving platform.

[0025] Preferably, in step S100, determining the pre-excavation order of the pilot piles includes the following steps:

[0026] S110. Calculate the required number of support piles, the approximate location of each support pile, and the diameter of each support pile based on the scale of the bridge and the geographical conditions in the reservoir bank drawdown area. Geographical conditions include water level fluctuations, water flow velocity, stratum properties, wave action, and seismic activity.

[0027] S120. Determine the number of pilot pile pre-excavations based on the number of supporting piles, where the number of pilot pile pre-excavations is equal to the number of supporting piles; determine the rough position of the pilot pile pre-excavation based on the rough position of each supporting pile, where the rough position of each supporting pile is the rough position of the pilot pile pre-excavation; determine the length of the pilot pile based on the underwater height of the rough position of the pilot pile pre-excavation, where the length of the pilot pile is greater than the underwater height of the rough position of the supporting pile; determine the diameter of the pilot pile based on the diameter of the supporting piles, where the ratio of the pilot pile diameter to the supporting pile diameter is 1.5;

[0028] S130: Determine the pilot pile pre-excavation sequence based on the number of pilot pile pre-excavations and the rough positions of the pilot pile pre-excavations; and process the pilot piles based on the length and diameter of the pilot piles.

[0029] Preferably, in the pilot pile processing of step S100, the pilot pile is rolled and welded using steel plates to form a hollow tube shape, and a reinforcement plate is welded to the bottom end of the pilot pile to enhance the pile body strength when the pilot pile is driven into the underwater inclined bare rock surface.

[0030] Compared with the prior art, the above one or more technical solutions in the method for pre-excavating the platform for installing inclined rock piles in the reservoir bank drawdown zone bridge provided by the embodiment of the present invention have at least one of the following technical effects:

[0031] 1. By pre-excavating the driving platform before the supporting pile sinking process, the bottom end of the supporting pile will contact the driving platform during the sinking process. The actual insertion direction of the supporting pile is the same as the preset insertion direction, and the supporting pile will not contact the inclined rock and tilt in the vertical direction, so that the supporting surface of the bridge construction has better flatness and does not require subsequent leveling; the main force direction of the supporting pile is on its central axis, so that the supporting pile is evenly stressed and not prone to breakage.

[0032] 2. During the pre-excavation work, the ratio between the diameter of the pilot pile and the diameter of the supporting pile is set so that the range of the pre-excavated injection platform covers the range required for the injection of the supporting piles and meets the injection requirements of the supporting piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the pilot pile positioning;

[0034] Figure 2 This is a schematic diagram of pilot pile injection;

[0035] Figure 3 This is a schematic diagram of support pile injection;

[0036] Figure 4 Flowchart of the pre-excavation method for the platform for the inclined rock piles of the bridge in the drawdown area of ​​the reservoir bank;

[0037] In the picture:

[0038] 1. Underwater sloping bare rock surface; 11. Injection platform; 111. External injection point;

[0039] 2. Support piles; d1, support pile radius; 211, support pile pre-installation point; 212, support pile actual installation point;

[0040] 3. Pilot pile; d2, pilot pile radius; 311, pilot pile driving point. DETAILED DESCRIPTION

[0041] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0042] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0044] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0045] In the first embodiment of the present invention, a method for pre-digging a platform for placing inclined rock piles in a reservoir bank drawdown zone is provided. Figure 1 and Figure 2 , using the pilot pile 3 to excavate the supporting pile driving platform 11 before the supporting pile 2 is sunk; the pilot pile 3 is set as a hollow straight pile, and the ratio of the pile diameter to the pile diameter of the supporting pile 2 is greater than 1, preferably 1.5; the following description uses an embodiment in which the ratio of the pile diameter of the pilot pile 3 to the pile diameter of the supporting pile 2 is 1.5. The pre-excavation method for the inclined rock pile driving platform of the bridge in the reservoir bank drawdown area includes the following steps:

[0046] S100, pilot pile 3 preparation:

[0047] Determine the pre-excavation order of the pilot pile 3 on the underwater inclined bare rock surface 1 and select the pre-excavation point; complete the processing of the pilot pile 3;

[0048] S200, pilot pile 3 fine positioning:

[0049] The pilot pile 3 is transported to the bridge position by a lifting device and transferred to a barge; the barge is used to wind and release the cable to complete the ship movement and positioning;

[0050] Use a positioning device to locate a pre-installation point 211 for the support pile. The pre-installation point 211 for the support pile is set to the intersection between the center point of the bottom end of the support pile 2 and the underwater oblique bare rock surface 1 when the support pile 2 is installed. Locate an outer injection point 111 on the underwater oblique bare rock surface 1, relative to the outer side of the pre-installation point 211 for the support pile (i.e., the side facing the seawater, the same applies below). The horizontal distance between the outer injection point 111 and the pre-installation point 211 for the support pile is equal to the radius d1 of the support pile 2. Record the position of the outer injection point 111.

[0051] The pilot pile driving point 311 is located based on the position of the outer driving point 111. The pilot pile driving point 311 is set to be the intersection between the center point of the bottom end of the pilot pile 3 and the underwater inclined bare rock surface 1 when the pilot pile 3 is driven. The horizontal distance between the pilot pile driving point 311 and the outer driving point 111 is equal to the radius d2 of the pilot pile 3. The position of the pilot pile driving point 311 is recorded.

[0052] S300, pilot pile 3 injection:

[0053] Using a lifting device to complete the erection of the pilot pile 3 to fix the pilot pile 3 on the limiting device;

[0054] Adjust the limit device to complete the pilot pile 3 injection positioning, so that the center point of the bottom end of the pilot pile 3 is located vertically above the pilot pile injection point 311;

[0055] A vibratory hammer is used to vertically drive the pilot pile 3 so that the bottom end of the pilot pile 3 is inserted into the underwater oblique bare rock surface 1; the driving is stopped when the bottom surface of the pilot pile 3 reaches the horizontal position of the outer driving point 111, and the pilot pile 3 surrounds a cylindrical area on the underwater oblique bare rock surface 1;

[0056] When the vibratory hammer is used to vertically drive the pilot pile 3, the underwater inclined bare rock surface causes the direction in which the pilot pile 3 is inserted into the underwater inclined bare rock surface 1 to be horizontally offset relative to the vertical direction, so that a horizontal offset greater than 0 unit length and less than 0.5 unit length is generated between the outer side of the pilot pile 3 and the outer driving point 111; the length unit of the horizontal distance between the outer side of the pilot pile 3 and the outer driving point 111 is consistent with the length unit of the diameter of the supporting pile 2 and the length unit of the diameter of the pilot pile 3. For example: the diameter of the supporting pile 2 is 1m, and the diameter of the pilot pile 3 is 1.5m. After the pilot pile 3 is driven, the horizontal distance between the outer side of the pilot pile 3 and the outer driving point 111 is greater than 0m and less than 0.5m.

[0057] S400, cleaning of injection platform 11:

[0058] Use a drilling rig to complete the rock cleaning of the cylindrical area inside the pilot pile 3, and set the plane where the horizontal position of the outer injection point 111 is located as the injection platform 11. The outer injection point 111 is located at the intersection of the outer side of the injection platform 11 and the underwater inclined bare rock surface 1. It should be noted that the maximum horizontal distance between the outer injection point 111 and the inner side of the injection platform 11 is greater than or equal to the diameter of the support pile 2, and the vertical projection point of the support pile pre-installation injection point 211 falls between the center of the injection platform 11 and the outer injection point 111.

[0059] S500, pilot pile 3 lifting:

[0060] The lifting and moving of the pilot pile 3 is completed using a lifting device so that the pilot pile 3 can be used for the next pre-excavation point.

[0061] Furthermore, after step S500, support piles are injected; Figure 3 , the support pile injection includes the following steps:

[0062] S610: Use a lifting device to complete the erection of the support pile 2 to fix the support pile 2 on the limiting device;

[0063] S620, the vertical projection point of the support pile pre-installation point 211 on the injection platform 11 is set as the support pile actual injection point 212; the limit device is adjusted to complete the injection positioning of the support pile 2 so that the center point of the bottom end of the support pile 2 coincides with the support pile actual injection point 212;

[0064] S630 , using a vibratory hammer to vertically drive the support pile 2 , so that the bottom end of the support pile 2 is vertically inserted into the ground below the driving platform 11 .

[0065] Furthermore, in step S100, determining the pre-excavation order of the pilot piles 3 includes the following steps:

[0066] S110. Calculate the required number of support piles 2, the approximate location of each support pile 2, and the diameter of each support pile 2 based on the scale of the bridge and the geographical conditions in the reservoir bank drawdown area; the geographical conditions include water level changes, water flow velocity, stratum properties, wave action, and seismic activity;

[0067] S120. Determine the number of pre-excavations for pilot piles 3 based on the number of supporting piles 2, where the number of pre-excavations for pilot piles 3 is equal to the number of supporting piles 2; determine the rough pre-excavation position of pilot piles 3 based on the rough position of each supporting pile 2, where the rough position of each supporting pile 2 is the rough pre-excavation position of pilot piles 3; determine the length of pilot piles 3 based on the underwater height of the rough pre-excavation position of pilot piles, where the length of pilot piles 3 is greater than the underwater height of the rough pre-excavation position of supporting piles; determine the diameter of pilot piles 3 based on the diameter of supporting piles 2, where the ratio of the diameter of pilot piles to the diameter of supporting piles is 1.5;

[0068] S130 , determining the pre-excavation order of the pilot piles 3 according to the number of pre-excavation of the pilot piles 3 and the rough pre-excavation positions of the pilot piles 3 ; and processing the pilot piles 3 according to the length and diameter of the pilot piles 3 .

[0069] Furthermore, in the pilot pile processing of step S100, the pilot pile 3 is rolled and welded using steel plates to form a hollow tube shape, and a reinforcement plate is welded to the bottom end of the pilot pile 3 to enhance the pile body strength when the pilot pile 3 is driven into the underwater inclined bare rock surface 1.

[0070] Except for the first embodiment, the undescribed parts in the remaining embodiments are the same as those in the first embodiment, and the unexplained features are all based on the explanations of the first embodiment.

[0071] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, its architecture can be flexible and varied, and a series of products can be derived. Simply making a few simple deductions or substitutions should be considered to fall within the scope of patent protection of the present invention as determined by the submitted claims.

Claims

1. A method for pre-excavating a platform for driving inclined rock piles in a reservoir bank drawdown zone, wherein a pilot pile is used to excavate the platform for driving supporting piles before sinking supporting piles; the method is characterized by: The pilot pile is set as a hollow straight pile, and the ratio of the pile diameter to the supporting pile diameter is greater than 1. The pre-excavation method for the inclined rock pile column driving platform of the bridge in the reservoir bank drawdown area includes the following steps: S100, pilot pile preparation: Determine the pre-excavation sequence of pilot piles on the underwater inclined bare rock surface and select the pre-excavation points; complete the pilot pile processing; S200, pilot pile fine positioning: The pilot pile is transported to the pre-excavated bridge location using a lifting device and then transferred to a barge. The barge is then used to lay out cables to complete the ship's positioning. Use a positioning device to locate the support pile pre-installation point, and the support pile pre-installation point is set to the intersection between the center point of the bottom end of the support pile and the underwater inclined bare rock surface when the support pile is installed; locate the outer driving point on the underwater inclined bare rock surface relative to the outer side of the support pile pre-installation point, and the horizontal distance between the outer driving point and the support pile pre-installation point is equal to the radius of the support pile; record the location of the outer driving point; The pilot pile driving point is located according to the position of the outer driving point. The pilot pile driving point is set as the intersection between the center point of the pilot pile bottom and the underwater inclined bare rock surface when the pilot pile is driven. The horizontal distance between the pilot pile driving point and the outer driving point is equal to the radius of the pilot pile. The position of the pilot pile driving point is recorded. S300, pilot pile injection: Complete the pilot pile erection using a lifting device to secure the pilot pile to the stopper; Adjust the limit device to complete the pilot pile driving positioning so that the center point of the pilot pile bottom end is vertically above the pilot pile driving point; Use a vibratory hammer to vertically drive the pilot pile, so that the bottom end of the pilot pile is inserted into the underwater oblique bare rock surface; stop driving when the bottom surface of the pilot pile reaches the horizontal position of the outer driving point, and the pilot pile will surround a cylindrical area on the underwater oblique bare rock surface; When a vibratory hammer is used to vertically drive a pilot pile, the underwater inclined bare rock surface causes the direction in which the pilot pile is inserted into the underwater inclined bare rock surface to be horizontally offset relative to the vertical direction, resulting in a horizontal offset between the outer side of the pilot pile and the outer driving point that is greater than 0 unit length and less than 0.5 unit length; S400, cleaning of injection platform: Use a drilling rig to complete the rock clearing in the cylindrical area inside the pilot pile, and set the horizontal plane where the outer injection point is located as the injection platform. The outer injection point is located at the intersection of the outer side of the injection platform and the underwater inclined bare rock surface; S500, pilot pile lifting: The pilot pile is lifted and moved using a lifting device so that it can be used for the next pre-excavation point.

2. The method for pre-excavating a platform for driving inclined rock piles in a reservoir bank drawdown zone according to claim 1 is characterized by: After step S500, the support piles are injected. The support pile injection includes the following steps: S610, using a hoisting device to complete the erection of the support piles, so as to fix the support piles on the limiting device; S620: The vertical projection point of the pre-installed driving point of the support pile on the driving platform is set as the actual driving point of the support pile; the limit device is adjusted to complete the driving positioning of the support pile so that the center point of the bottom end of the support pile coincides with the actual driving point of the support pile; S630. Use a vibratory hammer to vertically drive the support piles so that the bottom ends of the support piles are vertically inserted into the ground below the driving platform.

3. The method for pre-excavating a platform for placing inclined rock piles in a reservoir bank drawdown zone bridge according to claim 1, characterized in that: In step S100, determining the pre-excavation order of the pilot piles includes the following steps: S110. Calculate the required number of support piles, the approximate location of each support pile, and the diameter of each support pile based on the scale of the bridge and the geographical conditions in the reservoir bank drawdown area. Geographical conditions include water level fluctuations, water flow velocity, stratum properties, wave action, and seismic activity. S120. Determine the number of pilot pile pre-excavations based on the number of supporting piles, where the number of pilot pile pre-excavations is equal to the number of supporting piles; determine the rough position of the pilot pile pre-excavation based on the rough position of each supporting pile, where the rough position of each supporting pile is the rough position of the pilot pile pre-excavation; determine the length of the pilot pile based on the underwater height of the rough position of the pilot pile pre-excavation, where the length of the pilot pile is greater than the underwater height of the rough position of the supporting pile; determine the diameter of the pilot pile based on the diameter of the supporting piles, where the ratio of the pilot pile diameter to the supporting pile diameter is 1.5; S130: Determine the pilot pile pre-excavation sequence based on the number of pilot pile pre-excavations and the rough positions of the pilot pile pre-excavations; and process the pilot piles based on the length and diameter of the pilot piles.

4. The method for pre-excavating a platform for placing inclined rock piles in a reservoir bank drawdown zone bridge according to claim 1, characterized in that: In the pilot pile processing of step S100, the pilot pile is rolled and welded using steel plates to form a hollow tube shape, and a reinforcement plate is welded to the bottom end of the pilot pile to enhance the pile body strength when the pilot pile is driven into the underwater inclined bare rock surface.

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