Foundation pit engineering axial force servo inclined pile support and construction method thereof

Abstract

The application discloses a foundation pit engineering axial force servo inclined pile support and a construction method thereof, and aims to provide the foundation pit engineering axial force servo inclined pile support and the construction method thereof which can not only optimize a construction process step and shorten a construction period, but also actively control foundation pit deformation and effectively avoid the problem that the inclined pile support effect is weakened due to the compression deformation of the bottom soil body of the inclined pile. The foundation pit engineering axial force servo inclined pile support comprises a foundation pit support pile, a top pressing beam is arranged at the top of the foundation pit support pile, the inclined pile comprises a support inclined pile and a top inclined pile, the upper end of the top inclined pile is connected with the top pressing beam in an integrated mode, and the support inclined pile is inserted into the foundation pit soil body; the servo loading device comprises a jack, the jack is located between the lower end of the top inclined pile and the upper end of the support inclined pile, the jack applies axial force between the top inclined pile and the support inclined pile along the axial direction of the inclined pile, and thus the foundation pit soil body at the bottom of the support inclined pile is actively compressed.

Description

Technical Field

[0001] This invention relates to the field of foundation pit engineering, and specifically to an axial force servo inclined pile support for foundation pit engineering and its construction method. Background Technology

[0002] As my country's urbanization process continues to advance and the development and utilization of underground space deepens, the number of deep and large foundation pit projects in urban core areas is also increasing. Compared with conventional projects, deep and large foundation pit projects usually have more stringent requirements for foundation pit deformation control due to their proximity to dense buildings, subways, stations, tunnels, and other complex surrounding environments.

[0003] Currently, the internal bracing used in foundation pit retaining structures is typically horizontal. However, when the foundation pit is large, the horizontal internal bracing beams have large spans, and due to their excessive length, they deform significantly under the influence of external soil and water pressure. They are also highly susceptible to thermal expansion and contraction. This results in high costs for the bracing and an inability to effectively control foundation pit deformation. Furthermore, when site conditions permit, using internal bracing is wasteful when sloping only one side of the foundation pit.

[0004] To address the aforementioned shortcomings, some inventors have adopted a support method combining retaining piles and inclined piles. This method optimizes the construction sequence and shortens the construction period. However, the retaining pile + inclined pile support method is generally used in soft soil areas and has the following drawbacks in practical applications: when the inclined piles are driven into the ground, the compression and deformation of the soil at the pile bottom will affect the efficiency of foundation pit deformation control; during the foundation pit construction process, as the soil at the pile bottom further compresses and deforms, the effect of the inclined pile support will gradually weaken. Summary of the Invention

[0005] The purpose of this invention is to provide an axial force servo inclined pile support for foundation pit engineering and its construction method, which can not only optimize the construction process and shorten the construction cycle, but also actively control the deformation of the foundation pit and effectively avoid the problem of excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined pile, which weakens the support effect of the inclined pile.

[0006] The technical solution of this invention is: A type of axial force servo inclined pile support for foundation pit engineering, comprising: The foundation pit retaining piles are topped with a capping beam. Inclined piles include supporting inclined piles and top inclined piles. The upper end of the top inclined pile is integrated with the capping beam, and the lower end of the top inclined pile is inclined towards the inside of the foundation pit. The supporting inclined pile is inserted into the soil of the foundation pit, and the upper end of the supporting inclined pile is inclined towards the direction of the foundation pit retaining pile, and the upper end of the supporting inclined pile faces the lower end of the top inclined pile. The servo loading device includes a jack located between the lower end of the top inclined pile and the upper end of the supporting inclined pile. The jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile.

[0007] This scheme utilizes a combination of retaining piles and inclined piles for support in the foundation pit. After the inclined piles are constructed, the foundation pit excavation can be completed in one go, without interfering with the underground structure construction. This optimizes the construction process and shortens the construction cycle. More importantly, a servo loading device applies axial force along the inclined pile axis between the top inclined pile and the supporting inclined pile, actively compressing the foundation pit soil at the bottom of the supporting inclined pile. This proactively controls foundation pit deformation and effectively avoids the problem of excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined pile, which weakens the inclined pile support effect. Furthermore, during foundation pit construction, the axial force can be increased by adjusting the jacks to actively control foundation pit deformation, further effectively preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined pile, which weakens the inclined pile support effect.

[0008] Preferably, the servo loading device further includes an axial force locking device, which comprises a screw and a threaded sleeve threadedly connected to the screw. The axial direction of the screw is parallel to the axial direction of the inclined pile, and the screw and threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile. Thus, after the servo loading device applies axial force, the threaded sleeve can be rotated to lock the axial force applied by the servo loading device onto the inclined pile, ensuring that the screw and threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile.

[0009] Preferably, the servo loading device also includes an upper end plate and a lower end plate. The upper end plate is fixed to the lower end of the top inclined pile, and the lower end plate is fixed to the upper end of the supporting inclined pile. In this way, the lower end of the top inclined pile and the upper end of the supporting inclined pile can be protected, ensuring that the axial force applied by the servo loading device can smoothly act on the lower inclined pile.

[0010] Preferably, the supporting inclined piles are composed of lattice columns.

[0011] Preferably, the top inclined pile is a concrete pile.

[0012] As a preferred option, the jack is a hydraulic servo jack.

[0013] A construction method for axial force servo inclined pile support in foundation pit engineering includes the following steps in sequence. First, construct retaining piles around the foundation pit; Second, construct the supporting inclined piles, inserting the supporting inclined piles into the soil inside the foundation pit on the inside side of the foundation pit retaining piles; Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and reserve inclined pile inserts at the top inclined pile position. Part of the inclined pile inserts extend to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile; Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device. Fifth, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile; Sixth, continue excavating the soil downwards. A servo loading device is used to apply axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the soil at the bottom of the supporting inclined pile. This actively controls the deformation of the foundation pit, effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles. Simultaneously, during the foundation pit construction process, the axial force applied by increasing the adjusting jacks can be used to actively control the deformation of the foundation pit, further effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles.

[0014] As a preferred option, in the sixth step, during the continued downward excavation of the soil, the deformation of the retaining piles in the foundation pit is monitored. When the deformation of the top of the retaining piles towards the inside of the foundation pit exceeds a set value, the jacks increase the axial force applied between the top inclined pile and the supporting inclined pile to control the deformation of the retaining piles in the foundation pit.

[0015] A construction method for axial force servo inclined pile support in foundation pit engineering includes the following steps in sequence. First, construct retaining piles around the foundation pit; Second, construct the inclined piles for support. Use a jet grouting machine to construct a section of cement-soil mixing pile at a set depth in the foundation pit soil. Then, before the cement-soil mixing pile solidifies, press the lattice column into the foundation pit soil and insert the lower end of the lattice column into the cement-soil mixing pile. Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and reserve inclined pile inserts at the top inclined pile position. Part of the inclined pile inserts extend to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile; Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device. Fifth, after the cement-soil mixing pile and the top inclined pile have solidified, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile. Sixth, continue excavating downwards. A servo loading device applies axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the soil at the bottom of the supporting inclined pile. This actively controls the foundation pit deformation, effectively preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles, which weakens the inclined pile support effect. More importantly, since the lower end of the lattice column is inserted into the cement-soil mixing pile, the servo loading device applies axial force, which actively compresses the foundation pit soil at the pile bottom through the cement-soil mixing pile. This effectively improves the soil's support capacity for the inclined pile, further preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles. Furthermore, during foundation pit construction, the axial force can be increased by adjusting the jacks to actively control foundation pit deformation, further preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles, which weakens the inclined pile support effect.

[0016] A construction method for axial force servo inclined pile support in foundation pit engineering includes the following steps in sequence. First, construct retaining piles around the foundation pit; Second, construct inclined piles to support the construction. An inclined pile deflection alarm device is installed on the top of the supporting inclined pile. The inclined pile deflection alarm device includes: The base is fixed to the top of the supporting inclined pile, and the base is equipped with an inclined guide rod that extends along the axial direction of the supporting inclined pile. Floating pressure plate, the floating pressure plate slides along the inclined guide rod; Compression spring, between the compression spring support base and the floating pressure plate; An alarm is fixed to the base and located between the base and the floating pressure plate. A jet grouting machine is used to construct inclined cement-soil mixing piles within the foundation pit soil. Next, before the cement-soil mixing pile solidifies, the lattice column is pressed into the cement-soil mixing pile, specifically including the following steps: a. The press machine applies pressure to the lattice column through the floating pressure plate, pressing the lattice column into the cement-soil mixing pile. During this process, if the pressing direction of the lattice column is inconsistent with the inclination angle of the cement-soil mixing pile, the lower end of the lattice column will be inserted into the soil outside the cement-soil mixing pile. After the lower end of the lattice column is inserted into the soil outside the cement-soil mixing pile, the floating pressure plate will overcome the force of the compression spring and move down along the inclined guide rod. When the floating pressure plate touches the alarm, the alarm will sound. At this time, the press machine stops applying pressure, allowing the floating pressure plate to reset under the action of the compression spring and separate from the alarm. b. The operator adjusts the pressing angle of the lattice column to make the pressing angle of the lattice column consistent with the inclination angle of the cement-soil mixing pile. Then, return to step a until the lattice column is completely pressed into the cement-soil mixing pile. c. Remove the inclined pile deflection alarm device from the supporting inclined pile; Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and reserve inclined pile inserts at the top inclined pile position. Part of the inclined pile inserts extend to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile; Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device. Fifth, after the cement-soil mixing pile and the top inclined pile have solidified, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile. Sixth, continue excavating the soil downwards. A servo loading device applies axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the soil at the bottom of the supporting inclined pile. This actively controls the deformation of the foundation pit, effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles. More importantly, since the lattice column is inserted entirely into the cement-soil mixing pile, the servo loading device applies axial force, which actively compresses the soil at the bottom of the pile through the cement-soil mixing pile. This effectively improves the support capacity of the soil at the bottom of the pile for the inclined pile, further preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined pile. Simultaneously, the combination of cement-soil mixing piles and lattice columns further enhances the support capacity of the inclined piles. Furthermore, during the foundation pit construction process, the axial force can be increased by adjusting the jacks to actively control the deformation of the foundation pit, further effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles.

[0017] The beneficial effects of this invention are: it can not only optimize the construction process and shorten the construction cycle, but also actively control the deformation of the foundation pit, effectively avoiding the problem of excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined pile, which weakens the support effect of the inclined pile. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a structure of an axial force servo inclined pile support for foundation pit engineering, which is a specific embodiment of the present invention.

[0019] Figure 2 This is a partial structural diagram of the servo loading device in the axial force servo inclined pile support of the foundation pit project according to a specific embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of a structure of an axial force servo inclined pile support for foundation pit engineering, which is a specific embodiment of the present invention.

[0021] Figure 4This is a schematic diagram of a structure of an axial force servo inclined pile support for foundation pit engineering, which is a specific embodiment of the present invention, in the fourth embodiment.

[0022] Figure 5 This is a schematic diagram of a inclined pile deflection alarm device used in the construction method of axial force servo inclined pile support for foundation pit engineering according to a specific embodiment of the present invention, which is a fourth embodiment of the present invention.

[0023] In the picture: 1. Foundation pit retaining piles; Top beam 2; Inclined pile 3, supporting inclined pile 3.1, top inclined pile 3.2; Servo loading device 4, jack 4.1, lower end plate 4.2, upper end plate 4.3, screw 4.4, threaded sleeve 4.5; 5 cement-soil mixing piles; Inclined pile deflection alarm device 6, base 6.1, inclined guide rod 6.2, floating pressure plate 6.3, alarm 6.4, compression spring 6.5, limit block 6.6, inclined pile mounting hole 6.7. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Specific Implementation Example 1, such as Figure 1 , Figure 2 As shown, an axial force servo-driven inclined pile support for foundation pit engineering includes foundation pit retaining piles 1, capping beams 2, inclined piles 3, and a servo loading device 4. The capping beams are installed on top of the foundation pit retaining piles and connect the tops of each foundation pit retaining pile into one unit.

[0025] The inclined pile 3 includes a supporting inclined pile 3.1 and a top inclined pile 3.2. The upper end of the top inclined pile is integrated with the capping beam, and the lower end of the top inclined pile slopes inward toward the pit. The supporting inclined pile is inserted into the soil of the pit. The upper end of the supporting inclined pile slopes toward the direction of the pit retaining piles, and the upper end of the supporting inclined pile faces the lower end of the top inclined pile. The supporting inclined pile and the top inclined pile have the same slope.

[0026] The servo loading device 4 includes a jack 4.1, an upper end plate 4.3, and a lower end plate 4.2. The upper end plate is fixed to the lower end of the top inclined pile, and the lower end plate is fixed to the upper end of the supporting inclined pile. The jack is located between the lower end of the top inclined pile and the upper end of the supporting inclined pile. The jack applies axial force along the inclined pile axis between the top inclined pile and the supporting inclined pile (i.e., the jack applies axial force along the inclined pile axis between the top inclined pile and the supporting inclined pile, thus separating the top inclined pile and the supporting inclined pile), thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile. In this embodiment, the inclined pile axis refers to the length direction of the inclined pile.

[0027] This embodiment utilizes a combination of retaining piles and inclined piles for support. After the inclined piles are constructed, the excavation of the foundation pit can be completed in one go, without interfering with the construction of the underground structure. This optimizes the construction process and shortens the construction cycle. More importantly, a servo loading device applies axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the foundation pit soil at the bottom of the supporting inclined pile. This proactively controls the foundation pit deformation and effectively avoids the problem of excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles. Furthermore, during the foundation pit construction process, the axial force can be increased by adjusting the jacks to actively control the foundation pit deformation, further effectively preventing the problem of excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles.

[0028] Specifically, such as Figure 1 , Figure 2 As shown, the supporting inclined piles are composed of lattice columns. Of course, the supporting inclined piles can also be composed of I-beams or H-beams.

[0029] The top inclined pile is a concrete pile. Of course, the top inclined pile can also be constructed of lattice columns, I-beams, or H-beams.

[0030] The jack is a hydraulic servo jack. Of course, the jack can also be a regular hydraulic jack or other types of jacks.

[0031] like Figure 1 , Figure 2 As shown, the servo loading device also includes an axial force locking device. The axial force locking device includes a screw 4.4 and a threaded sleeve 4.5 threadedly connected to the screw. The screw is a hollow screw. The axial direction of the screw is parallel to the axial direction of the inclined pile. The screw and the threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile. In this embodiment, the end of the screw is fixed to the lower end plate, and the end of the threaded sleeve abuts against the upper end plate. Thus, after the servo loading device applies axial force, the axial force applied by the servo loading device can be locked onto the inclined pile by rotating the threaded sleeve, which supports the screw and the threaded sleeve between the lower end of the top inclined pile and the upper end of the supporting inclined pile.

[0032] Specific Embodiment Two: A construction method for axial force servo inclined pile support in foundation pit engineering. The specific structure of the axial force servo inclined pile support in this method is the same as that in Specific Embodiment One.

[0033] A construction method for axial force servo inclined pile support in foundation pit engineering includes the following steps in sequence. First, construct retaining piles around the foundation pit.

[0034] Second, construct the inclined support piles, inserting them into the soil inside the foundation pit on the inner side of the retaining piles.

[0035] Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and reserve inclined pile inserts at the top inclined pile position. Part of the inclined pile inserts extend to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile.

[0036] Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device.

[0037] Fifth, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile; Next, rotate the threaded sleeve so that the screw and the threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile, locking the axial force applied by the servo loading device onto the inclined pile.

[0038] Sixth, continue excavating the soil downwards. A servo loading device is used to apply axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the soil at the bottom of the supporting inclined pile. This actively controls the deformation of the foundation pit, effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles. Simultaneously, during the foundation pit construction process, the axial force applied by increasing the adjusting jacks can be used to actively control the deformation of the foundation pit, further effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles.

[0039] Furthermore, in the sixth step, during the continued downward excavation of the soil, the deformation of the retaining piles is monitored. When the deformation of the top of the retaining piles towards the inside of the pit exceeds a set value, the jacks increase the axial force applied between the top inclined pile and the supporting inclined pile to control the deformation of the retaining piles.

[0040] Specific Embodiment 3: A construction method for axial force servo inclined pile support in foundation pit engineering. The specific structure of the axial force servo inclined pile support in this method is the same as that in Specific Embodiment 1.

[0041] A construction method for axial force servo inclined pile support in foundation pit engineering includes the following steps in sequence. First, construct retaining piles around the foundation pit.

[0042] Second, such as Figure 3 As shown, the construction support inclined piles are constructed by using a jet grouting machine to construct a cement-soil mixing pile 5 of a set height at a set depth position in the foundation pit soil. Next, before the cement-soil mixing pile solidifies, the lattice column is pressed into the foundation pit soil, and the lower end of the lattice column is inserted into the cement-soil mixing pile.

[0043] Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and reserve inclined pile inserts at the top inclined pile position. Part of the inclined pile inserts extend to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile.

[0044] Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device.

[0045] Fifth, after the cement-soil mixing pile and the top inclined pile have solidified, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile. Next, rotate the threaded sleeve so that the screw and the threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile, locking the axial force applied by the servo loading device onto the inclined pile.

[0046] Sixth, continue excavating downwards. A servo loading device applies axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the soil at the bottom of the supporting inclined pile. This actively controls the foundation pit deformation, effectively preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles, which weakens the inclined pile support effect. More importantly, since the lower end of the lattice column is inserted into the cement-soil mixing pile, the servo loading device applies axial force, which actively compresses the foundation pit soil at the pile bottom through the cement-soil mixing pile. This effectively improves the soil's support capacity for the inclined pile, further preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles. Furthermore, during foundation pit construction, the axial force can be increased by adjusting the jacks to actively control foundation pit deformation, further preventing excessive foundation pit deformation caused by the compression deformation of the soil at the bottom of the inclined piles, which weakens the inclined pile support effect.

[0047] Furthermore, in the sixth step, during the continued downward excavation of the soil, the deformation of the retaining piles is monitored. When the deformation of the top of the retaining piles towards the inside of the pit exceeds a set value, the jacks increase the axial force applied between the top inclined pile and the supporting inclined pile to control the deformation of the retaining piles.

[0048] Specific Embodiment Four: A construction method for axial force servo inclined pile support in foundation pit engineering. The specific structure of the axial force servo inclined pile support in this method is the same as that in Specific Embodiment One.

[0049] A construction method for axial force servo inclined pile support in foundation pit engineering includes the following steps in sequence. First, construct retaining piles around the foundation pit.

[0050] Second, the construction supports inclined piles, specifically... Install a tilt alarm device on top of the supporting inclined pile, such as Figure 5 As shown, the inclined pile deflection alarm device 6 includes a base 6.1, a floating pressure plate 6.3, a compression spring 6.5, and an alarm 6.4. The base has an inclined pile mounting hole 6.7 that mates with the inclined pile. The base is fixed to the top of the inclined pile; specifically, the top of the inclined pile is inserted into the inclined pile mounting hole to fix the base to the top of the inclined pile. An inclined guide rod 6.2 is provided on the base, extending axially along the inclined pile. The floating pressure plate has a guide hole that mates with the inclined guide rod. The inclined guide rod passes through the guide hole, and the floating pressure plate slides along the inclined guide rod. A limiting block 6.6 is provided at the end of the inclined guide rod, and the floating pressure plate is located between the limiting block and the base. The compression spring is sleeved on the inclined guide rod, supporting the base and the floating pressure plate, which presses against the limiting block under the action of the compression spring. The alarm is fixed to the base and located between the base and the floating pressure plate. The alarm is a push-button type.

[0051] like Figure 4 As shown, a jet grouting machine is used to construct inclined cement-soil mixing piles 5 within the foundation pit. The inclination angle of the cement-soil mixing piles is the same as the inclination angle of the supporting inclined piles. The cement-soil mixing piles extend to the ground surface, and their length is greater than or equal to the length of the supporting inclined piles.

[0052] Next, before the cement-soil mixing pile solidifies, the lattice column is pressed into the cement-soil mixing pile, specifically including the following steps: a. The press machine applies pressure to the lattice column through the floating pressure plate, pressing the lattice column into the cement-soil mixing pile. During this process, if the pressing direction of the lattice column is inconsistent with the inclination angle of the cement-soil mixing pile, the lower end of the lattice column will be inserted into the soil outside the cement-soil mixing pile. After the lower end of the lattice column is inserted into the soil outside the cement-soil mixing pile, the floating pressure plate will overcome the force of the compression spring and move down along the inclined guide rod. When the floating pressure plate touches the alarm, the alarm will sound. At this time, the press machine stops applying pressure, allowing the floating pressure plate to reset under the action of the compression spring and separate from the alarm. b) The operator adjusts the insertion angle of the lattice column to match the inclination angle of the cement-soil mixing pile. Then, return to step a until the lattice column is completely inserted into the cement-soil mixing pile. This ensures that the inclination angles of the lattice column and the cement-soil mixing pile are consistent, allowing the lattice column to be completely contained within the pile. This avoids the problem of a portion of the lattice column being inserted into the soil due to inconsistent inclination angles, which would prevent the lattice column and the cement-soil mixing pile from forming a cohesive unit and thus affect the support capacity of the inclined pile.

[0053] c. Remove the inclined pile deflection alarm device from the supporting inclined pile; Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and reserve inclined pile inserts at the top inclined pile position. Part of the inclined pile inserts extend to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile.

[0054] Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device.

[0055] Fifth, after the cement-soil mixing pile and the top inclined pile have solidified, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile. Next, rotate the threaded sleeve so that the screw and the threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile, locking the axial force applied by the servo loading device onto the inclined pile.

[0056] Sixth, continue excavating the soil downwards. A servo loading device applies axial force along the axis of the inclined piles between the top inclined pile and the supporting inclined pile, actively compressing the soil at the bottom of the supporting inclined pile. This actively controls the deformation of the foundation pit, effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles. More importantly, since the lattice column is inserted entirely into the cement-soil mixing pile, the servo loading device applies axial force, which actively compresses the soil at the bottom of the pile through the cement-soil mixing pile. This effectively improves the support capacity of the soil at the bottom of the pile for the inclined pile, further preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined pile. Simultaneously, the combination of cement-soil mixing piles and lattice columns further enhances the support capacity of the inclined piles. Furthermore, during the foundation pit construction process, the axial force can be increased by adjusting the jacks to actively control the deformation of the foundation pit, further effectively preventing excessive deformation due to compression deformation of the soil at the bottom of the inclined piles, which weakens the support effect of the inclined piles.

[0057] Furthermore, in the sixth step, during the continued downward excavation of the soil, the deformation of the retaining piles is monitored. When the deformation of the top of the retaining piles towards the inside of the pit exceeds a set value, the jacks increase the axial force applied between the top inclined pile and the supporting inclined pile to control the deformation of the retaining piles.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A servo-driven inclined pile support for foundation pit engineering, characterized in that, include: The foundation pit retaining piles are topped with capping beams; Inclined piles include supporting inclined piles and top inclined piles, wherein the upper end of the top inclined pile is integrated with the capping beam, and the lower end of the top inclined pile is inclined inward towards the pit. A tilting alarm device is installed at the top of the supporting inclined pile. The tilting alarm device includes: The base is fixed to the top of the supporting inclined pile, and an inclined guide rod is provided on it, which extends along the axial direction of the supporting inclined pile. The floating pressure plate slides along the inclined guide rod; Compression spring, supporting the base and floating pressure plate; The alarm is fixed to the base and located between the base and the floating pressure plate; The supporting inclined piles are inserted into the soil of the foundation pit. Specifically, there are inclined cement-soil mixing piles installed in the soil of the foundation pit. The supporting inclined piles are composed of lattice columns. During construction, a pressing machine is used to apply pressure to the lattice columns through floating pressure plates to press the lattice columns into the cement-soil mixing piles. After the lattice columns are pressed into the cement-soil mixing piles, the inclined pile deflection alarm device is removed. The upper end of the supporting inclined pile is inclined towards the direction of the foundation pit retaining piles, and the upper end of the supporting inclined pile is facing the lower end of the top inclined pile. The servo loading device includes a jack located between the lower end of the top inclined pile and the upper end of the supporting inclined pile. The jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile.

2. The axial force servo inclined pile support for foundation pit engineering according to claim 1, characterized in that, The servo loading device also includes an axial force locking device.

3. The axial force servo inclined pile support for foundation pit engineering according to claim 2, characterized in that, The axial force locking device includes a screw and a threaded sleeve that is threadedly connected to the screw. The screw and the threaded sleeve are supported between the lower end of the top inclined pile and the upper end of the supporting inclined pile.

4. The axial force servo inclined pile support for foundation pit engineering according to claim 3, characterized in that, The axial direction of the screw is parallel to the axial direction of the inclined pile.

5. The axial force servo inclined pile support for foundation pit engineering according to claim 1, 2, 3, or 4, characterized in that, The servo loading device also includes an upper end plate, which is fixed to the lower end of the top inclined pile.

6. The axial force servo inclined pile support for foundation pit engineering according to claim 5, characterized in that, The servo loading device also includes a lower end plate, which is fixed to the upper end of the supporting inclined pile.

7. The axial force servo inclined pile support for foundation pit engineering according to claim 1, 2, 3, or 4, characterized in that, The top inclined pile is a concrete pile.

8. The axial force servo inclined pile support for foundation pit engineering according to claim 1, 2, 3, or 4, characterized in that, The jack is a hydraulic servo jack.

9. A construction method for axial force servo inclined pile support in foundation pit engineering as described in any one of claims 1-8, characterized in that, The steps are as follows: First, construct retaining piles around the foundation pit; Second, construct inclined piles to support the construction. An inclined pile deflection alarm device is installed on the top of the supporting inclined pile. The inclined pile deflection alarm device includes: The base is fixed to the top of the supporting inclined pile, and the base is equipped with an inclined guide rod that extends along the axial direction of the supporting inclined pile. Floating pressure plate, the floating pressure plate slides along the inclined guide rod; Compression spring, between the compression spring support base and the floating pressure plate; An alarm is fixed to the base and located between the base and the floating pressure plate. A jet grouting machine is used to construct inclined cement-soil mixing piles within the foundation pit soil. Next, before the cement-soil mixing pile solidifies, the lattice column is pressed into the cement-soil mixing pile, specifically including the following steps: a. The press machine applies pressure to the lattice column through the floating pressure plate, pressing the lattice column into the cement-soil mixing pile. During this process, if the pressing direction of the lattice column is inconsistent with the inclination angle of the cement-soil mixing pile, the lower end of the lattice column will be inserted into the soil outside the cement-soil mixing pile. After the lower end of the lattice column is inserted into the soil outside the cement-soil mixing pile, the floating pressure plate will overcome the force of the compression spring and move down along the inclined guide rod. When the floating pressure plate touches the alarm, the alarm will sound. At this time, the press machine stops applying pressure, allowing the floating pressure plate to reset under the action of the compression spring and separate from the alarm. b. The operator adjusts the pressing angle of the lattice column to make the pressing angle of the lattice column consistent with the inclination angle of the cement-soil mixing pile. Then, return to step a until the lattice column is completely pressed into the cement-soil mixing pile. c. Remove the inclined pile deflection alarm device from the supporting inclined pile; Third, construct the capping beam. Cast the capping beam on top of the foundation pit retaining piles, and pre-reserve inclined pile reinforcement bars at the top inclined pile position. Part of the inclined pile reinforcement bars extends to the outside of the capping beam. Next, concrete is poured at the insertion point of the inclined pile to form the top inclined pile; Fourth, excavate the soil downwards within the retaining piles of the foundation pit until the top of the supporting inclined piles is exposed to a set length; then, install the servo loading device. Fifth, after the cement-soil mixing pile and the top inclined pile have solidified, the jack applies axial force along the axis of the inclined pile between the top inclined pile and the supporting inclined pile, thereby actively compressing the foundation pit soil at the bottom of the supporting inclined pile. Sixth, continue excavating the soil downwards.

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