Mechanical excavation construction and intelligent monitoring method for foundation pit of ultra-deep steel pipe pile cofferdam

Abstract

The invention relates to the technical field of cofferdam foundation pit construction, in particular to an ultra-deep steel pipe pile cofferdam foundation pit mechanical excavation construction and intelligent monitoring method which comprises the steps that water pumping is conducted after a first-layer inner support in a cofferdam is installed; when the water level drops to a preset height away from the bottom surface of the support, installing the next layer of inner support; sequentially and circularly dewatering and installing an inner support until water is completely pumped out, and then dredging the foundation pit; the mounting qualification of the inner support above the soil is judged according to the cofferdam deformation characteristic value; when the installation of the inner support is qualified, judging whether the stability of the inner support meets a preset standard or not according to the stress standard deviation of the inner support; continuing to mount the inner support of the next layer based on the condition that the stability of the inner support meets the preset standard; and dredging, monitoring and inner support mounting are sequentially and circularly carried out until the whole foundation pit is excavated, so that the construction efficiency of the cofferdam foundation pit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cofferdam foundation pit construction, and in particular to a mechanical excavation construction and intelligent monitoring method for an ultra-deep steel pipe pile cofferdam foundation pit. Background Art

[0002] A steel pipe pile cofferdam is a cofferdam structure composed primarily of steel pipe piles, supplemented by other materials. It is primarily used to isolate the construction area, preventing water from entering the area and ensuring smooth construction. Excavation of the foundation pit lays the foundation for subsequent foundation pile construction. During excavation, key factors such as excavation depth, slope, and support measures must be carefully controlled to prevent cofferdam collapse and groundwater infiltration.

[0003] Chinese patent publication number: CN109837908B discloses a foundation pit construction method, comprising the following steps: constructing a vertical retaining structure around the foundation pit; installing horizontal steel supports on the retaining structure; excavating earth to the bottom of the foundation pit; constructing the main structure's exterior wall, attaching an exterior wall reinforcement frame to the horizontal steel supports, and pouring concrete on the exterior wall reinforcement frame to form the main structure's exterior wall; and cutting and disassembling the portion of the main structure's exterior wall from the horizontal steel supports. This invention replaces the concrete supports used in the prior art with steel supports. Furthermore, during the construction of the main structure's exterior wall, the exterior wall reinforcement frame is directly connected to the horizontal steel supports, and concrete is poured on the exterior wall reinforcement frame to form the main structure's exterior wall. After the concrete structure reaches sufficient strength, the steel structure outside the main structure's exterior wall is cut and disassembled. However, the prior art suffers from the following problems: The prior art lacks a monitoring method for foundation pit construction, resulting in low efficiency due to the inability to timely control the construction. Summary of the Invention

[0004] To this end, the present invention provides a method for mechanical excavation construction and intelligent monitoring of an ultra-deep steel pipe pile cofferdam foundation pit to overcome the problems in the prior art.

[0005] To achieve the above-mentioned object, the present invention provides a method for mechanical excavation construction and intelligent monitoring of an ultra-deep steel pipe pile cofferdam foundation pit, comprising: Pumping out water after the first-floor internal supports within the cofferdam are installed; When the water level drops to a preset height from the bottom of the support, install the next layer of inner support; The water is circulated and lowered in sequence, and the internal supports are installed until the water is pumped out and then the foundation pit is dredged; Determine the eligibility of the internal support installation above the soil based on the cofferdam deformation characteristic value; When the internal support installation fails to meet the standards, the monitoring frequency of the cofferdam deformation should be adjusted according to the water level rise rate outside the cofferdam, or the strategy for reinforcing the cofferdam should be determined according to the horizontal deformation rate of the cofferdam; When the internal support is installed properly, determine whether the stability of the internal support meets the preset standards based on the stress standard deviation of the internal support; Continue installing the next layer of internal support based on the condition that the stability of the internal support meets the preset standards; The dredging, monitoring and installation of internal supports are repeated in sequence until the entire foundation pit excavation is completed.

[0006] Furthermore, under the condition that the cofferdam deformation characteristic value is less than a first preset deformation characteristic value, the inner support is judged to be installed qualified, and whether the stability of the inner support meets the preset standard is judged based on the stress standard deviation of the inner support.

[0007] Furthermore, the process of determining the unqualified installation of the internal support according to the cofferdam deformation characteristic value includes: If the cofferdam deformation characteristic value is greater than or equal to the first preset deformation characteristic value, the internal support installation is determined to be unqualified, and, If the cofferdam deformation characteristic value is greater than or equal to the first preset deformation characteristic value and less than the second preset deformation characteristic value, the internal support installation is determined to be unqualified, and the monitoring frequency of the cofferdam deformation is adjusted according to the water level rising rate outside the cofferdam; If the cofferdam deformation characteristic value is greater than or equal to the second preset deformation characteristic value, it is determined that the internal support installation is unqualified, and a strategy for reinforcing the cofferdam is determined based on the horizontal deformation rate of the cofferdam.

[0008] Furthermore, the cofferdam deformation characteristic value is determined by the horizontal displacement value and the vertical displacement value of the cofferdam.

[0009] Furthermore, under the condition that the stress standard deviation is less than the preset standard deviation, it is determined that the stability of the internal support meets the preset standard, and the installation of the next layer of internal support is continued.

[0010] Furthermore, when the stress standard deviation is greater than or equal to the preset standard deviation, it is determined that the stability of the internal support does not meet the preset standard, and the number of supporting steel pipes is increased according to the difference between the stress value of the internal support and the preset stress value.

[0011] Furthermore, the monitoring frequency of cofferdam deformation is positively correlated with the rate of water level rise outside the cofferdam.

[0012] Furthermore, under the condition that the horizontal deformation rate of the cofferdam is less than the preset deformation rate, the strategy for reinforcing the cofferdam is determined to be adding an inner support layer.

[0013] Furthermore, when the horizontal deformation rate of the cofferdam is greater than or equal to the preset deformation rate, the strategy for reinforcing the cofferdam is determined to be pumping water into the foundation pit, and a new construction plan is formulated.

[0014] Furthermore, different adjustment methods are provided for the number of supporting steel pipes, and each method has a different adjustment range for the number of supporting steel pipes.

[0015] Compared with the prior art, the beneficial effect of the present invention is that the present invention dynamically adjusts the construction plan by determining the eligibility and stability of the internal support installation, improves the construction efficiency through intelligent monitoring, and ensures the safety of the construction.

[0016] Furthermore, the present invention adopts a cyclic construction method of layered pumping or dredging and installation of internal supports to ensure that the cofferdam is in a stable state after each layer of support is installed.

[0017] Furthermore, the present invention introduces a cofferdam deformation characteristic value, which is calculated by monitoring the horizontal and vertical displacement values of the cofferdam. The eligibility of the internal support installation is determined based on the cofferdam deformation characteristic value, and when it is unqualified, the monitoring frequency of the cofferdam deformation is adjusted according to the water level rising rate outside the cofferdam, or the strategy for reinforcing the cofferdam is determined based on the horizontal deformation rate of the cofferdam, so as to avoid structural risks caused by deformation or excessive stress.

[0018] Furthermore, the present invention determines whether the stability of the internal support meets the preset standard based on the stress standard deviation of the internal support. When it does not meet the preset standard, the number of supporting steel pipes in each layer is increased according to the difference between the average stress value of each layer of internal support and the preset stress value to ensure the stability of the cofferdam.

[0019] Furthermore, the present invention determines a strategy for reinforcing the cofferdam based on the horizontal deformation rate of the cofferdam, including adding an inner support layer, pumping water into the foundation pit and re-formulating a construction plan to flexibly respond to complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of a method for mechanical excavation construction and intelligent monitoring of an ultra-deep steel pipe pile cofferdam foundation pit according to an embodiment of the present invention; Figure 2 A flow chart showing the eligibility of internal support installation according to an embodiment of the present invention; Figure 3 A flow chart showing determination of internal support stability according to an embodiment of the present invention; Figure 4 A flow chart of a strategy for determining a cofferdam reinforcement method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0022] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0023] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0024] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0025] See also Figures 1 to 4 As shown, they are respectively a flow chart of the mechanical excavation construction and intelligent monitoring method of the ultra-deep steel pipe pile cofferdam foundation pit according to an embodiment of the present invention; a flow chart of determining the eligibility of the internal support installation according to an embodiment of the present invention; a flow chart of determining the stability of the internal support according to an embodiment of the present invention; and a flow chart of determining the strategy for reinforcing the cofferdam according to an embodiment of the present invention.

[0026] The mechanical excavation construction and intelligent monitoring method for an ultra-deep steel pipe pile cofferdam foundation pit according to an embodiment of the present invention includes: Step S1, pumping out water after the first-layer internal support installation is completed within the cofferdam; Step S2: When the water level drops to a preset height of 0.5 m from the bottom surface of the support, install the next layer of inner support; Step S3, cyclically dewatering and installing internal supports until the water is drained and then dredging the foundation pit is carried out; Step S4, determining the eligibility of the internal support installation above the soil based on the cofferdam deformation characteristic value; Step S5: When the internal support installation fails to meet the standards, the monitoring frequency of the cofferdam deformation is adjusted according to the water level rising rate outside the cofferdam, or a strategy for reinforcing the cofferdam is determined according to the horizontal deformation rate of the cofferdam; Step S6: When the inner support is installed properly, determine whether the stability of the inner support meets the preset standard based on the stress standard deviation of the inner support; Step S7: continuing the installation of the next layer of inner supports based on the condition that the inner support stability meets the preset standard; Step S8, dredging, monitoring, and installing internal supports are repeated in sequence until the entire foundation pit excavation is completed.

[0027] In the embodiment of the present invention, the preset height is set to 0.5 m, but the above value is not limited thereto, and those skilled in the art can adjust the value according to actual needs.

[0028] In this embodiment of the present invention, the inner support layer consists of corbels, perimeter purlins, and supporting steel pipes. The corbels are constructed of No. 10 channel steel and are spaced 3.0 meters apart along the perimeter purlins. The perimeter purlins are constructed of 3I56a I-beams. On one side, the I-beam seams are welded continuously and intermittently, with welds spaced every 2 meters and a length of 10 cm. On the other side, 1 cm thick gusset plates are welded, spaced every 2 meters.

[0029] Specifically, the installation of the purlin includes: marking the horizontal position of the purlin on the steel pipe pile after the cofferdam is closed; welding the steel support corbels to the steel pipe piles as the support system for the purlin installation; and using a crawler crane to lift the assembled and connected purlin steel sections onto the support corbels, placing them close to the steel pipe piles and welding them to them.

[0030] Specifically, when there is a gap between the purlin and the steel sheet pile, a small steel plate or steel section is added between the two for support connection, and arc welding is used for welding.

[0031] Specifically, the installation of internal supports includes: measuring the installation position of the support on the purlin, and accurately measuring the net distance between the purlins at both ends of each support, cutting the support according to the net distance, and cutting the steel pipe support into tongue and groove at both ends. Use a crawler crane to lift the support to the corresponding position for installation, directly arc welding the purlin and the support end to make it firm, and welding the top surface of the purlin and the support with connecting steel plates. Finally, install the triangular support at the corner of the cofferdam.

[0032] In the embodiment of the present invention, excavation is carried out using a long-arm excavator, a telescopic-arm excavator, and a hydraulic grab. For places that cannot be excavated by the long-arm excavator and the hydraulic grab, such as the corners of the cofferdam support, a crawler crane can be used to lift the micro excavator into the foundation pit for excavation. The excavated silt, silt sand, and clay are directly loaded onto trucks and transported by dump trucks to designated locations for drying and recycling.

[0033] Specifically, the first-floor internal supports are installed 0.5 m above the horizontal plane.

[0034] Specifically, in step S3, dredging is started after the water is drained to the same level as the mud surface, wherein a centrifugal pump is used to pump the water in the cofferdam out of the cofferdam.

[0035] Specifically, if individual lock buckles are found to be leaking during or after pumping out the cofferdam, divers can be sent into the water to check the location of the leak and perform water-stopping treatment according to the actual situation. Geotextile or foam glue can be used to fill the CO lock buckle bite position for blocking. If the lock buckle leaks significantly or there are many leaks that affect the excavation construction in the cofferdam, pumping should be stopped and water should be allowed to flow back into the cofferdam. After re-performing water-stopping treatment, pumping construction can be resumed.

[0036] Specifically, during the excavation process of the foundation pit, the bottom elevation of the center of the foundation pit is always kept slightly lower than the elevation of the surrounding areas of the foundation pit. There is no specific limit on the height difference. This setting facilitates the collection of groundwater in the foundation pit.

[0037] Specifically, the groundwater in the foundation pit is pumped out of the foundation pit using a submersible pump.

[0038] Specifically, under the condition that the cofferdam deformation characteristic value is less than the first preset deformation characteristic value 0.8, the internal support installation is determined to be qualified, and whether the stability of the internal support meets the preset standard is determined based on the stress standard deviation of the internal support.

[0039] Specifically, the process of determining the unqualified installation of internal supports based on the cofferdam deformation characteristic value includes: If the cofferdam deformation characteristic value is greater than or equal to the first preset deformation characteristic value, the internal support installation is determined to be unqualified, and, If the cofferdam deformation characteristic value is greater than or equal to the first preset deformation characteristic value and less than the second preset deformation characteristic value of 0.88, the internal support installation is determined to be unqualified, and the monitoring frequency of the cofferdam deformation is adjusted according to the water level rising rate outside the cofferdam; If the cofferdam deformation characteristic value is greater than or equal to the second preset deformation characteristic value, it is determined that the internal support installation is unqualified, and a strategy for reinforcing the cofferdam is determined based on the horizontal deformation rate of the cofferdam.

[0040] In the embodiment of the present invention, the first preset deformation characteristic value is 0.8, and the second preset deformation characteristic value is 0.88, but the above values are not limited thereto, and those skilled in the art may adjust the values according to actual needs.

[0041] Specifically, the cofferdam deformation characteristic value is determined by the horizontal displacement value and the vertical displacement value of the cofferdam, and is calculated by the following formula:

[0042] Among them, Q is the cofferdam deformation characteristic value, α is the first evaluation value, which is set to 0.65, X is the horizontal displacement value, X0 is the horizontal displacement threshold, and X0 is set to 40 mm; β is the second evaluation value, which is set to 0.35, Y is the vertical displacement value, Y0 is the vertical displacement threshold, and Y0 is set to 20 mm.

[0043] Specifically, the horizontal displacement value is the average value of the horizontal displacements measured at each horizontal displacement observation point of the cofferdam, and the vertical displacement value is the average value of the horizontal displacements measured at each horizontal displacement observation point of the cofferdam.

[0044] Specifically, horizontal displacement observation points are set at the midpoint of each side of the top surface of the rectangular cofferdam steel pipe pile, and at the middle position of the steel pipe pile body between each two adjacent layers of internal support vertically downward from the midpoint position; vertical displacement observation points are set at the four corners of the top surface of the rectangular cofferdam steel pipe pile, the midpoint of each side, and the center of the first layer of internal support.

[0045] Specifically, horizontal displacements are monitored using a total station, and deep horizontal displacements are monitored using an inclinometer.

[0046] Specifically, vertical displacement is monitored using a level.

[0047] Specifically, under the condition that the stress standard deviation is less than the preset standard deviation of 5.72, it is determined that the stability of the internal support meets the preset standard, and the installation of the next layer of internal support is continued.

[0048] Specifically, three stress monitoring points are arranged on each layer of internal support, and stress plates are attached to the inner support steel pipes of the cofferdam, and the stress changes of the inner support steel pipes are monitored by stress meters. The internal support stress can also be measured by installing stress gauges. The stress gauges use steel string strain gauges, which are connected to the inner support of the cofferdam by welding, and the stress values are read in real time through digital terminals.

[0049] In the embodiment of the present invention, the preset standard deviation is 5.72, but the above value is not limited thereto, and those skilled in the art can adjust the value according to actual needs.

[0050] Specifically, when the stress standard deviation is greater than or equal to the preset standard deviation, it is determined that the stability of the internal support does not meet the preset standard, and the number of supporting steel pipes in each layer is increased according to the difference between the average stress value of each layer of internal support and the preset stress value.

[0051] Specifically, the monitoring frequency of cofferdam deformation is positively correlated with the rate of water level rise outside the cofferdam, where If the water level rising rate is less than the first preset rising rate of 0.3 m / h, the monitoring frequency of the cofferdam deformation is adjusted to the corresponding value using the first frequency adjustment coefficient 1.01; If the water level rising rate is greater than or equal to the first preset rising rate and less than the second preset rising rate of 0.5 m / h, the monitoring frequency of the cofferdam deformation is adjusted to the corresponding value using the second frequency adjustment coefficient 1.03; If the water level rising rate is greater than or equal to the second preset rising rate, the monitoring frequency of the cofferdam deformation is adjusted to a corresponding value using a third frequency adjustment coefficient of 1.05.

[0052] In the embodiment of the present invention, the first preset rising rate is 0.3 m / h, and the second preset rising rate is 0.5 m / h, but the above values are not limited thereto. Those skilled in the art can adjust the values according to actual needs.

[0053] Specifically, the water level rising rate is obtained by monitoring a float-type water level gauge.

[0054] Specifically, under the condition that the horizontal deformation rate of the cofferdam is less than the preset deformation rate of 0.5%, the strategy for reinforcing the cofferdam is to add an internal support layer.

[0055] Specifically, the horizontal deformation rate is the ratio of the real-time area of the cofferdam top to the original area.

[0056] Specifically, the preset deformation rate is 0.5%, but the above value is not limited thereto, and those skilled in the art can adjust the value according to actual needs.

[0057] Specifically, the location where the inner support layer is added should be where the deformation is larger. There is no specific limit on the location and number of additional layers, as long as it ensures that the deformation rate of the cofferdam no longer increases.

[0058] Specifically, when the horizontal deformation rate of the cofferdam is greater than or equal to the preset deformation rate, the strategy for reinforcing the cofferdam is determined to be pumping water into the foundation pit, and a new construction plan is formulated.

[0059] Specifically, there is no specific limit on the amount of water pumped into the foundation pit, and it only needs to reduce the internal and external pressure difference of the cofferdam to a safe range.

[0060] Specifically, different adjustment methods are provided for the number of supporting steel pipes, and each method has a different adjustment range for the number of supporting steel pipes. If the stress difference is less than the preset stress difference of 5 MPa, the number of supporting steel pipes is adjusted to the corresponding value using the first quantity adjustment coefficient of 1.25; If the stress difference is greater than or equal to the preset stress difference, the number of supporting steel pipes is adjusted to the corresponding value using the second quantity adjustment coefficient of 1.5; The stress difference is the difference between the average stress value of the support in each layer and the preset stress value.

[0061] Specifically, if the quantity adjustment coefficient multiplied by the number of supporting steel pipes is a non-integer, it will be rounded up.

[0062] Specifically, the installation position of the support steel pipe is not specifically limited, and the support steel pipe can be added at the position with the largest stress value according to the actual stress value of the internal support.

[0063] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0064] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit, characterized in that: include: Pumping out water after the first-floor internal supports within the cofferdam are installed; When the water level drops to a preset height from the bottom of the support, install the next layer of inner support; The water is circulated and lowered in sequence, and the internal supports are installed until the water is pumped out and then the foundation pit is dredged; Determine the eligibility of the internal support installation above the soil based on the cofferdam deformation characteristic value; When the internal support installation fails, the frequency of monitoring the cofferdam deformation is adjusted according to the rate of water level rise outside the cofferdam, or the strategy for reinforcing the cofferdam is determined based on the horizontal deformation rate of the cofferdam, where the strategy includes adding an internal support layer and pumping water into the foundation pit; When the internal support is installed properly, determine whether the stability of the internal support meets the preset standards based on the stress standard deviation of the internal support; Continue installing the next layer of internal support based on the condition that the stability of the internal support meets the preset standards; The dredging, monitoring and installation of internal supports are repeated in sequence until the entire foundation pit excavation is completed.

2. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 1 is characterized in that: Under the condition that the cofferdam deformation characteristic value is less than the first preset deformation characteristic value, the inner support is judged to be installed qualified, and whether the stability of the inner support meets the preset standard is judged based on the stress standard deviation of the inner support.

3. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 2 is characterized in that: The process of determining the unqualified installation of internal supports based on the cofferdam deformation characteristic value includes: If the cofferdam deformation characteristic value is greater than or equal to the first preset deformation characteristic value, the internal support installation is determined to be unqualified, and, If the cofferdam deformation characteristic value is greater than or equal to the first preset deformation characteristic value and less than the second preset deformation characteristic value, the internal support installation is determined to be unqualified, and the monitoring frequency of the cofferdam deformation is adjusted according to the water level rising rate outside the cofferdam; If the cofferdam deformation characteristic value is greater than or equal to the second preset deformation characteristic value, it is determined that the internal support installation is unqualified, and a strategy for reinforcing the cofferdam is determined based on the horizontal deformation rate of the cofferdam.

4. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 3 is characterized in that: The cofferdam deformation characteristic value is determined by the horizontal displacement value and the vertical displacement value of the cofferdam.

5. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 4 is characterized in that: Under the condition that the stress standard deviation is less than the preset standard deviation, the stability of the internal support is determined to meet the preset standard, and the installation of the next layer of internal support is continued.

6. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 5 is characterized in that: When the stress standard deviation is greater than or equal to the preset standard deviation, it is determined that the stability of the internal support does not meet the preset standard, and the number of supporting steel pipes in each layer is increased according to the difference between the average stress value of each layer of internal support and the preset stress value.

7. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 6 is characterized in that: The monitoring frequency of cofferdam deformation is positively correlated with the rate of water level rise outside the cofferdam.

8. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 7 is characterized in that: Under the condition that the horizontal deformation rate of the cofferdam is less than the preset deformation rate, the strategy for reinforcing the cofferdam is to add an inner support layer.

9. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 8, characterized in that: When the horizontal deformation rate of the cofferdam is greater than or equal to the preset deformation rate, the strategy for reinforcing the cofferdam is determined to be pumping water into the foundation pit, and a new construction plan is formulated.

10. The method for mechanical excavation construction and intelligent monitoring of ultra-deep steel pipe pile cofferdam foundation pit according to claim 9, characterized in that: There are different adjustment methods for the number of supporting steel pipes, and each method has a different adjustment range for the number of supporting steel pipes.

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