Foundation pit underwater excavation temporary steel supporting system based on water injection and drainage control

Abstract

The invention discloses a foundation pit underwater excavation temporary steel support system based on water injection and drainage control, which adopts a steel support, first underwater liquid level meters arranged on the inner sides of the two ends of the steel support, a data acquisition instrument and a control system, two upper water injection holes are formed in the upper wall of the steel support in a bilateral symmetry mode, and two lower water injection holes are formed in the lower wall of the steel support. By opening and closing the upper water injection and drainage hole and the lower water injection and drainage hole of the steel support and monitoring the height change of the water level in the left side and the right side of the steel support through the first underwater liquid level meter, controllable sinking, stress balance and drainage adjustment of the steel support can be achieved; the problems of inconvenience in settlement adjustment, high construction risk, large peripheral disturbance and the like in the prior art are solved, so that the safety, the accuracy and the operation simplicity and convenience of underwater excavation construction of the foundation pit are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering construction support and underwater excavation technology, and specifically relates to a temporary steel support system for underwater excavation of foundation pits based on injection and drainage control. It is particularly suitable for foundation pit construction scenarios in densely populated urban areas, underground space renovation, and under high groundwater levels or underwater conditions. Background Technology

[0002] With the increasing urban renewal and utilization of underground space, excavation work in deep foundation pits, near water areas, and under high groundwater levels is becoming more frequent. Traditional temporary steel supports are mostly rigid, closed pipes, and settlement adjustment usually relies on mechanical hoisting, jacks, or replacement of support components. These processes are time-consuming, risky, and cause significant disturbance to surrounding structures and pipelines. Meanwhile, the drainage and water level control of underwater or high-water-level foundation pits significantly affect the stress state of the supports, but few existing technologies incorporate built-in drainage and injection regulation functions within the support structure. The lack of convenient and controllable settlement adjustment methods in existing technologies leads to inaccurate positioning and frequent adjustments during construction, increasing safety risks and extending the construction period. Summary of the Invention

[0003] The purpose of this invention is to provide a temporary steel support system for underwater excavation of foundation pits based on injection and drainage control. By opening and closing the injection and drainage holes at the top and bottom of the steel support, the controllable settlement, stress balance and drainage adjustment of the steel support can be achieved, solving the problems of inconvenient settlement adjustment, high construction risk and large surrounding disturbance in the prior art, thereby effectively improving the safety, accuracy and ease of operation of underwater excavation of foundation pits.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] A temporary steel support system for underwater excavation of foundation pits based on water injection and drainage control includes a steel support, a first underwater level gauge installed on the inner sides of both ends of the steel support, a data acquisition instrument, and a control system. The steel support is a hollow tube closed at both ends and is horizontally positioned. Two lifting rings for installing slings of a pile driver are symmetrically arranged on the upper surface of the steel support. Two upper water injection holes are symmetrically arranged on the upper wall of the steel support, and two lower water injection holes are provided on the lower wall of the steel support. The two upper and two lower water injection holes are arranged vertically corresponding to each other. The steel supports are identical in size and shape. A first ball valve switch is installed on the upper water inlet, and a second ball valve switch is installed in the lower water inlet. The first ball valve switch can open or close the corresponding upper water inlet, and the second ball valve switch can open or close the corresponding lower water inlet. When both upper and lower water inlets are closed, the steel support is in a sealed state. A first underwater level gauge can monitor the internal water level changes on both sides of the steel support. The first underwater level gauge is communicatively connected to a data acquisition instrument, which is communicatively connected to a control system. The first ball valve switch, the second ball valve switch, and the hoisting machine are all communicatively connected to and controlled by the control system.

[0006] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on water injection and drainage control, when the steel support is hoisted by the hoisting machine, the steel support is set horizontally, and the lower surface of the steel support is flush with the horizontal plane of the foundation pit. Two upper water injection holes are opened and two lower water injection holes are closed. Water is injected into the two upper water injection holes at the same flow rate, and the steel support slowly sinks. The internal water level changes on the left and right sides of the steel support are monitored in real time by two first underwater level gauges, and the data is sent to the control system via a data acquisition instrument. The control system controls the pile hoist to lower the hoisting cable accordingly based on the real-time monitoring data of the internal water level changes on the left and right sides of the steel support by the first underwater level gauges, so that the water level inside and outside the steel support is consistent, thereby keeping the hoisting force provided by the pile hoist equal to the self-weight of the steel support, until the steel support is completely submerged in water and filled with water.

[0007] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on water injection and drainage control, after the steel support is completely submerged in the water and filled with water, water injection into the two upper water injection holes is stopped, the two upper water injection holes are kept open, and the two lower water injection holes are opened. The steel support is slowly lowered by the pile driver until the steel support reaches the intended installation position, thus completing the installation of the steel support.

[0008] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, there are two first underwater level gauges, which are respectively installed on the bottom wall of the inner side of the left and right ends of the steel support.

[0009] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the first underwater level gauge is a differential pressure level gauge or a float level gauge.

[0010] Preferably, the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control also includes four second underwater level gauges. The four second underwater level gauges are respectively installed at the center of the front and rear side walls at the left and right ends of the steel support. The water level height at the left and right ends of the steel support in the foundation pit can be monitored through the second underwater level gauges.

[0011] Preferably, the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control also includes a third underwater level gauge. The third underwater level gauge is set at the same water level as the intended installation position of the steel support in the foundation pit, and the water level of the intended installation position of the steel support in the foundation pit can be obtained through the third underwater level gauge.

[0012] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, when the water level heights measured by the second and third underwater level gauges are the same, it indicates that the steel support has reached the intended installation position.

[0013] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the second underwater level gauge and the third underwater level gauge are hydrostatic level gauges.

[0014] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the second underwater level gauge, the first underwater level gauge, and the third underwater level gauge are connected to the data acquisition instrument via wired or wireless means, and the data acquisition instrument is connected to the control system via wired or wireless means.

[0015] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the control system controls the opening and closing of the first ball valve switch and the second ball valve switch respectively through relays.

[0016] As can be seen from the above-disclosed technical solutions, the beneficial effects of the present invention compared with the prior art are as follows:

[0017] This invention discloses a temporary steel support system for underwater excavation of foundation pits based on water injection and drainage control. The system comprises a steel support, a first underwater level gauge located on the inner sides of both ends of the steel support, a data acquisition instrument, and a control system. The steel support is a hollow tube closed at both ends and horizontally positioned. Two lifting rings for installing the slings of a pile driver are symmetrically arranged on the upper surface of the steel support. Two upper water injection holes are symmetrically arranged on the upper wall of the steel support, and two lower water injection holes are located on the lower wall of the steel support. The upper and lower water inlets are configured to correspond to each other, with the upper and lower water inlets having the same size and shape. The upper water inlet is equipped with a first ball valve switch, and the lower water inlet is equipped with a second ball valve switch. The first ball valve switch can open or close the corresponding upper water inlet, and the second ball valve switch can open or close the corresponding lower water inlet. When both upper and lower water inlets are closed, the steel support is in a sealed state. The first underwater level gauge is communicatively connected to the data acquisition instrument, which is communicatively connected to the control system. The first ball valve switch, the second ball valve switch, and the hoisting machine are all communicatively connected to and controlled by the control system. This invention enables controllable sinking, force balance, and drainage adjustment of the steel support by opening and closing the upper and lower drainage holes of the steel support and by monitoring the internal water level changes on both sides of the steel support through a first underwater level gauge. This solves the problems of inconvenient settlement adjustment, high construction risk, and large surrounding disturbance in the prior art, thereby effectively improving the safety, accuracy, and ease of operation of underwater excavation construction of foundation pits. Attached Figure Description

[0018] Figure 1 This is an elevation view of the steel support in the temporary steel support system for underwater excavation of foundation pits based on water injection and drainage control, as described in this invention.

[0019] Figure 2 This is a cross-sectional view of the steel support in the temporary steel support system for underwater excavation of foundation pits based on water injection and drainage control, as described in this invention.

[0020] Figure 3 This is a top view of the steel support in the temporary steel support system for underwater excavation of foundation pits based on water injection and drainage control, as described in this invention.

[0021] Figure 4 This is a structural diagram showing the lower surface of the steel support flush with the water level in the foundation pit.

[0022] Figure 5 This is a schematic diagram of the structure when the steel support is injected and sinks.

[0023] Figure 6 This is a schematic diagram of the structure when the steel support is completely submerged in water and then sinks after being filled with water.

[0024] Figure 7 This is a schematic diagram of the structure after the steel supports are installed.

[0025] In the diagram: 1-Steel support, 2-First ball valve switch, 3-Second ball valve switch, 4-Second underwater level gauge, 5-First underwater level gauge, 6-Lifting ring, 7-Third underwater level gauge, 8-Foundation pit, 9-Water injection pipe. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The technical content and features of the present invention will be described in detail below with reference to the listed embodiments and the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. For ease of description, the terms "upper" and "lower" used below are consistent with the upper and lower directions in the accompanying drawings, but this should not be construed as a limitation of the technical solution of the present invention.

[0027] Please see Figures 1 to 7This embodiment discloses a temporary steel support system for underwater excavation of foundation pits based on water injection and drainage control. It includes a steel support 1, a first underwater level gauge 5 located on the inner sides of both ends of the steel support 1, a data acquisition instrument, and a control system. The steel support 1 is a hollow tube closed at both ends. The steel support 1 is horizontally positioned. Two lifting rings 6 are provided on the upper surface of the steel support 1 for installing the slings of a pile driver (not shown). The two lifting rings 6 are symmetrically arranged on the upper surface of the steel support 1. Two upper water injection holes (not shown, but their positions are the same as the first ball valve switch) are opened on the upper wall of the steel support 1. The two upper water injection holes are symmetrically arranged on the upper wall of the steel support 1. Two lower water injection holes (not shown, but their positions are the same as the second ball valve switch) are opened on the lower wall of the steel support 1. The two upper water injection holes and the two lower water injection holes... The water inlets are arranged vertically and horizontally, with the upper and lower water inlets having the same size and shape. The lower water inlets are symmetrically arranged on the lower wall of the steel support 1, which can significantly reduce the eccentric force during drainage. The upper water inlet is equipped with a first ball valve switch 2, and the lower water inlet is equipped with a second ball valve switch 3. The first ball valve switch 2 can open or close the corresponding upper water inlet, and the second ball valve switch 3 can open or close the corresponding lower water inlet. When both upper and lower water inlets are closed, the steel support 1 is in a sealed state. The first underwater level gauge 5 is communicatively connected to a data acquisition instrument (not shown), and the data acquisition instrument is communicatively connected to a control system (not shown). The first ball valve switch 2, the second ball valve switch 3, and the hoisting machine are all communicatively connected to and controlled by the control system. This invention enables the controllable sinking, force balance, and drainage adjustment of the steel support 1 by opening and closing the upper and lower drainage holes of the steel support 1 and by monitoring the internal water level changes on the left and right sides of the steel support 1 through the first underwater level gauge 5. This solves the problems of inconvenient settlement adjustment, high construction risk, and large surrounding disturbance in the prior art, thereby effectively improving the safety, accuracy, and ease of operation of underwater excavation construction of the foundation pit 8.

[0028] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on water injection and drainage control, when the steel support 1 is hoisted by the hoisting machine, the steel support 1 is set horizontally, and the lower surface of the steel support 1 is flush with the horizontal plane of the foundation pit 8. Two upper water injection holes are opened and two lower water injection holes are closed. Water is injected into the two upper water injection holes at the same flow rate simultaneously. Water can be injected into the two upper water injection holes simultaneously at the same flow rate through the water injection pipe 9. The steel support 1 slowly sinks. The internal water level height changes on the left and right sides of the steel support 1 are monitored in real time by two first underwater level gauges 5, and the data is sent to the control system via the data acquisition instrument. The control system controls the pile hoist to lower the hoisting cable accordingly based on the data of the internal water level height changes on the left and right sides of the steel support 1 monitored in real time by the first underwater level gauges 5, so that the water level height inside and outside the steel support 1 is consistent, thereby keeping the hoisting force provided by the pile hoist equal to the self-weight of the steel support 1, until the steel support 1 is completely submerged in the water and the steel support 1 is filled with water. During the water injection process, the water level inside and outside the steel support 1 remains consistent. The lifting force of the pile driver is only equal to the weight of the steel support 1 itself, and the weight of the water inside cancels out the buoyancy. The water injection process is the process of the steel support 1 slowly sinking into the water. The surrounding water environment effectively reduces the swaying and displacement of the steel support 1 during the water injection process, reduces construction risks, and solves the problems of inconvenient settlement adjustment, high construction risks, and large surrounding disturbances in the existing technology. This further improves the safety, accuracy, and ease of operation of the underwater excavation construction of the foundation pit 8.

[0029] Preferably, in the aforementioned temporary steel support system for underwater excavation of the foundation pit based on water injection and drainage control, when the steel support 1 is completely submerged in the water and filled with water, there is no water pressure difference between the inside and outside of the steel support 1. Water injection into the two upper water injection holes is stopped, while the two upper water injection holes remain open. The two lower water injection holes are then opened, and the steel support 1 is slowly lowered using a pile driver until it reaches the intended installation position, thus completing the installation of the steel support 1. With no water pressure difference between the inside and outside of the steel support 1, and the corresponding upper and lower water injection holes open simultaneously, the steel support 1 can sink or float stably and accurately without being affected by buoyancy. This allows for controllable sinking, balanced stress, and drainage adjustment of the steel support 1, solving problems such as inconvenient settlement adjustment, high construction risk, and large surrounding disturbances in existing technologies. This further improves the safety, accuracy, and ease of operation of underwater excavation of the foundation pit 8.

[0030] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, there are two first underwater level gauges 5, which are respectively installed on the inner bottom walls of the left and right ends of the steel support 1. Alternatively, the first underwater level gauges 5 can also be installed on the inner surfaces of the two end walls of the steel support 1 via ropes.

[0031] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the first underwater level gauge 5 is a differential pressure level gauge or a float level gauge.

[0032] Preferably, the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control also includes four second underwater level gauges 4. The four second underwater level gauges 4 are respectively installed at the center of the front and rear side walls at the left and right ends of the steel support 1. The water level height at the left and right ends of the steel support 1 in the foundation pit 8 can be monitored through the second underwater level gauges 4.

[0033] Preferably, the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control also includes a third underwater level gauge 7. The third underwater level gauge 7 is set at the same water level as the intended installation position of the steel support 1 in the foundation pit 8. The water level of the intended installation position of the steel support 1 in the foundation pit 8 can be obtained through the third underwater level gauge 7.

[0034] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, when the water level heights measured by the second underwater level gauge 4 and the third underwater level gauge 7 are the same, it indicates that the steel support 1 has reached the intended installation position.

[0035] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the second underwater level gauge 4 and the third underwater level gauge 7 are hydrostatic level gauges.

[0036] Preferably, in the above-mentioned temporary steel support system for underwater excavation of foundation pit based on injection and drainage control, the second underwater level gauge 4, the first underwater level gauge 5, and the third underwater level gauge 7 are connected to the data acquisition instrument via wired or wireless means, and the data acquisition instrument is connected to the control system via wired or wireless means.

[0037] Preferably, in the aforementioned temporary steel support system for underwater excavation of foundation pits based on injection and drainage control, the control system controls the opening and closing of the first ball valve switch 2 and the second ball valve switch 3 via relays. The control system's remote control of the opening and closing of the first ball valve switch 2 and the second ball valve switch 3 via relays enables remote control of their on / off states. Closing the lower injection hole facilitates water injection into the steel support 1; opening the lower injection hole facilitates water drainage from the bottom of the steel support 1. The use of the first ball valve switch 2 and the second ball valve switch 3 effectively resists water pressure inside and outside the pipe wall; remote control of the first ball valve switch 2 and the second ball valve switch 3 via relays, as well as real-time control of the status of the steel support 1 and its internal water level, are achieved.

[0038] Preferably, in this embodiment, the steel support 1 is made of high-strength steel, possessing sufficient bending stiffness and compressive strength; and the steel support 1 has an internal vacuum, allowing for water injection. Furthermore, during processing, both the inner and outer surfaces of the steel support 1 are coated with a waterproof layer. Due to the internal vacuum of the steel support 1, water injection and drainage can be achieved, thereby ensuring precise and stable control of the sinking of the steel support 1 during the underwater excavation process of the foundation pit 8. Applying a waterproof layer to both the inner and outer surfaces of the steel support 1 greatly improves its underwater corrosion resistance and extends the reusable lifespan of this type of steel support 1.

[0039] Preferably, the steel lifting rings 6 are symmetrically arranged on the upper surface of the steel support 1, which can effectively reduce the eccentric force during the hoisting of the steel support 1 and improve the stability of the steel support 1 during the up and down hoisting.

[0040] Preferably, in this embodiment, four first underwater level gauges 5 are installed on the outer side of the pipe wall, symmetrically mounted on the four sides of the central axis of the steel support 1. The electrical signals of the first underwater level gauges 5 can be transmitted in real time to the data acquisition instrument via a wired connection, enabling real-time and accurate monitoring of the sinking depth of the steel support 1. The transmission line is connected to the ground data acquisition instrument via the sling of the steel support 1. The symmetrical arrangement of the first underwater level gauges 5 enables monitoring of the sinking position of the steel support 1 and assessment of whether the height of the left and right sides of the steel support 1 remains consistent; wired transmission ensures the stability and real-time performance of the water level signal.

[0041] Preferably, in this embodiment, two second underwater level gauges 4 are installed on the lower inner surface of the steel support 1, respectively located near the lower drainage hole of the steel support 1. The second underwater level gauges 4 are connected to an external data acquisition instrument via a wired connection (passing through the upper drainage hole); the second underwater level gauges 4 can monitor the changes in the internal water level of the steel support 1 in real time when water is injected.

[0042] Preferably, in this embodiment, a third underwater level gauge 7 is pre-installed at the same water level as the intended installation location of the steel support 1. The real-time data monitored by the third underwater level gauge 7 is transmitted to the data acquisition instrument via a wired connection. The hydraulic water level data at the intended installation location measured by the third underwater level gauge 7 can provide a real-time reference for the sinking target position of the steel support 1. The real-time hydraulic water level data at this location can effectively reduce the impact of water level fluctuations on the inaccuracy of the sinking position. At the same time, this method can also greatly reduce the workload and measurement difficulty of underwater measurement and positioning.

[0043] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A temporary steel support system for underwater excavation of a foundation pit based on injection-drainage control, characterized in that, The system includes a steel support, a first underwater level gauge located on the inner sides of both ends of the steel support, a data acquisition instrument, and a control system. The steel support is a hollow tube closed at both ends and is horizontally positioned. Two lifting rings for installing the slings of the pile driver are symmetrically arranged on the upper surface of the steel support. Two upper water injection holes are symmetrically arranged on the upper wall of the steel support, and two lower water injection holes are symmetrically arranged on the lower wall of the steel support. The two upper and two lower water injection holes are vertically aligned and are identical in size and shape. A first ball valve switch is provided on the upper water injection hole, and a second ball valve switch is provided in the lower water injection hole. The first ball valve switch can open or close the corresponding upper water injection hole, and the second ball valve switch can open or close the corresponding lower water injection hole. When both upper water injection holes and both lower water injection holes are closed, the steel support is in a sealed state. The change in the internal water level on the left and right sides of the steel support can be monitored by a first underwater level gauge. The first underwater level gauge is communicatively connected to a data acquisition instrument, and the data acquisition instrument is communicatively connected to a control system. The first ball valve switch, the second ball valve switch, and the hoisting machine are all communicatively connected to and controlled by the control system.

2. The temporary steel support system for underwater excavation of a foundation pit based on water drainage control according to claim 1, wherein, When hoisting the steel support using a hoisting machine, the steel support is positioned horizontally with its lower surface flush with the horizontal plane of the foundation pit. Two upper water injection holes are opened, and two lower water injection holes are closed. Water is simultaneously injected into the two upper water injection holes at the same flow rate, causing the steel support to slowly sink. Two first underwater level gauges monitor the changes in the internal water level on both sides of the steel support in real time, and the data is transmitted to the control system via a data acquisition device. Based on the real-time monitoring data of the internal water level changes on both sides of the steel support by the first underwater level gauges, the control system controls the hoisting machine to lower the slings accordingly, ensuring that the water level inside and outside the steel support remains consistent. This ensures that the lifting force provided by the hoisting machine is equal to the weight of the steel support, until the steel support is completely submerged and filled with water.

3. The temporary steel support system for the underwater excavation of a foundation pit based on the control of water drainage according to claim 1, characterized in that, Once the steel support is fully submerged and filled with water, stop injecting water into the two upper water injection holes, keep the two upper water injection holes open, and open the two lower water injection holes. Slowly lower the steel support using a pile driver until it reaches the intended installation position, thus completing the installation of the steel support.

4. The temporary steel support system for the underwater excavation of a foundation pit based on the control of water drainage according to claim 1, characterized in that, There are two first underwater level gauges, which are respectively installed on the bottom wall of the inner side of the left and right ends of the steel support.

5. The temporary steel support system for underwater excavation of foundation pits based on injection and drainage control as described in claim 1, characterized in that, The first underwater level gauge is either a differential pressure level gauge or a float level gauge.

6. The temporary steel support system for underwater excavation of foundation pits based on injection and drainage control as described in claim 1, characterized in that, It also includes four second underwater level gauges, which are respectively installed at the center of the front and rear side walls at both ends of the steel support. The second underwater level gauges can monitor the water level height at both ends of the steel support in the foundation pit.

7. The temporary steel support system for underwater excavation of foundation pits based on injection and drainage control as described in claim 3, characterized in that, It also includes a third underwater level gauge, which is installed at the same water level as the intended installation location of the steel support in the foundation pit. The third underwater level gauge can be used to obtain the water level of the intended installation location of the steel support in the foundation pit.

8. The temporary steel support system for underwater excavation of foundation pits based on injection and drainage control as described in claim 4, characterized in that, When the water level measured by the second and third underwater level gauges is the same, it indicates that the steel support has reached the intended installation position.

9. The temporary steel support system for underwater excavation of foundation pit based on injection and drainage control as described in claim 4, wherein the second underwater level gauge and the third underwater level gauge are hydrostatic level gauges.

10. The temporary steel support system for underwater excavation of foundation pits based on injection and drainage control as described in claim 5, characterized in that, The second, first, and third underwater level gauges are connected to the data acquisition unit via wired or wireless means, and the data acquisition unit is connected to the control system via wired or wireless means.

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