A support device and construction method for water-covered foundation pit excavation.

Abstract

This invention discloses a support device for excavating water-covered foundation pits, comprising an excavation mechanism and a support mechanism. The excavation mechanism includes: two sets of traveling tracks, a traveling beam, and horizontal grooves perpendicular to the direction of the traveling tracks on the top of the traveling beam; a support platform horizontally arranged on the traveling beam and slidingly engaged with the horizontal grooves; and a suction assembly arranged on the support platform. The support mechanism includes: two sets of vertical supports, each with vertical grooves on opposite sides, and multiple sets of retractable sliders spaced along the height direction within the vertical grooves; and multiple sets of internal support components arranged horizontally and vertically between the two sets of vertical supports, with both ends of each internal support component overlapping the retractable sliders at corresponding heights and capable of extension and retraction. This invention enables simultaneous excavation and mud cleaning, and simultaneous excavation and support erection, solving the difficult problem of water-covered excavation construction, improving efficiency, and enhancing construction safety.

Description

Technical Field

[0001] This invention relates to the field of foundation and substructure engineering technology, and more specifically to a support device and construction method for excavating foundation pits with water saturation. Background Technology

[0002] With the construction of numerous high-rise buildings and underground projects both domestically and internationally, the number of corresponding foundation pit projects has been increasing. At the same time, underground spaces and facilities for various purposes have also seen unprecedented development, including basements of high-rise buildings, subways, tunnels, underground commercial streets, and other forms.

[0003] Faced with engineering challenges such as water-covered excavation, the requirements for foundation pit engineering are becoming increasingly stringent. During the excavation process, the surrounding site will experience displacement due to the excavation action. Under the influence of this displacement field, buildings and structures around the foundation pit will deform and shift, reducing their safety and usability.

[0004] Traditional foundation pit support principles advocate for layered excavation and layered support, with excavation preceding support. In practice: first, the soil above the designed excavation surface is removed; then, the walers are installed on the exposed sides of the diaphragm wall above the excavation surface; finally, the horizontal support structure is installed. This construction sequence is repeated until the designed excavation bottom is reached. In this approach, the support process always lags behind the excavation. This inevitably leads to a displacement field developing in the unsupported excavation state before support is applied, potentially causing adverse effects on the surrounding environment. Furthermore, it may cause the diaphragm wall to tilt outwards or inwards.

[0005] In view of this, it is necessary to improve the excavation equipment and methods in the existing technology in order to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to disclose a support device and construction method for excavating foundation pits with water cover, so as to solve the problem of the underground continuous wall tilting outward or inward due to layered excavation and layered support, and excavation followed by support.

[0007] To achieve the above objectives, the present invention provides a support device for excavating a foundation pit covered with water, comprising an excavation mechanism and a support mechanism, wherein the excavation mechanism includes:

[0008] Two sets of walking tracks are located on both sides outside the foundation pit and are arranged in parallel opposite directions;

[0009] The traveling beam is horizontally erected above the foundation pit, and a traveling mechanism is arranged at the bottom end and slides in cooperation with the traveling track. The top of the traveling beam is provided with horizontal grooves that are perpendicular to the direction of the traveling track.

[0010] The support platform is horizontally arranged on the traveling beam and slides in conjunction with the horizontal groove;

[0011] A stirring and suction assembly is arranged on the support platform for excavating the soil in the foundation pit and cleaning up the mud.

[0012] The support mechanism includes:

[0013] Two sets of vertical supports are erected opposite each other in the trenches reserved inside the diaphragm wall and fixed to the diaphragm wall by fixing screws. Vertical sliding grooves are opened on the opposite sides of the two sets of vertical supports, and multiple sets of retractable sliding blocks are arranged at intervals along the height direction in the vertical sliding grooves.

[0014] Multiple sets of internal support components are arranged horizontally and spaced vertically between the two sets of vertical supports. The two ends of each set of internal support components overlap the corresponding height of the retractable slider and can extend and retract, providing lateral support for the diaphragm wall.

[0015] As a further improvement of the present invention, the agitation assembly includes:

[0016] The water outlet pipe is connected at one end to an external high-pressure water pump and at the other end to the bottom of the support platform, and is used to spray high-pressure water jets onto the excavated area.

[0017] The suction pipe is connected at one end to an external water pump and at the other end to the bottom of the support platform for suctioning mud from the pit.

[0018] The spiral agitator is rotatably arranged at the bottom of the support platform and is equipped with a drive motor for excavation work in the soil.

[0019] As a further improvement of the present invention, the bottom of the support platform is slidably engaged with the horizontal slide groove by ball bearings, the bottom ends of the traveling beam are provided with longitudinal slide grooves along the vertical direction of the horizontal slide groove, and the top of the traveling mechanism is slidably engaged with the longitudinal slide groove by ball bearings.

[0020] As a further improvement of the present invention, the vertical support is composed of multiple segments spliced ​​together, and adjacent segments are connected by bolts.

[0021] As a further improvement of the present invention, the vertical slide groove is a trapezoidal structure that is wider at the top and narrower at the bottom, and the opposite sides of the slide groove are provided with limit movable grooves along the vertical direction for the installation and positioning of the retractable slider.

[0022] The shrinking slider includes:

[0023] A fixed shaft has positioning connecting blocks at both ends connected by threads. The positioning connecting blocks slide with the limiting movable groove for positioning and installation.

[0024] Multiple sets of fan-shaped steel plates are arranged at intervals along the circumference at the top of the fixed shaft, and a pressure spring is connected between the tail ends of adjacent fan-shaped steel plates.

[0025] After the soil outside the shrinkage slider in the foundation pit is cleared, multiple sets of fan-shaped steel plates open and reset under the elastic force of the pressure spring, forming a support platform at the top for the inner support assembly to be connected.

[0026] As a further improvement of the present invention, the limiting movable groove is a trapezoidal structure that is narrow at the top and wide at the bottom, and the positioning connecting block of each group of shrinking sliders is also a trapezoidal structure, and the size decreases from top to bottom, so as to be able to fix and cooperate with the different heights of the limiting movable groove.

[0027] As a further improvement of the present invention, each set of the internal support components includes: a steel pipe support and separate hydraulic jacks arranged at one or both ends of the steel pipe support.

[0028] Among them, the two ends of the set of internal support components located at the top layer are positioned and cooperated with the limiting movable groove by setting wedge blocks to provide support force and axial tensile force for the diaphragm wall, so as to prevent the diaphragm wall from tilting outward or inward.

[0029] As a further improvement of the present invention, the top of the vertical support extends outward to form a horizontal connecting section on the diaphragm wall, and the vertical support is connected to the diaphragm wall by fixing screws.

[0030] This invention also discloses a construction method for excavating foundation pits with water embankment, comprising the following steps:

[0031] S1. When excavating trenches for diaphragm wall construction, a space for installing vertical supports is reserved on the inner side of the diaphragm wall, and wooden boards are placed inside to prevent grout from flowing in during diaphragm wall construction. After the diaphragm wall is formed, the wooden boards are removed, vertical supports are installed, and fixed to the diaphragm wall with fixing screws. The shrinking sliders are then placed horizontally in sequence.

[0032] S2, set up the excavation mechanism to excavate the foundation pit, fill the foundation pit with water through the agitation and suction component to ensure that the foundation pit is in a water-covered state, then treat the soil with mud through the agitation and suction component and remove the mud. After the soil around the uppermost shrinking slider in the foundation pit is cleaned, the shrinking slider automatically pops open to carry out the next support action.

[0033] S3, hoist the first set of internal support components to the top of the vertical support, set wedge blocks at both ends that can slide with the limiting movable groove, lower the first set of steel pipe supports to overlap the top of the shrink slider, at this time the wedge blocks can be positioned and engaged with the limiting movable groove, apply lateral axial force by controlling the separate hydraulic jack, and stop applying pressure when the corresponding pressure is reached;

[0034] S4. Repeat the excavation steps of step S2. When the excavation reaches the height of the second set of shrinking sliders, hoist the second set of steel pipes to the corresponding height and place them sideways on the top of the corresponding shrinking sliders. Then apply axial force. Stop applying pressure when the corresponding pressure is reached. Repeat this process in sequence.

[0035] S5, Pit bottom sealing: After the support installation is completed, underwater concrete is poured into the bottom of the pit to seal it.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] (1) A support device for excavating a water-covered foundation pit, comprising a traveling track, a traveling beam, a bearing platform, a stirring and suction component, and a support mechanism, enables water-covered excavation operations, allowing the excavation of the foundation pit to be carried out simultaneously with mud extraction and support erection, thereby improving construction efficiency, saving construction costs, and minimizing the impact on the surrounding environment of the foundation pit; through the flexible support of multiple sets of internal support components, it can provide lateral support force for the excavation of the diaphragm wall, wherein the two ends of the uppermost set of internal support components are designed with wedge blocks, which can cooperate with the limiting movable groove of the vertical support to provide support force and axial tensile force for the diaphragm wall, thereby preventing the diaphragm wall from tilting outward or inward, improving the safety of construction and the quality of the project.

[0038] (2) A construction method for excavating a foundation pit with water cover, wherein the foundation pit excavation and support erection are carried out simultaneously, which improves the excavation efficiency. The method adopts underwater excavation without lowering the water level, which has little impact on the surrounding environment. The water pressure in the foundation pit can provide support for the foundation pit. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the construction structure of a support device and construction method for water-covered excavation of foundation pits according to the present invention.

[0040] Figure 2 This is a schematic diagram illustrating the cooperation between the shrinkage slider and the internal support assembly in the foundation pit, as well as the cooperation between the vertical support and the underground continuous wall, in a support device and construction method for water-covered foundation pit excavation according to the present invention.

[0041] Figure 3 This is a schematic diagram of the distribution of shrinkage sliders in the vertical support in a support device and construction method for excavating a water-covered foundation pit according to the present invention, and the vertical sliding groove is also shown in the figure.

[0042] Figure 4 This is a three-dimensional structural diagram of the shrinkage slider in a support device and construction method for water-covered excavation of foundation pits according to the present invention.

[0043] Figure 5 This is a three-dimensional structural diagram of the top-level internal support component in a support device and construction method for excavating a foundation pit with water cover, according to the present invention.

[0044] In the diagram: 1. Agitator assembly; 2. Support platform; 3. Ball bearings; 4. Traveling beam; 5. Traveling mechanism; 6. Vertical support; 7. Retractable slider; 8. Fixing screw; 9. Steel pipe support; 10. Separable hydraulic jack; 11. Water outlet pipe; 12. Suction pipe; 13. Spiral agitator head; 51. Traveling track; 71. Fixed shaft; 72. Fan-shaped steel plate; 101. Wedge block. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0046] Please refer to Figures 1 to 5 The present invention illustrates a specific embodiment of a support device and construction method for excavating a foundation pit covered with water.

[0047] A support device for excavating a water-covered foundation pit includes an excavation mechanism and a support mechanism. The excavation mechanism includes: two sets of traveling tracks 51, located on both sides outside the foundation pit and arranged parallel to each other; a traveling beam 4, horizontally erected above the foundation pit, with a traveling mechanism 5 at its bottom end that slides in cooperation with the traveling tracks 51; and a horizontal chute perpendicular to the direction of the traveling tracks 51, located on the top of the traveling beam 4; a support platform 2, horizontally arranged on the traveling beam 4 and sliding in cooperation with the horizontal chute; and a suction assembly 1, arranged on the support platform 2, used for excavating the soil in the foundation pit and cleaning the mud. It should be understood that multiple suction assemblies 1 can be freely selected and arranged on the support platform 2 according to the actual project requirements. The bottom of the support platform 2 slides in cooperation with the horizontal chute via ball bearings 3. The bottom ends of the traveling beam 4 have longitudinal chutes perpendicular to the horizontal chute, and the top of the traveling mechanism 5 slides in cooperation with the longitudinal chute via ball bearings 3.

[0048] It should be understood that the walking mechanism 5 includes walking support legs and walking wheels, which walk along the extension direction of the walking track 51 and are used for coarse adjustment of the excavation position. Through the cooperative design of the ball bearings 3 with the horizontal chute and the longitudinal chute, the working position of the agitator 1 is changed to achieve fine adjustment of the excavation position.

[0049] The support mechanism includes two sets of vertical supports 6, which are erected opposite each other in the trench reserved inside the diaphragm wall and fixed to the diaphragm wall by fixing screws 8. The top of the vertical supports 6 extends outward to the outside of the diaphragm wall to form a horizontal connecting section. The vertical supports 6 are connected to the diaphragm wall by fixing screws 8. The vertical supports 6 are composed of multiple segments spliced ​​together, and adjacent segments are bolted together. The height of the vertical supports 6 is adjusted according to the actual excavation depth.

[0050] Vertical grooves are provided on opposite sides of the two sets of vertical supports 6, and multiple sets of retractable sliders 7 are arranged at intervals along the height direction in the vertical grooves; multiple sets of internal support components are arranged horizontally between the two sets of vertical supports 6 at intervals along the vertical direction, and the two ends of each set of internal support components overlap on the retractable sliders 7 at the corresponding height and can extend and retract, providing lateral support for the diaphragm wall.

[0051] The agitation and suction assembly 1 includes: a water outlet pipe 11, one end of which is connected to an external high-pressure water pump, and the other end is arranged at the bottom of the support platform 2, for spraying high-pressure water flow to the excavation area, thereby facilitating soil excavation; a suction pipe 12, one end of which is connected to an external water pump, and the other end is arranged at the bottom of the support platform 2, for suctioning mud in the foundation pit; and a spiral agitator head 13, which is rotatably arranged at the bottom of the support platform 2 and equipped with a drive motor for soil excavation and advancement.

[0052] The retractable slider 7 includes: a fixed shaft 71 with positioning connecting blocks threaded to both ends, the positioning connecting blocks slidingly engaging with the limiting movable groove for positioning and installation; multiple sets of fan-shaped steel plates 72, spaced circumferentially at the top of the fixed shaft 71, with pressure springs connecting the tails of adjacent fan-shaped steel plates 72; after the soil outside the retractable slider 7 in the foundation pit is cleared, the multiple sets of fan-shaped steel plates 72 open and reset under the elastic force of the pressure springs, forming a support platform at the top for the internal support components to be connected. Furthermore, the vertical chute is a trapezoidal structure wider at the top and narrower at the bottom, and limiting movable grooves are vertically provided on opposite sides of the chute for the installation and positioning of the retractable slider 7; the limiting movable groove is a trapezoidal structure narrower at the top and wider at the bottom, and the positioning connecting blocks of each set of retractable sliders 7 are trapezoidal structures, decreasing in size from top to bottom to be fixedly engaged with different heights of the limiting movable groove; the two end faces of the positioning connecting blocks are beveled.

[0053] Each set of internal support components includes: a steel pipe support 9 and separate hydraulic jacks 10 arranged at one or both ends of the steel pipe support 9; wherein, the two ends of the set of internal support components located at the top layer are positioned and cooperated with the wedge blocks 101 and the limiting movable groove to provide support force and axial tensile force for the diaphragm wall, so as to prevent the diaphragm wall from tilting outward or inward.

[0054] This invention also discloses a construction method for excavating foundation pits with water embankment, comprising the following steps:

[0055] S1. During the excavation of the trench for the construction of the diaphragm wall, a space for the installation of the vertical support 6 is reserved on the inner side of the diaphragm wall, and wooden boards are placed inside to prevent grout from flowing in during the diaphragm wall construction. After the diaphragm wall is formed, the wooden boards are removed, the vertical support 6 is installed, and it is fixed to the diaphragm wall with fixing screws 8. The shrinking sliders 7 are then placed horizontally in sequence. S2. The excavation mechanism is set up to excavate the foundation pit. Water is injected into the foundation pit through the agitator 1 to ensure that the foundation pit is in a water-covered state. Then, the soil is treated with mud by the agitator 1 and the mud is removed. After the soil around the uppermost shrinking slider 7 in the foundation pit is cleared, the shrinking slider 7 automatically pops open to proceed to the next support action. S3. The first set of internal support components is hoisted. The steel pipes are transported to the top of the vertical support 6, and wedge blocks 101 that can slide and engage with the limiting movable grooves are set at both ends. The first set of steel pipe supports 9 are lowered to overlap the top of the retractable slider 7. At this time, the wedge blocks 101 can be positioned and engaged with the limiting movable grooves. The lateral axial force is applied by controlling the separate hydraulic jacks 10. The pressure is stopped when the corresponding pressure is reached. S4, the excavation steps of step S2 are repeated. When the excavation reaches the height of the second set of retractable sliders 7, the second set of steel pipes is hoisted to the corresponding height and placed laterally on the top of the corresponding retractable slider 7. The axial force is applied again. The pressure is stopped when the corresponding pressure is reached. This step is repeated in sequence. S5, the bottom of the foundation pit is sealed. After the support is installed, underwater concrete is poured into the bottom of the foundation pit to seal the bottom.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A support apparatus for water-covered excavation of a foundation pit, comprising an excavation mechanism and a support mechanism, characterized in that, The excavation mechanism includes: Two sets of walking tracks are located on both sides outside the foundation pit and are arranged in parallel opposite directions; The traveling beam is horizontally erected above the foundation pit, and a traveling mechanism is arranged at the bottom end and slides in cooperation with the traveling track. The top of the traveling beam is provided with horizontal grooves that are perpendicular to the direction of the traveling track. The support platform is horizontally arranged on the traveling beam and slides in conjunction with the horizontal groove; A stirring and suction assembly is arranged on the support platform for excavating the soil in the foundation pit and cleaning up the mud. The support mechanism includes: Two sets of vertical supports are erected opposite each other in the trenches reserved inside the diaphragm wall and fixed to the diaphragm wall by fixing screws. Vertical sliding grooves are opened on the opposite sides of the two sets of vertical supports, and multiple sets of retractable sliding blocks are arranged at intervals along the height direction in the vertical sliding grooves. Multiple sets of internal support components are arranged horizontally and spaced vertically between two sets of vertical supports. The two ends of each set of internal support components overlap the corresponding height of the retractable slider and can extend and retract, providing lateral support for the underground continuous wall. The vertical slide groove is a trapezoidal structure that is wider at the top and narrower at the bottom, and the opposite sides of the slide groove are provided with limit movable grooves along the vertical direction for the installation and positioning of the retractable slider. The shrinking slider includes: A fixed shaft has positioning connecting blocks at both ends connected by threads. The positioning connecting blocks slide with the limiting movable groove for positioning and installation. Multiple sets of fan-shaped steel plates are arranged at intervals along the circumference at the top of the fixed shaft, and a pressure spring is connected between the tail ends of adjacent fan-shaped steel plates. After the soil outside the shrinkage slider in the foundation pit is cleared, multiple sets of fan-shaped steel plates open and reset under the elastic force of the pressure spring, forming a support platform at the top for the inner support assembly to be connected.

2. The supporting equipment for water-covered excavation of foundation pit according to claim 1, characterized in that, The agitation assembly includes: The water outlet pipe is connected at one end to an external high-pressure water pump and at the other end to the bottom of the support platform, and is used to spray high-pressure water jets onto the excavated area. The suction pipe is connected at one end to an external water pump and at the other end to the bottom of the support platform for suctioning mud from the pit. The spiral agitator is rotatably arranged at the bottom of the support platform and is equipped with a drive motor for excavation work in the soil.

3. The supporting equipment for water-covered excavation of foundation pit according to claim 1, characterized in that, The bottom of the support platform is slidably engaged with the horizontal slide groove via ball bearings. The bottom ends of the traveling beam are provided with longitudinal slide grooves along the vertical direction of the horizontal slide groove, and the top of the traveling mechanism is slidably engaged with the longitudinal slide groove via ball bearings.

4. The support equipment for water-covered foundation pit excavation according to claim 1, characterized in that, The vertical support is composed of multiple segments, with adjacent segments connected by bolts.

5. A support device for excavating a foundation pit covered with water according to claim 1, characterized in that, The limiting movable groove is a trapezoidal structure that is narrower at the top and wider at the bottom. The positioning connecting block of each set of shrinkable sliders is also a trapezoidal structure, and its size decreases from top to bottom, so as to be able to be fixedly matched with the different heights of the limiting movable groove.

6. A support device for excavating a foundation pit covered with water according to claim 5, characterized in that, Each set of internal support components includes: a steel pipe support and separate hydraulic jacks arranged at one or both ends of the steel pipe support; Among them, the two ends of the set of internal support components located at the top layer are positioned and cooperated with the limiting movable groove by setting wedge blocks to provide support force and axial tensile force for the diaphragm wall, so as to prevent the diaphragm wall from tilting outward or inward.

7. A support device for excavating a foundation pit covered with water according to claim 1, characterized in that, The top of the vertical support extends outward from the diaphragm wall to form a horizontal connecting section, and the vertical support is connected to the diaphragm wall by fixing screws.

8. A construction method for excavating a foundation pit covered with water, based on the support equipment for excavating a foundation pit covered with water as described in claim 6, characterized in that, Includes the following steps: S1. When excavating trenches for diaphragm wall construction, a space for installing vertical supports is reserved on the inner side of the diaphragm wall, and wooden boards are placed inside to prevent grout from flowing in during diaphragm wall construction. After the diaphragm wall is formed, the wooden boards are removed, vertical supports are installed, and fixed to the diaphragm wall with fixing screws. The shrinking sliders are then placed horizontally in sequence. S2, set up the excavation mechanism to excavate the foundation pit, fill the foundation pit with water through the agitation and suction component to ensure that the foundation pit is in a water-covered state, then treat the soil with mud through the agitation and suction component and remove the mud. After the soil around the uppermost shrinking slider in the foundation pit is cleaned, the shrinking slider automatically pops open to carry out the next support action. S3, hoist the first set of internal support components to the top of the vertical support, set wedge blocks at both ends that can slide with the limiting movable groove, lower the first set of steel pipe supports to overlap the top of the shrink slider, at this time the wedge blocks can be positioned and engaged with the limiting movable groove, apply lateral axial force by controlling the separate hydraulic jack, and stop applying pressure when the corresponding pressure is reached; S4. Repeat the excavation steps of step S2. When the excavation reaches the height of the second set of shrinking sliders, hoist the second set of steel pipes to the corresponding height and place them sideways on the top of the corresponding shrinking sliders. Then apply axial force. Stop applying pressure when the corresponding pressure is reached. Repeat this process in sequence. S5, Pit bottom sealing: After the support installation is completed, underwater concrete is poured into the bottom of the pit to seal it.

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