Circular foundation pit excavation and pouring method

Abstract

The application discloses a foundation pit excavation and pouring method for a circular ground-connected wall, and full coverage of a foundation pit operation surface is realized by using a rotatable gantry truss; hoisting devices are arranged on the gantry truss, so that the hoisting devices can be walked to any position in the foundation pit to hoist earthwork in cooperation with the gantry truss, then the hoisting devices are lifted and run to the top of an earthwork vehicle outside the foundation pit to unload earthwork, after the unloading is completed, the hoisting devices are run into the foundation pit again to hoist earthwork, the method provided by the application can realize earth unloading operation at any position in the foundation pit, compared with a traditional earth unloading mode, the whole earth unloading process is safe, efficient and economical, in addition, after the foundation pit is excavated, a concrete conveying pipe can be arranged on the gantry truss to be used for large-volume filling core concrete distribution and pouring of the foundation pit, so that investment is further saved and the pouring construction difficulty of the large-volume filling core concrete is reduced.

Description

[0001] The present application relates to the field of bridge construction, in particular to a circular diaphragm wall foundation pit excavation and pouring method.

[0002] Anchorage facilities are a general term for anchor block foundations (including various forms such as enlarged foundations, underground continuous walls, caisson foundations, pile foundations, etc.), anchor blocks, main cable anchoring systems, and protective structures. It is a huge component that fixes the end of the main cable and prevents it from moving. It is the anchoring structure of the main cable of a suspension bridge. The tension in the main cable is transmitted to the foundation through the anchorage, and it is a force component that connects the anchor cable to the bridge. Its function is to hold the load-bearing suspension bridge.

[0003] A large foundation pit needs to be excavated for a gravity type anchorage of a suspension bridge. In order to prevent the risk of the pit collapsing due to the radial force on the side of the pit, a concrete wall needs to be built around the foundation, which is a diaphragm wall, and then excavation can be carried out in the foundation of the diaphragm wall.

[0004] The circular diaphragm wall foundation pit of a gravity type anchorage of a suspension bridge generally has the problems of large area, great depth, large excavation volume, low construction efficiency, and high cost. The traditional foundation pit excavation method uses a crawler crane and a tower crane to cooperate with a bucket to excavate in an island type layer by layer. That is, the soil around the circular foundation is excavated first, and then the soil in the center is excavated. After excavating one layer, the next layer is excavated. The soil around the pit is excavated by a excavator, and then a crawler crane or a scaffold is used to remove the soil. The soil in the center is excavated by a excavator, and then a tower crane or a crawler crane is used to remove the soil. The construction process is as follows: ① The excavator in the foundation pit transports and loads the excavated soil to the bucket; ② The crawler crane or the tower crane hoists the bucket, turns a certain angle, and then unloads it to a certain position outside the foundation pit, and then a excavator or a loader is used to load the soil into a truck and transport it away; ③ After the soil is unloaded, the crawler crane or the tower crane turns a certain angle and hoists the empty bucket to the excavating operation position in the foundation pit, and then the next soil excavation, transportation, and loading are carried out.

[0005] The above-mentioned traditional excavation and soil removal method has the following disadvantages or defects:

[0006] (1) Due to the lifting weight and lifting distance limitations of the crawler crane and the tower crane, the excavator often needs to turn the soil to a certain position in the foundation pit before loading the soil into the bucket, which reduces the efficiency of soil removal and restricts the construction period and cost of the anchorage;

[0007] ​​(2) Because the corresponding lifting capacity of the tower crane or the crawler crane is different at different lifting distances, the position of the bucket in the foundation pit and the weight of the soil in the bucket need to be strictly controlled, and the unit weight and water content of different soil layers are different, which will bring some uncertain risks to the weight control of the bucket. In addition, the gravity acceleration caused by the too fast lifting speed of the hook will also cause the increase of the lifting weight and the overload risk. Therefore, the traditional excavation and soil removal method requires high responsibility, experience and concentration of the command and driving personnel, and any mistake will cause safety accidents such as equipment overturning;

[0008] (3) Although the use of cantilever scaffold for soil removal can easily control the position of the bucket and is not very sensitive to the weight, it brings the problem that the earthwork in the foundation pit needs to be transported multiple times to be loaded into the hopper, increasing the earthwork transportation cost in the pit;

[0009] (4) When the crawler crane is used for soil removal, if the angle of the crane arm is too steep during unloading, there is a risk of overturning;

[0010] (5) When multiple tower cranes are used to cover the foundation pit, there are interference and collision risks between the tower cranes;

[0011] (6) The ground loading link is increased, the work efficiency is reduced, and the cost is increased;

[0012] In order to conveniently and quickly excavate and remove soil, greatly improve the soil removal efficiency, shorten the construction period and reduce the cost, the applicant develops a new technical scheme.

SUMMARY

[0013] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a circular diaphragm wall foundation pit excavation and pouring method, which adopts the technical scheme of:

[0014] A circular diaphragm wall foundation pit excavation and pouring method, comprising the steps of:

[0015] S1, a circular foundation is demarcated according to the construction requirements;

[0016] S2, a diaphragm wall is arranged on the outer edge of the circumference of the circular foundation;

[0017] S3, the center of the foundation is defined as the operation center, and the distance from the center of the foundation to the diaphragm wall is defined as the operation radius;

[0018] S4, at least one portal truss is arranged directly above the foundation, and the length of the portal truss is not less than the operation radius, the first end of the portal truss is close to the operation center, and the last end of the portal truss exceeds the diaphragm wall;

[0019] S5, a plurality of hoisting devices are installed on the portal truss, the hoisting devices can move back and forth between the first end and the last end of the portal truss, and can rise and fall in height distance;

[0020] S6, the gantry truss can rotate around the operation center as the rotation axis, and the rotation track of one round rotation can cover the circular foundation;

[0021] S7, the excavator enters the foundation pit for excavation;

[0022] S8, the gantry truss can rotate to any angle, the hoisting device can move to any place on the gantry truss, the hoisting device can walk, descend to any position in the foundation pit, hoist the earthwork, and ascend, move to the end of the gantry truss, run to the top of the earthwork truck outside the foundation, and unload the earthwork into the earthwork truck; after unloading, it is empty to the next hoisting earthwork operation in the foundation pit;

[0023] S9, according to the construction requirements, the earthwork is excavated, hoisted and unloaded, and a circular foundation pit is excavated in the circular foundation;

[0024] S10, a concrete conveying pipe is installed on the gantry truss, and a plurality of unloading outlets are arranged on the gantry truss, a concrete pumping device is arranged outside the foundation and connected with the concrete conveying pipe, and the concrete is pumped and poured into the circular foundation pit through the concrete pumping device, the concrete conveying pipe and the unloading outlet; the gantry truss rotates according to the construction requirements for pouring;

[0025] S11, after the pouring is completed, the gantry truss and the hoisting device are removed.

[0026] In a further improved scheme, a central support hinge device is arranged at the operation center, and the leading end of the gantry truss is fixed to the central support hinge device, and the central support hinge device can drive the gantry truss to rotate circumferentially.

[0027] In a further improved scheme, when hoisting the earthwork, the earthwork is loaded and unloaded by connecting a soil box on the hoisting device.

[0028] In a further improved scheme, in step S9, the excavation operation progresses from the outer side close to the diaphragm wall to the inner side close to the operation center, and excavates layer by layer from high to low.

[0029] In a further improved scheme, in step S8, a hydraulic grab can be connected to the hoisting device for synchronous excavation.

[0030] In a further improved scheme, in step S10, a plurality of pump pipes are arranged at the unloading outlet, and the upper and lower pump pipes are detachably connected.

[0031] In a further improved scheme, in step S10, a vibration type concrete vibrator is hoisted on the hoisting device, and the vibration type concrete vibrator works synchronously to vibrate and consolidate the concrete in the foundation pit when the concrete is poured into the circular foundation pit.

[0032] In a further improved scheme, in step S10, the concrete is poured into the foundation pit through the concrete delivery pipe and the discharge outlet, and a pump is arranged outside the foundation pit to pour the concrete into the foundation pit simultaneously.

[0033] In a further improved scheme, in step S10, the pouring structure can be adjusted by adjusting the opening or closing of any discharge outlet, and the cushion layer, the bottom plate, the anchoring body filling core concrete body, and the anchoring body erosion-resistant peripheral concrete body are formed by pouring in the foundation pit.

[0034] Compared with the prior art, the method has the advantages that: the method is specially used for the earth excavation, slag discharge, and pouring of a circular diaphragm wall foundation pit, the movable gantry truss is used to realize the full coverage of the foundation pit operation surface, the lifting device is arranged on the gantry truss, the lifting device and the gantry truss can be moved to any position in the foundation to lift the earthwork, then the earthwork is lifted and moved to the top of the earthwork vehicle (also called a dump truck) outside the foundation to unload the earthwork, after the unloading is completed, the lifting device is moved into the foundation again to lift the earthwork, the method can realize the earth excavation at any position in the foundation pit, and compared with the traditional slag discharge method, the whole earth excavation process is safe, efficient, and economical, in addition, after the foundation pit is excavated, the concrete delivery pipe can be arranged on the gantry truss to distribute and pour the super-large volume filling core concrete in the foundation pit, and the investment is further saved and the pouring construction difficulty of the super-large volume filling core concrete is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0036] Figure 1 The foundation pit excavation structure in the embodiment of the present application is shown in Figure 1 ;

[0037] Figure 2 The foundation pit excavation structure in the embodiment of the present application is shown in Figure 2 ;

[0038] Figure 3 The foundation pit excavation structure in the embodiment of the present application is shown in Figure 3 ;

[0039] Figure 4 The foundation pit pouring structure in the embodiment of the present application is shown in Figure 1 ;

[0040] Figure 2 The foundation pit pouring structure in the embodiment of the present application is shown in Figure 6 ;

[0041] Figure 3 The foundation pit pouring structure in the embodiment of the present application is shown in Figures 1 to 6 .

[0042] Explanation of main element symbols:

[0043] 10, foundation; 20, diaphragm wall; 30, gantry truss; 40, hoisting device; 50, concrete delivery pipe; 60, central support hinge device; 70, soil removal box; 80, pump pipe; 90, vibration type concrete vibrator; 100, aerial pump; 110, ground pump; 120, cushion; 130, bottom plate; 140, anchoring body filled concrete; 150, anchoring body erosion-resistant peripheral concrete.

DETAILED DESCRIPTION

[0044] This part will describe the specific embodiments of the present application in detail, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with graphics, so that people can intuitively and visually understand each technical feature and the overall technical solution of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0045] In the description of the present application, the meaning of multiple is more than two, greater than, less than, more than, etc. is not included in the number, above, below, within, etc. is included in the number. If it is described as first, second, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0046] In the description of the present application, it is necessary to understand that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0047] In the present application, unless otherwise explicitly limited, the words "set", "install", "connect" and the like should be broadly understood, for example, they can be directly connected, or indirectly connected through an intermediate medium; can be fixedly connected, or can be detachably connected, or can be integrally formed; can be mechanically connected; can be the internal connection of two elements or the interaction relationship of two elements. The person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0048] The present application provides a circular diaphragm wall foundation pit excavation and pouring method, comprising the steps of:

[0049] S1, a circular foundation 10 is demarcated according to the construction requirements;

[0050] S2, a diaphragm wall 20 is provided on the outer edge of the circumference of the circular foundation 10;

[0051] S3, define the center of the foundation 10 as the working center, and define the distance from the center of the foundation 10 to the diaphragm wall 20 as the working radius;

[0052] S4, at least one portal truss 30 is arranged above the foundation 10, and the length of the portal truss 30 is not less than the working radius, the leading end of the portal truss 30 is close to the working center, and the trailing end of the portal truss 30 exceeds the diaphragm wall 20;

[0053] S5, a plurality of hoisting devices 40 are installed on the portal truss 30, the hoisting devices 40 can move back and forth between the leading end and the trailing end of the portal truss 30, and can be raised and lowered in the height distance;

[0054] S6, the portal truss 30 can rotate around the working center as the rotation axis, and the rotation track of one rotation can cover the circular foundation 10;

[0055] S7, the excavator enters the foundation 10 to excavate;

[0056] S8, the portal truss 30 can rotate to any angle, the hoisting device 40 can move to any place on the portal truss 30, the hoisting device 40 can walk and descend to any position in the foundation 10 to hoist the earthwork, and then rise and move to the trailing end of the portal truss 30, run to the top of the earthwork truck outside the foundation 10, and unload the earthwork into the earthwork truck; after unloading, it is empty to the next hoisting earthwork operation in the foundation 10;

[0057] S9, according to the construction requirements, excavate, hoist and unload the earthwork to excavate a circular foundation pit in the circular foundation 10;

[0058] S10, a concrete delivery pipe 50 is installed on the portal truss 30, a plurality of unloading outlets are arranged on the portal truss 30, a concrete pumping device is arranged outside the foundation 10 and connected with the concrete delivery pipe 50, and the concrete is pumped and poured into the circular foundation pit through the concrete pumping device, the concrete delivery pipe 50 and the unloading outlet; the portal truss 30 rotates according to the construction requirements for rotary pouring;

[0059] S11, after the pouring is completed, the portal truss 30 and the hoisting device 40 are removed.

[0060] In the present application, steps S1-S2 are the preliminary work before the foundation pit excavation, steps S3-S9 are the foundation pit excavation process, and steps S10-S11 are the foundation pit pouring process. The present application proposes a special earth excavation, slagging and pouring method for circular diaphragm wall 20 foundation pit, which covers the circular foundation 10 within the rotation radius of the rotatable portal truss 30, realizes full coverage of the foundation pit working surface, and realizes the earth excavation, slagging and pouring of the circular diaphragm wall 20 foundation pit in the form of portal truss 30 rotation and hoisting device 40 movement. Figures 1 to 6In the illustrated embodiment, two pairs of symmetrically arranged double gantry trusses are arranged in a cross shape, spanning the foundation 10 in diameter. Lifting equipment 40 is arranged on the gantry truss 30, so that the lifting equipment 40, in conjunction with the gantry truss 30, can travel to any position within the foundation 10 to lift earthwork. Then, it is lifted and moved to the top of a dump truck (also called a dump truck) outside the foundation 10 to unload the earthwork. After unloading, the lifting equipment 40 moves back into the foundation 10 to lift earthwork again. The excavation operation proceeds from the outside of the diaphragm wall 20 to the inside of the work center, excavating layer by layer from high to low. After the earthwork in one area is excavated, the gantry truss 30 is rotated at a certain angle to excavate the earthwork in the next area, until the earthwork in the current layer is excavated, and then the next layer of earthwork is excavated. When lifting earthwork, the earthwork is loaded and unloaded by connecting a soil loading box 70 to the lifting equipment 40. The method provided by this invention can realize soil removal operations at any point within the foundation pit area. Traditional soil removal methods require numerous soil removal hoisting devices arranged at certain intervals around the foundation pit, multiple excavators inside the pit, and specialized loading equipment outside the pit. This results in significant interference and safety risks such as overloading and exceeding distance limits during equipment transfer or operation. Compared to traditional slag removal methods, this method eliminates the need for secondary transportation of soil within the foundation pit and loading of soil onto trucks on the shore, greatly improving construction efficiency and saving on machinery rental and driver labor costs. Furthermore, most of the soil removal equipment can be reused in subsequent similar projects, reducing costs. This method reduces the initial investment cost and offers certain economic and safety advantages. The entire excavation process is safe, efficient, and economical. Moreover, the construction equipment, such as the gantry truss 30 and hoisting equipment 40, is relatively simple compared to crawler cranes and tower cranes. This reduces the safety management tasks of the construction equipment and makes safety risks easier to control. In addition, after the foundation pit is excavated, a concrete delivery pipe 50 can be installed on the gantry truss 30. By connecting the concrete delivery pipe 50 to the ground pump 110 outside the foundation pit, it can be used for the placement and pouring of ultra-large volume core-filling concrete in the foundation pit, further saving investment and reducing the difficulty of pouring ultra-large volume core-filling concrete.

[0061] In an embodiment, such as Figure 4 As shown, a central support hinge device 60 is arranged at the work center, and the first end of the gantry truss 30 is fixed to the central support hinge device 60. The central support hinge device 60 can drive the gantry truss 30 to rotate in a circle, providing support for the gantry truss 30. Multiple rotating gantry trusses 30 can be arranged to work simultaneously, reducing the number of equipment sets and management difficulties. Moreover, it can be used for multiple purposes, providing concrete pumping and material placement channels during the later core filling concrete construction, improving work efficiency and reducing costs.

[0062] In the embodiment, the hydraulic grab can be connected on the hoisting device 40 for synchronous excavation. After the gantry truss 30 carries the hydraulic grab to the predetermined position, the hydraulic grab can be started to grab the earthwork, and then the earthwork can be directly transported out. The method has the advantages of large amount of excavation at one time, integrated excavation, transportation and loading, simple and fast operation, etc. Compared with the traditional excavation of foundation pit, the method does not need to carry out the secondary or multiple in-pit transportation of the earthwork of the foundation pit, and does not need the loading equipment outside the pit. When the soil in the pit is the silt type soft soil which cannot bear the load of the excavator, the advantages are more obvious.

[0063] In the embodiment, as shown in Figure 5 、 5 , in step S10, a plurality of pump pipes 80 are arranged at the discharge outlet, and the upper and lower pump pipes 80 are detachably connected. During the placement and pouring process, the pump pipes 80 can be removed according to the height of the foundation pit.

[0064] In the embodiment, as shown in Figure 5 、 6 , in step S10, a vibration type concrete vibrator 90 is hoisted on the hoisting device 40. When the concrete is poured into the circular foundation pit, the vibration type concrete vibrator 90 works synchronously to vibrate and compact the concrete in the foundation pit. During the placement and pouring process, the concrete is vibrated and compacted, which further saves the investment and reduces the difficulty of the pouring and vibrating construction of the large volume of core concrete.

[0065] In the embodiment, as shown in Figure 5 、 6 , in step S10, when the concrete is poured through the concrete conveying pipe 50 and the discharge outlet, a ground pump 100 is arranged outside the foundation pit to synchronously pour the concrete into the foundation pit, so as to fill the gap of the placement and pouring of the discharge outlet of the concrete conveying pipe 50.

[0066] In the embodiment, as shown in ​ 、 6 , in step S10, the opening or closing of any discharge outlet can be adjusted to adjust the pouring structure, so as to form the cushion 120, the bottom plate 130, the anchoring body core concrete body 140 and the anchoring body erosion-resistant peripheral concrete body 150 in the foundation pit.

[0067] Although the present application is described in detail with reference to the above embodiments, it is obvious to those skilled in the art from the disclosure that various changes or modifications can be made to the present application without departing from the principles and spirit of the application defined in the claims. Therefore, the detailed description of the embodiments of the present disclosure is only used for explanation, but not for limitation of the present application, and the protection scope is defined by the content of the claims.

Claims

1. A method for excavating and pouring a circular diaphragm wall foundation pit, characterized in that, The method comprises the steps of: S1, defining a circular foundation (10) according to construction requirements; S2, arranging a diaphragm wall (20) on the outer edge of the circumference of the circular foundation (10); S3, defining the center of the foundation (10) as a work center and the distance from the center of the foundation (10) to the diaphragm wall (20) as a work radius; S4, arranging at least one portal truss (30) above the foundation (10), and the length of the portal truss (30) is not less than the work radius, the first end of the portal truss (30) is close to the work center, and the last end of the portal truss (30) exceeds the diaphragm wall (20); S5, installing a plurality of hoisting devices (40) on the portal truss (30), the hoisting devices (40) can move back and forth between the first end and the last end of the portal truss (30) and can be raised and lowered in height; S6, the portal truss (30) can rotate around the work center as the rotation axis, and the rotation track of one rotation can cover the circular foundation (10); S7, a excavator enters the foundation (10) to excavate; S8, the portal truss (30) can be rotated to any angle, the hoisting device (40) can be moved to any place on the portal truss (30), the hoisting device (40) can walk, descend to any position in the foundation (10) to hoist earthwork, and then rise and move to the last end of the portal truss (30), run to the top of the earthwork truck outside the foundation (10), and unload the earthwork into the earthwork truck; after unloading, it is empty to the next hoisting earthwork operation in the excavation of the foundation (10); S9, according to the construction requirements, excavate, hoist, and unload the earthwork to excavate a circular foundation pit in the circular foundation (10); S10, installing a concrete delivery pipe (50) on the portal truss (30), and arranging a plurality of unloading outlets on the portal truss (30), arranging a concrete pumping device outside the foundation (10) and connecting it with the concrete delivery pipe (50), and pumping and pouring the concrete into the circular foundation pit through the concrete pumping device, the concrete delivery pipe (50) and the unloading outlet; the portal truss (30) rotates according to the construction requirements for rotary pouring; S11, after the pouring is completed, the portal truss (30) and the hoisting device (40) are removed.

2. The method according to claim 1, wherein, A central support hinge device (60) is arranged at the work center, the first end of the portal truss (30) is fixed to the central support hinge device (60), and the central support hinge device (60) can drive the portal truss (30) to rotate circumferentially.

3. The method according to claim 1, wherein, When hoisting earthwork, a soil taking box (70) is connected to the hoisting device (40) to load and unload earthwork.

4. The method according to claim 1, wherein, In step S9, the excavation operation progresses from the outer side close to the diaphragm wall (20) to the inner side close to the work center, and excavates layer by layer from high to low.

5. The method according to claim 1, wherein, In step S8, a hydraulic grab is connected to the hoisting device (40) for synchronous excavation.

6. The method according to claim 1, wherein, In step S10, a plurality of pump pipes (80) are arranged at the unloading outlets, and the upper and lower pump pipes (80) are detachably connected.

7. The method according to claim 1, wherein, In step S10, the row-vibration concrete vibrator (90) is hoisted on the hoisting device (40), and the row-vibration concrete vibrator (90) is synchronously operated to vibrate the concrete in the foundation pit when the concrete is poured into the circular foundation pit.

8. The method according to claim 1, wherein, In step S10, the concrete is poured through the concrete delivery pipe (50) and the discharge outlet, and the air pump (100) is arranged outside the foundation pit to synchronously pour the concrete into the foundation pit.

9. The method according to claim 1, wherein, In step S10, the pouring structure can be adjusted by adjusting the opening or closing of any discharge outlet, and the cushion layer (120), the bottom plate (130), the anchoring body filling core concrete body (140) and the anchoring body erosion-resistant peripheral concrete body (150) are formed by pouring in the foundation pit.

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