Mechanical integrated design of cement mixing pile for soft soil with silt

Abstract

This invention relates to the field of cement mixing pile construction technology, specifically to a mechanized integrated design for cement mixing piles in silty soft soil. The design includes a mobile box with a control console fixedly connected to its top. A mixing mechanism is mounted on top of the control console. This mixing mechanism comprises a robotic arm, a fixed frame, and a protective cover. Positioning is achieved through the mixing mechanism, a mast, and the robotic arm. After positioning, the robotic arm's telescopic rod pushes the fixed frame downwards, inserting the protective cover into the ground. Once inserted, a motor rotates, driving the mixing blades to rotate and mix the cement. During the sinking and mixing process, the soil stress gradient can be monitored in real time. By dynamically adjusting the grout injection pressure and flow rate, insufficient grout injection pressure and range are avoided, thus ensuring the construction quality of the cement mixing pile. To ensure the permeability of the cement grout, the injection pressure and drill bit speed work synergistically during the sinking and mixing process, with high-pressure injection combined with low-speed mixing.

Description

Technical Field

[0001] This invention relates to an integrated mechanical design for cement mixing piles in silty soft soil, belonging to the field of cement mixing pile construction technology. Background Technology

[0002] Cement mixing piles are the most common and widely used method for reinforcing weak foundations both domestically and internationally, frequently applied in railway engineering, highway engineering, municipal engineering, and many other fields. In particular, many large and medium-sized cities in my country are located along the coast and rivers, covering nearly half of the country's prefecture-level cities and representing the most densely urbanized areas, accounting for over 80% of the national GDP. However, traditional cement mixing piles have a low degree of mechanical automation, resulting in the following problems:

[0003] 1. Foundation Treatment in the Construction Area. Before constructing cement mixing piles, the foundation treatment area requires earthwork replacement to ensure the bearing capacity of the foundation meets the equipment construction requirements. However, the replacement area is limited by multiple factors, including surface water availability, replacement materials, and construction progress. Because the surrounding water system is densely distributed around silty soft soil, the replacement material is prone to liquefaction, requiring multiple replacement treatments, thus increasing construction costs. Furthermore, the preparation of replacement materials damages the ecological environment, which contradicts the concept of green development.

[0004] 2. Equipment Height. In existing cement mixing pile construction, the drill rod length is typically matched to the corresponding pile length, resulting in a relatively high tower height. If the equipment operates on weak foundations with low bearing capacity or in areas with poor ground flatness, the high center of gravity of the machinery makes it highly susceptible to overturning and poses a significant stability risk. Furthermore, the height of the machinery tower is easily affected by other structures and overhead power lines.

[0005] 3. Cement grout waste. During cement mixing pile construction, a large amount of cement grout is wasted in the construction area. In some sites, the thickness of the grout layer at the pile top can even exceed 30cm, causing serious pollution and making cleanup difficult. The main reasons are: the specific gravity of the cement grout cannot be adjusted according to the moisture content of the soil layer, leading to a large amount of cement grout overflowing to the surface in the upper soil layer with high moisture content; also, during the movement and positioning of machinery, the cement grout pump is not shut down in time to save work efficiency. Therefore, achieving energy and material conservation during pile foundation construction is one of the key considerations.

[0006] 4. Pile Foundation Quality. According to the construction principle of cement-mixed piles, cement grout is thoroughly mixed with the existing soft soil to form a pile body with a certain strength. However, in actual construction, due to the influence of subjective and objective factors, the grouting pressure from the pile head to the pile tip is generally kept constant, without considering the influence of soil stress gradient on the grouting pressure and grouting range. This is the reason why cement-mixed piles form conical piles after construction (i.e., the upper part of the pile diameter is larger than the design pile diameter, and the lower part is smaller than the design pile diameter); in some cases, the lower part of the pile cannot be formed, resulting in pile breakage.

[0007] 5. Verticality and Planar Position of Construction Pile Foundations. After the construction of cement-mixed pile foundations, the verticality and planar position of the piles are key control indicators to ensure the bearing capacity and overall stability of the cement-mixed pile composite foundation. Considering that cement-mixed piles are not yet formed and have virtually no bearing capacity in the early stages of construction, the existing cement-mixed piles are driven using a backward piling method. This construction method destroys the existing layout points of the pile body, meaning that the planar position and verticality of the pile foundation mainly rely on the experience judgment of the machine operator, which will seriously affect the bearing capacity of the cement-mixed piles.

[0008] Therefore, a mechanically integrated design for cement mixing piles in silty soft soil is proposed. Summary of the Invention

[0009] In view of this, the present invention provides a mechanically integrated design for cement mixing piles in silty soft soil, in order to solve or alleviate the technical problems existing in the prior art, and at least provide a beneficial option.

[0010] The technical solution of the present invention is implemented as follows: A mechanically integrated design for cement mixing piles in silty soft soil includes a mobile box, a control console fixedly connected to the top of the mobile box, a mixing mechanism provided on the top of the control console, the mixing mechanism including a mechanical arm, a fixed frame and a protective cover, the bottom of the mechanical arm fixedly connected to the top of the mobile box, the left side of the fixed frame fixedly connected to the right side of the mechanical arm, a connecting arm movably connected to the right side of the fixed frame, and a protective cover fixedly connected to the bottom of the connecting arm.

[0011] More preferably, a rotating motor is fixedly connected to the right side of the connecting arm, and the output end of the rotating motor is fixedly connected to the top of the protective cover.

[0012] More preferably, a stirring rod is movably connected inside the protective cover, and stirring blades are fixedly connected to the surface of the stirring rod.

[0013] More preferably, there are two protective covers, which are the same size and in opposite positions.

[0014] More preferably, a grouting pipe is fixedly connected to the right side of the fixing frame, and the right side of the grouting pipe is fixedly connected to the protective cover.

[0015] More preferably, the bottom of the mobile box is provided with a hydraulic suspension module, and the bottom of the mobile box is movably connected with tracks.

[0016] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions:

[0017] I. This invention uses a mixing mechanism, positioned by a mast and a robotic arm. After positioning, the robotic arm's telescopic rod pushes the fixed frame downwards, and the fixed frame inserts the protective cover into the ground. After insertion, the motor rotates to drive the mixing blades to rotate, and the mixing blades mix the cement. During the sinking and mixing process, the soil stress gradient can be monitored in real time. By dynamically adjusting the grout injection pressure and flow rate, insufficient grout injection pressure and range are avoided, thereby ensuring the construction quality of the cement mixing pile.

[0018] In addition, to ensure the permeability of the cement grout, a protective casing is installed on the outside of the blade and a spiral blade is installed on the top. During the sinking and mixing process, the grouting pressure and the drill bit speed work together to ensure the homogeneity of the pile foundation in all directions.

[0019] Second, this invention addresses the issue that cement mixing pile construction often results in significant cement slurry waste, causing severe pollution and cleaning difficulties. To achieve energy and material conservation during construction, the mixing blade module monitors the moisture content of different soil layers and adjusts the water-cement ratio in real time. This reduces cement slurry overflow in the upper soil layers with higher moisture content. Furthermore, the cement slurry pump is promptly shut off during the movement and positioning of the machinery.

[0020] Third, traditional cement mixing pile foundations are driven backwards, a construction process that damages existing pile layout points. During construction, the horizontal and vertical alignment of the piles relies heavily on the subjective experience of the machine operator. Considering that the verticality and horizontal alignment of the piles are key control indicators for the bearing capacity and overall stability of cement mixing pile composite foundations, this invention uses a robotic arm module mounted on a main mast to control verticality and horizontal alignment, thereby ensuring the various physical parameters of the pile foundation. Simultaneously, it significantly reduces equipment travel distance, achieving energy conservation and emission reduction during construction. Furthermore, the number of mixing blades mounted on the robotic arm can be increased or decreased according to different construction conditions, enabling optimized construction.

[0021] Fourth, considering the weak bearing capacity of the foundation in the cement mixing pile treatment area during the movement of the machinery, a four-track hydraulic suspension system is adopted to enhance the adaptability of the machinery and reduce shearing of the replacement soil, thereby increasing the equipment's mobility and ability to escape obstacles. Additionally, the relatively high center of gravity of the machinery makes it prone to overturning and poses a significant stability risk. Therefore, this invention employs a four-track hydraulic suspension system to intelligently adjust the chassis and the hydraulic drill rod mounted on the robotic arm to lower the equipment height. This ensures the normal operation of the equipment and reduces the impact of other structures and overhead lines on the pile foundation construction.

[0022] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the three-dimensional front view structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the track structure of the present invention;

[0026] Figure 3 For the present invention Figure 1 A magnified structural diagram of part A in the middle;

[0027] Figure 4 This is a schematic diagram of the structure of the protective cover of the present invention;

[0028] Figure 5 This is a cross-sectional structural schematic diagram of the protective cover of the present invention.

[0029] Reference numerals: 1. Moving box; 2. Control console; 3. Mixing mechanism; 301. Mechanical arm; 302. Fixed frame; 303. Protective cover; 4. Connecting arm; 5. Rotating motor; 6. Mixing rod; 7. Mixing blade; 8. Grouting pipe; 9. Track. Detailed Implementation

[0030] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0031] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0032] Example 1

[0033] like Figure 1-5 As shown, this embodiment of the invention provides a mechanically integrated design for cement mixing piles in silty soft soil, including a mobile box 1. A control console 2 is fixedly connected to the top of the mobile box 1. A mixing mechanism 3 is provided on the top of the control console 2. The mixing mechanism 3 includes a mechanical arm 301, a fixed frame 302, and a protective cover 303. The bottom of the mechanical arm 301 is fixedly connected to the top of the mobile box 1. The left side of the fixed frame 302 is fixedly connected to the right side of the mechanical arm 301. A connecting arm 4 is movably connected to the right side of the fixed frame 302. The bottom of the connecting arm 4 is fixedly connected to the protective cover 303. A rotary motor 5 is fixedly connected to the right side of the connecting arm 4. The output end of the rotary motor 5 is fixedly connected to the top of the protective cover 303. A mixing rod 6 is movably connected inside the protective cover 303. A mixing blade 7 is fixedly connected to the surface of the mixing rod 6. There are two protective covers 303, which are the same size and opposite in position.

[0034] During the mixing process via the mixing mechanism 3, the robotic arm 301 moves the fixed frame 302 downwards, and the fixed frame 302 inserts the protective cover 303 into the ground. After insertion, the rotating motor 5 drives the mixing blades 7 to rotate, thus mixing the cement. During the sinking and mixing process, the soil stress gradient can be monitored in real time, and the grout injection pressure and flow rate can be dynamically adjusted to avoid insufficient grout injection pressure and range, thereby ensuring the construction quality of the cement mixing pile. In addition, to ensure the permeability of the cement grout, a protective casing is installed outside the blades and a spiral blade is installed on the upper part. During the sinking and mixing process, the injection pressure and drill bit speed work together to prevent the grout from surging upwards.

[0035] Cement mixing pile foundations are driven backwards, a construction technique that damages existing pile layout points. During construction, the horizontal and vertical positions of the piles rely heavily on the subjective judgment of the machine operator. Considering that the verticality and horizontal position of the piles are key control indicators for the bearing capacity and overall stability of the cement mixing pile composite foundation, a robotic arm 301 module mounted on the main mast is used to control verticality and horizontal position, thereby ensuring the various physical parameters of the pile foundation. If the equipment moves on weak foundations with low bearing capacity or in areas with poor ground flatness, the center of gravity of the machinery will be high, making it prone to overturning and posing a significant stability risk. Therefore, the robotic arm 301, equipped with a hydraulic drill rod, is used to lower the equipment height, while also reducing the impact of other structures and overhead lines on the pile foundation construction.

[0036] Example 2

[0037] like Figure 1-5 As shown, in one embodiment, a grouting pipe 8 is fixedly connected to the right side of the fixed frame 302, and the right side of the grouting pipe 8 is fixedly connected to the protective cover 303. A hydraulic suspension module is provided at the bottom of the mobile box 1, and a track 9 is movably connected to the bottom of the mobile box 1.

[0038] The grouting pipe 8 causes significant waste of cement slurry during cement mixing pile construction, leading to severe pollution and difficult cleanup. To achieve energy and material conservation during construction, the mixing blade module 7 monitors the moisture content of different soil layers and adjusts the water-cement ratio in real time, reducing cement slurry overflow in the upper soil layer with higher moisture content. The cement slurry pump is shut off promptly during equipment movement and positioning. A hydraulic suspension module is used in areas with weak foundation bearing capacity, and a four-track system 9 is employed to enhance the machine's adaptability. Furthermore, to reduce shearing of the replacement soil and increase the equipment's mobility and obstacle avoidance during movement, a hydraulic suspension system is used. The fixed frame 302 is equipped with an intelligent layout system. First, a positioning layout is performed on the main mast, and then precise positioning is achieved at the end of the two-axis robotic arm 301, ensuring the verticality and planar position of the pile foundation. Simultaneously, this significantly reduces the equipment's travel distance, achieving energy conservation and emission reduction during construction. In addition, the number of mixing blades on the robotic arm 301 can be increased or decreased according to different construction conditions to achieve reasonable construction.

[0039] In operation, this invention first moves the equipment to the mixing position via tracks 9. Then, the protective cover 303 is inserted into the ground via the robotic arm 301. Next, the rotating motor 5 is started, driving the mixing blades 7 to rotate and mix the cement. During mixing, different moisture contents are monitored, and water-cement ratios are injected through the grouting pipe 8 to prevent slurry from overflowing onto the ground. Cement mixing pile construction often results in significant waste of cement slurry, causing serious pollution and cleaning difficulties at the construction site. To achieve energy and material conservation during construction, the mixing blades 7 module monitors the moisture content of different soil layers and adjusts the water-cement ratio in real time, reducing cement slurry overflow in the upper soil layers with higher moisture content. During the movement and positioning of the machinery, the cement slurry pump is shut off promptly. A four-track system 9 is used in the cement mixing pile treatment area where the foundation bearing capacity is weak, enhancing the machine's adaptability.

[0040] Meanwhile, considering the need to reduce shearing of the replacement soil during machinery movement and increase the equipment's mobility and obstacle-avoidance capabilities, a hydraulic suspension system is adopted. The fixed frame 302 is equipped with an intelligent layout system. First, a positioning layout is performed on the main mast, and then a precise positioning layout is achieved at the end of the two-axis robotic arm 301, thus ensuring the verticality and planar position of the pile foundation. Simultaneously, this significantly reduces the equipment's travel distance, achieving energy conservation and emission reduction during construction. Furthermore, the number of mixing blades on the robotic arm 301 can be increased or decreased according to different construction conditions to achieve reasonable construction. Cement mixing pile foundations are driven by retreating piles, a construction process that would damage existing pile foundation layout points. During construction, the planar position and verticality of the pile foundation mainly rely on the subjective experience of the machinery operator. Considering that the verticality and planar position of the pile foundation are key control indicators for the bearing capacity and overall stability of the cement mixing pile composite foundation, the verticality and planar position are controlled by the robotic arm 301 module mounted on the main mast, thereby ensuring the various physical parameters of the pile foundation. If the equipment moves on a soft foundation with weak bearing capacity or in an area with poor ground flatness, the center of gravity of the mechanical equipment will be high, making it prone to overturning and posing a great risk to stability. Therefore, the use of the 301 robotic arm equipped with a hydraulic drill rod can reduce the height of the equipment and reduce the impact of other structures and high-altitude lines on the pile foundation construction.

[0041] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A mechanically integrated design for cement mixing piles in silty soft soil, comprising a mobile box (1), characterized in that: The top of the mobile box (1) is fixedly connected to a control console (2), and the top of the control console (2) is provided with a stirring mechanism (3). The stirring mechanism (3) includes a robotic arm (301), a fixed frame (302) and a protective cover (303). The bottom of the robotic arm (301) is fixedly connected to the top of the mobile box (1), the left side of the fixed frame (302) is fixedly connected to the right side of the robotic arm (301), and a connecting arm (4) is movably connected to the right side of the fixed frame (302). The bottom of the connecting arm (4) is fixedly connected to the protective cover (303).

2. The integrated mechanical design of cement mixing piles for silty soft soil according to claim 1, characterized in that: A rotating motor (5) is fixedly connected to the right side of the connecting arm (4), and the output end of the rotating motor (5) is fixedly connected to the top of the protective cover (303).

3. The integrated mechanical design of cement mixing piles for silty soft soil according to claim 1, characterized in that: The protective cover (303) is movably connected to a stirring rod (6), and a stirring blade (7) is fixedly connected to the surface of the stirring rod (6).

4. The integrated mechanical design of cement mixing piles for silty soft soil according to claim 3, characterized in that: Two protective covers (303) are provided, and the two protective covers (303) are the same size and opposite in position.

5. The integrated mechanical design of cement mixing piles for silty soft soil according to claim 1, characterized in that: The right side of the fixing frame (302) is fixedly connected to the grouting pipe (8), and the right side of the grouting pipe (8) is fixedly connected to the protective cover (303).

6. The integrated mechanical design of cement mixing piles for silty soft soil according to claim 1, characterized in that: The bottom of the mobile box (1) is provided with a hydraulic suspension module, and the bottom of the mobile box (1) is movably connected with a track (9).

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