Anti-seepage foundation pit supporting structure without grooving and pipe burying and real-time monitoring construction method

Abstract

The invention relates to the technical field of municipal engineering construction, in particular to an anti-seepage foundation pit supporting structure without grooving and pipe burying and a real-time monitoring construction method.The anti-seepage foundation pit supporting structure comprises a pipeline extending in the X-axis direction; at least two steel sheet piles; the two steel sheet piles are symmetrically arranged on the two sides of the pipeline, each steel sheet pile is provided with a parallel section and bent sections at the two ends, an opening is reserved between the bent sections at the ends of the steel sheet piles located on the two sides of the pipeline, and a reinforcing and plugging assembly is arranged at the opening; the jet grouting piles are overlapped, gaps are complemented through the reinforcing piles, an underground water permeation channel is thoroughly cut off, and water gushing is completely eradicated; the jet grouting column wraps the buckling groove of the steel sheet pile, gap water seepage is blocked, the connection rigidity is enhanced, stress monitoring captures mechanical response of the pipeline in real time, the pipeline stress is controlled within a safety range, construction disturbance is reduced, and structural stability and pipeline safety are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of municipal engineering construction technology, and in particular to a trenchless pipe-buried seepage prevention foundation pit support structure and a real-time monitoring construction method. Background Technology

[0002] In municipal engineering construction, trenchless pipe laying techniques, such as pipe jacking, directional drilling, and pipe ramming, have become an important technical direction for water supply and drainage pipeline construction due to their significant advantages in situations with limited working space, difficulties in land acquisition, and deep burial. However, this technology still faces severe challenges in the subsequent well installation stage. When it is necessary to excavate a foundation pit above the already laid pipeline, the depth of the foundation pit support often exceeds the burial depth of the pipeline. The pipeline laid in the early stage makes it impossible for traditional support structures (such as steel sheet piles) to close, forming a structural gap. Especially in areas with high groundwater levels and sandy or silty soil layers, the intersection of the pipeline and the foundation pit is prone to quicksand phenomena, causing the foundation pit to accumulate or even collapse, seriously threatening construction safety and quality. Summary of the Invention

[0003] In view of the problems existing in the above-mentioned trenchless buried pipe seepage prevention pit support structure and real-time monitoring construction method, the present invention is proposed.

[0004] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a trenchless buried pipe seepage prevention foundation pit support structure, comprising, Pipelines extending along the X-axis; At least two sheet piles; Two sheet piles are symmetrically arranged on both sides of the pipeline, each having a parallel section and bent sections at both ends. The parallel section is parallel to the axis of the pipeline, and the bent section forms a 90° angle with the parallel section. The bent sections extend towards the pipeline along the Z-axis and are close to the outer wall of the pipeline, thereby forming a rectangular support frame for pipeline construction. An opening is reserved between the bent sections at the ends of the sheet piles on both sides of the pipeline. A reinforcement and sealing component is installed at the opening. The reinforcement and sealing component forms a rigid connection between the outer circumference of the pipeline and the bent section at the end of the sheet pile through consolidation. While constructing a stable overall support, it also achieves sealing and seepage prevention treatment of the opening.

[0005] In a preferred embodiment of the trenchless buried pipe seepage prevention foundation pit support structure of the present invention: the steel sheet pile is formed by interlocking several steel plates.

[0006] In a preferred embodiment of the trenchless buried pipe seepage prevention pit support structure of the present invention: the steel plate includes a U-shaped steel plate, the two ends of the U-shaped steel plate are radially rolled outward to form a snap-fit ​​groove, and adjacent steel plates are interlocked by the snap-fit ​​groove to achieve a tongue-and-groove connection.

[0007] In a preferred embodiment of the trenchless buried pipe anti-seepage foundation pit support structure of the present invention: a jet grouting column is provided on the outer periphery of the steel sheet pile. The jet grouting column is located between two adjacent steel sheet members and covers the interlocking groove connecting the two adjacent steel sheet members to form a continuous anti-seepage reinforcement node, which effectively blocks the seepage channel at the interlocking groove gap and enhances the overall connection rigidity of the steel sheet pile.

[0008] In a preferred embodiment of the trenchless buried pipe seepage prevention pit support structure of the present invention: the reinforcement and sealing component includes two jet grouting piles, which are symmetrically arranged on both sides of the pipe and at the corresponding opening positions. The two jet grouting piles overlap each other to form a whole, and perforations are provided at the positions of the pipes between the two jet grouting piles.

[0009] In a preferred embodiment of the trenchless buried pipe seepage prevention pit support structure of the present invention: the width of the overlapping part between the jet grouting piles on both sides of the pipe should be >0.25D, and D>1.5d, where D is the pile diameter of the jet grouting pile and d is the diameter of the pipe.

[0010] In a preferred embodiment of the trenchless buried pipe seepage prevention foundation pit support structure of the present invention: a reinforcing pile overlaps between the jet grouting pile and the nearest jet grouting column.

[0011] In a preferred embodiment of the trenchless buried pipe seepage prevention foundation pit support structure of the present invention: a waler is provided on the inner side of the steel sheet pile, and the waler is fixedly connected to the inner wall of the steel sheet pile by welding.

[0012] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a real-time monitoring construction method for anti-seepage pit support structures without trenching and buried pipes, which is applied to the anti-seepage pit support structures without trenching and buried pipes as described above, and includes the following steps: Determine the exact location and route of the pipeline; Conduct surveying and setting out of steel sheet piles and position construction equipment; Around the perimeter of the foundation pit, steel sheet piles are driven in both parallel and perpendicular directions to the pipeline, with openings left on both sides of the pipeline. Outside the sheet piles, jet grouting columns are driven between two adjacent sheet piles for water-stopping reinforcement. Deploy sensors; Jet grouting piles are driven on both sides of the pipeline, and the jet grouting piles and the nearby jet grouting columns are consolidated by driving reinforcement piles to form a stack; The walers are fabricated according to the dimensions of the rectangular support frame; When the foundation pit is excavated to a shallow depth, manual labor is used to install walers on the steel sheet piles, and corner bracing is used to reinforce the turning points. Continue excavation and monitor stress changes in nearby soil layers in real time using sensors.

[0013] In a preferred embodiment of the real-time monitoring construction method for the anti-seepage pit support structure without trenching and buried pipes described in this invention: the sensor is either a fiber optic strain gauge or a resistance strain gauge.

[0014] The beneficial effects of this invention are as follows: This invention uses overlapping jet grouting piles and fills the gaps with reinforcing piles to completely cut off the groundwater seepage channels and prevent water inrush and piping; the jet grouting columns cover the steel sheet pile interlocking grooves to block water seepage in the gaps and enhance the connection rigidity; stress monitoring captures the mechanical response of the pipeline in real time, controls the pipeline stress within a safe range, reduces construction disturbance, and ensures structural stability and pipeline safety. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A three-dimensional structural diagram of a trenchless buried pipe seepage prevention foundation pit support structure is shown; Figure 2 A structural diagram of steel sheet piles in a trenchless seepage prevention foundation pit support structure is shown; Figure 3 It shows Figure 1 Enlarged structural diagram at point A in the middle; Figure 4 The diagram shows the structure of the reinforcement and sealing component in the anti-seepage pit support structure without trenching and buried pipes; Figure 5 The diagram shows the sensor placement locations in a real-time monitoring construction method for seepage-proof foundation pit support structures without trenching and pipe embedding. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0018] Reference Figure 1-3This embodiment provides a trenchless pipe-buried seepage prevention foundation pit support structure, including: Pipeline 1 extending along the X-axis; At least two sheet piles 2, each sheet pile 2 is formed by interlocking several steel plate pieces 21, each steel plate piece 21 including a U-shaped steel plate 211, the two ends of the U-shaped steel plate 211 are radially rolled outward to form interlocking grooves 212, and adjacent steel plate pieces 21 are interlocked with each other through the interlocking grooves 212 to achieve tongue and groove connection. Two sheet piles 2 are symmetrically arranged on both sides of the pipeline 1, and each has a parallel section and a bent section at both ends. The parallel section is parallel to the axis of the pipeline 1, and the bent section is at a 90° angle to the parallel section. They extend along the Z-axis towards the pipeline 1 and are close to the outer wall of the pipeline 1, thereby forming a rectangular support frame for the construction of the pipeline 1. An opening 3 is reserved between the bent sections at the ends of the sheet piles 2 on both sides of the pipeline 1. The distance between the bent sections of the pipeline 1 and the sheet piles on both sides is controlled within the range of ≤0.2m. It should be noted that when excavating a foundation pit above an already laid pipeline 1, the depth of the foundation pit support often exceeds the burial depth of the pipeline. The previously laid pipeline prevents the traditional support structure (such as sheet piles 2) from closing, forming a structural gap (opening 3). This gap can lead to the following problems: First, it disrupts the integrity and continuity of the support structure, causing a sharp drop in the stiffness of the support system. During the excavation of the foundation pit, stability problems such as lateral displacement and excessive deformation are likely to occur. Second, the gap becomes a seepage channel for groundwater, which can easily cause seepage damage such as water inrush and piping in the foundation pit, threatening the safety of the foundation pit construction. Third, the stress concentration around the gap is significant, which may cause local instability or cracking of the bent section at the end of the sheet pile 2, further aggravating the failure risk of the support structure.

[0019] Furthermore, a reinforcement and sealing component 4 is installed at the opening 3. The reinforcement and sealing component 4 forms a rigid connection between the outer circumference of the pipe 1 and the end bend of the steel sheet pile 2 through consolidation, thereby achieving sealing and seepage prevention treatment of the opening 3 while constructing an overall stable support.

[0020] This design uses a reinforced sealing component 4 to rigidly connect the pipe 1 and the sheet pile 2, thereby filling the structural gap. On the one hand, it improves the overall stability of the sheet pile 2, avoiding local instability or cracking caused by stress concentration, and ensuring the lateral stiffness and deformation control of the sheet pile 2 at the gap during the excavation of the foundation pit. On the other hand, it completely seals the groundwater seepage channel at the gap, eliminating the risk of seepage damage such as water inrush and piping from the root. It solves the technical problem that traditional support structures cannot close under the condition of already laid pipe 1, and provides a safe and reliable technical solution for foundation pit support under complex conditions in urban underground engineering.

[0021] As an optional embodiment: It should be noted that the sheet pile 2 is formed by interlocking several adjacent steel plates 21 through interlocking grooves 212 to achieve a tongue-and-groove connection. However, there will be gaps between the interlocking grooves 212, which will become seepage channels for groundwater. Continuous seepage of groundwater can easily lead to an increase in the water content of the soil around the foundation pit, resulting in an increase in the soil's self-weight and a decrease in shear strength, which in turn exacerbates the settlement or deformation of the foundation pit sidewall. At the same time, long-term water seepage may cause erosion of the connection nodes of the sheet pile 2, reduce the mechanical properties of the interlocking parts, and affect the overall durability of the support structure.

[0022] Reference Figure 3 In one embodiment provided in this application, a jet grouting column 5 is provided on the outer periphery of the sheet pile 2. The jet grouting column 5 is located between two adjacent steel plate pieces 21 and covers the interlocking groove 212 connecting the two adjacent steel plate pieces 21, forming a continuous anti-seepage reinforcement node, effectively blocking the seepage channel at the gap of the interlocking groove 212 and enhancing the overall connection rigidity of the sheet pile 2.

[0023] Specifically, the jet grouting column 5 is generated using a high-pressure jet grouting process. A hole is drilled at a predetermined position at the connection node of adjacent steel plate members 21 using a dedicated jet grouting equipment. A grouting pipe with a nozzle is inserted into the hole, and a high-pressure pump is used to eject cement-based grout from the nozzle in the form of a high-pressure jet stream, impacting and cutting the surrounding soil and mixing it thoroughly. At the same time, the grouting pipe rotates around the axis and is raised at a uniform speed, so that the grout and soil form a continuous columnar solidified body. This design completely seals the seepage path of the joint groove 212 gap through the physical barrier effect of the jet grouting column 5, avoiding soil instability and node erosion problems. At the same time, the jet grouting column 5 and the steel sheet pile 2 work together to increase the connection stiffness of adjacent steel plate members 21, ensuring the overall bearing capacity of the steel sheet pile 2 support.

[0024] As an optional embodiment: Reference Figure 4 In one embodiment provided in this application, the reinforcement and sealing component 4 includes two jet grouting piles 41, which are symmetrically arranged on both sides of the pipe 1 and at the corresponding opening 3 positions. Two jet grouting piles 41 overlap each other to form a whole, and a perforation 42 is provided between the two jet grouting piles 41 at the position corresponding to the pipe 1.

[0025] The width of the overlapping portion between the jet grouting piles 41 on both sides of the pipeline 1 should be >0.25D, and D >1.5d, where D is the pile diameter of the jet grouting pile 41 and d is the diameter of the pipeline 1. The two jet grouting piles 41 overlap each other to form a whole, so that there is no gap between them and the possibility of groundwater seepage is eliminated.

[0026] It should be noted that the jet grouting pile 41 is generated using a high-pressure jet grouting process. A hole is drilled at a predetermined position at the connection node of adjacent steel plate components 21 using a special jet grouting equipment. A grouting pipe with a nozzle is placed into the hole, and a high-pressure pump is used to spray cement-based grout from the nozzle in the form of a high-pressure jet stream. This grout impacts and cuts the surrounding soil and mixes it thoroughly with the soil. At the same time, the grouting pipe rotates around the axis and is lifted at a uniform speed, so that the grout and soil form a continuous columnar solidified body. Since a perforation 42 needs to be reserved at the position of the pipe 1, a variable diameter jetting process is adopted. The area in the middle section of the jet grouting pile 41 corresponding to the pipe 1 is formed by adjusting the jetting pressure, nozzle flow rate and lifting speed to form a necked section with a diameter smaller than the solidified body at both ends. This necked section is the reserved perforation 42 that matches the pipe 1. However, due to the use of variable diameter jetting, one side of the pipe 1 is just stuck on the outer periphery of the pipe 1, while there is a C-shaped gap between the other side and the jet grouting column 5, which will cause groundwater seepage. Furthermore, a reinforcing pile 6 overlaps between the jet grouting pile 41 and the nearest jet grouting column 5; Specifically, the construction method of the reinforcement pile 6 is as follows: a hole is drilled between the jet grouting pile 41 and the jet grouting column 5, and a grouting pipe with a nozzle is placed into the hole. The cement-based grout is injected from the nozzle in the form of a high-pressure jet stream using a high-pressure pump, which impacts and cuts the surrounding soil and mixes it thoroughly. At the same time, the grouting pipe rotates around the axis and is raised at a uniform speed, so that the grout and the soil form a continuous columnar solidified body. At the C-shaped notch position, the injection pressure, nozzle flow rate and lifting speed are increased to fill the C-shaped notch, so that the jet grouting pile 41 and the jet grouting column 5 completely overlap and form a whole. This design integrates the jet grouting pile 41 and the jet grouting column 5 into a single structure by reinforcing pile 6, effectively solving the problem of weak seepage prevention caused by variable diameter jetting.

[0027] A waler 7 is provided on the inner side of the sheet pile 2, and the waler 7 is fixedly connected to the inner wall of the sheet pile 2 by welding.

[0028] As an optional embodiment: In one embodiment provided in this application, a real-time monitoring construction method for a trenchless buried pipe seepage prevention pit support structure is applied to the aforementioned trenchless buried pipe seepage prevention pit support structure, comprising the following steps: Determine the exact location and route of Pipeline 1; Conduct surveying and setting out of steel sheet piles and position construction equipment; Around the perimeter of the foundation pit, steel sheet piles 2 are driven in a full range along the direction parallel to pipe 1 and perpendicular to pipe 1, with openings 3 left on both sides of pipe 1. Outside the sheet pile 2, jet grouting columns 5 are driven between two adjacent steel sheet members 21 for water-stopping reinforcement. Deploy sensors; Jet grouting piles 41 are driven on both sides of pipeline 1, and the jet grouting piles 41 and the nearby jet grouting columns 5 are consolidated by driving reinforcement piles 6 to form a stack. The waler 7 is fabricated according to the dimensions of the rectangular support frame; When the foundation pit is excavated to a shallow depth, manual labor is used to install walers 7 on the sheet piles 2, and corner bracing is used to reinforce the turning points. Continue excavation and monitor stress changes in nearby soil layers in real time using sensors.

[0029] When deploying sensors: The location of the jet grouting pile 41 grouting point needs to be determined to ensure good sealing and water-stopping performance of the water-stopping reinforcement area. Reference Figure 5 Sensors are installed on the vertical plane between the grouting point of the jet grouting pile 41 and the pipe 1. They are arranged in a circumferential manner starting from the lowest point of the pipe 1, close to the outer surface of the pipe wall. The spacing between the sensors is Π / 8, and the arc can be flexibly arranged according to the pipe diameter of the pipe 1. If the burial depth of pipe 1 is relatively small and the groundwater is relatively shallow, part of the soil can be excavated to install sensors between pipe 1 and the construction area of ​​jet grouting pile 41 to capture the mechanical response of pipe 1 in real time. If the pipeline 1 is buried deep or far from the groundwater layer, in order to eliminate the interference of the existing pipeline 1 on the monitoring, the sensor deployment points are evenly divided into left and right parts along the axis of symmetry, with the central axis of the jet grouting piles 41 to be installed on both sides of the pipeline 1 as the symmetry reference, so as to realize the capture of the mechanical response of the pipeline 1.

[0030] The sensor can be either a fiber optic strain gauge or a resistance strain gauge.

[0031] To mitigate the impact of jet grouting pile 41 construction on pipeline 1, the specific monitoring construction method is as follows: When the high-pressure jet grouting drill rod is lifted from bottom to top, if the monitored stress value measured by the sensor on the central axis of the intersection surface of the drill rod exceeds 50%ff, which is the material strength of pipe 1, an alarm will be issued. This can be achieved by reducing the water, air, and slurry injection pressure in the multi-pipe construction method, while simultaneously reducing the lifting speed of the high-pressure jet grouting drill rod. This will ensure a certain reinforcement effect while reducing the impact of high-pressure injection on pipe 1, thus mitigating the impact of high-pressure injection on pipe 1.

[0032] If the sensor does not respond to the alarm, construction will proceed according to the construction method for the high-pressure jet grouting piles to be driven.

[0033] This design uses real-time sensor monitoring and dynamic control of construction parameters to keep the stress response of pipeline 1 within 40%ff of the material strength, minimizing the disturbance to the existing pipeline 1 caused by jet grouting and foundation pit excavation, and avoiding the risk of pipeline 1 damage. Compared with traditional construction methods, it has a shorter construction period, lower construction cost, and does not require large-scale surface excavation, reducing the impact on the surrounding environment and traffic. It is especially suitable for foundation pit projects in dense urban underground pipe networks and has broad application prospects.

[0034] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A diaphragm wall structure for a cut-off foundation support, characterized by: The utility model relates to a kind of pipeline construction support frame, including, The pipeline (1) is arranged along the direction of X axis; At least two steel sheet piles (2); Two The steel sheet piles (2) are symmetrically arranged on the two sides of the pipeline (1), and each has a parallel section and a bent section at both ends, wherein the parallel section is parallel to the axis of the pipeline (1), the bent section has a 90° angle with the parallel section, and extends along the Z-axis direction to the side of the pipeline (1) and is close to the outer wall of the pipeline (1), thereby enclosing a rectangular support frame for pipeline (1) construction. An opening (3) is reserved between the end bent sections of the steel sheet piles (2) on both sides of the pipeline (1), and a reinforcing plugging assembly (4) is arranged at the opening (3). The reinforcing plugging assembly (4) forms a rigid connection between the outer peripheral surface of the pipeline (1) and the end bent sections of the steel sheet piles (2) through consolidation, achieving sealing and anti-seepage treatment of the opening (3) while building a stable overall support.

2. The impervious excavation support structure of unslotted buried pipe according to claim 1, characterized in that: The steel sheet pile (2) is formed by buckling a plurality of steel sheet pieces (21).

3. The impervious excavation support structure of unslotted buried pipe according to claim 2, characterized in that: The steel sheet piece (21) includes a U-shaped steel sheet (211), and the two ends of the U-shaped steel sheet (211) are radially outwardly rolled to form a buckling groove (212). The adjacent steel sheet pieces (21) are embedded in each other through the buckling groove (212) to achieve a tongue-and-groove connection.

4. The impervious excavation support structure of unslotted buried pipe according to claim 3, characterized in that: The outer periphery of the steel sheet pile (2) is provided with a rotary jet column (5), which is located between the adjacent two steel sheet pieces (21) and covers the buckling groove (212) connecting the adjacent two steel sheet pieces (21), forming a continuous anti-seepage reinforcing node, blocking the water seepage channel at the joint of the buckling groove (212) and enhancing the overall connection stiffness of the steel sheet pile (2).

5. The impervious excavation support structure of unslotted buried pipe according to claim 4, characterized in that: The reinforcing plugging assembly (4) includes two rotary jet columns (41), which are symmetrically arranged on both sides of the pipeline (1) and correspond to the position of the opening (3). The two rotary jet columns (41) overlap each other to form a whole, and a perforation (42) is provided between the two rotary jet columns (41) corresponding to the position of the pipeline (1).

6. The impervious foundation pit support structure of the unslotted buried pipe and the real-time monitoring construction method according to claim 5, characterized in that: The overlapping part between the rotary jet columns (41) on both sides of the pipeline (1) should be greater than 0.25D, and D>1.5d, where D is the diameter of the rotary jet column (41), and d is the diameter of the pipeline (1).

7. The impervious excavation support structure of unslotted buried pipe according to claim 6, characterized in that: The rotary jet column (41) overlaps with the nearest rotary jet column (5).

8. The impervious excavation shoring structure of unslotted buried pipe according to claim 1, characterized in that: The inner side of the steel sheet pile (2) is provided with a surrounding purlin (7), which is fixedly connected with the inner wall of the steel sheet pile (2) by welding.

9. A real-time monitoring construction method of a trenchless pipe embedded anti-seepage foundation support structure, applied to the trenchless pipe embedded anti-seepage foundation support structure according to any one of claims 1-8, characterized in that: The method comprises the following steps: Determine the specific position and direction of the pipeline (1); Measure and lay out the steel sheet pile and position the construction equipment; Around the foundation pit, along the direction parallel to the pipeline (1) and perpendicular to the pipeline (1), the steel sheet pile (2) is filled and driven, and an opening (3) is left on both sides of the pipeline (1); On the outside of the steel sheet pile (2), rotary jet columns (5) are driven between the adjacent two steel sheet pieces (21) for water stopping and reinforcing; Lay the sensor; Drive rotary jet columns (41) on both sides of the pipeline (1), and consolidate the rotary jet columns (41) and the rotary jet columns (5) near them by driving reinforcing columns (6) to form a stack; According to the size of the rectangular support frame, the surrounding purlin (7) is processed; When the foundation pit is excavated to a relatively shallow depth, the surrounding purlin (7) is installed on the steel sheet pile (2) by artificial access, and the corner support is used for reinforcement at the turning point; Continue to excavate, and monitor the stress change of the soil layer near the excavation in real time through the sensor.

10. The method of real-time monitoring construction of a cutoff trenchless buried pipe's anti-seepage foundation support structure according to claim 9, characterized in that: The sensor adopts any one of a fiber grating strain gauge or a resistance strain gauge.

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