Mechanical obstacle clearing method and system for shield crossing type steel joint underground continuous wall

Abstract

The application provides a mechanical obstacle removing method and system for a shield crossing type steel joint underground continuous wall, which first determines a wall section to be removed and a type steel joint located in a shield crossing range; then a vertical drilling hole is arranged at a position of the underground continuous wall away from a foundation pit, a full casing full rotary drilling machine is used to segmentally drill, segmentally cut and remove the wall body concrete and the type steel joint, and the vertical obstacle removing hole is backfilled; a horizontal or near horizontal drilling hole is arranged at a position of the underground continuous wall near the foundation pit, a horizontal diamond drilling machine is used to cut and remove the type steel joint in the shield hole door range, and the horizontal obstacle removing hole is plugged or backfilled; and finally, shield machine crossing construction is implemented. The obstacle removing method has clear removing targets, can realize lateral mechanical obstacle removing of the underground continuous wall with the type steel joint without large-diameter obstacle removing wells and without artificial obstacle removing by underground excavation, has been verified by indoor and field tests, and is suitable for use in a subway station crossing engineering with limited site.

Description

Technical Field

[0001] This invention belongs to the field of tunnel shield construction technology, specifically relating to a mechanical obstacle removal method and system for shield tunneling through a steel joint underground continuous wall. Background Technology

[0002] With the accelerating pace of urbanization, urban rail transit construction has entered a stage of high-density, layered development. Many cities, in the early stages of subway station construction, only designed and constructed them in conjunction with the current lines, without adequately reserving conditions for subsequent lines to pass through. Meanwhile, subsequent planning often adjusts based on urban land use, transportation corridors, and transfer organization, forcing the tunnel boring machine (TBM) of new subway sections to pass near existing stations or their foundation pit retaining structures. As a result, the foundation pit retaining structures of existing stations, originally intended for retaining soil and water, become rigid obstacles to the new TBM tunnels, becoming a significant factor restricting line completion and construction organization.

[0003] In water-rich soft soil strata, to ensure the safe excavation and long-term stability of station foundation pits, an open-cut construction method is typically adopted, with diaphragm walls providing good rigidity and water-stopping performance as the main retaining structure. These diaphragm walls are often buried at depths of 30 meters or even greater, and are quite thick. Furthermore, to improve the wall's integrity, bending resistance, and joint waterproofing, steel joints are often installed at the joints. While this structure is necessary for station construction, it is extremely unfavorable for subsequent tunnel boring machine (TBM) crossings: the TBM's excavation section is completely cut off by the entire diaphragm wall. In front of the cutterhead, in addition to high-strength concrete, there may be steel joints with strength and toughness far exceeding that of concrete, directly blocking the TBM's conventional excavation route and consequently affecting the phased implementation and network completion of the entire city's subway system.

[0004] Faced with existing diaphragm walls in railway stations, especially those with steel joints, various methods for clearing obstacles or creating space have been tried, but all have drawbacks that make them difficult to promote. Firstly, constructing dedicated clearing wells, while allowing for partial removal or cutting of the diaphragm wall obstructing tunnel boring, requires specific site conditions, takes a long time, and necessitates deep foundation pit support, resulting in high overall costs and making it unsuitable for repeated use in urban areas with limited space around existing stations. Secondly, using tunnel boring machines (TBMs) for clearing requires pre-existing ground reinforcement before the TBM arrives, resulting in limited construction space, numerous work procedures, high construction risks, long construction periods, and similarly high costs. Thirdly, using TBMs to open the tunnel and remove obstacles is often constrained in soft soil strata by earth pressure, groundwater, and surrounding rock stability. Even with reinforcement, it is difficult to safely open the tunnel for extended periods, and manual clearing carries significant risks and uncertainties. Fourth, some existing mechanical obstacle removal methods require the installation of large steel sleeves with a diameter of about 4m, and often require multiple holes to be arranged on both sides for obstacle removal. This not only places high demands on the ground and the construction surface inside the foundation pit, but also significantly extends the obstacle removal cycle due to the multiple hole construction, and the project cost also increases accordingly.

[0005] In engineering practice, there have been cases where tunnel boring machines (TBMs) have directly cut through existing diaphragm walls of railway stations. However, this approach mostly occurs when the joint is a lock-joint pipe or the diaphragm wall lacks steel reinforcement, meaning the obstacle is mainly concrete or ordinary steel reinforcement. With proper cutter configuration, controlled propulsion parameters, and local reinforcement in the crossing area, the TBM can complete the excavation within manageable risks. However, for diaphragm walls with internal steel joints, there is currently a lack of mature, economical, and site-adaptable clearing methods. This is because the strength and stiffness of steel joints are significantly higher than ordinary reinforced concrete. Direct cutting by the TBM could lead to severe cutter wear, frequent cutter replacements, and a sudden increase in propulsion torque. Furthermore, it could adversely affect the TBM's attitude and passing accuracy. If traditional large-scale excavation or large-diameter casing is used for clearing before the TBM arrives, it faces practical problems related to site availability, construction period, and high costs.

[0006] In conclusion, it is necessary to propose a shield tunneling construction scheme that enables targeted, mechanized, and low-risk obstacle removal of diaphragm walls with steel joints under site-constrained conditions. Summary of the Invention

[0007] This invention provides a mechanical obstacle removal method and system for shield tunneling through a steel joint underground continuous wall, aiming to solve the problems of large amount of obstacle removal work, high time cost, and high construction risk in the existing technology.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] In a first aspect, the present invention provides a mechanical obstacle removal method for shield tunneling through a diaphragm wall with a steel joint, comprising the following steps:

[0010] Based on the design shield axis of the newly built shield tunnel section and the plan position, burial depth and steel joint arrangement of the existing diaphragm wall, determine the positioning coordinates of the diaphragm wall section and the steel joints within the shield tunnel crossing range.

[0011] Vertical boreholes are set at the location to be cleared on the side of the underground continuous wall away from the foundation pit. A full-casing full-rotation drilling rig is used to drill, cut and remove the reinforced concrete and steel joints of the underground continuous wall in sections, and backfill the resulting vertical boreholes.

[0012] In the underground continuous wall, at the location to be cleared on the side adjacent to the foundation pit, horizontal or near-horizontal boreholes are arranged. Diamond drilling equipment is used to cut and remove the steel joints within the shield tunnel portal area of ​​the underground continuous wall, and the resulting horizontal clearing holes are sealed or backfilled.

[0013] After completing the vertical and horizontal obstacle removal, the tunnel boring machine will proceed with the construction of the tunnel through the diaphragm wall.

[0014] Furthermore, after determining the tunnel boring machine's crossing range, 2-3 interlocking plain concrete piles are constructed on the surface outside the existing diaphragm wall according to the vertical drilling and obstacle clearing positions. The concrete grade of the piles is consistent with that of the diaphragm wall.

[0015] Furthermore, before conducting vertical drilling to clear obstacles, vertical MJS method piles were constructed on the outer side of the underground continuous wall at the far end of the existing operating station to reinforce the weak strata, and vertical MJS method piles were also constructed at the joint of the underground continuous wall between the existing operating station and the new station to reinforce the joint strata.

[0016] Furthermore, the vertical drilling and obstacle removal is carried out using a full-casing full-rotation drilling rig, which is equipped with a full-alloy wear-resistant drill bit and an automatic verticality measurement and control system.

[0017] Furthermore, the vertical drilling for obstacle removal is carried out in sections of 5-6m, and the steel joints are twisted off and pulled out until the obstacle is removed to the designed depth. The vertical drilling holes are then backfilled with M30 mortar.

[0018] Furthermore, before conducting horizontal or near-horizontal drilling for obstacle removal, horizontal freezing or MJS method pile reinforcement is implemented from the new station foundation pit to the existing station below, in order to form a reinforced backing when the shield tunnel cuts the soil behind the underground continuous wall.

[0019] Furthermore, the horizontal or near-horizontal drilling for obstacle removal involves arranging a horizontal diamond drilling rig within the foundation pit of the newly built station to remove the steel joints of the underground continuous wall within the shield tunnel portal area from top to bottom. After each borehole is completed, it is backfilled with micro-expansion concrete of the same grade as the underground continuous wall.

[0020] Furthermore, when site conditions prevent vertical drilling to clear obstacles from the diaphragm wall on the side far from the pit, the vertical clearing step for the distant diaphragm wall is omitted. The tunnel boring machine (TBM) starts from the new station tunnel shaft near the existing station, and after excavating and cutting the first section of the diaphragm wall located near the pit and whose steel joints have been cleared by horizontal drilling, it continues to excavate and cut the second section of the diaphragm wall located far from the pit and containing steel joints. After cutting through the distant diaphragm wall, the TBM cutters are inspected and replaced in the pre-set cutter replacement and reinforcement area behind it, and then the remaining section is excavated.

[0021] Secondly, the present invention provides a mechanical obstacle clearing system for shield tunneling through a steel joint diaphragm wall, comprising:

[0022] A positioning unit is used to determine the section of diaphragm wall to be cleared and the steel joints within the shield tunneling area based on the design shield axis of the newly constructed shield tunnel section and the planar position, burial depth, and steel joint arrangement of the existing diaphragm wall; a vertical clearance unit is set on the side away from the pit for vertical drilling clearance of the diaphragm wall, the vertical clearance unit including a full-casing full-rotation drilling rig and a backfilling device for backfilling the vertical drilling clearance holes; a horizontal clearance unit is set on the side near the pit for horizontal or near-horizontal drilling clearance of the diaphragm wall, the horizontal clearance unit including a horizontal diamond drilling rig and a backfilling device for sealing or backfilling the horizontal clearance holes.

[0023] Furthermore, the vertical obstacle removal unit's full-casing full-rotation drilling rig is equipped with an all-alloy wear-resistant drill bit and an automatic verticality measurement and control device, used to realize the segmented drilling, segmented cutting, and extraction of the vertical borehole;

[0024] The horizontal obstacle removal unit is located in the foundation pit of the new station and includes an adjustable-angle drilling rig support frame, a horizontal diamond drilling equipment, and a micro-expansion concrete backfilling device with the same concrete grade as the existing underground continuous wall.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention addresses the scenario where a tunnel boring machine (TBM) needs to pass through a diaphragm wall containing steel joints. It involves setting up vertical boreholes on the side away from the pit and using a full-casing rotary drilling rig to remove the concrete and steel joints within the wall in sections. On the side near the pit, horizontal or near-horizontal boreholes are set up, and diamond drilling equipment is used to directionally remove the steel joints within the TBM portal area. This limits the clearing area to the wall section actually passed through by the TBM, eliminating the need for large-diameter clearing wells and localized underground excavation. The construction area is small, making it suitable for situations with limited space near stations.

[0027] In this embodiment of the invention, before vertical and horizontal drilling for obstacle removal, MJS method piles or horizontal reinforcement bodies are installed on the outside of the underground continuous wall and in the gap between the existing station and the new station. This can provide a stable backing for the soil behind the wall during obstacle removal and subsequent shield tunneling wall grinding and cutting processes, thereby reducing the impact on the existing structure and surrounding operating stations.

[0028] In this embodiment of the invention, for the diaphragm wall near the new station, the steel joints are removed by horizontal or near-horizontal drilling and backfilled in a timely manner with micro-expansion concrete of the same grade as the original diaphragm wall. This can restore local rigidity and water-stopping performance while clearing obstacles. For the steel joints in the diaphragm wall at the far end, the obstacles are removed by vertical drilling and backfilled with mortar of the same grade as the original diaphragm wall. This allows for segmented removal and restoration, with a clear construction sequence.

[0029] In embodiments of this invention, when on-site conditions prevent complete vertical obstacle removal, the invention provides a provision for a scenario where the tunnel boring machine (TBM) cuts through the far-end steel-jointed diaphragm wall, inspects and replaces the cutters within the reinforced area, and then proceeds to excavate the remaining section. This allows for the completion of TBM tunneling preparations without large-scale alteration of the existing retaining structure. Overall, this invention achieves targeted mechanical obstacle removal for diaphragm walls with steel joints without adding large casings or expanding the excavation, providing an feasible construction method for the TBM to pass along the designed axis.

[0030] Of course, implementing the various technical solutions of this invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the obstruction clearing and reinforcement of a shield tunnel through a steel joint underground continuous wall according to an embodiment of the present invention;

[0033] Figure 2 yes Figure 1 AA side section view;

[0034] Figure 3 This is a detailed schematic diagram of the obstacle clearing plan of a shield tunnel passing through a diaphragm wall according to an embodiment of the present invention;

[0035] Figure 4 This is an enlarged view of the vertical drilling obstacle removal in an embodiment of the present invention;

[0036] Figure 5 This is a schematic cross-sectional view of vertical drilling for obstacle removal according to an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of the horizontal drilling arrangement for obstacle removal according to an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of the steel joint for the underground continuous wall according to an embodiment of the present invention.

[0039] In the diagram, 1-existing diaphragm wall near the end, 2-existing diaphragm wall at the far end, 3-steel joint of diaphragm wall, 4-new station foundation pit, 5-existing station, 6-vertical MJS method pile reinforcement zone, 7-horizontal MJS method pile reinforcement zone, 8-slit MJS method pile reinforcement zone, 9-plain concrete cast-in-place pile, 10-full casing full-rotation drilling rig, 11-existing station lattice column, 12-existing station column pile, 13-horizontal or near-horizontal borehole. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0041] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0042] Example 1:

[0043] This embodiment provides a mechanical obstacle removal method for shield tunneling through diaphragm walls with steel joints. It is applicable to situations where a newly constructed shield tunnel section needs to pass through two existing diaphragm walls from the foundation pit on one side of an existing station, and both diaphragm walls contain diaphragm wall steel joints 3. See also... Figures 1-7 The specific steps of the method in this embodiment are as follows:

[0044] Step S1: Determine the scope of obstacle removal: such as Figure 1 As shown, based on the positional relationship between the shield tunnel axis and the new station pit 4 in the design of the new shield tunnel section, it is determined that the shield will sequentially pass through the existing diaphragm wall 1 near the pit and the existing diaphragm wall 2 far from the pit. Combining the arrangement of the diaphragm wall steel joints 3 in the existing engineering data, the wall sections falling within the shield's outer diameter and portal height range are identified as the sections to be cleared, with the diaphragm wall steel joints 3 being the primary targets for removal. The purpose of this step is to limit the clearing scope to the wall sections that the shield must pass through, avoiding ineffective demolition and alteration of the retaining structure in non-passing areas.

[0045] Step S2, reinforcement of soil and back wall in the crossing area: such as Figure 1 and Figure 2 As shown, to ensure the stability of subsequent drilling and shield tunneling wall construction, a vertical MJS pile reinforcement zone 6 is arranged outside the existing diaphragm wall 2 at the far end to reinforce the weak soil behind the wall; a horizontal MJS pile reinforcement zone 7 is arranged below the existing diaphragm wall 1 at the near end and within the shield tunnel area; and a jointed MJS pile reinforcement zone 8 is arranged between the existing diaphragm wall 1 at the near end and the existing diaphragm wall 2 at the far end, and on the side close to the new station pit 4, to improve the integrity and anti-disturbance capacity of the jointed soil. These three types of reinforcement arrangements can provide reliable backing during subsequent vertical drilling, horizontal drilling, and shield machine cutting of the remaining wall, reducing the impact on the existing station 5 and its substructure (such as...). Figure 1 and Figure 2 The adverse effects of existing station grid columns 11 and existing station column piles 12.

[0046] Step S3, Construction of the vertical drilling platform and guide structure: (e.g.) Figure 1As shown, several plain concrete piles 9 are constructed above the existing underground continuous wall 2 at the ground position corresponding to the location of the proposed vertical drilling hole. The concrete grade of the plain concrete piles 9 is consistent with that of the existing underground continuous wall, and is used to form the landing and guiding foundation for the vertical drilling rig. This step can be selected and implemented according to the on-site working face and equipment stability requirements.

[0047] Step S4: Clearing obstructions by vertical drilling of the existing diaphragm wall at the far end: such as... Figure 4 and Figure 5 As shown, at the location of the vertical drilling clearance hole set on the existing underground continuous wall 2 at the far end, a full-casing full-rotation drilling rig 10 is placed to penetrate the concrete of the wall from top to bottom and drill to the depth where the underground continuous wall steel joint 3 is located. During the drilling process, the drilling is carried out in sections of 5-6m, and the underground continuous wall steel joint 3 to be cut off and the concrete of the same section are pulled out in sequence until the designed clearance depth is reached.

[0048] Step S5: Backfilling of Vertical Drilling Holes: After the vertical drilling is completed, the holes formed by the vertical drilling are backfilled with mortar of the same grade as the existing diaphragm wall. This ensures that the cleared area still has basic filling and water-stopping capabilities after the removal of the diaphragm wall steel joint 3, so that no obvious voids or leaks appear in the wall when the shield tunnel passes through.

[0049] Step S6: Horizontal drilling and obstacle removal near the existing diaphragm wall: such as Figure 3 and Figure 6 As shown, a horizontal diamond drilling rig is arranged in the foundation pit 4 of the new station, with the drilling direction pointing towards the location of the steel joint 3 of the existing underground continuous wall 1 that needs to be cleared. Multiple horizontal or near-horizontal boreholes 13 are arranged according to the height and width of the shield tunnel portal, so that the drilling trajectory of each borehole passes through the steel joint 3 of the underground continuous wall or the dense reinforcement on both sides. The diamond drilling equipment is used to cut or break the above-mentioned components, and the cut steel sections are taken out to form a clearance area that matches the outer contour of the shield.

[0050] Step S7, Backfilling of Horizontal Boreholes: After the horizontal boreholes are cleared, in order to restore the local integrity and waterproof performance of the existing underground continuous wall 1 at the near end, the horizontal boreholes that have been cleared are backfilled or sealed with micro-expansion concrete of the same grade as the wall concrete.

[0051] Step S8, Shield Tunneling and Residual Component Handling: After completing the vertical drilling and obstacle removal of the existing diaphragm wall 2 at the far end and the horizontal drilling and obstacle removal of the existing diaphragm wall 1 at the near end, and after the vertical MJS pile reinforcement zone 6, the horizontal MJS pile reinforcement zone 7, and the joint MJS pile reinforcement zone 8 have reached their design strength, the shield machine is launched from the shield launching shaft according to the designed shield advancement sequence. After tunneling to the cutterhead replacement and maintenance area in front of the existing station's far-end diaphragm wall, the cutters are replaced with cutters suitable for cutting reinforced concrete walls. After cutting the existing diaphragm wall 2 at the far end and the remaining steel sections, the shield machine passes through the existing station and continues... After cutting through the existing diaphragm wall 1 at the near end, the tunnel boring machine (TBM) enters the shield shaft of the new station to receive the equipment. If, due to site conditions, it is not possible to vertically drill and clear all the steel joints 3 of the existing diaphragm wall 2 at the far end, the TBM will start from the shield shaft of the new station near the existing station, excavate and cut through the first existing diaphragm wall 1 at the near end (the steel has been cleared by the horizontal drilling rig), pass under the existing station, and then continue cutting through the second existing diaphragm wall 2 at the far end. After passing through, the TBM will inspect and replace the cutting tools after cutting the steel wall in the tool replacement and reinforcement area set behind the far end wall, and continue to excavate the remaining section.

[0052] As can be seen from the above embodiments, this method takes two existing diaphragm walls as the target and adopts separate treatment methods of vertical drilling for obstacle removal (far end) and horizontal drilling for obstacle removal (near end). Combined with the vertical MJS method pile reinforcement zone 6, the horizontal MJS method pile reinforcement zone 7 and the inter-slot MJS method pile reinforcement zone 8, the obstacle removal range is consistent with the actual tunneling range of the shield. Without setting up large-diameter obstacle removal wells or excavating underground tunnels, the mechanized removal of the steel joints 3 of the diaphragm wall is completed before the shield tunneling. Moreover, the impact on the existing station 5 and its existing station lattice columns 11 is small, which meets the construction conditions of limited space and high construction period requirements near urban subway stations.

[0053] Example 2:

[0054] Correspondingly, this embodiment provides a mechanical obstacle removal system for shield tunneling through steel joint diaphragm walls, used in conjunction with the aforementioned method to complete the processes of obstacle removal range determination, far-end vertical obstacle removal, near-end horizontal obstacle removal, and obstacle removal hole backfilling in a mechanized manner.

[0055] The mechanical obstacle removal system first includes a positioning unit for determining the obstacle removal location. Based on the design shield axis of the newly constructed tunnel section, the planar position and depth data of the existing diaphragm wall, and the vertical and horizontal arrangement information of the diaphragm wall steel joints, the positioning unit determines the wall sections that need to be removed within the actual tunneling range, and identifies the steel joints within them as obstacles. This unit limits the subsequent drilling and obstacle removal location to the wall area that the shield must pass through, avoiding ineffective construction in non-tunneling areas.

[0056] The system also includes a vertical clearance unit for drilling and clearing obstacles from the diaphragm wall on the side furthest from the excavation pit. This unit is located on the ground or working platform near the far end of the diaphragm wall and uses a full-casing, full-rotation drilling rig as the main operating equipment. The rig is equipped with wear-resistant drill bits and an automatic verticality measurement and control device, allowing it to penetrate the concrete of the diaphragm wall from top to bottom and drill to the depth where the steel joints are located. It drills in sections according to a predetermined length, cuts sections, and removes the dismantled steel joints and concrete blocks. After vertical clearance is completed, the unit continues to inject mortar of the same or similar strength grade as the diaphragm wall into the borehole to backfill it, restoring the local integrity and waterproofing performance of the wall, thus ensuring that the wall will not develop significant voids due to clearance when the tunnel boring machine passes through.

[0057] The system also includes a horizontal obstacle removal unit for drilling horizontally or near-horizontally to remove obstacles from the diaphragm wall adjacent to the excavation pit. This unit is located inside the new station or working excavation pit and uses a horizontal diamond drilling rig as the main operating equipment. The rig, through adjustable supports or guide mechanisms, is aligned with the wall within the shield tunnel portal area, and several horizontal or near-horizontal boreholes are drilled according to the portal height and width. The drilling trajectory passes through the previously installed steel joints or reinforced steel bars in the wall, thereby achieving the cutting, breaking, and removal of these obstructing components. After horizontal obstacle removal is completed, the unit can also inject micro-expansion concrete or other compatible materials of the same grade as the wall into the boreholes to promptly seal the cleared channels, ensuring that the wall retains basic rigidity and water-stopping capabilities even after partial relocation.

[0058] In practical use, the mechanical obstacle removal system of this embodiment operates according to the following logic: First, the positioning unit outputs the planar position and depth control requirements of the obstacle removal hole; then, the vertical obstacle removal unit is activated to drill and backfill the steel joints in the diaphragm wall located within the shield tunneling range in sections; next, the horizontal obstacle removal unit is activated to drill and backfill the steel joints and reinforced steel bars in the diaphragm wall near the excavation pit that affect the passage of the shield tunnel portal; finally, the processed wall section is handed over to the shield tunneling, and the shield can then pass through the reinforced soil. This embodiment maps the key processes in the method to specific equipment units, with clear equipment types and fixed layout positions. It can be directly configured and used under the limited space conditions of subway stations, without the need for large-diameter obstacle removal wells or underground excavation operations, thus simplifying the construction organization.

[0059] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A mechanical obstacle removal method for shield tunneling through a steel-jointed diaphragm wall, characterized in that, Includes the following steps: Based on the design shield axis of the newly built shield tunnel section and the plan position, burial depth and steel joint arrangement of the existing diaphragm wall, determine the positioning coordinates of the diaphragm wall section and the steel joints within the shield tunnel crossing range. Vertical boreholes are set at the location to be cleared on the side of the underground continuous wall away from the foundation pit. A full-casing full-rotation drilling rig is used to drill, cut and remove the reinforced concrete and steel joints of the underground continuous wall in sections, and backfill the resulting vertical boreholes. In the underground continuous wall, at the location to be cleared on the side adjacent to the foundation pit, horizontal or near-horizontal boreholes are arranged. Diamond drilling equipment is used to cut and remove the steel joints within the shield tunnel portal area of ​​the underground continuous wall, and the resulting horizontal clearing holes are sealed or backfilled. After completing the vertical drilling and horizontal obstacle removal, the tunnel boring machine will proceed with the tunneling through the diaphragm wall. After determining the tunnel boring machine's crossing range, 2-3 interlocking plain concrete piles are constructed on the surface outside the existing diaphragm wall according to the vertical drilling and obstacle clearing location. The concrete grade of the piles is consistent with that of the diaphragm wall. Before carrying out vertical drilling to clear obstacles, vertical MJS method piles were constructed on the outside of the underground continuous wall at the far end of the existing operating station to reinforce the weak strata, and vertical MJS method piles were constructed at the joint of the underground continuous wall between the existing operating station and the new station to reinforce the joint strata. The vertical drilling for obstacle removal is carried out in sections of 5-6m, and the steel joints are twisted off and pulled out until the obstacle is removed to the designed depth. The vertical drilling for obstacle removal is then backfilled with M30 mortar. Before conducting horizontal or near-horizontal drilling for obstacle removal, horizontal freezing or MJS method pile reinforcement is carried out from the new station foundation pit to the existing station to form a reinforced backing when the shield tunnel cuts the soil behind the underground continuous wall.

2. The mechanical obstacle removal method for shield tunneling through a steel joint diaphragm wall according to claim 1, characterized in that, The vertical drilling and obstacle removal is carried out using a full-casing full-rotation drilling rig, which is equipped with a full-alloy wear-resistant drill bit and an automatic verticality measurement and control system.

3. The mechanical obstacle removal method for shield tunneling through a steel joint diaphragm wall according to claim 1, characterized in that, The horizontal or near-horizontal drilling for obstacle removal involves deploying a horizontal diamond drilling rig within the foundation pit of the new station to remove the steel joints of the underground continuous wall within the shield tunnel portal area from top to bottom. After each borehole is completed, it is backfilled with micro-expansion concrete of the same grade as the underground continuous wall.

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