Shield tunnel deformation overrun correction pile group and correction method

Abstract

The invention belongs to the technical field of shield tunnel construction, and discloses a shield tunnel deformation overrun correction pile group and a correction method. The correcting method comprises the following steps that (1) a high-pressure jet grouting method is adopted, grouting is conducted on a soil layer outside a single segment with deformation exceeding the limit to form a pile column on the outer circle face of the segment, the grouting pressure in the grouting process acts on the segment through the soil layer outside the segment, and therefore correcting pressure for correcting deformation of the segment with deformation exceeding the limit is generated; the correction pressure acting on the duct piece is adjusted by adjusting the grouting pressure and / or the slurry return pressure; and (2) the step (1) is repeated till correction of all the segments, with deformation exceeding the limit, of the shield tunnel is completed. The radial piles are formed on the outer side of the tunnel through the high-pressure jet grouting technology, the soil property around the tunnel is improved, meanwhile, the size of the correction force is controlled by controlling the slurry return pressure in the jet grouting process, accurate correction of the deformation over-limit shield tunnel is achieved, and the operation safety of the shield tunnel is effectively guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of shield tunnel construction technology, and more specifically, relates to a shield tunnel deformation over-limit correction pile group and correction method. Background Art

[0002] During long-term operation, shield tunnels face many complex environmental factors, leading to increasingly prominent structural deformation problems and posing a serious threat to the safe operation of urban rail transit.

[0003] Tunnel convergence deformation refers to the uneven changes in the lateral or longitudinal geometry of a tunnel during its use after construction. This deformation is usually caused by a variety of factors, such as tunnel structural design, geological conditions, and construction methods.

[0004] Deformation of shield tunnels includes uplift, uneven settlement, and lateral convergence deformation. Uplift can cause problems such as encroachment, misalignment, cracking, and water leakage, and in severe cases, structural damage. Uneven settlement can cause tunnel alignment to bend, affecting train safety. Lateral convergence deformation refers to changes in the tunnel's lateral dimensions after construction. These changes are usually caused by construction errors, shield tunnel assembly, and other factors.

[0005] The causes of excessive deformation in shield tunnels are complex and varied. Soil loss and disturbance are significant factors. During shield tunnel construction, some degree of damage and disturbance to the surrounding soil is inevitable, leading to soil erosion and loss of the tunnel's original soil support balance, thus triggering structural deformation. For example, in soft soil strata, the soil's high fluidity makes soil loss more likely, causing uneven pressure on the tunnel segments and resulting in convergence deformation. Furthermore, external engineering activities also significantly impact the structural stability of shield tunnels. During urban underground space development, frequent construction activities such as foundation work on surrounding buildings, laying underground pipelines, and road excavation can alter the stress distribution around the shield tunnel, increasing the complexity of the tunnel structure and inducing deformation. For instance, deep foundation pit excavation near the shield tunnel can cause a drop in the surrounding groundwater level due to dewatering, leading to soil consolidation and volume shrinkage, resulting in uneven compression of the tunnel and causing convergence deformation. Furthermore, the natural changes in groundwater level cannot be ignored. Long-term decline or rise in groundwater level will change the physical and mechanical properties of the soil, affect the interaction between the shield tunnel and the surrounding soil, and thus lead to deformation of the tunnel structure.

[0006] Long-term cyclical train loads are also a significant factor contributing to shield tunnel deformation. The frequent operation of urban rail transit trains exerts continuous dynamic loads on the tunnel structure. During operation, the vibration loads generated by the interaction between the train wheels and rails are constantly transmitted to the tunnel segments. Over many years, this cumulative effect gradually causes fatigue damage to the segments, reducing the overall stiffness and load-bearing capacity of the tunnel structure, thus promoting deformation. This is especially true in curved tunnels or sections with high train speeds, where the centrifugal force and impact force generated by passing trains are greater, further exacerbating tunnel convergence deformation.

[0007] Faced with the serious problem of excessive deformation in shield tunnels, existing remedial methods have many limitations. A common approach to addressing excessive settlement in shield tunnels is micro-disturbance dual-liquid grouting within the tunnel. The basic principle is to inject a dual-liquid grout into the surrounding soil inside the tunnel to fill voids, enhance soil strength, and thus control settlement. However, this micro-disturbance grouting method has significant shortcomings. First, its effect on improving the soil beneath the tunnel is very limited, failing to effectively increase the soil's bearing capacity and resulting in poor settlement control. Second, the injected dual-liquid grout has poor durability; under long-term exposure to groundwater and train loads, it is prone to aging and strength reduction, making it difficult to maintain effective control over tunnel settlement in the long term. More seriously, if the grouting pressure is improperly controlled and exceeds the soil's bearing capacity, it can disturb the original stress state of the soil beneath the tunnel, inducing secondary settlement and further exacerbating tunnel deformation, posing a greater threat to tunnel structural safety.

[0008] Regarding the issue of excessive elliptic deformation in shield tunnels, the common current solution is to reinforce the tunnel with steel rings. This method involves stacking a steel plate approximately 2cm thick inside the tunnel to increase its circumferential stiffness and thus resist elliptic deformation. However, practical application and research have revealed several drawbacks to steel ring reinforcement. Firstly, the steel rings have poor durability. Under long-term groundwater corrosion and train vibration loads, the material properties of the steel rings gradually degrade, reducing their corrosion resistance and mechanical properties, thus losing their effective reinforcement function for the tunnel structure and posing a potential threat to tunnel safety. Secondly, while steel ring reinforcement can improve the circumferential stiffness of the tunnel to some extent, it only provides localized strengthening of the internal structure and does not fundamentally solve the soil imbalance problem that causes tunnel elliptic deformation. It cannot completely eradicate the elliptic deformation phenomenon, meaning that tunnel deformation may reappear after a period of reinforcement. Summary of the Invention

[0009] In response to the above-mentioned defects or improvement needs of existing technologies, this invention provides a method for correcting excessive deformation in shield tunnels, pile columns, pile groups, and a construction method for pile groups. It corrects the tunnel segments by generating corrective forces during grouting construction, and the resulting pile columns can improve the surrounding soil, effectively solving the problem of excessive deformation in shield tunnels in the long term. The cost is lower than that of traditional micro-disturbance grouting and steel ring reinforcement.

[0010] To achieve the above objectives, according to one aspect of the present invention, a method for correcting excessive deformation in a shield tunnel is provided, comprising the following steps: 1) High-pressure jet grouting is used to inject grout into the soil layer outside the individual segment with excessive deformation to form a pile column on the outer circumference of the segment. The grouting pressure during the grouting process acts on the segment through the soil layer outside the segment, thereby generating a corrective pressure on the segment to correct the excessive deformation of the segment, thus achieving the correction of the excessive deformation of the individual segment; wherein, the center line of the formed pile column intersects with the center line of the segment, and the corrective pressure acting on the segment is adjusted by adjusting the grouting pressure and / or the return grouting pressure; 2) Repeat step 1) until all segments of the shield tunnel that have exceeded the deformation limit have been corrected. In this way, the excessive deformation of the shield tunnel can be corrected.

[0011] Preferably, among the multiple piles formed in step 2), there are horizontal piles, so that during the process of forming horizontal piles by grouting, a corrective pressure is generated on the tunnel segment to correct the lateral convergence deformation of the tunnel segment, thereby realizing the correction of the excessive lateral convergence deformation of the shield tunnel. and / or; Step 2) involves the formation of multiple piles, including vertical piles. During the grouting process to form these vertical piles, corrective pressure is generated on the tunnel segments to correct any upward movement or uneven settlement of the segments, thereby correcting any upward movement or uneven settlement of the shield tunnel. Specifically, when correcting the upward movement of the shield tunnel, the vertical piles are located above the shield tunnel; when correcting the uneven settlement of the shield tunnel, the vertical piles are located below the shield tunnel. and / or; Step 2) Among the multiple piles formed, there are piles that are inclined relative to the vertical plane. During the process of grouting to form piles that are inclined relative to the vertical plane, a supporting force is generated on the tunnel segment to provide oblique support for the tunnel segment, thereby achieving oblique support for the shield tunnel.

[0012] Preferably, in step 1), before grouting using the high-pressure jet grouting method, the service status of the shield tunnel is first determined based on the monitored segment deformation data, and then the correction target for segments with excessive deformation is set according to the service status of the shield tunnel. Finally, the design scheme and construction procedure of the pile group are determined, wherein the pile group is a spatial combination of piles on the outer circular surface of the shield tunnel.

[0013] Preferably, in step 1), the method for controlling the grouting pressure is as follows: 1a) After grouting the soil layer for a set time using the set grouting pressure and return pressure, measure the displacement of the sidewall of the segment; 1b) Compare the measured value of the segment sidewall displacement with the target value of the segment sidewall displacement. If the measured value is less than the target value, increase the set grouting pressure and / or decrease the return grouting pressure, and then return to step 1a; if it is not less than the target value, continue grouting according to the grouting pressure set in step 1a.

[0014] Preferably, in step 2), only one pile is grouted at a time to form a pile column, and a batch of vertical pile columns are formed by grouting sequentially according to the construction sequence, and the first pile column is... i The second grouting is used to correct floating or uneven settlement of the segments. i Vertical displacement of a single tunnel segment δ i The calculation method is as follows: δ i = δ ii + δ ji ; in, δ i For the first i The total vertical correction amount for each segment, in meters; δ ii For the first i The vertical correction amount of each segment during grouting is expressed in meters (m). δ ji For the first j When grouting the first segment, the first i Vertical correction amount for each segment, in meters. j The first segment and the first i Each segment is a different segment, and: ; c i For the first i The other pipe segments next to the first pipe segment are related to the first... i Constraint influence coefficient of each tunnel segment; Δ P i For the first i The correction pressure on each segment is expressed in MPa, and Δ P i = P i ×β , P i For the first i Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; A 1i To correct the pressure acting on the first i The effective working area per meter of the reinforced body of each segment, in m², wherein the reinforced body is the end of the pile that contacts the segment and is the thickened end; K vi For the first i The soil reaction coefficient next to each tunnel segment, in kN / m³; e i For the first i The compaction coefficient between each pipe segment and the soil; A 2i The effective working area of ​​the soil on the side of the shield tunnel opposite to the pile is measured in m². ; δ jj For the first j The vertical correction amount of each segment grouting itself, in meters; d ji = L ji + L 0 ,in L ji For the first j The first segment and the first i The distance between each segment L 0 The axial length of a single segment. d ji , L ji and L 0 The unit is m, the first j The first segment and the first i Each segment is a different segment; k This is the attenuation factor, with a value ranging from 1 to 2; n Other factors may affect the first step during grouting. i The total number of segments whose vertical correction is required; c j For the firstj The other pipe segments next to the first pipe segment are related to the first... j Constraint influence coefficient of each tunnel segment; Δ P j For the first j The correction pressure on each segment is expressed in MPa, and Δ P j = P j × β , P j For the first j Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; A 1j To correct the pressure acting on the first j The effective working area per meter of the reinforced body of each segment, in m², wherein the reinforced body is the end of the pile that contacts the segment and is the thickened end; K vj For the first j The soil reaction coefficient next to each tunnel segment, in kN / m³; e j For the first j The compaction coefficient between each pipe segment and the soil; A 2j It represents the effective working area of ​​the soil per meter on the side of the shield tunnel opposite to the pile, expressed in m².

[0015] Preferably, in step 2), each grouting operation forms only one pile column, and grouting is performed sequentially according to the construction sequence to form a batch of horizontal pile columns, and the first... i The segment for which lateral convergence correction was performed during the second grouting was the first... i The first segment, then the second i Total correction amount of lateral convergence for each segment S i The calculation method is as follows: S i = S ii + S ji ; S ii For the first i The lateral convergence correction amount of each segment during grouting is expressed in meters. S ji For the first jWhen grouting the first segment, the first i The lateral convergence correction amount for each segment, in meters, is... j The first segment and the first i Each segment is a different segment; ; Δ P i For the first i The correction pressure on each segment is expressed in MPa, and Δ P i = P i × β , P i For the first i Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; e i For the first i The compaction coefficient between each pipe segment and the soil; R i = r i + t / 2, in meters, and r i For the first i The inner diameter of each segment, t For the first i The horizontal thickness of each segment; v ci For the first i Poisson's ratio of concrete for each tunnel segment; E ci For the first i The elastic modulus of concrete for each segment, in MPa; b i For the first i The thickness of each segment in the horizontal direction is expressed in meters (m). f i For the first i Stiffness reduction factor for each tunnel segment; ; S jj For the first j The lateral convergence correction amount of each segment grouting is expressed in meters. d ji =L ji + L 0 ,in L ji For the first j The first segment and the first i The distance between each segment L 0 The axial length of a single segment. d ji , L ji and L 0 The unit is m, the first j The first segment and the first i Each segment is a different segment; Δ P j For the first j The correction pressure on each segment is expressed in MPa, and Δ P j = P j × β , P j For the first j Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; e j For the first j The compaction coefficient between each pipe segment and the soil; R j For the first j The horizontal inner diameter of each segment, in meters; v cj For the first j Poisson's ratio of concrete for each tunnel segment; E cj For the first j The elastic modulus of concrete for each segment, in MPa; b j For the first j The thickness of each segment in the horizontal direction is expressed in meters (m). f j For the first j Stiffness reduction factor for each tunnel segment; k This is the attenuation factor, with a value ranging from 1 to 2; N Other factors may affect the first step during grouting.i The total number of segments requiring horizontal correction.

[0016] Preferably, step 2) specifically includes the following sub-steps: 2.1) Construction shall form all horizontal piles, and during the construction of the horizontal piles, except for the first horizontal piles, the construction of other horizontal piles shall be carried out in the following manner: the horizontal piles constructed in this construction shall be spaced 4 to 5 segments apart from the horizontal piles constructed in the previous construction. 2.2) Construction shall form all vertical piles, and during the construction of the vertical piles, except for the first vertical piles, the construction of the other vertical piles shall be carried out in the following manner: the vertical piles constructed this time shall be spaced 4 to 5 segments apart from the vertical piles constructed last time.

[0017] Preferably, step 2) further includes the following sub-steps: 2.3) Construct all inclined piles, and during the construction of inclined piles, except for the inclined piles constructed in the first construction, the construction of other inclined piles shall be carried out in the following manner: the inclined piles constructed in this construction shall be spaced 4 to 5 segments apart from the inclined piles constructed in the previous construction.

[0018] According to another aspect of the present invention, a shield tunnel deformation over-limit correction pile group is also provided, comprising multiple pile columns, which are formed after the shield tunnel is corrected using the correction method described above.

[0019] Preferably, the pile group includes multiple sets of first pile groups, wherein: Each first pile group includes horizontal piles and vertical piles, with the horizontal piles and vertical piles being horizontal piles and vertical piles, respectively. The first pile group in each group consists of two horizontal piles and one vertical pile, and the centerlines of the two horizontal piles and the one vertical pile are coplanar; The two horizontal piles of the first pile group in each group are symmetrically arranged on the segment, and the two horizontal piles and one vertical pile of the first pile group in each group are installed on the same segment of the shield tunnel. Any two adjacent groups of first pile columns are spaced apart by at least one segment.

[0020] Preferably, the pile group includes multiple sets of second pile groups, wherein: Each second pile group includes horizontal piles and vertical piles, with the horizontal piles and vertical piles being horizontal piles and vertical piles, respectively. The second pile group in each group consists of two horizontal piles and one vertical pile; Each second pile group also includes two inclined piles and a vertical pile located between the two inclined piles; The two inclined piles of the second pile group in each group are arranged symmetrically on the segments; The centerlines of the two inclined piles, one vertical pile, and two horizontal piles in the second pile group of each group are coplanar; The two horizontal piles of the second pile group are arranged symmetrically. The two inclined piles, one vertical pile and two horizontal piles of each second pile group are installed on the same segment of the shield tunnel. Any two adjacent second pile groups are arranged with at least one segment between them.

[0021] Preferably, the pile group includes multiple sets of third pile groups, wherein: Each group of the third pile column includes horizontal pile columns and vertical pile columns, which are horizontal piles and vertical pile columns respectively. Each group of the third pile group consists of one horizontal pile and one vertical pile; Each group of the third pile column also includes a pile column whose center line is inclined relative to the vertical plane. The pile column whose center line is inclined relative to the vertical plane is an inclined pile, and there is one inclined pile. The centerlines of one inclined pile, one vertical pile, and one horizontal pile in the third pile group of each group are coplanar; One horizontal pile, one vertical pile, and one inclined pile of the third pile group in each group are installed on the same segment; For any two adjacent sets of third pile groups, the projections of the two inclined piles on the cross-section of the pipe segment are symmetrical, and the projections of the two horizontal piles on the cross-section of the pipe segment are also symmetrical.

[0022] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1) The shield tunnel deformation over-limit correction method of the present invention forms a pile by grouting into the soil layer outside the individual segment with excessive deformation. The grouting pressure is converted into correction pressure and acts directly on the segment to achieve precise correction of the deformation of the individual segment. Compared with the traditional method of using piles for overall reinforcement, it is more targeted, can accurately correct deformation, and effectively solve the deformation problem of shield tunnels.

[0023] 2) The shield tunnel deformation over-limit correction method of the present invention, by correcting the segments one by one, not only ensures that each segment can be fully corrected, but also facilitates quality control and progress management during construction, effectively improves construction efficiency, and ensures that the deformation of the entire shield tunnel is comprehensively and systematically corrected.

[0024] 3) The shield tunnel deformation over-limit correction method of the present invention not only generates correction pressure on the tunnel segments during the grouting process, but also allows the cement grout to penetrate and solidify the soil layer outside the tunnel segments to form piles, thereby improving the physical and mechanical properties of the surrounding soil, increasing the strength and stability of the soil, providing more solid external support for the tunnel segments, reducing the impact of soil deformation on the tunnel segments, enhancing the overall stability of the tunnel, fundamentally solving the problem of shield tunnel convergence deformation caused by insufficient soil support, with more durable and reliable effects, effectively extending the service life of the tunnel, and reducing the later maintenance costs and frequency.

[0025] 4) The shield tunnel deformation over-limit correction method of the present invention can easily adjust the magnitude and duration of the correction pressure by controlling parameters such as grouting pressure, so as to adapt to the needs of different segment deformation degrees and geological conditions. The construction process is highly flexible and can be dynamically adjusted according to the actual situation to ensure that the correction effect meets the design requirements.

[0026] 5) The shield tunnel deformation over-limit correction method of the present invention can improve the surrounding soil and solve the problem of shield tunnel deformation over-limit in a long term. From the perspective of the whole life cycle, the cost is reduced by 30% compared with traditional micro-disturbance grouting and steel ring reinforcement, filling the gap in the industry for efficient correction technology.

[0027] 6) The pile group for the convergence deformation correction of shield tunnels of the present invention adopts a combination of horizontal piles, vertical piles and inclined piles, which combines the spatial pile group with the stratum reinforcement of shield tunnel, breaks through the limitations of traditional single-point reinforcement, and performs both correction and reinforcement of shield tunnel simultaneously. Attached Figure Description

[0028] Figure 1 This is a schematic diagram showing the installation of two horizontal piles on the tunnel lining segments according to the present invention. Figure 2 This is a schematic diagram showing the installation of two horizontal piles and two inclined piles on the tunnel lining segments according to the present invention. Figure 3 This is a schematic diagram showing the installation of two horizontal piles and one vertical pile on the tunnel lining segment according to the present invention. Figure 4 This is a construction sequence diagram for horizontal and vertical piles in a shield tunnel according to the present invention. Figure 5 This is a schematic diagram showing the installation of two horizontal piles, one vertical pile, and two inclined piles on the tunnel lining segments of the present invention. Figure 6 This is a construction sequence diagram of horizontal piles, vertical piles, and inclined piles in one of the layouts for shield tunneling according to the present invention; Figure 7 This is a schematic diagram showing the installation of a horizontal pile, a vertical pile, and an inclined pile on the tunnel lining segment of the present invention. Figure 8This is a construction sequence diagram of horizontal piles, vertical piles, and inclined piles in another layout for shield tunneling according to the present invention. Figure 9 This is a schematic diagram of constructing piles with enlarged ends on the pipe segments of the present invention; Figure 10 This is a process flow diagram of the TJS method for constructing pile columns according to the present invention.

[0029] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. Shield tunnel; 11. Segment; 2. Horizontal pile; 3. Vertical pile; 4. Inclined pile; 5. Reinforced body; 6. Enlarged end. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Reference Figures 1-9 According to one aspect of the present invention, a method for correcting convergence deformation of a shield tunnel is provided, comprising the following steps: 1) High-pressure jet grouting is used to inject grout into the soil layer outside individual segments 11 of the shield tunnel 1 to form piles on the outer surface of segments 11. During the grouting process, the grouting pressure acts on segments 11 through the soil layer outside the segments 11, thereby generating corrective pressure on segments 11 to correct their deformation, thus achieving the correction of deformation of individual segments 11. High-pressure jet grouting (also called high-pressure rotary jet grouting) can be performed using the MJS method, TJS method, or other high-pressure jet grouting methods.

[0032] 2) Repeat step 1) until all the segments 11 of the shield tunnel that have exceeded the deformation limit have been corrected. In this way, the deformation of the shield tunnel 1 is corrected.

[0033] The shield tunnel 1 is assembled from segments 11. By correcting the deformation of each individual segment 11 that exceeds the limit, the present invention can correct the deformation of the entire shield tunnel 1.

[0034] Furthermore, in step 2), among the multiple piles formed, there are horizontal piles. During the process of forming horizontal piles through grouting, a corrective pressure is generated on the segment 11 to correct the lateral convergence deformation of the segment 11, thereby achieving the correction of the excessive lateral convergence deformation of the segment 11. and / or; In step 2), among the multiple piles formed, there are vertical piles. During the process of grouting to form vertical piles, corrective pressure is generated on the tunnel segment 11 to correct the floating or uneven settlement of the tunnel segment 11, thereby correcting the floating or uneven settlement of the shield tunnel 1. When correcting the floating of the shield tunnel 1, the vertical piles are located above the shield tunnel 1, and when correcting the uneven settlement of the shield tunnel 1, the vertical piles are located below the shield tunnel 1.

[0035] and / or; In step 2), among the multiple piles formed, there are piles that are inclined relative to the vertical plane. During the process of grouting to form piles that are inclined relative to the vertical plane, a supporting force is generated on the segment 11 to provide oblique support for the segment 11, thereby achieving oblique support for the shield tunnel 1.

[0036] The construction method for forming horizontal piles is as follows: 1.1) High-pressure jet grouting is used to inject grout into the soil layer outside the individual segments 11 of the shield tunnel 1 to form horizontal piles on the outer circular surface of the segments 11. The grouting pressure during the grouting process acts on the segments 11 through the soil layer outside the segments 11, thereby generating a corrective pressure on the segments 11 to correct the deformation of the segments 11, and thus achieving the correction of the excessive lateral convergence deformation of the shield tunnel 1.

[0037] 2.1) Repeat step 1.1) until the horizontal deformation of all the segments 11 is corrected. In this way, the lateral convergence deformation of the shield 1 is corrected.

[0038] The construction method for forming vertical piles is as follows: 1.1.1) High-pressure jet grouting is used to inject grout into the soil layer outside the individual segments 11 of the shield tunnel 1 to form vertical piles on the outer surface of the segments 11. The grouting pressure during the grouting process acts on the segments 11 through the soil layer outside the segments 11, thereby generating corrective pressure on the segments 11 to correct the floating or settlement of the segments 11, and thus correcting the floating or uneven settlement of the shield tunnel 1. When correcting the floating of the shield tunnel 1, the vertical piles are located above the shield tunnel 1; when correcting the uneven settlement of the shield tunnel 1, the vertical piles are located below the shield tunnel 1.

[0039] 2.1.1) Repeat step 1.1.1) until the upward or downward correction of all the segments 11 is completed. In this way, the upward or uneven settlement of the shield tunnel 1 is corrected.

[0040] By grouting the soil layer outside segment 11 to form vertical piles, the corrective pressure generated by the grouting pressure can precisely correct the uplift or settlement of a single segment 11. For the uplift of shield tunnel 1, the vertical piles formed above generate downward pressure for correction; for settlement, the vertical piles formed below generate upward lifting force for correction. This targeted vertical correction method can effectively solve the problems of uplift or uneven settlement of segment 11, restore the normal axial position and elevation of the tunnel, ensure the smooth operation of trains and other transportation vehicles in the tunnel, and reduce safety hazards and operational risks caused by uplift or uneven settlement.

[0041] By correcting the upward or uneven settlement of all the tunnel segments 11, the upward or uneven settlement of the shield tunnel 1 is corrected, thereby improving the vertical stability of the entire shield tunnel 1. After correction, the tunnel experiences more uniform and reasonable vertical stress, reducing the accumulation of vertical deformation caused by local stress concentration or insufficient soil bearing capacity. This enhances the tunnel's ability to resist the influence of external loads and environmental changes, such as reducing the impact of groundwater level changes and surrounding construction projects on the tunnel's vertical stability, improving the tunnel's safety and reliability, and extending the service life of the shield tunnel 1.

[0042] The formation of vertical piles also serves as a reinforcement and improvement process for the surrounding soil. Grouting material fills the soil pores, creating a more integrated composite foundation between the soil and the piles, thus enhancing the soil's vertical bearing capacity and resistance to deformation. This not only provides more reliable vertical support for segment 11 but also improves the interaction between the tunnel and the soil, enabling the tunnel to better adapt to changes in the soil environment during operation and reducing secondary deformation caused by factors such as soil settlement or uplift in the later stages.

[0043] The construction method for forming inclined piles is as follows: 1.1.1.1) High-pressure jet grouting is used to inject grout into the soil layer outside the individual segment 11 of the shield tunnel 1 to form a pile column that is relatively inclined to the vertical plane on the outer circular surface of the segment 11. The grouting pressure during the grouting process acts on the segment 11 through the soil layer outside the segment 11, thereby generating a supporting force on the segment 11 to provide oblique support, thus achieving oblique support for the individual segment 11.

[0044] 2.1.1.1) Repeat step 1.1.1.1) until all the set oblique supports of the tunnel segments 11 are completed. In this way, the oblique support of the shield tunnel 1 is completed.

[0045] By grouting, piles inclined relative to the vertical plane are formed on the outside of segment 11, providing oblique support force for segment 11, thereby achieving oblique support for the shield tunnel. This oblique support can effectively resist the oblique deformation that segment 11 may undergo under complex stress environments, enhance the stability of segment 11 in all directions of space, make up for the shortcomings of simple horizontal and vertical correction, make the stress system of segment 11 more complete, improve the overall stability and bearing capacity of the tunnel structure, and better adapt to the requirements of different geological conditions and construction environments for the tunnel structure.

[0046] Multiple inclined piles, along with horizontal and vertical piles, work together to form a spatial pile group structure, greatly enhancing the overall rigidity of shield tunnel 1. When the tunnel is subjected to external loads, such as the impact force generated by passing trains or pressure changes in the surrounding soil, this rigid frame structure can more effectively disperse and transmit stress, reduce local stress concentration, lower the risk of cracking and deformation of segment 11, ensure the structural safety and stability of the tunnel during long-term operation, and reduce the amount of maintenance and repair work caused by insufficient structural rigidity.

[0047] By controlling the grouting pressure and sequence during pile construction, the aim is to correct tunnels with excessive deformation. The construction sequence is: horizontal piles 2 → vertical piles 3 → inclined piles 4, that is, first construct all horizontal piles 2, then construct all vertical piles 3, and finally construct all inclined piles 4.

[0048] Based on the deformation correction practice of a tunnel section of Harbin Line 1, this method can achieve a settlement correction range of 15% to 45% and a lateral convergence deformation correction range of 5% to 40% for shield tunnel 1.

[0049] Furthermore, in step 1), before grouting using the high-pressure jet grouting method, the service status of the shield tunnel is first determined based on the monitored segment deformation data. Then, the correction target for the segment 11 with excessive deformation is set according to the service status of the shield tunnel. Finally, the design scheme and construction procedure of the pile group are determined. The pile group is a spatial combination of piles on the outer circular surface of the shield tunnel.

[0050] Preferably, in step 1), the method for controlling the grouting pressure is as follows: 1a) After grouting the soil layer for a set time using the set grouting pressure and return pressure, measure the displacement of the side wall of segment 11; 1b) Compare the measured value of the sidewall displacement of segment 11 with the target value of the sidewall displacement of segment 11. If the measured value is less than the target value, increase the set grouting pressure and / or decrease the return grouting pressure, and then return to step 1a; if it is not less than the target value, continue grouting according to the grouting pressure set in step 1a.

[0051] Grout return is the process of releasing grout out of the borehole to regulate the pressure within the soil layer. In high-pressure grouting, the grout return pressure is controlled by a pressure balancing tank, which has a pressure gauge for reading. During grouting, the cement grout exerts pressure on the soil layer, and the soil layer also exerts a reaction force on the tunnel lining segments. Grout return controls the force exerted by the cement grout on the tunnel lining segments, preventing excessive pressure within the soil layer that could cause soil disturbance or worsen segment deformation, thus achieving precise correction.

[0052] By dynamically adjusting the grouting pressure and / or return grouting pressure, precise control of the straightening pressure can be achieved. This ensures that the pressure on the segment 11 during the straightening process matches its deformation degree and the required straightening amount, avoiding damage to the segment 11 due to excessive grouting pressure or poor straightening effect due to insufficient pressure. This improves the accuracy and reliability of the straightening, ensuring that the final straightening effect meets the design and construction requirements.

[0053] This grouting pressure control method uses feedback adjustments based on actual measurement data. It can promptly detect and correct deviations in grouting pressure during construction, ensuring the continuity and stability of grouting construction. It avoids problems such as construction interruption or rework caused by excessive pressure fluctuations, improves construction efficiency, shortens the construction period, and reduces construction costs. It also reduces the impact of excessively long construction periods on the normal operation of the tunnel and the surrounding environment.

[0054] Furthermore, regarding the tunnel deformation correction mechanism under grouting, factors such as strata and grouting parameters should be comprehensively considered first to study the relationship between grouting pressure and the load transmitted to the tunnel segments. Then, using the principle of minimum potential energy, a model of the strain energy of tunnel structural deformation and the external force work caused by grouting should be established. The strain energy is divided into rigid deformation caused by the rotation of the segment joints and flexible deformation caused by segment deflection. The external force work consists of the work done by the grouting pressure acting directly on the segments and the compaction effect of the composite strata (after grouting). Finally, the single load-structure model or strata-structure model in traditional calculation theory should be combined and unified.

[0055] Based on the above tunnel deformation correction mechanism, a simplified calculation is performed for the segment deformation correction of shield tunnels.

[0056] Furthermore, in step 2), only one pile is grouted at a time to form a single pile column. Grouting is performed sequentially according to the construction sequence to form a batch of vertical pile columns, and the first pile column is then... i The second grouting is used to correct floating or uneven settlement of the segments. i Vertical displacement of a single tunnel segment δ i The calculation method is as follows: δ i = δ ii + δji ; in, δ i For the first i The total vertical correction amount for each segment, in meters; δ ii For the first i The vertical correction amount of each segment during grouting is expressed in meters (m). δ ji For the first j When grouting the first segment, the first i Vertical correction amount for each segment, in meters. j The first segment and the first i Each segment is a different segment, and: ; c i For the first i The other pipe segments next to the first pipe segment are related to the first... i The constraint influence coefficient of each tunnel segment needs to be determined through field tests or experience. Δ P i For the first i The correction pressure on each segment is expressed in MPa, and Δ P i = P i × β , P i For the first i Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; A 1i To correct the pressure acting on the first i The effective working area per meter of the reinforced body of each segment, in m², wherein the reinforced body is the end of the pile that contacts the segment and is the thickened end; K vi For the first i The soil reaction coefficient next to each segment, in kN / m³, needs to be determined by on-site testing or experience. e i For the first i The compaction coefficient between each pipe segment and the soil needs to be determined through on-site testing or experience. A 2iThe effective working area of ​​the soil on the side of the shield tunnel opposite to the pile is measured in m². ; δ jj For the first j The vertical correction amount of each segment grouting itself, in meters; d ji = L ji + L 0 ,in L ji For the first j The first segment and the first i The distance between each segment L 0 The axial length of a single segment. d ji , L ji and L 0 The unit is m, the first j The first segment and the first i Each segment is a different segment; k This is the attenuation factor, with a value ranging from 1 to 2; n Other factors may affect the first step during grouting. i The total number of segments whose vertical correction is required; c j For the first j The other pipe segments next to the first pipe segment are related to the first... j The constraint influence coefficient of each tunnel segment needs to be determined through field tests or experience. Δ P j For the first j The correction pressure on each segment is expressed in MPa, and Δ P j = P j × β , P j For the first j Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; A 1j To correct the pressure acting on the first jThe effective working area per meter of the reinforced body of each segment, in m², wherein the reinforced body is the end of the pile that contacts the segment and is the thickened end; K vj For the first j The soil reaction coefficient next to each segment, in kN / m³, needs to be determined by on-site testing or experience. e j For the first j The compaction coefficient between each pipe segment and the soil needs to be determined through on-site testing or experience. A 2j It represents the effective working area of ​​the soil per meter on the side of the shield tunnel opposite to the pile, expressed in m².

[0057] Furthermore, in step 2), each grouting session forms only one pile column, and grouting is performed sequentially according to the construction sequence to form a batch of horizontal pile columns, and the first... i The segment for which lateral convergence correction was performed during the second grouting was the first... i For the first segment, lateral convergence is the deformation in the horizontal direction; therefore, the lateral convergence correction amount is the horizontal correction amount. Then, the first segment... i Total correction amount of lateral convergence for each segment S i The calculation method is as follows: S i = S ii + S ji ; S ii For the first i The lateral convergence correction amount of each segment during grouting is expressed in meters. S ji For the first j When grouting the first segment, the first i The lateral convergence correction amount for each segment, in meters, is... j The first segment and the first i Each segment is a different segment; ; Δ P i For the first i The correction pressure on each segment is expressed in MPa, and Δ P i = P i × β , P i For the firsti Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; e i For the first i The compaction coefficient between each pipe segment and the soil needs to be determined through on-site testing or experience. R i = r i + t / 2, in meters, and r i For the first i The inner diameter of each segment, t For the first i The horizontal thickness of each segment; v ci For the first i Poisson's ratio of concrete for each tunnel segment; E ci For the first i The elastic modulus of concrete for each segment, in MPa; b i For the first i The thickness of each segment in the horizontal direction is expressed in meters (m). f i For the first i Stiffness reduction factor for each tunnel segment; ; S jj For the first j The lateral convergence correction amount of each segment grouting is expressed in meters. d ji = L ji + L 0 ,in L ji For the first j The first segment and the first i The distance between each segment L 0 The axial length of a single segment. d ji , L ji and L 0 The unit is m, the first j The first segment and the first iEach segment is a different segment; Δ P j For the first j The correction pressure on each segment is expressed in MPa, and Δ P j = P j × β , P j For the first j Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; e j For the first j The compaction coefficient between each pipe segment and the soil needs to be determined through on-site testing or experience. R j For the first j The horizontal inner diameter of each segment, in meters; v cj For the first j Poisson's ratio of concrete for each tunnel segment; E cj For the first j The elastic modulus of concrete for each segment, in MPa; b j For the first j The thickness of each segment in the horizontal direction is expressed in meters (m). f j For the first j Stiffness reduction factor for each tunnel segment; k This is the attenuation factor, with a value ranging from 1 to 2; N Other factors may affect the first step during grouting. i The total number of segments requiring horizontal correction.

[0058] Furthermore, refer to Figure 10 If the TJS method is used to construct the piles, the specific process is as follows: b1. Layout: Based on the design drawings and the actual site conditions, determine the axis of the original grouting holes of segment 11 and the location of the new holes that need to be opened on segment 11. It is preferable to use paint and steel nails to mark the location of the piles. If the existing lining grouting holes or hoisting holes are used, no holes need to be opened.

[0059] b2. If the existing grouting holes on segment 11 are used directly for grouting, proceed to step S3. If a new grouting hole is to be drilled on segment 11, the specific steps are as follows: After drilling to the inner wall of the protective layer of segment 11, pull back the drill bit, then insert a casing into the hole of segment 11, and inject epoxy resin or adhesive between the casing and the hole wall of the newly drilled hole (two working conditions are handled when inserting the casing: the first working condition is that the track bed is found to be void after the new hole is drilled, and epoxy resin is injected between the casing wall and the new hole wall; the second working condition is that the track bed is not void after the new hole is drilled, and adhesive is injected). Then, the sealing and anti-blowing device is installed on the rear casing to prevent soil and sand from flowing out during the drilling process and cement slurry from flowing out during the construction process. Finally, a manual water drill is used to drill from the sealing and anti-blowing device at the hole opening and penetrate the protective layer of segment 11 until the drill bit of the manual water drill contacts the original soil outside segment 11, and then the manual water drill used for drilling is pulled back.

[0060] If the pile is a vertical pile 3, then the opening of the vertical pile 3 is in the middle of the track bed.

[0061] During the drilling process, when drilling reaches the outer edge of the segment where only the protective layer remains, stop drilling and promptly install a sealing and anti-spraying device.

[0062] The sealing and anti-spraying device includes components such as a gate valve and a sealing device. If the existing lifting hole or grouting hole of the pipe ring is used, the end of the gate valve is connected to the thread of the existing lifting hole or grouting hole by threading. If a new hole is drilled, the sleeve is fixed to the pipe ring after installation, and then the gate valve is installed on the threaded hole base.

[0063] The newly drilled casing is sealed to the tunnel wall via a gasket. A gate valve is threaded to the end of the casing, and the gate valve is bolted to the sealing device. A gasket is also installed between the bolted connection between the gate valve and the sealing device to prevent soil and sand from flowing out during drilling and cement slurry from flowing out during construction.

[0064] b3. Main unit installation and positioning: According to the axis and hole position determined in step S1, move the main unit of the operating platform into position, connect the data cable, adjust the position and direction of the main unit, so that the center of the drill bit of the main unit is aligned with the axis or hole position, and ensure that the deviation between the center of the drill bit and the pile position is within the set range, preferably no more than 10mm, and then fix the operating platform firmly.

[0065] b4. Pre-hole drilling: High-pressure water is used for pre-hole drilling. During the pre-hole drilling process, a robotic rod-joining device is used to join the drill rods. After each drill rod is advanced, the high-pressure water is temporarily shut off, and the robotic rod-joining device performs the joining operation for the next drill rod. During the joining process, carefully check whether the sealing rings are missing or damaged, and whether the ground pressure display is normal.

[0066] During the construction of vertical pilot holes, in order to prevent the borehole wall from collapsing and burying the drill bit, especially when drilling in sandy silt strata, bentonite mud should be used for wall protection drilling. The viscosity of the bentonite mud should not be less than 19s.

[0067] b5. Prepare cement slurry: Mix cement slurry according to the set water-cement ratio, and after the cement slurry is filtered, it is continuously pumped to the operating platform by a high-pressure pump for spraying operation.

[0068] Specifically, 20 minutes after the pilot hole reaches the design elevation, the cement slurry is prepared. An automatic mixing mode is used, with mixing parameters set and the cement slurry mixed according to the set water-cement ratio. During slurry preparation, the upper mixing tank is equipped with an automatic batching system. After uniform mixing, the discharge switch is turned on, and the cement slurry is discharged through a filter screen to the lower mixing tank. The lower mixing system is then turned on for secondary mixing of the cement slurry in the lower storage tank. After filtration, the slurry is continuously pumped by a high-pressure pump to the front-end for spraying operations.

[0069] b6. Jetting grouting: First, a circumferential cushion layer is constructed on the outer wall of segment 11, and then the pile column is constructed. The grouting pressure during the construction of the pile column generates a corrective pressure on segment 11 to correct the deformation of segment 11. The grouting parameters are shown in Table 1.

[0070] Table 1 Grouting Parameters

[0071] Specifically, after the drill bit reaches the predetermined depth, the various process parameters are set. Once all data is normal, the water is immediately switched to cement slurry, and the drill rod is pushed back into place before the grouting process begins.

[0072] During the jet grouting process, waste grout also needs to be recycled. Usable waste grout is added to cement grout for jet grouting, while unusable waste grout is disposed of as waste material after the grout has solidified and is taken off the equipment.

[0073] b7. Digital tracking grouting: First, the pile columns are constructed, and then the gap between the pile columns and the segment 11 is tracked and grouting is used to fill the gap in order to control the deformation of the shield tunnel 1.

[0074] Specifically, the radial cement-soil pile reinforcement technology for shield tunnels is divided into two stages. The first stage is the process of forming radial cement-soil piles; the second stage is the process of digital tracking grouting. Because there will be gaps between the top of the cement-soil pile and the tunnel lining segments, grouting should be carried out on these gaps in a timely manner to control tunnel deformation. The secondary grouting uses a two-liquid grout.

[0075] b8. Sealing and curing: Close the gate valve of the sealing blowout preventer. After the grout has completely solidified, open the gate valve to check for any mud or sand leakage. If there is no leakage, remove the sealing blowout preventer and then seal the grouting holes on segment 11. If there is leakage, reopen the gate valve of the sealing blowout preventer and re-grout the leaking area until the grout has completely solidified and there is no mud or sand leakage after another check. Then remove the sealing blowout preventer and seal the grouting holes on segment 11.

[0076] For the grouting holes of existing segments, a grouting hole sealing method can be adopted: a grouting hole pre-embedded part is provided on the segment 11, the grouting hole pre-embedded part surrounds the grouting hole, cement grout is injected into the grouting hole to fill it tightly, and after the cement grout solidifies, a plug is installed at the end of the grouting hole pre-embedded part near the inner arc surface of the segment, and the plug is threadedly connected to the grouting hole pre-embedded part.

[0077] For newly opened grouting holes, after removing the gate valve, the inside of the casing is filled with C30 sulfoaluminate micro-expansion cement, and the end of the casing is sealed with a spiral plug. Water-stop tape is wrapped around the spiral plug to prevent leakage.

[0078] According to another aspect of the present invention, a pile column for correcting convergence deformation of a shield tunnel is also provided, which is formed after the shield tunnel 1 is corrected using the correction method described above.

[0079] The piles formed by the above-mentioned correction method are not only a direct result of the deformation correction of segment 11, but also form a composite structure with good mechanical properties and stability with the surrounding soil. These piles can provide long-term stable support and restraint for segment 11, effectively resisting various internal and external loads on the tunnel during operation, preventing segment 11 from deforming again, ensuring the geometric and structural stability of the tunnel, and providing a reliable guarantee for the safe operation of urban rail transit.

[0080] Furthermore, for the cases where the constructed piles are vertical piles 3 and inclined piles 4, enlarged ends 6 are provided on both vertical piles 3 and inclined piles 4, and the diameter of the enlarged ends 6 is enlarged relative to other parts of the piles.

[0081] During the deformation correction process of a shield tunnel, the enlarged end 6 provides a more effective support point for the correction pressure. When the grouting pressure acts on the soil layer outside the segment 11, the enlarged end 6 can better transmit the correction pressure to the segment 11, allowing the segment 11 to displace more accurately according to the design requirements, thereby achieving more precise deformation correction. For example, when correcting the horizontal deformation of the segment, the enlarged end 6 on the horizontal pile can more firmly abut against the soil, allowing the grouting pressure to be more effectively converted into lateral thrust on the segment, prompting the segment to return to the correct horizontal position.

[0082] After correction, the presence of the enlarged end 6 helps maintain the corrected state. It acts like a stable "anchor point," preventing the segments from deforming again during subsequent use due to uneven soil settlement, train vibration, or other factors. This ensures the long-term effectiveness of the correction, reduces the likelihood of needing secondary correction due to repeated deformation, and lowers maintenance costs and construction risks.

[0083] The enlarged area of ​​the enlarged end 6 can better distribute the force borne by the pile to the surrounding soil. This avoids excessive stress concentration in the soil due to excessively thin piles, which could lead to localized soil damage or deformation. This stress dispersion helps improve the stress state of the soil, enhances its overall stability, and allows the soil around the shield tunnel to bear external loads more evenly, reducing the adverse effects of the soil on the tunnel and creating favorable geological conditions for the long-term safe operation of the tunnel.

[0084] The presence of enlarged end 6 makes the bond between the pile and the soil tighter, forming a more organic whole. When the tunnel is subjected to external loads, the pile can more effectively drive the surrounding soil to resist deformation, giving full play to the advantages of the synergistic effect between the pile and the soil. This synergistic effect not only improves the overall bearing capacity of the tunnel, but also reduces the relative displacement between the soil and the pile, reducing the potential risks caused by the separation or sliding between the two, and further enhancing the reliability and durability of the tunnel structure.

[0085] Because the enlarged end 6 increases the contact area and friction between the pile and the soil, the pile is better embedded in the soil. After construction, it can effectively reduce the risk of pile tilting or breakage caused by uneven soil settlement, ensuring the quality and service life of the pile, while also ensuring the structural quality of the shield tunnel, avoiding tunnel deformation or other structural defects caused by pile problems, and extending the service life of the tunnel.

[0086] In the long term, the design of enlarged end 6 helps reduce tunnel maintenance costs. By enhancing the support capacity and durability of the piles, it reduces the repair and replacement work required due to pile failure or deformation.

[0087] According to another aspect of the present invention, a shield tunnel over-deformation correction pile group is also provided, comprising multiple pile columns, which are formed after the shield tunnel is corrected using the correction method described above.

[0088] As a preferred embodiment, the pile group includes multiple sets of first pile groups, wherein: Each first pile group includes multiple piles, which are divided into horizontal piles 2 and vertical piles 3, and the center lines of the horizontal piles 2 and the vertical piles 3 intersect with the center line of the segment 11. The first pile group in each group consists of two horizontal piles 2 and one vertical pile 3; The centerlines of the two horizontal piles 2 and one vertical pile 3 in the first pile group of each group are coplanar; The two horizontal piles 2 of the first pile group in each group are symmetrically arranged on the segment 11. The two horizontal piles 2 and one vertical pile 3 of the first pile group in each group are installed on the same segment 11 of the shield tunnel 1. Any two adjacent groups of first pile columns are arranged with at least one segment 11 between them.

[0089] The layout design of the first pile group allows each pile group to effectively constrain and correct the horizontal and vertical deformation of the tunnel segment 11, while ensuring a reasonable force transmission path and balanced stress distribution. Adjacent pile groups are spaced at least one tunnel segment 11 apart, avoiding stress interference and excessive soil disturbance caused by overly dense piles. This ensures that each pile group can function independently, while simultaneously forming an organic whole where the entire pile group collectively undertakes the task of correcting and reinforcing the tunnel, improving the correction effect and structural stability.

[0090] The construction method for the pile group formed by the first pile column group includes the following steps: c1) First, construct all the horizontal piles 2. During the construction of the horizontal piles 2, except for the first horizontal pile 2, the construction of the other horizontal piles 2 shall be carried out in the following manner: the horizontal piles 2 constructed this time shall be spaced 4 to 5 segments 11 apart from the horizontal piles 2 constructed last time, and the projections of the horizontal piles 2 constructed this time and the horizontal piles 2 constructed last time on the cross section of the segment 11 shall be symmetrical.

[0091] c2) Construct all vertical piles 3, and during the construction of vertical piles 3, except for the first vertical pile 3 constructed, the construction of other vertical piles 3 shall be carried out in the following manner: the vertical pile 3 being constructed this time shall be spaced 4-5 segments 11 apart from the vertical pile 3 constructed previously. See [link / reference] Figure 4 Z1~Z5 represent the construction sequence of vertical piles 3, with Z1 being the first vertical pile 3 to be constructed, Z2 being the second vertical pile 3 to be constructed, and so on; S1~S10 represent the construction sequence of horizontal piles 2, with S1 being the first horizontal pile 2 to be constructed, S2 being the second horizontal pile 2 to be constructed, and so on.

[0092] In this construction method, all horizontal piles 2 are constructed first, followed by vertical piles 3. The construction intervals and projection symmetry requirements for subsequent horizontal piles 2 and vertical piles 3, except for the initial construction, are specified. This orderly construction sequence facilitates the rational arrangement of the construction schedule, fully utilizes the preliminary reinforcement effect of the piles formed in the earlier construction phases, and provides a more stable environment for subsequent construction. Simultaneously, the interval and symmetrical construction requirements avoid stress concentration and uneven soil deformation during construction, reducing additional tunnel deformation caused by construction and its impact on the surrounding environment, thus lowering construction risks.

[0093] As a preferred embodiment, the pile group includes multiple sets of second pile groups, wherein: Each group of the second pile column includes multiple pile columns, which include horizontal piles 2 and vertical piles 3, and the center lines of the horizontal piles 2 and vertical piles 3 intersect the center line of the segment 11.

[0094] The second pile group in each set consists of two horizontal piles 2 and one vertical pile 3.

[0095] Each second pile group also includes two inclined piles 4 and a vertical pile 3 located between the two inclined piles 4.

[0096] The two inclined piles 4 of the second pile group in each group are arranged symmetrically on the pipe segment 11.

[0097] The centerlines of the two inclined piles 4, one vertical pile 3, and two horizontal piles 2 in the second pile group of each group are coplanar.

[0098] The two horizontal piles 2 of the second pile group are arranged symmetrically. The two inclined piles 4, one vertical pile 3 and two horizontal piles 2 of each second pile group are installed on the same segment 11 of the shield tunnel 1. Any two adjacent second pile groups are arranged with at least one segment 11 between them.

[0099] This design of the second pile group not only provides horizontal and vertical correction capabilities for each pile group, but also increases diagonal support, enabling it to more comprehensively resist the deformation of the tunnel segment 11 in all spatial directions and improving the support stiffness and stability of the pile group for the tunnel segment 11. The synergistic effect of the inclined piles 4, vertical piles 3, and horizontal piles 2 forms a three-dimensional spatial support system, enhancing the overall bearing capacity and deformation resistance of the pile group, and better adapting to the changing needs of complex geological conditions and tunnel stress environment.

[0100] The construction method for the pile group formed by the second pile column group includes the following steps: d1) First, construct all the horizontal piles 2. During the construction of the horizontal piles 2, except for the first horizontal pile 2, the construction of the other horizontal piles 2 shall be carried out in the following manner: the horizontal piles 2 constructed this time shall be spaced 4 to 5 segments 11 apart from the horizontal piles 2 constructed last time, and the projections of the horizontal piles 2 constructed this time and the horizontal piles 2 constructed last time on the cross section of the segment 11 shall be symmetrical.

[0101] d2) Construct all the vertical piles 3 again, and during the construction of the vertical piles 3, except for the first vertical piles 3, the construction of the other vertical piles 3 shall be carried out in the following manner: the vertical piles 3 constructed this time shall be spaced 4 to 5 segments 11 apart from the vertical piles 3 constructed last time.

[0102] d3) Finally, construct all the inclined piles 4. During the construction of the inclined piles 4, except for the inclined piles 4 constructed in the first construction, the construction of the other inclined piles 4 shall be carried out in the following manner: the inclined piles 4 constructed this time shall be spaced 4-5 segments 11 apart from the inclined piles 4 constructed previously, and the projections of the inclined piles 4 constructed this time and the inclined piles 4 constructed previously on the cross-section of the segment 11 shall be symmetrical. See Figure 6 Z1~Z3 represent the construction sequence of vertical piles 3, with Z1 being the first vertical pile 3 to be constructed, Z2 being the second vertical pile 3 to be constructed, and so on; S1~S6 represent the construction sequence of horizontal piles 2, with S1 being the first horizontal pile 2 to be constructed, S2 being the second horizontal pile 2 to be constructed, and so on; X1~X6 represent the construction sequence of inclined piles 4, with X1 being the first inclined pile 4 to be constructed, X2 being the second inclined pile 4 to be constructed, and so on.

[0103] This invention constructs horizontal piles 2 first, then vertical piles 3, and finally inclined piles 4, specifying the subsequent construction intervals and symmetry requirements for each type of pile. This construction organization arrangement facilitates the rational allocation of construction resources, avoids mutual interference during the construction of different piles, and ensures the construction quality and efficiency of each type of pile. Simultaneously, through symmetrical construction and interval arrangement, the stress generated during construction can be gradually balanced and released, reducing tunnel deformation and soil disturbance caused by improper construction sequence, thus ensuring the smooth progress of construction and the safety and stability of the tunnel structure.

[0104] As another preferred embodiment, the pile group includes multiple sets of third pile groups, wherein: Each of the third pile groups includes multiple piles, including horizontal piles 2 and vertical piles 3, and the centerlines of the horizontal piles 2 and vertical piles 3 intersect the centerline of the segment 11.

[0105] Each group of the third pile group consists of one horizontal pile 2 and one vertical pile 3.

[0106] Each group of the third pile group also includes an inclined pile 4, and there is an angle between the inclined pile 4 and the vertical pile 3.

[0107] The centerlines of the inclined pile 4, the vertical pile 3, and the horizontal pile 2 in the third pile group of each group are coplanar.

[0108] One inclined pile 4, one vertical pile 3, and one horizontal pile 2 of the third pile group in each group are installed on the same segment 11.

[0109] For any two adjacent groups of third piles, the projections of the two inclined piles 4 on the cross section of the segment 11 are symmetrical, the projections of the two horizontal piles 2 on the cross section of the segment 11 are also symmetrical, and the center lines of the vertical piles 3 all intersect with the center line of the segment 11.

[0110] Each third pile group consists of one horizontal pile 2, one vertical pile 3, and one inclined pile 4. The structure is relatively simple, but the functions are complete. Reducing the number of each type of pile makes the pile group layout more compact, minimizing the space occupied in the tunnel and the extent of soil disturbance. Simultaneously, each pile group is installed on the same segment 11 of the shield tunnel 1, facilitating construction positioning and operation, improving construction efficiency and accuracy, and reducing construction costs and difficulty. This is particularly suitable for the correction of shield tunnel 1 in areas with limited space or complex geological conditions.

[0111] The projections of the inclined piles 4 and horizontal piles 2 of the two adjacent third pile groups on the cross-section of segment 11 are symmetrical, and the centerlines of the vertical piles 3 all intersect the centerline of segment 11. This symmetrical design ensures a uniform distribution of forces around segment 11, avoiding problems such as local stress concentration and tunnel displacement caused by asymmetrical pile arrangement, and improving the stability and correction effect of the entire pile group. The symmetrical structure also helps the pile group better adapt to dynamic deformation and vibration caused by train loads during operation, enhancing the reliability and durability of the tunnel structure.

[0112] The construction method for the pile group formed by the third pile group includes the following steps: e1) First, construct all the horizontal piles 2. During the construction of the horizontal piles 2, except for the first horizontal pile 2, the construction of the other horizontal piles 2 shall be carried out in the following manner: the horizontal piles 2 constructed this time shall be spaced 4 to 5 segments 11 apart from the horizontal piles 2 constructed last time, and the projections of the horizontal piles 2 constructed this time and the horizontal piles 2 constructed last time on the cross section of the segment 11 shall be symmetrical.

[0113] e2) Construct all the vertical piles 3 again, and during the construction of the vertical piles 3, except for the first vertical piles 3, the construction of the other vertical piles 3 shall be carried out in the following manner: the vertical piles 3 constructed this time shall be spaced 4 to 5 segments 11 apart from the vertical piles 3 constructed last time.

[0114] e3) Finally, construct all the inclined piles 4. During the construction of the inclined piles 4, except for the inclined piles 4 constructed in the first stage, the construction of the other inclined piles 4 shall be carried out in the following manner: the inclined piles 4 constructed this time shall be spaced 4 to 5 segments 11 apart from the inclined piles 4 constructed previously, and the projections of the inclined piles 4 constructed this time and the inclined piles 4 constructed previously on the cross-section of the segment 11 shall be symmetrical. See Figure 8 Z1~Z5 represent the construction sequence of vertical piles 3, with Z1 being the first vertical pile 3 to be constructed, Z2 being the second vertical pile 3 to be constructed, and so on; S1~S9 represent the construction sequence of horizontal piles 2, with S1 being the first horizontal pile 2 to be constructed, S2 being the second horizontal pile 2 to be constructed, and so on; X1~X9 represent the construction sequence of inclined piles 4, with X1 being the first inclined pile 4 to be constructed, X2 being the second inclined pile 4 to be constructed, and so on.

[0115] The construction method for the pile group formed by the third pile group requires that the projections of the horizontal piles 2 and inclined piles 4 constructed in this phase be symmetrical with those of the same type constructed in the previous phase on the cross-section of segment 11. This helps ensure a uniform distribution of stress around segment 11, avoiding problems such as local stress concentration and tunnel displacement caused by asymmetrical pile arrangement, and improving the stability and correction effect of the entire pile group. By adopting a reasonable construction sequence and interval requirements, excessively concentrated pile construction in the same area is avoided, thereby reducing disturbance to the shield tunnel 1 and the surrounding soil, which is conducive to maintaining the original structure and stability of the soil and reducing the impact of construction on the surrounding environment.

[0116] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for correcting excessive deformation in shield tunnels, characterized in that, Includes the following steps: 1) High-pressure jet grouting is used to inject grout into the soil layer outside the individual segment with excessive deformation to form a pile column on the outer circumference of the segment. The grouting pressure during the grouting process acts on the segment through the soil layer outside the segment, thereby generating a corrective pressure on the segment to correct the excessive deformation of the segment, thus achieving the correction of the excessive deformation of the individual segment; wherein, the center line of the formed pile column intersects with the center line of the segment, and the corrective pressure acting on the segment is adjusted by adjusting the grouting pressure and / or the return grouting pressure; 2) Repeat step 1) until all segments of the shield tunnel that have exceeded the deformation limit have been corrected. In this way, the excessive deformation of the shield tunnel can be corrected.

2. The method for correcting excessive deformation in shield tunnels according to claim 1, characterized in that, Step 2) Among the multiple piles formed, there are horizontal piles. During the process of forming horizontal piles through grouting, a corrective pressure is generated on the tunnel segment to correct the lateral convergence deformation of the tunnel segment, thereby correcting the excessive lateral convergence deformation of the shield tunnel. and / or; Step 2) involves the formation of multiple piles, including vertical piles. During the grouting process to form these vertical piles, corrective pressure is generated on the tunnel segments to correct any upward movement or uneven settlement of the segments, thereby correcting any upward movement or uneven settlement of the shield tunnel. Specifically, when correcting the upward movement of the shield tunnel, the vertical piles are located above the shield tunnel; when correcting the uneven settlement of the shield tunnel, the vertical piles are located below the shield tunnel. and / or; Step 2) Among the multiple piles formed, there are piles that are inclined relative to the vertical plane. During the process of grouting to form piles that are inclined relative to the vertical plane, a supporting force is generated on the tunnel segment to provide oblique support for the tunnel segment, thereby achieving oblique support for the shield tunnel.

3. The method for correcting excessive deformation in shield tunnels according to claim 1, characterized in that, In step 1), before grouting using the high-pressure jet grouting method, the service status of the shield tunnel is first determined based on the monitored segment deformation data. Then, the correction target for segments with excessive deformation is set according to the service status of the shield tunnel. Finally, the design scheme and construction procedure of the pile group are determined. The pile group is a spatial combination of piles on the outer circular surface of the shield tunnel.

4. The method for correcting excessive deformation in shield tunnels according to claim 1, characterized in that, In step 1), the grouting pressure is controlled as follows: 1a) After grouting the soil layer for a set time using the set grouting pressure and return pressure, measure the displacement of the sidewall of the segment; 1b) Compare the measured value of the segment sidewall displacement with the target value of the segment sidewall displacement. If the measured value is less than the target value, increase the set grouting pressure and / or decrease the return grouting pressure, and then return to step 1a. If the pressure is not less than the target value, continue grouting according to the grouting pressure set in step 1a.

5. The method for correcting excessive deformation in shield tunnels according to claim 1, characterized in that, In step 2), only one pile is grouted at a time to form a single pile column. Grouting is performed sequentially according to the construction order to form a batch of vertical pile columns, and the first pile column is then... i The second grouting is used to correct floating or uneven settlement of the segments. i Vertical displacement of a single tunnel segment δ i The calculation method is as follows: δ i = δ ii + δ ji ； in, δ i For the first i The total vertical correction amount for each segment, in meters; δ ii For the first i The vertical correction amount of each segment during grouting is expressed in meters (m). δ ji For the first j When grouting the first segment, the first i Vertical correction amount for each segment, in meters. j The first segment and the first i Each segment is a different segment, and: ； c i For the first i The other pipe segments next to the first pipe segment are related to the first... i Constraint influence coefficient of each tunnel segment; Δ P i For the first i The correction pressure on each segment is expressed in MPa, and Δ P i = P i × β , P i For the first i Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; A 1i To correct the pressure acting on the first i The effective working area per meter of the reinforced body of each segment, in m², wherein the reinforced body is the end of the pile that contacts the segment and is the thickened end; K vi For the first i The soil reaction coefficient next to each tunnel segment, in kN / m³; e i For the first i The compaction coefficient between each pipe segment and the soil; A 2i The effective working area of ​​the soil on the side of the shield tunnel opposite to the pile is measured in m². ； δ jj For the first j The vertical correction amount of each segment grouting itself, in meters; d ji = L ji + L 0 ,in L ji For the first j The first segment and the first i The distance between each segment L 0 The axial length of a single segment. d ji , L ji and L 0 The unit is m, the first j The first segment and the first i Each segment is a different segment; k This is the attenuation factor, with a value ranging from 1 to 2; n Other factors may affect the first stage during grouting. i The total number of segments whose vertical correction is required; c j For the first j The other pipe segments next to the first pipe segment are related to the first... j Constraint influence coefficient of each tunnel segment; Δ P j For the first j The correction pressure on each segment is expressed in MPa, and Δ P j = P j × β , P j For the first j Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; A 1j To correct the pressure acting on the first j The effective working area per meter of the reinforced body of each segment, in m², wherein the reinforced body is the end of the pile that contacts the segment and is the thickened end; K vj For the first j The soil reaction coefficient next to each tunnel segment, in kN / m³; e j For the first j The compaction coefficient between each pipe segment and the soil; A 2j It represents the effective working area of ​​the soil per meter on the side of the shield tunnel opposite to the pile, expressed in m².

6. The method for correcting excessive deformation in shield tunnels according to claim 1, characterized in that, In step 2), each grouting operation forms only one pile column. Grouting is performed sequentially according to the construction sequence to form a batch of horizontal pile columns, and the first... i The segment for which lateral convergence correction was performed during the second grouting was the first... i The first segment, then the second i Total correction amount of lateral convergence for each segment S i The calculation method is as follows: S i = S ii + S ji ； S ii For the first i The lateral convergence correction amount of each segment during grouting is expressed in meters. S ji For the first j When grouting the first segment, the first i The lateral convergence correction amount for each segment, in meters, is... j The first segment and the first i Each segment is a different segment; ； Δ P i For the first i The correction pressure on each segment is expressed in MPa, and Δ P i = P i × β , P i For the first i Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; e i For the first i The compaction coefficient between each pipe segment and the soil; R i = r i + t / 2, in meters, and r i For the first i The inner diameter of each segment, t For the first i The horizontal thickness of each segment; v ci For the first i Poisson's ratio of concrete for each tunnel segment; E ci For the first i The elastic modulus of concrete for each segment, in MPa; b i For the first i The thickness of each segment in the horizontal direction is expressed in meters (m). f i For the first i Stiffness reduction factor for each tunnel segment; ； S jj For the first j The lateral convergence correction amount of each segment grouting is expressed in meters. d ji = L ji + L 0 ,in L ji For the first j The first segment and the first i The distance between each segment L 0 The axial length of a single segment. d ji , L ji and L 0 The unit is m, the first j The first segment and the first i Each segment is a different segment; Δ P j For the first j The correction pressure on each segment is expressed in MPa, and Δ P j = P j × β , P j For the first j Grouting pressure during segment construction β The pressure transmission efficiency coefficient of cement slurry; e j For the first j The compaction coefficient between each pipe segment and the soil; R j For the first j The horizontal inner diameter of each segment, in meters; v cj For the first j Poisson's ratio of concrete for each tunnel segment; E cj For the first j The elastic modulus of concrete for each segment, in MPa; b j For the first j The thickness of each segment in the horizontal direction is expressed in meters (m). f j For the first j Stiffness reduction factor for each tunnel segment; k This is the attenuation factor, with a value ranging from 1 to 2; N Other factors may affect the first stage during grouting. i The total number of segments requiring horizontal correction.

7. The method for correcting excessive deformation in shield tunnels according to claim 1, characterized in that, Step 2) specifically includes the following sub-steps: 2.1) Construction shall form all horizontal piles, and during the construction of the horizontal piles, except for the first horizontal piles, the construction of other horizontal piles shall be carried out in the following manner: the horizontal piles constructed in this construction shall be spaced 4 to 5 segments apart from the horizontal piles constructed in the previous construction. 2.2) Construction shall form all vertical piles, and during the construction of the vertical piles, except for the first vertical piles, the construction of the other vertical piles shall be carried out in the following manner: the vertical piles constructed this time shall be spaced 4 to 5 segments apart from the vertical piles constructed last time.

8. The method for correcting excessive deformation in shield tunnels according to claim 7, characterized in that, Step 2) also includes the following sub-steps: 2.3) Construct all inclined piles, and during the construction of inclined piles, except for the inclined piles constructed in the first construction, the construction of other inclined piles shall be carried out in the following manner: the inclined piles constructed in this construction shall be spaced 4 to 5 segments apart from the inclined piles constructed in the previous construction.

9. A pile group for correcting excessive deformation in shield tunnels, characterized in that, It includes multiple piles, and these piles are formed after the shield tunnel is corrected using the correction method described in any one of claims 1 to 8.

10. The shield tunnel deformation over-limit correction pile group according to claim 9, characterized in that, The pile group includes multiple sets of first pile groups, wherein: Each first pile group includes horizontal piles and vertical piles, with the horizontal piles and vertical piles being horizontal piles and vertical piles, respectively. The first pile group in each group consists of two horizontal piles and one vertical pile, and the centerlines of the two horizontal piles and the one vertical pile are coplanar; The two horizontal piles of the first pile group in each group are symmetrically arranged on the segment, and the two horizontal piles and one vertical pile of the first pile group in each group are installed on the same segment of the shield tunnel. Any two adjacent groups of first pile columns are spaced apart by at least one segment.

11. The shield tunnel deformation over-limit correction pile group according to claim 9, characterized in that, The pile group includes multiple sets of second pile columns, wherein: Each second pile group includes horizontal piles and vertical piles, with the horizontal piles and vertical piles being horizontal piles and vertical piles, respectively. The second pile group in each group consists of two horizontal piles and one vertical pile; Each second pile group also includes two inclined piles and a vertical pile located between the two inclined piles; The two inclined piles of the second pile group in each group are arranged symmetrically on the segments; The centerlines of the two inclined piles, one vertical pile, and two horizontal piles in the second pile group of each group are coplanar; The two horizontal piles of the second pile group are arranged symmetrically. The two inclined piles, one vertical pile and two horizontal piles of each second pile group are installed on the same segment of the shield tunnel. Any two adjacent second pile groups are arranged with at least one segment between them.

12. The shield tunnel deformation over-limit correction pile group according to claim 9, characterized in that, The pile group includes multiple sets of third pile groups, wherein: Each group of the third pile column includes horizontal pile columns and vertical pile columns, which are horizontal piles and vertical pile columns respectively. Each group of the third pile group consists of one horizontal pile and one vertical pile; Each group of the third pile column also includes a pile column whose center line is inclined relative to the vertical plane. The pile column whose center line is inclined relative to the vertical plane is an inclined pile, and there is one inclined pile. The centerlines of one inclined pile, one vertical pile, and one horizontal pile in the third pile group of each group are coplanar; One horizontal pile, one vertical pile, and one inclined pile of the third pile group in each group are installed on the same segment; For any two adjacent sets of third pile groups, the projections of the two inclined piles on the cross-section of the pipe segment are symmetrical, and the projections of the two horizontal piles on the cross-section of the pipe segment are also symmetrical.

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