Shield tunnel deformation out-of-limit correction pile group and correction method

Abstract

The present application belongs to the technical field of shield tunnel construction, and discloses a shield tunnel deformation overrun correction pile group and a correction method. The correction method comprises the following steps: 1) using a high-pressure jet grouting method to inject grout into the soil layer outside a single pipe segment of the deformation overrun shield tunnel to form a pile column on the outer circumferential surface of the pipe segment. The grouting pressure in the grouting process acts on the pipe segment through the soil layer outside the pipe segment, thereby generating a correction pressure for correcting the deformation of the deformation overrun pipe segment. The correction pressure acting on the pipe segment is adjusted by adjusting the grouting pressure and / or the back pressure. 2) repeating step 1) until the correction of all deformation overrun pipe segments of the shield tunnel is completed. The present application forms a radial pile column outside the tunnel by using a high-pressure jet grouting process, improves the soil properties around the tunnel, and controls the size of the correction force by controlling the back pressure in the jet grouting process, thereby achieving accurate correction of the deformation overrun shield tunnel and effectively ensuring the operation safety of the shield tunnel.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of shield tunnel construction, and more particularly relates to a shield tunnel deformation overrun correction pile group and a correction method. BACKGROUND

[0002] Shield tunnels face many complex environmental factors during long-term operation, leading to increasingly prominent structural deformation problems, which pose a serious threat to the safe operation of urban rail transit.

[0003] Tunnel convergence deformation refers to the uneven change in the geometric shape of a tunnel in the process of its use after construction. This deformation is usually caused by various factors, such as tunnel structure design, geological conditions, construction methods, etc.

[0004] For shield tunnel deformation, including floating, uneven settlement, and lateral convergence deformation, the floating of a shield tunnel can cause overrun, misalignment, cracking, and water leakage, and in severe cases, can lead to structural damage; uneven settlement of a shield tunnel can cause the tunnel line to bend, affecting train travel safety. Lateral convergence deformation refers to the change in the lateral dimension of a tunnel after construction. This change is usually caused by factors such as construction errors, shield tunnel assembly, etc.

[0005] The causes of shield tunnel deformation overrun are complex and varied. Peripheral soil loss and disturbance is an important factor. During shield tunnel construction, it is inevitable to cause a certain degree of damage and disturbance to the surrounding soil, leading to soil loss, making the tunnel lose its original soil support balance, and thus causing structural deformation. For example, when constructing in soft soil layers, the fluidity of the soil is greater, making it more prone to soil loss, causing the tunnel segments to bear uneven pressure and produce convergence deformation. In addition, external engineering activities also have a significant impact on the stability of shield tunnel structures. During urban underground space development, foundation construction, underground pipeline laying, road excavation, and other engineering activities are frequent, which may change the stress distribution around the shield tunnel and increase the stress complexity of the tunnel structure, thereby inducing deformation. For example, deep foundation pit excavation near the shield tunnel will cause the surrounding groundwater level to drop due to foundation pit dewatering, causing the surrounding soil of the shield tunnel to lose water and consolidate, resulting in uneven extrusion of the tunnel, causing tunnel convergence deformation. Furthermore, 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, affecting the interaction between the shield tunnel and the surrounding soil, and thus causing tunnel structural deformation.

[0006] Long-term train cyclic loading is also one of the factors that cannot be underestimated for the deformation of shield tunnels. The frequent operation of urban rail transit trains produces a continuous dynamic load on the tunnel structure. During the operation of the train, the vibration load generated by the interaction of the wheel and rail is continuously transmitted to the shield tunnel segment. After years of cumulative effects, the segment structure gradually produces fatigue damage, reduces the overall stiffness and bearing capacity of the tunnel structure, and thus promotes the deformation of the tunnel. Especially in curved tunnel sections or sections with high train running speed, the centrifugal force and impact force generated when the train passes through are greater, which can more easily exacerbate the convergence deformation of the tunnel.

[0007] In the face of the serious problem of shield tunnel deformation exceeding the limit, the existing remediation methods have many limitations. For the case of excessive settlement of shield tunnels, the common treatment method is to use the micro-disturbance double-liquid grouting method inside the tunnel. The basic principle is to inject double-liquid grout into the surrounding soil inside the tunnel to fill the voids in the soil and enhance the strength of the soil, thereby controlling the settlement. However, this micro-disturbance grouting method has obvious shortcomings. First, its improvement effect on the soil under the tunnel is very limited, and it is difficult to effectively improve the bearing capacity of the soil, resulting in poor settlement control effect. Second, the durability of the injected double-liquid grout is poor, and under the long-term action of groundwater and train load, problems such as cement grout aging and strength reduction can easily occur, making it difficult to maintain effective control of tunnel settlement in the long term. More seriously, when the grouting pressure is not properly controlled and exceeds the bearing limit of the soil, it will disturb the original stress state of the soil under the tunnel, inducing secondary settlement of the tunnel and further exacerbating the deformation of the tunnel, posing a greater hidden danger to the safety of the tunnel structure.

[0008] For the problem of excessive elliptical deformation of shield tunnels, the current common treatment method is to reinforce the tunnel with a steel ring. This method involves overlapping a layer of about 2 cm thick steel plate inside the tunnel to increase the ring stiffness of the tunnel and thus resist the elliptical deformation of the tunnel. However, through actual application and research analysis, it has been found that steel ring reinforcement has many drawbacks. On the one hand, the durability of the steel ring is poor, and under the long-term action of groundwater corrosion and train vibration load, the material properties of the steel ring will gradually deteriorate, its corrosion resistance and mechanical properties will continuously decrease, thus losing its effective reinforcement effect on the tunnel structure and posing a potential threat to the safety of the tunnel structure. On the other hand, although steel ring reinforcement can increase the ring stiffness of the tunnel to some extent, it only locally strengthens the internal structure of the tunnel and does not fundamentally solve the problem of soil imbalance that causes tunnel elliptical deformation, thus failing to completely eradicate the tunnel elliptical deformation phenomenon and leading to the possibility of tunnel deformation problems reoccurring after a period of reinforcement. SUMMARY

[0009] In view of the above defects or improvement needs of the prior art, the present application provides a shield tunnel deformation overrun correction method, a pile column, a pile group and a pile group construction method, which corrects the segment by generating a correction force on the segment during grouting construction, and the formed pile column can improve the surrounding soil, long-term solve the problem of shield tunnel deformation overrun, and the cost is lower than that of traditional micro-disturbance grouting and steel ring reinforcement.

[0010] To achieve the above object, according to one aspect of the present application, a shield tunnel deformation overrun correction method is provided, comprising the following steps:

[0011] 1) A high-pressure jet grouting method is used to grout into the soil layer outside the single segment with deformation overrun to form a pile column on the outer cylindrical surface of the segment. The grouting pressure during grouting acts on the segment through the soil layer outside the segment, thereby generating a correction pressure on the segment to correct the overrun deformation of the segment, and thereby correcting the overrun deformation of the single segment. Wherein the center line of the formed pile column intersects with the center line of the segment, and the correction pressure acting on the segment is adjusted by adjusting the grouting pressure and / or back pressure;

[0012] 2) Repeat step 1) until the correction of all segments with deformation overrun of the shield tunnel is completed. In this way, the correction of the shield tunnel deformation overrun is realized, wherein only one pile column is formed by grouting each time, a batch of vertical pile columns are formed in sequence according to the construction sequence, and the segment subjected to the floating or uneven settlement correction by the first grouting is the first segment, the vertical displacement of the single segment i i δ i is calculated as follows:

[0013] δ i = δ ii + δ ji ;

[0014] Wherein,

[0015] δ i is the total correction amount of the first i segment in the vertical direction, with unit of m;

[0016] δ ii is the vertical correction amount of the first i segment itself when grouting, with unit of m;

[0017] δ ji is the vertical correction amount of the first j segment when the first i segment grouts, with unit of m, the first​​j The first segment and the first i Each segment is a different segment, and:

[0018] ;

[0019] 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;

[0020] 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;

[0021] 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;

[0022] K vi For the first i The soil reaction coefficient next to each tunnel segment, in kN / m³;

[0023] e i For the first i The compaction coefficient between each pipe segment and the soil;

[0024] A 2i The effective working area of ​​the soil on the side of the shield tunnel opposite to the pile is measured in m².

[0025] ;

[0026] δ jj For the first j The vertical correction amount of each segment during grouting, in meters;

[0027] d ji = Lji + 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;

[0028] k This is the attenuation factor, with a value ranging from 1 to 2;

[0029] n Other factors may affect the first stage during grouting. i The total number of segments whose vertical correction is required;

[0030] 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;

[0031] 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;

[0032] 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;

[0033] K vj For the first j The soil reaction coefficient next to each tunnel segment, in kN / m³;

[0034] ej is the compactness coefficient between the j

[0035] A 2j is the effective action area per meter of the soil on the side opposite to the pile column of the shield tunnel, with the unit of m².

[0036] Preferably, among the plurality of pile columns formed in step 2), there are horizontal pile columns to generate a correction pressure on the segment to correct the lateral convergence deformation of the segment during the grouting process of forming the horizontal pile columns, so as to correct the lateral convergence deformation of the shield tunnel beyond the limit;

[0037] and / or;

[0038] Among the plurality of pile columns formed in step 2), there are vertical pile columns to generate a correction pressure on the segment to correct the floating or uneven settlement of the segment during the grouting process of forming the vertical pile columns, so as to correct the floating or uneven settlement of the shield tunnel; wherein the vertical pile columns are located above the shield tunnel when correcting the floating of the shield tunnel, and the vertical pile columns are located below the shield tunnel when correcting the uneven settlement of the shield tunnel;

[0039] and / or;

[0040] Among the plurality of pile columns formed in step 2), there are pile columns inclined relative to the vertical plane to generate a support force on the segment to support the segment obliquely during the grouting process of forming the pile columns inclined relative to the vertical plane, so as to support the shield tunnel obliquely.

[0041] Preferably, in step 1), before grouting by using the high-pressure jet grouting method, the service state of the shield tunnel is determined based on the monitored segment deformation data, the correction target of the segment beyond the limit of deformation is set according to the service state of the shield tunnel, and finally the design scheme and construction process of the pile group are determined, wherein the pile group is a spatial combination composed of pile columns on the outer cylindrical surface of the shield tunnel.

[0042] Preferably, in step 1), the control method of grouting pressure is as follows:

[0043] 1a) After grouting for a set time by using the set grouting pressure and back pressure, the displacement of the segment side wall is measured;

[0044] 1b) The measured value of the segment side wall displacement is compared with the target value of the segment side wall displacement, if the measured value is less than the target value, the set grouting pressure is increased and / or the back pressure is decreased, and then returns to step 1a; if not, continue grouting according to the set grouting pressure of step 1a.

[0045] ​Preferably, in step 2), only one pile is formed each time of grouting, and a batch of horizontal piles are formed in sequence according to the construction sequence, and the first grouting is performed to correct the lateral convergence of the first pipe segment. i The pipe segment for the first grouting to correct the lateral convergence is the first pipe segment. i The total correction amount of the lateral convergence of the first pipe segment is the lateral convergence correction amount of the first pipe segment when the first pipe segment is grouted. i S i The calculation method is as follows:

[0046] S i S ii S ji

[0047] S ii The lateral convergence correction amount of the first pipe segment when the first pipe segment is grouted, in units of m; i

[0048] S ji The lateral convergence correction amount of the first pipe segment when the first pipe segment is grouted, in units of m, the first pipe segment and the second pipe segment are different pipe segments; j i j i

[0049]

[0050] Δ P i The correction pressure on the first pipe segment, in units of MPa, and Δ i P i P i × β P i The grouting pressure when the first pipe segment is constructed, i The cement slurry pressure transmission efficiency coefficient; β

[0051] e i The compaction coefficient between the first pipe segment and the soil body; i

[0052] R i r i + t / 2, in units of m, and r i The grouting pressure when the first pipe segment is constructed, i ​​​​​​​​​​​​​​​​The inner diameter of each segment, t For the first i The horizontal thickness of each segment;

[0053] v ci For the first i Poisson's ratio of concrete for each tunnel segment;

[0054] E ci For the first i The elastic modulus of concrete for each segment, in MPa;

[0055] b i For the first i The thickness of each segment in the horizontal direction is expressed in meters (m).

[0056] f i For the first i Stiffness reduction factor for each tunnel segment;

[0057] ;

[0058] S jj For the first j The lateral convergence correction amount of each segment during grouting is expressed in meters.

[0059] 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;

[0060] 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;

[0061] e j For the first j The compaction coefficient between each pipe segment and the soil;

[0062] R j For the first j The horizontal inner diameter of each segment, in meters;

[0063] v cj For the first j Poisson's ratio of concrete for each tunnel segment;

[0064] E cj For the first j The elastic modulus of concrete for each segment, in MPa;

[0065] b j For the first j The thickness of each segment in the horizontal direction is expressed in meters (m).

[0066] f j For the first j Stiffness reduction factor for each tunnel segment;

[0067] k This is the attenuation factor, with a value ranging from 1 to 2;

[0068] N Other factors may affect the first stage during grouting. i The total number of segments requiring horizontal correction.

[0069] Preferably, step 2) specifically includes the following sub-steps:

[0070] 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.

[0071] 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.

[0072] Preferably, step 2) further comprises the following sub-steps:

[0073] 2.3) constructing all the inclined piles, and during the construction of the inclined piles, the construction of the other inclined piles, except the first constructed inclined pile, is carried out in the following manner: the current constructed inclined pile is spaced apart from the last constructed inclined pile by 4-5 segments.

[0074] According to another aspect of the present application, there is also provided a pile group for correcting the deformation of a shield tunnel beyond the limit, comprising a plurality of pile columns, and formed after the shield tunnel is corrected by the correction method.

[0075] Preferably, the pile group comprises a plurality of first pile column groups, wherein:

[0076] Each of the first pile column groups comprises horizontal pile columns and vertical pile columns, and the horizontal pile columns and the vertical pile columns are horizontal piles and vertical piles, respectively;

[0077] The horizontal piles and the vertical pile of each of the first pile column groups are coplanar;

[0078] The two horizontal piles of each of the first pile column groups are arranged symmetrically left and right on a segment, and the two horizontal piles and the vertical pile of each of the first pile column groups are installed on the same segment of the shield tunnel;

[0079] Any two adjacent first pile column groups are arranged with a spacing of at least one segment.

[0080] Preferably, the pile group comprises a plurality of second pile column groups, wherein:

[0081] Each of the second pile column groups comprises horizontal pile columns and vertical pile columns, and the horizontal pile columns and the vertical pile columns are horizontal piles and vertical piles, respectively;

[0082] The horizontal piles and the vertical pile of each of the second pile column groups are coplanar;

[0083] Each of the second pile column groups further comprises two inclined piles, and the vertical pile is located between the two inclined piles;

[0084] The two inclined piles of each of the second pile column groups are arranged symmetrically left and right on a segment;

[0085] The center lines of the two inclined piles, the vertical pile, and the two horizontal piles of each of the second pile column groups are coplanar;

[0086] The two horizontal piles of the second pile group are symmetrically arranged, the two inclined piles, the vertical pile and the two horizontal piles of each second pile group are arranged on the same segment of the shield tunnel, and any two adjacent second pile groups are arranged at intervals of at least one segment.

[0087] Preferably, the pile group comprises a plurality of third pile groups, wherein:

[0088] Each third pile group comprises a horizontal pile and a vertical pile, and the horizontal pile and the vertical pile are respectively a horizontal pile and a vertical pile;

[0089] The horizontal pile and the vertical pile of each third pile group are one;

[0090] Each third pile group further comprises a pile with a center line inclined to the vertical plane, and the pile with the center line inclined to the vertical plane is an inclined pile, and the inclined pile is one;

[0091] The center lines of the one inclined pile, the one vertical pile and the one horizontal pile of each third pile group are coplanar;

[0092] The one horizontal pile, the one vertical pile and the one inclined pile of each third pile group are arranged on the same segment;

[0093] For any two adjacent third pile groups, the projections of the two inclined piles on the cross section of the segment are symmetrical, and the projections of the two horizontal piles on the cross section of the segment are also symmetrical.

[0094] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0095] 1) The shield tunnel deformation overrun correction method of the present application forms a pile by grouting the soil layer outside the single segment with deformation overrun, the grouting pressure is converted into correction pressure, and directly acts on the segment, thereby realizing fine correction of the deformation of the single segment. Compared with the traditional whole reinforcement method using piles, it is more targeted and can accurately correct the deformation, effectively solving the deformation problem of the shield tunnel.

[0096] 2) The shield tunnel deformation overrun correction method of the present application corrects the segments one by one, which 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 fully and systematically corrected.

[0097] 3) The shield tunnel deformation overrun correction method of the present application, the grouting process not only produces correction pressure on the segment, but also penetrates and solidifies the soil layer outside the segment to form a pile column, thereby improving the physical and mechanical properties of the surrounding soil, increasing the strength and stability of the soil, providing stronger external support for the segment, reducing the influence of soil deformation on the segment, and enhancing the overall stability of the tunnel, fundamentally solving the problem of shield tunnel convergence deformation caused by insufficient soil support, and effectively prolonging the service life of the tunnel, reducing the maintenance cost and frequency.

[0098] 4) The shield tunnel deformation overrun correction method of the present application, by controlling the grouting pressure and other parameters, the size and action time of the correction pressure can be easily adjusted to meet the needs of different segment deformation degrees and geological conditions, the construction process is flexible, and dynamic adjustment can be made according to the actual situation to ensure that the correction effect meets the design requirements.

[0099] 5) The shield tunnel deformation overrun correction method of the present application can improve the surrounding soil and effectively solve the problem of shield tunnel deformation overrun, with a cost reduction of 30% compared to traditional micro-disturbance grouting and steel ring reinforcement from the perspective of the whole life cycle, filling the gap in efficient correction technology in the industry.

[0100] 6) The pile group for shield tunnel convergence deformation correction of the present application adopts a combination of horizontal piles, vertical piles and inclined piles, combines spatial pile groups with shield tunnel stratum reinforcement, breaks through the limitations of traditional single-point reinforcement, and simultaneously corrects and reinforces the shield tunnel. BRIEF DESCRIPTION OF DRAWINGS

[0101] Figure 1 is a schematic view of the construction of two horizontal piles on the segment of the present application;

[0102] Figure 2 is a schematic view of the construction of two horizontal piles and two inclined piles on the segment of the present application;

[0103] Figure 3 is a schematic view of the construction of two horizontal piles and one vertical pile on the segment of the present application;

[0104] Figure 4 is a construction sequence diagram of horizontal piles and vertical piles on the shield tunnel of the present application;

[0105] Figure 5 is a schematic view of the construction of two horizontal piles, one vertical pile and two inclined piles on the segment of the present application;

[0106] Figure 6 is a construction sequence diagram of horizontal piles, vertical piles and inclined piles in one layout on the shield tunnel of the present application;

[0107] Figure 7 A schematic diagram of the construction of a horizontal pile, a vertical pile and an inclined pile on a segment of the invention;

[0108] Figure 8 A construction sequence diagram of the construction of another layout of horizontal piles, vertical piles and inclined piles on a shield tunnel of the invention;

[0109] Figure 9 A schematic diagram of the construction of a pile with an enlarged end on a segment of the invention;

[0110] Figure 10 A process flow diagram of the construction of a pile using the TJS method of the invention.

[0111] In all the drawings, the same reference signs refer to the same technical features, in particular:

[0112] 1, shield tunnel; 11, segment; 2, horizontal pile; 3, vertical pile; 4, inclined pile; 5, reinforcing body; 6, enlarged end. DETAILED DESCRIPTION

[0113] In order to make the object, technical solutions and advantages of the invention clearer and more comprehensible, the invention will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the invention and do not limit the invention. In addition, the technical features involved in each embodiment of the invention described below can be combined with each other as long as they do not conflict with each other.

[0114] REFERENCE Figures 1-9 According to one aspect of the invention, a method for correcting the convergence deformation of a shield tunnel is provided, comprising the following steps:

[0115] 1) A high-pressure jet grouting method is used to grout into the soil layer outside the individual segment 11 of the shield tunnel 1 to form a pile on the outer surface of the segment 11. The grouting pressure during grouting acts on the segment 11 through the soil layer outside the segment 11, thereby generating a correction pressure on the segment 11 to correct the deformation of the segment 11, and further achieving the correction of the deformation of the individual segment 11. The high-pressure jet grouting method (also known as high-pressure rotary jet grouting method) can use the MJS method, the TJS method or other high-pressure jet grouting methods.

[0116] 2) Repeat step 1) until the correction of all out-of-limit deformation segments 11 of the shield tunnel is completed. In this way, the correction of the deformation out-of-limit of the shield tunnel 1 is achieved.

[0117] The shield tunnel 1 is assembled from segments 11. By sequentially correcting the individual segments 11 with deformation out-of-limit, the invention can achieve the correction of the deformation out-of-limit of the entire shield tunnel 1.

[0118] Further, the plurality of piles formed in step 2) include horizontal piles to generate a correction pressure on the segment 11 to correct the lateral convergence deformation of the segment 11 during the grouting to form the horizontal piles, thereby correcting the lateral convergence deformation of the shield tunnel 1.

[0119] and / or;

[0120] The plurality of piles formed in step 2) include vertical piles to generate a correction pressure on the segment 11 to correct the floating or uneven settlement of the segment 11 during the grouting to form the vertical piles, thereby correcting the floating or uneven settlement of the shield tunnel 1; wherein the vertical piles are located above the shield tunnel 1 when correcting the floating of the shield tunnel 1, and the vertical piles are located below the shield tunnel 1 when correcting the uneven settlement of the shield tunnel 1.

[0121] and / or;

[0122] The plurality of piles formed in step 2) include inclined piles relative to the vertical plane to generate a support force on the segment 11 to support the segment 11 obliquely during the grouting to form the inclined piles, thereby supporting the shield tunnel 1 obliquely.

[0123] The construction method of the horizontal piles is as follows:

[0124] 1.1) The high-pressure jet grouting method is used to grout into the soil layer outside the single segment 11 of the shield tunnel 1 to form horizontal piles on the outer circumferential surface of the segment 11, and the grouting pressure during the grouting acts on the segment 11 through the soil layer outside the segment 11, thereby generating a correction pressure on the segment 11 to correct the deformation of the segment 11, and further correcting the lateral convergence deformation of the shield tunnel 1.

[0125] 2.1) Step 1.1) is repeated until the correction of the horizontal deformation of all the segments 11 is completed, in this way, the correction of the lateral convergence deformation of the shield tunnel 1 is completed.

[0126] The construction method of the vertical piles is as follows:

[0127] 1.1.1) The high-pressure jet grouting method is used to grout into the soil layer outside the single segment 11 of the shield tunnel 1 to form vertical piles on the outer circumferential surface of the segment 11, and the grouting pressure during the grouting acts on the segment 11 through the soil layer outside the segment 11, thereby generating a correction pressure on the segment 11 to correct the floating or settlement of the segment 11, and further correcting the floating or uneven settlement of the shield tunnel 1; wherein the vertical piles are located above the shield tunnel 1 when correcting the floating of the shield tunnel 1, and the vertical piles are located below the shield tunnel 1 when correcting the uneven settlement of the shield tunnel 1.

[0128] 2.1.1) Repeat step 1.1.1) until the correction of the floating or uneven settlement of all the segments 11 set is completed, in this way, the correction of the floating or uneven settlement of the shield tunnel 1 is completed.

[0129] By grouting the soil layer outside the segment 11 to form a vertical pile, the correction pressure generated by the grouting pressure can accurately correct the floating or settlement of a single segment 11. For the floating of the shield tunnel 1, a vertical pile is formed above to generate a downward pressure for correction; for the settlement, a vertical pile is formed below to generate an upward supporting force for correction. This targeted vertical correction method can effectively solve the problem of floating or uneven settlement of the segment 11, restore the normal axis position and elevation of the tunnel, ensure the smooth operation of vehicles such as trains in the tunnel, and reduce the safety hazards and operation risks caused by floating or uneven settlement.

[0130] By correcting the floating or uneven settlement of all the segments 11 set, the correction of the floating or uneven settlement of the shield tunnel 1 is completed, thereby improving the vertical stability of the entire shield tunnel 1. After correction, the tunnel is more uniform and reasonable in vertical stress, reducing the accumulation of vertical deformation caused by local stress concentration or insufficient bearing capacity of the soil body, and enhancing the ability of the tunnel to resist external loads and environmental changes, such as reducing the influence of factors such as changes in groundwater level, surrounding engineering construction, on the vertical stability of the tunnel, improving the safety and reliability of the tunnel, and prolonging the service life of the shield tunnel 1.

[0131] The formation of the vertical pile also improves the surrounding soil. The grouting material fills the pores of the soil, making the soil and the pile form a composite foundation with better integrity, improving the vertical bearing capacity and deformation resistance of the soil. This not only provides more reliable vertical support for the segment 11, but also improves the interaction between the tunnel and the soil, allowing the tunnel to better adapt to changes in the soil environment during operation, reducing secondary deformation of the tunnel caused by factors such as soil settlement or uplift.

[0132] The construction method of forming an inclined pile is as follows:

[0133] 1.1.1.1) A high-pressure jet grouting method is used to grout the soil layer outside the single segment 11 of the shield tunnel 1 to form a pile inclined to the vertical plane on the outer surface of the segment 11. The grouting pressure during grouting acts on the segment 11 through the soil layer outside the segment 11, thereby generating a supporting force on the segment 11 to support the segment 11 obliquely, and then achieving oblique support of the single segment 11.

[0134] 2.1.1.1) Repeat step 1.1.1.1) until the oblique support of all segments 11 is completed, in this way, the oblique support of the shield tunnel 1 is completed.

[0135] By grouting the inclined pile outside the segment 11 to form a relatively vertical surface, the segment 11 is provided with an oblique support force, thereby achieving the oblique support of the shield tunnel. This oblique support can effectively resist the oblique deformation of the segment 11 under complex stress environment, enhance the stability of the segment 11 in all directions in space, make up for the deficiency of pure horizontal and vertical correction, make the stress system of the segment 11 more perfect, improve the overall stability and carrying capacity of the tunnel structure, and better adapt to the requirements of different geological conditions and construction environment on the tunnel structure.

[0136] The plurality of inclined piles, horizontal piles and vertical piles cooperate with each other to form a spatial pile group structure, which greatly enhances the overall stiffness of the shield tunnel 1. When the tunnel is subjected to external loads, such as impact force generated by passing trains, pressure change of surrounding soil, etc., this rigid frame structure can more effectively disperse and conduct stress, reduce local stress concentration phenomenon, reduce the risk of cracking and deformation of the segment 11, ensure the structural safety and stability of the tunnel during long-term operation, and reduce the maintenance and repair workload caused by insufficient structural stiffness.

[0137] By controlling the grouting pressure and sequence of the pile construction process, the purpose of correcting the deformed tunnel is achieved. The construction sequence is: horizontal pile 2→ vertical pile 3→ inclined pile 4, that is, all horizontal piles 2 are constructed first, then all vertical piles 3 are constructed, and finally all inclined piles 4 are constructed.

[0138] According to the deformation correction practice of a certain interval tunnel of Harbin Line 1, using this method, the tunnel settlement correction amplitude can reach 15%~45%, and the transverse convergence deformation correction amplitude of the shield tunnel 1 can reach 5%~40%.

[0139] Further, in step 1), before grouting by high-pressure jet grouting method, the service state of the shield tunnel is determined based on the monitored segment deformation data, then the correction target of the deformed segment 11 is set according to the service state of the shield tunnel, and finally the design scheme and construction process of the pile group are determined, wherein the pile group is a spatial combination of pile columns on the outer surface of the shield tunnel.

[0140] Preferably, in step 1), the control method of grouting pressure is as follows:

[0141] 1a) Grouting is carried out in the soil layer with a set grouting pressure and back pressure for a set time, and then the displacement of the side wall of the segment 11 is measured;

[0142] 1b) compare the measured value of the displacement of the sidewall of the segment 11 with the target value of the displacement of the sidewall of the segment 11, if the measured value is less than the target value, increase the set grouting pressure and / or decrease the back grouting pressure, and then return to step 1a; if not less than the target value, continue grouting according to the grouting pressure set in step 1a.

[0143] Back grouting is the process of discharging grout outside the hole to regulate the pressure in the soil layer. The back grouting pressure in high-pressure grouting is controlled by a pressure balance tank, and the pressure gauge on the tank can be read. During grouting, the cement grout will press the soil layer, and the soil layer will also react on the segment. By controlling the force of the cement grout acting on the segment through back grouting, the over-high pressure in the soil layer is avoided, which can cause soil disturbance or deterioration of segment deformation, thereby playing a role in precise correction.

[0144] By dynamically adjusting the grouting pressure and / or back grouting pressure, precise control of the correction pressure can be achieved. This ensures that the pressure received by the segment 11 during the correction process matches the deformation degree and the required correction amount, avoiding the problem of excessive force on the segment 11 due to excessive grouting pressure, or insufficient correction effect due to insufficient pressure, improving the accuracy and reliability of the correction, and ensuring that the final correction effect meets the design and construction requirements.

[0145] The grouting pressure control method is based on actual measurement data for feedback adjustment, which can timely discover and correct the deviation of grouting pressure in construction, ensuring the continuity and stability of grouting construction, avoiding the problems of construction interruption or rework caused by excessive pressure fluctuation, improving the construction efficiency, shortening the construction period, reducing the construction cost, and also reducing the impact on normal operation of the tunnel and the surrounding environment caused by the long construction period.

[0146] Further, for the mechanism of tunnel deformation correction under grouting, firstly, the stratum, grouting parameters and other factors should be considered comprehensively to study the relationship between grouting pressure and load transmitted to the tunnel segment. Then, the principle of minimum potential energy is used to establish a model of strain energy of tunnel structure deformation and external work caused by grouting. The strain energy is divided into rigid deformation caused by segment joint rotation and flexible deformation caused by segment bending. The external work is composed of work done by grouting pressure directly acting on the segment and compaction effect of the composite stratum (after grouting). Finally, the traditional single load-structure model or stratum-structure model is combined and unified.

[0147] According to the above tunnel deformation correction mechanism, a simplified calculation is performed for the segment deformation correction of the shield tunnel.

[0148] Further, in step 2), only one pile is formed by grouting each time, and a batch of vertical piles are formed in sequence according to the construction sequence, and the segment for which the first grouting is performed for the correction of the floating or uneven settlement is the segment for which the second grouting is performed for the correction of the floating or uneven settlement. i ​i Vertical displacement of a single tunnel segment δ i The calculation method is as follows:

[0149] δ i = δ ii + δ ji ;

[0150] in,

[0151] δ i For the first i The total vertical correction amount for each segment, in meters;

[0152] δ ii For the first i The vertical correction amount of each segment during grouting is expressed in meters (m).

[0153] 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:

[0154] ;

[0155] 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.

[0156] 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;

[0157] A 1i To correct the pressure acting on the first iEffective action area per meter of the reinforcing body of a pipe piece, unit: m², the reinforcing body is the end of the pile column in contact with the pipe piece and the end is the thickened end;

[0158] K vi is the ground reaction force coefficient of the side of the i th pipe piece, unit: kN / m³, which needs to be tested or valued by experience on site;

[0159] e i is the compaction coefficient between the i th pipe piece and the soil, which needs to be tested or valued by experience on site;

[0160] A 2i is the effective action area per meter of the soil on the side opposite to the pile column of the shield tunnel, unit: m²;

[0161] ;

[0162] δ jj is the vertical correction amount of the j th pipe piece when grouting, unit: m;

[0163] d ji = L ji + L 0 , wherein L ji is the distance between the j th pipe piece and the i th pipe piece, L 0 is the axial length of a single pipe piece, d ji , L ji and L 0 , the j th pipe piece and the i th pipe piece are different pipe pieces;

[0164] k is the attenuation factor, the value is 1-2;

[0165] n is the total number of other pipe pieces that will affect the vertical correction amount of the i th pipe piece when grouting;

[0166] c j is the ground reaction force coefficient of the side of the jThe other segment beside the segment j The constraint influence coefficient of the segment needs to be tested on site or valued by experience.

[0167] Δ P j The correction pressure on the segment j is MPa, and Δ P j P j × β , P j The grouting pressure during the construction of the segment j is β The cement slurry pressure transmission efficiency coefficient;

[0168] A 1j The effective action area per meter of the reinforcing body on which the correction pressure of the segment j acts, is m2, and the reinforcing body is the end of the pile column in contact with the segment and the end is thickened;

[0169] K vj The ground reaction coefficient beside the segment j is kN / m3, and needs to be tested on site or valued by experience.

[0170] e j The compaction coefficient between the segment j and the soil needs to be tested on site or valued by experience.

[0171] A 2j The effective action area per meter of the soil on the side opposite to the pile column of the shield tunnel is m2.

[0172] Further, in step 2), only one pile column is formed each time, and a batch of horizontal pile columns are formed in sequence according to the construction sequence, and the segment i for which the transverse convergence correction is performed by the segment i for which the transverse convergence correction is performed is the segment i , and the transverse convergence is the deformation in the horizontal direction, so the transverse convergence correction amount is the horizontal correction amount, and the total correction amount of the transverse convergence of the segment S i is calculated as follows:

[0173] S i S ii + S ji ;​​

[0174] S ii For the first i The lateral convergence correction amount of each segment during grouting is expressed in meters.

[0175] 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;

[0176] ;

[0177] 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;

[0178] 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.

[0179] 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;

[0180] v ci For the first i Poisson's ratio of concrete for each tunnel segment;

[0181] E ci For the first i The elastic modulus of concrete for each segment, in MPa;

[0182] bi For the first i The thickness of each segment in the horizontal direction is expressed in meters (m).

[0183] f i For the first i Stiffness reduction factor for each tunnel segment;

[0184] ;

[0185] S jj For the first j The lateral convergence correction amount of each segment during grouting is expressed in meters.

[0186] 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;

[0187] 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;

[0188] 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.

[0189] R j For the first jThe inner diameter of the pipe piece in the horizontal direction, in units of m;

[0190] v cj The concrete Poisson's ratio of the first j

[0191] E cj The concrete elastic modulus of the first j

[0192] b j The thickness of the first j

[0193] f j The stiffness reduction coefficient of the first j

[0194] k The attenuation factor, taking a value of 1-2;

[0195] N The total number of other pipe pieces that will affect the horizontal correction amount of the first i

[0196] Further, with reference to Figure 10 , if the TJS method is used to construct the pile, the specific process is as follows:

[0197] b1, lofting: according to the design drawing, the original grouting hole axis of the pipe piece 11 and the hole position on the pipe piece 11 that needs to be newly opened are determined according to the actual situation on site, and paint spraying and steel nails are preferably used to mark well to determine the pile position; if the existing lining grouting hole or hoisting hole is used, no hole needs to be opened.

[0198] b2, if the original grouting hole on the pipe piece 11 is directly used for grouting, step S3 is entered;

[0199] ​​​​​If the grouting hole is re-opened on the pipe segment 11, the specific steps are as follows: the hole is opened to the inner wall of the protective layer of the pipe segment 11, then the drill is pulled out, a sleeve is placed at the opening of the pipe segment 11, and epoxy resin or glue is injected between the sleeve and the hole wall of the newly opened hole (two working conditions are handled when the sleeve is placed, the first working condition is that the ballast bed is found to be empty after the hole is newly opened, and the sleeve wall and the newly opened hole wall are injected with epoxy resin; the second working condition is that the ballast bed is not empty after the hole is newly opened, and then glue is injected), then a sealing and plugging device is installed on the rear sleeve to prevent soil and sand from gushing out during the opening process and cement slurry from gushing out during the construction process, and finally a manual water drill is used to drill from the hole sealing and plugging device and penetrate the protective layer of the pipe segment 11 until the drill bit of the manual water drill contacts the undisturbed soil outside the pipe segment 11, and then the manual water drill used for opening is pulled out.

[0200] If the pile column is a vertical pile 3, the opening position of the vertical pile 3 is the middle part of the ballast bed.

[0201] During the opening process, when the drill is about to reach the protective layer outside the pipe segment, the drilling is stopped, and the sealing and plugging device is installed in time.

[0202] The sealing and plugging device includes a gate valve, a sealing device and other components. If the existing lifting hole and grouting hole of the pipe ring are used, the end of the gate valve is connected to the thread of the existing lifting hole and grouting hole through a sleeve. If a new hole is opened, the sleeve is fixed after the rear sleeve is placed, and then the gate valve is installed on the hole seat with threads.

[0203] The rear sleeve of the newly opened hole is sealed and connected to the inner wall of the tunnel through a sealing gasket, the end of the sleeve is threaded to connect the gate valve, and the gate valve is connected to the sealing device through bolts. The bolt connection between the gate valve and the sealing device is also provided with a sealing gasket to prevent soil and sand from gushing out during the opening process and cement slurry from gushing out during the construction process.

[0204] b3, main machine installation: according to the axis and hole position determined in step S1, the main machine of the operation platform is moved to the position, the data line is connected, the position and direction of the main machine are adjusted, the center of the drill bit of the main machine is aligned with the axis or hole position, the deviation between the center of the drill bit and the pile position is ensured to be within the set range, preferably the deviation is not greater than 10 mm, and then the operation platform is fixed firmly.

[0205] b4, hole drilling: high-pressure water is used for hole drilling; during the hole drilling process, the robot rod connecting device connects the rods, the high-pressure water is temporarily turned off every time a drill rod is jacked, and the robot rod connecting device performs the rod connecting operation of the next drill rod. During the rod connecting process, it is carefully checked whether the sealing ring is missing or damaged and whether the ground pressure display is normal.

[0206] During the vertical hole drilling construction process, in order to prevent the hole wall from collapsing and burying the drill, especially when drilling in sandy soil layers, bentonite mud wall protection drilling should be used, and the viscosity of the bentonite mud should be not less than 19 s.

[0207] b5, configure the cement slurry: according to the set water-cement ratio, mix the cement slurry, and after the cement slurry is filtered, it is pumped by the high-pressure pump to the operation platform for jetting operation without interruption.

[0208] Specifically, when the hole is drilled to the designed elevation, the cement slurry is configured 20 minutes in advance. The automatic mixing mode is adopted, the mixing parameters are set, and the cement slurry is mixed according to the set water-cement ratio. When the cement slurry is configured, the upper mixing tank is equipped with an automatic batching system. After uniform mixing, the discharge switch is turned on, the cement slurry is discharged to the lower mixing tank through the filter screen, the lower mixing system switch is turned on, and the secondary mixing of the cement slurry in the lower storage tank is carried out. After filtration, it is pumped by the high-pressure pump to the front desk for jetting operation without interruption.

[0209] b6, jet grouting: first construct a circumferential cushion layer on the outer wall of the segment 11, then construct a pile, and let the grouting pressure during the construction of the pile produce a correction pressure on the segment 11 to correct the deformation of the segment 11. The grouting parameters are shown in Table 1.

[0210] Table 1 Grouting parameter table

[0211]

[0212] Specifically, after the drill bit reaches the predetermined depth, the process parameters are set. After all the data are normal, the water is immediately switched to the cement slurry, and after the drill rod is repositioned, the drill rod is pulled out and jet grouting is started.

[0213] During the jet grouting process, waste slurry recycling is also required. The usable waste slurry can be added to the cement slurry for jet grouting, and the unusable waste slurry can be treated as waste after the slurry solidifies and the equipment is removed.

[0214] b7, digital tracking grouting: first construct a pile, then track the gap between the later pile and the segment 11 and fill the gap with grouting to control the deformation of the shield tunnel 1.

[0215] Specifically, the radial cement-soil pile reinforcement technology of the shield tunnel is divided into two stages. The first stage is the process of forming the radial cement-soil pile, and the second stage is the process of digital tracking grouting. Because there will be a gap between the top of the cement-soil pile and the segment, the gap is grouted in time to control the deformation of the tunnel during the process, and double liquid slurry is used for secondary grouting.

[0216] b8, sealing maintenance: close the gate valve of the sealing blowout preventer, after the cement slurry is completely solidified, open the gate valve to observe whether there is slurry leakage phenomenon, if not, remove the sealing blowout preventer, then seal the grouting hole on the segment 11; if so, reopen the gate valve of the sealing blowout preventer, and supplement the grouting treatment to the slurry leakage part until the cement slurry is completely solidified and no slurry leakage phenomenon is found again, then remove the sealing blowout preventer and seal the grouting hole on the segment 11.

[0217] For the grouting hole of the existing segment, the grouting hole can be plugged by the grouting hole plugging method: the segment 11 is provided with a grouting hole embedded part, the grouting hole embedded part surrounds the grouting hole, and the grouting hole is filled and compacted by injecting cement slurry, and after the cement slurry is solidified, a plug is installed at one end of the grouting hole embedded part close to the inner arc surface of the segment, and the plug is threadedly connected with the grouting hole embedded part.

[0218] For the newly opened grouting hole, after the gate valve is removed, the inside of the sleeve is filled with C30 sulphoaluminate cement with micro-expansion, and the end of the sleeve is sealed with a threaded plug, and a waterproof adhesive tape is wound on the threaded plug to prevent leakage.

[0219] According to another aspect of the present application, a pile column for correcting the convergence deformation of a shield tunnel is also provided, which is formed after the shield tunnel 1 is corrected by the correction method.

[0220] The pile column formed by using the above correction method is not only a direct result of the deformation correction of the segment 11, but also forms a composite structure with the surrounding soil body, which has good mechanical properties and stability. This pile column can stably provide support and restraint to the segment 11 for a long time, effectively resist various internal and external loads acting on the tunnel during operation, prevent the segment 11 from deforming again, and ensure the geometric shape and structural stability of the tunnel, thereby providing reliable protection for the safe operation of urban rail transit.

[0221] Further, for the case that the constructed pile column is a vertical pile 3 and an inclined pile 4, an enlarged end 6 is arranged on the vertical pile 3 and the inclined pile 4, and the diameter of the enlarged end 6 is enlarged relative to other parts of the pile column.

[0222] During the correction of the convergence deformation of the shield tunnel, the enlarged end 6 can provide 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, so that the segment 11 can more accurately displace according to the design requirements, thereby realizing more accurate deformation correction. For example, when the horizontal deformation of the segment is corrected, the enlarged end 6 on the horizontal pile column can more firmly resist the soil body, so that the grouting pressure can be more effectively converted into lateral thrust on the segment, thereby promoting the segment to return to the correct horizontal position.

[0223] The existence of the enlarged end 6 helps to maintain the corrected state after correction is completed. It is like a stable "anchor point" that can prevent the segment from deforming again due to uneven settlement of the soil, train vibration and other factors during subsequent use, ensuring the long-term effectiveness of the correction effect, reducing the possibility of secondary correction due to repeated deformation, and reducing maintenance costs and construction risks.

[0224] The enlarged area of the enlarged end 6 can better disperse the force borne by the pile into the surrounding soil. It avoids the stress of the soil being too concentrated due to the pile being too thin, thereby causing local damage or deformation of the soil. This stress dispersion helps to improve the stress state of the soil and improve the overall stability of the soil, enabling the soil around the shield tunnel to bear external loads more evenly, reducing the adverse effects of the soil on the tunnel, and creating good geological conditions for the long-term safe operation of the tunnel.

[0225] The existence of the enlarged end 6 makes the combination between the pile and the soil more compact, 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, taking advantage of the synergistic effect of the pile and the soil layer. 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, further enhancing the reliability and durability of the tunnel structure.

[0226] Due to the increased contact area and friction between the pile and the soil caused by the enlarged end 6, the pile has better embedded effect in the soil. After construction is completed, it can effectively reduce the risk of pile inclination or fracture caused by uneven settlement of the soil, ensuring the quality and service life of the pile, and also ensuring the structural quality of the shield tunnel, avoiding tunnel deformation or other structural diseases caused by pile problems, and prolonging the service life of the tunnel.

[0227] In the long term, the design of the enlarged end 6 helps to reduce the maintenance cost of the tunnel. It enhances the supporting capacity and durability of the pile, reducing the repair and replacement work due to pile failure or deformation.

[0228] According to another aspect of the present application, a shield tunnel over-limit deformation correction pile group is also provided, which includes a plurality of pile columns and is formed after the pile columns are corrected by the correction method.

[0229] As a preferred solution, the pile group includes a plurality of first pile column groups, wherein:

[0230] Each of the first pile column groups includes a plurality of the pile columns, 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 all intersect with the center line of the segment 11.

[0231] Each group of the first pile group has two horizontal piles 2 and one vertical pile 3;

[0232] The center lines of the two horizontal piles 2 and the vertical pile 3 of each group of the first pile group are coplanar;

[0233] The two horizontal piles 2 of each group of the first pile group are symmetrically arranged on the segment 11, and the two horizontal piles 2 and the vertical pile 3 of each group of the first pile group are installed on the same segment 11 of the shield tunnel 1;

[0234] Any two adjacent groups of the first pile group are arranged with an interval of at least one segment 11.

[0235] The layout design of the first pile group enables each pile group to effectively constrain and correct the horizontal and vertical deformation of the segment 11, while ensuring a reasonable force transmission path and balanced stress. The adjacent pile groups are arranged with an interval of at least one segment 11, avoiding stress interference and excessive soil disturbance caused by excessive pile density, ensuring that each pile group can function independently, while forming an organic whole as a whole, jointly undertaking the task of correcting and reinforcing the tunnel, and improving the correction effect and structural stability.

[0236] The construction method of the pile group formed by the first pile group comprises the following steps:

[0237] c1) All horizontal piles 2 are constructed first, and during the construction of the horizontal piles 2, except for the first horizontal pile 2, the construction of the other horizontal piles 2 is carried out in the following manner: the horizontal pile 2 under construction is spaced 4-5 segments 11 apart from the last horizontal pile 2, and the projection of the horizontal pile 2 under construction on the cross section of the segment 11 is symmetrical with the last horizontal pile 2.

[0238] c2) All vertical piles 3 are constructed, and during the construction of the vertical piles 3, except for the first vertical pile 3, the construction of the other vertical piles 3 is carried out in the following manner: the vertical pile 3 under construction is spaced 4-5 segments 11 apart from the last vertical pile 3. Referring to Figure 4 , Z1-Z5 are the construction sequence of the vertical piles 3, Z1 is the first vertical pile 3, Z2 is the second vertical pile 3, and so on; S1-S10 are the construction sequence of the horizontal piles 2, S1 is the first horizontal pile 2, S2 is the second horizontal pile 2, and so on.

[0239] In the construction method, all horizontal piles 2 are constructed first, then vertical piles 3 are constructed, and the interval and projection symmetry requirements of the subsequent horizontal piles 2 and vertical piles 3 are specified except for the first construction. This orderly construction sequence is conducive to reasonable arrangement of construction progress, full use of the preliminary reinforcement effect of the pile formed in the early construction on the tunnel, and provision of a more stable environment for subsequent construction. At the same time, the interval and symmetry construction requirements can avoid stress concentration and uneven deformation of the soil during construction, reduce additional deformation of the tunnel caused by construction and the influence on the surrounding environment, and reduce the construction risk.

[0240] As a preferred solution, the pile group comprises a plurality of groups of second pile groups, wherein:

[0241] Each group of the second pile groups comprises a plurality of the pile columns, which include horizontal piles 2 and vertical piles 3, and the center lines of the horizontal piles 2 and the vertical piles 3 intersect the center line of the segment 11.

[0242] The horizontal piles 2 of each group of the second pile groups are two and the vertical piles 3 are one.

[0243] Each group of the second pile groups further comprises two inclined piles 4 and the vertical pile 3 is located between the two inclined piles 4.

[0244] The two inclined piles 4 of each group of the second pile groups are arranged symmetrically on the segment 11.

[0245] The center lines of the two inclined piles 4, the vertical pile 3 and the two horizontal piles 2 of each group of the second pile groups are coplanar.

[0246] The two horizontal piles 2 of the second pile groups are symmetrically arranged, the two inclined piles 4, the vertical pile 3 and the two horizontal piles 2 of each group of the second pile groups are installed on the same segment 11 of the shield tunnel 1, and any two adjacent groups of the second pile groups are arranged at an interval of at least one segment 11.

[0247] The design of the second pile group makes each group of pile groups not only have the correction ability in the horizontal and vertical directions, but also increase the inclined support force, which can more comprehensively resist the deformation of the segment 11 in various directions in space, improve the support stiffness and stability of the pile group to the segment 11. The synergistic effect of the inclined piles 4, the vertical piles 3 and the horizontal piles 2 forms a spatial three-dimensional support system, enhances the overall bearing capacity and anti-deformation capacity of the pile group, and better adapts to the changing needs of complex geological conditions and tunnel stress environment.

[0248] The construction method of the pile group formed by the second pile group comprises the following steps:

[0249] d1) all the horizontal piles 2 are constructed first, and during the construction of the horizontal piles 2, the construction of the other horizontal piles 2, except the first constructed horizontal pile 2, is performed in the following manner: the current constructed horizontal pile 2 is spaced apart from the last constructed horizontal pile 2 by 4-5 segments 11, and the current constructed horizontal pile 2 is symmetric to the last constructed horizontal pile 2 in the projection of the segments 11 on the cross section.

[0250] d2) all the vertical piles 3 are constructed again, and during the construction of the vertical piles 3, the construction of the other vertical piles 3, except the first constructed vertical pile 3, is performed in the following manner: the current constructed vertical pile 3 is spaced apart from the last constructed vertical pile 3 by 4-5 segments 11.

[0251] d3) all the inclined piles 4 are constructed last, and during the construction of the inclined piles 4, the construction of the other inclined piles 4, except the first constructed inclined pile 4, is performed in the following manner: the current constructed inclined pile 4 is spaced apart from the last constructed inclined pile 4 by 4-5 segments 11, and the current constructed inclined pile 4 is symmetric to the last constructed inclined pile 4 in the projection of the segments 11 on the cross section. Referring to Figure 6 , Z1-Z3 are the construction sequences of the vertical piles 3, Z1 is the first constructed vertical pile 3, Z2 is the second constructed vertical pile 3, and so on; S1-S6 are the construction sequences of the horizontal piles 2, S1 is the first constructed horizontal pile 2, S2 is the second constructed horizontal pile 2, and so on; X1-X6 are the construction sequences of the inclined piles 4, X1 is the first constructed inclined pile 4, X2 is the second constructed inclined pile 4, and so on.

[0252] The present application constructs the horizontal piles 2 first, then constructs the vertical piles 3, and finally constructs the inclined piles 4, and the subsequent construction interval and symmetry requirement of each pile are specified. Such construction organization arrangement is conducive to the rational allocation of construction resources, avoids mutual interference in the construction process of different piles, and ensures the construction quality and efficiency of each pile. At the same time, through symmetrical construction and interval arrangement, the stress generated in the construction process can be gradually balanced and released, the tunnel deformation and soil disturbance caused by improper construction sequence are reduced, and the smooth progress of the construction process and the safety and stability of the tunnel structure are ensured.

[0253] As another preferred embodiment, the pile group comprises a plurality of third pile groups, wherein:

[0254] Each of the third pile groups comprises a plurality of pile columns, and the pile columns comprise horizontal piles 2 and vertical piles 3, and the center lines of the horizontal piles 2 and the vertical piles 3 intersect the center line of the segment 11.

[0255] The horizontal piles 2 and the vertical piles 3 of each of the third pile groups are one.

[0256] Each of the third pile groups further comprises an inclined pile 4, and an angle is formed between the inclined pile 4 and the vertical pile 3.

[0257] The center lines of the inclined pile 4, the vertical pile 3 and the horizontal pile 2 of each of the third pile groups are coplanar.

[0258] The inclined pile 4, the vertical pile 3 and the horizontal pile 2 of each of the third pile groups are installed on the same segment 11.

[0259] For any two adjacent third pile groups, 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.

[0260] Each of the third pile groups is composed of a horizontal pile 2, a vertical pile 3 and an inclined pile 4, which has a relatively simple structure but complete functions. The reduction in the number of each type of pile makes the layout of the pile group more compact, reducing the occupation of tunnel space and the disturbance range of the soil body. At the same time, each pile group is installed on the same segment 11 of the shield tunnel 1, which is convenient for construction positioning and operation, improves the construction efficiency and construction accuracy, reduces the construction cost and construction difficulty, and is especially suitable for the correction engineering of the shield tunnel 1 with limited space or complex geological conditions.

[0261] The projections of the inclined piles 4 and the horizontal piles 2 of the two adjacent third pile groups on the cross section of the segment 11 are symmetrical, and the center lines of the vertical piles 3 all intersect with the center line of the segment 11. This symmetrical design ensures the uniform distribution of the force of the pile group around the segment 11, avoids the problems of local stress concentration and tunnel deviation caused by the asymmetric arrangement of the piles, and improves the stability and correction effect of the entire pile group. The symmetrical structure is also conducive to the better adaptation of the pile group to the dynamic deformation and vibration caused by the train load during the operation process, enhancing the reliability and durability of the tunnel structure.

[0262] The construction method of the pile group formed by the third pile groups comprises the following steps:

[0263] e1) All the horizontal piles 2 are constructed first, and during the construction of the horizontal piles 2, the construction of the other horizontal piles 2, except for the first constructed horizontal pile 2, is carried out in the following manner: the horizontal pile 2 under construction is spaced 4-5 segments 11 apart from the last constructed horizontal pile 2, and the projection of the horizontal pile 2 under construction on the cross section of the segment 11 is symmetrical with the last constructed horizontal pile 2.

[0264] e2) re-construction of all vertical piles 3, and during the construction of the vertical piles 3, in addition to the first constructed vertical pile 3, the construction of other vertical piles 3 is carried out in the following manner: the current constructed vertical pile 3 is spaced 4-5 segments 11 from the last constructed vertical pile 3.

[0265] e3) final construction of all inclined piles 4, and during the construction of the inclined piles 4, in addition to the first constructed inclined pile 4, the construction of other inclined piles 4 is carried out in the following manner: the current constructed inclined pile 4 is spaced 4-5 segments 11 from the last constructed inclined pile 4, and the current constructed inclined pile 4 is symmetric to the last constructed inclined pile 4 in the projection of the segments 11 in the cross section. See Figure 8 , Z1-Z5 are the construction sequences of the vertical piles 3, Z1 is the first constructed vertical pile 3, Z2 is the second constructed vertical pile 3, and so on; S1-S9 are the construction sequences of the horizontal piles 2, S1 is the first constructed horizontal pile 2, S2 is the second constructed horizontal pile 2, and so on; X1-X9 are the construction sequences of the inclined piles 4, X1 is the first constructed inclined pile 4, X2 is the second constructed inclined pile 4, and so on.

[0266] The construction method of the pile group formed by the third pile group requires that the current constructed horizontal pile 2 and inclined pile 4 are symmetric to the last constructed pile of the same type in the projection of the segments 11 in the cross section, which helps to ensure the uniform distribution of the force around the segments 11, avoids local stress concentration and tunnel deviation caused by the asymmetric arrangement of the piles, and improves the stability and correction effect of the entire pile group. By adopting reasonable construction sequences and spacing requirements, the construction of the piles in the same area is avoided, thereby reducing the 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 influence of the construction on the surrounding environment.

[0267] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

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. This method corrects the excessive deformation of the shield tunnel. Each time, only one pile is formed through grouting. Grouting is performed sequentially according to the construction sequence to form a batch of vertical piles, and the process continues until the first pile is completed. 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 during grouting, 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.

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), 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 during 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.

6. 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.

7. The method for correcting excessive deformation in shield tunnels according to claim 6, 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.

8. 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 7.

9. The shield tunnel deformation over-limit correction pile group according to claim 8, 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.

10. The shield tunnel deformation over-limit correction pile group according to claim 8, 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.

11. The shield tunnel deformation over-limit correction pile group according to claim 8, 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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