Deviation rectifying and resetting method for bridge pile foundation

Abstract

The invention provides a bridge pile foundation deviation rectifying and resetting method. A grouting hole is formed in a stratum soil body on the deviation side, a cement-soil wall is arranged in the stratum soil body on the side, away from a bridge pile foundation, of the grouting hole, deep grouting is conducted in the grouting hole, and the bridge pile foundation is driven to reset through grouting pressure. The pressure relief holes are formed in the stratum soil body on the reset side, reset force is provided for resetting of the bridge pile foundation in a deep grouting mode, the reset force is evenly transmitted to all positions of the pile body through the stratum soil body, and pile body inflection can be effectively avoided; and meanwhile, the parabolic cement-soil wall is arranged on the side, away from the bridge pile foundation, of the grouting hole, the cement-soil wall is used for providing the counter-force effect, and the effective reset force is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge deviation correction, and in particular relates to a method for correcting and resetting a bridge pile foundation. Background Art

[0002] In soft soil areas, bridge pile foundations often undergo horizontal displacement, which affects the normal use of the bridge pile foundations. In severe cases, it can also cause the upper structure supported by the bridge pile foundations to fall, posing a huge safety hazard. Once a bridge is displaced during construction, it needs to be reset.

[0003] In the related art, the commonly used reset construction method is generally to apply horizontal thrust to the top of the bridge pile foundation on the surface to forcibly drive the bridge pile foundation to reset. This method can easily cause the upper part of the bridge pile foundation to bend inward, and when the degree of bending is too large, it can easily cause the pile body to break.

[0004] Therefore, it is necessary to provide a method for correcting and resetting the deviation of a bridge pile foundation to solve the problems raised in the above-mentioned background technology. Summary of the invention

[0005] The present invention provides a method for correcting and resetting a bridge pile foundation, which provides a resetting force for resetting the bridge pile foundation by deep grouting, and utilizes the stratum soil to evenly transmit the resetting force to various parts of the pile body, thereby effectively avoiding the pile body from bending back. At the same time, a parabolic cement soil wall is arranged on the side of the grouting hole away from the bridge pile foundation, and the cement soil wall is utilized to provide a reaction force to ensure the size of the effective resetting force, thereby effectively solving at least one technical problem involved in the background technology.

[0006] In order to solve the above-mentioned technical problems, the present invention is achieved as follows: A method for correcting and resetting a bridge pile foundation comprises the following steps: Step S1, selecting a bridge pile foundation correction and reset scheme: setting a grouting hole in the stratum soil on the deviated side, setting a cement soil wall in the stratum soil on the side of the grouting hole away from the bridge pile foundation, deep grouting in the grouting hole, and using the grouting pressure to drive the bridge pile foundation to reset; setting a pressure relief hole in the stratum soil on the reset side; Step S2, determining the shape of the cement soil wall and the position of the grouting holes: the cement soil wall is parabolic, the arching direction is consistent with the deviation direction of the bridge pile foundation, the grouting holes and the bridge pile foundation are both located on the horizontal axis of the cement soil wall, and the grouting holes are located at the focal position of the cement soil wall; Step S3, using the energy variation principle to derive the relationship between the restoring force on the bridge pile foundation and the grouting pressure and the bridge pile foundation restoring amount; Step S4, for any bridge pile foundation deviation correction and resetting process, based on the resetting amount required for the bridge pile foundation, the grouting pressure value is assumed, and the theoretical resetting force generated by the grouting is calculated by the relationship provided in step S3; the interaction force generated by the stratum soil and the bridge pile foundation during the resetting process is calculated based on the empirical formula, and the interaction force value is used as the verification factor of the theoretical resetting force. If the theoretical resetting force value is greater than the verification factor, the interaction force value corresponding to the verification factor is taken as the theoretical resetting force value; otherwise, the theoretical resetting force value is retained; Step S5, according to the determined theoretical reset force value, the pile displacement is calculated by a numerical calculation method, and the top displacement of the bridge pile foundation is determined based on the calculated pile displacement, and it is judged whether the error between the top displacement and the required reset amount is not greater than 5%. If so, the assumed value of the grouting pressure is taken as the actual grouting pressure; otherwise, the process returns to step S4 and the grouting pressure value is re-assumed for trial calculation until the error between the top displacement of the bridge pile foundation and the required reset amount is not greater than 5%; Step S6, deep grouting is performed in the grouting hole with actual grouting pressure, and the bridge pile foundation is driven to reset by the grouting pressure.

[0007] As a preferred improvement, the cement soil wall is constructed using the MJS pile method.

[0008] As a preferred improvement, the vertex of the cement soil wall is taken as the origin, and the horizontal axis of the cement soil wall is Axis, the tangent line at the vertex of the cement soil wall is The axis constructs a plane rectangular coordinate system, and the parabola shape of the cement soil wall satisfies the parabola equation: , where , They represent the horizontal and vertical coordinates of a point on the cement soil wall in the plane rectangular coordinate system; Indicates the distance between the grouting hole and the vertex of the cement soil wall.

[0009] As a preferred improvement, the cement soil wall is symmetrically arranged about its own horizontal axis, and the distance between the two end points of the cement soil wall is 3D, where D represents the pile diameter of the bridge pile foundation.

[0010] As a preferred improvement, step S3 specifically includes the following steps: Step S31, taking the bridge pile foundation as the research object, based on the condition that saturated soil is incompressible, calculate the bridge pile foundation reset amount The volume of the void created in the soil of the offset side , the calculation process is expressed as: ; Step S32, taking the grouting slurry as the research object, based on the condition that the slurry is incompressible, calculate the volume of the slurry directly filled into the vacancy and the volume indirectly filled into the void after reflection from the cement soil wall , find the volume and volume The sum of is expressed as: ; In the formula, It indicates the distance between the bridge pile foundation and the grouting hole; Q indicates the amount of grouting slurry; Step S33, under the condition that the vacancy is completely filled with the grouting slurry, construct the equation , the expression of slurry volume Q is obtained by conversion, which is expressed as: ; Step S34, ignoring the energy consumed by the slurry movement, the grouting pressure All the work done is used to drive the bridge pile foundation to reset and build the reset force on the bridge pile foundation. Grouting pressure and the amount of bridge pile foundation reset The relationship between them is expressed as: ; Convert to: .

[0011] As a preferred improvement, the empirical formula for the resistance of the ground soil to the bridge pile foundation during the reset process is expressed as: ; In the formula, Indicates the weight of the soil in the stratum; Indicates the cohesion of the soil mass; It represents the internal friction angle of the soil mass; represents the intermediate calculation parameters, ; Indicates the depth of the soil layer.

[0012] As a preferred improvement, the numerical calculation method specifically includes the following steps: The bridge pile foundation is discretized into The calculation matrix of the pile deformation of the bridge pile foundation under load is as follows: ; In the formula, Indicates the displacement of the pile body; , denote the pile and soil stiffness matrices respectively; represents the pile node load matrix; in: ; In the formula, wiIndicates the displacement of each section of the pile; represents the transposed matrix; ; In the formula, represents the intermediate calculation parameters, ; represents the step length; ; In the formula, All represent intermediate calculation parameters; Indicates intermediate calculation parameters; ; ; In the formula, represents the foundation elastic parameters; represents the shear modulus of the soil layer; EI represents the bending stiffness of the bridge pile foundation; represents the elastic modulus of bridge pile foundation; represents the moment of inertia of the bridge pile foundation section; ; In the formula, Indicates i The restoring pressure on the pile foundation of the bridge section; Substitute the theoretical restoring force into the solution matrix to solve the pile node displacement under load. w i , the results w 0 is the displacement of the top of the bridge pile foundation.

[0013] As a preferred improvement, the deep grouting process in the grouting hole is as follows: The grouting starts from a depth of 20m. When the bottom pressure reaches the actual grouting pressure, the pressure is stabilized and the grouting pipe is slowly raised to 2m, and then lowered again, grouting with an up and down reciprocating motion to maintain pressure grouting.

[0014] The beneficial effects of the present invention are: (1) Deep grouting is used to generate restoring force to correct the deviation of bridge pile foundations, which can avoid the situation where traditional bridge pile foundations exert pressure on the ground, causing the pile body to be easily damaged due to excessive bending moment; (2) A parabolic cement-soil wall is set up on the side of the grouting hole away from the bridge pile foundation. The cement-soil wall provides a reaction force to ensure the size of the effective reset force and improve the grouting reset effect. The grouting hole is set at the focal position of the cement-soil wall, which can control the direction of the grouting reset force and ensure that the bridge pile foundation is reset in the predetermined direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 A schematic diagram showing the bridge pile foundation deviation correction and resetting solution provided by the present invention; Figure 2 Schematic diagram showing the locations of bridge pile foundations, grouting holes, cement soil walls and pressure relief holes; Figure 3 A schematic diagram showing a reaction force path of a parabolic cement soil wall provided by the present invention; Figure 4 A schematic diagram showing the reaction force path of a straight cement soil wall provided in the prior art; Figure 5 A schematic diagram showing the plane dimensions of the parabolic cement soil wall during the simulation process; Figure 6 A schematic diagram showing the plane dimensions of a straight cement soil wall during the simulation process; Figure 7 It shows the simulation results of parabolic cement soil wall; Figure 8 It shows the simulation results of the linear cement soil wall; Fig. 9 It represents the displacement curve of the pile body when the grouting pressure is assumed to be 750KPa; Fig.10 It represents the displacement curve of the pile body when the grouting pressure is assumed to be 650KPa. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] like Figure 1-Figure 10 As shown, this embodiment provides a method for correcting and resetting a bridge pile foundation, comprising the following steps: Step S1, selecting a bridge pile foundation correction and reset scheme: setting a grouting hole in the stratum soil on the deviated side, setting a cement soil wall in the stratum soil on the side of the grouting hole away from the bridge pile foundation, deep grouting in the grouting hole, and using the grouting pressure to drive the bridge pile foundation to reset; setting a pressure relief hole in the stratum soil on the reset side.

[0018] The bridge pile foundation 1, the grouting hole 2 and the cement soil wall 3 are all arranged in the stratum soil, and the grouting hole 2 and the cement soil wall 3 are located on the offset side of the bridge pile foundation 1, and the bridge pile foundation 1 and the cement soil wall 3 are located on opposite sides of the grouting hole 2. During the grouting process, the pressurized grouting liquid uniformly exerts an extrusion pressure on the surrounding stratum soil, and a part of the extrusion pressure is transmitted to the bridge pile foundation 1 through the stratum soil between the grouting hole 2 and the bridge pile foundation 1, and is directly used to drive the bridge pile foundation 1 to reset; the other part of the extrusion pressure is transmitted to the cement soil wall 3 through the stratum soil between the grouting hole 2 and the cement soil wall 3, and after the reaction force of the cement soil wall 3, it is transmitted to the bridge pile foundation 1 through the stratum soil between the cement soil wall 3 and the bridge pile foundation 1, and is indirectly used to drive the bridge pile foundation 1 to reset.

[0019] The setting of the cement soil wall 3 is used to reverse the force originally transmitted in the direction away from the bridge pile foundation 1 and transmit it in the direction close to the bridge pile foundation 1, which effectively reduces the dissipation of the grouting pressure and improves the utilization rate of the grouting pressure. The setting of the pressure relief hole 4 is used to reduce the soil pressure on the reset side to avoid the formation of excessive resistance. The number and location of the pressure relief hole 4 adopt conventional technology in this field, and this embodiment will not be described in detail.

[0020] It is understandable that in the technical solution of the present invention, the source of the restoring force of the bridge pile foundation 1 is the grouting pressure. Compared with the prior art method of directly applying the restoring force on the pile top, the present invention adopts the method of deep grouting to apply extrusion force to the stratum soil, and uses the stratum soil as a force transmission medium to evenly transmit the restoring force to each section of the pile body, so that the pile body can be reset synchronously, avoiding the generation of reverse curvature in the upper part of the bridge pile foundation 1. In addition, the grouting pressure also has the advantage of being controllable, and can be adjusted in real time according to the reset situation of the bridge pile foundation 1.

[0021] Step S2, determine the shape of the cement soil wall and the position of the grouting holes: the cement soil wall is parabolic, the arching direction is consistent with the deviation direction of the bridge pile foundation, the grouting holes and the bridge pile foundation are both located on the horizontal axis of the cement soil wall, and the grouting holes are located at the focal position of the cement soil wall.

[0022] The cement soil wall 3 plays a role of reaction force during the resetting process. Its shape directly affects the effect of the reaction force. In the prior art, the cement soil wall 3 is generally selected to be a straight line. By analyzing the reaction force process of the straight cement soil wall, it is found that: Figure 4 As shown, the grouting hole 2 can be regarded as a point structure, and the straight cement soil wall can be regarded as a linear structure. The force emitted from the grouting hole 2 is transmitted along the four sides in a radial shape. Only the force perpendicular to the straight cement soil wall and a small part of the force with a small incident angle can be transmitted toward the bridge pile foundation 1 after the reaction force of the straight cement soil wall, while most of the forces with a large incident angle deviate from the position of the bridge pile foundation 1 after the reaction force of the straight cement soil wall, and cannot be used to drive the bridge pile foundation 1 to reset. Figure 3 As shown, based on this, the present invention selects the cement soil wall 3 as a parabola, the grouting hole 2 and the bridge pile foundation 1 are both located on the horizontal axis of the cement soil wall 3, and the grouting hole 2 is located at the focal position of the cement soil wall 3. When the force emitted from the grouting hole 2 is transmitted in a radial manner along the four sides, most of the force can be transmitted in a direction and parallel to the bridge pile foundation 1 after the reaction force of the cement soil wall 3, which can reduce the dissipation of the grouting pressure and ensure the size of the effective reset force.

[0023] Specifically, the cement soil wall 3 is constructed using the MJS (Metro Jet System) pile construction method.

[0024] Taking the vertex of the cement soil wall as the origin, the horizontal axis of the cement soil wall is Axis, the tangent line at the vertex of the cement soil wall is The axis constructs a plane rectangular coordinate system, and the parabola shape of the cement soil wall satisfies the parabola equation: , where , They represent the horizontal and vertical coordinates of a point on the cement soil wall in the plane rectangular coordinate system; It represents the distance between the grouting hole and the vertex of the cement soil wall. The cement soil wall is symmetrically arranged about its own horizontal axis, and the distance between the two end points of the cement soil wall is 3D, where D represents the pile diameter of the bridge pile foundation.

[0025] From a structural point of view, the parabolic cement soil wall 3 is a semi-enclosed structure, and its opening direction is toward the grouting hole 2 and the bridge pile foundation 1, which can play a force gathering effect, reduce force dissipation, and enable forces in more directions to act on the bridge pile foundation 1, driving the bridge pile foundation 1 to reset; at the same time, due to the particularity of the focal position, the forces transmitted in different directions can be directed and parallel to the direction of the bridge pile foundation 1 after being reacted by the cement soil wall 3, ensuring the size of the effective reset force Furthermore, in order to prove the effectiveness of the parabolic cement soil wall provided by the present invention, it is compared with the linear cement soil wall in the prior art, and the reaction effects of the two are verified by simulation. During the simulation, the stratum soil in the target area is simulated using the Mohr-Coulomb model, and the length, width and depth of the stratum soil in the target area are set to be 40m, 40m and 60m, and the physical and mechanical parameter values ​​of each layer of the stratum soil are shown in Table 1.

[0026] Table 1 Physical and mechanical parameters of each layer of soil The cement-soil wall (linear cement-soil wall, parabolic cement-soil wall) and bridge pile foundation 1 are simulated using solid unit cells, and the contact surface with the stratum soil is established. The cement-soil wall and bridge pile foundation 1 are given elastic models. The unit density, elastic modulus and Poisson's ratio are taken according to reinforced concrete. The strength of the cement-soil wall is considered according to the strength of cement-soil. The structural parameters are shown in Table 2.

[0027] Table 2 Parameters of cement soil wall and bridge pile foundation structure The pressure relief hole 4 is simulated by weakening the soil parameters of the formation, and the weakening degree is selected as 10%. The depth of the grouting hole 2 is 15m, and the depth of the pressure relief hole 4 is 30m.

[0028] The plane dimensions of a straight cement soil wall are as follows: Figure 6 As shown, the plane dimensions of the parabolic cement soil wall are as follows Figure 5 During the simulation, except for the difference in the shape of the cement soil wall, the other parameters remain the same.

[0029] The simulation results are as follows Figure 7-Figure 8 As shown. Figure 7-Figure 8 It can be seen that, when other factors are the same, the parabolic cement-soil wall achieves a better reset amount than the linear cement-soil wall, indicating that the parabolic cement-soil wall 3 has a better reaction effect.

[0030] Step S3, using the energy variation principle to derive the relationship between the restoring force on the bridge pile foundation and the grouting pressure and the bridge pile foundation restoring amount.

[0031] Based on the incompressible condition of saturated soil, during the restoration process of the bridge pile foundation 1, the stratum soil on the restoration side is squeezed, causing the stratum soil on the restoration side to slide outward. At the same time, the bridge pile foundation 1 is separated from the stratum soil on the offset side, forming a gap. The void volume generated in the soil of the offset side It is expressed as: ; Where D represents the pile diameter of the bridge pile foundation 1; After grouting in the grouting hole 2, the grout squeezes the soil between the bridge pile foundation 1 and the grouting hole 2, filling it into the gap. Under ideal conditions without considering the loss of grout, the filling amount is equal to the grouting amount. Therefore, the gap between the bridge pile foundation 1 and the soil on the offset side can be understood as being completely filled by the total grouting amount Q in the grouting hole 2. Similar to the principle of force conduction direction in the previous text, there are also two ways to fill the total grouting amount Q: first, direct filling; second, indirect filling after reflection through the cement soil wall 3.

[0032] Taking the grouting slurry as the research object, represents the volume filled directly, represents the volume indirectly filled after reflection by the cement soil wall 3, and the total filled volume is expressed as: ; In the formula, It indicates the distance between the bridge pile foundation and the grouting hole; Q indicates the amount of grouting slurry; Since both the slurry and the formation soil are incompressible, therefore: ; Right now: ; Convert to: ; Ignoring the energy consumed by slurry movement, the grouting pressure All the work done is used to drive the bridge pile foundation 1 to reset, and build the reset force on the bridge pile foundation Grouting pressure and the amount of bridge pile foundation reset The relationship between them is expressed as: ; In the formula, Indicates the restoring force applied to the bridge pile foundation 1.

[0033] Convert to: .

[0034] Step S4, for any bridge pile foundation correction and resetting process, assume the grouting pressure value based on the resetting amount required for the bridge pile foundation, and calculate the theoretical resetting force generated by the grouting through the relationship provided in step S3; calculate the interaction force generated by the stratum soil and the bridge pile foundation during the resetting process based on the empirical formula, and use the interaction force value as the verification factor of the theoretical resetting force. If the theoretical resetting force value is greater than the verification factor, then take the interaction force value corresponding to the verification factor as the theoretical resetting force value; otherwise, retain the theoretical resetting force value.

[0035] The source document of this empirical formula is: Shen Zhujiang, "Sliding resistance of piles and limit design of anti-sliding piles", Chinese Journal of Geotechnical Engineering, 14(1), 1992: 51~56.

[0036] During the grouting process, the grouting body drives the soil to slide. When the bridge pile 1 exists in the sliding soil, the bridge pile 1 and the sliding soil generate an interaction force. The empirical formula gives the interaction force P p The expression of (z) is expressed as: ; In the formula, Indicates the weight of the soil in the stratum; Indicates the cohesion of the soil mass; It represents the internal friction angle of the soil mass; represents the intermediate calculation parameters, ; Indicates the depth of the soil layer.

[0037] The expression and empirical formula provided by the present invention characterize the magnitude of the restoring force exerted on the bridge pile foundation 1 from different perspectives. The present invention considers the force transmission situation with the grouting pressure as the research object; the empirical formula considers the force transmission situation with the action relationship between the pile bodies as the research object. Since the grouting pressure will dissipate to a certain extent during the transmission process through the stratum soil, the restoring force calculated by the expression provided by the present invention cannot be greater than the restoring force calculated by the empirical formula. Therefore, the interaction force value calculated by the empirical formula is used as a verification factor to evaluate the rationality of the expression provided by the present invention, which can ensure the effectiveness of the calculation.

[0038] Step S5, according to the determined theoretical reset force value, the pile body displacement is calculated by a numerical calculation method, and the top displacement of the bridge pile foundation is determined based on the calculated pile body displacement, and it is judged whether the error between the top displacement and the required reset amount is no more than 5%. If so, the assumed value of the grouting pressure is taken as the actual grouting pressure; otherwise, return to step S4 and re-assume the grouting pressure value for trial calculation until the error between the top displacement of the bridge pile foundation and the required reset amount is no more than 5%.

[0039] The numerical calculation method specifically includes the following steps: Discretize the bridge pile foundation 1 into The calculation matrix of the pile deformation of the bridge pile foundation 1 under load is as follows: ; In the formula, Indicates the displacement of the pile body; , denote the pile and soil stiffness matrices respectively; represents the pile node load matrix; in: ; In the formula, wi represents the displacement of each section of the pile body, i=1,2,3···n; represents the transposed matrix; ; In the formula, represents the intermediate calculation parameters, ; represents the step length; ; In the formula, All represent intermediate calculation parameters; Indicates intermediate calculation parameters; ; ; In the formula, represents the foundation elastic parameters; represents the shear modulus of the soil layer; EI represents the bending stiffness of the bridge pile foundation; represents the elastic modulus of bridge pile foundation; represents the moment of inertia of the bridge pile foundation section; ; In the formula, Indicates i The restoring pressure on the pile foundation of the bridge section; Substitute the theoretical restoring force into the solution matrix to solve the pile node displacement under load. w i , the results w 0 is the displacement of the top of the bridge pile foundation.

[0040] Calculate the error between the top displacement and the required reset amount : ; like , then the assumed grouting pressure For what is desired; otherwise, according to Results Adjustment ,when When On the contrary, increase appropriately .

[0041] Step S6, deep grouting is performed in the grouting hole with actual grouting pressure, and the bridge pile foundation is driven to reset by the grouting pressure.

[0042] In actual engineering applications, the grouting pressure is set to the actual grouting pressure, and the grouting hole 2 is used to continuously grout and monitor the reset amount until the pile top is corrected to a predetermined value.

[0043] Example 1 During the construction of a certain project, the bridge pile foundation 1 was deviated due to the side construction, and the top displacement of the bridge pile foundation 1 was 34 mm, which needed to be corrected. The bridge pile foundation correction and reset method provided by the present invention was used to guide the reset. The diameter of the bridge pile foundation 1 was 1.5 m, and the pile length was 69 m.

[0044] Through on-site survey, the soil strata in the area where the bridge pile foundation 1 is located are as follows from top to bottom: ① Miscellaneous fill layer, 2.0m thick, brownish yellow, grayish brown and other mixed colors, slightly wet, slightly compacted; ② Silt layer, 14.5m thick, dark grey, grey-black, plastic, mainly composed of clay, silt and organic matter, sticky and slippery, with sand in some parts, shell fragments, occasional rotten wood, and a slight fishy smell; ③ Muddy soil layer, 16.5m thick, dark grey, plastic, mainly composed of clay and silt, uniform, sticky, containing organic matter, partially containing sand, and occasionally rotten wood; ④ The lower overlying soil layer is composed of medium-coarse sand, gravel-sand layer and medium-weathered mixed granite. The bottom of the bridge pile foundation 1 is embedded in the medium-weathered mixed granite layer below 1.5m.

[0045] Cement soil wall 3 is laid on the offset side of bridge pile foundation 1. Cement soil wall 3 is constructed using MJS (Metro Jet System) pile construction method. The diameter of the cement soil pile is 1.5m, the spacing is 1.3m, and the pile length is 30m. The axis equation of cement soil wall 3 is: , a=2m, wall length 9m; the vertex is 8m away from the center of bridge pile foundation 1. Grouting hole 2 is drilled 6.0m away from the center of bridge pile foundation 1, and grouting is used to apply a reset force to help the offset pile reset.

[0046] The elastic modulus of bridge pile foundation 1 is E=3.1×107KPa, and the gravity is γ=19.5kN / m3; the comprehensive cohesion of the stratum soil is 10KPa, and the friction angle is 10°. The proposed reset amount s=34mm, according to the grouting pressure that can be achieved in the project, assuming pk=750KPa, the reset force is calculated according to the following formula : ; The calculation results are: =1114kN / m.

[0047] Calculate the interaction force according to the empirical formula P p (z): ; The calculation results show that Pp (z) increases with the depth of the soil layer z. When z=21m, Pp(z)=1157kN / m>1114kN / m, then keep =1114kN / m.

[0048] The bridge pile foundation 1 is discretized into 60 units with a length of 1m, and the pile displacement is calculated. The pile displacement results are as follows: Fig. 9 Shown: Among them w 0=48mm, the error with the intended reset amount s=34mm exceeds 5%, so it needs to be reduced Assumed value.

[0049] Adjust according to the gradient of 50KPa The value of is calculated several times. =650KPa, =965kN / m, the pile displacement results are as follows Fig.10 As shown, we get w 0=35mm, the error with the proposed reset amount s=34mm is less than 5%, so It is 650KPa.

[0050] The grouting slurry ratio (mass ratio) is: cement: water = 1:1. Grouting starts from a depth of 20m. When the bottom pressure reaches 650KPa, the pressure is stabilized and the grouting pipe is slowly raised to 2m, then lowered again, and the grouting is carried out in a reciprocating motion up and down to maintain pressure grouting. During the grouting process, the reset amount of the bridge pile foundation 1 is monitored until the grouting is stopped after it is completely reset. After the deviation of the bridge pile foundation 1 is corrected, the pressure relief hole 4 is backfilled and sealed with cement mortar.

[0051] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for correcting and resetting a bridge pile foundation, characterized in that: The steps include: Step S1, selecting a bridge pile foundation correction and reset scheme: setting a grouting hole in the stratum soil on the deviated side, setting a cement soil wall in the stratum soil on the side of the grouting hole away from the bridge pile foundation, deep grouting in the grouting hole, and using the grouting pressure to drive the bridge pile foundation to reset; setting a pressure relief hole in the stratum soil on the reset side; Step S2, determining the shape of the cement soil wall and the position of the grouting holes: the cement soil wall is parabolic, the arching direction is consistent with the deviation direction of the bridge pile foundation, the grouting holes and the bridge pile foundation are both located on the horizontal axis of the cement soil wall, and the grouting holes are located at the focal position of the cement soil wall; Step S3, using the energy variation principle to derive the relationship between the restoring force on the bridge pile foundation and the grouting pressure and the bridge pile foundation restoring amount; Step S4, for any bridge pile foundation deviation correction and resetting process, based on the required resetting amount of the bridge pile foundation, the grouting pressure value is assumed, and the theoretical resetting force generated by the grouting is calculated by the relationship provided in step S3; The interaction force between the stratum soil and the bridge pile foundation during the reset process is calculated based on the empirical formula, and the interaction force value is used as the verification factor of the theoretical reset force. If the theoretical reset force value is greater than the verification factor, the interaction force value corresponding to the verification factor is taken as the theoretical reset force value; Otherwise, the theoretical reset force value is retained; Step S5, according to the determined theoretical reset force value, the pile displacement is calculated by a numerical calculation method, and the top displacement of the bridge pile foundation is determined based on the calculated pile displacement, and it is judged whether the error between the top displacement and the required reset amount is not greater than 5%. If so, the assumed value of the grouting pressure is taken as the actual grouting pressure; otherwise, the process returns to step S4 and the grouting pressure value is re-assumed for trial calculation until the error between the top displacement of the bridge pile foundation and the required reset amount is not greater than 5%; Step S6, deep grouting is performed in the grouting hole with actual grouting pressure, and the bridge pile foundation is driven to reset by the grouting pressure.

2. The bridge pile foundation correction and resetting method according to claim 1 is characterized in that: The cement soil wall was constructed using the MJS pile method.

3. The bridge pile foundation correction and resetting method according to claim 1 is characterized in that: Taking the vertex of the cement soil wall as the origin, the horizontal axis of the cement soil wall is Axis, the tangent line at the vertex of the cement soil wall is The axis constructs a plane rectangular coordinate system, and the parabola shape of the cement soil wall satisfies the parabola equation: , where , They represent the horizontal and vertical coordinates of a point on the cement soil wall in the plane rectangular coordinate system; Indicates the distance between the grouting hole and the vertex of the cement soil wall.

4. The bridge pile foundation correction and resetting method according to claim 3 is characterized in that: The cement soil wall is set symmetrically about its own horizontal axis, and the distance between the two end points of the cement soil wall is 3D, where D represents the pile diameter of the bridge pile foundation.

5. The bridge pile foundation correction and resetting method according to claim 4 is characterized in that: Step S3 specifically includes the following steps: Step S31, taking the bridge pile foundation as the research object, based on the condition that saturated soil is incompressible, calculate the bridge pile foundation reset amount The volume of the void created in the soil of the offset side , the calculation process is expressed as: ； Step S32, taking the grouting slurry as the research object, based on the condition that the slurry is incompressible, calculate the volume of the slurry directly filled into the vacancy and the volume indirectly filled into the void after reflection from the cement soil wall , find the volume and volume The sum of is expressed as: ； In the formula, It indicates the distance between the bridge pile foundation and the grouting hole; Q indicates the amount of grouting slurry; Step S33, under the condition that the vacancy is completely filled with the grouting slurry, construct the equation , the expression of slurry volume Q is obtained by conversion, which is expressed as: ； Step S34, ignoring the energy consumed by the slurry movement, the grouting pressure All the work done is used to drive the bridge pile foundation to reset and build the reset force on the bridge pile foundation. Grouting pressure and the amount of bridge pile foundation reset The relationship between them is expressed as: ； Convert to: 。 6. The bridge pile foundation deviation correction and resetting method according to claim 1 is characterized in that: The empirical formula for the resistance of the ground soil to the bridge pile foundation during the reset process is: In the formula, Indicates the weight of the soil in the stratum; Indicates the cohesion of the soil layer; It represents the internal friction angle of the soil mass; represents the intermediate calculation parameters, ; Indicates the depth of the soil layer.

7. The bridge pile foundation deviation correction and resetting method according to claim 1 is characterized in that: The numerical calculation method specifically includes the following steps: The bridge pile foundation is discretized into The calculation matrix of the pile deformation of the bridge pile foundation under load is as follows: ； In the formula, Indicates the displacement of the pile body; , denote the pile and soil stiffness matrices respectively; represents the pile node load matrix; in: ; In the formula, wi Indicates the displacement of each section of the pile; represents the transposed matrix; ； In the formula, represents the intermediate calculation parameters, ; represents the step length; ； In the formula, All represent intermediate calculation parameters; Indicates intermediate calculation parameters; ； ； In the formula, represents the foundation elastic parameters; represents the shear modulus of the soil layer; EI represents the bending stiffness of the bridge pile foundation; represents the elastic modulus of bridge pile foundation; represents the moment of inertia of the bridge pile foundation section; ； In the formula, Indicates i The restoring pressure on the pile foundation of the bridge section; Substitute the theoretical restoring force into the solution matrix to solve the pile node displacement under load. w i , the results w 0 is the displacement of the top of the bridge pile foundation.

8. The bridge pile foundation deviation correction and resetting method according to claim 1 is characterized in that: The deep grouting process in the grouting hole is as follows: grouting starts from a depth of 20m. When the bottom pressure reaches the actual grouting pressure, the pressure is stabilized and the grouting pipe is slowly raised to 2m, and then lowered again, and the grouting is performed by reciprocating up and down to maintain the pressure grouting.

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