A bridge ultra-deep foundation reinforcement structure and construction method thereof

Abstract

The present application discloses a super-deep foundation reinforcement structure for a bridge and a construction method thereof, comprising a wall reinforcement area and a central reinforcement area arranged inside the wall reinforcement area, wherein the central reinforcement area comprises a first reinforcement area and / or a second reinforcement area, wherein the first reinforcement area comprises a plurality of first reinforcement bodies arranged in an array, and two adjacent first reinforcement bodies are arranged tangentially; the second reinforcement area comprises a plurality of second reinforcement bodies arranged in an array, and two adjacent second reinforcement bodies are partially overlapped; each first reinforcement body is reinforced and formed once, and each second reinforcement body is reinforced and formed once; when the central reinforcement area comprises the first reinforcement area and the second reinforcement area, the first reinforcement area and the second reinforcement area are stacked, the first reinforcement area is arranged on the upper layer of the second reinforcement area, the axes of the first reinforcement body and the second reinforcement body at the corresponding position coincide, and the first reinforcement body and the second reinforcement body are coaxially constructed and reinforced and formed once.

Description

Technical Field

[0001] The present application generally relates to the field of construction engineering technology, and specifically to an ultra-deep foundation reinforcement structure for a bridge and a construction method thereof. Background Art

[0002] The anchor is located on an island in the middle of the alluvial river. The bedrock of the project site is buried more than 100m deep, and the thickness of the weak cover layer is more than 50m. It is mainly composed of silty clay, with low strength and foundation friction coefficient, poor plasticity, high compressibility, and no bearing layer that meets the requirements of traditional ground-anchored walls. The sand layers near the bottom of the foundation pit are highly permeable and pressurized aquifers. The head of the pressurized water is high, and there is no natural waterproof layer at the base. During the construction of the foundation pit, the anchor foundation serves as the main anchoring function of the foundation pit, and its bottom has high anti-slip requirements. However, the bottom of the foundation pit during the construction period in the existing technology is not only high-risk, but basically impossible to construct. How to solve the problems of waterproofing, bearing capacity and anti-slip at the bottom of the pit during the construction process is the key. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide an ultra-deep foundation reinforcement structure for a bridge and a construction method thereof, which can improve the strength, friction and impermeability of the bridge foundation reinforcement structure.

[0004] In a first aspect, the present application provides a bridge foundation reinforcement structure, comprising a wall reinforcement area and a central reinforcement area arranged inside the wall reinforcement area, wherein the central reinforcement area comprises a first reinforcement area and / or a second reinforcement area, wherein the first reinforcement area comprises a plurality of first reinforcement bodies arranged in an array, and two adjacent first reinforcement bodies are arranged tangentially; the second reinforcement area comprises a plurality of second reinforcement bodies arranged in an array, and two adjacent second reinforcement bodies partially overlap; each of the first reinforcement bodies is reinforced and formed at one time, and each of the second reinforcement bodies is reinforced and formed at one time;

[0005] When the central reinforcement area includes the first reinforcement area and the second reinforcement area, the first reinforcement area and the second reinforcement area are stacked, the first reinforcement area is arranged on the upper layer of the second reinforcement area, the axis of the first reinforcement body and the second reinforcement body at the corresponding position coincide, and the first reinforcement body and the second reinforcement body are coaxially constructed and reinforced in one step.

[0006] Optionally, the wall reinforcement area includes a first edge reinforcement body arranged on the same layer as the first reinforcement body and a second edge reinforcement body arranged on the same layer as the second reinforcement body, and there is a partial overlap between two adjacent second edge reinforcement bodies; the axis of the first edge reinforcement body and the second edge reinforcement body at the corresponding position coincide.

[0007] Optionally, the height of the first reinforcement body is greater than the height of the second reinforcement body, the diameter of the first reinforcement body is smaller than the diameter of the second reinforcement body, the diameters of the first edge reinforcement body and the first reinforcement body are the same, and the diameters of the second edge reinforcement body and the second reinforcement body are the same; the center distance between two adjacent first edge reinforcement bodies is smaller than the center distance between two adjacent first reinforcement bodies, and the center distance between two adjacent second edge reinforcement bodies is smaller than the center distance between two adjacent second reinforcement bodies.

[0008] Optionally, the first reinforcement body has a height of 20m to 27m and a diameter of 1.5m to 2m;

[0009] The second reinforcement body has a height of 4m to 8m and a diameter of 2.4m to 3m;

[0010] The bottom depth of the first reinforcement body is 40m to 51m;

[0011] The bottom depth of the second reinforcement body is 48m to 55m.

[0012] In a second aspect, the present application provides a construction method for a bridge foundation reinforcement structure, which is used to form a bridge foundation reinforcement structure as described above, and is constructed using a jet grouting drill rod, wherein the jet grouting drill rod includes a first nozzle and a second nozzle arranged up and down, wherein the first nozzle is used to spray high-pressure water and high-pressure air, and the second nozzle is used to spray high-pressure hardening material; the method includes:

[0013] forming a lead hole at an axial position of the first reinforcement body and / or the second reinforcement body;

[0014] A plurality of first reinforcement bodies and / or a plurality of second reinforcement bodies arranged in an array are formed by extending a jet-jet drill rod into the guide hole and jet-jet hardening the plurality of first reinforcement bodies and / or a plurality of second reinforcement bodies;

[0015] When the central reinforcement area includes the first reinforcement area and the second reinforcement area, the first reinforcement body and the second reinforcement body are reinforced and formed at one time by extending the same jet grouting drill rod into the same guide hole for coaxial construction through jet grouting hardening;

[0016] The method of the rotary spray hardening specifically includes:

[0017] The soil is pre-cut by rotating and spraying high-pressure water and high-pressure air through the first nozzle to expand the pile body and form a cement slurry of water and native soil;

[0018] The soil is cut for a second time by rotating and spraying the high-pressure hardening material through the second nozzle to expand the pile body again and form a reinforced body slurry of the hardening material and cement slurry.

[0019] Optionally, before forming the lead hole, the method further includes:

[0020] A steel casing of a certain depth is buried on the site corresponding to each of the lead hole positions, and a collection pit for collecting the cement slurry and the reinforcement slurry is opened at each of the lead hole positions.

[0021] Optionally, the diameter of the lead hole is 40 cm to 65 cm; the diameter of the jet grouting drill rod is 10 cm to 20 cm; the spacing between the lead hole and the jet grouting drill rod to form a return slurry channel is 15 cm to 20 cm;

[0022] The method for forming the lead hole comprises:

[0023] Drilling is done by using a drill bit with the aid of mud wall protection;

[0024] The verticality measurement is performed once at every fixed height to ensure that the verticality deviation of the lead hole is ≤1 / 300.

[0025] Optionally, the first nozzle is close to the upper surface of the foundation, the second nozzle is far from the upper surface of the foundation, the first nozzle and the second nozzle are arranged on opposite sides of the rotary jet drilling rod, and the diameter of the pile body formed by pre-cutting by the first nozzle is smaller than the diameter of the pile body formed by secondary cutting by the second nozzle;

[0026] The operation method of the rotary grouting hardening includes: the rotary grouting drill rod is lifted while rotating and spraying, from the bottom of the guide hole upward, and after the first nozzle rotates and sprays to a certain height, the second nozzle is opened for selective spraying.

[0027] Optionally, the distance between the first nozzle and the second nozzle on the jet jet drill rod is 1.2m to 1.4m;

[0028] When forming the second reinforcement body, the pressure of the high-pressure water of the first nozzle is 35MPa-45MPa, and the flow rate is 180L / min-220L / min; the pressure of the high-pressure air is 1.05MPa-1.75MPa, and the flow rate is 5.0Nm 3 / min~6.5Nm 3 / min; the pressure of the high-pressure hardening material of the second nozzle is 40MPa-45MPa, and the flow rate is 120L / min-155L / min; the spray radius of the first nozzle is 85%-90% of the radius of the second reinforcement body; the spray radius of the second nozzle is 10%-15% of the radius of the second reinforcement body;

[0029] When forming the first reinforcement body, the pressure of the high-pressure water of the first nozzle is 25MPa-37MPa, and the flow rate is 150L / min-200L / min; the pressure of the high-pressure air is 0.75MPa-1.25MPa, and the flow rate is 4.5Nm3 / min~5.5Nm 3 / min; the pressure of the high-pressure hardening material of the second nozzle is 37MPa~42MPa; the spraying radius of the first nozzle is 85%~90% of the radius of the first reinforced body; the spraying radius of the second nozzle is 10%~15% of the radius of the first reinforced body.

[0030] Optionally, the first reinforcement body and the second reinforcement body at corresponding positions are formed by two jet grouting hardening processes through the same jet grouting drill rod;

[0031] The method further comprises:

[0032] In addition to the rotary grouting rod and the rotary grouting drill rod, after the reinforcement slurry is initially set, grouting is injected again into the lead hole to form a secondary filling.

[0033] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0034] The ultra-deep foundation reinforcement structure for bridges provided in the embodiment of the present application is suitable for ultra-deep foundations of bridges. The purpose of foundation reinforcement can be achieved by setting up a double-layer reinforcement body, forming an "artificial waterproof layer" with ultra-high reinforcement strength, a friction coefficient that meets the requirements and a small permeability coefficient, thereby meeting the needs of the anchored ground-connected wall foundation for a bearing layer, a friction layer and a water-sealing layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0036] Figure 1 A structural schematic diagram of a reinforcement structure provided in an embodiment of the present application;

[0037] Figure 2 A schematic cross-sectional view of a reinforcement structure provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the arrangement of a reinforcement structure provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of the arrangement of a first reinforcement area provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the arrangement of a second reinforcement area provided in an embodiment of the present application;

[0041] Figure 6 A structural schematic diagram of a reinforcement structure construction location provided in an embodiment of the present application;

[0042] Figure 7-10 A schematic diagram of a construction method of rotary grouting hardening provided in an embodiment of the present application;

[0043] Fig.11 A schematic diagram of soil between piles at a hole location provided in an embodiment of the present application;

[0044] Fig.12 A schematic diagram of slurry discharge of a rotary jet drilling rod provided in an embodiment of the present application;

[0045] Fig.13 A schematic diagram of slurry discharge for a rotary jet drill rod provided in an embodiment of the present application.

[0046] In the figure,

[0047] 100, wall reinforcement area; 200, center reinforcement area; 300, ground-connected wall bottom; 400, outer wall;

[0048] 110, first reinforcing body; 120, second reinforcing body; 130, first edge reinforcing body; 140, second edge reinforcing body;

[0049] D1, first reinforcement area; D2, second reinforcement area; I, first deep area; II, second deep area; III, third deep area;

[0050] 10. Jet jet drill rod; 11. First nozzle; 12. Second nozzle;

[0051] 20. Lead hole; 21. Invalid lead hole; 30. Pre-formed hole;

[0052] 40. Collection pit; 50. Mud discharge equipment;

[0053] 1. High-pressure water; 2. High-pressure air; 3. Hardened material; 4. Cement slurry; 5. Added solid slurry. DETAILED DESCRIPTION

[0054] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0055] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] Please see Figure 1-2The present application provides a bridge foundation reinforcement structure, including a wall reinforcement area 100 and a central reinforcement area 200 arranged inside the wall reinforcement area 100, wherein the central reinforcement area 200 includes a first reinforcement area D1 and / or a second reinforcement area D2 arranged in a stacked manner, wherein the first reinforcement area D1 includes a plurality of first reinforcement bodies 110 arranged in an array, and two adjacent first reinforcement bodies 110 are arranged tangentially; and the second reinforcement area D2 includes a plurality of second reinforcement bodies 120 arranged in an array, and two adjacent second reinforcement bodies 120 partially overlap;

[0057] Each of the first reinforcement bodies 110 is reinforced and formed at one time, and each of the second reinforcement bodies 120 is reinforced and formed at one time; when the central reinforcement area 200 includes the first reinforcement area D1 and the second reinforcement area D2, the first reinforcement area D1 and the second reinforcement area D2 are stacked, the first reinforcement area D1 is arranged on the upper layer of the second reinforcement area D2, the axis of the first reinforcement body 110 and the second reinforcement body 120 at the corresponding position coincide, and the first reinforcement body 110 and the second reinforcement body 120 are coaxially constructed and reinforced and formed at one time.

[0058] The ultra-deep foundation reinforcement structure for bridges provided in the embodiments of the present application is suitable for ultra-deep foundations of bridges. The purpose of foundation reinforcement can be achieved by setting up a double-layer reinforcement body, thereby forming an "artificial waterproof layer" with ultra-high reinforcement strength, a friction coefficient that meets the requirements and a small permeability coefficient, thereby meeting the needs of the anchored ground-connected wall foundation for the bearing layer, friction layer and water-sealing layer.

[0059] Understandably, Figure 1 FIG. 1 shows a schematic diagram of the structure of a portion of the central reinforcement area in the reinforcement structure, wherein a portion of the first reinforcement body 110 is removed from the first reinforcement body layer D1. Figure 2 The individual structures of the first reinforcement body 110 and the second reinforcement body 120 are not shown. Figure 3 The figure shows an arrangement of various reinforcement bodies in a reinforcement structure, wherein the upper semicircle is a schematic diagram of the arrangement of the first reinforcement body 110 on the first reinforcement layer D1 and the first edge reinforcement body 130 on the wall reinforcement area 100 on the same layer as the first reinforcement layer D1; the lower semicircle is a schematic diagram of the arrangement of the second reinforcement body 120 on the second reinforcement layer D2 and the second edge reinforcement body 140 on the wall reinforcement area 100 on the same layer as the second reinforcement layer D2.

[0060] In this embodiment, the wall reinforcement area 100 includes a first edge reinforcement body 130 arranged at the same layer as the first reinforcement body 110 and a second edge reinforcement body 140 arranged at the same layer as the second reinforcement body 120, and there is a partial overlap between two adjacent second edge reinforcement bodies 140; the axis of the first edge reinforcement body 130 and the second edge reinforcement body 140 at the corresponding position coincide.

[0061] In the embodiment of the present application, an outer wall 400 can be set on the periphery of the reinforcement structure. The outer wall 400 is a continuous structure. The central reinforcement area 200 is set in the central area of ​​the outer wall 400. The wall reinforcement area is set in the area around the central reinforcement area 200 close to the wall reinforcement area. The wall reinforcement area can form an outer layer with dense waterproofing and reinforcement effects. In the present application, the first edge reinforcement body 130 on the wall reinforcement area 100 partially overlaps with the first reinforcement body 110, and the second edge reinforcement body 140 partially overlaps with the second reinforcement body 120. At the same time, the first edge reinforcement body 130 and the second edge reinforcement body 140 both partially overlap with the outer wall 400, which can improve the connection strength of the reinforcement structure and improve the edge permeability coefficient.

[0062] During arrangement, the height of the first reinforcement body 110 is greater than the height of the second reinforcement body 120, the diameter of the first reinforcement body 110 is smaller than the diameter of the second reinforcement body 120, the diameter of the first edge reinforcement body 130 is the same as the first reinforcement body 110, and the diameter of the second edge reinforcement body 140 is the same as the second reinforcement body 120; the center distance between two adjacent first edge reinforcement bodies 130 is smaller than the center distance between two adjacent first reinforcement bodies 110, and the center distance between two adjacent second edge reinforcement bodies 140 is smaller than the center distance between two adjacent second reinforcement bodies 120.

[0063] In one embodiment of the present application, Figure 3 As shown, the central reinforcement area 200 includes a first deep area I, a second deep area II, and a third deep area III which are arranged in succession. The height of the first deep area I is less than the height of the third deep area III. The height of the first reinforcement body 110 in the first deep area I is less than the height of the first reinforcement body 110 in the third deep area III. The height of the second reinforcement body 120 in the first deep area I is equal to the height of the second reinforcement body 120. The height of the first reinforcement body 110 in the second deep area II is equal to the height of the first reinforcement body 110 in the first deep area I. The height of the second reinforcement body 120 in the second deep area II is equal to the height of the second reinforcement body 120 in the third deep area III.

[0064] It is understandable that when the reinforcement structure provided by the present application is applied to a bridge structure, different stress conditions may exist at different positions of the same reinforcement structure according to different application positions. The present application illustrates that the bearing capacity of the first deep zone I is less than that of the third deep zone III. In the present application, the height of the first reinforcement body 110 can be increased to increase the bearing capacity of the reinforcement structure within the third deep zone III, thereby saving costs. In addition, in order to improve the transition capacity between the first deep zone I and the third deep zone III and prevent problems such as stress concentration, a transitional second deep zone II is set between the first deep zone I and the third deep zone III in the present application. By increasing the height of the second reinforcement body 120 within the second deep zone II, the bearing capacity of the transition zone is increased, the stress of the first deep zone I and the second deep zone II is balanced, and the life of the reinforcement structure is increased.

[0065] In the embodiment of the present application, the height of the first reinforcement body 110 is 20m to 27m and the diameter is 1.5m to 2m;

[0066] The second reinforcement body 120 has a height of 4m to 8m and a diameter of 2.4m to 3m;

[0067] The bottom depth of the first reinforcement body 110 is 40m to 51m;

[0068] The bottom depth of the second reinforcement body 120 is 48 m to 55 m.

[0069] It is understandable that the cross-sectional shape of the reinforcement structure after the multiple reinforcement bodies are formed is not limited in the embodiment of the present application, and can be a regular shape such as a circle, a square, a triangle, an edgeless shape, or other irregular shapes, which can be set according to the scene, etc. in specific applications. The embodiment of the present application is described by way of example with a circular cross section.

[0070] like Figure 4 and Figure 5 The arrangement of some reinforcement bodies is shown in the figure. The solid line in the figure is the first reinforcement body 110 or the second reinforcement body 120, and the dotted line is the first edge reinforcement body 130 or the second edge reinforcement body 140. In each layer, the wall reinforcement area 100 includes 162 piles evenly arranged along the inner edge line of the ground wall, and the pile center distance is 1.673m; the central reinforcement area 200 is the area other than the wall reinforcement area 100, and the pile center distance is 1.7m. The center distance between the first edge reinforcement body 130 and the first reinforcement body 110 is 2.1m.

[0071] In the first reinforcement area D1 of the upper layer in the present application, the pile diameter of the first reinforcement body 110 is 1.7m; in the second reinforcement area D2 of the lower layer, the pile diameter of the second reinforcement body 120 is 2.4m, and the overlap (overlap size) is 0.7m. The arrangement of the first reinforcement area D1 and the second reinforcement area D2 is shown in Table 1 below.

[0072] Table 1

[0073]

[0074] As can be seen from the above table, the reinforcement structure in this application is suitable for ultra-deep foundations with a foundation depth of more than 50m. However, the existing methods cannot achieve the formation of a second reinforcement body 120 with a diameter of more than 2.4m at an ultra-deep height of 50m. Generally, if the reinforcement is too deep, the pressure in the ground will be too large. When using the rotation hardening method, it will offset part of the energy of the ultra-high pressure hardening material and the air jet fluid or the ultra-high pressure water 1 and the air jet fluid, making the pile diameter smaller. At the same time, because the reinforcement is too deep, the effect of air lift is not very good, resulting in unsmooth slurry return, which further increases the pressure in the ground. At the same time, it is easy to collapse the hole during reinforcement, which will lock the drill rod, thereby increasing the construction risk and difficulty. The formation method of the reinforcement structure in the prior art has a theoretical pile diameter of 3m within 20m, and the pile diameter decreases by 20cm for every 10m of depth thereafter. According to actual tests, it is difficult to reach a pile diameter of 2.4m at a depth of 50m.

[0075] Based on this ultra-deep height foundation, the present application also provides a construction method for a bridge foundation reinforcement structure, which is used to form a bridge foundation reinforcement structure as described above, using Figure 6 The method is constructed by using a rotary jet drill rod 10, the rotary jet drill rod 10 includes a first nozzle 11 and a second nozzle 12 arranged up and down, the first nozzle 11 is used to spray high-pressure water 1 and high-pressure air 2, and the second nozzle 12 is used to spray high-pressure hardening material 3; the method includes:

[0076] S100, forming a guide hole 20 at an axial position of the first reinforcement body 110 and / or the second reinforcement body 120;

[0077] When the central reinforcement area 200 includes the second reinforcement body 120, the method includes: S200, extending the jet grouting drill rod 10 into the guide hole 20 to form a plurality of second reinforcement bodies 120 arranged in an array by jet grouting hardening;

[0078] When the central reinforcement area 200 includes the second reinforcement body 120, the method includes: S300, extending the jet grouting drill rod 10 into the guide hole 20 to form a plurality of first reinforcement bodies 110 arranged in an array by jet grouting hardening;

[0079] When the central reinforcement area 200 includes the first reinforcement area D1 and the second reinforcement area D2, the same jet grouting drill rod 10 is extended into the same guide hole 20 for coaxial construction, and the first reinforcement body 110 and the second reinforcement body 120 are reinforced and formed at one time by jet grouting hardening.

[0080] Among them, Figure 7-10As shown, the method of rotary spray hardening specifically includes:

[0081] ST02, pre-cutting the soil by rotating and spraying high-pressure water and high-pressure air through the first nozzle 11 to expand the pile body and form a cement slurry 4 of water and native soil;

[0082] ST04, the soil is cut for the second time by rotating and spraying the high-pressure hardening material 3 through the second nozzle 12 to expand the pile body again and form a reinforced solid slurry 5 of the hardening material 3 and cement slurry 4.

[0083] In the construction method provided by the present application, the original soil concrete formed by cutting by the ultra-high pressure air 2 and ultra-high pressure water 1 sprayed by the first nozzle 11 in the upper section is discharged through the slurry return channel under the action of the high pressure air 2 and the injected water. At the same time, the ultra-high pressure hardening material 3 sprayed by the second nozzle 12 in the lower section forms secondary cutting and forms reinforced solid slurry 5, which is also conducive to the discharge of the original soil cement slurry, thereby reducing the internal pressure of the ground, effectively retaining the secondary cutting energy of the lower section, and forming a pile body with a larger diameter.

[0084] The construction method provided by the present application is that the upper section sprays ultra-high pressure water 1 and ultra-high pressure air 2 and the lower section sprays high pressure hardening material 3. Under the action of pressure, the internal slurry is subjected to forces in opposite directions. The spray force provided by the second nozzle 12 in the lower section will carry the waste cement slurry 4 upward to discharge it, and the spray force provided by the first nozzle 11 in the upper section will press the ultra-high pressure hardening material 3 slurry in the lower section tightly against the lower side of the lead hole 20 to fill it, so that only a small part of the ultra-high pressure hardening material 3 slurry is taken out.

[0085] It is understandable that the high-pressure hardening material 3 sprayed by the second nozzle 12 in the embodiment of the present application does not contain high-pressure air 2, so as to prevent the ultra-high-pressure hardening material 3 slurry from being guided upward and carrying out a large part of the reinforcement slurry under the action of gas lift. If the second nozzle 12 contains high-pressure air 2 during the spraying process, the reinforcement hardening material 3 is about 20% of the reinforcement body through the return slurry during the spraying process, that is, 20% of the hardening material 3 is wasted. The method of spraying the high-pressure hardening material 3 by the second nozzle 12 in the present application can improve the replacement rate of the ultra-high-pressure hardening material.

[0086] The construction method provided by the present application reasonably improves the replacement rate of the reinforcement hardening material 3, reduces the consumption of reinforcement hardening raw materials, saves the investment of hardening raw materials, and reduces the investment of project costs, while ensuring the strength, friction coefficient, and permeability coefficient of the upper and lower composite reinforced soil. The same reinforcement effect can be achieved by injecting less raw materials. At the same time, the use of large-diameter lead holes 20 can improve the verticality of the reinforcement body and ensure the bite effect. At the same time, a reliable return slurry channel can be established to reduce the pressure in the ground, creating good conditions for ultra-high pressure hardening materials and air jet fluids, thereby ensuring the diameter and quality of the reinforcement body.

[0087] It should be noted that the formation order of the first reinforcement body 110 and the second reinforcement body 120 at the corresponding position is not limited in the embodiments of the present application. In some embodiments, the first reinforcement body 110 and the second reinforcement body 120 can be formed simultaneously based on the same lead hole 20. For example, the second spin spraying process is used on the corresponding second reinforcement layer, and after it is lifted to a certain height, the first spin spraying process is used to continue to form the first reinforcement body 110. In other embodiments, each second reinforcement body 120 can be formed on the second reinforcement area D2 first, and after the second reinforcement body 120 is hardened and formed, each first reinforcement body 110 is formed on the first reinforcement body 110 area. In the present application, since the reinforcement structure provided can be formed in a variety of ways, it is selected according to the scene or cost in the specific application, and the present application does not limit it.

[0088] In the embodiment of the present application, the diameter of the lead hole 20 is 40cm to 65cm; the diameter of the jet grouting drill rod 10 is 10cm to 20cm; the spacing between the lead hole 20 and the jet grouting drill rod 10 to form the return grouting channel is 15cm to 20cm. For example, the diameter of the jet grouting drill rod 10 is 11cm, the diameter of the lead hole 20 is between 40cm and 65cm, and the radius difference on both sides is 15 to 20cm, that is, the space of the return grouting channel is a circular ring of 15 to 20cm.

[0089] An important improvement in the construction method provided in the present application lies in the setting of the guide hole 20 and the setting of the diameter of the guide hole 20. The setting of the guide hole 20 in the present application is conducive to establishing a reliable return slurry channel, reducing the pressure inside the reinforcement area, and reducing the energy loss of jet cutting.

[0090] The larger the diameter of the lead hole 20, the farther the upper high-pressure air 2 and high-pressure water 1 have to travel to cut the soil when cutting the pile body, but the suspension will also lose part of the energy ejected. When the lead hole 20 reaches a certain diameter, the energy is completely lost and the surrounding soil cannot be cut. The larger the lead hole 20, the greater the risk of hole collapse; the larger the lead hole 20, the longer the construction time, which means that the specifications of the lead hole 20 equipment will also be larger, and the price of the lead hole 20 equipment will increase exponentially.

[0091] The most important thing is that Fig.11As shown, since the second reinforcement bodies 120 are overlapped (interlocked) one by one, if the lead hole 20 (area A) is too large, it will damage the reinforcement bodies that have been piled around. At the same time, the larger the lead hole 20, the smaller the area of ​​the soil between the piles (area B), and the soil between the piles may collapse, resulting in hole collapse, stuck drill rods, and safety accidents. In addition, if the lead hole 20 is the same size as the reinforced pile, concrete can actually be directly poured to form a concrete structure, and the cost will increase geometrically; more importantly, in the embodiment of the present application, the second reinforcement body 120 in the second reinforcement layer is arranged in an overlapping manner. If the lead hole 20 is too large, the overlapping second reinforcement body 120 cannot be formed, and the full-section sealing requirement cannot be formed. If the diameter of the lead hole 20 is too small, the underground internal pressure is too large, causing part of the jet energy of the upper cutting soil to counteract the internal pressure of the ground, and the remaining part will cut the soil, resulting in the diameter of the upper pre-formed hole 30 being too small. Therefore, under the same construction parameters, the pile diameter is small.

[0092] In the embodiment of the present application, the axes of the first reinforcement body 110 and the second reinforcement body 120 coincide, and the same lead hole 20 is used to realize the rotation hardening of the second reinforcement body 120 and the upper first reinforcement body 110. In step S100, the method of forming the lead hole 20 includes:

[0093] Drilling is done by using a drill bit with the aid of mud wall protection;

[0094] The verticality measurement is performed once at a fixed height interval to ensure that the verticality deviation of the lead hole 20 is ≤1 / 300.

[0095] For example, to meet the requirements of the second reinforcement body 120 with a pile diameter of 2.4 m, a pile spacing of 1.7 m, a bite of 70 cm, and an allowable deviation of only 22 cm, in order to improve the water-stopping ability and the bearing capacity, the verticality deviation is required to be less than 1 / 220.

[0096] During construction, a 60cm drill bit is used to drill the pre-formed hole 30, and the verticality is measured every 10m. If there is a deviation, it is corrected and adjusted in time until the lead hole 20 is 1.4m deeper than the designed pile body of the reinforcement body. It can be understood that the depth of the lead hole 20 of 1.4m requires the spacing between the first nozzle 11 and the second nozzle 12 to be reserved so that the first nozzle 11 of the jet grouting drill rod 10 can perform jet grouting at the preset position. The lead hole 20 below the second reinforcement body 120 is described as an invalid lead hole 21.

[0097] The verticality of the lead hole 20 is directly related to the accurate position of the reinforced pile. This method uses a large diameter lead hole 20 of 40 cm to 65 cm, which reserves space for adjusting the position during the process of the ultra-high pressure jet grouting drill rig, allowing the drill rod to sag naturally under the action of gravity, so that the verticality of the ultra-high pressure jet grouting drill rod 10 in the later stage is no longer affected by the pre-formed hole 30. It can be understood that the diameter of the lead hole 20 can be adjusted and optimized according to the height of the reinforced body, and the specific adjustment size is mainly to facilitate the establishment of a reliable grouting channel and reserve adjustment space.

[0098] The present application adopts a rotary spray hardening method in steps S200 and S300, using high-pressure equipment to make high-pressure water and high-pressure air become high-pressure jets, which are ejected from nozzles to impact and destroy the soil, thereby cutting the soil. In addition, the rotary spraying method can also achieve a stirring function to form a cement slurry, in which some fine soil materials emerge from the water with the cement slurry, and the remaining soil particles are stirred and mixed with the slurry under the impact force of the jet flow, centrifugal force and gravity, and are regularly rearranged according to a certain slurry-soil ratio.

[0099] Among them, the first nozzle 11 is close to the upper surface of the foundation, and the second nozzle 12 is far away from the upper surface of the foundation. The first nozzle 11 and the second nozzle 12 are arranged on opposite sides of the rotary jet drill rod 10. The diameter of the pile body cut by the first nozzle 11 is smaller than the diameter of the pile body formed by the secondary cutting of the second nozzle 12, that is, the diameter of the pre-formed hole 30 formed by the first nozzle 11 is smaller than the diameter of the first reinforcement body 110.

[0100] Wherein, the operation mode of the rotary spray hardening includes: Figure 7-10 As shown, the jet grouting drill rod 10 is lifted while rotating and jetting, from the bottom of the guide hole 20 upwards, and after the first nozzle 11 rotates and jets to a certain height, the second nozzle 12 is opened for selective jetting.

[0101] It should be noted that, in the embodiment of the present application, the high-pressure air 2 and the high-pressure water 1 in the first nozzle 11 adopt a setting mode of high-pressure air 2 enclosing high-pressure water 1, that is, the high-pressure air 2 is located at the periphery of the injection range and the high-pressure water 1 is located at the center of the injection range of the high-pressure air 2, forming high-pressure water and high-pressure air similar to "air-enclosed water", which can achieve cutting and stirring effects through the air-enclosed water method.

[0102] The first nozzle 11 in the upper section sprays ultra-high pressure water 1 and air to guide the pre-cutting of the soil and form a certain pre-formed hole 30. The second nozzle 12 in the lower section sprays ultra-high pressure hardening material 3 to continue to expand the pre-formed hole 30 and cut the soil. At the same time, under the action of air lift, the generated sediment and slurry can be smoothly discharged upward; the injection pressure of the ultra-high pressure hardening material 3 is greater, so that the reinforcement can be faster, but it is also necessary to avoid excessive injection pressure of the ultra-high pressure hardening material 3 affecting the structure of the adjacent overlapping second reinforcement body 120.

[0103] In addition, the pre-formed hole 30 exceeds a certain height of the ultra-high pressure jet grouting pile, and the height is determined by the spacing between the upper and lower nozzles; the spacing between the upper and lower nozzles of the drill rod can be adjusted as needed.

[0104] It can be understood that in the embodiment of the present application, the diameter of the lead hole 20 and the parameters of the first nozzle 11 and the second nozzle 12 have a certain matching relationship, and the parameters of the first nozzle 11 and the second nozzle 12 are directly related to the pile diameter and the height of the reinforcement body.

[0105] Optionally, the distance between the first nozzle 11 and the second nozzle 12 on the jet grouting drill rod 10 is 1.2 m to 1.4 m; it should be noted that the larger the distance between the first nozzle 11 and the second nozzle 12, the Fig.12 As shown, it means that the water and air removed from the soil by the first nozzle 11 will cause less disturbance to the reinforced slurry 5 mixed with the high pressure hardening material 3 and cement slurry 4 ejected from the second nozzle 12. Fig.13 As shown, the disturbance and pressure generated will take away most of the reinforcement slurry 5. The spacing between the first nozzle 11 and the second nozzle 12 can also prevent the invalid lead hole 21 from being too deep, wasting the cost and time of the lead hole 20; most importantly, if the invalid lead hole 21 is too long, the reinforcement slurry is not conducive to filling the invalid lead hole 21, so that the invalid lead hole 21 may still be a mixture of soil and water, causing danger to the reinforced structure. After research in this application, setting 1.2m to 1.4m can combine the above factors to achieve an optimization effect.

[0106] Optionally, when forming the first reinforcement body 110, the pressure of the high-pressure water 1 of the first nozzle 11 is 25MPa-37MPa, and the flow rate is 150L / min-200L / min; the pressure of the high-pressure air 2 is 0.75MPa-1.25MPa, and the flow rate is 4.5Nm 3 / min~5.5N m 3 / min; the pressure of the high-pressure hardening material 3 of the second nozzle 12 is 37MPa~42MPa, and the flow rate is 115L / min~135L / min; the injection radius of the first nozzle 11 is 85%~90% of the radius of the first reinforcement body 110; the injection radius of the second nozzle 12 is 10%~15% of the radius of the first reinforcement body 110.

[0107] When forming the second reinforcement body 120, the pressure of the high-pressure water 1 of the first nozzle 11 is 35MPa-45MPa, and the flow rate is 180L / min-220L / min; the pressure of the high-pressure air 2 is 1.05MPa-1.75MPa, and the flow rate is 5.0Nm 3 / min~6.5Nm 3 / min; the pressure of the high-pressure hardening material 3 of the second nozzle 12 is 40MPa~45MPa, and the flow rate is 120L / min~155L / min; the injection radius of the first nozzle 11 is 85%~90% of the radius of the second reinforcement body 120; the injection radius of the second nozzle 12 is 10%~15% of the radius of the second reinforcement body 120.

[0108] The specific parameter settings are shown in Table 2 below.

[0109] Table 2

[0110]

[0111] In the embodiment of the present application, by controlling the return slurry channel of the guide hole 20 and the rotary jet drill rod 10, sufficient space can be reserved. During the ultra-high pressure reinforcement rotary jetting, the situation in which the groove wall collapses and the rotary jet drill rod 10 is locked can be effectively avoided, thereby saving time for troubleshooting and improving reinforcement efficiency.

[0112] In the embodiment of the present application, by controlling the size of the guide hole 20, it is beneficial for the first ultra-high pressure air 2 and ultra-high pressure water 1 to cut into a larger cylinder, reduce the soil near the drill rod, reduce energy loss, and make effective use of the energy of the ultra-high pressure air 2 and ultra-high pressure water 1, spray farther, and increase the cutting range, creating favorable conditions for the second ultra-high pressure hardening material 3 cutting.

[0113] Another important improvement point in the present application is the matching of the pre-cutting and secondary cutting ranges. First, since the upper high-pressure air 2 packs high-pressure water 1 to cut the pile body, the reinforcement body cut by the high-pressure air 2 packs high-pressure water 1 needs 85-90% of the pile diameter, and the remaining 10-15% of the pile diameter of the reinforcement body is cut by the high-pressure slurry of the lower nozzle. Second, the high-pressure slurry of the lower nozzle plays the role of expanding the pile body and further spraying slurry during the entire reinforcement process, stirring the lower mixed liquid, thereby making the strength of the reinforcement body more uniform, and can also leave more slurry of the hardening material 3 to improve the replacement rate. Under the condition of applying the same hardening material 3, a reinforcement body with a larger pile diameter, better reinforcement quality, a smaller permeability coefficient, and a greater reinforcement strength can be obtained.

[0114] It can be understood that in the embodiment of the present application, the first reinforcement body 110 and the second reinforcement body 120 are both cylindrical, the rotary spraying angle of the first nozzle 11 and the second nozzle 12 can be 360°, and in different embodiments, any angle can be used for rotary spraying according to the design requirements; the pressure used for rotary spraying of the ultra-high pressure air 2, ultra-high pressure water 1, and ultra-high pressure hardening material 3 slurry can be adjusted as needed. In addition, the above process parameters are only for experimental reference and work together with the properties of the soil, reinforcement depth, etc. At the same time, the diameter of the reinforcement pile is also related to the characteristics of the soil. The diameter of the pile is large for sandy soil and small for clay soil.

[0115] Example

[0116] S1: The site is leveled, and a steel casing of a certain depth is buried on the site corresponding to each of the above-mentioned lead hole positions, for example, a 3-4m deep steel casing is buried. In order to prevent the cement slurry 4 of the lead hole 20 pre-hole 30 and the return slurry of the reinforced soil from being discharged everywhere, a temporary return slurry collection pit 40 is excavated at the top of the reinforced body.

[0117] A mud discharge device 50 is provided at the location of the temporary collection pit 40 to absorb the cement slurry 4, which can control the pressure inside the ground. If the pressure is too high, the cement slurry 4 can be actively pumped out to reduce the pressure inside the ground, so that the ultra-high pressure hardened material and the air spray fluid are under the same spraying pressure, which can make the reinforcement more uniform and the reinforcement quality better.

[0118] S2: The large-diameter pilot hole 20 drilling rig is in place, assisted by high-quality mud wall protection, and a 60cm drill bit is used to drill the pre-hole 30. The verticality is measured every 10m. If there is any deviation, it is corrected and adjusted in time until the pilot hole 20 is 1.4m deeper than the second reinforcement body 120.

[0119] S3: The ultra-high pressure jet grouting equipment is put in place, the equipment level is accurately adjusted, and it is aligned with the designed pile center position, and then the jet grouting drill rod 10 is lowered with the assistance of a truck crane.

[0120] S4: After the jet grouting drill rod 10 is lowered into place, the backstage air compressor is started to deliver high-pressure air 2, the high-pressure water pump 1 delivers high-pressure water 1, the first nozzle 11 of the upper section of the jet grouting drill rod 10 is opened, the ultra-high pressure jet grouting equipment rotates the drill rod, the first nozzle 11 rotates 360° with the drill rod and sprays a mixed flow of ultra-high pressure water 1 and high-pressure air 2 to pre-cut the upper section of the original soil, and at the same time, the jet grouting drill rod 10 is slowly lifted according to the setting, so as to pre-cut the soil upward continuously, and form cement slurry 4 in the cylindrical space, so as to achieve the purpose of expanding the pile body and cutting the soil body for the first time;

[0121] S5: At the same time, part of the cement slurry 4 is discharged upward through the return slurry channel under the combined effect of the air lift and the continuously injected high-pressure water 1, and the excess cement slurry 4 is pumped away by the mud discharge equipment 50.

[0122] S6: The background high-pressure slurry equipment automatically mixes the slurry of the ultra-high pressure hardening material 3, and its mix ratio is configured according to the design.

[0123] S7: After the rotary jet drill pipe 10 is lifted and the first nozzle 11 cuts the original soil of the upper section of 1.4m, the second nozzle 12 of the lower section is immediately opened. The second nozzle 12 rotates 360° with the drill pipe and sprays the ultra-high pressure hardening material 3 liquid. Under the action of ultra-high pressure, the ultra-high pressure hardening material 3 slurry cuts the original soil again to form a spatial cylinder that meets the pile diameter requirements. At the same time, under the action of the spray, the ultra-high pressure hardening material 3 slurry and the cement slurry 4 are fully stirred and mixed, thereby forming a reinforced solid slurry 5 of the ultra-high pressure hardening material 3 and the cement slurry 4.

[0124] S8: While the second nozzle 12 is rotating and spraying, the upper part of the cement slurry 4 is removed by the reliable return slurry channel under the combined effect of air lift and the continuously injected high-pressure water 1, high-pressure air 2, and ultra-high-pressure hardening material 3, and the excess cement slurry 4 is pumped away by the mud discharge equipment 50.

[0125] S9: According to the setting, the jet grouting drill rod 10 is slowly lifted at the set step distance and rotated 360° to spray until the designed pile top is reinforced, the first nozzle 11 and the second nozzle 12 are stopped from spraying grouting, and the second reinforcement body 120 is removed to carry out the next construction.

[0126] In an embodiment of the present application, the first reinforcement body 110 and the second reinforcement body 120 at corresponding positions are formed by one rotary grouting hardening method through the same rotary grouting drill rod 10; the process parameters of the rotary grouting hardening of the first reinforcement body 110 and the second reinforcement body 120 are different. After completing the rotary grouting hardening of the first reinforcement body 110 and the second reinforcement body 120, the rotary grouting drill rod 10 is removed together to carry out the next construction.

[0127] The method further comprises:

[0128] The jet-jet drill rod 10 is removed, and after the reinforcement slurry is initially set, grouting is again performed in the lead hole 20 to form a secondary filling.

[0129] S10: After one day, before the slurry in the lead hole 20 channel hardens, and after the chemical reaction with the ultra-high pressure hardening material 3 liquid + soil particle mixture is initially solidified, in order to ensure the quality of the deep reinforcement pile design at the top of the pile, the pile top is subjected to secondary ordinary grouting to fill the pile head for the second time to ensure the quality of the pile head. It is understandable that the first reinforcement body 110 and the second reinforcement body 120 that are simultaneously jet-hardened can be grouted once or twice, and this application does not limit this.

[0130] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0131] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0132] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in the technical field of the present invention. The terms used herein are only for describing specific implementation purposes and are not intended to limit the present invention. Terms such as "setting" and the like appearing in this article can mean that one component is directly attached to another component, or that one component is attached to another component through an intermediate. Features described in this article in one embodiment may be applied to another embodiment alone or in combination with other features, unless the feature is not applicable in the other embodiment or otherwise specified.

[0133] The present invention has been described through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and illustration, and are not intended to limit the present invention to the described embodiments. It can be understood by those skilled in the art that more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention.

Claims

1. A bridge foundation reinforcement structure, characterized in that: It includes a wall reinforcement area and a central reinforcement area arranged inside the wall reinforcement area, the central reinforcement area includes a first reinforcement area and a second reinforcement area, the first reinforcement area includes a plurality of first reinforcement bodies arranged in an array, and two adjacent first reinforcement bodies are arranged tangentially; the second reinforcement area includes a plurality of second reinforcement bodies arranged in an array, and two adjacent second reinforcement bodies partially overlap; each of the first reinforcement bodies is reinforced and formed once, and each of the second reinforcement bodies is reinforced and formed once; The first reinforcement area and the second reinforcement area are stacked, the first reinforcement area is arranged on the upper layer of the second reinforcement area, the axis of the first reinforcement body and the second reinforcement body at the corresponding position coincide with each other, and the first reinforcement body and the second reinforcement body are coaxially constructed and reinforced in one step; the wall reinforcement area includes a first edge reinforcement body arranged on the same layer as the first reinforcement body and a second edge reinforcement body arranged on the same layer as the second reinforcement body, and two adjacent second edge reinforcement bodies partially overlap; the axis of the first edge reinforcement body and the second edge reinforcement body at the corresponding position coincide with each other; The central reinforcement area includes a first deep area I, a second deep area II, and a third deep area III which are arranged in succession. The height of the first deep area I is less than the height of the third deep area III. The height of the first reinforcement body in the first deep area I is less than the height of the first reinforcement body in the third deep area III. The height of the second reinforcement body in the first deep area I is equal to the height of the second reinforcement body in the third deep area III. The height of the first reinforcement body in the second deep area II is equal to the height of the first reinforcement body in the first deep area I. The height of the second reinforcement body in the second deep area II is greater than the height of the second reinforcement body in the third deep area III.

2. The bridge foundation reinforcement structure according to claim 1, characterized in that: The height of the first reinforcement body is greater than the height of the second reinforcement body, the diameter of the first reinforcement body is smaller than the diameter of the second reinforcement body, the diameters of the first edge reinforcement body and the first reinforcement body are the same, and the diameters of the second edge reinforcement body and the second reinforcement body are the same; the center distance between two adjacent first edge reinforcement bodies is smaller than the center distance between two adjacent first reinforcement bodies, and the center distance between two adjacent second edge reinforcement bodies is smaller than the center distance between two adjacent second reinforcement bodies.

3. The bridge foundation reinforcement structure according to claim 1, characterized in that: The first reinforcement body has a height of 20m~27m and a diameter of 1.5m~2m; The height of the second reinforcement body is 4m~8m and the diameter is 2.4m~3m; The bottom depth of the first reinforcement body is 40m~51m; The bottom depth of the second reinforcement body is 48m~55m.

4. A construction method for a bridge foundation reinforcement structure, characterized in that: Used to form the bridge foundation reinforcement structure as claimed in any one of claims 1 to 3, the construction is carried out by using a jet grouting drill rod, the jet grouting drill rod comprises a first nozzle and a second nozzle arranged up and down, the first nozzle is used to spray high-pressure water and high-pressure air, and the second nozzle is used to spray high-pressure hardening material; the method comprises: Forming a lead hole at the axial position of the first reinforcement body and the second reinforcement body; A plurality of first reinforcement bodies and a plurality of second reinforcement bodies arranged in an array are formed by extending a jet grouting drill rod into the guide hole and hardening the plurality of first reinforcement bodies by jet grouting; The first reinforcement body and the second reinforcement body are reinforced and formed at one time by extending the same jet grouting drill rod into the same guide hole for coaxial construction, and by jet grouting hardening; The method of the rotary spray hardening specifically includes: The soil is pre-cut by rotating and spraying high-pressure water and high-pressure air through the first nozzle to expand the pile body and form a cement slurry of water and native soil; The soil is cut for a second time by rotating and spraying the high-pressure hardening material through the second nozzle to expand the pile body again and form a reinforced body slurry of the hardening material and cement slurry.

5. The construction method of the bridge foundation reinforcement structure according to claim 4, characterized in that: Before forming the lead hole, the method further includes: A steel casing of a certain depth is buried on the site corresponding to each of the lead hole positions, and a collection pit for collecting the cement slurry and the reinforcement slurry is opened at each of the lead hole positions.

6. The construction method of the bridge foundation reinforcement structure according to claim 4, characterized in that: The diameter of the lead hole is 40 cm to 65 cm; the diameter of the jet grouting drill rod is 10 cm to 20 cm; the spacing between the lead hole and the jet grouting drill rod to form a return slurry channel is 15 cm to 20 cm; The method for forming the lead hole comprises: Drilling is done by using a drill bit with the aid of mud wall protection; The verticality measurement is performed once at every fixed height to ensure that the verticality deviation of the lead hole is ≤1 / 300.

7. The construction method of the bridge foundation reinforcement structure according to claim 4, characterized in that: The first nozzle is close to the upper surface of the foundation, and the second nozzle is far from the upper surface of the foundation. The first nozzle and the second nozzle are arranged on opposite sides of the jet grouting drill rod. The diameter of the pile body formed by pre-cutting by the first nozzle is smaller than the diameter of the pile body formed by secondary cutting by the second nozzle. The operation method of the rotary grouting hardening includes: the rotary grouting drill rod is lifted while rotating and spraying, from the bottom of the guide hole upward, and after the first nozzle rotates and sprays to a certain height, the second nozzle is opened for selective spraying.

8. The construction method of the bridge foundation reinforcement structure according to claim 4, characterized in that: The distance between the first nozzle and the second nozzle on the jet jet drill rod is 1.2m~1.4m; When forming the second reinforcement body, the pressure of the high-pressure water of the first nozzle is 35MPa~45MPa, and the flow rate is 180L / min~220L / min; the pressure of the high-pressure air is 1.05MPa~1.75MPa, and the flow rate is 5.0Nm 3 / min~6.5Nm 3 / min; the pressure of the high-pressure hardening material of the second nozzle is 40MPa~45MPa, and the flow rate is 120L / min~155L / min; the injection radius of the first nozzle is 85%~90% of the radius of the second reinforcement body; the injection radius of the second nozzle is 10%~15% of the radius of the second reinforcement body; When forming the first reinforcement body, the pressure of the high-pressure water of the first nozzle is 25MPa~37MPa, and the flow rate is 150L / min~200L / min; the pressure of the high-pressure air is 0.75MPa~1.25MPa, and the flow rate is 4.5Nm 3 / min~5.5Nm 3 / min; the pressure of the high-pressure hardening material of the second nozzle is 37MPa~42MPa; the spraying radius of the first nozzle is 85%~90% of the radius of the first reinforcement body; the spraying radius of the second nozzle is 10%~15% of the radius of the first reinforcement body.

9. The construction method of the bridge foundation reinforcement structure according to claim 4, characterized in that: The method further comprises: The jet-jet drill rod is removed, and after the reinforcement slurry is initially set, grouting is again performed in the lead hole to form a secondary filling.

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