CN116290064A - Bridge ultra-deep foundation reinforcement structure and construction method thereof - Google Patents

Abstract

The application discloses a bridge ultra-deep foundation reinforcement structure and its construction method, including a wall reinforcement area and a central reinforcement area arranged inside the wall reinforcement area, the central reinforcement area includes the first reinforcement area and/or the second reinforcement area, No. A reinforcement area includes a plurality of first reinforcements arranged in an array, and two adjacent first reinforcements are arranged tangentially; a second reinforcement area includes a plurality of second reinforcements arranged in an array, and there is a partial intersection between two adjacent second reinforcements. stack; each first reinforcement body is a reinforcement molding, and each second reinforcement body is a reinforcement molding; when the central reinforcement area includes the first reinforcement area and the second reinforcement area, the first reinforcement area and the second reinforcement area Layered arrangement, the first reinforcement area is set 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 at one time .

Description

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

technical field

The application generally relates to the technical field of construction engineering, and specifically relates to a super-deep foundation reinforcement structure of a bridge and a construction method thereof.

Background technique

The anchorage is located on the alluvial river center island. The bedrock in the project site is buried deeper than 100m, and the soft covering layer is more than 50m thick. Bearing layer traditionally required for connecting walls. The sand layer near the bottom of the foundation pit is a highly permeable and confined aquifer. The water head of the confined water is high, and there is no natural water-resisting layer at the base. The anti-slip requirements at the bottom are high. However, the bottom of the foundation pit in the prior art is not only risky during the construction period, it is basically impossible to construct. How to solve the water resistance, bearing capacity and anti-slip of the bottom of the foundation pit during the construction process And so on is the key.

Contents of the invention

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

In a first aspect, the present application provides a bridge foundation reinforcement structure, including 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/or a second reinforcement area, so The first reinforcement area includes a plurality of first reinforcements arranged in an array, and two adjacent first reinforcements are arranged tangentially; the second reinforcement area includes a plurality of second reinforcements arranged in an array, and two adjacent second reinforcements Partial overlap of solids exists; each of the first reinforcements is formed by one reinforcement, and each of the second reinforcements is formed by one reinforcement;

When the central reinforced area includes the first reinforced area and the second reinforced area, the first reinforced area and the second reinforced area are stacked, and the first reinforced area is arranged on the second reinforced area. In the upper layer of the reinforcement area, the axis of the first reinforcement body and the second reinforcement body at the corresponding position are coincident, and the first reinforcement body and the second reinforcement body are coaxially constructed and reinforced at one time.

Optionally, the wall reinforcement area includes a first edge reinforcement disposed on the same layer as the first reinforcement and a second edge reinforcement disposed on the same layer as the second reinforcement, and two adjacent second edges There is a partial overlap of the reinforcements; the axes of the first edge reinforcement and the second edge reinforcement at the corresponding positions are coincident.

Optionally, the height of the first reinforcement is greater than the height of the second reinforcement, the diameter of the first reinforcement is smaller than the diameter of the second reinforcement, and the first edge reinforcement and the The diameter of the first reinforcement is the same, the diameter of the second edge reinforcement is the same as that of the second reinforcement; the center distance between two adjacent first edge reinforcements is smaller than that of the adjacent two first reinforcements The center-to-center distance of the solids is smaller than the center-to-center distance between two adjacent second edge reinforcements.

Optionally, the first reinforcing body has a height of 20m-27m and a diameter of 1.5m-2m;

The second reinforcing body has a height of 4m-8m and a diameter of 2.4m-3m;

The depth of the bottom surface of the first reinforcement is 40m-51m;

The depth of the bottom surface of the second reinforcement is 48m-55m.

In the 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 by using rotary jet drilling rods, and the rotary jet drilling rods include vertically arranged A first nozzle and a second nozzle, 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:

forming guide holes at the axial positions of the first reinforcement and/or the second reinforcement;

forming a plurality of first reinforcements and/or a plurality of second reinforcements arranged in an array through rotary spraying drill rods inserted into the guide hole and hardened by rotary spraying;

When the central reinforcement area includes the first reinforcement area and the second reinforcement area, the same rotary spraying drill pipe is inserted into the same guide hole for coaxial construction, and the rotary spraying hardening is performed once Reinforcing the first reinforcement body and the second reinforcement body;

Wherein, the manner of said rotary spray hardening specifically includes:

Pre-cutting the soil body by 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 second nozzle rotates and sprays the high-pressure hardening material to cut the soil twice, so as to expand the pile body again and form a solid slurry of hardening material and cement slurry.

Optionally, before forming the introduction hole, the method further includes:

A steel casing of a certain depth is buried on the site corresponding to each of the introduction holes, and a collection pit for collecting the cement slurry and the reinforcement slurry is opened at each of the introduction hole locations.

Optionally, the diameter of the introduction hole is 40cm-65cm; the diameter of the jet-jet drill pipe is 10cm-20cm; 20cm;

The method for forming a hole includes:

Drilling through the drill bit supplemented by mud retaining walls;

Perpendicularity measurement is performed at intervals of fixed heights to ensure that the verticality deviation of the pilot hole is ≤1/300.

Optionally, the first nozzle is close to the upper surface of the foundation, the second nozzle is away from the upper surface of the foundation, the first nozzle and the second nozzle are arranged on opposite sides of the rotary jet drill pipe, and the first nozzle The diameter of the pile body formed by pre-cutting is smaller than the diameter of the pile body formed by secondary cutting of the second nozzle;

The operation mode of the rotary spray hardening includes: the rotary spray drill rod adopts the method of lifting while rotating and spraying, from the bottom of the guide hole upwards, and then opens the second nozzle after the first nozzle rotates and sprays to a certain height Perform selective injection.

Optionally, the distance between the first nozzle and the second nozzle on the jet-jet drill pipe is 1.2m-1.4m;

When forming the second reinforced body, the pressure of the high-pressure water in 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, the flow rate is 120L/min～155L/min; the spray radius of the first nozzle is the radius of the second reinforced body 85%-90% of that; the spray radius of the second nozzle is 10%-15% of the radius of the second reinforcement;

When forming the first reinforced body, the pressure of the high-pressure water in 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 spray radius of the first nozzle is 85%～90% of the radius of the first reinforcement; The spraying radius of the second nozzle is 10%-15% of the radius of the first reinforcing body.

Optionally, the first reinforcement body and the second reinforcement body at the corresponding positions are formed by two times of jet-spray hardening through the same jet-jet drill pipe;

The method also includes:

In addition to the jet-jet drill pipe, after the initial setting of the reinforcement slurry, grouting is performed again in the guide hole to form secondary filling.

The technical solutions provided by the embodiments of the present application may include the following beneficial effects:

The bridge ultra-deep foundation reinforcement structure provided by the embodiment of the present application is suitable for bridge ultra-deep foundations. The purpose of foundation reinforcement can be achieved through the setting of double-layer reinforcements, forming a structure with ultra-high reinforcement strength, friction coefficient that meets the requirements, and low permeability coefficient. "Artificial water-resisting layer", so as to meet the needs of the anchorage ground and wall foundation for the bearing layer, friction layer and water sealing layer.

Description of drawings

Other characteristics, 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:

Fig. 1 is a structural schematic diagram of a reinforcement structure provided by an embodiment of the present application;

Fig. 2 is a schematic cross-sectional view of a reinforcement structure provided by an embodiment of the present application;

Fig. 3 is a schematic layout diagram of a reinforcing structure provided by the embodiment of the present application;

Fig. 4 is a schematic layout diagram of a first reinforcement zone provided by the embodiment of the present application;

Fig. 5 is a schematic layout diagram of a second reinforcement area provided by the embodiment of the present application;

Fig. 6 is a structural schematic diagram of a reinforcement structure construction position provided by an embodiment of the present application;

Figure 7-10 is a construction schematic diagram of a rotary spray hardening provided by the embodiment of the present application;

Fig. 11 is a schematic diagram of the soil between the piles at the position of the pilot hole provided by the embodiment of the present application;

Fig. 12 is a schematic diagram of a slurry discharge of a rotary jet drill pipe provided by an embodiment of the present application;

Fig. 13 is a schematic diagram of a slurry discharge of a rotary jet drill pipe provided in an embodiment of the present application.

In the figure,

100, wall reinforcement area; 200, central reinforcement area; 300, ground connection wall bottom; 400, outer wall;

110. First reinforcement; 120. Second reinforcement; 130. First edge reinforcement; 140. Second edge reinforcement;

D1, the first reinforcement zone; D2, the second reinforcement zone; I, the first deep zone; II, the second deep zone; III, the third deep zone;

10. Rotary spray drill pipe; 11. The first nozzle; 12. The second nozzle;

20. Lead hole; 21. Invalid lead hole; 30. Preformed hole;

40. Collection pit; 50. Sludge discharge equipment;

1. High pressure water; 2. High pressure air; 3. Hardened material; 4. Cement slurry; 5. Reinforced solid slurry.

Detailed ways

The application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain related inventions, rather than to limit the invention. It should also be noted that, for ease of description, only parts related to the invention are shown in the drawings.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

Please refer to Figures 1-2 for details. The present application provides a bridge foundation reinforcement structure, which includes a wall reinforcement area 100 and a central reinforcement area 200 disposed inside the wall reinforcement area 100. The central reinforcement area 200 includes a stacked first The reinforced area D1 and/or the second reinforced area D2, the first reinforced area D1 includes a plurality of first reinforced bodies 110 arranged in an array, and two adjacent first reinforced bodies 110 are arranged tangentially; the second reinforced area D2 It includes a plurality of second reinforcements 120 arranged in an array, and two adjacent second reinforcements 120 partially overlap;

Each of the first reinforcements 110 is formed by one reinforcement, and each of the second reinforcements 120 is formed by one reinforcement; the central reinforcement area 200 includes the first reinforcement area D1 and the second reinforcement area. In the area D2, the first reinforcement area D1 and the second reinforcement area D2 are arranged in layers, the first reinforcement area D1 is arranged on the upper layer of the second reinforcement area D2, and the first reinforcement body 110 and the corresponding The axes of the second reinforcing body 120 at the position are coincident, and the first reinforcing body 110 and the second reinforcing body 120 are coaxially constructed and reinforced at one time.

The bridge ultra-deep foundation reinforcement structure provided in the embodiment of this application is suitable for bridge ultra-deep foundations. The purpose of foundation reinforcement can be achieved through the setting of double-layer reinforcements, and the formation has ultra-high reinforcement strength, friction coefficient meets requirements, and permeability coefficient is small. The "artificial water-resisting layer" can meet the needs of the anchorage ground and wall foundation for the bearing layer, friction layer and water sealing layer.

It can be understood that, FIG. 1 shows a schematic structural diagram of a part of the central reinforcement area in the reinforcement structure, wherein part of the first reinforcement 110 is removed from the first reinforcement layer D1, and the first reinforcement is not shown in FIG. 2 110 and a separate structure of the second reinforcing body 120. Figure 3 shows the arrangement of each reinforcing body in a reinforcing structure, wherein the upper semicircle is the first reinforcing body 110 on the first reinforcing layer D1 and the first reinforcing body 110 on the wall reinforcement area 100 on the same floor as the first reinforcing layer D1. A schematic layout of an edge reinforcement 130; the lower semicircle is a schematic layout of the second reinforcement 120 on the second reinforcement layer D2 and the second edge reinforcement 140 on the wall reinforcement area 100 on the same floor as the second reinforcement layer D2.

In this embodiment, the wall reinforcement area 100 includes a first edge reinforcement 130 disposed on the same layer as the first reinforcement 110 and a second edge reinforcement 140 disposed on the same layer as the second reinforcement 120 , Two adjacent second edge reinforcements 140 partially overlap; axes of the first edge reinforcement 130 and the second edge reinforcement 140 at the corresponding position coincide.

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 at the central area of the outer wall 400, and the wall reinforcement area is set at the In the area near the wall reinforcement area on the periphery of the central reinforcement area 200, the outer layer of dense waterproof and reinforcement can be formed through the wall reinforcement area. In this application, the first edge reinforcement 130 on the wall reinforcement area 100 is connected with the first reinforcement The solid 110 partially overlaps, the second edge reinforcement 140 and the second reinforcement 120 also partially overlap, and at the same time, both the first edge reinforcement 130 and the second edge reinforcement 140 partially overlap the outer wall 400, which can Improve the connection strength of the reinforced structure and increase the edge permeability coefficient.

When arranged, the height of the first reinforcement 110 is greater than the height of the second reinforcement 120, the diameter of the first reinforcement 110 is smaller than the diameter of the second reinforcement 120, and the first edge reinforcement The solid 130 has the same diameter as the first reinforcement 110, the second edge reinforcement 140 has the same diameter as the second reinforcement 120; the center-to-center distance between two adjacent first edge reinforcements 130 is smaller than the The center-to-center distance between two adjacent first reinforcements 110 , the center-to-center distance between two adjacent second edge reinforcements 140 is smaller than the center-to-center distance between two adjacent second reinforcements 120 .

In one embodiment of the present application, as shown in FIG. 3 , the central reinforcement zone 200 includes a first deep zone I, a second deep zone II, and a third deep zone III arranged continuously, and the first deep zone I The height of the first reinforcement 110 in the first deep region I is less than the height of the third deep region III, the height of the first reinforcement 110 in the first deep region I is smaller than the height of the first reinforcement 110 in the third deep region III, the first The height of the second reinforcement 120 in the deep zone I is equal to the height of the second reinforcement 120; the height of the first reinforcement 110 in the second deep zone II is equal to the height of the first deep zone II The height of the first reinforcement 110 in I, the height of the second reinforcement 120 in the second deep region II is equal to the height of the second reinforcement 120 in the third deep region III.

It can be understood that when the reinforcement structure provided by the application is applied to bridge structures, depending on the application location, there may be different stress conditions at different positions of the same reinforcement structure. For the bearing capacity of the third deep zone III, in this application, the method of increasing the height of the first reinforcement body 110 can be adopted to increase the bearing capacity of the reinforced structure within the range of the third deep zone III and save costs. In addition, in order to improve the transition ability between the first deep zone I and the third deep zone III and prevent problems such as stress concentration, a transitional third zone is set between the first deep zone I and the third deep zone III in this application. In the second deep zone II, by increasing the height of the second reinforcing body 120 within the scope of the second deep zone II, the bearing capacity of the transition zone is increased and the stress of the first deep zone I and the second deep zone II is balanced to increase the life of the reinforced structure.

The height of the first reinforcing body 110 described in the embodiment of the present application is 20m-27m, and the diameter is 1.5m-2m;

The second reinforcing body 120 has a height of 4m-8m and a diameter of 2.4m-3m;

The depth of the bottom surface of the first reinforcing body 110 is 40m-51m;

The depth of the bottom surface of the second reinforcing body 120 is 48m-55m.

It can be understood that the embodiment of the present application does not limit the cross-sectional shape of the reinforcement structure formed by the plurality of reinforcement bodies, and may be regular shapes such as circles, squares, triangles, and borderless shapes or other irregular shapes, depending on specific applications. set according to the scene, etc. In the embodiments of the present application, circular cross sections are used for exemplary description.

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

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 (intersection) Stack size) is 0.7m where the arrangement of the first reinforcement area D1 and the second reinforcement area D2 is shown in Table 1 below.

Table 1

It can be seen from the above table that the reinforcement structure in this application is suitable for ultra-deep foundations, and the depth of the foundation exceeds 50m. However, the current existing methods cannot realize the formation of the second reinforcement body 120 with a diameter exceeding 2.4m at an ultra-deep height of 50m. Formation, generally, if the reinforcement is too deep and the pressure in the ground is too large, the rotational hardening method will offset the energy of a part of ultra-high pressure hardened material and air jet fluid or ultra-high pressure water 1 and air jet fluid, making the pile diameter At the same time, because the reinforcement is too deep, the effect of gas lift is not very good, resulting in the unsmooth return of slurry, which further increases the pressure in the ground, and it is easy to collapse holes during reinforcement, which will lock the drill pipe, thereby increasing the risk and difficulty of construction. In the formation method of the reinforcement structure in the prior art, the theoretical pile diameter is 3m within 20m, and the pile diameter is reduced by 20cm for every 10m thereafter. According to actual tests, it is difficult to reach a pile diameter of 2.4m at a depth of 50m.

Based on this ultra-deep foundation, the 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 a rotary grouting drill pipe 10 as shown in Figure 6. construction, the rotary grouting drill pipe 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 hardened material 3; the method comprising:

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

When the central reinforcement area 200 includes the second reinforcement 120, the method includes: S200, inserting the rotary grouting drill pipe 10 into the introduction hole 20 and hardening by rotary spraying to form a plurality of second reinforcements arranged in an array 120;

When the central reinforcement area 200 includes the second reinforcement 120, the method includes: S300, inserting the rotary grouting drill pipe 10 into the introduction hole 20 and hardening by rotary spraying to form a plurality of first reinforcements arranged in an array 110;

When the central reinforcement zone 200 includes the first reinforcement zone D1 and the second reinforcement zone D2, the same rotary grouting drill pipe 10 is inserted into the same guide hole 20 for coaxial construction, The first reinforcement body 110 and the second reinforcement body 120 are reinforced and formed in one shot by spray hardening.

Wherein, as shown in Figure 7-10, the method of rotary spray hardening specifically includes:

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

ST04. The second nozzle 12 rotates and sprays the high-pressure hardening material 3 to cut the soil twice, so as to expand the pile body again and form the reinforcement slurry 5 of the hardening material 3 and the cement slurry 4 .

In the construction method provided by this application, the original soil concrete formed by cutting 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, and at the same time, the second The ultra-high pressure hardening material 3 sprayed by the nozzle 12 forms a secondary cutting and forms a reinforced solid slurry 5, which is also conducive to the removal of the original soil cement slurry, thereby reducing the internal pressure, effectively retaining the secondary cutting energy of the lower section, and forming a larger diameter pile .

In the construction method provided by this application, in this application, 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 forced against each other, and the injection force provided by the second nozzle 12 of the lower section will move upward. With the waste cement slurry 4 discharged, the injection force provided by the first nozzle 11 in the upper section presses the slurry of the ultra-high pressure hardening material 3 in the lower section tightly on the lower side of the introduction hole 20 for filling, so that a very small part of the ultra-high pressure The hardened material 3 slurry is brought out.

It can be understood 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 slurry of the ultra-high-pressure hardening material 3 from being guided upward by a large part under the action of gas lift. reinforcement slurry. If the injection process in the second nozzle 12 contains high-pressure air 2, then in the injection process, the reinforcement and hardening material 3 is brought out by returning slurry to about 20% of the reinforcement, that is, 20% of the hardening material 3 is wasted. The method of spraying the high pressure hardening material 3 from the second nozzle 12 can improve the replacement rate of the ultra high pressure hardening material.

The construction method provided by this application, under the premise of ensuring the strength, friction coefficient and permeability coefficient of the upper and lower composite reinforced soil, reasonably increases the replacement rate of reinforcement and hardening materials 3, reduces the consumption of reinforcement and hardening raw materials, saves the investment of hardening raw materials, and reduces the project cost. cost input. The same reinforcement effect can be achieved by injecting fewer raw materials. At the same time, the use of large-diameter guide holes 20 can improve the verticality of the reinforcement body and ensure the occlusal effect. At the same time, a reliable slurry return channel can be established to reduce the internal pressure. The ultra-high pressure hardening material and the air jet fluid create good conditions to ensure the diameter and quality of the reinforcement.

It should be noted that the embodiment of the present application does not limit the formation sequence of the first reinforcement 110 and the second reinforcement 120 at the corresponding position. In some embodiments, the first reinforcement can be formed simultaneously based on the same guide hole 20 The solid 110 and the second reinforced body 120, for example, adopt the second rotary spraying process on the corresponding second reinforced layer, and then use the first rotary spraying process to continue to form the first reinforced body 110 after being raised to a certain height. In some other embodiments, each second reinforcement body 120 can be formed on the second reinforcement area D2 first, and then each first reinforcement body 110 can be formed on the first reinforcement body 110 area after the second reinforcement body 120 is hardened and formed. , because the reinforcement structure provided in this application can be formed in various ways, which can be selected according to scenarios or costs in specific applications, and this application is not limited.

In the embodiment of the present application, the diameter of the introduction hole 20 is 40 cm to 65 cm; the diameter of the rotary jet drill pipe 10 is 10 cm to 20 cm; The distance between the slurry channels is 15cm-20cm. Exemplarily, the diameter of the jet-jet drill pipe 10 is 11 cm, the diameter of the guide hole 20 is between 40-65 cm, and the radius difference on both sides is 15-20 cm, that is, the space of the slurry return channel is a ring of 15-20 cm.

In the construction method provided in this application, an important point of improvement lies in the setting of the introduction hole 20 and the setting of the diameter of the introduction hole 20. The setting of the introduction hole 20 in this application is conducive to establishing a reliable grout return channel and reducing the internal pressure of the reinforcement area. Reduce jet cutting energy loss.

The larger the diameter of the guide hole 20 means that when the upper high-pressure air 2 and the high-pressure water 1 are cutting the pile, the farther they can touch the soil, and then the soil will be cut, but a part of the ejected energy will also be lost due to the suspension. After the lead hole 20 reached a certain diameter, the energy loss was completed, and the surrounding soil could not 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 input hole 20 equipment specifications will be larger, and the price of the lead hole 20 equipment will increase exponentially.

Most importantly, as shown in FIG. 11 , since the second reinforcing bodies 120 overlap (occlude) one by one, if the guide hole 20 (area A) is too large, the surrounding reinforcing bodies that have been piled will be destroyed. Simultaneously, the larger the lead hole 20 means that the area of the soil between the piles (B district) will be smaller, and the soil between the piles may collapse, resulting in the collapse of the hole and the locking of the drill pipe, resulting in a safety accident. In addition, if the guide hole 20 is as large as the reinforcement pile, concrete can be poured directly to form a concrete structure, and the cost will increase geometrically; more importantly, the second reinforcement in the second reinforcement layer in the embodiment of the present application 120 is arranged in an overlapping manner. If the guide hole 20 is too large, the overlapping second reinforcement 120 cannot be formed, thus failing to meet the requirement of full-section sealing. If the diameter of the pilot hole 20 is too small, the underground internal pressure is too large, causing part of the injection energy of the upper cutting soil to resist the internal pressure, and the remaining part will cut the soil, causing the diameter of the upper preformed hole 30 to be too small. . Therefore, under the same construction parameters, the pile diameter is small.

In the embodiment of the present application, the axes of the first reinforcement body 110 and the second reinforcement body 120 are coincident, and the same guide hole 20 is used to realize the rotation hardening of the second reinforcement body 120 and the upper layer of the first reinforcement body 110 . In step S100, the method for forming the lead hole 20 includes:

Drilling through the drill bit supplemented by mud retaining walls;

The verticality measurement is carried out at intervals of fixed heights to ensure that the verticality deviation of the guide hole 20 is ≤ 1/300.

Exemplarily, in order to satisfy the pile diameter of the second reinforcing body 120 of 2.4m, the pile spacing of 1.7m, the bite of 70cm, and the allowable deviation of only 22cm, in order to improve the water-stopping ability and bearing capacity, the verticality deviation should be less than 1/220.

During construction, use a 60cm drill bit to drill the pre-formed hole 30, and measure the verticality every 10m. If there is any deviation, correct and adjust it in time until the pilot hole 20 is 1.4m deeper than the designed pile body of the reinforced body. It can be understood that 1.4m is the depth of the guide hole 20, and the distance between the first nozzle 11 and the second nozzle 12 needs to be reserved, so that the first nozzle 11 of the rotary jet drill pipe 10 can perform rotary spraying at a preset position, as follows The introduction hole 20 describing the position below the second reinforcing body 120 is an invalid introduction hole 21 .

The verticality of the guide hole 20 is directly related to the exact position of the reinforced pile. This method adopts a large diameter guide hole 20 of 40 cm to 65 cm, which reserves space for adjusting the position in the process of the ultra-high pressure rotary grouting drilling machine, so that the drill pipe Under the action of gravity, it sags naturally, so that the verticality of the ultra-high pressure rotary grouting drill pipe 10 is no longer affected by the pre-formed hole 30 . It can be understood that the diameter of the guide hole 20 can be adjusted and optimized according to the height of the reinforcing body, and the specific adjusted size is mainly conducive to the establishment of a reliable slurry return channel and reserved adjustment space.

This application adopts the method of rotary jet hardening in steps S200 and S300, using high-pressure equipment to make high-pressure water and high-pressure air into high-pressure jets, which are ejected from the nozzles to impact and destroy the soil, and play the role of cutting the soil. In addition, the rotary spray The method can also realize the stirring function to form cement slurry, in which part of the fine soil material emerges from the water surface with the cement slurry, and the rest of the soil particles are stirred and mixed with the slurry under the impact force of the jet flow, centrifugal force and gravity, etc. Regularly rearrange according to a certain slurry-to-soil ratio.

Wherein, the first nozzle 11 is close to the upper surface of the foundation, the second nozzle 12 is away from the upper surface of the foundation, and the first nozzle 11 and the second nozzle 12 are arranged on opposite sides of the rotary jet drill pipe 10, The diameter of the pile body formed by cutting 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 that of the first reinforcement body 110 diameter.

Wherein, the operation mode of the rotary spraying hardening includes: as shown in Fig. 7-10, the rotary spraying drill pipe 10 adopts the method of lifting while rotating and spraying, from the bottom of the guide hole 20 upwards, at the first One nozzle 11 rotates and sprays to a certain height, and then opens the second nozzle 12 for selective spraying.

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 are set in the way that the high-pressure air 2 packs the high-pressure water 1, that is, the high-pressure air 2 is located at the periphery of the spray range of the high-pressure water 1 Located in the center of the spray range of high-pressure air 2, it forms high-pressure water and high-pressure air similar to "water-in-air", which can cut and stir through the water-in-air method.

The first nozzle 11 in the upper section sprays ultra-high pressure water 1 and air jet fluid to guide and pre-cut the soil to form certain pre-formed holes 30, and the second nozzle 12 in the lower section sprays ultra-high pressure hardening material 3 to pre-form holes 30 Continue to expand the cutting soil, and at the same time, under the action of air lift, the generated sediment and slurry can be smoothly removed upward; the injection pressure of ultra-high pressure hardening material 3 is higher, so that it can be reinforced faster, but ultra-high pressure hardening should also be avoided Excessive injection pressure of the material 3 affects the structure of the adjacent overlapping second reinforcing body 120 .

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 distance between the upper and lower nozzles; the distance between the upper and lower nozzles of the drill pipe can be adjusted as required.

It can be understood that in the embodiment of the present application, the diameter of the guide hole 20 has a certain matching relationship with the parameters of the first nozzle 11 and the second nozzle 12, and the parameters of the first nozzle 11 and the second nozzle 12 are directly related to the reinforcement. The diameter of the pile and the height of the reinforcement.

Optionally, the distance between the first nozzle 11 and the second nozzle 12 on the rotary jet drill pipe 10 is 1.2m-1.4m; it should be noted that the distance between the first nozzle 11 and the second nozzle 12 The larger it is, as shown in FIG. 12 , it means that the water and air that the first nozzle 11 cuts off the soil have less disturbance to the reinforcement slurry 5 mixed with the high-pressure hardening material 3 and the cement slurry 4 sprayed out by the second nozzle 12 . If the first nozzle 11 and the second nozzle 12 are very close, as shown in FIG. 13 , the generated turbulence and pressure will take away most of the reinforcement slurry 5 . The setting of the distance between the first nozzle 11 and the second nozzle 12 can also avoid the too long depth of the ineffective introduction hole 21, which wastes the cost and time of the introduction hole 20; It is also not conducive to filling the invalid lead hole 21, so the mixture of soil and water may still be in the invalid lead hole 21, causing the danger of reinforcing the structure. After the research in this application, the setting of 1.2m to 1.4m can combine the factors of the above aspects to achieve the optimization effect.

Optionally, when the first reinforcement 110 is formed, the pressure of the high-pressure water 1 of the first nozzle 11 is 25MPa-37MPa, the flow rate is 150L/min-200L/min; the pressure of the high-pressure air 2 is 0.75MPa ～1.25MPa, 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, the flow rate is 115L/min～135L/min; The spraying radius of the first nozzle 11 is 85%-90% of the radius of the first reinforcing body 110; the spraying radius of the second nozzle 12 is 10%-15% of the radius of the first reinforcing body 110.

When forming the second reinforcement 120, the pressure of the high-pressure water 1 of the first nozzle 11 is 35MPa-45MPa, the flow rate is 180L/min-220L/min; the pressure of the high-pressure air 2 is 1.05MPa-1.75MPa, 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 of the first nozzle 11 The radius is 85%-90% of the radius of the second reinforcement 120 ; the spray radius of the second nozzle 12 is 10%-15% of the radius of the second reinforcement 120 .

The specific parameter settings are shown in Table 2 below.

Table 2

In the embodiment of the present application, by controlling the return passage of the guide hole 20 and the rotary grouting drill pipe 10, enough space can be reserved, and during the process of ultra-high pressure reinforced rotary grouting, the groove wall can be effectively prevented from collapsing and blocking the rotary grouting In the case of the drill pipe 10, the time for dealing with failures is saved and the reinforcement efficiency is improved.

In the embodiment of the present application, by controlling the size of the pilot hole 20, it is beneficial for the first ultra-high pressure air 2 and ultra-high pressure water 1 to cut to form a larger cylinder, reducing the soil near the drill pipe, reducing energy loss, and making the super The energy of high-pressure air 2 and ultra-high-pressure water 1 is effectively utilized, the spraying is farther, and the cutting range is larger, which creates favorable conditions for the second re-cutting of ultra-high-pressure hardened material 3 .

Another important improvement point in this application lies in the matching of pre-cutting and secondary cutting ranges. First, because the upper part of the high-pressure air with 2 packs of high-pressure water 1 carries out the cutting of the pile body, the reinforced body cut by 2 packs of high-pressure air with 1 high-pressure water needs 85-90% of the pile diameter, and the remaining 10-15% of the pile diameter of the reinforced body is determined by The high-pressure slurry of the lower nozzle performs the cutting. Second, during the entire reinforcement process, the high-pressure grout of the lower nozzle plays the role of expanding the pile body and further spraying the grout, stirring the lower mixed liquid evenly, so that the strength of the reinforcement is more uniform, and more hardened materials can be left A slurry of 3 increases the displacement rate. Under the condition of applying the same hardening material 3, a reinforced body with larger pile diameter, better reinforcement quality, smaller permeability coefficient and greater reinforcement strength can be obtained.

It can be understood that, in the embodiment of the present application, the first reinforcement 110 and the second reinforcement 120 are both cylindrical, and the swirling angle of the first nozzle 11 and the second nozzle 12 can be 360°, in different In the embodiment, according to the requirements of the design, any angle can be sprayed; the pressures of the ultra-high pressure air 2, ultra-high pressure water 1, and ultra-high pressure hardening material 3 slurry rotary jet grouting can be adjusted according to needs. In addition, the above process parameters are only for experimental reference, and work together with the properties of the soil and the depth of reinforcement. 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 in sandy soil, and the diameter of the pile in cohesive soil is small.

Example

S1: The site is leveled, and steel casings of a certain depth are buried on the site corresponding to each of the above-mentioned introduction holes, for example, 3-4m deep steel casings are buried, in order to prevent the introduction holes 20 pre-formed holes 30 cement slurry 4 and reinforcement The returned slurry of the soil body is discharged everywhere, and a temporary collection pit 40 for the returned slurry is excavated at the top of the reinforced body.

At the position of the temporary collection pit 40, a mud discharge device 50 is provided to absorb the cement slurry 4, which can control the internal pressure. If the pressure is too high, the cement slurry 4 can be actively pumped to reduce the internal pressure, so that the ultra-high pressure hardened material and air Under the same spraying pressure, the spray fluid can make the reinforcement more uniform and the reinforcement quality better

S2: 20 drilling rigs for large-diameter lead holes are in place, supplemented by high-quality mud protection walls, and 30 pre-formed holes are drilled with 60cm drill bits, and the verticality is measured every 10m. The hole 20 is 1.4 m deeper than the second reinforcement 120 .

S3: The ultra-high pressure rotary grouting equipment is in place, the level of the equipment is precisely adjusted, and it is aligned with the center of the designed pile, and then the rotary grouting drill pipe 10 is lowered with the assistance of a truck crane.

S4: After the rotary jet drill pipe 10 is put in place, start the background air compressor to deliver high-pressure air 2, high-pressure water pump 1 to deliver high-pressure water 1, turn on the first nozzle 11 in the upper section of the rotary jet drill pipe 10, and the ultra-high pressure rotary jet equipment rotates the drill Rod, the first nozzle 11 rotates 360° with the drill pipe and sprays the mixed flow of ultra-high pressure water 1 and high-pressure air 2 to pre-cut the original soil body in the upper section, and at the same time, the rotary jet drill pipe 10 is slowly lifted according to the setting, so as to continuously pre-cut upward Soil, form cement slurry 4 in the cylindrical space, to achieve the purpose of expanding the pile body and cutting the soil for the first time;

S5: At the same time, part of the cement slurry 4 is discharged upward through the slurry return channel under the combined action of the gas lift and the continuously injected high-pressure water 1 , and is sucked away by the mud discharge device 50 .

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

S7: After the rotary grouting drill pipe 10 is lifted to cut 1.4m of the undisturbed soil in the upper section through the first nozzle 11, the second nozzle 12 in the lower section is opened immediately, and the second nozzle 12 rotates with the drill pipe 360° 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 undisturbed soil again to form a space cylinder that meets the pile diameter requirements. At the same time, under the action of jetting, the ultra-high pressure hardening material 3 slurry and cement slurry 4 are fully stirred and mixed to form ultra-high pressure. Hardening material 3 and cement slurry 4 reinforcement slurry 5 .

S8: While the second nozzle 12 is rotating and spraying, the upper part of the cement slurry 4 will be discharged under the combined action of air lift and continuous injection of high-pressure water 1, high-pressure air 2, and ultra-high-pressure hardening material 3, using a reliable slurry return channel. Surplus cement slurry 4 is sucked away by mud discharge equipment 50 .

S9: According to the setting, slowly lift the rotary grouting drill pipe 10 according to the set step distance and rotate and spray 360° until it is reinforced to the top of the designed pile, stop the first nozzle 11 and the second nozzle 12 from spraying grouting, and remove the first nozzle 11 and the second nozzle 12. The second reinforced body 120 is used for the next construction.

In the embodiment of the present application, the first reinforcement body 110 and the second reinforcement body 120 at the corresponding positions are formed by the same rotary spraying drill pipe 10 through one-time rotary spray hardening; the first reinforcement body 110 and the second reinforcement body 110 The technical parameters of the jet hardening of the reinforcing body 120 are different. After the jet hardening of the first reinforcing body 110 and the second reinforcing body 120 is completed, the jet drilling drill pipe 10 is removed together for the next construction.

The method also includes:

The rotary grouting drill pipe 10 is disassembled, and after the initial setting of the reinforcement slurry, grouting is performed again in the introduction hole 20 to form secondary filling.

S10: After 1 day, before the grout hardening in the 20 channels of the pilot hole, after the chemical reaction with the ultra-high pressure hardening material 3 liquid + soil particle mixture for initial setting, in order to ensure the quality of the deep reinforcement pile at the top of the pile, the pile top shall be subjected to secondary Ordinary grouting is used for secondary filling from the pile head to ensure the quality of the pile head. It can be understood that one or two ordinary grouting methods can be used for the first reinforcement body 110 and the second reinforcement body 120 that are simultaneously jet-hardened, and the present application is not limited thereto.

It is to be understood that the terms "length", "width", "top", "bottom", "front", "rear", "left", "right", "vertical", "horizontal", "top" , "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device Or elements must have a certain orientation, be constructed and operate in a certain orientation, and thus should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terminology used herein is only for the purpose of describing a specific implementation, and is not intended to limit the present invention. Terms such as "disposed" appearing herein may mean that one component is directly attached to another component or that one component is attached to another component through an intermediary. Features described herein in one embodiment may be applied to another embodiment alone or in combination with other features, unless the feature is not applicable in that other embodiment or stated otherwise.

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 illustration and description, and are not intended to limit the present invention within the scope of the described embodiments. Those skilled in the art can understand that more variations and modifications can be made according to the teaching of the present invention, and these variations and modifications all fall within the scope of protection claimed by the present invention.

Claims (10)

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/or a second reinforcement area, the first reinforcement area A reinforcement area includes a plurality of first reinforcements arranged in an array, and two adjacent first reinforcements are arranged tangentially; the second reinforcement area includes a plurality of second reinforcements arranged in an array, and two adjacent second reinforcements exist Partially overlapping; each of the first reinforcements is formed by one reinforcement, and each of the second reinforcements is formed by one reinforcement; When the central reinforced area includes the first reinforced area and the second reinforced area, the first reinforced area and the second reinforced area are stacked, and the first reinforced area is arranged on the second reinforced area. In the upper layer of the reinforcement area, the axis of the first reinforcement body and the second reinforcement body at the corresponding position are coincident, and the first reinforcement body and the second reinforcement body are coaxially constructed and reinforced at one time. 2. The bridge foundation reinforcement structure according to claim 1, wherein the wall reinforcement area includes a first edge reinforcement set on the same layer as the first reinforcement body and a first edge reinforcement body on the same layer as the second reinforcement body For the second edge reinforcement provided, two adjacent second edge reinforcements partially overlap; the axis of the first edge reinforcement coincides with the axis of the second edge reinforcement at the corresponding position. 3. The bridge foundation reinforcement structure according to claim 2, wherein the height of the first reinforcement body is greater than the height of the second reinforcement body, and the diameter of the first reinforcement body is smaller than that of the second reinforcement body The diameter of the solid, the diameter of the first edge reinforcement is the same as that of the first reinforcement, the diameter of the second edge reinforcement is the same as that of the second reinforcement; two adjacent first edge reinforcements The center-to-center distance of the two adjacent first reinforcement bodies is smaller than the center-to-center distance of the two adjacent second reinforcement bodies, and the center-to-center distance between the two adjacent second edge reinforcement bodies is smaller than the center-to-center distance of the two adjacent second reinforcement bodies. 4. The bridge foundation reinforcement structure according to claim 1, characterized in that, The height of the first reinforcement is 20m-27m, and the diameter is 1.5m-2m; The second reinforcing body has a height of 4m-8m and a diameter of 2.4m-3m; The depth of the bottom surface of the first reinforcement is 40m-51m; The depth of the bottom surface of the second reinforcement is 48m-55m. 5. A construction method for a bridge foundation reinforcement structure, characterized in that, for forming the bridge foundation reinforcement structure as claimed in any one of claims 1-4, the construction is carried out using a jet-jet drill pipe, and the jet-jet drill pipe 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 includes: forming guide holes at the axial positions of the first reinforcement and/or the second reinforcement; forming a plurality of first reinforcements and/or a plurality of second reinforcements arranged in an array through rotary spraying drill rods inserted into the guide hole and hardened by rotary spraying; When the central reinforcement area includes the first reinforcement area and the second reinforcement area, the same rotary spraying drill pipe is inserted into the same guide hole for coaxial construction, and the rotary spraying hardening is performed once Reinforcing the first reinforcement body and the second reinforcement body; Wherein, the manner of said rotary spray hardening specifically includes: Pre-cutting the soil body by 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 second nozzle rotates and sprays the high-pressure hardening material to cut the soil twice, so as to expand the pile body again and form a solid slurry of hardening material and cement slurry. 6. The construction method of bridge foundation reinforcement structure according to claim 5, is characterized in that, before forming described lead hole, described method also comprises: A steel casing of a certain depth is buried on the site corresponding to each of the introduction holes, and a collection pit for collecting the cement slurry and the reinforcement slurry is opened at each of the introduction hole locations. 7. the construction method of bridge foundation reinforcement structure according to claim 5, is characterized in that, the diameter of described guide hole is 40cm～65cm; The diameter of described rotary grouting drill rod is 10cm～20cm; Described guide hole and The distance between the jet grouting drill pipes to form the return slurry channel is 15cm-20cm; The method for forming a hole includes: Drilling through the drill bit supplemented by mud retaining walls; Perpendicularity measurement is performed at intervals of fixed heights to ensure that the verticality deviation of the pilot hole is ≤1/300. 8. The construction method of the bridge foundation reinforcement structure according to claim 5, wherein the first nozzle is close to the upper surface of the foundation, the second nozzle is far away from the upper surface of the foundation, and the first nozzle and the second nozzle are The two nozzles are arranged on opposite sides of the jet-jet drill pipe, and the diameter of the pile body formed by the pre-cutting of the first nozzle is smaller than the diameter of the pile body formed by the secondary cutting of the second nozzle; The operation mode of the rotary spray hardening includes: the rotary spray drill rod adopts the method of lifting while rotating and spraying, from the bottom of the guide hole upwards, and then opens the second nozzle after the first nozzle rotates and sprays to a certain height Perform selective injection. 9. The construction method of bridge foundation reinforcement structure according to claim 5, characterized in that, the distance between the first nozzle and the second nozzle on the jet-jet drill pipe is 1.2m-1.4m; When forming the second reinforced body, the pressure of the high-pressure water in 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, the flow rate is 120L/min～155L/min; the spray radius of the first nozzle is the radius of the second reinforced body 85%-90% of that; the spray radius of the second nozzle is 10%-15% of the radius of the second reinforcement; When forming the first reinforced body, the pressure of the high-pressure water in 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 spray radius of the first nozzle is 85%～90% of the radius of the first reinforcement; The spraying radius of the second nozzle is 10%-15% of the radius of the first reinforcing body. 10. The construction method of bridge foundation reinforcement structure according to claim 5, is characterized in that, described method also comprises: The rotary grouting drill pipe is removed, and after the initial setting of the reinforcement slurry, grouting is performed again in the introduction hole to form secondary filling.

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