Lattice type pavement structure hole arrangement and void area grouting repair method
By reserving scientifically designed grouting holes and utilizing the diffusion characteristics of expandable polymers, the problem of dense grouting pipe arrangement in grid-type pavement structures was solved, achieving efficient and low-cost repair of voided areas and improving construction efficiency and repair results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-04-10
AI Technical Summary
The dense arrangement of grouting pipes in existing grid-type pavement structures leads to poor grouting effect, making it difficult to accurately control the grout outlet position and affecting the repair effect of voided areas.
By utilizing the diffusion characteristics of expandable polymers and reserving scientifically designed grouting holes, the actual void area is determined through a ground probe. Appropriate grouting holes are selected for grouting, and L-shaped and extended grouting pipe designs are used to reduce construction difficulty and cost.
It improves the accuracy and efficiency of grouting repair, reduces construction difficulty and cost, minimizes traffic disruption, and achieves efficient repair of voided areas.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of road repair technology and relates to a method for repairing voided areas in a grid-type road structure with hole arrangement. Background Technology
[0002] With rapid economic development, my country has constructed numerous road projects in permafrost regions. However, due to temperature variations, frost heave and thaw settlement are frequent problems on highways in these areas, seriously affecting traffic safety. Currently, increasing the thermal resistance of the roadbed, improving heat dissipation methods, and enhancing the stability of the roadbed fill are common methods for preventing uneven deformation of the roadbed. Masonry slope protection, deepening side ditches, and adding drainage ditches are the main methods for preventing frost heave and frost heave. However, these methods are still insufficient to completely cure the problems in permafrost regions. Therefore, the repair and maintenance of road and railway projects in permafrost regions remains a major challenge.
[0003] Lattice-type pavement structures are a type of pavement structure that has been applied in recent years (e.g., patent number CN116791419A). They consist of a carriageway slab and a steel lattice. The top surface of the steel lattice connects to the bottom surface of the carriageway slab, and the bottom surface connects to the base course. The steel lattice contains longitudinal and transverse supports. This type of lattice-type pavement structure, from top to bottom, consists of an asphalt surface layer, a concrete slab, a steel lattice, a concrete leveling layer, and the subgrade. Using this new pavement structure can solve the problem of existing pavement structures easily undergoing random deformation when the base course experiences random settlement, thus adversely affecting vehicle traffic. However, during use, subgrade settlement is inevitable, creating voids between the concrete leveling layer and the subgrade structure, thereby affecting structural safety. Although this patent incorporates a grouting repair system (horizontal delivery pipes and vertical grouting pipes) in the structure, the dense arrangement of these grouting pipes, with each horizontal pipe connecting to numerous vertical grout outlet pipes, makes it difficult to precisely control the grout outlet position, thus affecting the grouting effect and hindering the leveling layer's ability to repair subgrade settlement. Summary of the Invention
[0004] This invention addresses the technical problem of the dense arrangement of grouting pipes in lattice pavement structures affecting grouting effectiveness. It provides a method for hole layout and grouting repair of voided areas in lattice pavement structures. By utilizing the diffusion characteristics of expandable polymers, grouting holes are pre-reserved to cope with different situations, making the hole layout more scientific, reducing costs, and decreasing the difficulty and on-site workload of drilling holes in steel panels after voids occur, thereby improving work efficiency.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] This invention provides a method for grouting repair of voided areas in a lattice pavement structure, comprising the following steps:
[0007] 1) Based on the diffusion radius of the expandable polymer grout The boundary of the predicted void region is obtained;
[0008] 2) Based on the predicted boundary of the void area, reserve the first and second grouting holes on the subgrade of the left and right halves of the area to be paved with the grid-like pavement structure; install L-shaped grouting pipes on the first grouting holes, with the vertical section of the L-shaped grouting pipe close to the bottom plate of the pavement structure and a sealing plate installed at the bottom, and the horizontal section threadedly connected to an extension grouting pipe, the end of which is aligned with the shoulder, and a one-way valve is installed on the extension grouting pipe; the second grouting hole is located on the shoulder side, with a horizontal distance of 1.8 meters from the first grouting hole. The second grouting hole extends upwards to the upper part of the panel of the lattice pavement structure;
[0009] 3) The actual voided area is probed using a ground-penetrating device to determine its boundary;
[0010] 4) Based on the boundary of the actual de-emptying area, find the predicted de-emptying area that overlaps with the actual de-emptying area;
[0011] 5) Based on the offset distance between the predicted boundary of the voided area and the actual boundary of the voided area. The decision is made to select either the first or second grouting hole in the predicted voided area for grouting.
[0012] In the above technical solution, the diameter of the first grouting hole and the second grouting hole is 12~20 mm.
[0013] In the above technical solution, the characteristic of expanding polymer (such as two-component expanded polyurethane foam) grouting is that it relies on its own expansion characteristics for diffusion. The expansion characteristics are related to density, and the density is affected by the amount of grout injected. Therefore, the formula for calculating the diffusion radius r of the expanding polymer grout is as follows:
[0014] Formula (1),
[0015] in: To predict the thickness of the voided region; To predict the grouting volume, , and These represent the predicted length and width of the voided region, respectively. For polymer grouting density, It is a constant related to temperature.
[0016] The value ranges from 1.1 to 2.0; the lower the temperature, the lower the value. The higher the value, the better when the temperature is below 0℃. Use a value of 1.6~2.0; when the temperature is above 0℃, Take 1.1-1.5. The construction of road sections to be paved in permafrost areas is greatly related to the local temperature. For example, in the Qinghai-Tibet Plateau region, the temperature is too low from October to February of the following year to make construction difficult. Therefore, the average minimum temperature from March to September shall be used as the basis.
[0017] In addition, considering the structural characteristics of bridge pavement, in order to ensure the effect of subsequent grouting repair, the compressive strength of the polymer after grouting is required to exceed 10 MPa. Therefore, the polymer grouting density can be determined according to the relationship between temperature, density and strength at the site.
[0018] In the above technical solution, the formula for calculating the longitudinal spacing of the first grouting holes along the road travel direction is as follows:
[0019] Formula (2),
[0020] Where: l is the longitudinal spacing of the first grouting holes along the road travel direction; The diffusion radius of the expandable polymer grouting fluid; This is the subgrade coefficient.
[0021] The value ranges from 1.8 to 3. When geological conditions are poor and frost heave and thaw settlement are severe, Take 1.8~2; when geological conditions are moderate and frost heave and thaw settlement are slight, Take 2~2.5; when the geological conditions are good and frost heave and thaw settlement diseases have basically not occurred, Take 2.5~3.
[0022] In the above technical solution, step 4) specifically includes: if Then, the first grouting hole on the predicted voided area is selected for grouting; if If r is selected, then the second grouting hole on the predicted voided area is selected for grouting.
[0023] The above technical solution also includes the following steps: based on the boundary of the predicted void area, a third grouting hole is reserved on the subgrade near the centerline of the grid pavement structure to be paved. The third grouting hole extends upward to the upper part of the panel of the grid pavement structure. The distance between the third grouting hole and the centerline is 0.5 m. The third grouting hole is arranged at intervals on both sides of the centerline. The longitudinal spacing of the third grouting hole and the first grouting hole along the driving direction of the road is the same. The third grouting hole and the first grouting hole are arranged in a quincunx pattern. When a void occurs near the centerline, grouting is performed through the third grouting hole.
[0024] In the above technical solution, the diameter of the third grouting hole is 12~20 mm.
[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0026] This invention utilizes the diffusion characteristics of expandable polymers to pre-define grouting holes for different situations, reducing the difficulty and on-site workload of drilling holes in steel panels after voids occur later. Furthermore, this grouting hole design method is more scientific, reducing the cost of pre-setting too many grouting holes, and offers advantages such as quick construction, simple steps, budget savings, and no disruption to traffic.
[0027] This invention fully considers the characteristics of road surface structure and the randomness of road surface voids, and provides comprehensive coverage of the voids that occur. It also significantly reduces construction costs, lowers the difficulty of drilling for grouting repairs, improves construction efficiency, and reduces traffic disruption. Attached Figure Description
[0028] Figure 1 This is a schematic diagram showing the location of the first grouting hole in this invention.
[0029] Figure 2 This is a schematic diagram showing the location of the second grouting hole in this invention.
[0030] Figure 3 This represents the positional relationship between the actual vacancy area and the predicted vacancy area. Detailed Implementation
[0031] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the test methods in the following embodiments are conventional methods.
[0032] This invention discloses a method for grouting repair of voided areas in a lattice-type pavement structure, comprising the following steps:
[0033] 1) Based on the diffusion radius of the expandable polymer grout (See Formula 1) to obtain the boundary of the predicted void region;
[0034] 2) Based on the predicted boundary of the void area, reserve the first and second grouting holes on the subgrade of the left and right halves of the grid-type pavement structure of the section to be paved; the diameter of the first and second grouting holes is 12~20 mm, and the calculation formula for the longitudinal spacing of the first grouting holes along the driving direction of the road is given in Formula 2; install L-shaped grouting pipes on the first grouting holes, with the vertical section of the L-shaped grouting pipe close to the bottom plate of the pavement structure and a sealing plate installed at the bottom, and the horizontal section threadedly connected to the extension grouting pipe, the end of the extension grouting pipe aligned with the shoulder, and a one-way valve installed on the extension grouting pipe; the second grouting hole is located on the shoulder side, with a horizontal distance of 1.8 km from the first grouting hole. The second grouting hole extends upwards to the upper part of the panel of the lattice pavement structure;
[0035] 3) The actual voided area is probed using a ground-penetrating device to determine its boundary;
[0036] 4) Based on the boundary of the actual de-emptying area, find the predicted de-emptying area that overlaps with the actual de-emptying area;
[0037] 5) Based on the offset distance between the predicted boundary of the voided area and the actual boundary of the voided area. The decision is made to determine whether to perform grouting from the first or second grouting hole in the predicted voided area. Specifically: if Then, the first grouting hole on the predicted voided area is selected for grouting; if If so, then the second grouting hole on the predicted voided area is selected for grouting.
[0038] In addition, based on the predicted boundary of the void area, a third grouting hole is reserved on the subgrade near the centerline of the grid pavement structure to be paved. The diameter of the third grouting hole is 12~20 mm. The third grouting hole extends upward to the upper part of the panel of the grid pavement structure. The distance between the third grouting hole and the centerline is 0.5 m. The third grouting holes are arranged at intervals on both sides of the centerline. The longitudinal spacing of the third grouting hole and the first grouting hole along the driving direction of the road is the same. The third grouting hole and the first grouting hole are arranged in a quincunx pattern. When a void occurs near the centerline, grouting is performed through the third grouting hole.
[0039] Example 1
[0040] like Figure 1 As shown, the first grouting hole is located on the subgrade of the grid-like pavement structure to be paved. An L-shaped grouting pipe is installed on the first grouting hole. The vertical section of the L-shaped grouting pipe is close to the bottom plate of the pavement structure and a sealing plate is installed at the bottom. The sealing plate is installed at the bottom of the L-shaped grouting pipe in advance to prevent subgrade soil from entering and clogging the grouting pipe during paving. The horizontal section of the L-shaped grouting pipe is threadedly connected to an extension grouting pipe. The end of the extension grouting pipe is aligned with the shoulder, and a one-way valve is installed on the extension grouting pipe to prevent external soil or other debris from entering and clogging the grouting pipe. The extension grouting pipe and the L-shaped grouting pipe are connected by threads, which facilitates replacement if deformation or blockage occurs after paving.
[0041] like Figure 2 As shown, the second grouting hole is located near the shoulder side, with a horizontal distance of 1.8r from the first grouting hole. The second grouting hole extends upwards to the upper part of the panel of the lattice pavement structure. The second grouting hole does not have a pre-fabricated grouting pipe; the grouting hole is only pre-reserved at the upper part of the panel. At the same time, no longitudinal or transverse supports are installed at this location to prevent the subsequent drilling from being too difficult.
[0042] During road paving, the locations of the first and second grouting holes are marked in advance on the concrete subbase. Then, when pouring concrete, a wooden plug with the same diameter as the grouting hole is placed at each grouting hole. After the concrete subbase has cured, the wooden plug in the first grouting hole is removed. An L-shaped grouting pipe and an extension grouting pipe are connected to the first grouting hole, and the road structure is then paved. When the target thickness of the slab is approached, the wooden plug in the second grouting hole is removed, and foam with the same diameter as the hole is placed at the second grouting hole beforehand. The slab is then paved.
[0043] Example 2
[0044] Based on the predicted boundary of the void area, a third grouting hole is reserved on the subgrade near the centerline of the grid pavement structure to be paved. The third grouting hole extends upward to the upper part of the panel of the grid pavement structure. The distance between the third grouting hole and the centerline is 0.5 m. The third grouting hole is arranged at intervals on both sides of the centerline. The longitudinal spacing of the third grouting hole and the first grouting hole along the driving direction of the road is the same. The third grouting hole and the first grouting hole are arranged in a quincunx pattern.
[0045] To ensure economic efficiency, the first and second grouting holes are pre-installed only in the left and right halves of the road. However, there is still a possibility of voids forming near the centerline. Since the centerline is far from the shoulder, installing L-shaped grouting pipes is difficult and costly. Therefore, a third grouting hole can be pre-installed on the upper part of the slab, without longitudinal or transverse supports to prevent difficulties in subsequent drilling. During pavement construction, the location of the third grouting hole is marked in advance on the concrete subbase. Then, when pouring concrete, a wooden plug with the same diameter as the grouting hole is placed at each hole. The bridge-type pavement structure is then laid. When approaching the target thickness of the slab, the wooden plug in the second grouting hole is removed, and foam with the same diameter as the hole is placed at the second grouting hole before continuing slab construction.
[0046] Example 3
[0047] like Figure 3 As shown, due to the uncertainty of the voided area, the diffusion area of the reserved first grouting hole (i.e., the predicted voided area) cannot completely overlap with the actual voided area. Therefore, the pre-set first grouting hole may not be able to completely repair the actual voided area. Furthermore, the polymer reaction is too rapid, making it difficult to effectively fill the actual voided area completely. Therefore, after determining the boundary of the actual voided area using a ground-penetrating device, it is necessary to determine the offset distance between the boundary of the predicted voided area and the boundary of the actual voided area. Diffusion radius of expandable polymer grout The relationship between the two factors determines whether to perform grouting in the predicted voided area using the first or second grouting hole. If the predicted void area is reached, the first grouting hole on the predicted void area is selected for grouting. This involves connecting the grouting gun to the corresponding extension grouting pipe, and then performing polymer grouting based on temperature and other conditions. Grouting is stopped when the designed grouting volume is reached (1.2-1.5 times). If so, select the second grouting hole on the predicted void area for grouting. That is, directly use an impact drill to vertically drill a hole at the foam of the second grouting hole, then install the grouting pipe at that location and carry out grouting. The grouting volume is determined through the above steps.
[0048] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.
Claims
1. A lattice pavement structure hole and void area grouting repair method, characterized in that, The method comprises the following steps: 1) according to the diffusion radius of the expanding polymer grouting liquid to obtain the boundary of the predicted void area; 2) According to the boundary of the predicted void area, reserve first and second grouting holes on the roadbed of the left and right half areas of the grid pavement structure to be paved; install an L-shaped grouting pipe on the first grouting hole, the vertical section of the L-shaped grouting pipe is close to the lower bottom plate of the pavement structure and installs a closing piece at the bottom, the horizontal section is connected with an extended grouting pipe by a thread, the end of the extended grouting pipe is aligned with the road shoulder, and a one-way valve is arranged on the extended grouting pipe; the second grouting hole is close to one side of the road shoulder, and the horizontal distance from the first grouting hole is 1.8 , the second grouting hole extends upward to the upper part of the panel of the grid pavement structure; 3) detecting the actual void area by the ground penetrating device to determine the boundary of the actual void area; 4) finding the predicted void area which overlaps with the actual void area according to the boundary of the actual void area; 5) the distance of the deviation of the boundary of the predicted void area from the boundary of the actual void area determining whether to select the first grouting hole or the second grouting hole on the predicted void area for grouting.
2. The lattice pavement structure hole and void area grouting repair method according to claim 1, characterized in that, The first grouting hole and the second grouting hole have a diameter of 12-20 mm.
3. The lattice pavement structure hole and void area grouting repair method according to claim 1, characterized in that, The diffusion radius of the intumescent polymer grouting liquid The calculation formula is as follows: ， wherein: is the thickness of the void area to be predicted; is the grouting amount to be predicted, , and are the length and width of the void area to be predicted, respectively, is the polymer grouting density, is a temperature-dependent constant.
4. The lattice pavement structure hole and void area grouting repair method according to claim 1 or 3, characterized in that, The calculation formula of the longitudinal row spacing of the first grouting hole along the driving direction of the pavement is as follows: ， Wherein: l is the longitudinal spacing of the first grouting hole along the driving direction of the road surface; is the diffusion radius of the intumescent polymer grouting fluid; is the ground coefficient.
5. The lattice pavement structure hole and void area grouting repair method according to claim 1, characterized in that, Step 4) specifically includes: if , the first grouting hole on the predicted emptying area is selected for grouting; if , the second grouting hole on the predicted emptying area is selected for grouting.
6. The lattice pavement structure hole and void area grouting repair method according to claim 1, characterized in that, The method further comprises the following steps: According to the boundary of the predicted void area, a third grouting hole is reserved on the roadbed near the center line of the to-be-paved lattice pavement structure, the third grouting hole extends upward to the upper part of the panel of the lattice pavement structure, the distance between the third grouting hole and the center line is 0.5 m, the third grouting hole is arranged at intervals along the two sides of the center line, the longitudinal row spacing of the third grouting hole along the driving direction of the pavement is the same as that of the first grouting hole, and the third grouting hole and the first grouting hole are arranged in a plum blossom shape; when void occurs near the center line, grouting is performed through the third grouting hole.
7. The lattice pavement structure hole and void area grouting repair method according to claim 1, characterized in that, The third grouting hole has a diameter of 12-20 mm.