Road and bridge integrated system pavement anti-cracking treatment method

Abstract

The application discloses a pavement anti-cracking treatment method of a road-bridge fusion system, which comprises the following steps: arranging an L-shaped lateral limiting steel plate at a joint of a soil subgrade and a widening bridge at a expansion joint; embedding a bottom plate of the L-shaped lateral limiting steel plate in a water-stable broken stone layer of the soil subgrade, and arranging the top of the L-shaped lateral limiting steel plate at a distance of 1 cm from an asphalt pavement layer; arranging a widening sealing glue between the L-shaped lateral limiting steel plate and a plate of the widening bridge; and arranging an epoxy asphalt mixture between a web plate of the L-shaped lateral limiting steel plate and the soil subgrade, and embedding the epoxy asphalt mixture under an asphalt concrete paving layer of the soil subgrade. The application is based on the innovative concept of "rigid isolation and lateral constraint", utilizes the deformation limiting of the L-shaped lateral limiting steel plate and the excellent performance of the epoxy asphalt mixture in terms of deformation resistance and high adhesion, effectively solves the pavement longitudinal crack problem at the joint of the expansion joint of the plate bridge and the soil subgrade in the reconstruction and expansion project of the bridge structure such as the pile-plate road, the pile-plate retaining wall subgrade and the half-mountain plate bridge, reduces the pavement maintenance, and improves the driving comfort.

Description

Technical Field

[0001] This invention belongs to the field of engineering construction, especially the field of reconstruction and expansion projects, and specifically relates to a method for preventing and treating pavement cracks in a road-bridge integrated system. This invention can effectively solve the problem of longitudinal cracks in the pavement at the junction of bridge expansion joints and subgrade in reconstruction and expansion projects, reduce pavement maintenance, improve driving comfort, and form a key technology for road-bridge integrated roads. Background Technology

[0002] Current highway construction faces several challenges: ① a severe shortage of land and soil; ② increased costs associated with land acquisition and soil extraction; and ③ rising costs for soil treatment and reclamation. These factors severely impact the economic viability and applicability of traditional highway construction methods that primarily utilize land and soil.

[0003] Adopting the concept of road-bridge integration and an industrialized model, at a large-scale and serialized level, enables the construction of highways with less soil, no soil, high efficiency, and low cost, which is an inevitable choice to meet current challenges and respond to green development. Currently, the difficulties in land acquisition and large amounts of fill during road reconstruction and expansion can be roughly summarized into three road-bridge integrated system solutions: Solution 1 uses pile-slab retaining wall roadbeds; Solution 2 uses semi-mountain, semi-bridge roadbeds; and Solution 3 uses pile-slab road structures.

[0004] However, practice has shown that the road-bridge integration system still faces technical challenges in reconstruction and expansion projects, namely: longitudinal cracks appear in the pavement layer at the road-bridge junction, especially at expansion joints where cracking is more severe, requiring frequent pavement maintenance. This is because the overlapping beams exert longitudinal tension on the pavement layer at the road-bridge junction due to temperature and vehicle braking. Furthermore, at expansion joints, where there is no lateral restraint, the asphalt layer easily deforms laterally towards the bridge expansion joint under localized vehicle wheel loads. Under tension and lateral deformation, cracks easily form at the expansion joint, affecting structural durability, comfort, and safety. Therefore, there is an urgent need to develop a pavement crack prevention and treatment method for the road-bridge integration system to solve the pavement cracking problem and form a true road-bridge integration technology. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preventing and treating road surface cracks in a road-bridge integrated system.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A method for preventing cracking in the pavement of a road-bridge integrated system involves setting an L-shaped lateral limiting steel plate at the expansion joint of the earthen subgrade and the widened bridge. The bottom plate of the L-shaped lateral limiting steel plate is embedded in the water-stabilized crushed stone layer of the earthen subgrade, and its top is 1 cm away from the asphalt pavement layer.

[0008] A jointing sealant is installed between the L-shaped lateral limiting steel plate and the jointed bridge plate;

[0009] An epoxy asphalt mixture is installed between the web of the L-shaped lateral limiting steel plate and the subgrade, and is buried under the asphalt concrete pavement layer of the subgrade.

[0010] Further technology of the present invention:

[0011] Preferably, the L-shaped lateral limiting steel plate is made of Q235 or higher grade steel, with an elastic modulus of E, a longitudinal length of m along the bridge, a web height of h, a bottom plate width of n, and a steel plate thickness of t. These parameters can be calculated using the following steps:

[0012] (1) Determine the length of the L-shaped lateral restraint steel plate along the longitudinal direction of the bridge as m, m:

[0013] The L-shaped lateral limiting steel plate should cover the range of the bridge expansion joint: m≥b+0.4(m); b is the gap at the beam end;

[0014] (2) Determine the web height h, m of the L-shaped lateral limiting steel plate:

[0015] h≥0.5m;

[0016] (3) Determine the width n, m of the L-shaped lateral limiting steel plate base:

[0017] The width of the base plate is n = max(0.3, 0.7h);

[0018] (4) Calculate the active earth pressure P at the top A and bottom B points of the web of the L-shaped lateral restraint steel plate under vehicle wheel load. A P B Here, the influence of the asphalt layer of the subgrade is ignored, and for safety reasons, the restraining effect of the bridge and road on the L-shaped lateral restraining steel plate outside the gap at the end of the slab bridge is ignored. That is, the calculation is simplified to regard the L-shaped lateral restraining steel plate in the gap at the end of the slab bridge as a cantilever beam with one end anchored and the other end simply supported under lateral compression.

[0019] Active earth pressure coefficient of crushed stone in subgrade: The internal friction angle of the gravel layer is taken as 45° to 50°.

[0020] Active earth pressure at point A on the web of the L-shaped lateral limiting steel plate: P A =K a q L ;

[0021] Active earth pressure at point B on the web of the L-shaped lateral restraint steel plate: P B =K a (γh+q L ), where γ is the average unit weight of the cement-stabilized crushed stone layer in the soil subgrade;

[0022] The value corresponding to the rear wheel load of the car wheel is:

[0023] (5) Calculate the resultant lateral earth pressure on the web of the L-shaped lateral restraint steel plate and its distance from point B:

[0024] Resultant lateral active earth pressure on the web of the L-shaped lateral restraint steel plate:

[0025] E a Distance C from point B:

[0026] (6) Calculate the thickness t, mm, of the L-shaped lateral limiting steel plate;

[0027] Lateral bending moment of inertia of L-shaped lateral limiting steel plate:

[0028] To control the lateral deformation of the asphalt layer at point A to no more than 1.5 mm, the lateral deformation at point A is: Elastic modulus E = 2.06 x 10⁻⁶ 5 MPa, t takes the smallest integer value.

[0029] Preferably, the epoxy asphalt mixture includes coarse aggregate, fine aggregate, mineral powder and epoxy asphalt. The amount of raw materials is determined according to the principle of volume composition. The coarse aggregate forms the skeleton structure. After the epoxy asphalt wraps the coarse aggregate, it forms voids. The voids are filled by epoxy mortar formed by fine aggregate, mineral powder and epoxy asphalt. The key sieve holes of the epoxy mortar are controlled.

[0030] Preferably, the coarse aggregate includes two grades: 3-5mm and 5-10mm. The skeleton structure formed by the coarse aggregate is determined using a software model, and the optimal blending ratio of the two grades of coarse aggregate under the best compaction state is carried out according to the following steps:

[0031] (1) Use particle flow software to establish a discrete element calculation model of a certain size;

[0032] (2) According to different mixing ratios, particles are randomly added to the model step by step;

[0033] (3) Set the gravitational acceleration to make the aggregate sink and reach stability, so as to stabilize the average unbalanced force;

[0034] (4) Set a measuring circle along the center of the model inside the mixture to determine the void ratio of the mixture;

[0035] (5) The relationship between the porosity variation under different coarse aggregate blending ratios is fitted by Guass peak to find the coarse aggregate blending ratio when the porosity is at its minimum.

[0036] Preferably, the amount of coarse aggregate in the epoxy asphalt mixture is determined by mixing the coarse aggregate according to a certain ratio, conducting a Marshall compaction test, compacting 100 times on one side, measuring its compacted density and void ratio after compaction, and calculating the density per m³ using the following formula. 3 Coarse aggregate dosage for epoxy asphalt mixtures:

[0037]

[0038] P c =1000×(1-VC)×ρ c

[0039] In the formula: ρ c —Synthetic gradation density, g / cm³ 3 ;ρ sc — Compacted density of the synthetic gradation, g / cm³ 3 ;

[0040] VC – Porosity of coarse aggregate after compaction, %; P c ——1m 3 Coarse aggregate dosage for epoxy asphalt mixture, kg.

[0041] Preferably, after the epoxy asphalt coats the coarse aggregate, it forms voids. Based on the principle of having the same specific surface area, the coarse aggregate is equivalent to a sphere. The epoxy asphalt coats the sphere with a certain asphalt film and expands the coarse aggregate. The radius of the sphere and the expanded volume are calculated according to the following formula:

[0042]

[0043]

[0044] Where: SA—specific surface area, m 2 / kg; ρ—density of aggregate, g / cm³ 3 R—Equivalent sphere diameter of the aggregate, mm;

[0045] P a1 — Volume ratio of epoxy asphalt coated with coarse aggregate, %; u — thickness of asphalt film, μm;

[0046] P c1 —Proportion of 5-10mm coarse aggregate, %; P c2 —Proportion of 3-5mm coarse aggregate, %;

[0047] D1—Equivalent sphere diameter of 5-10mm coarse aggregate, mm; D2—Equivalent sphere diameter of 3-5mm coarse aggregate, mm;

[0048] Preferably, after the epoxy mortar fills the voids formed by the epoxy asphalt coating the coarse aggregate and expanding part of its volume, the remaining void ratio after filling is the epoxy asphalt mixture void ratio, calculated according to the following formula per m³. 3 Epoxy mortar dosage in epoxy asphalt mixture:

[0049]

[0050] In the formula: P j ——1m 3 Epoxy mortar dosage in epoxy asphalt mixture, kg; ρ j —Density of epoxy mortar, g / cm³ 3 VV—Porosity of epoxy asphalt mixture, %.

[0051] Preferably, in the epoxy mortar formed by the fine aggregate, mineral powder, and epoxy asphalt, the epoxy asphalt coats the mineral powder and fine aggregate with a certain asphalt film thickness. The amount of mineral powder, fine aggregate, and epoxy asphalt in 1 m³ of epoxy asphalt mixture is determined according to the following formula:

[0052] G+g+P a2 =P j

[0053] P a2 =u×(G×SA) G +g×SA g )×ρ a

[0054] Where: G——1m 3 Epoxy asphalt mixture fine aggregate dosage, kg; g—1m 3 Mineral powder dosage in epoxy asphalt mixture, kg; P a2 ——1m 3 The amount of asphalt used in epoxy mortar in epoxy asphalt mixtures, in kg; ρ a —Density of epoxy asphalt, g / cm³ 3 ;

[0055] SA G —Specific surface area of ​​fine aggregate, m 2 / kg; SA g —Specific surface area of ​​mineral powder, m 2 / kg.

[0056] Preferably, the key sieve aperture control of the epoxy mortar is based on a 0.075mm passing rate through the key sieve aperture to control the proportion of mineral powder and fine aggregate in the mortar. The proportion of mineral powder and fine aggregate is determined according to the following formula:

[0057]

[0058] 100 = G1 + g1

[0059] In the formula: S 0.075 —The sieve passing rate (%) of epoxy mortar with a 0.075mm sieve opening;

[0060] —Passing rate of fine aggregate through a 0.075mm sieve, %;

[0061] —Passage rate of mineral powder through a 0.075mm sieve, %;

[0062] G1—Proportion of fine aggregate in epoxy mortar, %;

[0063] g1 — Proportion of mineral powder in epoxy mortar, %.

[0064] Overall, the technical solution provided by this invention has the following advantages compared with the prior art:

[0065] 1. This invention can promote significant land-saving, soil-saving, and carbon-reducing effects in highway engineering construction. The road-bridge integration system is an ideal structure for achieving low-soil, soil-free, efficient, and low-cost construction in highway reconstruction and expansion projects. This invention effectively solves the long-standing, major, and difficult problem of longitudinal cracks in new soil subgrades and pavements in road-bridge integration systems, reduces pavement maintenance, improves driving comfort, forms a key technology for road-bridge integration, and effectively promotes the application of road-bridge integration systems in domestic and international reconstruction and expansion projects. It has significant economic and social benefits and broad application prospects.

[0066] 2. The epoxy asphalt mixture provided by this invention, firstly, utilizes a volume-controlled design where coarse aggregate forms a skeleton, enhancing the mixture's strength. Epoxy mortar is then fully filled into the voids in the coarse aggregate skeleton, increasing the contact area between the epoxy asphalt mixture and the steel plate, thus ensuring a strong bond between them. Secondly, combining asphalt film-forming theory and volume-filling methods, the coating asphalt and filling asphalt are calculated separately. From a functional perspective, the amount of epoxy asphalt added is precisely calculated to improve the performance of the epoxy asphalt mixture, more effectively fulfilling its bonding and load-bearing functions.

[0067] 3. The road-bridge integrated system structure of the present invention has reliable stress performance and good durability. Epoxy asphalt mixture is set between the L-shaped lateral limiting steel plate and the earthen roadbed pavement structure. This material has good bonding and load-bearing properties, effectively improving the pavement stiffness at the road-bridge connection, while ensuring a firm connection between the L-shaped limiting steel plate and the earthen roadbed, ensuring the stability of the entire device and the durability of the structure.

[0068] 4. Simple and clear treatment method: The present invention has a simple and reasonable structure, is convenient to construct, and has strong versatility. The treatment method is simple and easy to operate. It is applicable to reconstruction and expansion projects using road-bridge integration system. In addition to highway reconstruction and expansion projects, it can be widely used in other engineering construction fields and has broad application prospects. Attached Figure Description

[0069] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0070] Figure 1 This is a schematic cross-sectional view of the overall structure of the present invention;

[0071] Figure 2 for Figure 1 Schematic diagram of AA section;

[0072] Figure 3 for Figure 1 Schematic diagram of the cross-section of BB;

[0073] Figure 4 Elevation view of the L-shaped lateral limiting steel plate;

[0074] Figure 5 This is a cross-sectional view of the L-shaped lateral restraint steel plate;

[0075] Figure 6 A schematic diagram for calculating the active earth pressure on an L-shaped lateral restraint steel plate;

[0076] Figure 7 To determine the internal porosity of the mixture;

[0077] In the diagram, 1-L-shaped lateral limiting steel plate, 2-epoxy asphalt mixture, 3-cast-in-place transition section, 4-width sealing adhesive. Detailed Implementation

[0078] To make the technical means, creative features, achieved objectives, and effects of this invention easier to understand, the invention is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this invention and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments described herein without creative effort are all within the protection scope of this invention.

[0079] like Figure 1-6 This invention provides a road-bridge integrated system for pavement crack prevention and treatment, the method of which is as follows:

[0080] L-shaped lateral limiting steel plate 1 is set at the joint between the earth subgrade and the widened bridge at the expansion joint. Its bottom plate is embedded in the water-stabilized crushed stone layer of the earth subgrade and is connected to the earth subgrade through epoxy asphalt mixture. Its top should be 1cm away from the asphalt pavement layer.

[0081] Epoxy asphalt mixture 2 is set between the web of the L-shaped lateral limiting steel plate and the subgrade, and is buried under the asphalt concrete pavement layer of the subgrade. It consists of coarse aggregate, fine aggregate, mineral powder and epoxy asphalt. The amount of raw materials is determined according to the principle of volume composition. The coarse aggregate forms the skeleton structure. After the epoxy asphalt wraps the coarse aggregate, it forms voids, which are filled by epoxy mortar formed by fine aggregate, mineral powder and epoxy asphalt. The key sieve holes of the epoxy mortar are controlled.

[0082] The cast-in-place transition section 3 is located between the lap beam of the widened bridge and the earth subgrade. The steel bars inside the lap beam extend into it and it is composed of C40 concrete.

[0083] The 4-layer sealant is applied between the L-shaped lateral limiting steel plate and the overlapping beam.

[0084] The L-shaped lateral limiting steel plate 1 can be designed with reference to the following example:

[0085] A road-bridge integrated reconstruction and expansion project applied the pavement crack prevention treatment method of this invention. The widened bridge is a pile-slab structure with a continuous length of 42m, using elastic concrete seamless expansion joints with a beam end gap b = 40mm; the L-shaped lateral limiting steel plate is made of Q235 steel with an elastic modulus E = 2.06 x 10⁻⁶. 5 MPa; Average unit weight of the crushed stone layer in the subgrade γ = 22 kN / m 3 internal friction angle Take 45°.

[0086] (1) Determine the length m (m) of the L-shaped lateral limiting steel plate:

[0087] m≥0.04+0.4=0.44m, m is taken as 0.5m.

[0088] (2) Determine the web height h (m) of the L-shaped lateral limiting steel plate:

[0089] h = 0.7m ≥ 0.5m.

[0090] (3) Determine the width n (m) of the bottom plate of the L-shaped lateral limiting steel plate:

[0091] n=max(0.3,0.7x0.7)=0.49m.

[0092] (4) Calculate the active earth pressure P at the top A and bottom B points of the web of the L-shaped lateral restraint steel plate under vehicle wheel load. A P B .

[0093] The vehicle wheel load is taken as the corresponding value for the rear wheels according to the "General Design Specifications for Highway Bridges and Culverts".

[0094] Active earth pressure coefficient of crushed stone in subgrade:

[0095] Active earth pressure at point A on the web of the L-shaped lateral limiting steel plate: P A =0.172 x 583.3 = 100.3 kPa;

[0096] Active earth pressure at point B on the web of the L-shaped lateral restraint steel plate:

[0097] P B =0.172x(22x0.7+583.3)=103.0KPa;

[0098] (5) Calculate the resultant lateral earth pressure on the web of the L-shaped lateral restraint steel plate and its distance from point B:

[0099] Resultant of lateral active earth pressure:

[0100] E a Distance C from point B:

[0101] (6) Calculate the thickness t of the L-shaped lateral restraint steel plate:

[0102] Lateral bending moment of inertia of L-shaped lateral limiting steel plate:

[0103] To ensure the asphalt pavement layer does not crack, the lateral deformation of the asphalt layer at point A is controlled to not exceed 1.5 mm. The lateral deformation at point A is as follows:

[0104]

[0105] t≥19.9mm, t is taken as 20mm.

[0106] The epoxy asphalt mixture 2 has a length L = 0.5 + 0.1 = 0.6 m along the route and a transverse width B = 0.49 + 0.1 = 0.59 m.

[0107] The epoxy asphalt mixture 2 is set between the web of the L-shaped lateral limiting steel plate 1 and the subgrade, and is buried under the asphalt concrete pavement layer of the subgrade. It includes coarse aggregate, fine aggregate, mineral powder and epoxy asphalt. The amount of raw materials is determined according to the principle of volume composition. The coarse aggregate forms the skeleton structure. After the epoxy asphalt wraps the coarse aggregate, it forms voids, which are filled by epoxy mortar formed by fine aggregate, mineral powder and epoxy asphalt. The key sieve holes of the epoxy mortar are controlled.

[0108] The epoxy asphalt mixture 2 described above can be designed with reference to the following case:

[0109] The results of the raw material screening are shown below:

[0110] Table 1. Aggregate Screening Results

[0111]

[0112] A two-dimensional discrete element method (DEM) model was established using particle flow software. The aggregate thickness was set to 1 mm, the total weight of all aggregates was set to 100 kg, the nominal maximum particle size was 9.5 mm, and the model boundary was 250 mm × 500 mm. Particles with a particle size of 5–10 mm to 3–5 mm were randomly added to the model in stages using particle flow software at ratios of 0:100, 20:80, 40:60, 50:50, 60:40, 80:20, and 100:0. Gravitational acceleration was set to ensure all aggregate particles reached equilibrium under gravity. The average unbalanced force in the particle system was monitored to stabilize. A measurement circle with a radius of 100 mm was set along the center of the model to determine the internal porosity of the mixture. Figure 7 As shown, the porosity variation relationship under different coarse aggregate blending ratios is fitted using Guass peak:

[0113] According to the above fitting results, the porosity is lowest when the ratio of 5-10 mm to 3-5 mm is 55:45. Coarse aggregate was prepared according to the above ratio, and the Marshall compaction method was used to compact it 100 times on one side. The porosity of the mixture was measured, and the porosity of 1 m³ was determined. 3 Coarse aggregate quality in epoxy asphalt mixtures:

[0114]

[0115]

[0116] The two coarse aggregates are equivalent to spheres of a single particle size with the same specific surface area according to the following formula:

[0117]

[0118] The calculated equivalent particle size D1 for 5–10 mm is 2.41 mm, and the equivalent particle size D2 for 3–5 mm is 1.76 mm.

[0119] Based on the spatial composition principle of epoxy asphalt mixture and the film-forming characteristics of asphalt, the thickness of the asphalt film is taken as 10 μm, and the porosity of the mixture is controlled at 3%. The amount of epoxy asphalt mortar is determined according to the following formula.

[0120]

[0121] P′ a1 =Pa1 ×ρ a =61.91kg

[0122]

[0123] The proportion of new asphalt is controlled according to the asphalt film-forming theory. Asphalt coats the aggregate surface with a certain film thickness, and the specific surface area SA of fine aggregate and mineral powder is calculated. G =9.06m 2 / kg, SA g =30.83m 2 / kg, asphalt film thickness is 10µm, asphalt density is 1020kg / m³ 3 Calculate the asphalt content. The amount of epoxy asphalt mainly includes the asphalt used to coat the coarse aggregate and the asphalt in the epoxy asphalt mortar.

[0124] G+g+P a2 =532.4

[0125]

[0126] The proportion of mineral powder and fine aggregate in epoxy mortar was controlled by setting the key sieve aperture of 0.075mm to 15%.

[0127]

[0128] 100 = g1 + G1

[0129] The calculated ratio of mineral powder to fine aggregate in epoxy mortar is 70:30.

[0130] Calculations show that 1m 3 In epoxy asphalt mixture, 1215.5 kg of 5-10 mm coarse aggregate, 994.5 kg of 3-5 mm coarse aggregate, 238 kg of 0-3 mm fine aggregate, and 102 kg of mineral powder are used. The asphalt content is the sum of the asphalt coating the coarse aggregate and the asphalt in the epoxy mortar, which is 254.3 kg.

[0131] The aforementioned widening sealing colloid material 4 is mainly composed of fibers and modified asphalt. The ratio of fibers to asphalt is controlled at 100:5 to 100:8.

[0132] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0133] In this invention, unless explicitly specified and limited, features are intertwined and do not necessarily exist independently. The above description includes the basic principles, main features, and advantages of this invention. Those skilled in the art should understand that this invention is not limited to the above embodiments; the embodiments and description are merely preferred examples and not intended to limit the invention or be the only option. Within the spirit and scope of the invention, it can be further modified and optimized. All improvements and optimizations to this invention fall within the scope of the claims, which are defined by the appended claims and their equivalents.

Claims

1. A method for preventing road surface cracking in a road-bridge integrated system, characterized in that: An L-shaped lateral limiting steel plate is installed at the expansion joint of the earth roadbed and the widened bridge. The bottom plate of the L-shaped lateral limiting steel plate is embedded in the water-stabilized crushed stone layer of the earth roadbed, and its top is 1 cm away from the asphalt pavement layer. A jointing sealant is installed between the L-shaped lateral limiting steel plate and the jointed bridge plate; An epoxy asphalt mixture is installed between the web of the L-shaped lateral limiting steel plate and the subgrade, and is buried under the asphalt concrete pavement layer of the subgrade. The L-shaped lateral limiting steel plate is made of Q235 or higher grade steel, and the elastic modulus of the steel plate is [missing value]. The longitudinal length of the bridge is Web height Base plate width The thickness of the steel plate is taken as The above parameters can be calculated using the following steps: (1) Determine the length of the L-shaped lateral limiting steel plate along the longitudinal direction of the bridge as follows: m: The L-shaped lateral limiting steel plate should cover the area of ​​the bridge expansion joint: b represents the gap at the beam end; (2) Determine the web height of the L-shaped lateral limiting steel plate m: ； (3) Determine the width of the L-shaped lateral limiting steel plate bottom plate m: Base plate width ; (4) Calculate the active earth pressure at the top A and bottom B of the web of the L-shaped lateral restraint steel plate under vehicle wheel load. , Here, the influence of the asphalt layer of the subgrade is ignored, and for safety reasons, the restraining effect of the bridge and road on the L-shaped lateral restraining steel plate outside the gap at the end of the slab bridge is ignored. That is, the calculation is simplified to regard the L-shaped lateral restraining steel plate in the gap at the end of the slab bridge as a statically indeterminate beam with one end anchored and the other end simply supported under lateral compression. Active earth pressure coefficient of crushed stone in subgrade: , The internal friction angle of the gravel layer is taken as 45°~50°; Active earth pressure at point A on the web of the L-shaped lateral restraint steel plate: ; Active earth pressure at point B on the web of the L-shaped lateral restraint steel plate: , The average unit weight of the cement-stabilized crushed stone layer for the subgrade; The value corresponding to the rear wheel load of the car wheel is: ; (5) Calculate the resultant lateral earth pressure on the web of the L-shaped lateral restraint steel plate and its distance from point B: Resultant lateral active earth pressure on the web of the L-shaped lateral restraint steel plate: ; Distance C from point B: ; (6) Calculate the thickness of the L-shaped lateral limiting steel plate mm; Lateral bending moment of inertia of L-shaped lateral limiting steel plate: ; To control the lateral deformation of the asphalt layer at point A to no more than 1.5 mm, the lateral deformation at point A is: Elastic modulus , Take the smallest integer value.

2. The method for preventing road surface cracking in a road-bridge integrated system according to claim 1, characterized in that: Epoxy asphalt mixtures include coarse aggregate, fine aggregate, mineral powder, and epoxy asphalt. The amount of raw materials is determined according to the principle of volume composition. Coarse aggregate forms the skeleton structure. After the epoxy asphalt wraps the coarse aggregate, it forms voids. The voids are filled by epoxy mortar formed by fine aggregate, mineral powder, and epoxy asphalt. The key sieve holes of the epoxy mortar are controlled.

3. The method for preventing road surface cracking in a road-bridge integrated system according to claim 2, characterized in that: The coarse aggregate includes two grades: 3-5mm and 5-10mm. The optimal blending ratio of these two grades of coarse aggregate, under the best compaction condition, is determined using a software model, following these steps: (1) Establish a discrete element calculation model of a certain size using granular flow software; (2) According to different mixing ratios, particles are randomly added to the model step by step; (3) Set the gravitational acceleration to make the aggregate sink and reach stability, so as to control the average unbalanced force to tend to stabilize; (4) A measuring circle is set along the center of the model inside the mixture to determine the porosity of the mixture; (5) Use Guass peak to fit the relationship between the porosity changes under different coarse aggregate blending ratios, so as to find the coarse aggregate blending ratio when the porosity is at its minimum.

4. The method for preventing road surface cracking in a road-bridge integrated system according to claim 3, characterized in that: The amount of coarse aggregate in the epoxy asphalt mixture is determined by mixing the coarse aggregate according to the specified ratio, conducting a Marshall compaction test, compacting 100 times on one side, measuring the compacted density and void ratio after compaction, and calculating the perm³ using the following formula. 3 Coarse aggregate dosage for epoxy asphalt mixtures: ； ； In the formula: —Synthetic gradation density, g / cm³ 3 ; — Compacted density of the synthetic gradation, g / cm³ 3 ; —Porosity of coarse aggregate after compaction, % ——1m 3 Coarse aggregate dosage for epoxy asphalt mixture, kg.

5. The method for preventing road surface cracking in a road-bridge integrated system according to claim 4, characterized in that: The epoxy asphalt coating of coarse aggregate creates voids. Based on the principle of equal specific surface area, the coarse aggregate is considered equivalent to a sphere. The epoxy asphalt wraps around the sphere with a certain asphalt film, thus expanding the coarse aggregate. The radius of the sphere and the expanded volume are calculated using the following formula: ； ； In the formula: Specific surface area, m 2 / kg; —Density of aggregate, g / cm³ 3 ; —Equivalent sphere diameter of the aggregate, mm; —The volume ratio of epoxy asphalt coated with coarse aggregate after expansion, % —Asphalt film thickness, in μm; —Proportion of 5-10mm coarse aggregate, % --Proportion of 3-5mm coarse aggregate, % —Equivalent sphere diameter of 5-10mm coarse aggregate, mm; —Equivalent sphere diameter of 3-5mm coarse aggregate, mm.

6. The method for preventing road surface cracking in a road-bridge integrated system according to claim 5, characterized in that: After the epoxy mortar fills the voids formed by the epoxy asphalt coating the coarse aggregate and expands part of the volume, the remaining void ratio after filling is the epoxy asphalt mixture void ratio, calculated according to the following formula per m³. 3 Epoxy mortar dosage in epoxy asphalt mixture: ； In the formula: ——1m 3 Epoxy mortar dosage in epoxy asphalt mixture, kg; —Density of epoxy mortar, g / cm³ 3 ; —Porosity of epoxy asphalt mixture,%.

7. A method for preventing road surface cracking in a road-bridge integrated system according to claim 6, characterized in that: The epoxy mortar formed by the fine aggregate, mineral powder, and epoxy asphalt, in which the epoxy asphalt coats the mineral powder and fine aggregate with a certain asphalt film thickness, is determined according to the following formula: The amount of mineral powder, fine aggregate, and epoxy asphalt in 1m3 of epoxy asphalt mixture is determined by the following formula: ； ； In the formula: ——1m 3 Epoxy asphalt mixture fine aggregate dosage, kg; ——1m 3 Mineral powder dosage in epoxy asphalt mixture, kg; ——1m 3 The amount of asphalt used in epoxy mortar in epoxy asphalt mixtures, in kg; —Density of epoxy asphalt, g / cm³ 3 ; —Specific surface area of ​​fine aggregate, m 2 / kg; —Specific surface area of ​​mineral powder, m 2 / kg.

8. A method for preventing pavement cracking in a road-bridge integrated system according to claim 7, characterized in that, The key sieve aperture control of the epoxy mortar is based on the 0.075mm passing rate of the key sieve aperture to control the blending ratio of mineral powder and fine aggregate in the mortar. The blending ratio of mineral powder and fine aggregate is determined according to the following formula: ； ； In the formula: —The required sieve passing rate for epoxy mortar with a 0.075mm aperture, % —Passing rate of fine aggregate through a 0.075mm sieve, % —Passing rate of mineral powder through a 0.075mm sieve, % —The proportion of fine aggregate in epoxy mortar, % —Proportion of mineral powder in epoxy mortar,%.

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