Construction method for widening roads in coastal areas

Abstract

The invention provides a widening construction method for roads in a coastal area, and belongs to the field of road construction. The method comprises the following steps: establishing a numerical model based on stratum parameters, the width of a road and the to-be-widened degree, and simulating a plurality of reinforcement parameter groups through the numerical model to obtain settlement data and horizontal displacement data of the numerical model reinforced by each reinforcement parameter group, and then determining the displacement data and the minimum reinforcement parameter group as a target reinforcement parameter group, and broadening the road according to the target reinforcement parameter group. In this way, the reinforcing mode with small settlement and horizontal displacement can be determined in a model simulation mode so as to be flexibly applied to broadening construction of various roads, and the effect of improving the flexibility of the method is achieved.

Description

Technical Field

[0001] This application relates to the field of road construction, and in particular to a method for widening roads in coastal areas. Background Technology

[0002] Road widening construction is a type of construction used to widen existing roads.

[0003] In one road widening construction method, some parameters of the road to be widened are first obtained, and then the road to be widened is widened based on these parameters and historical construction methods.

[0004] However, the above method is difficult to determine the appropriate construction method based on various parameters of the road to be widened, resulting in poor flexibility of the method. Summary of the Invention

[0005] This application provides a method for widening roads in coastal areas, which solves the problem of poor flexibility in related road widening construction methods. The technical solution is as follows: According to a first aspect of this application, a method for widening roads in coastal areas is provided, the method comprising: Obtain the geological parameters of the area to be constructed where the road is located, the width of the road, and the width to be widened. Among the geological parameters, the area to be constructed includes a soft soil layer and a sand layer arranged sequentially downwards along the ground surface. A numerical model is established based on the geological parameters, the width of the road, and the width to be expanded. The numerical model includes the geological strata and the existing road and the road to be expanded located on the geological strata. The existing road and the road to be expanded are connected. The road to be expanded includes a first embankment and a first pavement structure located on the first embankment. A geogrid is installed in the first embankment, and a pile foundation is installed in the geological strata below the first embankment. Multiple reinforcement parameter sets are obtained, each of which includes the pile length of the plain concrete pile in the pile foundation and the parameters of the geogrid in the first embankment, and the parameters in any two reinforcement parameter sets are not all the same. An equivalent uniformly distributed live load greater than a preset value is applied to the first pavement structure in the numerical model and to the original road. The plurality of reinforcement parameter sets are loaded into the numerical model respectively to obtain settlement data and horizontal displacement data of the numerical model corresponding to each reinforcement parameter set. The settlement data includes settlement values ​​at multiple locations of the numerical model, and the horizontal displacement data includes horizontal displacement values ​​at multiple locations of the numerical model. The reinforcement parameter group with the smallest displacement data sum among the plurality of reinforcement parameter groups is determined as the target reinforcement parameter group, wherein the displacement data sum is the sum of the settlement data and the horizontal displacement data of the numerical model corresponding to the reinforcement parameter group; The road is widened using the target reinforcement parameter set.

[0006] Optionally, determining the reinforcement parameter set with the smallest sum of displacement data among the plurality of reinforcement parameter sets as the target reinforcement parameter set includes: Obtain the maximum settlement value from the settlement data of any one of the multiple reinforcement parameter groups; When the maximum settlement value is less than or equal to the settlement threshold, the average settlement value of the settlement values ​​at multiple locations in the target area of ​​the numerical model in any set of reinforcement parameters is obtained, where the target area is the area in the numerical model where the settlement value is greater than or equal to 4 cm. Obtain the maximum horizontal displacement value from the horizontal displacement data of any one of the plurality of reinforcement parameter groups; When the maximum horizontal displacement value is less than or equal to the horizontal displacement threshold, the average horizontal displacement value of multiple locations in the target region of the numerical model in any of the reinforcement parameter groups is obtained; The sum of the average settlement value and the average horizontal displacement value is determined as the displacement data of any set of reinforcement parameters.

[0007] Optionally, before loading the plurality of hardening parameter sets into the numerical model respectively, the method further includes: When the plain concrete piles and geogrid in the pile foundation are not set in the numerical model, the unreinforced settlement data and unreinforced horizontal displacement data of the numerical model are obtained. Based on the unreinforced settlement data and the unreinforced horizontal displacement data, the unreinforced displacement data of the numerical model are obtained. Before determining the reinforcement parameter set with the smallest displacement data among the plurality of reinforcement parameter sets as the target reinforcement parameter set, the method further includes: Determine whether the sum of the displacement data of the reinforcement parameter group with the smallest displacement data among the plurality of reinforcement parameter groups is less than the sum of the displacement data of the unreinforced group; When the sum of the displacement data is less than the sum of the unreinforced displacement data, the step of determining the reinforcement parameter group with the smallest sum of displacement data among the plurality of reinforcement parameter groups as the target reinforcement parameter group is performed. When the displacement data is not less than the unreinforced displacement data, adjust the plurality of reinforcement parameter groups and perform the steps of loading the plurality of reinforcement parameter groups onto the numerical model respectively.

[0008] Optionally, in the numerical model, the original road includes a second embankment and a second pavement structure located on the second embankment. The second pavement structure is connected to the first pavement structure, and the second embankment is connected to the first embankment. The strata include a soft soil layer and a sand layer arranged sequentially downwards along the ground surface. The first embankment and the second embankment are located on the soft soil layer, and the pile foundation is located in the soft soil layer below the first embankment.

[0009] Optionally, in the numerical model, the first pavement structure and the second pavement structure are bound together, and the second pavement structure is the master surface and the first pavement structure is the slave surface. The soft soil layer is a Mohr-Coulomb elastoplastic model, the sand layer is a linear elastic model, the first embankment and the second embankment both include four stacked embankment layers, the four embankment layers are in an overconsolidated state, and the first embankment and the second embankment are both linear elastic models. The plain concrete piles and the geogrid are both made of elastic materials.

[0010] Optionally, applying an equivalent uniformly distributed live load greater than a preset value to the first pavement structure in the numerical model and the original road includes: The first embankment and the first pavement structure in the numerical model are hidden; Gravity is applied to the second pavement structure, the second embankment, and the stratum, and stress balance is achieved. From the direction upward from the stratum, the four embankment layers and the first pavement structure are activated respectively, and gravity is applied to the first pavement structure and the first embankment. An equivalent uniformly distributed live load greater than the preset value of 11 kPa is applied to the first pavement structure and the second pavement structure.

[0011] Optionally, the four embankment layers are a first embankment layer, a second embankment layer, a third embankment layer, and a fourth embankment layer arranged sequentially in a direction away from the stratum. The acquisition of multiple reinforcement parameter sets includes: The four undetermined pile lengths of the plain concrete pile are obtained, and the four undetermined pile lengths are 7 meters, 9 meters, 11 meters and 13 meters respectively; Four configuration structures for the geogrid are obtained, and the four configuration structures are as follows: The geogrid is laid at the bottom of the first embankment layer; The geogrid is laid at the bottom of the first embankment layer and the second embankment layer respectively; The geogrid is laid at the bottom of the first embankment layer, the second embankment layer and the third embankment layer respectively; The geogrid is laid at the bottom of the first embankment layer, the second embankment layer, the third embankment layer and the fourth embankment layer respectively; Based on the four undetermined pile lengths, the four configuration structures of the geogrid, and the orthogonal test method, the multiple sets of reinforcement parameters were obtained.

[0012] Optionally, the elastic modulus of the first pavement structure and the second pavement structure is 1470 MPa, the Poisson's ratio is 0.3, and the bulk density is 2400 kN per cubic meter; The first embankment has an elastic modulus of 4 MPa, a Poisson's ratio of 0.45, and a bulk density of 1750 kN per cubic meter. The second embankment has an elastic modulus of 25 MPa, a Poisson's ratio of 0.25, and a bulk density of 1950 kN / m³.

[0013] Optionally, the numerical model is a half-width model that includes the road and half of the structure of the expanded road; In the numerical model, the width of the first road surface structure is 8 meters, the width of the second road surface structure is 16 meters, the thickness of the first embankment and the first road surface structure is 5 meters, the thickness of the soft soil layer is 11 meters, the thickness of the sand layer is 34 meters, and the width of the stratum is 50 meters.

[0014] Optionally, the pile foundation includes a plurality of plain concrete piles, the pile spacing of the plurality of plain concrete piles is two meters, and the diameter of each plain concrete pile is 0.8 meters.

[0015] The beneficial effects of the technical solutions provided in this application include at least the following: The coastal road widening construction method provided in this application establishes a numerical model based on geological parameters, road width, and the desired widening width. This numerical model simulates multiple reinforcement parameter sets to obtain settlement and horizontal displacement data for each set after reinforcement. The reinforcement parameter set with the smallest displacement data is then selected as the target reinforcement parameter set, and the road is widened using this target set. This method allows for the determination of reinforcement methods with minimal settlement and horizontal displacement through model simulation, enabling flexible application in various road widening constructions and enhancing the method's flexibility. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a method for widening a road in a coastal area, as shown in an embodiment of this application. Figure 2 This is a flowchart illustrating another method for widening a road in a coastal area, as shown in an embodiment of this application. Figure 3 A numerical model dimension diagram provided for an embodiment of this application; Figure 4 for Figure 3 The diagram shows the model building process of the numerical model. Figure 5 This is a vertical displacement cloud map provided in an embodiment of this application; Figure 6 This is a vertical displacement curve provided in an embodiment of this application; Figure 7 This is another vertical displacement cloud map provided in the embodiments of this application; Figure 8 This is a vertical displacement curve provided in an embodiment of this application; Figure 9 This is another vertical displacement cloud map provided in the embodiments of this application; Figure 10 This is a vertical displacement curve provided in an embodiment of this application; Figure 11 This is a horizontal displacement curve of a soft soil layer when different layers of geogrid are laid, provided as an embodiment of this application.

[0018] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0020] Figure 1 This application illustrates a method flowchart for widening roads in coastal areas, which includes the following steps: Step 101: Obtain the geological parameters of the area to be constructed, the width of the road, and the width to be widened. Among the geological parameters, the area to be constructed includes soft soil layers and sand layers arranged sequentially downwards along the ground surface.

[0021] Step 102: Establish a numerical model based on the stratum parameters, the width of the road, and the width to be expanded. The numerical model includes the stratum and the existing road and the road to be expanded located on the stratum. The existing road and the road to be expanded are connected. The road to be expanded includes a first embankment and a first pavement structure located on the first embankment. Geogrids are installed in the first embankment, and pile foundations are installed in the stratum below the first embankment.

[0022] Step 103: Obtain multiple reinforcement parameter groups. Each reinforcement parameter group includes the pile length of the plain concrete pile in the pile foundation and the parameters of the geogrid in the first embankment. The parameters in any two reinforcement parameter groups are not all the same.

[0023] Step 104: Apply an equivalent uniformly distributed live load greater than the preset value to the first pavement structure of the numerical model and the original road.

[0024] Step 105: Load multiple reinforcement parameter sets into the numerical model to obtain settlement data and horizontal displacement data of the numerical model corresponding to each reinforcement parameter set. The settlement data includes settlement values ​​at multiple locations of the numerical model, and the horizontal displacement data includes horizontal displacement values ​​at multiple locations of the numerical model.

[0025] Step 106: Determine the reinforcement parameter group with the smallest displacement data sum among multiple reinforcement parameter groups as the target reinforcement parameter group. The displacement data sum is the sum of the settlement data and horizontal displacement data of the numerical model corresponding to the reinforcement parameter group.

[0026] Step 107: Widen the road using the target reinforcement parameter set.

[0027] In summary, the coastal road widening construction method provided in this application establishes a numerical model based on geological parameters, road width, and the desired widening width. This numerical model simulates multiple reinforcement parameter sets to obtain settlement and horizontal displacement data for each set after reinforcement. The reinforcement parameter set with the smallest displacement data is then selected as the target reinforcement parameter set, and the road is widened using this target set. This method allows for the determination of reinforcement methods with smaller settlement and horizontal displacement through model simulation, enabling flexible application in various road widening constructions and enhancing the method's flexibility.

[0028] Figure 2 This is a flowchart illustrating another method for widening roads in coastal areas, as shown in an embodiment of this application. The method includes the following steps: Step 201: Obtain the geological parameters of the area to be constructed, the width of the road, and the width to be widened. Among the geological parameters, the area to be constructed includes soft soil layers and sand layers arranged sequentially downwards along the ground surface.

[0029] The method provided in this application is a method involving foundation treatment and reinforcement, excavation, and filling.

[0030] The sand layers can be divided into fine sand, medium sand, and coarse sand layers. The fineness modulus of the coarse sand is 3.7–3.1, and the average particle size is greater than 0.5 mm. The fineness modulus of the medium sand is 3.0–2.3, and the average particle size is 0.5–0.35 mm. The fineness modulus of the fine sand is 2.2–1.6, and the average particle size is 0.35–0.25 mm. The stratigraphic parameters can be obtained from the exploration and design documents of the area to be constructed; the specific method of obtaining these parameters is not limited in this embodiment.

[0031] Step 202: Establish a numerical model based on geological parameters, road width, and the width to be widened.

[0032] The numerical model includes the geological strata and the existing and expanded roads located on the strata. The existing and expanded roads are connected. The expanded road includes a first embankment and a first pavement structure located on the first embankment. Geogrids are installed in the first embankment, and pile foundations, including multiple plain concrete piles, are installed in the strata below the first embankment. The existing road includes a second embankment and a second pavement structure located on the second embankment. The second pavement structure is connected to the first pavement structure. The second embankment is connected to the first embankment. The geological strata include soft soil layers and sand layers arranged downwards from the surface. The first and second embankments are located on the soft soil layer, and the pile foundations are located in the soft soil layer below the first embankment.

[0033] Since roads are usually symmetrical, in this embodiment of the application, the numerical model is a half-width model that includes the road and half of the structure of the extended road. For example, the original road is 32 m wide, and the half-width in the numerical model is 16 m. Figure 3 A numerical model dimension diagram provided for an embodiment of this application, such as Figure 3 As shown, the parameters (in meters) in the numerical model established in this application are as follows: the width of the first pavement structure is 8 meters, the width of the second pavement structure is 16 meters, the total thickness of the first embankment and the first pavement structure is 5 meters, the spacing between multiple plain concrete piles is 2 meters, the diameter of each plain concrete pile is 0.8 meters, the geogrid consists of four layers, each layer is 1 m long, and the four layers total 4 m long, the thickness of the soft soil layer is 11 meters, the total thickness of the sand layer is 34 meters, wherein the sand layer includes a fine sand layer, a medium sand layer and a coarse sand layer in sequence along the direction away from the first embankment, the thickness of the fine sand layer is 10 meters, the thickness of the medium sand layer is 14 meters, the thickness of the coarse sand layer is 10 meters, and the width of the stratum is 50 meters.

[0034] Figure 4 for Figure 3 The numerical model establishment process diagram shown is as follows: Figure 4As shown, four components are sequentially built in the modeling software: the original road section (4a); the expanded road section, which includes four layers of geogrid (4b dashed line) and one layer of first pavement structure (4b); the pile foundation section (4c); and the four components are assembled after being built (4d). The first pavement structure and the second pavement structure are bound together, and the second pavement structure is the master surface and the first pavement structure is the slave surface. The soft soil layer is a Mohr-Coulomb elastoplastic model to describe the plastic deformation and shear failure characteristics of the soil. The sand layer is located on the side of the soft soil layer away from the first pavement structure, that is, the sand layer has a large burial depth and small additional load on the vehicle during driving, and has good elastic deformation characteristics. Therefore, in this embodiment, the sand layer is a linear elastic model. The first embankment and the second embankment both include four stacked embankment layers. The four embankment layers are in an overconsolidated state, and both the first embankment and the second embankment are linear elastic models. The plain concrete piles and the geogrid are both made of elastic materials.

[0035] Based on the data obtained in step 201, and considering the soil layer characteristics, the material parameters of the numerical model are set as follows: the elastic modulus of the first and second pavement structures is 1470 MPa, Poisson's ratio is 0.3, and the unit weight is 2400 kN / m³; the elastic modulus of the first and second embankments is 25 MPa, Poisson's ratio is 0.25, and the unit weight is 1950 kN / m³; the elastic modulus of the soft soil layer below the first embankment is 4 MPa, Poisson's ratio is 0.45, the unit weight is 1750 kN / m³, the internal friction angle is 15 degrees, and the cohesion is 14.5 kPa; the elastic modulus of the soft soil layer below the second embankment is 40 MPa, Poisson's ratio is 0.3, and the unit weight is 19 kN / m³. The elastic modulus of the fine sand layer in the sand layer is 25 MPa, the Poisson's ratio is 0.25, and the unit weight is 1950 kN / m³; the elastic modulus of the medium sand layer in the sand layer is 35 MPa, the Poisson's ratio is 0.25, and the unit weight is 2000 kN / m³; the elastic modulus of the coarse sand layer in the sand layer is 40 MPa, the Poisson's ratio is 0.25, and the unit weight is 2000 kN / m³; the elastic modulus of the geogrid is 200 MPa, the Poisson's ratio is 0.3, and the unit weight is 1200 kN / m³; the elastic modulus of the plain concrete pile is 22000 MPa, the Poisson's ratio is 0.2, and the unit weight is 2400 kN / m³.

[0036] Step 203: Obtain multiple reinforcement parameter groups. Each reinforcement parameter group includes the pile length of the plain concrete pile in the pile foundation and the parameters of the geogrid in the first embankment. The parameters in any two reinforcement parameter groups are not all the same. The four embankment layers are arranged sequentially in the direction away from the strata: the first embankment layer, the second embankment layer, the third embankment layer, and the fourth embankment layer.

[0037] Step 203 includes: 1. Obtain the four undetermined pile lengths of plain concrete piles, which are 7 meters, 9 meters, 11 meters and 13 meters respectively.

[0038] The spacing and diameter of the four plain concrete piles remain unchanged at 2 m and 0.8 m, respectively.

[0039] 2. Obtain the four configuration structures of the geogrid. The four configuration structures are: Geogrids were laid at the bottom of the first embankment layer; Geogrids were laid at the bottom of the first and second embankment layers respectively; Geogrids were laid at the bottom of the first, second, and third embankment layers, respectively. Geogrids were laid at the bottom of the first, second, third, and fourth embankment layers respectively. 3. Based on four undetermined pile lengths, four geogrid configurations, and orthogonal test methods, multiple sets of reinforcement parameters were obtained.

[0040] Multiple reinforcement parameter groups can be represented by serial numbers No.1 to No.16, as shown in Table 1 below: Table 1. Reinforcement Parameter Group Design Table

[0041] Step 204: Apply an equivalent uniformly distributed live load greater than the preset value to the first pavement structure of the numerical model and the original road.

[0042] Equivalent Uniform Live Load refers to a hypothetical live load that is uniformly distributed throughout the entire load-bearing area, which is converted from non-uniformly distributed live loads (such as concentrated loads, local loads, moving loads, etc.) that may actually occur on the structure, according to the principle of producing the same maximum load effect (such as maximum bending moment, maximum shear force, etc.) on the structure.

[0043] Step 204 includes: 1. Shield the first embankment and the first pavement structure in the numerical model; 2. Apply gravity to the second pavement structure, the second embankment, and the strata, and balance the ground stress; 3. From the ground upwards, activate the four embankment layers and the first pavement structure respectively, and apply gravity to the first pavement structure and the first embankment; 4. Apply an equivalent uniformly distributed live load greater than the preset value to the first pavement structure and the second pavement structure. The preset value is 11 kPa.

[0044] According to the vehicle load calculation method mentioned in the "General Specifications for Highway Bridge and Culvert Design", the equivalent uniformly distributed live load can be calculated using finite element analysis. The specific equivalent uniformly distributed live load value and calculation method are not limited in this embodiment. For example, when the traffic volume in the construction area is large, and there are many heavy trucks, to ensure sufficient safety, the preset value of the equivalent uniformly distributed live load can be set to 11 kPa, or optionally, 14 kPa.

[0045] Step 205: When plain concrete piles and geogrids are not set in the pile foundation in the numerical model, obtain the unreinforced settlement data and unreinforced horizontal displacement data of the numerical model.

[0046] Unreinforced settlement data includes settlement values ​​at multiple locations in the numerical model when no plain concrete piles or geogrids are installed. Similarly, unreinforced horizontal displacement data includes horizontal displacement values ​​at multiple locations in the numerical model when no plain concrete piles or geogrids are installed.

[0047] Figure 5 This application provides a vertical displacement cloud map, such as... Figure 5 As shown, when no reinforcement treatment is carried out on the soft soil layer of the expanded road and the first embankment, the original soft soil layer and the expanded soft soil layer experience significant settlement. Figure 5 The dashed line indicates areas with settlement greater than 4 cm. This area is quite large, almost covering the entire area of ​​the expanded road. Under the additional load, the original soft soil layer and the secondary pavement structure also experienced significant settlement, which will seriously affect the stability and safety of the highway.

[0048] Figure 6 This is a vertical displacement curve provided in an embodiment of this application, such as... Figure 6 As shown, the maximum settlement of the soft soil layer without reinforcement reached 11.487 cm, approximately located at the center of the expanded road. The settlement at the junction of the first and second embankments was 8.245 cm, resulting in a settlement difference of 3.242 cm between them. The area where the soft soil layer of the expanded road contacts the original soft soil layer is within a range of approximately 22-32 m from the center of the original road, with an average settlement of 9.412 cm within this range. Therefore, it is evident that significant settlement and differential settlement will occur when the expanded road is not reinforced.

[0049] Step 206: Based on the unreinforced settlement data and the unreinforced horizontal displacement data, obtain the unreinforced displacement data of the numerical model.

[0050] Step 207: Load multiple reinforcement parameter sets into the numerical model to obtain the settlement data and horizontal displacement data of the numerical model corresponding to each reinforcement parameter set.

[0051] Settlement data includes settlement values ​​at multiple locations in the numerical model, and horizontal displacement data includes horizontal displacement values ​​at multiple locations in the numerical model.

[0052] Figure 7 This is another vertical displacement cloud map provided in the embodiments of this application. Figure 7 The diagram shows the vertical displacement contour maps for plain concrete piles with lengths of 7 m, 9 m, 11 m, and 13 m after laying a layer of geogrid. These are the vertical displacement contour maps for No. 1 to No. 4 in Table 1 above. Figure 7 As shown, one year after the expanded road opened to traffic, the soft soil layer of the expanded road experienced significant settlement, while the soft soil layer of the original road (i.e., the second embankment and the second pavement structure) experienced less settlement. With the increase in the length of the plain concrete piles, the settlement of the soft soil layers of both the expanded and original roads decreased significantly. The dotted lines in the figure represent areas with settlement greater than 4 cm. This area decreases significantly with the increase in the length of the plain concrete piles and gradually shifts to the junction of the soft soil layers of the expanded and original roads. This is because the soft soil layer of the original road has largely consolidated after long-term operation, while the soft soil layer of the expanded road has continued to consolidate and settle after opening to traffic, resulting in a significant settlement difference between the two roads. Figure 7 It was also found that the length of the plain concrete piles has a significant impact on the settlement of the soft soil layer. When the pile length is 7 m, the maximum settlement is 5.886 cm; when the pile length is 9 m, 11 m, and 13 m, the maximum settlements are 5.022 cm, 4.512 cm, and 4.263 cm, respectively. Appropriately increasing the pile length can effectively control the settlement of the soft soil layer, and the longer the plain concrete pile, the better the settlement control effect. However, the settlement control effect is poor at the junction of the soft soil layer between the expanded road and the original road.

[0053] Figure 8 This is a vertical displacement curve provided in an embodiment of this application. Figure 8 The black square markings represent the displacement curves of the roadbed without any reinforcement treatment; the red circles, blue equilateral triangles, green inverted triangles, and purple diamond markings represent the result curves for "one layer of geogrid + 7m piles", "one layer of geogrid + 9m piles", "one layer of geogrid + 11m piles", and "one layer of geogrid + 13m piles", respectively. Figure 8It can be seen that when the length of the plain concrete pile is 7 m, the maximum settlement reaches 5.886 cm, which occurs at a distance of 25.5 m from the center of the original road. The average settlement within 22 to 32 m from the center of the original road (the contact range between the first road embankment and the soft soil layer) reaches 5.024 cm. A settlement difference of 0.845 cm occurs between the soft soil layer connection between the expanded road and the original road and the maximum settlement point. When the pile length is 9 m, the maximum settlement is 5.022 cm, occurring approximately 24.5 m from the center of the original road. The average settlement within the 22-32 m range is 4.168 cm, and the settlement difference between the soft soil layer junction of the expanded road and the original road and the maximum settlement point is 0.574 cm. When the pile length is 11 m, the maximum settlement is 4.512 cm, the average settlement within the contact section is 3.336 cm, and the settlement difference is 0.517 cm. When the pile length is 13 m, the maximum settlement, average settlement, and settlement difference are 4.263 cm, 3.076 cm, and 0.497 cm, respectively. Appropriately increasing the pile length can effectively reduce not only the absolute settlement of the soft soil layer but also the differential settlement between the expanded road and the original road in the soft soil layer. It is also known that when the pile length exceeds 11 m and penetrates the soft soil layer to reach the bearing layer, the effect of increasing the pile length on controlling roadbed settlement is no longer significant. The maximum settlement and differential settlement decrease by only 0.249 cm and 0.26 cm respectively, which can be ignored in engineering. Therefore, the pile length can be designed to be 11 m.

[0054] Figure 9 This is another vertical displacement cloud map provided in the embodiments of this application. Figure 9 The diagram shows the vertical displacement contour maps for four layers of geogrid with plain concrete pile lengths of 7 m, 9 m, 11 m, and 13 m. These correspond to the vertical displacement contour maps No. 13 to No. 16 in Table 1 above. When the pile lengths are 7 m, 9 m, 11 m, and 13 m, the maximum settlements are 5.474 cm, 4.789 cm, 4.302 cm, and 4.060 cm, respectively. The settlement of the soft soil layer is reduced, but the reduction is small. Therefore, laying four layers of geogrid did not achieve the expected effect. The area within the dashed circle in the diagram represents the area with a settlement greater than 4 cm. This area exhibits the same pattern as when only one layer of geogrid is laid, and will not be elaborated further here.

[0055] Figure 10 This is a vertical displacement curve provided in an embodiment of this application. Figure 10 The black square markings represent the displacement curve of the roadbed without any reinforcement treatment; the red circles, blue equilateral triangles, green inverted triangles, and purple diamond markings represent the result curves for "four layers of geogrid + 7m piles", "four layers of geogrid + 9m piles", "four layers of geogrid + 11m piles", and "four layers of geogrid + 13m piles", respectively. Figure 10The maximum settlements were 5.474, 4.789, 4.302, and 4.060 cm, occurring at distances of 25.1 m, 23.4 m, 20.4 m, and 20 m from the center of the original road, respectively. The average settlements within a range of 22–32 m from the center of the original road were 4.755 cm, 3.942 cm, 3.171 cm, and 2.926 cm, respectively. The settlement differences between the soft soil layer junction of the expanded road and the original road and the maximum settlement point were 0.664 cm, 0.538 cm, 0.472 cm, and 0.461 cm, respectively. The results show that when four layers of geogrid were laid, the settlement of the soft soil layer with pile length exhibited the same trend as when only one layer of geogrid was laid.

[0056] In one embodiment provided in this application, multiple reinforcement parameter groups are loaded into the numerical model respectively to obtain the settlement data of the numerical model corresponding to each reinforcement parameter group. Table 2 is a table of settlement data of the unreinforced plain concrete piles and geogrids in the unreinforced pile foundations in step 205, which are serial numbers No.1 to No.16 in Table 1. Table 2 Settlement data from numerical simulation

[0057] As shown in Table 2 above, reinforcing the soft soil layer and the first embankment can significantly and effectively reduce the maximum settlement, average settlement, and uneven settlement of the soft soil layer. The overlap is the connection between the original road and the expanded road. Analysis of the above data shows the different effects of different reinforcement parameter groups on settlement. For example, when the plain concrete piles are at 7 m, 9 m, 11 m, and 13 m, and the geogrid is placed at the bottom of the first, second, and third embankment layers (No. 9-No. 12 in Table 2), the maximum settlement is 5.568 cm, 4.860 cm, 4.364 cm, and 4.120 cm, respectively; the average settlement is 4.836 cm, 4.020 cm, 3.225 cm, and 2.975 cm, respectively; and the differential settlement is 0.679 cm, 0.521 cm, 0.492 cm, and 0.479 cm, respectively. The data above shows that as the length of the plain concrete piles increases, all settlement parameters of the soft soil layer decrease significantly. Taking the maximum settlement as an example, compared with the unreinforced state (11.487 cm), the maximum settlement decreased by 52%, 58%, 62%, and 64%, respectively. Therefore, the reduction in settlement is more significant when the length of the plain concrete piles increases from 7 m to 11 m; however, when the length increases from 11 m to 13 m, the reduction in settlement decreases significantly, and the effect is no longer noticeable.

[0058] The data in Table 2 above also demonstrate the settlement control effect of geogrids. For example, using 11 m long plain concrete piles as an example, data from one to four layers of geogrid (Tests No. 3, No. 7, No. 11, and No. 15) on the embankment show the following: Maximum settlement was 4.512 cm, 4.418 cm, 4.364 cm, and 4.302 cm respectively; average settlement was 3.336 cm, 3.278 cm, 3.225 cm, and 3.171 cm respectively; and differential settlement was 0.517 cm, 0.501 cm, 0.492 cm, and 0.472 cm respectively. Increasing the number of geogrid layers did not significantly improve settlement control. Since the tensile strength of geogrid material is much higher than its compressive strength, its main function is to control horizontal displacement.

[0059] In another embodiment provided in this application, multiple sets of reinforcement parameters are loaded into the numerical model to obtain the horizontal displacement data of the numerical model corresponding to each set of reinforcement parameters. Figure 11 This is a horizontal displacement curve of a soft soil layer when different layers of geogrid are laid, provided as an embodiment of this application. Figure 11 The diagram shows the horizontal displacement curves of the soft soil layer monitoring line under different layers of geogrid one year after the road opened to traffic, when the embankment is 11 m long and the pile is plain concrete. Without geogrid treatment, the maximum horizontal displacement reaches 6.881 cm. Areas with significant horizontal displacement occur within 25-35 m of the old road center, with an average horizontal displacement of 6.491 cm in this area. When the embankment is laid with one to four layers of geogrid: the maximum horizontal displacements are 5.351 cm, 5.342 cm, 5.274 cm, and 5.243 cm, respectively; the average horizontal displacements within the 25-35 m range are 5.210 cm, 5.176 cm, 5.102 cm, and 4.926 cm, respectively. Therefore, from... Figure 11 It can be seen that, compared with the untreated embankment, the use of geogrid reinforcement can effectively reduce the horizontal displacement of the soft soil layer. Using one layer of geogrid, the maximum horizontal displacement is reduced by 1.530 cm, and the average horizontal displacement is reduced by 1.281 cm. However, increasing the number of geogrid layers only results in a small change in horizontal displacement, and the reduction is no longer significant. Since the length of the plain concrete pile has little impact on the horizontal displacement, the horizontal displacement data for plain concrete piles with lengths of 7 m, 9 m, 11 m, and 13 m in this application embodiment are similar, and the same horizontal displacement data is used for all of them.

[0060] Step 208: Determine whether the sum of displacement data of the reinforcement parameter group with the smallest sum is less than the sum of displacement data of the unreinforced group; if it is less than the sum of displacement data of the unreinforced group, proceed to step 209; if it is not less than the sum of displacement data of the unreinforced group, adjust the multiple reinforcement parameter groups and proceed to step 207.

[0061] Step 209: Determine the target reinforcement parameter group as the reinforcement parameter group with the smallest displacement data among multiple reinforcement parameter groups.

[0062] The displacement data is the sum of the settlement data and the horizontal displacement data of the numerical model corresponding to the reinforcement parameter set.

[0063] Step 209 includes: 1. Obtain the maximum settlement value from the settlement data of any one of the multiple reinforcement parameter groups; 2. When the maximum settlement value is less than or equal to the settlement threshold, obtain the average settlement value of multiple locations in the target area of ​​the numerical model in any reinforcement parameter group. The target area is the area in the numerical model where the settlement value is greater than or equal to 4 cm. 3. Obtain the maximum horizontal displacement value from the horizontal displacement data of any one of the multiple reinforcement parameter groups; 4. When the maximum horizontal displacement value is less than or equal to the horizontal displacement threshold, obtain the average horizontal displacement value of multiple locations in the target area of ​​the numerical model in any reinforcement parameter group. 5. The sum of the average settlement value and the average horizontal displacement value is determined as the displacement data of any reinforcement parameter group.

[0064] As shown in Table 1 above, geogrids No. 1 to No. 4 correspond to one layer with an average horizontal displacement of 5.210 cm; No. 5 to No. 8 correspond to two layers with an average horizontal displacement of 5.176 cm; No. 9 to No. 12 correspond to three layers with an average horizontal displacement of 5.102 cm; and No. 13 to No. 16 correspond to four layers with an average horizontal displacement of 4.926 cm. The average horizontal displacement without reinforcement is 6.491 cm. Based on the average vertical displacements in Table 2 above, the total displacement for the unreinforced parameter group is 15.903 cm; the total displacement for the reinforced parameter group No.1 is 10.234 cm; the total displacement for the reinforced parameter group No.2 is 9.378 cm; the total displacement for the reinforced parameter group No.3 is 8.546 cm; the total displacement for the reinforced parameter group No.4 is 8.286 cm; the total displacement for the reinforced parameter group No.5 is 10.141 cm; the total displacement for the reinforced parameter group No.6 is 9.265 cm; the total displacement for the reinforced parameter group No.7 is 8.454 cm; the total displacement for the reinforced parameter group No.8 is 8.200 cm; the total displacement for the reinforced parameter group No.9 is 9.938 cm; and the total displacement for the reinforced parameter group No.10 is 9.122 cm. The displacement data for reinforcement parameter group No. 11 is 8.327 cm; the displacement data for reinforcement parameter group No. 12 is 8.077 cm; the displacement data for reinforcement parameter group No. 13 is 9.681 cm; the displacement data for reinforcement parameter group No. 14 is 8.868 cm; the displacement data for reinforcement parameter group No. 15 is 8.097 cm; and the displacement data for reinforcement parameter group No. 16 is 7.852 cm.

[0065] Step 210: Widen the road using the target reinforcement parameter set.

[0066] The smallest displacement data among the above is No. 16, which represents the reinforcement parameter group for a pile length of 13 meters and a grid layer of 4 layers. Therefore, the target reinforcement parameter group is a plain concrete pile with a pile length of 13 meters and a grid layer of 4 layers.

[0067] Of course, in an exemplary embodiment, since the displacement data of the No.3 reinforcement parameter group is 8.546cm, it has a good control effect on settlement and horizontal displacement. Therefore, the method provided in this application embodiment can also use the No.3 reinforcement parameter group as the target reinforcement parameter group to save costs.

[0068] In summary, the coastal road widening construction method provided in this application establishes a numerical model based on geological parameters, road width, and the desired widening width. This numerical model simulates multiple reinforcement parameter sets to obtain settlement and horizontal displacement data for each set after reinforcement. The reinforcement parameter set with the smallest displacement data is then selected as the target reinforcement parameter set, and the road is widened using this target set. This method allows for the determination of reinforcement methods with smaller settlement and horizontal displacement through model simulation, enabling flexible application in various road widening constructions and enhancing the method's flexibility.

[0069] In this application, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0070] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

Claims

1. A widening construction method of a coastal road, characterized by, The method for widening a road in a coastal area comprises the following steps: obtaining stratum parameters of a region to be constructed, a width of the road, and a width to be widened, wherein the region to be constructed comprises, in sequence from the ground surface, a soft soil layer and a sand layer; establishing a numerical model based on the stratum parameters, the width of the road, and the width to be widened, wherein the numerical model comprises a stratum, an original road, and an extension road on the stratum, the original road and the extension road are connected, the extension road comprises a first embankment and a first pavement structure on the first embankment, the first embankment is provided with a geogrid, and the stratum under the first embankment is provided with a pile foundation; obtaining a plurality of reinforcement parameter groups, each of the reinforcement parameter groups comprises a pile length of a concrete pile in the pile foundation and parameters of the geogrid in the first embankment, and parameters in any two of the reinforcement parameter groups are not all the same; applying an equivalent uniform live load greater than a preset value to the first pavement structure and the original road of the numerical model; loading the numerical model with the plurality of reinforcement parameter groups respectively to obtain settlement data and horizontal displacement data of the numerical model corresponding to each of the reinforcement parameter groups, wherein the settlement data comprises settlement values of a plurality of positions of the numerical model, and the horizontal displacement data comprises horizontal displacement values of a plurality of positions of the numerical model; determining a target reinforcement parameter group from the reinforcement parameter groups with the smallest displacement data and, wherein the displacement data and is a sum of the settlement data and the horizontal displacement data of the numerical model corresponding to the reinforcement parameter group; widening the road by using the target reinforcement parameter group.

2. The method of claim 1, wherein, The method further comprises the following steps before loading the numerical model with the plurality of reinforcement parameter groups respectively: obtaining a maximum settlement value in the settlement data of any one of the reinforcement parameter groups; obtaining an average settlement value of settlement values of a plurality of positions in a target region of the numerical model in the any one of the reinforcement parameter groups when the maximum settlement value is less than or equal to a settlement threshold value, wherein the target region is a region in the numerical model with a settlement value greater than or equal to 4 cm; obtaining a maximum horizontal displacement value in the horizontal displacement data of any one of the reinforcement parameter groups; obtaining an average horizontal displacement value of horizontal displacement values of a plurality of positions in the target region of the numerical model in the any one of the reinforcement parameter groups when the maximum horizontal displacement value is less than or equal to a horizontal displacement threshold value; determining a sum of the average settlement value and the average horizontal displacement value as a displacement data and of the any one of the reinforcement parameter groups.

3. The method of claim 2, wherein, The method further comprises the following steps before loading the numerical model with the plurality of reinforcement parameter groups respectively: obtaining un-reinforced settlement data and un-reinforced horizontal displacement data of the numerical model when the numerical model is not provided with the concrete pile in the pile foundation and the geogrid; obtaining an un-reinforced displacement data and of the numerical model based on the un-reinforced settlement data and the un-reinforced horizontal displacement data; Before the step of determining the reinforcement parameter group with the minimum sum of displacement data in the plurality of reinforcement parameter groups as the target reinforcement parameter group, the method further comprises: determining whether the sum of displacement data and minimum sum of displacement data in the plurality of reinforcement parameter groups is less than the sum of displacement data of the un-reinforced; when less than the sum of displacement data of the un-reinforced, performing the step of determining the reinforcement parameter group with the minimum sum of displacement data in the plurality of reinforcement parameter groups as the target reinforcement parameter group; when not less than the sum of displacement data of the un-reinforced, adjusting the plurality of reinforcement parameter groups, and performing the step of respectively loading the plurality of reinforcement parameter groups into the numerical model.

4. The method of claim 2, wherein, In the numerical model, the original road comprises a second embankment and a second pavement structure on the second embankment, the second pavement structure is connected with the first pavement structure, the second embankment is connected with the first embankment, the ground layer comprises a soft soil layer and a sand layer arranged in turn along the ground surface, the first embankment and the second embankment are located on the soft soil layer, and the pile foundation is located in the soft soil layer below the first embankment.

5. The method of claim 4, wherein, In the numerical model, the first pavement structure and the second pavement structure are binding constraints, the second pavement structure is a master surface, the first pavement structure is a slave surface, the soft soil layer is a Mohr-Coulomb elastic-plastic model, the sand layer is a linear elastic model, the first embankment and the second embankment each comprise four embankment layers stacked together, the four embankment layers are in an over-consolidated state, and the first embankment and the second embankment are linear elastic models, and the plain concrete pile and the geogrid are each composed of an elastic material.

6. The method of claim 5, wherein, The step of applying an equivalent uniform live load greater than a preset value to the first pavement structure of the numerical model and the original road comprises: shielding the first embankment and the first pavement structure in the numerical model; applying gravity to the second pavement structure, the second embankment and the ground layer and performing ground stress balancing; respectively activating the four embankment layers and the first pavement structure from the upward direction of the ground layer, and applying gravity to the first pavement structure and the first embankment; applying an equivalent uniform live load greater than the preset value to the first pavement structure and the second pavement structure, the preset value being 11 kilopascals.

7. The method of claim 5, wherein, The four embankment layers are a first embankment layer, a second embankment layer, a third embankment layer and a fourth embankment layer arranged in turn in a direction away from the ground layer. The step of obtaining a plurality of reinforcement parameter groups comprises: obtaining four to-be-determined pile lengths of the plain concrete pile, the four to-be-determined pile lengths being 7 meters, 9 meters, 11 meters and 13 meters respectively; obtaining four setting structures of the geogrid, the four setting structures being: laying the geogrid at the bottom of the first embankment layer; laying the geogrid at the bottom of the first embankment layer and the second embankment layer respectively; laying the geogrid at the bottom of the first embankment layer, the second embankment layer and the third embankment layer respectively; laying the geogrid at the bottom of the first embankment layer, the second embankment layer, the third embankment layer and the fourth embankment layer respectively; Based on the four pending pile lengths, four setting structures of the geogrid and the orthogonal test method, the multiple reinforcement parameter groups are obtained.

8. The method of claim 5, wherein, The elastic modulus of the first pavement structure and the second pavement structure is 1470 MPa, the Poisson's ratio is 0.3, and the unit weight is 2400 kN / m3; The elastic modulus of the first embankment is 4 MPa, the Poisson's ratio is 0.45, and the unit weight is 1750 kN / m3; The elastic modulus of the second embankment is 25 MPa, the Poisson's ratio is 0.25, and the unit weight is 1950 kN / m3.

9. The method of claim 5, wherein, The numerical model is a half-width model including the road and half of the structure of the expanded road; In the numerical model, the width of the first pavement structure is 8 meters, the width of the second pavement structure is 16 meters, the thickness of the first embankment and the first pavement structure is 5 meters, the thickness of the soft soil layer is 11 meters, the thickness of the sand layer is 34 meters, and the width of the stratum is 50 meters.

10. The method of claim 1, wherein, The pile foundation includes multiple concrete piles, the pile spacing of the multiple concrete piles is two meters, and the pile diameter of each concrete pile is 0.8 meters.

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