Earth-rock stockpiling and deploying method based on backhaul demand

Abstract

The invention discloses an earthwork stockpiling and deploying method based on a return demand, and the method comprises the steps: introducing decision variables, and representing the types of stockpiling fields, the types of earthwork stockpiling in the stockpiling fields, and the amounts of various earthwork coming and going between each excavation field and each stockpiling field through the decision variables; based on the type of the stockpiling yard, the excavation and return demand, the capacity of the stockpiling yard and the actual value range of each decision variable, establishing association constraints about the decision variables; determining a first measurement target and a second measurement target by minimizing the total transportation distance and minimizing the amount of earth and stone excavated and returned from the mixed stockpiling yard, introducing a trade-off coefficient, and constructing a mixed integer linear programming model in combination with association constraints; and substituting the numerical value to solve the mixed integer linear programming model, and determining an optimized earth-rock stockpiling allocation scheme. According to the method, a classified stockpiling strategy is set, the transportation distance and the backhaul excavation volume are comprehensively considered under the constraint condition, limited resources are reasonably utilized, and a solution with higher efficiency and lower cost is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of optimizing the storage and deployment of earth and stone in earth and stone engineering, and in particular, relates to an earth and stone storage and deployment method based on return transportation demand. Background Art

[0002] Earthwork balance is an important task in earthwork engineering. Its main purpose is to scientifically and rationally allocate excavation and filling to achieve the overall economic, environmental protection and construction efficiency requirements of the project. During the construction of the project, excavated materials (earthwork) usually need to be stored in a special site. The specific quantity, type and storage time of the stored earthwork are affected by many factors such as geological conditions, engineering design and construction progress. In some engineering projects, due to construction needs or design changes, it may be necessary to transport some of the stored earthwork back to the excavation site. For example, in major canal projects, the topsoil excavated from the excavation site needs to be reclaimed in the excavation site in the later stage. Therefore, during construction, the topsoil of the excavation site is usually transported to the storage site for storage, and then transported back to the excavation site when reclamation is required.

[0003] However, most traditional methods of earthwork stockpiling and allocation ignore the diversity of earthwork types, and mix earthwork (such as topsoil) that needs to be transported back with other types of earthwork. During reclamation, it is necessary to excavate the earthwork (such as topsoil) that needs to be transported back from the mixed stockpiles, which increases unnecessary excavation costs and delays the construction progress. It fails to reasonably maximize the engineering value and utilization efficiency of different types of earthwork. In addition, due to the differences in the size, shape and texture of particles in various types of earthwork, mixed stockpiling will make earthwork more susceptible to water and wind erosion, resulting in earthwork loss.

[0004] Therefore, based on the return transportation needs in the project, how to rationally plan and formulate a plan to store and allocate the excavated earth and stone so as to minimize the excavation cost of the earth and stone from the storage yard and the transportation cost during the transportation out and back is an issue that needs to be solved urgently. Summary of the invention

[0005] The present invention is made to solve the above-mentioned problem, and aims to provide a method for storing and allocating earth and stone based on return transportation demand.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for stockpiling and allocating earth and stone based on return transportation demand, comprising:

[0008] Step S1: Taking the number and location of excavation sites, the number and location of stockpiles, the capacity of each stockpile, the types of earthwork, and the excavation demand and return demand of each type of earthwork as known conditions, multiple decision variables are introduced, and the types of stockpiles, the types of earthwork corresponding to the stockpiles, and the corresponding types of earthwork volume between each excavation site and each stockpile are represented by decision variables. The stockpile types include classified stockpiles and mixed stockpiles.

[0009] Step S2: establishing association constraints on decision variables based on the stockpile type, earthwork excavation demand and return demand, stockpile capacity, and actual value ranges of each decision variable;

[0010] Step S3: determining the first measurement target and the second measurement target by minimizing the total earthwork transportation distance and minimizing the earthwork volume excavated and transported back from the mixed stockpile, respectively, introducing a trade-off coefficient between the first measurement target and the second measurement target, and further constructing a mixed integer linear programming model in combination with the associated constraints;

[0011] Step S4: Determine the trade-off coefficient according to actual needs, substitute the specific values ​​of the known conditions, solve the mixed integer linear programming model, obtain the quantity of each type of earth and stone transported from each excavation site to each stockpile, and the quantity of each type of earth and stone transported back from each stockpile to each excavation site, and determine the earth and stone stockpile allocation plan.

[0012] Further, in step S1, it is assumed that: the set of earthwork types is K, the set of excavation sites is I, the set of storage sites is J, and the set of excavation sites is right Earthwork The excavation demand is , the return demand is , storage yard The design capacity is , then the decision variables include:

[0013] Stockpile Type Variable ——Indicates whether the storage yard is used as a classified storage yard, and 1 indicates a storage yard Used as a classification dump, 0 means a dump used as a mixed stockpile;

[0014] Variables of stockpile type ——Indicates a storage yard Is it only storage? Earthwork, 1 means storage area Stockpile only Earthwork, 0 means storage area Not only storage Class earthwork;

[0015] Mixed field stockpile variables ——Indicates from the excavation site To the stockpile Mixed stockpile Earthwork volume;

[0016] Classification field stockpile variables ——Indicates from the excavation site To the stockpile Classified storage Earthwork volume;

[0017] Mixed field return variable ——Indicates the mixed stockpile storage area To the excavation site Return Earthwork volume;

[0018] Classification field return variables ——Indicates the stockpile from classified stockpile To the excavation site Return Earthwork volume,

[0019] in, and is a binary decision variable, , , as well as are all non-negative continuous decision variables.

[0020] Further, in step S2, a first constraint formula is established based on the storage yard type. , which means that when the storage yard is set as a classified storage yard, it can and only can classify and store one type of earth and stone; when the storage yard is set as a mixed storage yard, it cannot classify and store a certain type of earth and stone.

[0021] Further, in step S2, based on the stockpile type variable in the decision variable and stockpile type variables The actual value range of the second constraint is established and the third constraint .

[0022] Furthermore, in step S2, a fourth constraint formula is established based on the earthwork storage demand and the return transportation demand: and the fifth constraint , which are used to ensure that the sum of the earth and stone volume transported from the excavation site to the classification stockpile and the mixed stockpile meets the excavation demand, and the sum of the earth and stone volume transported back from the classification stockpile and the mixed stockpile to the excavation site meets the return transportation demand.

[0023] Furthermore, in step S2, the sixth constraint is established: , which is used to ensure that the return volume of various types of earth and stone in the mixed stockpile is not greater than the stockpile volume; and the seventh constraint , used to ensure that the amount of earth and stone returned from the classified stockpile is not greater than the stockpile amount.

[0024] Further, in step S2, based on the mixed field stockpile variable in the decision variable , Classification field stockpile variables , mixed field return variables and the classification field return variables The actual value range of the eighth constraint is established , the ninth constraint , the tenth constraint , the eleventh constraint .

[0025] Further, in step S2, based on the storage yard capacity, a twelfth constraint formula is established: , used to ensure that the total amount of earth and rock transported into the mixed stockpile does not exceed its design capacity, and the thirteenth constraint , used to ensure that the amount of a specific type of earth and rock transported into a classification stockpile does not exceed its design capacity.

[0026] Furthermore, in step S3, the first measurement objective is determined by minimizing the total transportation distance during the earthwork storage and return transportation process. ,in, express Excavation site and Transportation distances between stockpiles; the second metric is to minimize the amount of earth and rock excavated and transported back from the mixed stockpile , introduce a trade-off coefficient between the first measurement objective and the second measurement objective , establish comprehensive measurement goals ,Further combine the comprehensive measurement objectives with the ,associated constraints of the decision variables, a mixed integer linear ,programming model is constructed.

[0027] Preferably, the trade-off coefficient The value of is 0.5.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The earthwork stockpile allocation method based on return transport demand of the present invention establishes a zoning and classification stockpile strategy under multiple constraints such as engineering demand and design capacity of the stockpile yard, comprehensively considers the transportation distance and return excavation volume, and can reasonably utilize limited resources to formulate more efficient and low-cost solutions, which is conducive to the smooth progress of engineering projects.

[0030] 2. The earthwork stockpile allocation method based on the return demand of the present invention can reasonably set the types of each stockpile so that the earthwork that needs to be returned can be stored more independently in the classified stockpile, and the amount of earthwork excavated from the mixed stockpile during return is minimized, which not only avoids the extra manpower and material resources required for excavation, but also reduces the loss that may be caused by excavating topsoil from the mixed stockpile. Compared with the traditional mixed stockpile of various earthworks, the zoning and classification stockpile strategy is also more friendly to the ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of the earthwork stockpile allocation method based on the return transportation demand;

[0032] Figure 2 It is a schematic diagram of the location of the excavation site and the stockpile site;

[0033] Figure 3 It is a schematic diagram of the direction of earth and stone transportation. DETAILED DESCRIPTION

[0034] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and the accompanying drawings specifically illustrate the earth and stone stockpile allocation method based on the return transportation demand of the present invention.

[0035] Example 1

[0036] like Figure 1 As shown, the present invention provides a method for stockpiling and allocating earth and stone based on return transportation demand, comprising:

[0037] Step S1: Taking the number and location of excavation sites, the number and location of stockpiles, the capacity of each stockpile, the types of earthwork, and the excavation demand and return demand of each type of earthwork as known conditions, multiple decision variables are introduced to represent the type of stockpile, the type of earthwork stored in the stockpile, and the corresponding type of earthwork volume between each excavation site and each stockpile, wherein the stockpile type includes classified stockpile and mixed stockpile;

[0038] Step S2: establishing association constraints on decision variables based on conditions such as the stockpile type, earthwork excavation demand and return demand, stockpile capacity, and actual value ranges of each decision variable;

[0039] Step S3: determining the first measurement target and the second measurement target by minimizing the total earthwork transportation distance and minimizing the earthwork volume excavated and transported back from the mixed stockpile, respectively, introducing a trade-off coefficient between the first measurement target and the second measurement target, and further constructing a mixed integer linear programming model in combination with all associated constraints;

[0040] Step S4: Determine the trade-off coefficient according to actual needs, substitute the specific values ​​of the known conditions, solve the mixed integer linear programming model, obtain the quantity of each type of earth and stone transported from each excavation site to each stockpile, and the quantity of each type of earth and stone transported back from each stockpile to each excavation site, and determine the earth and stone stockpile allocation plan.

[0041] Further, in step S1, it is assumed that: the set of earthwork types is K, the set of excavation sites is I, the set of storage sites is J, and the set of excavation sites is right Earthwork The excavation demand is , the return demand is , storage yard The design capacity is , then the decision variables include:

[0042] Stockpile Type Variable ——is a binary decision variable, indicating whether the storage yard is used as a classified storage yard, and 1 indicates a storage yard. Used as a classification dump, 0 means a dump used as a mixed stockpile;

[0043] Variables of stockpile type ——is a binary decision variable, indicating the storage site Is it only storage? Earthwork, 1 means storage area Stockpile only Earthwork, 0 means storage area Not only storage Class earthwork;

[0044] Mixed field stockpile variables ——is a non-negative continuous decision variable, indicating that To the stockpile Mixed stockpile Earthwork volume;

[0045] Classification field stockpile variables ——is a non-negative continuous decision variable, indicating that To the stockpile Classified storage Earthwork volume;

[0046] Mixed field return variable ——is a non-negative continuous decision variable, indicating the stockpile site from mixed stockpile To the excavation site Return Earthwork volume;

[0047] Classification field return variables ——is a non-negative continuous decision variable, representing the storage site from classified storage To the excavation site Return Volume of earth and stone.

[0048] Further, in step S2, an association constraint is established based on the storage yard type:

[0049] Each storage yard can only be classified and stored if it is set as a classified storage yard, and can only store one type of earth and stone. hour, ; When the storage yard is set as a mixed storage yard, it is impossible to classify and store any kind of earth and stone. hour, The first constraint is obtained , which means that when the storage yard is set as a classified storage yard, it can and only can classify and store one type of earth and stone; when the storage yard is set as a mixed storage yard, it cannot classify and store only one type of earth and stone.

[0050] In addition, since the storage site type variable in the decision variables and stockpile type variables are binary variables. According to their actual value range, the second constraint can be established: and the third constraint .

[0051] Furthermore, the associated constraints are established based on the earthwork storage demand and return transportation demand:

[0052] The sum of the earthwork volume transported from the excavation site to the classified stockpile and mixed stockpile should meet the excavation demand, and the earthwork volume transported back from the classified stockpile and mixed stockpile to the excavation site should meet the return demand, thus establishing the fourth constraint formula: and the fifth constraint For the convenience of calculation, the excavation volume, stockpiling volume and return volume of earth and stone can all be converted into loose cubic meters.

[0053] Assuming that all storage yards have not stored any earth and stone before the current project is used, that is, the default initial storage volume is 0, then the volume of earth and stone transported back from the storage yard should not be greater than the volume of earth and stone transported into the storage yard. , ensuring that the return volume of various types of earth and stone in the mixed stockpile is not greater than the stockpile volume; and the seventh constraint , ensure that the amount of earth and stone returned from the classified stockpile is not greater than the stockpile amount.

[0054] Furthermore, considering that the actual amount of earth and stone stored and transported back is at least 0, the mixed field storage variable in the decision variable , Classification field stockpile variables , mixed field return variables and the classification field return variables are all non-negative continuous variables, based on , , , The actual value range of the eighth constraint is established , the ninth constraint , the tenth constraint , the eleventh constraint .

[0055] Furthermore, due to the limited capacity of the stockpile, the total stockpile of earth and stone in each stockpile cannot exceed the design capacity of the stockpile, thus establishing the twelfth constraint formula: , used to ensure that the total amount of earth and rock transported into the mixed stockpile does not exceed its design capacity, and the thirteenth constraint , used to ensure that the amount of a specific type of earth and rock transported into a classification stockpile does not exceed its design capacity.

[0056] Further, in step S3, on the one hand, the first measurement objective is determined by minimizing the total transportation distance during the earthwork storage and return transportation process. ,in, express Excavation site and On the other hand, since the earth and stone in the classified stockpile does not need to be excavated, the second measurement target is to minimize the amount of earth and stone excavated and transported back from the mixed stockpile. .

[0057] In the process of earthwork balance, if only the minimum total transportation distance or the minimum return excavation volume is considered, it may lead to a high value for the other item. Therefore, a trade-off coefficient is introduced between the first measurement target and the second measurement target. , establish comprehensive measurement goals . Trade-off coefficient The value of can be determined based on the actual needs of the specific engineering project. Taking both indicators into consideration can not only ensure the convenience of transportation and the efficiency of construction, but also minimize the waste of resources, time, economic costs, etc. caused by excavating earth and stone from the mixed stockpile.

[0058] Furthermore, by combining the comprehensive measurement objectives with all associated constraints of the decision variables, a mixed integer linear programming model is constructed: .

[0059] Furthermore, in step S4, the complexity of the model mainly depends on the number of excavation sites and stockpiles and the types of earthwork. The trade-off coefficient is determined according to the actual project requirements, and the specific values ​​of the known conditions are substituted to solve the mixed integer linear programming model to obtain the quantity of various earthworks stored from each excavation site to each stockpile, and the quantity of various earthworks transported back from each stockpile to each excavation site, and determine the earthwork stockpile allocation plan that satisfies the earthwork balance. Since the constraints are all linear constraints, the commonly used optimization solution software can be used to solve the general scale model to obtain the optimal earthwork stockpile allocation plan for the system.

[0060] Example 2

[0061] For a canal project, in order to meet the predetermined waterway requirements of the project, a large amount of earth and stone will be excavated from the designed river channel. The earth and stone excavated on site needs to be disposed of and transported from the excavation site to the storage site for temporary storage. Later, the topsoil will be transported back from the storage site to the excavation site for reclamation. Therefore, it is necessary to plan and formulate the earth and stone storage allocation method in advance before the formal construction begins, and seek a more efficient and low-cost solution based on the traditional earth and stone balance method.

[0062] First, the known conditions include:

[0063] (1) There are 4 excavation sites, denoted as I1, I2, I3, and I4, and their distribution locations are as follows: Figure 2 shown.

[0064] (2) There are 10 storage yards, denoted as J1, J2, J3, J4, J5, J6, J7, J8, J9, and J10, and their distribution locations are as follows: Figure 2 shown.

[0065] (3) The excavated earth and stone can be divided into three categories, namely topsoil, other earth and stone. Among them, the topsoil needs to be transported back.

[0066] (4) Based on the engineering design and the survey of earthwork, the excavation demand and return transportation demand of various types of earthwork in each excavation site can be estimated. The results are shown in Table 1:

[0067] Table 1 Project demand (unit: ten thousand cubic meters)

[0068]

[0069] To facilitate subsequent calculations, the earthwork quantities involved are all loose cubic meters. The earthwork quantities of each excavation site are actually solid cubic meters before being excavated, and are converted into loose cubic meters using the loose solid coefficient.

[0070] (5) The design capacity of each storage yard is shown in Table 2:

[0071] Table 2 Design capacity of storage yard (unit: ten thousand cubic meters)

[0072]

[0073] (6) The transportation distances between each excavation site and the storage site are shown in Table 3:

[0074] Table 3 Transportation distance (unit: km)

[0075]

[0076] (7) Considering the total transportation distance of the earth and stone stockpile and the amount of earth and stone excavated from the mixed stockpile, the weight coefficient Take 0.5.

[0077] Based on the above known conditions, the model framework is constructed through the earthwork stockpile allocation method of Example 1, and the model is solved using the optimization solution software. After 0.08 seconds of calculation, the quantity of each type of earthwork stored from each excavation site to each stockpile and the quantity of each type of earthwork transported back from each stockpile to each excavation site are obtained, as shown in Table 4, thereby determining the earthwork stockpile allocation plan.

[0078] Table 4 Model solution results (unit: ten thousand square meters)

[0079]

[0080] In Table 4, the values ​​outside and inside brackets represent the volume of earth and stone transported from the excavation site to the stockpile and the volume of earth and stone transported back from the stockpile to the excavation site, respectively. Figure 3 The arrow in the middle indicates the direction of earth and stone transportation. Figure 3 It can be seen that the stockpiles J2, J3, J6 and J9 are set as classified stockpiles, while the other stockpiles are used as mixed stockpiles. Among the classified stockpiles, the J2 and J9 stockpiles are used for classified storage of topsoil, the J3 stockpiles are used for classified storage of stone, and the J6 stockpiles are used for classified storage of other earthworks. According to the statistical calculations based on the values ​​in Table 4, it can be verified that the solution results not only achieve the balance between excavation and filling during the excavation process, but also achieve the balance between excavation and filling during the return transportation process, and do not exceed the capacity limit of each stockpile while meeting the excavation and return transportation requirements. In the final solution, the topsoil that needs to be returned is classified and stored, and there is no need to excavate the topsoil from the mixed stockpiled earth and stone during return transportation. This not only avoids the extra manpower and material resources required for excavation, but also reduces the losses that may be caused by excavating topsoil from the mixed stockpiled earth and stone.

[0081] In summary, the earthwork stockpile allocation method based on return transportation demand of the present invention establishes a zoning and classification stockpile strategy under multiple constraints such as engineering demand and stockpile yard design capacity, comprehensively considers transportation distance and return excavation volume, can reasonably utilize limited resources, and formulates a more efficient and low-cost solution based on earthwork balance, which is conducive to the smooth progress of engineering projects.

[0082] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. A method for stockpiling and allocating earth and stone based on return transportation demand, characterized in that: include: Step S1: Taking the number and location of excavation sites, the number and location of stockpiles, the capacity of each stockpile, the types of earthwork, and the excavation demand and return demand of each type of earthwork as known conditions, multiple decision variables are introduced, and the types of stockpiles, the types of earthwork corresponding to the stockpiles, and the corresponding types of earthwork volume between each excavation site and each stockpile are represented by decision variables. The stockpile types include classified stockpiles and mixed stockpiles. Step S2: establishing association constraints on the decision variables based on the stockpile type, earthwork excavation demand and return demand, stockpile capacity, and actual value ranges of the decision variables; Step S3: determining the first measurement target and the second measurement target by minimizing the total transportation distance of earth and stone and minimizing the amount of earth and stone excavated and transported back from the mixed stockpile, respectively, introducing a trade-off coefficient between the first measurement target and the second measurement target, and further constructing a mixed integer linear programming model in combination with the association constraint; Step S4: Determine the trade-off coefficient according to actual needs, substitute the specific values ​​of the known conditions, solve the mixed integer linear programming model, obtain the quantity of each type of earth and stone transported from each excavation site to each stockpile site, and the quantity of each type of earth and stone transported back from each stockpile site to each excavation site, and determine the earth and stone stockpile allocation plan.

2. The earthwork storage and allocation method based on return transportation demand according to claim 1 is characterized in that: In step S1, it is assumed that: the set of earthwork types is K, the set of excavation sites is I, the set of storage sites is J, and the set of excavation sites is right Earthwork The excavation demand is , the return demand is , storage yard The design capacity is , then the decision variables include: Stockpile Type Variable ——Indicates whether the storage yard is used as a classified storage yard, and 1 indicates a storage yard Used as a classification dump, 0 means a dump used as a mixed stockpile; Variables of stockpile type ——Indicates a storage yard Is it only storage? Earthwork, 1 means storage area Stockpile only Earthwork, 0 means storage area Not only storage Class earthwork; Mixed field stockpile variables ——Indicates from the excavation site To the stockpile Mixed stockpile Earthwork volume; Classification field stockpile variables ——Indicates from the excavation site To the stockpile Classified storage Earthwork volume; Mixed field return variable ——Indicates the mixed stockpile storage area To the excavation site Return Earthwork volume; Classification field return variables ——Indicates the stockpile from classified stockpile To the excavation site Return Earthwork volume, in, and is a binary decision variable, , , as well as are all non-negative continuous decision variables.

3. The method for stockpiling and allocating earth and stone based on return transportation demand according to claim 2 is characterized in that: In step S2, a first constraint formula is established based on the storage yard type. , which means that when the storage yard is set as a classified storage yard, it can and only can classify and store one type of earth and stone; when the storage yard is set as a mixed storage yard, it cannot classify and store only one type of earth and stone.

4. The earthwork storage and allocation method based on return transportation demand according to claim 2 is characterized in that: In step S2, based on the storage yard type variable in the decision variable and stockpile type variables The actual value range of the second constraint is established and the third constraint .

5. The method for stockpiling and allocating earth and stone based on return transportation demand according to claim 2 is characterized in that: In step S2, a fourth constraint formula is established based on the earthwork storage demand and the return demand. and the fifth constraint , which are used to ensure that the sum of the earth and stone volume transported from the excavation site to the classification stockpile and the mixed stockpile meets the excavation demand, and the sum of the earth and stone volume transported back from the classification stockpile and the mixed stockpile to the excavation site meets the return transportation demand.

6. The method for stockpiling and allocating earth and stone based on return transportation demand according to claim 2 is characterized in that: In step S2, the sixth constraint is established , used to ensure that the amount of earth and stone returned from the mixed stockpile is not greater than the amount stored; and Seventh Constraint , used to ensure that the amount of earth and stone returned from the classified stockpile is not greater than the stockpile amount.

7. The method for stockpiling and allocating earth and stone based on return transportation demand according to claim 2 is characterized in that: In step S2, based on the mixed field stockpile variable in the decision variable , Classification field stockpile variables , mixed field return variables and the classification field return variables The actual value range of the eighth constraint is established , the ninth constraint , the tenth constraint , the eleventh constraint .

8. The method for stockpiling and allocating earth and stone based on return transportation demand according to claim 2 is characterized in that: In step S2, based on the storage yard capacity, the twelfth constraint formula is established , used to ensure that the total amount of earth and rock transported into the mixed stockpile does not exceed its design capacity, and the thirteenth constraint , used to ensure that the amount of a specific type of earth and rock transported into a classification stockpile does not exceed its design capacity.

9. The method for stockpiling and allocating earth and stone based on return transportation demand according to claim 2 is characterized in that: In step S3, the first measurement objective is to minimize the total transportation distance during the earthwork storage and return transportation process. ,in, express Excavation site and Transportation distances between stockpiles; the second metric is to minimize the amount of earth and rock excavated and transported back from the mixed stockpile , introduce a trade-off coefficient between the first measurement objective and the second measurement objective , establish comprehensive measurement goals ,Further combining the comprehensive measurement objectives with the ,associated constraints of decision variables, a mixed integer linear programming model ,is constructed.

10. The earthwork storage and allocation method based on return transportation demand according to claim 9 is characterized in that: in, The trade-off coefficient The value of is 0.5.

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