Efficient reinforcement treatment method for uneven slag storage yard foundation

Abstract

The invention discloses an efficient reinforcement treatment method for a foundation of a non-uniform slag storage yard, relates to the technical field of foundation treatment, and aims at solving the technical problems that under the complex geology and limited conditions, the reinforcement efficiency of the foundation of the non-uniform slag storage yard is low, differential settlement is difficult to control, and the utilization rate of slag resources is low. The method comprises the following steps: 1) site investigation and slag sampling; 2) evaluating and classifying the characteristics of the slag engineering; 3) carrying out site partitioning based on functional requirements and geological conditions; (4) multi-process synergistic reinforcement treatment is conducted, hydraulic tamping is used as the core, and slag grading backfilling is combined; by means of the method, the characteristic value of the bearing capacity of the storage yard foundation can be larger than or equal to 120 kPa, post-construction settlement is smaller than or equal to 50 cm, efficient reutilization of slag resources is achieved, the construction period is shortened, the engineering cost is reduced, and the method is suitable for engineering scenes such as port heavy box storage yards with high requirements for the bearing capacity and settlement control of the foundation.

Description

Technical Field

[0001] This invention belongs to the field of foundation treatment technology, specifically relating to an efficient reinforcement method for the foundation of a non-uniform slag heap site. Background Technology

[0002] With the advancement of the new infrastructure strategy and the surge in port logistics demand, port storage yards are gradually transforming from empty container storage to loaded container storage, imposing stringent requirements on foundation bearing capacity (≥120kPa) and post-construction settlement (≤50cm). Currently, commonly used reinforcement methods for coastal soft soil foundation storage yards include replacement, vacuum preloading, and dynamic compaction. However, for complex geological conditions such as deep soft clay, silt interlayers, and uneven surface slag accumulation, existing technologies have the following shortcomings: Low reinforcement efficiency: Traditional dynamic compaction method has limited reinforcement depth for deep soft clay, only 3m to 5m, requiring multiple backfillings and a construction period of 12 to 18 months; vacuum preloading method requires the laying of a sealing membrane, which is affected by the damage of sharp particles of slag, resulting in unstable reinforcement effect.

[0003] Differential settlement is difficult to control: The slag particles in the site are unevenly distributed, with a mud content of 5% to 30%, and the distribution of soft clay varies spatially. A single process can easily lead to a settlement difference of more than 15cm in different areas, causing the risk of ground cracking and container overturning in the storage yard.

[0004] Waste of slag: Existing projects often treat surface slag as construction waste, which not only increases disposal costs but also occupies land resources, which is inconsistent with the concept of green construction.

[0005] Therefore, developing a foundation treatment method that takes into account "efficient reinforcement, differential settlement control, and slag reuse" has become the key to solving the foundation problems of port container stacking sites. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for efficient reinforcement of the foundation of a non-uniform slag dump site, comprising the following steps: S1, Site Investigation and Slag Sampling: Conduct a full-area geological investigation of the uneven slag pile site to determine the distribution range of deep soft clay, the thickness and burial depth of silt interlayers, and collect slag samples according to the grid, with each sample weighing no less than 10kg. S2, Evaluation and classification of engineering characteristics of quarry slag: Indoor tests were conducted on the collected quarry slag samples to test particle size distribution, compaction degree and bearing capacity. Combined with the results of on-site density tests, the quarry slag was classified into first-level applicable filler, second-level improved filler and waste filler. S3, Site Zoning: Based on the functional requirements of the storage yard and the results of geological survey, the site is divided into different areas, and the foundation bearing capacity and settlement control standards of each area are clearly defined. S4, Multi-process collaborative reinforcement treatment: Corresponding processes are adopted for different zones, with hydraulic compaction as the core, combined with graded backfilling of slag. S5, In-situ testing and settlement dynamic monitoring: After each round of compaction and backfilling, in-situ testing is carried out at the specified density, and monitoring equipment is deployed to carry out settlement monitoring. S6, Dynamic adjustment of construction parameters: Based on the in-situ test results and settlement monitoring data, adjust the hydraulic compaction parameters and / or backfill material gradation until the design requirements are met.

[0007] Furthermore, in step S1, the overall geological survey is conducted using a combination of drilling and geophysical exploration. Drilling is carried out by laying out boreholes in a grid pattern, with the borehole depth reaching the stable bearing layer. Geophysical exploration uses surface wave exploration technology with a resolution of no less than 0.5m and an error of ≤5% in the survey results. The combination of drilling and geophysical exploration can achieve point-to-surface complementarity: drilling provides accurate data at specific points, while geophysical exploration provides distribution patterns on the surface, jointly constructing a macro-micro combined geological understanding system to fully restore the true situation of the distribution of deep soft soil and the uneven accumulation of surface slag in the site. While drilling alone can obtain the physical and mechanical parameters of soil layers at specific points, it is a point-based exploration that cannot cover a large area of ​​the site. It is easy to miss key information such as the distribution of local silt interlayers and abrupt changes in the burial depth of soft clay, resulting in fragmented geological understanding and an inability to reflect the overall heterogeneity of the site. On the other hand, while geophysical exploration can achieve surface exploration, quickly cover the entire area, and efficiently identify macroscopic features such as the distribution range of soft clay and changes in the thickness of quarry deposits, it cannot obtain specific physical and mechanical parameters of the soil layers. This makes it difficult to meet the precise data requirements for subsequent evaluation of quarry engineering characteristics and design of reinforcement process parameters.

[0008] Furthermore, in step S2, the primary applicable filler must meet the following requirements: a particle size distribution of ≥75% in the range of 0.075mm to 60mm, a compaction degree of ≥93%, and a light dynamic penetration test hammer count of ≥15 blows; the secondary improved filler must meet the following requirements: a particle size distribution of 50% to 75% in the range of 0.075mm to 60mm, a compaction degree of 85% to 92%, and a light dynamic penetration test hammer count of 10 to 14 blows. The secondary improved filler is used after mixing the corresponding slag with 5wt% to 8wt% crushed stone; the waste filler must meet the following requirements: a particle size distribution of <50% in the range of 0.075mm to 60mm, a compaction degree of <85%, and a light dynamic penetration test hammer count of <10 blows. The grading standard accurately distinguishes the performance levels of quarry slag using three key indicators: particle size distribution, compaction degree, and number of blows. Primary slag is directly reused, secondary slag is improved and then reused, and waste slag can be further improved through crushing, screening, and mixing with crushed stone for use in temporary access roads, achieving full life-cycle utilization of quarry slag. The grading standard clarifies the performance boundaries of different slags, directly guiding the design of reinforcement process parameters: for heavy-duty box stockpiles backfilled with primary slag, a hydraulic compaction process with higher impact energy and more passes can be used to maximize the load-bearing potential of the slag; for iron transfer zones backfilled with secondary improved slag, a moderate impact energy and fewer passes can be selected to avoid over-compaction and increased costs. Without a clear grading standard, mismatches could occur, such as using low-strength processes with high-quality slag or high-strength processes with low-quality slag. The grading standard, through precise matching of slag performance with process parameters, provides a fundamental guarantee for differential settlement control.

[0009] Furthermore, the indoor test in step S2 also includes testing the compressibility coefficient of the slag; the compressibility coefficient A of the primary applicable packing is <0.2 MPa. -1 The compression coefficient B of the secondary modified packing is less than 0.3 MPa. -1 .

[0010] Furthermore, in step S3, if the site includes a container yard and a transfer rail connection area, the container yard area corresponds to a deep soft clay burial depth of <5m, a foundation bearing capacity requirement of ≥130kPa, a post-construction settlement requirement of ≤45cm, and a differential settlement limit of ≤8cm; the transfer rail connection area corresponds to a deep soft clay burial depth of 5m~8m, a foundation bearing capacity requirement of ≥120kPa, a post-construction settlement requirement of ≤50cm, and a differential settlement limit of ≤10cm.

[0011] Furthermore, in step S4, a hydraulic compaction combined with primary suitable fill material is used for backfilling in the heavy container storage area. The hydraulic compaction equipment used has an impact energy of 1800 kN·m to 2200 kN·m, and is compacted in 3 to 4 passes. After each pass, primary suitable fill material is backfilled, with a backfill thickness controlled at 0.8 m to 1.2 m. For the transfer connection area, a hydraulic compaction combined with secondary improved fill material is used for backfilling. The hydraulic compaction energy used is 1500 kN·m to 1800 kN·m, and is compacted in 2 to 3 passes. Before backfilling, the secondary improved fill material is mixed with 5% to 8% crushed stone, and the backfill thickness is controlled at 1.0 m to 1.5 m. In the heavy container storage area, the soft soil is located in the shallow layer and is more directly affected by loads, making it prone to compression deformation. Therefore, post-construction settlement must be strictly controlled. High-energy compaction (1800kN·m~2200kN·m) can effectively penetrate the surface slag and directly act on the shallow soft soil, accelerating its consolidation. Multiple compaction passes (3-4 times) gradually compact the fill material and underlying soft soil, preventing excessive energy from a single compaction pass from loosening the surface slag. A backfill thickness of 0.8m~1.2m reduces additional settlement caused by the weight of the fill material and facilitates the transfer of compaction energy to deeper layers, ultimately achieving precise post-construction settlement control. In the iron-transfer connection zone, where the soft soil is located at a deeper level, the compaction energy... The compaction energy needs to penetrate a thicker soil layer to be effective on soft soil. A compaction energy of 1500kN·m to 1800kN·m ensures that energy is transferred to the deep soft soil while avoiding excessive energy attenuation. Two to three compaction passes can balance the reinforcement effect and construction efficiency. A backfill thickness of 1.0m to 1.5m can use the weight of the fill material itself to assist in compacting the deep soft soil. At the same time, it is suitable for the characteristics of dynamic loads in this area, reducing instantaneous settlement caused by the passage of transportation equipment, and meeting the standard of post-construction settlement ≤50cm. The container yard area employs high-energy compaction, multiple compaction passes, high-quality fill material, and a thinner backfill layer to achieve higher uniformity of foundation compaction, avoid localized insufficient compaction, and strictly control settlement (≤45cm) to reduce settlement differences within the area and with the transfer rail connection zone. The transfer rail connection zone uses medium-energy compaction, fewer compaction passes, improved fill material, and a thicker backfill layer. While meeting its own settlement standard (≤50cm), parameter optimization ensures that the settlement difference between the two types of areas is controlled within a reasonable range. If uniform process parameters are used, such as high-energy compaction for both types of areas, it will lead to over-reinforcement of the transfer rail connection zone or insufficient reinforcement of the container yard area, exacerbating differential settlement and causing problems such as ground cracking and equipment failure.

[0012] Furthermore, in step S4, the hydraulic compaction points are arranged in a square grid with a grid spacing of 2.5m to 3.0m and an overlap of no less than 15% between adjacent compaction points. The backfill material is spread using a grader to level it, and after leveling, it is pre-compacted 3-4 times with a vibratory roller with an excitation force of ≥300kN, and then hydraulically compacted.

[0013] Furthermore, in-situ testing in step S5 includes a plate load test and a static cone penetration test. The plate load test uses the slow sustained load method, with a maximum load not less than twice the design bearing capacity. The static cone penetration test uses a single-bridge probe, with a test depth to the underlying soft clay layer, requiring a cone tip resistance Q. c ≥2.5MPa; Settlement monitoring is carried out using stratified settlement gauges and total stations, with a monitoring frequency of once a week for the first 3 months and once a month thereafter.

[0014] Furthermore, in step S6, if the bearing capacity does not reach the design value, increase the number of hydraulic tamping passes by 1 to 2 or increase the tamping energy by 10% to 15%; if the differential settlement exceeds the limit, adjust the backfill material gradation or locally increase the compaction depth; if the settlement rate is >2mm / day, suspend compaction and let it stand for 3 to 5 days until the settlement stabilizes before continuing construction.

[0015] Furthermore, in step S2, after the waste packing material is crushed and screened to remove particles with a diameter >60mm, it is mixed with 10%~12% crushed stone for improvement and can be reused as temporary access road packing material.

[0016] The beneficial effects of this invention are: (1) Improve the bearing capacity and settlement control accuracy of the foundation. Through multi-process collaboration, dynamic monitoring and feedback adjustment, the characteristic value of the bearing capacity of the foundation is ≥120kPa, the post-construction settlement is ≤50cm, and the differential settlement is controlled within 8–10cm, which meets the high standard of use requirements of the port container yard.

[0017] (2) To achieve efficient reuse of slag resources and establish a scientific slag classification and evaluation system: Level 1 is applicable, Level 2 is improved and waste is reused, and the slag that originally needed to be transported is transformed into usable filler, significantly improving the utilization rate and reducing the cost of purchasing filler and waste disposal.

[0018] (3) Adapt to complex geological conditions, combine drilling and geophysical exploration technologies to accurately identify the distribution of soft clay and the accumulation of slag, and customize differentiated construction parameters for different zones: the heavy box storage area and the iron transfer connection area, effectively addressing complex geological challenges such as deep soft soil and uneven slag.

[0019] (4) By reusing slag on-site, the cost of purchasing filler and transporting waste is reduced, saving material and transportation costs. The high-efficiency construction process with hydraulic compaction as the core is adopted, combined with a dynamic adjustment mechanism to avoid repeated construction and significantly shorten the construction period; the refined settlement control and long-term monitoring system reduces the risk of post-construction settlement and reduces maintenance costs such as ground cracking and equipment damage.

[0020] (5) Provide standardized construction processes, from surveying, evaluation, zoning, construction to monitoring, forming a complete and replicable foundation treatment technology system applicable to various port, logistics yard, coastal soft soil and other engineering scenarios.

[0021] (6) It has strong engineering adaptability, flexible and adjustable methods, and can dynamically optimize construction parameters according to specific geological conditions and functional requirements. It has broad engineering applicability and promotion prospects. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described in conjunction with specific embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] This embodiment takes the container yard project in the tailings area of ​​the Meishan Port Phase II project of China Communications Construction Guangzhou Dredging Co., Ltd. as an example to illustrate the implementation process of the present invention in detail: Step 1: Site investigation and slag sampling A comprehensive exploration was conducted using a combination of drilling and geophysical methods. Drilling: Drill holes in a 100m×100m grid, drilling to the stable bearing layer, collecting samples of soft clay, silt interlayers and slag, and recording the burial depth, thickness and physical and mechanical parameters of each soil layer, such as natural water content and void ratio. Geophysical exploration: Surface wave exploration technology is used to conduct non-destructive testing on the distribution area of ​​soft clay, with a resolution of not less than 0.5m, ensuring full coverage of the exploration results and an error of ≤5%; Slag sampling: Collect slag samples within a 5m radius around the borehole. Each sample should weigh ≥10kg to avoid sampling bias.

[0024] Step 2: Evaluation and Classification of Engineering Characteristics of Slag Quarry Precise classification of slag is achieved by combining indoor experiments with field tests. Indoor tests: Particle size distribution analysis was performed in the laboratory using sieving method, with a particle size range of 0.075 mm to 60 mm. Compaction tests were also conducted to determine the optimum moisture content ω. opt =12%~15%, maximum dry density ρ dmax =1.8~2.0g / cm 3 Compression test, measuring the compression coefficient; Light dynamic penetration test, measuring the number of blows. On-site testing: The density of the quarry was measured using the ring cutter method, and the compaction degree was calculated as: on-site dry density / maximum dry density × 100%; Classification criteria: Classification shall be carried out according to Table 1. Class I filler material shall be used directly for backfilling of the core area. Class II improved filler material shall be used after being mixed with crushed stone. Waste filler material shall be improved and used for temporary projects.

[0025] Table 1 Classification Standards for Waste

[0026] Step 3: Site Zoning Based on the functional requirements of the Meishan Port Phase II project's storage yard, the site is divided into two core areas: the Meidong-Meibei rail transfer connection area to the north and the Meidong container storage yard area to the south, according to the survey results. The zoning standards and design requirements are shown in Table 2. Table 2 Site Zoning and Design Requirements

[0027] Step 4: Multi-process collaborative reinforcement treatment A combined process of hydraulic compaction and staged backfilling was adopted, with parameters optimized for different zones: Equipment selection: YTH series hydraulic compactors are selected, with YTH-2200 (impact energy 2200kN·m) for Zone I and YTH-1800 (impact energy 1800kN·m) for Zone II. Compaction point layout: square grid, spacing 2.5m (Zone I) and 3.0m (Zone II), overlap 15%, to avoid missed compaction; Backfilling and compaction process: Surface clearing: Remove weeds and humus from the surface of the site; Pre-compaction: Use a 300kN vibratory roller for three passes to achieve a compaction degree of 85%; Backfill: Zone I is backfilled with primary filler material, 1.0m thick; Zone II is backfilled with improved secondary filler material, 1.2m thick; leveled with a grader, flatness ≤5cm / 10m). Hydraulic compaction: Ⅰ Distinguish between 4 compaction passes, with the first and second passes being full compaction and the third and fourth passes being spot compaction; Ⅱ Distinguish between 3 compaction passes, with the first and second passes being full compaction and the third pass being spot compaction. After each compaction pass, test the ground settlement and control the single settlement to ≤5cm. Filling: If depressions appear on the ground surface after compaction, and the depth is greater than 3cm, fill them with filler of the same grade to the design elevation.

[0028] Step 5: In-situ testing and dynamic settlement monitoring In-situ testing: After each round of compaction and backfilling, test at 200m intervals. 2 / Set up test points: Plate load test: The slow sustained load method was adopted, with loading levels of 20 kPa / level. The stability criterion was settlement ≤0.1 mm within 1 hour. The proportional limit load was taken as the characteristic value of bearing capacity. Static cone penetration test: A single-bridge probe was used, and the test depth was extended to the underlying soft clay layer (≥5m). The cone tip resistance Q was recorded. c Q is required c ≥2.5MPa; Settlement monitoring: Deep monitoring: Three stratified settlement meters were deployed in each of Zones I and II, with a monitoring depth of 5m (Zone I) and 8m (Zone II) and a resolution of 0.1mm; Surface monitoring: Monitoring points were set up using a total station in a 50m×50m grid, with an elevation measurement accuracy of ±2mm; Monitoring frequency: once a week for the first 3 months, once a month thereafter, and continue monitoring until 6 months after construction. Stop when the settlement rate is ≤0.5mm / month.

[0029] Step 6: Dynamic adjustment of construction parameters Optimize and adjust construction parameters based on monitoring data: If the load-bearing capacity is insufficient (< design value): If Q c <2.5MPa, add one more tamping pass (Zone I) or increase tamping energy by 10% (Zone II); Differential settlement exceeding the limit: If the settlement difference between adjacent monitoring points in Zone I is >8cm, add one more round of compaction in the local area; if it is >10cm in Zone II, adjust the backfill material gradation and increase the crushed stone content by 2wt%. If the settlement rate is too fast (>2mm / day): Stop compaction, let it stand for 3-5 days, and continue construction after the settlement stabilizes.

[0030] Finally, the method described in this application is merely a preferred embodiment and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for efficient reinforcement of the foundation of a non-uniform slag dump site, characterized in that, Includes the following steps: S1, Site Investigation and Slag Sampling: Conduct a full-area geological investigation of the uneven slag pile site to determine the distribution range of deep soft clay, the thickness and burial depth of silt interlayers, and collect slag samples according to the grid, with each sample weighing no less than 10kg. S2, Evaluation and classification of engineering characteristics of quarry slag: Indoor tests were conducted on the collected quarry slag samples to test particle size distribution, compaction degree and bearing capacity. Combined with the results of on-site density tests, the quarry slag was classified into first-level applicable filler, second-level improved filler and waste filler. S3, Site Zoning: Based on the functional requirements of the storage yard and the results of geological survey, the site is divided into different areas, and the foundation bearing capacity and settlement control standards of each area are clearly defined. S4, Multi-process collaborative reinforcement treatment: Corresponding processes are adopted for different zones, with hydraulic compaction as the core, combined with graded backfilling of slag. S5, In-situ testing and settlement dynamic monitoring: After each round of compaction and backfilling, in-situ testing is carried out at the specified density, and monitoring equipment is deployed to carry out settlement monitoring. S6, Dynamic adjustment of construction parameters: Based on the in-situ test results and settlement monitoring data, adjust the hydraulic compaction parameters and / or backfill material gradation until the design requirements are met.

2. The method according to claim 1, characterized in that, In step S1, the geological survey of the entire area is carried out by a combination of drilling and geophysical exploration. Drilling is carried out by laying out boreholes in a grid and drilling to the stable bearing layer. Geophysical exploration adopts surface wave exploration technology with a resolution of not less than 0.5m and an error of ≤5% in the survey results.

3. The method according to claim 1, characterized in that, In step S2, the primary filler must meet the following requirements: a particle size distribution of ≥75% in the range of 0.075mm to 60mm, a compaction degree of ≥93%, and a light dynamic penetration test hammer count of ≥15 blows. The secondary improved filler must meet the following requirements: a particle size distribution of 50% to 75% in the range of 0.075mm to 60mm, a compaction degree of 85% to 92%, and a light dynamic penetration test hammer count of 10 to 14 blows. The secondary improved filler is used after mixing the corresponding slag with 5wt% to 8wt% crushed stone. The waste filler must meet the following requirements: a particle size distribution of <50% in the range of 0.075mm to 60mm, a compaction degree of <85%, and a light dynamic penetration test hammer count of <10 blows.

4. The method according to claim 1, characterized in that, Step S2, the indoor test also includes testing the compressibility coefficient of the slag; the compressibility coefficient A for primary applicable packing is <0.2 MPa. -1 The compression coefficient B of the secondary modified packing is less than 0.3 MPa. -1 .

5. The method according to claim 1, characterized in that, In step S3, if the site includes a container yard and a transfer rail connection area, the container yard area has a corresponding deep soft clay burial depth of <5m, a foundation bearing capacity requirement of ≥130kPa, a post-construction settlement requirement of ≤45cm, and a differential settlement limit of ≤8cm; the transfer rail connection area has a corresponding deep soft clay burial depth of 5m~8m, a foundation bearing capacity requirement of ≥120kPa, a post-construction settlement requirement of ≤50cm, and a differential settlement limit of ≤10cm.

6. The method according to claim 1, characterized in that, In step S4, a hydraulic compaction combined with primary suitable fill material is used for backfilling in the heavy container storage area. The hydraulic compaction equipment is selected with a compaction energy of 1800kN·m to 2200kN·m, and compaction is carried out in 3 to 4 passes. After each pass of compaction, primary suitable fill material is backfilled, and the backfill thickness is controlled at 0.8m to 1.2m. For the transfer connection area, a hydraulic compaction combined with secondary improved fill material is used for backfilling. The hydraulic compaction energy is selected with 1500kN·m to 1800kN·m, and compaction is carried out in 2 to 3 passes. Before backfilling, the secondary improved fill material is mixed with 5% to 8% crushed stone, and the backfill thickness is controlled at 1.0m to 1.5m.

7. The method according to claim 1, characterized in that, In step S4, the hydraulic compaction points are arranged in a square grid with a grid spacing of 2.5m to 3.0m and an overlap of no less than 15% between adjacent compaction points. The backfill material is spread by a grader to level it, and after leveling, it is pre-compacted 3-4 times with a vibratory roller with an excitation force of ≥300kN, and then hydraulic compaction is carried out.

8. The method according to claim 1, characterized in that, Step S5 involves in-situ testing including a plate load test and a static cone penetration test. The plate load test uses the slow sustained load method, with a maximum load not less than twice the design bearing capacity. The static cone penetration test uses a single-bridge probe, with a test depth extending to the underlying soft clay layer, requiring a cone tip resistance Q. c ≥2.5MPa; Settlement monitoring is carried out using stratified settlement gauges and total stations, with a monitoring frequency of once a week for the first 3 months and once a month thereafter.

9. The method according to claim 1, characterized in that, If the bearing capacity does not reach the design value in step S6, increase the number of hydraulic tamping passes by 1 to 2 or increase the tamping energy by 10% to 15%; if the differential settlement exceeds the limit, adjust the backfill material gradation or locally increase the compaction depth; if the settlement rate is >2mm / day, suspend compaction and let it stand for 3 to 5 days until the settlement stabilizes before continuing construction.

10. The method according to claim 1, characterized in that, In step S2, the waste packing material is crushed and screened to remove particles with a diameter >60mm. After being improved by mixing with 10%~12% crushed stone, it can be reused as a temporary access road packing material.

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