Earthwork backfilling construction method

Abstract

The invention discloses an earthwork backfilling construction method. The earthwork backfilling construction method solves the problem that the project quality is difficult to guarantee due to inaccurate water content control and unstable compaction quality in traditional backfilling operation. The method comprises the steps that a backfill area is divided into backfill areas with the thickness of 30-50 cm in a layered mode; compacting for 3-5 times by adopting a vibratory roller; the water content of the soil body is regulated and controlled to be 95%-105% of the optimal water content through an atomization spraying system, and the spraying flow is controlled to be 2-5 L / m < 2 > * min; the soil body with the water content higher than 110% is adjusted by spreading and airing or mixing with improved soil with the water content smaller than or equal to 8%; unqualified areas are automatically marked through real-time compaction degree monitoring, and a pressure supplementing instruction is triggered. The method is mainly used for earthwork backfilling construction of constructional engineering, road engineering and the like, the uniformity and compactness of backfilled soil can be remarkably improved, and it is ensured that the engineering quality meets the design requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering construction, in particular to an earth backfill construction method. Background Art

[0002] In earthwork backfill construction, moisture content control and compaction quality are key factors affecting the stability of the project. The existing technology has the following problems and shortcomings in practical application:

[0003] (1) Insufficient precision in moisture content control

[0004] Traditional methods for adjusting moisture content rely primarily on manual judgment and lack quantitative control standards. During spraying operations, wind speed often affects the spraying process, resulting in uneven spraying and localized moisture content exceeding the optimal range. Especially when wind speeds exceed level 3, atomized water droplets are easily dispersed, resulting in uneven moisture distribution. Furthermore, existing spraying systems lack real-time feedback mechanisms, making it difficult to dynamically adjust operating parameters based on environmental changes.

[0005] (2) Poor soil adaptability

[0006] Conventional construction methods apply a uniform moisture content control standard to all soil types, failing to fully consider the impact of varying soil qualities. For example, sandy soils and clay soils exhibit significant differences in water permeability and retention, yet existing technologies lack differentiated control parameters. For gravelly soils, existing methods use only total gravel content as a control metric, ignoring the varying effects of different gravel sizes on compaction properties.

[0007] (3) Unstable compaction quality

[0008] Traditional methods for determining the number of compaction passes rely primarily on fixed standards or field experience, and are unable to dynamically adjust to real-time moisture content changes. When soil moisture content deviates from the optimal value, continuing to compact according to the original number of passes can easily lead to under- or overcompaction. Existing monitoring technologies often rely on single-point sampling, which makes it difficult to fully reflect the compaction status of the working surface and can easily miss areas of substandard quality.

[0009] (4) Rough control of standing time

[0010] Existing technologies use a fixed setting for the post-spray rest time, failing to consider the impact of ambient temperature and humidity on moisture migration. Under high-temperature, dry conditions, rapid evaporation of surface moisture leads to an increased moisture gradient; under low-temperature, high-humidity conditions, slow water penetration easily causes water accumulation in the upper layers. This static control method makes it difficult to ensure uniform moisture distribution within the soil.

[0011] (5) Lack of parameter coordination

[0012] Key parameters such as moisture content testing, compaction pass determination, and gravel content assessment were independently controlled, lacking system-level coordination. For example, the correlation between moisture content deviation and compaction pass number was not quantified, and gravel content testing and k-value calculation were not well aligned. This fragmented control model resulted in suboptimal construction parameter combinations.

[0013] Therefore, it is urgent to provide an earth backfill construction method that can solve the above-mentioned technical problems. Summary of the Invention

[0014] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0015] One purpose of the present invention is to solve the problem of unstable compaction quality caused by inaccurate moisture content control during earth backfill construction. Traditional methods rely on manual experience to judge the moisture content, which makes it difficult to accurately control it to the optimal moisture content range (95%-105%), resulting in over-dry or over-wet areas affecting the compaction effect. At the same time, the conventional compaction number is fixed and cannot adapt to the actual needs of soils with different moisture contents. The present invention achieves precise control of moisture content and real-time feedback of compaction quality by establishing a collaborative mechanism between a dynamic moisture content control system and intelligent compaction monitoring.

[0016] One objective of the present invention is to address the problem of uneven spraying caused by wind in atomizing spray systems. Conventional spraying operations experience mist drift when wind speeds exceed 3m / s, resulting in uneven water distribution. The present invention ensures spray uniformity through weather forecasting, real-time wind speed monitoring, and a zoned and segmented spraying strategy. Intermittent spraying combined with a rest period effectively prevents airflow interference and increases water utilization by over 35%.

[0017] One objective of the present invention is to address the mismatch between the proportion of improved soil and the soil quality. Existing technologies use a fixed blending ratio (10-20%), failing to account for the varying requirements of soils with varying plasticity indexes. The present invention adjusts the blending ratio (10-20%) and mixing time based on the plasticity index (IP), improving the moisture content adjustment accuracy of silty soils and clay soils by 40% and 60%, respectively.

[0018] One purpose of the present invention is to solve the problem of mismatch between spray flow parameters and soil permeability characteristics. Conventional methods use the same flow rate for sand, silt, and clay, resulting in excessive water infiltration in sand or surface runoff in clay. The present invention matches the soil type with a differentiated flow rate (1-5L / m 2 ·min) and standing time, so that the moisture content of various soils can be increased to above 95%.

[0019] One objective of this invention is to address the disconnect between compaction passes and real-time moisture content. Traditional fixed pass counts cannot adapt to moisture content fluctuations, easily leading to under- or over-compaction. This invention establishes a dynamic calculation model (N = N0 + k·|w - wopt|) that automatically adjusts the pass count based on moisture content deviations, improving compaction uniformity by 30%.

[0020] One objective of this invention is to address the issue of uniform moisture content deviation thresholds. Existing standards use the same tolerance for sand and clay, ignoring their differences in permeability. This invention establishes differentiated soil-quality thresholds (±7% for sand and ±3% for clay) to avoid over-regulation of sand and under-regulation of clay.

[0021] One objective of this invention is to address the problem of localized excess moisture caused by moisture migration during compaction. Conventional methods struggle to detect vibration-induced moisture redistribution in a timely manner. This invention, through gridded secondary scanning and area grading, increases the recognition rate of localized issues from 70% to 98% and reduces overall downtime by 50%.

[0022] One objective of the present invention is to address the problem of empirically setting the k value. Existing methods fail to consider the influence of gravel content and particle size distribution. Through indoor and outdoor testing, the present invention establishes a calculation model for k = α(Ip / 17) + β(G / 30) + γ, and incorporates a graded gravel content test to control the k value calculation error within ±8%.

[0023] One of the objectives of the present invention is to solve the problem of inaccurate gravel content assessment. Traditional methods only count the total gravel content and ignore the differences in particle size distribution. The present invention calculates the effective gravel content G by weighting fine gravel (5-20 mm) and coarse gravel (20-40 mm) by classification. e , and adding the particle size correction term δ, the compaction degree prediction accuracy of gravel-containing soil is improved by 25%.

[0024] One objective of this invention is to address the issue of poor environmental adaptability of resting time. Fixed resting time can easily lead to uneven moisture distribution under extreme temperatures and humidities. This invention dynamically adjusts resting time (shortening it by 30% or extending it by 40%) by monitoring surface temperature and wind speed, and combines this with double-layer moisture content verification to keep the moisture gradient within 1.5%.

[0025] An object of the present invention is to provide an earth backfill construction method comprising the following steps:

[0026] Layered backfill: Divide the area to be backfilled into at least two layers of backfill areas. The thickness of each layer of backfill area is 30-50cm. Use a vibratory roller to compact each layer of backfill soil 3-5 times.

[0027] Dynamic control of moisture content: Before backfilling each layer, the moisture content of the backfill soil is tested; if the moisture content is lower than 90% of the optimal moisture content, the atomizing spray system is used for uniform spraying and adjusted to 95%-105% of the optimal moisture content. The flow control range of the atomizing spray system is 2-5L / m 2 min; if the moisture content is higher than 110% of the optimum moisture content, the soil is spread and aired, or pre-dried improved soil is added, with the improved soil having a moisture content of ≤8% and a mixing ratio of 10-20%, so that the mixed soil moisture content reaches 95%-105% of the optimum moisture content; the optimum moisture content is determined by a modified Protz compaction test with a hammer weight of 4.5kg and a drop distance of 457mm;

[0028] Intelligent compaction monitoring: Real-time monitoring of the compaction degree of each layer of backfill soil. If the compaction degree does not meet the design requirements, the area will be automatically marked and the re-compaction instruction will be triggered.

[0029] Preferably, in the earth backfill construction method, the operation process of the atomizing spray system includes the following control method:

[0030] Obtain meteorological data before construction. When the wind speed forecast is greater than level 3, the moisture content adjustment operation will be automatically delayed.

[0031] When spraying, monitor the wind speed on the working surface in real time and stop spraying immediately when the instantaneous wind speed is greater than 3m / s;

[0032] A zoned and segmented spraying strategy was adopted, dividing the area to be treated into 5m×5m grid units. After spraying each unit, it was left to stand for 2 minutes before proceeding to the adjacent unit.

[0033] Within 30 minutes after spraying, conduct a secondary moisture content sampling test on the treated area with a sampling ratio of 10%. When the moisture content deviation is greater than ±1.5%, start compensatory spraying.

[0034] Preferably, in the earth backfill construction method, the proportion of the pre-dried improved soil added is dynamically adjusted according to the original soil plasticity index Ip:

[0035] When the original soil plasticity index Ip≤7%, the incorporation ratio is 10-12%; when 7%<Ip≤17%, the incorporation ratio is 15-18%; when Ip>17%, the incorporation ratio is 18-20%, and the mixing time after incorporation is extended to 1.5 times that of conventional soil.

[0036] Preferably, in the earth backfill construction method, the flow control parameters of the atomizing spray system are dynamically adjusted according to the soil type:

[0037] For sandy soil, particle size> 0.075mm particle content ≥ 85%, use 3-5L / m 2·min high flow rate spraying, the standard value of the static time after spraying is 5min; for silt, 0.075mm≥particle size>0.005mm particle content≥50%, use 2-3L / m 2 ·min medium flow spray, the standard value of the static time after spraying is 10-15min; for clay, particle size ≤ 0.005mm particle content ≥ 30%, use 1-2L / m 2 For low-flow spraying of 100-200ml, the benchmark value of the standing time after spraying is 20-30min.

[0038] Preferably, in the earth backfill construction method, the number of compaction passes is dynamically adjusted according to the real-time moisture content detection result, specifically satisfying the following relationship:

[0039] N=N0+k·|w-wopt|,

[0040] Where: N is the actual number of compaction passes; N0 is the benchmark number of compaction passes, which is 3-5 times; k is the soil correction coefficient; w is the measured moisture content; wopt is the optimal moisture content; when |w-wopt| is greater than the set dynamic threshold of moisture content deviation, the moisture content is adjusted to 95%-105% of the optimal moisture content before compaction.

[0041] Preferably, in the earth backfill construction method, the dynamic threshold of moisture content deviation is set according to the soil type, and the setting method is as follows:

[0042] For sandy soil, particle size > 0.075 mm, particle content ≥ 85%, and the dynamic threshold of moisture content deviation is set to ± 7%;

[0043] For silt, 0.075 mm ≥ particle size > 0.005 mm, particle content ≥ 50%, and the dynamic threshold of moisture content deviation is set to ±5%;

[0044] For clay, the particle size is ≤ 0.005 mm, the particle content is ≥ 30%, and the dynamic threshold of moisture content deviation is set to ± 3%.

[0045] Preferably, in the earth backfill construction method, the following real-time monitoring and dynamic adjustment measures are implemented during the compaction process, and the monitoring and dynamic adjustment measures include:

[0046] a) Dynamic tracking of moisture content: After each compaction operation, the working surface is scanned for moisture content twice in a grid format, with a grid spacing of ≤1.5m;

[0047] b) Local over-limit processing: When it is detected that the moisture content deviation in a local area |w-wopt| exceeds the dynamic threshold of the moisture content deviation, a hierarchical processing is performed:

[0048] If the area exceeding the limit is less than 5%, mark the area and skip further compaction until the entire area meets the standard;

[0049] If the excess area is ≥5%, construction will be suspended immediately and regional moisture content adjustment will be initiated.

[0050] Preferably, in the earth backfill construction method, the soil correction coefficient k is determined by the following method:

[0051] Step (1) Indoor model test

[0052] Based on actual engineering soil samples, test groups were prepared with gravel contents of 0%, 10%, 20%, and 30%. Each group of soil samples was set at seven gradient moisture contents within the range of ±5% of the optimal moisture content. Compaction was performed using a standard compactor, and a three-dimensional relationship database was established between the moisture content deviation |w - wopt|, the number of compaction passes N, and the compaction degree K.

[0053] Step (2) On-site calibration test

[0054] Select typical areas on the working surface and conduct pressure tests based on field soil samples with gravel contents of 0%, 10%, 20%, and 30%; collect compaction energy and settlement data in real time;

[0055] Step (3) Dynamic k value calculation

[0056] k=α·(Ip / 17)+β·(G / 30)+γ

[0057] Where: Ip is the plasticity index (%), G is the gravel content (%), α, β, and γ are coefficients fitted by the least squares method, where α∈[0.8,1.2], β∈[-0.3,-0.1], and γ∈[0.2,0.5];

[0058] Step (4) Intelligent update mechanism

[0059] Every 1000m completed 2 After construction, new data is automatically collected to optimize the coefficients α, β, and γ.

[0060] Preferably, in the earth backfill construction method, the gravel content G is determined taking into account the gravel particle size distribution, and specifically the k value is calculated by correcting the following method:

[0061] Step (1) Particle size classification detection

[0062] The soil samples were analyzed on site and divided into fine gravel group and coarse gravel group according to particle size. The particle size of the fine gravel group is 5-20mm, and the particle size of the coarse gravel group is 20-40mm.

[0063] Calculate the effective gravel content G of the on-site soil sample e=0.7G1+0.3G2, G1 is the gravel content of the fine gravel group, G2 is the gravel content of the coarse gravel group;

[0064] Step (2) Double correction of k value

[0065] In the calculation formula of the k value, the gravel content G is replaced by the effective gravel content G e ; Add particle size correction term δ, which takes effect when G2 / G1>1, δ=0.1×(G2 / G1);

[0066] The calculation formula of the corrected k value is k=α·(Ip / 17)+β·(G e / 30)+γ+δ.

[0067] Preferably, in the earth backfill construction method, the method for controlling the standing time comprises the following steps:

[0068] Step (1) Environmental monitoring stage

[0069] Real-time monitoring of the following parameters: surface soil temperature, measuring depth 0-5cm; ambient wind speed, 1m above the ground;

[0070] Step (2) Dynamic Adjustment Stage

[0071] When the surface soil temperature is greater than 35°C and the wind speed is greater than 2m / s, the standing time is shortened by 30% based on the standing time benchmark value; when the surface soil temperature is less than 15°C and the relative humidity is greater than 75%, the standing time is extended by 40% based on the standing time benchmark value.

[0072] The present invention has at least the following beneficial effects:

[0073] (1) The present invention achieves precise coordinated control of moisture content and compaction quality during earthwork backfill construction. By establishing a closed-loop feedback mechanism combining a dynamic moisture content control system with intelligent compaction monitoring, it ensures that the soil moisture content is always maintained within the optimal range, effectively avoiding the uneven compaction problem caused by improper moisture content control in traditional construction. At the same time, the intelligent compaction monitoring system provides real-time feedback on compaction quality, significantly improving the controllability and reliability of the construction process.

[0074] (2) The present invention significantly improves the operational stability of the atomizing spray system in complex environments. By introducing weather prediction, real-time wind speed monitoring, and zoned and segmented spraying strategies, the problem of uneven spraying caused by wind interference is effectively overcome. The innovative method of combining interval spraying with a static period not only ensures uniform water distribution, but also greatly improves the efficiency of water resource utilization, making the entire spraying operation more precise and controllable.

[0075] (3) The present invention achieves intelligent matching of improved soil blending parameters. Based on a graded control mechanism based on the soil plasticity index, the blending ratio and mixing time can be automatically optimized according to different soil properties, solving the problem that traditional fixed ratios cannot adapt to a variety of soil types. This differentiated blending method significantly improves the accuracy of moisture content adjustment and creates more favorable conditions for subsequent compaction operations.

[0076] (4) The present invention establishes a precise correspondence between soil properties and spray parameters. By setting the optimal flow rate and standing time for sand, silt, and clay, respectively, the problem of uneven water penetration caused by traditional single parameter settings is effectively solved. This differentiated control strategy enables each type of soil to achieve the optimal water content, laying the foundation for high-quality compaction.

[0077] (5) The present invention establishes a dynamic correlation model between moisture content and compaction passes. This model can automatically adjust the number of compaction passes based on real-time moisture content deviations, completely overcoming the limitations of traditional fixed-pass construction. This dynamic adjustment mechanism avoids both quality risks caused by under-pressurization and energy waste caused by over-pressurization, achieving a perfect balance between construction efficiency and quality.

[0078] (6) The present invention establishes a scientific and reasonable soil moisture content deviation threshold system. By setting different allowable deviation ranges for sand, silt, and clay, the differences in the permeability characteristics of various soil types are fully considered. This refined threshold setting not only avoids unnecessary adjustment operations, but also ensures accurate control of the moisture content in key areas, greatly improving the economy and reliability of construction.

[0079] (7) This invention achieves intelligent monitoring and processing of moisture migration during compaction. The grid-based secondary scanning technology can promptly detect moisture redistribution caused by vibration, while the area-grading processing strategy enables precise location and efficient treatment of the problem. This system effectively solves the technical problem of traditional methods that make it difficult to promptly detect and address localized areas exceeding the standard.

[0080] (8) The present invention establishes a method for determining the soil correction coefficient. Through combined indoor and outdoor testing and data modeling, the k value is accurately calculated, overcoming the arbitrariness of traditional empirical values. In particular, the introduction of the gravel content parameter makes the calculation results more consistent with engineering practice, providing a reliable basis for determining the number of compaction passes.

[0081] (9) This invention significantly improves the accuracy and practicality of gravel content assessment. Through graded testing and weighted calculation of fine and coarse gravel, it accurately reflects the actual impact of different particle sizes on compaction characteristics. The added particle size correction term further optimizes the k-value calculation model, significantly improving the construction quality control level of gravel-containing soils.

[0082] (10) The present invention achieves intelligent dynamic control of the resting time. Based on the real-time monitoring and automatic adjustment mechanism of environmental parameters, the resting time can be optimized according to different climatic conditions, effectively solving the problem of poor adaptability of fixed resting time. In combination with the double-layer moisture content verification technology, it ensures the uniform distribution of moisture in the soil, providing quality assurance for subsequent construction.

[0083] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0084] The present invention is described in further detail below so that those skilled in the art can implement the invention with reference to the description.

[0085] The present invention provides an earthwork backfill construction method, comprising the following steps: layered backfilling: dividing the area to be backfilled into at least two backfill areas, each backfill area having a thickness of 30-50 cm, and using a vibratory roller to compact each backfill soil layer 3-5 times; dynamic moisture content control: before each backfilling layer, detecting the moisture content of the backfill soil; if the moisture content is lower than 90% of the optimal moisture content, evenly spraying the backfill soil through an atomizing spray system to adjust the moisture content to 95%-105% of the optimal moisture content, and the flow control range of the atomizing spray system is 2-5 L / m 2 ·min; if the moisture content is higher than 110% of the optimal moisture content, the mixed soil is spread and aired, or pre-dried improved soil is added. The moisture content of the improved soil is ≤8%, and the incorporation ratio is 10-20%, so that the moisture content of the mixed soil reaches 95%-105% of the optimal moisture content; the optimal moisture content is determined by a modified Protz compaction test with a hammer weight of 4.5kg and a drop distance of 457mm; intelligent compaction monitoring: real-time monitoring of the compaction degree of each layer of backfill soil. If the compaction degree does not meet the design requirements, the area is automatically marked and the re-compaction instruction is triggered.

[0086] The specific implementation process of the earth backfill construction method of the present invention is as follows: First, carry out on-site preparation work, measure and lay out the area to be backfilled, and divide the construction area. A laser rangefinder is used to accurately control the thickness of each layer of backfill within the range of 35cm to 45cm. Before backfilling, the operator uses a portable microwave moisture content detector to detect the backfill soil, and measures according to a 2m×2m grid. It takes about 15 seconds to obtain the moisture content data at each detection point. When the detection finds that the moisture content of a certain area is lower than 92% of the optimal moisture content, the automatic atomizing spray system is started. The system is equipped with a GPS positioning function, which can accurately control the spraying range, and the spray flow rate is automatically adjusted at 2.2L / m according to the detection data. 2 min to 4.8 L / m 2·min. After spraying, let it stand for 30 minutes and test again to confirm that the moisture content has reached the optimal range of 97% to 103%. A vibratory roller is used for compaction, and the initial setting of the compaction passes is 4 times. The roller is equipped with a real-time compaction monitoring system, which collects no less than 10 compaction data per square meter through sensors installed on the steel wheel. When the system identifies that the compaction degree of a certain place is lower than 95% of the design value, it automatically marks the location on the electronic map and prompts the operator to add 1 to 2 times of compaction to the area. All construction data is uploaded to the cloud platform in real time to achieve quality traceability throughout the process.

[0087] Compared with the closest prior art, the present invention has the following outstanding advantages:

[0088] Existing techniques typically use manual sampling to test moisture content, requiring more than 30 minutes of drying time for each sample, resulting in low testing frequency and delayed data. However, the real-time testing technology of this invention continuously provides moisture content data during construction, ensuring timely control.

[0089] Traditional spraying methods mostly use manual handheld water pipes, which are not only inefficient but also unable to accurately control the amount of water. The automated spraying system of the present invention achieves quantitative and accurate water supply, avoiding the problem of excessive or insufficient water.

[0090] Conventional compaction operations often use a fixed number of rolling passes, which cannot adapt to the unevenness of the soil layer. The intelligent compaction monitoring system of the present invention can promptly identify weak areas and carry out targeted reinforcement, ensuring uniform and reliable overall construction quality.

[0091] In the existing technology, each process is relatively independent and lacks system coordination. The present invention realizes the organic integration of moisture content detection, spray control and compaction monitoring through a digital platform, forming a complete quality control closed loop.

[0092] In a preferred embodiment, in the earth backfill construction method, the operation process of the atomizing spray system includes the following control method: obtaining meteorological data before construction, and automatically delaying the moisture content adjustment operation when the forecast wind force is greater than level 3; when implementing spraying, monitoring the wind speed of the working surface in real time, and immediately suspending spraying when the instantaneous wind speed is greater than 3m / s; adopting a zoned and segmented spraying strategy, dividing the area to be treated into 5m×5m grid units, and after each unit is sprayed, let it stand for 2 minutes before proceeding to the adjacent unit operation; within 30 minutes after spraying, conduct a secondary moisture content sampling test on the treated area, with a sampling ratio of 10%, and start compensatory spraying when the moisture content deviation is greater than ±1.5%.

[0093] The specific implementation process of the atomizing spray system operation method of the present invention is as follows:

[0094] During the construction preparation phase, the system automatically accesses real-time data from the Meteorological Bureau. If the forecast indicates wind speeds will reach level 4 within the next three hours, the central controller immediately issues a command to delay the sprinkler operation and displays a warning message on the construction interface. Ultrasonic anemometers are also installed on-site to monitor wind speed changes on the work surface in real time.

[0095] When wind speeds drop below 2.5 m / s, the system initiates the zoned spraying process. Operators divide the area to be treated into 5 m x 5 m square grids, and the system sprays every other grid cell. After spraying each grid cell, the system automatically pauses for 120 seconds to allow the water to fully penetrate before proceeding to the next cell. If wind speeds suddenly increase to 3.2 m / s during the spraying process, the system immediately shuts off the water supply and retracts the spray arms.

[0096] Within 30 minutes of completing the overall spraying process, quality inspectors randomly sample 10% of the grid cells for re-inspection. A rapid moisture content meter is used to measure the center and four corners of each sampled cell. If a cell's moisture content deviates by more than 1.8%, the system automatically retrieves the coordinates of that cell and controls the spraying equipment for precise compensation spraying.

[0097] Compared with the closest prior art, the present invention has the following significant advantages:

[0098] Traditional spraying operations rely solely on manual observation of wind conditions, often resulting in continued operation even in strong winds, leading to uneven spraying. This invention, through access to meteorological data and real-time wind speed monitoring, enables intelligent prediction and timely response to environmental risks.

[0099] The existing technology uses a continuous spraying method, which is easily affected by the cumulative effect of wind when operating over a large area. The zoning and segmentation strategy of the present invention, combined with the static interval, effectively reduces wind interference and ensures that each unit can be sprayed evenly.

[0100] Conventional methods rely on manual sampling and testing, often missing areas with substandard moisture content. The systematized review mechanism and precise positioning compensation of the present invention ensure uniformity and reliability of overall moisture content control.

[0101] In the existing technology, the various control links are separated from each other. The present invention realizes the full automation connection of meteorological monitoring, spraying operation and quality review through the intelligent control system, which greatly improves the construction efficiency and quality stability.

[0102] In a preferred embodiment, in the earth backfill construction method, the proportion of the pre-dried improved soil added is dynamically adjusted according to the original soil plasticity index Ip: when the original soil plasticity index Ip≤7%, the addition ratio is 10-12%; when 7%<Ip≤17%, the addition ratio is 15-18%; when Ip>17%, the addition ratio is 18-20%, and the mixing time after addition is extended to 1.5 times that of conventional soil.

[0103] Before backfilling, testers first conducted a plasticity index test on the undisturbed soil on site. Using a combined liquid-to-plastic limit tester, parallel tests were conducted on soil samples from three different locations. The measured plasticity indices were 6.3%, 14.7%, and 19.2%, respectively. The average value was ultimately used as the representative plasticity index for that batch of soil samples.

[0104] According to the test results, when the plasticity index of the soil sample is 6.3%, the system automatically selects a 10.5% improved soil mixing ratio; when the plasticity index is 14.7%, a 16% mixing ratio is used; for soil samples with a plasticity index of 19.2%, a 19% mixing ratio is used and the mixing time is extended to 1.5 times the normal time.

[0105] The mixing process is performed using an automatic batching and mixing machine. The machine accurately weighs the original soil and pre-dried, improved soil according to the input mixing ratio parameters. During the mixing process, the system automatically adjusts the mixing process for soil samples that require extended mixing time to ensure thorough mixing. After mixing is complete, samples are immediately taken to test the moisture content of the mixed soil to confirm that it has reached the optimal range of 98% to 102%.

[0106] Compared with the closest prior art, the present invention has the following outstanding advantages:

[0107] Traditional methods use a fixed 10-20% incorporation ratio for all soil types, which fails to specifically address the moisture content adjustment needs of different soil types. The present invention achieves precise matching of the incorporation ratio through plasticity index classification, significantly improving the moisture content adjustment effect.

[0108] The existing technology uses a uniform mixing time, which often results in uneven mixing for clay soil. The present invention dynamically adjusts the mixing time according to the soil characteristics, ensuring that the improved soil and the original soil are fully integrated and avoiding the problem of uneven local moisture content.

[0109] In conventional construction, the mixing ratio is mostly determined by empirical estimation and lacks scientific basis. The present invention establishes a quantitative standard through plasticity index testing, making the mixing process more standardized and reliable, and ensuring the consistency of construction quality.

[0110] In a preferred embodiment, in the earthwork backfill construction method, the flow control parameters of the atomizing spray system are dynamically adjusted according to the soil type: for sandy soil with a particle size greater than 0.075 mm and a particle content greater than 85%, 3-5 L / m 2 ·min high flow rate spraying, the standard value of the static time after spraying is 5min; for silt, 0.075mm≥particle size>0.005mm particle content≥50%, use 2-3L / m 2 ·min medium flow spray, the standard value of the static time after spraying is 10-15min; for clay, particle size ≤ 0.005mm particle content ≥ 30%, use 1-2L / m 2 For low-flow spraying of 100-200ml, the benchmark value of the standing time after spraying is 20-30min.

[0111] The specific implementation process of the soil adaptive spray control method of the present invention is as follows:

[0112] Before construction, the soil quality was first assessed on-site. Testers took representative soil samples for particle analysis, using sieving to determine the particle size distribution. If a sample in one area contained 88% particles larger than 0.075 mm, it was classified as sandy soil. Another area, with 55% particles between 0.075 and 0.005 mm, was classified as silt. And yet another area, with 35% particles smaller than 0.005 mm, was classified as clay.

[0113] The system automatically matches the spray parameters based on the soil quality determination results. For sandy soil areas, 4.2L / m 2 min spray flow rate, and let it stand for 4 minutes after spraying. For silt areas, use 2.5L / m 2 min flow rate, let it stand for 12 minutes; for clay areas, use 1.8L / m 2 min flow rate and let it stand for 25 minutes. During the spraying process, the operator will observe the water penetration in real time and make fine adjustments when necessary.

[0114] The spraying system uses an intelligent control system that automatically switches spray parameters for different soil types based on GPS positioning. When the roller enters a clay zone from a sandy soil zone, the system automatically reduces the spray flow rate and extends the subsequent rest time to ensure optimal wetting for all soil types.

[0115] Compared with the closest prior art, the present invention has the following significant advantages:

[0116] Conventional spraying uses a uniform rate of 3L / m for all soil types. 2The min flow rate and 10-minute rest time result in rapid water infiltration in sandy areas and surface water retention in clay areas. This invention solves the problem of uneven moisture content caused by differences in permeability characteristics by identifying soil properties and matching differentiated parameters.

[0117] In the existing technology, spray parameter adjustment relies on manual judgment, which is subjective and hysteretic. The automatic identification and switching system of the present invention realizes precise and real-time control of spray parameters, greatly improving construction efficiency and quality stability.

[0118] Conventional methods lack scientific control of the resting time, which often results in premature compaction of sand or clay. The present invention sets differentiated resting times based on soil properties, ensuring optimal distribution of water in various soil types.

[0119] In a preferred embodiment, in the earth backfill construction method, the compaction number is dynamically adjusted according to the real-time moisture content detection result, specifically satisfying the following relationship: N=N0+k·|w-wopt|, wherein: N is the actual compaction number; N0 is the benchmark compaction number, which is 3-5 times; k is the soil correction coefficient; w is the measured moisture content; wopt is the optimal moisture content; when |w-wopt| is greater than the set moisture content deviation dynamic threshold, the moisture content is first adjusted to 95%-105% of the optimal moisture content before compaction.

[0120] The specific implementation process of the dynamic compaction control method of the present invention is as follows:

[0121] During backfilling operations, the system collects real-time moisture content data for each area. If a certain area's moisture content is detected to be 96% of the optimal value, it will be compacted four times according to the baseline number of passes. If another area's moisture content reaches 102% of the optimal value, the system will automatically add one additional pass. If another area's moisture content is only 89% of the optimal value, the system will first activate spraying and then continue compaction after the moisture content reaches 98%.

[0122] Compaction is performed using an intelligent roller. The onboard control system displays the moisture content of the current area and the required number of compaction passes in real time. The operator performs the compaction according to the system's prompts, and the roller automatically records the number of passes completed. When the set number of passes is reached, the system prompts the operator to move to the next area.

[0123] For areas with large moisture content fluctuations, the system rechecks the moisture content after every two passes and dynamically adjusts the remaining passes based on the latest data. All compaction parameter adjustments for all areas are automatically saved to form a complete construction log.

[0124] Compared with the closest prior art, the present invention has the following outstanding advantages:

[0125] Traditional construction uses a fixed 4-6 compaction passes for all areas, which cannot be adjusted according to the actual moisture content. This invention achieves precise construction by dynamically linking moisture content and compaction passes, ensuring quality while avoiding energy waste caused by over-compaction.

[0126] In existing technologies, moisture content detection is disconnected from compaction operations. Often, compaction begins hours after detection, and the data is already inaccurate. The real-time linkage mechanism of this invention ensures that construction parameters are always based on the latest test data, greatly improving control accuracy.

[0127] Conventional methods cannot treat areas with abnormal moisture content and often require complete rework. The present invention's strategy of first adjusting and then compacting can target problem areas, significantly improving construction efficiency and quality stability.

[0128] In a preferred embodiment, in the earth backfill construction method, the dynamic threshold of moisture content deviation is set according to the soil type, and the setting method is as follows: for sand, particle size > 0.075mm, particle content ≥ 85%, the dynamic threshold of moisture content deviation is set to ±7%; for silt, 0.075mm ≥ particle size > 0.005mm, particle content ≥ 50%, the dynamic threshold of moisture content deviation is set to ±5%; for clay, particle size ≤ 0.005mm, particle content ≥ 30%, the dynamic threshold of moisture content deviation is set to ±3%.

[0129] The specific implementation process of the soil-differentiated moisture content threshold control method of the present invention is as follows:

[0130] During the construction preparation phase, testers first conducted a detailed classification of on-site soil samples. Through particle analysis, they accurately determined the soil types in each area: sandy soil (87% of the particles were larger than 0.075mm), silt (53% of the particles were 0.075-0.005mm), and clay (32% of the particles were smaller than 0.005mm).

[0131] The system automatically sets differentiated moisture content control thresholds based on soil classification results. Sandy soils are allowed to fluctuate within a range of plus or minus 7% of the optimal value; silt soils are controlled within a range of plus or minus 5%; and clay soils are strictly required to remain within a range of plus or minus 3%. These threshold parameters are pre-programmed into the intelligent control system.

[0132] During the construction process, when the moisture content of a certain sandy soil area is found to be 93% of the optimal moisture content (within the allowable range of ±7%), the system determines it as qualified and directly proceeds to the next process; while when the moisture content of another clay area is 94% of the optimal moisture content (outside the range of ±3%), the system immediately issues an alarm and requires moisture content adjustment.

[0133] Compared with the closest prior art, the present invention has the following significant advantages:

[0134] Traditional construction uses a uniform ±5% moisture content control standard for all soil types, which cannot meet the actual needs of different soil types. This invention uses soil-specific threshold settings to avoid over-adjustment in sandy soils while ensuring precise control in clay areas.

[0135] In the prior art, the determination of moisture content compliance relies entirely on manual experience, which is prone to misjudgment. The automatic threshold comparison system of the present invention achieves objective and accurate determination, greatly improving the reliability of quality control.

[0136] Conventional methods lack consideration for the permeability characteristics of different soil types, often leading to over-treatment of sandy areas or under-treatment of clay areas. The differentiated threshold settings of this invention fully respect the physical properties of various soil types, making construction more scientific and reasonable.

[0137] In a preferred embodiment, in the earth backfill construction method, the following real-time monitoring and dynamic adjustment measures are implemented during the compaction process, and the monitoring and dynamic adjustment measures include: a) dynamic tracking of moisture content: after each compaction construction is completed, the working surface is scanned for moisture content twice in a grid form, with a grid spacing of ≤1.5m; b) local over-limit processing: when it is detected that the moisture content deviation |w-wopt| in a local area exceeds the dynamic threshold of the moisture content deviation, a graded processing is performed: if the over-limit area is <5%, the area is marked and the compaction is skipped, and it is processed separately after the overall standard is met; if the over-limit area is ≥5%, the construction is immediately suspended and regional moisture content adjustment is started.

[0138] The specific implementation process of the compaction process dynamic monitoring method of the present invention is as follows:

[0139] During each layer compaction operation, operators use a mobile moisture content measurement vehicle to comprehensively scan the compacted area using a 1.2m x 1.2m grid. Equipped with a multi-probe sensor system, the vehicle continuously collects moisture content data while in motion and transmits it in real time to a central control platform.

[0140] When the system detects moisture content exceeding the permitted threshold within a 5m x 5m area, it automatically calculates the area of ​​the exceeded area. If the exceeded area is 3.2 square meters (approximately 4% of the detected area), the system simply marks that area on the electronic map, allowing operations to continue in other areas. If the exceeded area reaches 8 square meters (approximately 10%), the system immediately issues a pause command and initiates a special processing procedure.

[0141] For small areas marked as exceeding the standard, operators use small-scale compaction equipment to carry out targeted additional compaction after the overall compaction is completed. For larger areas exceeding the standard, a dedicated team adjusts the moisture content and then recompacts. All processing steps are systematically recorded, forming a complete quality traceability chain.

[0142] Compared with the closest prior art, the present invention has the following outstanding advantages:

[0143] Traditional methods use sampling inspection, which often misses local areas that exceed the standard. The full grid scanning of the present invention ensures the comprehensive discovery of quality problems and increases the inspection coverage rate to 100%.

[0144] Existing technologies halt construction work in all areas exceeding standards, severely impacting efficiency. The present invention's tiered treatment strategy achieves precise control, focusing on "intensive treatment for major problems and minor treatment for minor problems," improving construction efficiency by over 40%.

[0145] Conventional methods lack a systematic problem tracking mechanism. The electronic marking and recording system of this invention ensures closed-loop processing of each quality issue, significantly improving the reliability of construction quality.

[0146] In a preferred embodiment, in the earth backfill construction method, the soil correction coefficient k is determined by the following method:

[0147] Step (1) Indoor model test

[0148] Based on actual engineering soil samples, test groups were prepared with gravel contents of 0%, 10%, 20%, and 30%. Each group of soil samples was set at seven gradient moisture contents within the range of ±5% of the optimal moisture content. Compaction was performed using a standard compactor, and a three-dimensional relationship database was established between the moisture content deviation |w - wopt|, the number of compaction passes N, and the compaction degree K.

[0149] Step (2) On-site calibration test

[0150] Select typical areas on the working surface and conduct pressure tests based on field soil samples with gravel contents of 0%, 10%, 20%, and 30%; collect compaction energy and settlement data in real time;

[0151] Step (3) Dynamic k value calculation

[0152] k=α·(Ip / 17)+β·(G / 30)+γ

[0153] Where: Ip is the plasticity index (%), G is the gravel content (%), α, β, and γ are coefficients fitted by the least squares method, where α∈[0.8,1.2], β∈[-0.3,-0.1], and γ∈[0.2,0.5];

[0154] Step (4) Intelligent update mechanism

[0155] Every 1000m completed 2 After construction, new data is automatically collected to optimize the coefficients α, β, and γ.

[0156] The specific implementation process of the soil correction coefficient determination method of the present invention is as follows:

[0157] During the project's early preparation phase, test personnel collected representative soil samples from different areas on site and prepared a series of test groups in the laboratory with gravel contents of 0%, 10%, 20%, and 30%. Within each group, seven samples with varying moisture contents were prepared, with a 5% range above and below the optimal moisture content. Each sample was compacted using a standard compactor, and the number of passes required to achieve the desired compaction level was recorded to establish a comprehensive test database.

[0158] During on-site construction, pressure tests were conducted on typical areas of the work surface. Intelligent rollers were used for rolling, and sensors installed on the rollers collected real-time data on compaction energy and soil settlement. Field data was compared and analyzed with laboratory data, and the coefficients in the calculation formula were determined using least squares fitting.

[0159] After every 1,000 square meters of construction, the system automatically collects new construction data and optimizes the coefficients. If significant changes in gravel content are detected in a particular area, on-site calibration tests are promptly performed to ensure the calculation model remains relevant to current soil conditions.

[0160] Compared with the closest prior art, the present invention has the following significant advantages:

[0161] Traditional methods rely on experience to select a fixed k value, which cannot accurately reflect the differences in compaction characteristics of different soil types. Through systematic laboratory and field tests, this paper establishes a scientific and reliable k value calculation method, making the determination of compaction passes more accurate.

[0162] The existing technology ignores the influence of gravel content and has poor control effect on the compaction quality of gravel-containing soil. The present invention specifically considers the gravel content factor and establishes a dynamic update mechanism to ensure that the calculation results always conform to the actual engineering situation.

[0163] Conventional methods lack a continuous optimization mechanism and are unable to adapt to changes in soil conditions during construction. The regular data collection and coefficient update functions of this invention ensure the continued accuracy of the calculation model and significantly improve the stability of construction quality.

[0164] In a preferred embodiment, in the earth backfill construction method, the gravel content G is determined by taking into account the gravel particle size distribution, and specifically the k value is calculated by correcting the following method:

[0165] Step (1) Particle size classification detection

[0166] The soil samples were analyzed on site and divided into fine gravel group and coarse gravel group according to particle size. The particle size of the fine gravel group is 5-20mm, and the particle size of the coarse gravel group is 20-40mm.

[0167] Calculate the effective gravel content G of the on-site soil sample e =0.7G1+0.3G2, G1 is the gravel content of the fine gravel group, G2 is the gravel content of the coarse gravel group;

[0168] Step (2) Double correction of k value

[0169] In the calculation formula of the k value, the gravel content G is replaced by the effective gravel content G e ; Add particle size correction term δ, which takes effect when G2 / G1>1, δ=0.1×(G2 / G1);

[0170] The calculation formula of the corrected k value is k=α·(Ip / 17)+β·(G e / 30)+γ+δ.

[0171] The specific implementation process of the gravel content accurate assessment method of the present invention is as follows:

[0172] At the construction site, testers used digital image analysis equipment to conduct real-time testing on sampled backfill soil. The equipment automatically identified gravel particles in the soil samples and accurately classified them into two groups based on particle size: fine gravel (5-20 mm) and coarse gravel (20-40 mm). The system calculated that the fine gravel content in a particular area was 14% and the coarse gravel content was 6%. The effective gravel content was calculated as 0.7 times 14 plus 0.3 times 6, resulting in 11.6%.

[0173] If the ratio of coarse gravel to fine gravel in one area is 0.8, the particle size correction factor is disabled. However, if the ratio in another area reaches 1.5, the system automatically adds a correction factor of 0.1 times 1.5 (a total of 0.15) to the k-value calculation. All calculations are performed automatically by the intelligent system, and the results are displayed instantly on the control terminal.

[0174] After each construction section is completed, quality inspectors use a laser particle size analyzer to verify the calculated results. If the calculated results in a certain area deviate by more than 8% from the measured data, the system automatically prompts a manual re-inspection and adjusts the calculation formula parameters based on the re-inspection results.

[0175] Compared with the closest prior art, the present invention has the following outstanding advantages:

[0176] Traditional methods only count the total gravel content and cannot distinguish the effects of different particle sizes. The present invention uses particle size classification and weighted calculation to more accurately reflect the differentiated effects of coarse and fine gravel on compaction characteristics.

[0177] Existing techniques completely ignore the "false compaction" problem caused by a high proportion of coarse gravel. The particle size correction term added by the present invention effectively compensates for the measurement error caused by coarse particles, making the k value calculation more accurate and reliable.

[0178] Conventional methods lack an effective verification mechanism. The review and verification system of the present invention ensures the accuracy of the calculation results and forms a complete quality control closed loop.

[0179] In a preferred embodiment, in the earth backfill construction method, the method for controlling the standing time comprises the following steps:

[0180] Step (1) Environmental monitoring stage

[0181] Real-time monitoring of the following parameters: surface soil temperature, measuring depth 0-5cm; ambient wind speed, 1m above the ground;

[0182] Step (2) Dynamic Adjustment Stage

[0183] When the surface soil temperature is greater than 35°C and the wind speed is greater than 2m / s, the standing time is shortened by 30% based on the standing time benchmark value; when the surface soil temperature is less than 15°C and the relative humidity is greater than 75%, the standing time is extended by 40% based on the standing time benchmark value.

[0184] The specific implementation process of the environment-adaptive static control method of the present invention is as follows:

[0185] After the spraying operation was completed, operators immediately deployed a temperature and humidity monitoring network on the work surface. Insertable temperature sensors measured soil temperatures at a depth of 0-5 cm, while an anemometer was installed at a height of 1 meter above the ground. The monitoring system collected data every 5 minutes. If it detected a surface temperature of 36°C and a wind speed of 2.5 m / s, the system automatically shortened the initial 30-minute rest period to 21 minutes.

[0186] Under low ambient temperature conditions, when the surface soil temperature is monitored at 12°C and the relative humidity is 80%, the system extends the rest period to 42 minutes. It also automatically lays down porous thermally conductive material to promote even moisture distribution within the soil. During the rest period, the system continuously monitors changes in environmental parameters and makes dynamic adjustments as necessary.

[0187] After the rest period, operators use a dual-depth moisture meter to simultaneously measure the moisture content at 5cm and 20cm below the surface. If the difference between the two is less than 1.3%, the product is considered qualified and allowed to proceed to the next process. If the difference exceeds the standard, the rest period is appropriately extended and a moisturizing film is applied.

[0188] Compared with the closest prior art, the present invention has the following significant advantages:

[0189] Traditional construction uses a fixed resting time, which cannot adapt to changing environmental conditions. The present invention ensures the best resting effect in various climate conditions through real-time environmental monitoring and dynamic adjustment.

[0190] The existing technology lacks a scientific standard for determining readiness. The dual-depth moisture content comparison test of the present invention effectively avoids problems such as surface drying or internal water accumulation.

[0191] Conventional methods often fail to meet the requirements in extreme climates. The intelligent control system of the present invention, combined with physical protection measures, enables stable construction in all climate conditions.

[0192] Example 1

[0193] For example, a highway embankment backfill project involved a 200m long and 30m wide backfill area with a design requirement of 95% or higher compaction. The eastern section consisted of 55% silt with particles 0.075–0.005mm in diameter and a plasticity index (IP) of 15%. The western section consisted of 35% gravelly clay with particles ≤0.005mm in diameter, and a gravel content of 10% fine gravel (G1) and 5% coarse gravel (G2). Environmental conditions on the construction day included a temperature of 12°C, a relative humidity of 80%, and a wind speed of 1.8m / s.

[0194] The earthwork backfill construction method of the present invention includes the following specific implementation steps:

[0195] 1. Layered backfill and soil identification

[0196] The backfill area was divided into four layers, each 40 cm thick. On-site particle analysis determined that the eastern section was silt and the western section was clay with a gravel content of G = 15%.

[0197] 2. Dynamic control of moisture content

[0198] Treatment of silt in the eastern section: The initial moisture content was 8%, which was lower than the optimal moisture content w opt = 90% of 16%. Start the atomizing spray system: flow rate 2.5L / m 2 ·min, divided into 5m×5m grid operations, and left to stand for 12 minutes after spraying. The second test showed that the moisture content was 16.2%, which is between 95% and 105% w opt scope.

[0199] Treatment of gravel clay in the western section: the moisture content is 22%, which is higher than w opt =110% of 18%. According to the plasticity index Ip = 15%, 16% pre-dried improved soil moisture content is 6%, and the mixing time is extended to 1.5 times the normal. The moisture content of the mixed soil is reduced to 17.3%, which meets the requirements of 95%–105% w opt .

[0200] 3. Compaction and real-time monitoring

[0201] Dynamic adjustment of compaction passes: calculated k value is the effective gravel content G e =0.7×10%+0.3×5%=8.5%; particle size ratio G2 / G1=0.5<1, δ correction is not enabled; k=1.0×(15 / 17)-0.2×(8.5 / 30)+0.4=0.88, take α=1.0, β=-0.2, γ=0.4.

[0202] Eastern section silt soil |ww opt |=0.2%, <threshold ±5%, number of compaction passes N=4+0.88×0.2≈4 times.

[0203] Western clay |ww opt |=0.7%, <threshold±3%, N=4+0.88×0.7≈5 times.

[0204] Intelligent compaction monitoring: After each compaction pass, the moisture content is scanned with a 1.5m grid. opt | = 3.5%, area 4m 2 <5%, mark and postpone treatment, and re-pressurize separately after overall standards are met.

[0205] 4. Environmental Adaptive Static

[0206] After spraying, the surface soil temperature was monitored at 12°C and the humidity was 80%. The standing time was extended by 40%, with a clay benchmark of 30 minutes and an actual time of 42 minutes. At the end of the standing time, the difference in moisture content between the surface and deep layers was 0.8%, which was <1.5%, indicating compliance.

[0207] This embodiment has a 98% pass rate for compaction, uniform moisture distribution, a gradient difference of ≤1.5%, and no rework. This is achieved primarily through soil differentiation parameters (flow rate, standing time) to avoid silt waterlogging or clay runoff; k-value gravel content graded correction to improve the accuracy of gravel soil compaction prediction; environmental adaptive standing to overcome the problem of slow water penetration at low temperatures and high humidity; and local over-limit graded treatment to reduce overall downtime, thereby achieving the above-mentioned effects.

[0208] Comparative Example 1

[0209] The same engineering scenario and the same embankment backfill area as in Example 1 have the same soil quality and environmental conditions.

[0210] The specific implementation steps of the comparative method are as follows:

[0211] 1. Layered backfill

[0212] The layer thickness is 40cm, but it is not divided according to soil type.

[0213] 2. Moisture content control

[0214] Eastern section silt: manual sampling, drying and testing took about 4 hours, and the measured moisture content was 8%. The uniform rate was 3L / m 2 Spraying at a minimum flow rate, regardless of soil type, with continuous spraying without rest intervals. A secondary inspection revealed surface water content of 19%, while the deeper layers remained dry.

[0215] Western gravel clay: 18% modified soil was added, with no adjustment based on IP, and no extended mixing time. The mixed soil had a moisture content of 17%, but the gravel distribution was uneven.

[0216] 3. Compaction operation

[0217] The entire area was compacted six times, ignoring differences in moisture content. During single-point sampling, the eastern section showed overpressure due to water accumulation, resulting in spring soil, while the western section showed partial underpressure due to uneven mixing.

[0218] 4. Quality monitoring

[0219] Only 5 spots were randomly inspected, and 2 loose areas in the western section were missed, with an area of ​​8m 2 . After completion, the settlement test found that it was unqualified and the work had to be redone and refilled.

[0220] Construction analysis showed that the unified spraying parameters of Example 1 resulted in water accumulation in the eastern section and runoff in the western section; the fixed mixing ratio prevented the complete integration of the improved soil in the clay area; the relationship between moisture content and compaction times was ignored, resulting in over-compaction in the eastern section and under-compaction in the western section; the lack of grid scanning led to missed local defects; the fixed standing time resulted in insufficient moisture migration in the western section, ultimately resulting in a compaction qualification rate of 82%, two reworks, and a construction delay of 15 days.

[0221] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications can be easily implemented by those skilled in the art. Therefore, the present invention is not limited to the specific details without departing from the general concept defined by the claims and their equivalents.

Claims

1. A backfill construction method, characterized in that: The following steps are involved: Layered backfill: Divide the area to be backfilled into at least two layers of backfill areas. The thickness of each layer of backfill area is 30-50cm. Use a vibratory roller to compact each layer of backfill soil 3-5 times. Dynamic control of moisture content: Before backfilling each layer, the moisture content of the backfill soil is tested; if the moisture content is lower than 90% of the optimal moisture content, the atomizing spray system is used for uniform spraying and adjusted to 95%-105% of the optimal moisture content. The flow control range of the atomizing spray system is 2-5L / m 2 min; if the moisture content is higher than 110% of the optimum moisture content, the soil is spread and aired, or pre-dried improved soil is added, with the improved soil having a moisture content of ≤8% and a mixing ratio of 10-20%, so that the mixed soil moisture content reaches 95%-105% of the optimum moisture content; the optimum moisture content is determined by a modified Protz compaction test with a hammer weight of 4.5kg and a drop distance of 457mm; Intelligent compaction monitoring: Real-time monitoring of the compaction degree of each layer of backfill soil. If the compaction degree does not meet the design requirements, the area will be automatically marked and the re-compaction instruction will be triggered.

2. The earth backfill construction method according to claim 1, characterized in that: The operation process of the atomizing spray system includes the following control methods: Obtain meteorological data before construction. When the wind speed forecast is greater than level 3, the moisture content adjustment operation will be automatically delayed. When spraying, monitor the wind speed on the working surface in real time and stop spraying immediately when the instantaneous wind speed is greater than 3m / s; A zoned and segmented spraying strategy was adopted, dividing the area to be treated into 5m×5m grid units. After spraying each unit, it was left to stand for 2 minutes before proceeding to the adjacent unit. Within 30 minutes after spraying, conduct a secondary moisture content sampling test on the treated area with a sampling ratio of 10%. When the moisture content deviation is greater than ±1.5%, start compensatory spraying.

3. The earthwork backfill construction method according to claim 1, characterized in that: The proportion of pre-dried improved soil added is dynamically adjusted according to the original soil plasticity index Ip: When the original soil plasticity index Ip≤7%, the incorporation ratio is 10-12%; when 7%<Ip≤17%, the incorporation ratio is 15-18%; when Ip>17%, the incorporation ratio is 18-20%, and the mixing time after incorporation is extended to 1.5 times that of conventional soil.

4. The earth backfill construction method according to claim 3, characterized in that: The flow control parameters of the atomizing spray system are dynamically adjusted according to the soil type: For sandy soil, particle size> 0.075mm particle content ≥ 85%, use 3-5L / m 2 ·min high flow rate spraying, the standard value of the static time after spraying is 5min; for silt, 0.075mm≥particle size>0.005mm particle content≥50%, use 2-3L / m 2 ·min medium flow spray, the standard value of the static time after spraying is 10-15min; for clay, particle size ≤ 0.005mm particle content ≥ 30%, use 1-2L / m 2 For low-flow spraying of 100-200ml, the benchmark value of the standing time after spraying is 20-30min.

5. The earth backfill construction method according to claim 1, characterized in that: The number of compaction passes is dynamically adjusted according to the real-time moisture content detection result, specifically satisfying the following relationship: N=N0+k·|w-wopt|, Where: N is the actual number of compaction passes; N0 is the benchmark number of compaction passes, which is 3-5 times; k is the soil correction coefficient; w is the measured moisture content; wopt is the optimal moisture content; when |w-wopt| is greater than the set dynamic threshold of moisture content deviation, the moisture content is adjusted to 95%-105% of the optimal moisture content before compaction.

6. The earth backfill construction method according to claim 5, characterized in that: The dynamic threshold of moisture content deviation is set according to the soil type. The setting method is as follows: For sandy soil, particle size > 0.075 mm, particle content ≥ 85%, and the dynamic threshold of moisture content deviation is set to ± 7%; For silt, 0.075 mm ≥ particle size > 0.005 mm, particle content ≥ 50%, and the dynamic threshold of moisture content deviation is set to ±5%; For clay, the particle size is ≤ 0.005 mm, the particle content is ≥ 30%, and the dynamic threshold of moisture content deviation is set to ± 3%.

7. The earth backfill construction method according to claim 5, characterized in that: The following real-time monitoring and dynamic adjustment measures are implemented during the compaction process. The monitoring and dynamic adjustment measures include: a) Dynamic tracking of moisture content: After each compaction operation, the working surface is scanned for moisture content twice in a grid format, with a grid spacing of ≤1.5m; b) Local over-limit processing: When it is detected that the moisture content deviation in a local area |w-wopt| exceeds the dynamic threshold of the moisture content deviation, a hierarchical processing is performed: If the area exceeding the limit is less than 5%, mark the area and skip further compaction until the entire area meets the standard; If the excess area is ≥5%, construction will be suspended immediately and regional moisture content adjustment will be initiated.

8. The earth backfill construction method according to claim 5, characterized in that: The soil correction coefficient k is determined by the following method: Step (1) Indoor model test Based on actual engineering soil samples, test groups were prepared with gravel contents of 0%, 10%, 20%, and 30%. Each group of soil samples was set at seven gradient moisture contents within the range of ±5% of the optimal moisture content. Compaction was performed using a standard compactor, and a three-dimensional relationship database was established between the moisture content deviation |w - wopt|, the number of compaction passes N, and the compaction degree K. Step (2) On-site calibration test Select typical areas on the working surface and conduct pressure tests based on field soil samples with gravel contents of 0%, 10%, 20%, and 30%; collect compaction energy and settlement data in real time; Step (3) Dynamic k value calculation k=α·(Ip / 17)+β·(G / 30)+γ Where: Ip is the plasticity index (%), G is the gravel content (%), α, β, and γ are coefficients fitted by the least squares method, where α∈[0.8,1.2], β∈[-0.3,-0.1], and γ∈[0.2,0.5]; Step (4) Intelligent update mechanism Every 1000m completed 2 After construction, new data is automatically collected to optimize the coefficients α, β, and γ.

9. The earth backfill construction method according to claim 8, characterized in that: The determination of the gravel content G takes into account the gravel particle size distribution, and specifically the k value is calculated by correcting the following method: Step (1) Particle size classification detection The soil samples were analyzed on site and divided into fine gravel group and coarse gravel group according to particle size. The particle size of the fine gravel group is 5-20mm, and the particle size of the coarse gravel group is 20-40mm. Calculate the effective gravel content G of the on-site soil sample e =0.7G1+0.3G2, G1 is the gravel content of the fine gravel group, G2 is the gravel content of the coarse gravel group; Step (2) Double correction of k value In the calculation formula of the k value, the gravel content G is replaced by the effective gravel content G e ; Add particle size correction term δ, which takes effect when G2 / G1>1, δ=0.1×(G2 / G1); The calculation formula of the corrected k value is k=α·(Ip / 17)+β·(G e / 30)+γ+δ.

10. The earth backfill construction method according to claim 4, characterized in that: The control method of the standing time comprises the following steps: Step (1) Environmental monitoring stage Real-time monitoring of the following parameters: surface soil temperature, measuring depth 0-5cm; ambient wind speed, 1m above the ground; Step (2) Dynamic Adjustment Stage When the surface soil temperature is greater than 35°C and the wind speed is greater than 2m / s, the standing time is shortened by 30% based on the standing time benchmark value; when the surface soil temperature is less than 15°C and the relative humidity is greater than 75%, the standing time is extended by 40% based on the standing time benchmark value.