Construction method for mixing and compacting lime soil

Abstract

The invention discloses a construction method for mixing and compacting lime soil, and belongs to the technical field of civil engineering. The construction method comprises the five steps of three-dimensional grid division, intelligent paving, double-stage mixing, intelligent compaction and quality tracing. A construction area is divided into standard operation units, and RFID positioning piles are arranged; a spreading vehicle with a GNSS (Global Navigation Satellite System), a laser ranging system and a pneumatic conveying system is adopted for intelligent spreading; through the combination of coarse mixing and fine mixing, the mixing depth is dynamically adjusted; compacting equipment is adopted to carry out compacting operation on the basis of the real-time detected compacting parameters; and storing the data by using a block chain technology and generating a quality identification code. According to the method, traditional construction defects are overcome, the single-day treatment capacity reaches 4500 m, the efficiency is improved by 275%, the lime dosage deviation is reduced to + / -0.8%, lime is saved by 23%, and the method is suitable for treating the foundation of the industrial factory building with the ultra-large area.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of civil engineering foundation treatment, and particularly relates to a construction method for lime-soil mixing and compaction. BACKGROUND

[0002] In the field of civil engineering foundation treatment, lime-soil mixing and compaction construction is a commonly used process, but the traditional construction method has many technical defects and cannot meet the requirements of large-area and high-quality foundation treatment.

[0003] Low control accuracy of lime dosage: manual lime paving is prone to unevenness, resulting in a local lime dosage deviation of more than ±1.5%, affecting the strength and stability of lime-soil, and increasing the risk of foundation settlement in the later period.

[0004] Insufficient mixing depth accuracy: the control accuracy of single mixing depth is only ±50mm, which is prone to soil interlayer, damages the overall structure of the foundation, reduces the bearing capacity of the foundation, and cannot meet the requirements of loess-like soil properties.

[0005] Lagging in compaction quality monitoring: there is a lack of real-time monitoring means for compaction operation, and manual sampling detection is required, which is not only low in efficiency, but also has limitations in sampling, and cannot fully reflect the quality of 100% operation surface, especially in the construction of super-long operation surface (such as operation surface of more than 700m), it is difficult to maintain the consistency of continuous construction quality.

[0006] Poor mechanical adaptability: the existing technology uses a road mixer to automatically adjust the depth, but the mechanical depth sensor is prone to errors due to the adhesion of lime-soil, and cannot adapt to the rapid fluctuation of loess-like soil water content of 3-5%, the construction efficiency cannot meet the requirements of large-scale buildings of 160,000 square meters or more, and the maintenance cost of expensive automatic depth adjustment mixing machine is high, increasing the construction cost. SUMMARY

[0007] The application aims to provide a construction method for lime-soil mixing and compaction, which solves the problems of large lime dosage deviation, insufficient mixing depth accuracy, difficult compaction quality monitoring, poor consistency of operation surface quality, and weak mechanical adaptability in traditional construction.

[0008] The technical solutions adopted by the application are as follows:

[0009] A construction method for lime-soil mixing and compaction, comprising the following steps:

[0010] S1, grid division: dividing the construction area into multiple standard operation units, and installing an RFID chip on the positioning pile of each operation unit, the RFID chip storing geological parameters of the corresponding operation unit;

[0011] S2. Spreading: Lime is spread using a self-propelled lime spreader. The lime spreader is equipped with a GNSS positioning system and a laser rangefinder. It automatically adjusts the spreading amount according to the preset lime dosage curve and the geological parameters of the work unit, and performs secondary leveling through a grid scraper device.

[0012] S3. Mixing: First, use a rotary tiller for coarse mixing, and then use a mixer for fine mixing based on real-time soil moisture content detection.

[0013] S4. Compaction: Compaction is carried out using compaction equipment based on real-time detected compaction parameters;

[0014] S5. Quality Traceability: Associate the construction data generated by each work unit in steps S2 to S4 with the unique identification information of the RFID chip and store it in the blockchain system to generate a traceable quality identification code.

[0015] In some embodiments, the lime spreader is equipped with a pneumatic conveying system, and the spreading accuracy of the lime spreader meets the following requirements: lateral distribution variation coefficient ≤ 8%, longitudinal distribution deviation ≤ ±0.5 kg / m².

[0016] In some of these embodiments, in step S3:

[0017] The rotary tiller is equipped with a multispectral sensor for real-time detection of the uniformity of the mixture of ash and soil.

[0018] The mixing machine is equipped with a hydraulic depth adjustment device, which dynamically adjusts the mixing depth based on the real-time detected soil moisture content.

[0019] The dynamic adjustment of the mixing depth is achieved through the following formula:

[0020]

[0021] Where H is the actual mixing depth, H0 is the designed mixing depth, and W is the real-time soil moisture content.

[0022] In some embodiments, the mixer employs a double-blade structure, wherein the upper blades are arranged spirally and rotate at 120-150 rpm, and the lower blades have a wavy structure and rotate at 80-100 rpm.

[0023] In some of these embodiments, the compaction equipment includes a vibratory roller group equipped with an acceleration sensor, a compaction degree calculation module, and a laser smoothness measuring instrument;

[0024] The compaction calculation module generates a compaction energy distribution map based on the vibration acceleration detected by the acceleration sensor and dynamically adjusts the number of rolling passes. The laser smoothness measuring instrument scans and generates a 3D smoothness model to guide local compaction.

[0025] In some embodiments, the compaction equipment is further configured with a multi-parameter feedback system, which includes an automatic vibration frequency adjustment module and a closed-loop control system for travel speed.

[0026] In some embodiments, the compaction calculation module calculates the compaction degree in real time based on the following model. :

[0027]

[0028] Where a is the vibration acceleration, V is the speed of the road roller, and N is the number of compaction passes.

[0029] In some embodiments, the standard operating unit is 5m × 5m in size, and each standard operating unit is provided with 4 positioning stakes, with the RFID chip installed on the top of the positioning stakes.

[0030] In some of these embodiments, the quality identification code includes a timestamp and geological parameters.

[0031] Compared with the prior art, the present invention has at least one of the following advantages or beneficial effects:

[0032] Significantly improved construction efficiency: Through the application of intelligent equipment, automation and collaborative operation of all aspects of construction are realized, with a daily processing capacity of up to 4,500 m³, which is 275% higher than traditional construction methods. It can quickly complete the foundation treatment of ultra-large industrial plants and shorten the construction cycle.

[0033] Significantly enhanced quality stability: By adopting intelligent paving and two-stage mixing technology, the ash dosage deviation is reduced from the traditional ±1.5% to ±0.8%, and the mixing depth accuracy is controlled within ±10mm, avoiding the formation of soil interlayers; through intelligent compaction and real-time monitoring, the compaction degree is ensured to meet the standard and the flatness is ≤5mm. Real-time quality monitoring of the working surface greatly improves the quality stability of foundation treatment, and the characteristic value of foundation bearing capacity can reach 180kPa, meeting the requirements for use in industrial plants.

[0034] Effective savings in materials and costs: Precise lime dosage control and intelligent paving technology reduce lime waste by 23%; real-time quality monitoring and timely compaction reduce rework rate by 95%, reducing material, labor and time costs incurred due to rework; at the same time, there is no need to use expensive road mixing machines with automatic depth adjustment, reducing equipment purchase and maintenance costs, and significantly reducing overall construction costs.

[0035] Highly intelligent and traceable: It integrates advanced technologies such as GNSS positioning, multispectral sensing, and blockchain to achieve digital control and data traceability throughout the construction process. The quality identification code can quickly query the construction data of the work unit, which facilitates quality supervision and accountability. At the same time, the diverse functions of the human-machine interaction layer improve the level of intelligent construction management, reduce manual intervention, and reduce the labor intensity and human error of personnel. Attached Figure Description

[0036] Figure 1 This is a flowchart of the construction method for mixing and compacting lime-soil in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of three-dimensional mesh division in an embodiment of the present invention;

[0038] Figure 3 This is a flowchart of the compaction feedback control in an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0040] like Figure 1 As shown, this invention discloses a construction method for mixing and compacting lime-soil, characterized by comprising the following steps:

[0041] S1: 3D Grid Division: The construction area is divided into multiple 5m×5m standard work units. Each work unit is equipped with 4 positioning stakes (the 4 positioning stakes are distributed in a rectangle, and the distance between adjacent positioning stakes is 5m). An RFID chip is installed on the top of the positioning stake. The RFID chip stores the geological parameters of the corresponding work unit. These geological parameters include soil type (such as loess soil, sandy soil), design compaction degree (≥95%), design mixing depth (15-40cm), groundwater level depth, and soil organic matter content. The RFID chip reading distance is ≥3m to ensure that the construction equipment can obtain the geological parameters of the work unit in real time.

[0042] Figure 2 The work units are marked with different colors (yellow, blue, and red) to display parameters such as bearing requirements, soil type, and ash dosage for each unit, as well as the location of positioning piles and elevation control points, intuitively presenting the three-dimensional grid division and parameter distribution.

[0043] S2: Intelligent paving: The self-propelled lime spreader equipped with a Beidou + GPS dual-mode GNSS positioning system (positioning accuracy ≤1m), a laser rangefinder (measurement range 0-20cm, accuracy ±2mm) and a pneumatic conveying system performs the following operations: Based on the geological parameters of the work unit read from the RFID chip and the preset lime dosage curve; the spreading amount is automatically adjusted according to the preset lime dosage curve through the pneumatic conveying system of the lime spreader, controlling the lateral distribution variation coefficient ≤8% and the longitudinal distribution deviation ≤±0.5kg / m²; after paving, a grid scraper device is used for secondary leveling to ensure that the lime paving thickness error is ≤±5mm.

[0044] S3: Two-stage mixing: A two-stage process of coarse mixing and fine mixing is adopted to achieve uniform mixing of ash and soil and precise control of depth.

[0045] Coarse mixing stage: A rotary tiller equipped with a multispectral sensor (detection wavelength 400-700nm) is used to detect the RGB spectrum value of the ash soil in real time. When the spectral value deviation exceeds ±10% (i.e., the mixing degree < 90%), a supplementary mixing command is triggered to ensure that there are no soil clumps after coarse mixing.

[0046] Fine mixing stage: A special mixing machine equipped with a hydraulic depth adjustment device (response time ≤ 0.5s) is used. The mixing machine adopts a double-layer blade structure. Specifically, the upper blade is spirally arranged (rotation speed 120-150rpm, responsible for surface crushing), and the lower blade is wavy (rotation speed 80-100rpm, responsible for deep mixing). At the same time, based on the real-time detected soil moisture content (unit: mass percentage), the mixing depth is dynamically adjusted by the following formula (1) to ensure that the particle size of the lime-soil after fine mixing is ≤ 5cm.

[0047] Formula (1)

[0048] Where: H is the actual mixing depth (unit: cm), H0 is the designed mixing depth (unit: cm), W is the real-time soil moisture content (unit: %), and the formula is applicable to the range of W=15%−22% (covering the common moisture content range of loess-like soil).

[0049] S4: Intelligent Compaction: A roller group consisting of 3 or more Dynapac CC6200 double-drum vibratory rollers is configured. Each roller is equipped with an acceleration sensor, a compaction degree calculation module, and a laser roughness measuring instrument. The roller group is equipped with a multi-parameter feedback system, including an automatic vibration frequency adjustment module (adjustment range 20-40Hz) and a closed-loop control system for travel speed (speed control accuracy ±0.5km / h). When the calculated K≥95%, the compaction operation in that area is automatically stopped. The laser roughness measuring instrument scans in real time to generate a 3D roughness model of the work unit, plans a compaction path for areas with roughness > 5mm, and performs local compaction.

[0050] Specifically, the compaction calculation module calculates the compaction degree in real time using the following formula (2) and dynamically adjusts the number of compaction passes (3-8 passes):

[0051] Formula (2)

[0052] Where: K is the degree of compaction (unit: %), a is the vibration acceleration (unit: m / s²), V is the driving speed (unit: km / h), and N is the number of compaction passes;

[0053] like Figure 3 As shown, after the vibratory roller is started, data such as vibration acceleration, travel speed, and number of compaction passes are collected to calculate the compaction degree and determine whether the compaction degree meets the standard. If it does not meet the standard, the parameters are adjusted and the number of compaction passes is increased. At the same time, the smoothness is checked until the standard is met, and then an acceptance report is generated or the process of additional compaction is performed.

[0054] S5: Quality Traceability: The construction data (including ash dosage, mixing depth, compaction degree, flatness, equipment number, and operation time) of each work unit in steps S2-S4 are associated with the unique identification information of the corresponding RFID chip and uploaded to a blockchain system based on Hyperledger Fabric 2.4 via a 5G IoT gateway. The blockchain system includes four types of nodes: construction unit, supervision unit, owner, and quality inspection agency. It adopts the PBFT consensus mechanism (consensus latency < 2s, verification time 300ms / time), generates a block every 30s (block size 1MB), and generates a unique quality identification code for each work unit, including a timestamp, work unit coordinates (e.g., X=325.14m, Y=82.67m), and construction parameters, to achieve tamper-proof construction data and full life-cycle traceability.

[0055] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A construction method for mixing and compacting lime-soil, characterized in that, Includes the following steps: S1. Grid division: The construction area is divided into multiple standard work units, and an RFID chip is installed on the positioning stake of each work unit. The RFID chip stores the geological parameters of the corresponding work unit. S2. Spreading: Lime is spread using a self-propelled lime spreader. The lime spreader is equipped with a GNSS positioning system and a laser rangefinder. It automatically adjusts the spreading amount according to the preset lime dosage curve and the geological parameters of the work unit, and performs secondary leveling through a grid scraper device. S3. Mixing: First, use a rotary tiller for coarse mixing, and then use a mixer for fine mixing based on real-time soil moisture content detection. S4. Compaction: Compaction is carried out using compaction equipment based on real-time detected compaction parameters; S5. Quality Traceability: Associate the construction data generated by each work unit in steps S2 to S4 with the unique identification information of the RFID chip and store it in the blockchain system to generate a traceable quality identification code.

2. The construction method for mixing and compacting lime-soil as described in claim 1, characterized in that, The lime spreader is also equipped with a pneumatic conveying system.

3. The construction method for mixing and compacting lime-soil as described in claim 1, characterized in that, In step S3: The rotary tiller is equipped with a multispectral sensor for real-time detection of the uniformity of the mixture of ash and soil. The mixing machine is equipped with a hydraulic depth adjustment device, which dynamically adjusts the mixing depth based on the real-time detected soil moisture content. The dynamic adjustment of the mixing depth is achieved through the following formula: , Where H is the actual mixing depth, H0 is the designed mixing depth, and W is the real-time soil moisture content.

4. The construction method for mixing and compacting lime-soil as described in claim 1, characterized in that, The mixer adopts a double-layer blade structure, wherein the upper layer blades are arranged in a spiral and rotate at 120-150 rpm, and the lower layer blades have a wavy structure and rotate at 80-100 rpm.

5. The construction method for mixing and compacting lime-soil as described in claim 1, characterized in that, The compaction equipment includes a vibratory roller group, which is equipped with an acceleration sensor, a compaction degree calculation module, and a laser smoothness measuring instrument. The compaction calculation module generates a compaction energy distribution map based on the vibration acceleration detected by the acceleration sensor and dynamically adjusts the number of rolling passes. The laser smoothness measuring instrument scans and generates a 3D smoothness model to guide local compaction.

6. The construction method for mixing and compacting lime-soil as described in claim 5, characterized in that, The compaction equipment is also equipped with a multi-parameter feedback system, which includes an automatic vibration frequency adjustment module and a closed-loop control system for travel speed.

7. The construction method for mixing and compacting lime-soil as described in claim 6, characterized in that, The compaction degree calculation module calculates the compaction degree in real time based on the following model. : ， Where a is the vibration acceleration, V is the speed of the road roller, and N is the number of compaction passes.

8. The construction method for mixing and compacting lime-soil as described in claim 1, characterized in that, The standard operating unit is 5m×5m in size, and each standard operating unit is equipped with 4 positioning stakes, with the RFID chip installed on the top of the positioning stake.

9. The construction method for mixing and compacting lime-soil as described in claim 1, characterized in that, The quality identification code includes a timestamp and geological parameters.

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