Vibration-free foundation construction method for collapsible loess

Abstract

The invention discloses a vibration-free foundation construction method for collapsible loess. The construction method provided by the invention comprises the following steps: dividing a construction area into grids, taking the intersection points of the grids as compaction points, detecting the initial dry density of the compaction points, drawing a density distribution thermodynamic diagram according to the initial dry density, and setting the initial pressure of compaction treatment on each compaction point according to the density distribution thermodynamic diagram; according to the initial pressure, compaction treatment is carried out at the compaction point, and gradient pressurization is carried out in the compaction treatment process until the preset depth is reached; regulating the water content to 18-22% according to the water content of the loess in the construction area; and the compaction point and the soil body compactness around the compaction point and the vibration acceleration of buildings around the construction area are monitored in real time, and when the soil body compactness change rate is smaller than 1% and the vibration acceleration is smaller than 0.1 g in at least three continuous detection periods, foundation treatment reaches the standard.

Description

Technical Field

[0001] This invention relates to the field of foundation construction technology, and specifically to a vibration-free foundation construction method for collapsible loess. Background Technology

[0002] Northern my country is dominated by collapsible loess, which undergoes significant subsidence upon contact with water due to changes in its particle structure, severely impacting foundation stability. Current urban construction projects, such as the renovation of old urban areas and construction around schools and hospitals in densely populated areas, all require addressing this type of foundation. These areas are surrounded by residential buildings and environmentally sensitive sites, necessitating both ensuring foundation stability to prevent building settlement and cracking, and minimizing the impact on the surrounding environment. Related technologies are a key focus in the engineering construction field.

[0003] Construction problems are prominent in these scenarios: densely populated areas require a quiet and stable environment, and construction vibration and noise can interfere with residents' lives, school teaching and hospital treatment; old buildings are inherently fragile, and vibration can easily cause their walls to crack and their foundations to settle; in addition, the area is narrow, making it difficult for large machinery to operate, and collapsible loess is sensitive to water content, making it difficult to accurately control on site, which can easily lead to substandard foundation treatment quality.

[0004] Traditional technologies, such as dynamic compaction and immersed tube compaction, are commonly used in the industry to address this issue. These methods are suitable for open areas like suburban factories and newly constructed roads, improving loess density, reducing collapsibility, and ensuring foundation stability; they are the mainstream approaches. However, in densely populated areas, traditional methods have significant drawbacks: dynamic compaction's vibrations are transmitted to the surrounding area, easily causing building cracks and foundation settlement; both methods generate high-decibel noise, failing to meet environmental protection requirements; they require large machinery and ample space, making them difficult to operate in narrow areas; and they have strict requirements for soil moisture content, which is difficult to adjust precisely on-site, and deviations can lead to substandard foundation treatment and potential subsequent settlement, making them unsuitable for such scenarios. Summary of the Invention

[0005] In order to solve the problems of vibration and noise pollution and substandard foundation treatment caused by existing construction methods, the purpose of this invention is to provide a vibration-free foundation construction method for collapsible loess.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a vibration-free foundation construction method for collapsible loess, comprising the following steps: S1, the construction area is divided into a grid, and the intersection of the grid is the compaction point. The initial dry density of the compaction point is detected, and a density distribution heat map is drawn based on the initial dry density. The initial pressure of compaction treatment at each compaction point is set based on the density distribution heat map. S2, based on the initial pressure, perform rotary extrusion compaction at the compaction point, and apply gradient pressure during the rotary extrusion compaction process until the preset depth is reached; S3, adjust the moisture content to 18-22% based on the moisture content of the loess in the construction area; S4 monitors the soil compaction at the compaction point and its surroundings, as well as the vibration acceleration of buildings around the construction area in real time. If the soil compaction change rate is less than 1% and the vibration acceleration is less than 0.1g for at least three consecutive monitoring cycles, the foundation treatment meets the standards.

[0007] Furthermore, in S1, the initial dry density at the compaction point is detected, and a density distribution heatmap is plotted based on the initial dry density. Uncirculated soil samples were taken at depths of 0.5, 1.5, and 2.5 m at each compaction point for testing. Density distribution heat maps were plotted based on the test data, and a database corresponding to the initial dry density and the optimal compaction pressure was established.

[0008] Furthermore, the detection data includes initial dry density, natural moisture content, porosity, and collapsibility coefficient δs.

[0009] Furthermore, in S2, the rotary extrusion compaction process specifically includes: The soil should be penetrated at an initial velocity of 20-30 mm / s, with the pressure increased by 0.5-1.5 MPa for every 50 mm of penetration, not exceeding 80% of the soil's ultimate bearing capacity. When the pressure reaches the preset final pressure value or the penetration speed is less than 2 mm / min, maintain the pressure for 30 to 60 seconds and then release the pressure.

[0010] Furthermore, prior to the rotary extrusion compaction process, the following steps are also included: A guide hole is pre-formed at the compaction point, and the diameter of the guide hole is 10-15 mm smaller than the retractable probe used for rotary extrusion compaction. Cement slurry mist is sprayed into the guide hole to form a lubricating and insulating layer, with a water-cement ratio of 0.8 to 1.2.

[0011] Furthermore, in S3, the moisture content of the loess in the construction area is monitored in the following ways: The moisture content distribution of the soil after compaction is detected by humidity sensors arranged in a ring around the compaction point, and a moisture content contour map is drawn based on the moisture content. The moisture content contour map is updated every 3 minutes, and abnormal areas are automatically marked.

[0012] Furthermore, in S3, the adjustment of the moisture content to 18-22% specifically involves: Before adjusting the moisture content, if the similarity of the pressure-penetration curves of five consecutive compaction points in the same work area is greater than 90%, batch moisture content control can be initiated. If the moisture content is below 18%, replenish water at a rate of 5~10L / m²; use a pulsed spraying method. If the water content is higher than 22%, remove the pore water, and the pumping rate should not exceed 5L / min. Stop adjusting the moisture content after it has been detected to be stable between 18% and 22% for 10 minutes.

[0013] Furthermore, S4 monitors the soil compaction at and around the compaction point, as well as the vibration acceleration data of surrounding buildings, in real time, specifically as follows: A dynamic monitoring system was installed within a 1-meter radius around the compaction point. Based on the monitoring data, the soil density and vibration acceleration data of surrounding buildings are calculated in real time, and a three-dimensional compaction cloud map is generated through the control terminal to provide on-site technicians with the test results. When the density change rate is <1% and the vibration acceleration is <0.1g within three consecutive testing cycles, the foundation treatment is deemed to meet the standards; if it does not meet the standards, repeat steps S2-S4.

[0014] Furthermore, the dynamic monitoring group specifically includes: Vertical monitoring: A vibrating wire pore water pressure gauge with a range of 0-500 kPa is installed at the center of the compaction point; Horizontal monitoring: Miniature inclinometers are arranged radially at 0.5m intervals, with an accuracy of 0.01°; Environmental monitoring: Install three-phase accelerometers at the foundations of buildings around the construction area, with a sampling frequency of ≥50Hz.

[0015] Furthermore, S4 also includes: conducting static load tests in areas where the foundation treatment meets the standards, with the load being 1.2 times the preset value of the foundation bearing capacity; and supplementing grouting reinforcement in local areas with settlement > 5 mm.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This foundation construction method based on collapsible loess replaces the traditional vibration construction method with rotary compaction technology, effectively mitigating vibration and noise pollution during construction and avoiding interference with surrounding buildings and sensitive environments. It is particularly suitable for areas with high requirements for quietness, such as hospitals and schools. Simultaneously, by intelligently controlling soil moisture content and monitoring the compaction effect in real time, it ensures uniform and stable foundation treatment, significantly improving the foundation's bearing capacity and resistance to collapse, meeting high-standard engineering requirements. Furthermore, it employs an integrated automated control system and a real-time data feedback mechanism to achieve precise adjustment of construction parameters and full-process monitoring, greatly improving construction efficiency and quality control. It also optimizes the construction process, reduces mechanical energy consumption and manual intervention, and lowers overall construction costs while ensuring project quality, resulting in significant economic benefits. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic flowchart of the method for constructing a vibration-free foundation for collapsible loess according to the present invention. Detailed Implementation

[0019] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0020] In this invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0021] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0022] It should be understood that in various embodiments of the present invention, the order of the above-mentioned processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0023] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] The weights of the relevant components mentioned in the embodiments of this invention can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this invention is within the scope disclosed in the embodiments of this invention. Specifically, the mass described in the embodiments of this invention can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0025] Please see Figure 1 A vibration-free foundation construction method for collapsible loess includes the following steps: S1, the construction area is divided into a grid, and the intersection of the grid is the compaction point. The initial dry density of the compaction point is detected, and a density distribution heat map is drawn based on the initial dry density. The initial pressure of compaction treatment at each compaction point is set based on the density distribution heat map. S2, based on the initial pressure, compaction is performed at the compaction point, and gradient pressure is applied during the compaction process until the preset depth is reached; S3, adjust the moisture content to 18-22% based on the original soil moisture content in the construction area; S4 monitors the soil compaction at the compaction point and its surroundings, as well as the vibration acceleration of buildings around the construction area in real time. If the soil compaction change rate is less than 1% and the vibration acceleration is less than 0.1g for at least three consecutive monitoring cycles, the foundation treatment meets the standards.

[0026] Furthermore, in S1, the construction area is divided into a grid, the initial dry density at the grid intersections is detected, a density distribution heat map is plotted based on the initial dry density, and the initial pressure for compaction treatment at each compaction point is set based on the density distribution heat map, specifically: The construction area is divided into square grids of 2-3m, and the intersection of the grids is the compaction point; Uncirculated soil samples were taken at depths of 0.5, 1.5, and 2.5 m at each compaction point for testing. The test parameters included initial dry density, natural water content, void ratio, and collapsibility coefficient δs. A density distribution heat map was plotted based on the test data, and a database of the correspondence between initial dry density and optimal compaction pressure was established. Adjust the initial pressure parameters of the compaction equipment at each compaction point according to the density distribution heat map; Furthermore, in S2, based on the initial pressure, compaction is performed at the compaction point. During the compaction process, gradient pressure is applied until a preset depth is reached, specifically as follows: Position the rotary extrusion compaction equipment at the compaction point and unfold the support structure of the rotary extrusion compaction equipment; The retractable probe is driven by the hydraulic system of the rotary compaction equipment to penetrate the soil at an initial speed of 20~30mm / s. The pressure is increased by 0.5~1.5MPa for every 50mm of penetration, and the maximum pressure shall not exceed 80% of the ultimate bearing capacity of the soil. When the pressure gauge reading reaches the preset final pressure value or the probe penetration speed is less than 2 mm / min, maintain the pressure for 30 to 60 seconds and then release the pressure.

[0027] Before the rotary extrusion compaction process, the following steps are also included: A pilot hole is pre-formed at the compaction point using a twin-spiral drill bit. The diameter of the pilot hole is 10-15 mm smaller than that of the telescopic probe. Cement slurry mist is sprayed into the guide hole to form a lubricating and insulating layer, with a water-cement ratio of 0.8 to 1.2.

[0028] Before adjusting the moisture content, if the similarity of the pressure-penetration curves of five consecutive compaction points in the same work area is greater than 90%, batch moisture content control can be initiated. Adjacent compaction points should be sprayed intermittently, with an interval of no less than 1 hour between operations; After the compaction treatment is completed, the soil samples are tested. The test indicators include: soil dry density, natural water content, void ratio, and collapsibility coefficient δs, to evaluate the compaction effect.

[0029] Furthermore, in S3, the moisture content of the loess in the construction area is adjusted to 18-22%, specifically as follows: The moisture content distribution of the soil after compaction is detected by humidity sensors arranged in a ring around the compaction point, and a moisture content contour map is drawn based on the moisture content. The moisture content contour map is updated every 3 minutes, and abnormal areas are automatically marked.

[0030] If the moisture content is below 18%, start the rotary spray device to replenish water at a rate of 5~10L / m²; use pulsed spraying with a working cycle of 30s spraying and 60s intermittent spraying, and control the water droplet size to 100~200μm. If the water content is higher than 22%, start the vacuum suction device to remove the pore water; maintain the vacuum degree at 0.06~0.08MPa and the suction rate at no more than 5L / min; The humidity sensor stops adjusting the humidity level after detecting that the moisture content has been stable between 18% and 22% for 10 minutes. Furthermore, S4 monitors the soil compaction and surrounding soil density, as well as the vibration acceleration data of surrounding buildings, in real time. Based on the soil compaction and vibration acceleration data of surrounding buildings, it determines whether the foundation treatment meets the standards. Specifically, this includes the following steps: A dynamic monitoring system is installed within a 1m radius around the compaction point; the dynamic monitoring system specifically includes: Vertical monitoring: A vibrating wire pore water pressure gauge with a range of 0-500 kPa is installed at the center of the compaction point; Horizontal monitoring: Miniature inclinometers are arranged radially at 0.5m intervals, with an accuracy of 0.01°; Environmental monitoring: Install three-phase accelerometers at the foundations of buildings around the construction area, with a sampling frequency of ≥50Hz.

[0031] Based on the monitoring data, the soil density and vibration acceleration data of surrounding buildings are calculated in real time. A three-dimensional compaction cloud map is generated through the control terminal and provided to on-site technicians to judge the test results. The test cycle is 20 minutes.

[0032] When the density change rate is <1% and the vibration acceleration is <0.1g within three consecutive testing cycles, the foundation treatment is deemed to meet the standards; if it does not meet the standards, repeat steps S2-S4.

[0033] S4 also includes: Static load tests were conducted in areas where the foundation treatment met the standards, with the load being 1.2 times the preset value of the foundation bearing capacity; grouting reinforcement was added to local areas with settlement > 5 mm. Generate a digital construction log containing construction parameters and monitoring data for each location.

[0034] This foundation construction method based on collapsible loess replaces traditional vibration construction methods with rotary compaction technology, effectively mitigating vibration and noise pollution during construction and avoiding interference with surrounding buildings and sensitive environments. It is particularly suitable for areas with high quiet requirements, such as hospitals and schools. Intelligent control of soil moisture content and real-time monitoring of compaction effects ensure uniform and stable foundation treatment, significantly improving bearing capacity and resistance to collapse, meeting high engineering standards. The use of adjustable-size compaction equipment and modular design allows for flexible operation in narrow or restricted construction sites, solving the problem of traditional methods being difficult to implement in densely populated urban areas. An integrated automated control system and real-time data feedback mechanism enable precise adjustment of construction parameters and full-process monitoring, significantly improving construction efficiency and quality control. Optimizing the construction process, reducing mechanical energy consumption and manual intervention, and lowering overall construction costs while ensuring project quality, yields significant economic benefits.

[0035] Example 1: Foundation construction of small-scale storage facilities around urban residential areas A small storage facility, covering an area of ​​approximately 500 square meters, is being constructed next to a residential area in a city. The foundation is collapsible loess. There are multi-story residential buildings within 5-10 meters of the site, and construction must avoid vibration impacts on these buildings. Site pretreatment (S1): The 500 square meter construction area is divided into a 2m × 2m square grid, with a total of 125 treatment points. Uncirculated soil samples are taken at depths of 0.5m, 1.5m, and 2.5m at each point. Tests show that the natural moisture content at some points is 15-17%, the void ratio is 1.0-1.2, and the collapsibility coefficient δs is 0.03-0.05. A density distribution heat map is drawn based on the test data. Areas with lower dry density are mainly concentrated on the east side of the site. The initial pressure of the compaction equipment in these areas is adjusted to be 0.3 MPa higher than in other areas.

[0036] S2 rotary compaction treatment: A double spiral drill bit is used to pre-form pilot holes at each point. The diameter of the pilot hole is 12mm smaller than that of the probe. Cement slurry mist with a water-cement ratio of 1.0 is sprayed into the hole. After positioning the rotary compaction equipment, the support structure is deployed. The probe penetrates the soil at an initial speed of 25mm / s. The pressure is increased by 0.5MPa for every 50mm of penetration. The design final pressure value of some points on the east side of the site is higher than that of other areas. When the pressure gauge reaches the design final pressure value and the probe penetration speed is less than 2mm / min, the pressure is maintained for 45 seconds and then released. The peak pressure is maintained at the design depth and the probe is rotated back and forth 4 times.

[0037] S3 Intelligent Moisture Content Control: The ring humidity sensor detects that the moisture content of the compacted soil is 16-17%. The rotating spray device is activated to replenish water at a rate of 8L / m², using a pulsed spraying method. After about 20 minutes, the sensor detects that the moisture content has stabilized in the 18-22% range for 10 minutes, and water replenishment is stopped.

[0038] S4 Quality Monitoring: Dynamic monitoring groups are installed within 1m of each compaction point to collect data in real time; within three consecutive testing cycles, the density change rate is around 0.8%, and the vibration acceleration of surrounding residential buildings is <0.1g, indicating that the foundation treatment meets the standards; a static load test is conducted with a load of 1.2 times the design value, and the settlement meets the requirements, with no areas having local settlement exceeding 5mm.

[0039] Example 2: Foundation construction of small-scale storage facilities in an industrial park A new small storage facility is being built in the industrial park. The foundation is collapsible loess, and there are factory buildings within 10-15 meters of it, which requires a high bearing capacity of the foundation.

[0040] Site S1 pretreatment: The construction area was divided into a 2m×2m grid with a total of 100 treatment points; sampling and testing showed that the natural moisture content of most points was 19-21%, the porosity was 0.9-1.1, and the collapsibility coefficient δs was 0.02-0.04. The density distribution heat map showed that the dry density in the central part of the site was relatively low, and the initial pressure parameters in these areas were adjusted.

[0041] S2 rotary extrusion compaction treatment: After pre-forming the guide hole, spray cement slurry mist with a water-cement ratio of 0.9. The probe penetrates at an initial speed of 22 mm / s and is pressurized as required. At some points, due to the denser soil, pressurization is stopped when the probe penetration speed is lower than 2 mm / min. The pressure is maintained for 50 seconds and then released, followed by pressure holding and shaping.

[0042] S3 Intelligent Moisture Content Control: When a few points are found to have a moisture content of 23-24%, the vacuum suction device is activated and the vacuum degree is maintained at 0.07MPa. After a period of suction, the moisture content stabilizes in the range of 18-22%, and the control is stopped.

[0043] S4 Quality Monitoring: Monitoring data shows that the density change rate is <1%, the vibration acceleration of the surrounding factory buildings is <0.1g, the static load test is carried out after the foundation treatment meets the standards, and the results meet the design requirements. A digital construction log is generated after the construction is completed.

[0044] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the claims of the present invention pending approval.

Claims

1. A non-vibratory foundation construction method for collapsible loess, characterized by, The method comprises the following steps: S1, dividing the construction area into a grid, the intersection of the grid being a compaction point, detecting the initial dry density of the compaction point, drawing a density distribution thermal map according to the initial dry density, and setting the initial pressure of the compaction treatment at each compaction point according to the density distribution thermal map; S2, performing rotary compaction treatment at the compaction point according to the initial pressure, and gradiently increasing the pressure until a preset depth during the rotary compaction treatment; S3, adjusting the water content of the loess in the construction area to 18-22%; S4, monitoring the soil density and the vibration acceleration of the surrounding buildings of the compaction point and the surrounding soil in real time, and when the soil density change rate is less than 1% and the vibration acceleration is less than 0.1g for at least 3 consecutive detection periods, the foundation treatment is qualified.

2. The method for construction of a non-vibratory foundation for collapsible loess according to claim 1, characterized in that, In S1, the initial dry density of the compaction point is detected, and a density distribution thermal map is drawn according to the initial dry density At each compaction point, undisturbed soil samples are taken at depths of 0.5m, 1.5m and 2.5m for detection, a density distribution thermal map is drawn according to the detection data, and a database of the initial dry density and the optimal compaction pressure is established.

3. The method for construction of a non-vibratory foundation for collapsible loess according to claim 2, characterized in that, The detection data includes the initial dry density, the natural water content, the void ratio and the collapse coefficient δs.

4. The method for construction of a non-vibratory foundation for collapsible loess according to claim 1, characterized in that, In S2, the rotary compaction treatment is specifically as follows: The initial speed is 20-30mm / s, the pressure is increased by 0.5-1.5MPa every 50mm, and the highest pressure does not exceed 80% of the ultimate bearing capacity of the soil; When the pressure reaches the preset final pressure value or the penetration speed is lower than 2mm / min, the pressure is maintained for 30-60 seconds and then released.

5. The method for construction of a vibration-free foundation for collapsible loess according to claim 1, characterized in that, Before the rotary compaction treatment, the method further comprises: A guide hole is formed at the compaction point in advance, and the diameter of the guide hole is 10-15mm smaller than the telescopic probe used for rotary compaction treatment; A cement slurry mist is sprayed into the guide hole to form a lubricating and isolating layer, and the water-cement ratio of the slurry is 0.8-1.

2.

6. The method for construction of a vibration-free foundation for collapsible loess according to claim 1, characterized in that, In S3, the water content of the loess in the construction area is monitored by the following method: The moisture content distribution of the soil after compaction treatment is detected by the humidity sensors arranged in a ring around the compaction point, and a moisture content contour map is drawn according to the moisture content; the moisture content contour map is updated every 3 minutes, and the abnormal area is automatically marked.

7. The method for construction of a vibration-free foundation for collapsible loess according to claim 1, characterized in that, In S3, the water content is adjusted to 18-22%, specifically as follows: Before the water content adjustment, it is judged that when the similarity of the pressure-penetration curves of 5 consecutive compaction points in the same operation area is greater than 90%, batch water content adjustment can be started; If the water content is lower than 18%, water is added at a rate of 5-10L / m²; Pulsating spraying is adopted; If the water content is higher than 22%, the pore water is pumped out at a pumping rate of not more than 5L / min; When the water content is detected to be stable between 18-22% for 10 minutes, the adjustment is stopped.

8. The method for construction of a vibration-free foundation for collapsible loess according to claim 1, characterized in that, In S4, the soil density and the vibration acceleration data of the surrounding buildings of the compaction point and the surrounding soil are monitored in real time, specifically as follows: A dynamic monitoring group is buried within a range of 1m around the compaction point; The soil density and the vibration acceleration data of the surrounding buildings are converted in real time according to the monitoring data, a three-dimensional compaction cloud chart is generated by a control terminal and provided to the site technical personnel for judgment of the detection effect; When the density change rate is less than 1% and the vibration acceleration is less than 0.1g for 3 consecutive detection cycles, it is determined that the foundation treatment is up to standard; if not, repeat steps S2-S4.

9. The method for construction of a vibration-free foundation for collapsible loess according to claim 8, characterized in that, The dynamic monitoring group specifically includes: Vertical monitoring: a vibrating string pore water pressure gauge is buried at the center of the compaction point, with a range of 0-500kPa; Horizontal monitoring: micro inclinometers are arranged radially at intervals of 0.5m, with an accuracy of 0.01°; Environmental monitoring: three-phase acceleration sensors are installed at the building foundations around the construction area, with a sampling frequency of ≥50Hz.

10. The method for construction of a vibration-free foundation for collapsible loess according to claim 1, characterized in that, In S4, a static load test is also included: in the area where the foundation treatment is up to standard, the load is 1.2 times the preset value of the foundation bearing capacity; for local areas with a settlement of >5mm, supplementary grouting reinforcement is carried out.

Images