A method for trench backfill construction of building backfill engineering

Abstract

The present application relates to the technical field of excavation and filling, and discloses a fat groove backfill construction method for building backfill engineering, which comprises the following steps: obtaining the geometric characteristics of a space to be backfilled and initial rheological parameters of a filling medium; injecting the filling medium and collecting rheological data of a phase change process thereof; establishing a double-buffering space-time index structure based on a phase change gradient; using asynchronous scheduling of an active index buffer and a background overwriting buffer to match a pre-stored template to generate a synchronous pressure control instruction; and applying a low-frequency pulse pressure wave according to the pressure control instruction. The present application eliminates database read-write lock conflicts through asynchronous data processing, keeps the pressure regulation and the transient evolution law of the rheological properties of the filling medium in synchronization, destroys the internal arching structure and induces in-situ reorganization of the material by using a shear strain field, and improves the compactness of the backfill body and the interface sealing efficiency.

Description

Technical Field

[0001] This invention relates to the field of excavation and filling technology, and more specifically, to a trench backfilling construction method for building backfilling projects. Background Technology

[0002] In the current backfilling operation of the trench between the basement exterior wall and the foundation pit support structure, the backfilling quality directly affects the lateral restraint stiffness of the building foundation and the groundwater sealing efficiency. Conventional construction methods use plain soil backfilling and achieve material compaction by manual tamping or layered compaction with small machinery. As building density increases, the width of the trench continues to narrow and the depth increases. This three-dimensional spatially confined physical environment and the energy input required for material compaction create a mutual repulsion. During the gravity fall of the backfill material, the physical arching effect is formed by the friction of the side walls and the interlocking force between particles, which blocks the downward transmission of compaction energy. As a result, microscopic pores and macroscopic voids are left inside the backfill, causing uneven settlement after construction.

[0003] Due to limitations in the hardware operating environment, existing technologies improve backfilling effects by optimizing construction processes and fluid control, but there are shortcomings in the control level. For example, Chinese invention patent application CN120443662A discloses a construction method for backfilling solidified soil in narrow trenches with limited working surfaces. It reduces the risk of settlement by spatial discretization and jumping pouring sequence. Such schemes are based on the static equation of fluid mechanics and preset logic control. The core preset premise is that the solidified soil is a quasi-stable fluid. Under the condition of deep and narrow trenches, the window period for the material flow state to change to the solid phase is short and exhibits nonlinear evolution. The fixed path planning and jumping logic used cannot capture the transient instability of the internal structure of the material. When high-frequency sensors are introduced for real-time monitoring, read-write lock conflicts occur between the multidimensional feedback data stream and the control command retrieval request. The pressure regulation command cannot be synchronized with the evolution of the thixotropic properties of the material. It is difficult to eliminate the deep arching structure through dynamic energy compensation while ensuring the safety of the waterproof layer.

[0004] Therefore, how to utilize the thixotropic properties of fluid materials to achieve in-situ compaction and interface self-healing of deep backfill without generating destructive lateral peak pressure and ensuring the real-time nature of control commands has become the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention provides a trench backfilling construction method for building backfilling projects, comprising the following steps:

[0006] Step S101: Obtain the geometric feature data of the work space to be backfilled and the initial rheological parameters of the filling medium. The initial rheological parameters include the initial shear stress, initial viscosity and structural recovery rate constant of the filling medium.

[0007] Step S102: The filling medium is injected into the backfilling work space, and the rheological state data of the filling medium during the phase change process is collected in real time by the monitoring unit deployed at the boundary of the backfilling work space.

[0008] Step S103: Establish a double-buffered spatiotemporal index structure based on phase change gradient, store rheological state data in the active index buffer, and update incremental rheological data by overwriting the buffer in the background when executing a retrieval request in the active index buffer; based on the correlation analysis between the output results of the active index buffer and the initial rheological parameters, match feature vectors from the pre-stored pulse waveform template to generate pulse pressure control commands that are synchronized with the current physical state of the filling medium.

[0009] Step S104: According to the pulse pressure control command, a low-frequency pulse pressure wave is applied to the filling medium through the pressure delivery device. The shear strain field induced by the low-frequency pulse pressure wave reduces the structured viscosity of the filling medium, so that the density of the filling medium is within the preset index range.

[0010] Preferably, the process of establishing a double-buffered spatiotemporal index structure based on phase transition gradient in step S103 includes: mapping rheological state data to an active index buffer according to the time sampling period; when the retrieval request density in the active index buffer reaches a preset retrieval threshold, redirecting the subsequent incoming rheological state data to a background overwrite buffer through an asynchronous processing thread, and performing incremental updates of index nodes based on phase transition gradient vectors in the background overwrite buffer; and synchronizing the states of the active index buffer and the background overwrite buffer using a pointer switching mechanism so that the pulse pressure control command responds to the evolution of the rheological properties of the filling medium.

[0011] Preferably, the filling medium is precast fluidized solidified soil, and the structural recovery rate constant is the thixotropic characteristic value of the filling medium in step S102.

[0012] Preferably, the dominant frequency f of the low-frequency pulse pressure wave in step S104 satisfies the following formula: Where f is the dominant frequency of the pulse wave, Δη is the instantaneous rate of change of the shear viscosity of the filling medium as characterized by rheological state data, and α is the preset acoustic impedance adaptive compensation coefficient.

[0013] Preferably, the monitoring unit in step S102 includes pressure sensors and an ultrasonic rheological monitoring module that are equally spaced on the side wall of the backfilling work space.

[0014] Preferably, the correlation analysis in step S103 includes calculating the offset vector of the rheological state data relative to the initial rheological parameters, and using the offset vector to perform weighted correction on the Euclidean distance calculation result of the feature vector.

[0015] Preferably, during step S104, the driving power of the low-frequency pulse pressure wave is increased according to the real-time backfilling depth of the work space to be backfilled, so as to compensate for the energy dissipation generated by the filling medium.

[0016] Preferably, step S104 further includes using lateral pressure feedback logic to monitor the dynamic peak pressure at the boundary of the backfilling work space, and when the dynamic peak pressure exceeds a preset safety threshold, switching the low-frequency pulse pressure wave to a high-frequency low-energy control mode.

[0017] Preferably, in step S104, the high-pressure strain field generated by the low-frequency pulse pressure wave is used to allow the filling medium to penetrate into the micropores of the soil at the boundary of the backfilling work space, forming an embedded connection structure after the filling medium has solidified.

[0018] Preferably, after step S104 is completed, the wave velocity characteristic value of the solidified filling medium is obtained by the monitoring unit, and when the wave velocity characteristic value is within the preset threshold range, it is determined that the filling medium has completed self-compacting and reorganizing in the space to be backfilled.

[0019] The embodiments of the present invention have at least the following beneficial effects:

[0020] 1. In the construction of backfill trenches in building backfilling projects, low-frequency pulse pressure waves are transmitted to the fluid backfill material in the thixotropic recovery latent period through pumping pipelines, causing a shear thinning effect inside the backfill material. This mechanism destroys the dislocation locking and physical arching phenomenon between particles, and induces the deep material to undergo in-situ reorganization in a three-dimensional confined space. Under the condition of no external mechanical forced vibration, the filling and self-compacting of the micropores inside the backfill body are achieved.

[0021] 2. Combining a dual-buffered spatiotemporal index structure based on rheological phase change gradient, the processor can asynchronously process high-frequency status data returned by multi-dimensional sensors and retrieval requests for pulse control commands. This data processing mechanism eliminates read-write lock conflicts under high-concurrency overwrite conditions, ensuring that the adjustment rate of pressure wave parameters is synchronized with the transient evolution law of the rheological characteristics of backfill material, so that energy input can accurately capture the vulnerable window of material transition from fluid to solid state.

[0022] 3. By utilizing the synergistic effect of acoustic impedance adaptive compensation and flexible boundary interference control, the system adjusts the pulse drive power in real time according to the change of backfill depth to offset the energy dissipation generated by non-Newtonian fluid media. This targeted energy conduction method accelerates the coalescence and discharge of trapped bubbles at the interface and forces the fluid material to penetrate into the micropores of the soil on the side wall of the foundation pit, forming a comb-shaped interface with mechanical interlocking function, which effectively improves the sealing efficiency of the backfill area against groundwater infiltration. Attached Figure Description

[0023] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings, in which several embodiments of the invention are illustrated by way of example and not limitation, wherein:

[0024] Figure 1 This is a flowchart of the backfilling construction process for the double-buffered spatiotemporal index of the present invention.

[0025] Figure 2 This is a schematic diagram of the backfilling construction process and rheological control process of the fertilizer trench of the present invention. Detailed Implementation

[0026] The principles and spirit of the present invention will now be described with reference to several exemplary embodiments in conjunction with the accompanying drawings. It should be understood that these embodiments are provided merely to enable those skilled in the art to better understand and implement the present invention, and are not intended to limit the scope of the present invention in any way. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0027] A method for backfilling trenches in building backfilling projects includes the following steps:

[0028] Step S101: Obtain the geometric feature data of the work space to be backfilled and the initial rheological parameters of the filling medium. The initial rheological parameters include the initial shear stress, initial viscosity and structural recovery rate constant of the filling medium.

[0029] Step S102: The filling medium is injected into the backfilling work space, and the rheological state data of the filling medium during the phase change process is collected in real time by the monitoring unit deployed at the boundary of the backfilling work space.

[0030] Step S103: Establish a double-buffered spatiotemporal index structure based on phase change gradient, store rheological state data in the active index buffer, and update incremental rheological data by overwriting the buffer in the background when executing a retrieval request in the active index buffer; based on the correlation analysis between the output results of the active index buffer and the initial rheological parameters, match feature vectors from the pre-stored pulse waveform template to generate pulse pressure control commands that are synchronized with the current physical state of the filling medium.

[0031] Step S104: According to the pulse pressure control command, a low-frequency pulse pressure wave is applied to the filling medium through the pressure delivery device. The shear strain field induced by the low-frequency pulse pressure wave reduces the structured viscosity of the filling medium, so that the density of the filling medium is within the preset index range.

[0032] Preferably, the process of establishing a double-buffered spatiotemporal index structure based on phase transition gradient in step S103 includes: mapping rheological state data to an active index buffer according to the time sampling period; when the retrieval request density in the active index buffer reaches a preset retrieval threshold, redirecting the subsequent incoming rheological state data to a background overwrite buffer through an asynchronous processing thread, and performing incremental updates of index nodes based on phase transition gradient vectors in the background overwrite buffer; and synchronizing the states of the active index buffer and the background overwrite buffer using a pointer switching mechanism so that the pulse pressure control command responds to the evolution of the rheological properties of the filling medium.

[0033] Preferably, the filling medium is precast fluidized solidified soil, and the structural recovery rate constant is the thixotropic characteristic value of the filling medium in step S102.

[0034] Preferably, the dominant frequency f of the low-frequency pulse pressure wave in step S104 satisfies the following formula: Where f is the dominant frequency of the pulse wave, Δη is the instantaneous rate of change of the shear viscosity of the filling medium as characterized by rheological state data, and α is the preset acoustic impedance adaptive compensation coefficient.

[0035] Preferably, the monitoring unit in step S102 includes pressure sensors and an ultrasonic rheological monitoring module that are equally spaced on the side wall of the backfilling work space.

[0036] Preferably, the correlation analysis in step S103 includes calculating the offset vector of the rheological state data relative to the initial rheological parameters, and using the offset vector to perform weighted correction on the Euclidean distance calculation result of the feature vector.

[0037] Preferably, during step S104, the driving power of the low-frequency pulse pressure wave is increased according to the real-time backfilling depth of the work space to be backfilled, so as to compensate for the energy dissipation generated by the filling medium.

[0038] Preferably, step S104 further includes using lateral pressure feedback logic to monitor the dynamic peak pressure at the boundary of the backfilling work space, and when the dynamic peak pressure exceeds a preset safety threshold, switching the low-frequency pulse pressure wave to a high-frequency low-energy control mode.

[0039] Preferably, in step S104, the high-pressure strain field generated by the low-frequency pulse pressure wave is used to allow the filling medium to penetrate into the micropores of the soil at the boundary of the backfilling work space, forming an embedded connection structure after the filling medium has solidified.

[0040] Preferably, after step S104 is completed, the wave velocity characteristic value of the solidified filling medium is obtained by the monitoring unit, and when the wave velocity characteristic value is within the preset threshold range, it is determined that the filling medium has completed self-compacting and reorganizing in the space to be backfilled.

[0041] Example 1: When the system faces the backfilling of a narrow trench between the basement exterior wall and the support structure with a depth of 15m and a width of 0.4m, the mechanical compaction equipment cannot reach the bottom of the trench. When injecting the high-flow self-leveling medium, the bottom slurry is compressed by the hydrostatic pressure of the upper liquid column. The air bubbles with a diameter of 1mm to 5mm cannot overcome the viscous resistance and escape along the solid-liquid interface, forming a water-rich and weak interlayer at the interface between the original soil wall and the retaining wall, which causes settlement. The control system acquires the geometric feature data of the work space to be backfilled and the initial rheological parameters of the pre-prepared fluidized solidified soil filling medium. The initial rheological parameters include the initial shear stress, initial viscosity and structural recovery rate constant of the filling medium. The pumping system continuously injects the filling medium into the work space to be backfilled, and simultaneously activates the pressure sensors and ultrasonic rheological monitoring modules that are equally spaced on the side walls of the work space to be backfilled, and collects the rheological state data of the filling medium in real time during the phase change process.

[0042] The processor initializes a double-buffered spatiotemporal index structure based on phase transition gradients and maps the rheological state data returned by the ultrasonic rheological monitoring module to the active index buffer according to the time sampling period. When the retrieval request density of the active index buffer is greater than or equal to the preset retrieval threshold, the processor activates an asynchronous processing thread to redirect the subsequent incoming rheological state data to the background overwrite buffer. Simultaneously, the processor incrementally updates the index nodes in the background overwrite buffer based on the phase transition gradient vector. The states of the active index buffer and the background overwrite buffer are synchronized by a pointer switching mechanism. The control system performs correlation analysis between the output results of the active index buffer and the initial rheological parameters, calculates the offset vector of the rheological state data relative to the initial rheological parameters, and uses it to apply a weighted correction to the Euclidean distance calculation results of the feature vectors in the pre-stored pulse waveform template. This generates a pulse pressure control command synchronized with the current physical state of the filling medium. After receiving the pulse pressure control command, the control system uses a pressure delivery device to apply a low-frequency pulse pressure wave to the filling medium below the liquid surface, using the pumping pipe as a waveguide medium. According to the pulse pressure control command, the dominant frequency f of the low-frequency pulse pressure wave satisfies the formula... Where f is the main frequency of the pulse wave, Δη is the instantaneous rate of change of the shear viscosity of the filling medium as characterized by rheological state data, and α is the preset acoustic impedance adaptive compensation coefficient. The low-frequency pulse pressure wave induces a dynamic shear strain field in the backfilling space, reducing the structured viscosity of the filling medium. The control system uses lateral pressure feedback logic to monitor the dynamic peak pressure at the boundary of the backfilling space in real time. When it exceeds the preset safety threshold, the control system switches the low-frequency pulse pressure wave to a high-frequency low-energy control mode. The high-pressure strain field generated by the pressure wave drives the shear-thinned filling medium to permeate, allowing the filling medium to enter the soil pores at the boundary of the backfilling space laterally.

[0043] During the continuous fluidization operation cycle, the control system increases the driving power of the low-frequency pulse pressure wave proportionally to the real-time backfill depth of the work space to be backfilled, compensating for the sound wave energy dissipation generated by the filling medium as the depth increases. The bubbles accumulated at the interface aggregate in the alternating stress field, overcome the viscous resistance of the side wall and escape upward. When the monitoring unit obtains the wave velocity characteristic value after the filling medium has solidified, the control system verifies whether the wave velocity characteristic value is within the preset solid state threshold range. When the wave velocity characteristic value is within the preset solid state threshold range, it is determined that the filling medium has completed self-compacting and reorganizing in the work space to be backfilled and formed an embedded connection structure after solidification. The arching effect of the soil is eliminated due to the action of the shear strain field, the compaction of the backfill medium is within the preset index range, and the lateral compressive deformation of the adjacent foundation structure and waterproof layer is less than the calibrated limit value.

[0044] Example 2: To address the command delay and compaction dispersion issues caused by nonlinear rheological phase transformation in deep and narrow space backfilling of fluidized solidified soil, a test platform was constructed using a transparent acrylic simulation tank with a depth of 15m and a width of 0.4m. Ultrasonic rheological monitoring modules with a sampling rate of 1000Hz and a testing accuracy of 0.1Pa·s and dynamic pressure transmitters were evenly spaced along the sidewalls of the test platform. 15dB of random Gaussian white noise and 50Hz power frequency vibration interference were introduced into the sensor circuitry to simulate electromagnetic and mechanical disturbances at the construction site. The time sampling period of the active index buffer was determined based on the constraints of real-time data acquisition and bus bandwidth occupancy. When the structural recovery rate constant in the rheological state data indicated that the filling medium was in a gelling state, the control system reduced the time sampling period to the lower limit allowed by the hardware bandwidth according to a preset linear mapping function to avoid signal aliasing. Under standard fluid-solid transformation conditions, the control system calibrated this time sampling period to 12.5ms.

[0045] The experimental system included control group 1, control group 2, control group 3, and an experimental group with a set initial viscosity gradient variable. Control group 1 eliminated the double-buffered spatiotemporal index structure and adopted single-threaded direct overwrite logic. Control group 2 used a fixed pulse frequency and neglected adaptive calculation. The acoustic impedance adaptive compensation coefficient of control group 3 was set to 5000 Pa / s, exceeding the upper limit of the calibration range. The initial viscosities of the experimental groups were set to 15.2 Pa·s, 32.4 Pa·s, and 55.6 Pa·s, respectively. During the initial filling stage, the noisy raw rheological state data collected by the ultrasonic rheological monitoring module showed irregular fluctuations. The initial shear stress of the filling medium oscillated at high frequency in the range of 110 Pa to 145 Pa. The processor mapped the noisy raw rheological state data to the active index buffer. When the retrieval request density in the active index buffer reached the preset retrieval threshold, the background overwrite buffer took over the incremental rheological data update. The processor output transient parameters based on the pointer switching mechanism, filtered out power frequency vibration interference, and calculated the instantaneous rate of change of shear viscosity Δη at the current moment to be 24.6 Pa·s. The control system then applied the formula... The target parameters were calculated, where f is the main frequency of the pulse wave, Δη is the instantaneous change rate of shear viscosity, and α is the adaptive compensation coefficient of acoustic impedance. In the test group, the control system set α to 1200 Pa / s, and the main frequency f of the output target low-frequency pulse pressure wave was calculated to be 48.7 Hz.

[0046] The control system applied a low-frequency pulsed pressure wave (48.7 Hz) to the filling medium via a pumping pipeline, inducing a dynamic shear strain field within the filling medium. In control group one, a 245 ms command output lag caused by a read / write lock conflict resulted in a backfill density of 86.4% and a porosity of 12.3% at the undisturbed soil wall interface. In control group two, the fixed pulse frequency caused acoustic energy dissipation, resulting in a backfill density of 89.1%. In control group three, high-frequency overload caused cavitation and deterioration of the filling medium, increasing the porosity at the interface to 9.8%. In the experimental group, the low-frequency pulsed pressure wave reduced the structured viscosity of the filling medium. When the dynamic peak pressure reached the safety threshold of 0.8 MPa, the control system switched the low-frequency pulsed pressure wave to a high-frequency, low-energy control mode, driving the liquid phase to penetrate the soil pores. The backfill density of the experimental group with an initial viscosity set at 32.4 Pa•s was 9... The initial viscosity of the test group increased to 8.2% and the interfacial porosity was 1.1%. As the initial viscosity of the test group increased to a value greater than 60.0 Pa·s, the shear thinning effect showed saturation characteristics. The dynamic shear strain field could not eliminate the internal arching structure, and the compaction of the backfill decreased to 92.5%. 60.0 Pa·s was determined to be the upper limit of the working window for the initial viscosity of the filling medium under this construction method. The various physical parameters output by the test confirmed the interaction mechanism of the double-buffered spatiotemporal index structure and the pulse frequency adaptive control logic. The double-buffered asynchronous processing mechanism eliminated the read-write blockage in the rheological state data overwriting process. The frequency of the pulse pressure wave output by the control system was synchronously adjusted according to the rheological phase change process of the filling medium. This dynamic alternating stress field eliminated the arching structure of the soil in the confined space. The physical indicators such as the compaction and interfacial porosity of the filling medium after solidification met the lateral constraint requirements of the foundation engineering.

[0047] Example 3: When the system faces the backfilling control condition of a narrow, thick trench with a concurrent influx of high-frequency rheological state data, the ultrasonic rheological monitoring module transmits data at millisecond intervals, creating a risk of bus read / write blocking. The control system resolves this by configuring a preset retrieval threshold in the dual-buffered spatiotemporal index structure to trigger background overwriting. The processor obtains the maximum concurrent throughput of the current system data bus and the number of bytes of memory occupied by a single rheological state data query instruction. The control system sets the ratio of the maximum concurrent throughput to the number of bytes of memory occupied by a single rheological state data query instruction as the theoretical load limit. The control system multiplies this theoretical load limit by a preset safety margin coefficient to calculate the system load boundary quantization parameter. The control system sets this quantization parameter as the preset retrieval threshold for the active index buffer and establishes a dual-buffered spatiotemporal index structure. When the retrieval request density of this buffer is greater than or equal to the preset retrieval threshold, the asynchronous processing thread executes... The incremental data overwrite operation involves the control system extracting real-time shear stress, real-time viscosity, and real-time structural recovery rate constant from the active index buffer to form a transient observation matrix. The control system also extracts the initial shear stress, initial viscosity, and structural recovery rate constant of the filling medium to form an initial reference matrix. The processor calculates the difference between the transient observation matrix and the initial reference matrix and outputs a residual matrix that records the rheological evolution trajectory of the filling medium. The control system decomposes this residual matrix and extracts the eigenvector corresponding to the largest eigenvalue as the offset vector of the rheological state data relative to the initial rheological parameters. The specific generation mechanism of this offset vector is as follows: the real-time viscosity value is subtracted from the initial viscosity value, and the difference is divided by the initial viscosity value to obtain the relative offset percentage. If the percentage is in the range of 5% to 15%, the gain factor in the diagonal weight matrix is ​​set to 1.2. If it exceeds 15%, the gain factor is increased to 1.5 to increase the interference weight on the risk of material arching.

[0048] The weighted correction process is achieved by multiplying the original Euclidean distance value with the gain factor point by point. This ensures that during the sensitive period of rapid material thickening, the system can preferentially match long pulse waveform templates with high penetration to compensate for energy dissipation. The processor calculates the initial Euclidean distance between the real-time rheological state data features and the pre-stored pulse waveform template features. The control system converts this offset vector into a diagonal weight matrix and calculates the product of this diagonal weight matrix and the initial Euclidean distance to generate a weighted Euclidean distance. The control system selects the pre-stored pulse waveform template with the minimum weighted Euclidean distance, extracts the waveform parameters associated with this pre-stored pulse waveform template, and generates... A pulsed pressure control command synchronized with the current physical state of the filling medium; the control system outputs this pulsed pressure control command to trigger a low-frequency pulsed pressure wave, the parameter structure of which is determined by the phase transition residual change of the bottom layer of the filling medium. Through the calculation of the residual matrix and the weighted Euclidean distance, the dynamic shear strain field output by the control system corresponds to the transient structured viscosity evolution process of the filling medium in the confined space. The real-time pressure peak at the boundary of the backfilling operation space and the fluid-solid conversion rate of the filling medium are controlled by this dynamic shear strain field. The internal physical arching structure disintegrates under the intervention of alternating stress, and the final compaction of the backfill medium is within the preset index range.

[0049] Example 4: When the system faces the pre-treatment condition of using a new batch of precast fluidized solidified soil for backfilling, the control system injects the material sample of this batch into an independent constant temperature test chamber and applies multiple sets of detection sound waves step by step. The ultrasonic rheological monitoring module collects the transmission sound wave attenuation spectrum of the material at different shear rates. The processor extracts the frequency domain envelope of the transmission sound wave attenuation spectrum and integrates the characteristic parameters of the frequency domain envelope into a feature vector. The control system clusters the feature vector according to the measured shear viscosity of the material and constructs a pre-stored pulse waveform template containing the mapping relationship of discrete phase transition stages. Each pre-stored pulse waveform template consists of 3 sets of core physical parameters in the database, namely: pulse peak pressure (step range from 0.5MPa to 2.5MPa). a) Single pulse duration (step range 15ms to 60ms) and pulse interval duty cycle (set range 25% to 55%); the clustering of feature vectors is based on the viscosity envelope curve of the material under a standard environment of 20℃ as the shear rate increases from 10 revolutions per second to 500 revolutions per second, and a discrete feature library is established through 1024-point sampling; the matching process uses the digital quantity after 16-bit analog-to-digital conversion to calculate the Euclidean distance. When the calculated weighted distance is less than the judgment threshold of 0.005, the corresponding template index number is automatically called and mapped to the 4mA to 20mA control current command for driving the frequency converter; the processor writes the pre-stored pulse waveform template into the protected storage sector as the basic reference data for system calls.

[0050] Before the pumping system injects the filling medium into the backfilling space, the control system initiates the in-situ baseline calibration program. The ultrasonic rheological monitoring module emits calibration sound waves towards the unfilled trench wall. The processor records the echo travel time of the sound waves reflected between the undisturbed soil wall and the support structure, establishing an unloaded compensation baseline characterizing the acoustic impedance of the trench space. The in-situ baseline calibration program is then executed, with the monitoring unit emitting calibration ultrasonic waves towards the unfilled trench, recording the round-trip travel time between the support structures to establish the unloaded compensation baseline. After the filling medium submerges the monitoring probe, the spatial structure in the echo signal is filtered out using the unloaded compensation baseline. The acoustic energy dissipation rate β caused by particle friction inside the filling medium is extracted by analyzing the reflected component. Based on the mapping relationship between the acoustic energy dissipation rate β and the real-time backfill depth, the acoustic impedance adaptive compensation coefficient α is determined and stored in the control register as a proportional parameter for the pulse pressure control command frequency adjustment term. After the probe of the monitoring unit is submerged by the filling medium, the control system continuously emits low-amplitude test ultrasonic waves. The spatial structure reflection component in the echo signal is filtered out using the unloaded compensation baseline, and the acoustic energy dissipation rate β caused by particle friction inside the filling medium is extracted. This acoustic energy dissipation rate β satisfies the formula... ,in The initial energy for transmitting test ultrasound waves. To receive the remaining energy of the echo, the processor calculates the initial shear stress and initial viscosity of the filling medium based on the acoustic energy dissipation rate β. The relevant parameters are injected into the register of the control system as initial rheological parameters. The reference parameters of the control system and the sensor data acquisition link are in a standard ready state.

[0051] Example 5: When the system faces a sidewall boundary seepage condition requiring switching from a low-frequency pulse pressure wave to a high-frequency, low-energy control mode, the empirically estimated dynamic peak pressure boundary limit may cause the support structure to exceed its deformation limit or material to penetrate into the pores and fail. To establish engineering benchmarks for preset safety thresholds and high-frequency characteristic parameters, the control system acquires the lateral bearing modulus of adjacent foundation structures and the initial porosity of the undisturbed soil wall before fluidization operations. The processor multiplies the lateral bearing modulus by a preset soil stress attenuation coefficient and outputs a quantitative index representing the critical stress state of the physical boundary. The calibration steps for this quantitative index are as follows: The control system reads the lateral bearing modulus of the adjacent foundation structure and multiplies its value by 0.8. A safety margin factor of 5 is set as the comparison boundary value for dynamic peak pressure. The sensor sampling frequency is uniformly calibrated to 1000Hz. The acquired raw signal needs to be processed by a median filtering algorithm with an order of 32 points to remove random noise interference caused by pump pulsation at the construction site. When the filtered pressure values ​​of 5 consecutive sampling points (i.e., for a duration of 5ms) all exceed the above comparison boundary value, the comparison register outputs a high level, triggering the interrupt control logic and forcing the system to switch from low-frequency heavy-load mode to high-frequency low-energy permeability mode to protect the structural integrity of the basement exterior wall. The control system writes this quantitative index into the comparison register as the preset safety threshold for dynamic peak pressure.

[0052] During the backfilling process, when the dynamic peak pressure detected by the dynamic pressure transmitter is greater than or equal to the preset safety threshold, the control system terminates the output of the low-frequency pulse command and triggers the high-frequency low-energy control mode. The processor calculates the natural frequency of the soil skeleton based on the initial porosity, and the control system then adjusts the frequency according to the formula. Generate the target modulation frequency, where, The main frequency of the high-frequency low-energy control mode. The natural frequency of the soil skeleton is given by , k is a dimensionless resonance avoidance coefficient, and the control system drives the pressure conveying device according to the dominant frequency. The preset attenuation maintenance power outputs a high-pressure strain field to the filling medium. The high-frequency alternating stress drives the shear-thinning filling medium to overcome capillary resistance and penetrate laterally into the soil pores. The fluid-solid reorganization at the interface of the undisturbed soil wall is completed within the frequency window that deviates from the structural resonance. The lateral compressive deformation of the adjacent foundation structure is below the calibration limit.

[0053] The above description is only a few preferred embodiments of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present invention is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, technical solutions formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present invention.

Claims

1. A method for trench backfilling in building backfilling projects, characterized in that, Includes the following steps: Step S101: Obtain the geometric feature data of the work space to be backfilled and the initial rheological parameters of the filling medium. The initial rheological parameters include the initial shear stress, initial viscosity and structural recovery rate constant of the filling medium. Step S102: The filling medium is injected into the backfilling work space, and the rheological state data of the filling medium during the phase change process is collected in real time by the monitoring unit deployed at the boundary of the backfilling work space. Step S103: Establish a double-buffered spatiotemporal index structure based on phase transition gradient, store rheological state data in the active index buffer, and update incremental rheological data by overwriting the buffer in the background when executing a retrieval request in the active index buffer. Based on the correlation analysis between the output of the active index buffer and the initial rheological parameters, feature vectors are matched from the pre-stored pulse waveform template to generate pulse pressure control commands that are synchronized with the current physical state of the filling medium. Step S104: According to the pulse pressure control command, a low-frequency pulse pressure wave is applied to the filling medium through the pressure delivery device. The shear strain field induced by the low-frequency pulse pressure wave reduces the structured viscosity of the filling medium, so that the density of the filling medium is within the preset index range.

2. The trench backfilling construction method for building backfilling projects according to claim 1, characterized in that, The process of establishing a double-buffered spatiotemporal index structure based on phase transition gradient in step S103 includes: mapping rheological state data to the active index buffer according to the time sampling period; when the retrieval request density in the active index buffer reaches a preset retrieval threshold, redirecting the subsequent incoming rheological state data to the background overwrite buffer through an asynchronous processing thread, and performing incremental updates of index nodes based on the phase transition gradient vector in the background overwrite buffer; and synchronizing the states of the active index buffer and the background overwrite buffer using a pointer switching mechanism so that the pulse pressure control command responds to the evolution of the rheological properties of the filling medium.

3. The trench backfilling construction method for building backfilling projects according to claim 1, characterized in that, The filling medium is precast fluidized solidified soil, and the structural recovery rate constant is the thixotropic characteristic value of the filling medium in step S102.

4. The trench backfilling construction method for building backfilling projects according to claim 1, characterized in that, In step S104, the dominant frequency f of the low-frequency pulse pressure wave satisfies the following formula: Where f is the dominant frequency of the pulse wave, Δη is the instantaneous rate of change of the shear viscosity of the filling medium as characterized by rheological state data, and α is the preset acoustic impedance adaptive compensation coefficient.

5. A trench backfilling construction method for building backfilling projects according to claim 1, characterized in that, The monitoring unit in step S102 includes pressure sensors and an ultrasonic rheological monitoring module that are equally spaced on the side wall of the backfilling work space.

6. A method for trench backfilling construction in building backfilling projects according to claim 1, characterized in that, The correlation analysis in step S103 includes calculating the offset vector of the rheological state data relative to the initial rheological parameters, and using the offset vector to perform weighted correction on the Euclidean distance calculation results of the feature vector.

7. A trench backfilling construction method for building backfilling projects according to claim 1, characterized in that, During step S104, the driving power of the low-frequency pulse pressure wave is increased according to the real-time backfilling depth of the work space to be backfilled, in order to compensate for the energy dissipation generated by the filling medium.

8. A method for trench backfilling construction in building backfilling projects according to claim 1, characterized in that, Step S104 also includes using side pressure feedback logic to monitor the dynamic peak pressure at the boundary of the backfilling work space, and when the dynamic peak pressure exceeds a preset safety threshold, switching the low-frequency pulse pressure wave to a high-frequency low-energy control mode.

9. A method for trench backfilling construction in building backfilling projects according to claim 1, characterized in that, Step S104 utilizes the high-pressure strain field generated by low-frequency pulse pressure waves to allow the filling medium to penetrate into the micropores of the soil at the boundary of the backfilling work space, forming an embedded connection structure after the filling medium has solidified.

10. A method for trench backfilling construction in building backfilling projects according to claim 1, characterized in that, After step S104 is completed, the wave velocity characteristic value of the solidified filling medium is obtained through the monitoring unit, and when the wave velocity characteristic value is within the preset threshold range, it is determined that the filling medium has completed self-compacting and reorganizing in the space to be backfilled.

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