Method for controlling the verticality of a vibroflotation pile machine under a super-strong seismic belt

Abstract

The application discloses a method for controlling the verticality of a vibro-replacement stone pile machine under a super-strong earthquake zone, and the vibro-replacement stone pile machine comprises a guide rod, a shock absorber and a vibrator, and the method comprises the following steps: installing a detection element for detecting a deflection parameter of the vibrator on the shock absorber or the guide rod; penetrating a pipeline for supplying water through the vibrator and extending the pipeline from the bottom end of the vibrator; controlling the verticality of the vibrator according to the deflection parameter of the vibrator detected by the detection element during the vibration construction process of the vibrator; and when the verticality of the vibrator reaches a specified verticality range, the vibrator controls the water flow of the supplied water according to the current stratum compactness to perform the vibration hole forming construction. According to the method, the vibrator can perform the vibration hole forming construction according to the stratum condition and the required verticality, the safety of the construction is improved, the construction period is effectively shortened, and the construction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of pile driver construction technology, and in particular to a method for controlling the verticality of vibratory compaction stone pile driver construction in areas with strong earthquakes. Background Technology

[0002] Vibro-compaction is a method of foundation treatment that uses horizontal vibration of a vibro-compactor and the combined action of high-pressure water or high-pressure air to compact loose foundation soil layers; or, after drilling holes in the foundation soil layers, backfilling with stable, hard, coarse-grained materials, and then forming a reinforced structure (vibro-compacted pile) through vibration compaction, which together with the surrounding foundation soil forms a composite foundation.

[0003] During the vibro-compaction construction process, different construction methods are adopted for strata with different geological conditions. If a special stratum with a complex structure is encountered, and the construction effect cannot be guaranteed under the horizontal vibration of the vibro-compaction device, the stratum is pre-damaged by water jetting with high pressure water, which is beneficial to improve the penetration and hole-making ability of the vibro-compaction device.

[0004] However, the existing "Technical Specification for Vibro-Compaction Foundation Treatment in Hydropower and Water Conservancy Projects" (DL / T524-2016) only provides a general summary of experience based on engineering practice (the current construction level of vibro-compaction stone piles in China is within 35m, and all are shallow-hole vibro-compaction with relatively simple strata). It does not specify the appropriate water pressure for different strata. Furthermore, in earthquake-prone areas, there are often weak interlayers (such as lacustrine or marine silty clay) and relatively dense hard layers (such as sand layers or sand layers interspersed with gravel). The problems encountered in drilling these two types of strata are completely different; therefore, the above-mentioned regulations are no longer applicable.

[0005] Furthermore, during the construction of vibratory stone crushing piles, whether the vibratory compactor can meet the verticality requirements during the drilling and densification process is a crucial factor affecting the quality of the vibratory stone crushing piles. However, existing vibratory stone crushing piles using conventional guide rods (i.e., guide rods of fixed length) do not have verticality control devices. The operator's personal ability and sense of responsibility are the only way to maintain the suspension of the vibratory compactor during the vibration process. This method often results in the verticality of the vibratory compactor not meeting the requirements, requiring corrections during construction, which greatly prolongs the construction period and causes losses to the owner.

[0006] Therefore, how to construct vibro-compacted stone piles that meet the required quality in strata located in extremely strong earthquake zones is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned problems and provide a method for controlling the verticality of vibratory compaction stone pile construction in areas with strong earthquakes. This method enables the vibratory compactor to vibrate downwards into the construction stratum according to the geological conditions and the required verticality, forming vibratory compaction stone piles with stable quality during strong earthquakes. This improves the safety of vibratory compaction stone pile construction, effectively shortens the construction period, and reduces construction costs.

[0008] To achieve the above-mentioned objectives of this invention, this invention provides a method for controlling the verticality of vibro-compactor stone crushing pile construction in areas of extreme earthquakes. The vibro-compactor stone crushing pile includes a guide rod, a shock absorber, and a vibro-compactor. The method includes:

[0009] The detection element used to detect the skew parameters of the vibratory shock absorber is mounted on the shock absorber or guide rod;

[0010] The pipe used to supply water passes through the vibratory flusher and extends from the bottom of the vibratory flusher, so that the water sprayed from the bottom of the vibratory flusher during the vibratory flushing process can be used to pre-disrupt the formation at the borehole location by water flushing.

[0011] During the vibratory compaction process, the verticality of the vibratory compactor is controlled based on the tilt parameters detected by the detection element.

[0012] When the verticality of the vibratory compactor reaches the specified verticality range, the vibratory compactor controls the flow rate of the supplied water according to the current formation density to carry out vibratory compaction drilling.

[0013] Among them, the detection of the skew parameters of the vibratory impactor using detection elements includes:

[0014] The apex and azimuth angles of the shock absorber or guide rod are obtained by detecting the elements.

[0015] The obtained apex angle and azimuth angle of the shock absorber or guide rod are determined as the apex angle and azimuth angle of the vibratory impactor.

[0016] Preferably, controlling the verticality of the vibratory impactor based on the skew parameter detected by the detection element includes:

[0017] The determined apex angle and azimuth angle of the vibrator are compared with the preset threshold ranges for the apex angle and azimuth angle, respectively.

[0018] Based on the comparison results, determine whether the verticality of the vibratory impactor meets the specified verticality range.

[0019] Preferably, when the verticality of the vibratory impactor does not reach the specified verticality range, the orientation of the guide rod is adjusted according to the azimuth angle of the vibratory impactor, and the apex angle of the guide rod is adjusted according to the apex angle of the vibratory impactor, so that the verticality of the vibratory impactor meets the requirements.

[0020] During the vibratory compaction process, the flow rate of the supplied water is controlled according to the current formation density so that the vibratory compactor can complete the vibratory compaction at the target water pressure. This includes:

[0021] Obtain the current formation density during vibro-compaction;

[0022] Obtain the instantaneous drainage pressure of the supplied drainage and determine the obtained instantaneous drainage pressure as the current drainage pressure;

[0023] Based on the preset correspondence between groundwater pressure and formation density, find the target groundwater pressure corresponding to the current formation density;

[0024] Control the flow rate of the supplied water to bring the current water pressure up to the target water pressure, so that the vibratory compactor can complete the vibratory compaction operation at the target water pressure.

[0025] Preferably, obtaining the current formation density includes:

[0026] Obtain the current oscillation current of the oscillator;

[0027] Based on the preset relationship between vibratory current and formation density, find the formation density corresponding to the current vibratory current.

[0028] The found formation density is determined as the current formation density.

[0029] Preferably, obtaining the current pulse current of the oscillator includes:

[0030] Obtain the instantaneous value of the vibration current of the vibrator;

[0031] The instantaneous value of the acquired oscillation current is determined as the current oscillation current.

[0032] Alternatively, obtaining the current pulse current of the oscillator may include:

[0033] Obtain multiple instantaneous values ​​of the oscillating current of the oscillator;

[0034] The average value of the multiple instantaneous values ​​of the oscillation current is obtained by averaging the values.

[0035] The average oscillation current is determined as the current oscillation current.

[0036] Preferably, averaging the acquired instantaneous values ​​of multiple oscillation currents includes:

[0037] The n (n≥2) instantaneous values ​​of oscillating current obtained consecutively are compiled into a queue, and the n instantaneous values ​​of oscillating current in the queue are added together and the average value is taken.

[0038] Preferably, controlling the flow rate of the supplied sewage to bring the current sewage pressure to the target sewage pressure includes:

[0039] Compare the current drainage pressure with the target drainage pressure to obtain the difference between the current drainage pressure and the target drainage pressure;

[0040] Based on the difference between the current drainage pressure and the target drainage pressure, the drainage flow rate supplied by the water pump is controlled so that the current drainage pressure reaches the target drainage pressure.

[0041] Compared with existing technologies, the method for controlling the verticality of vibro-compacted stone pile driving in ultra-strong earthquake zones has the following outstanding advantages:

[0042] 1. The present invention relates to a method for controlling the verticality of vibro-compacted stone pile construction in areas of high seismic intensity. During the vibro-compacting construction of complex foundations in high-earthquake zones, the method can detect the deflection parameters of the vibro-compactor in real time and control the verticality of the vibro-compactor construction in a timely manner. This allows the vibro-compactor to vibrate downwards into the construction stratum with the required verticality, ensuring the uniformity and compactness of the formed vibro-compacted stone pile diameter, improving the safety of the vibro-compacted stone pile, and effectively shortening the construction period and reducing construction costs.

[0043] 2. During the vibro-compaction process, this invention can precisely control the supply of water pressure according to the density of different strata, so that the vibro-compactor and the appropriate water pressure work together to successfully complete the vibro-compaction construction of complex strata, thereby solving the problem of vibro-compaction construction of complex strata in strong earthquake zones.

[0044] 3. This invention averages the instantaneous values ​​of the vibratory current obtained from strata with uneven local distribution, avoiding frequent adjustments to the water supply pressure due to frequent changes in the vibratory current, ensuring stable water supply from the pump, and extending the service life of the pump.

[0045] The present invention will now be described in detail with reference to the accompanying drawings. Attached Figure Description

[0046] Figure 1 This is a perspective view of the vibratory stone crushing pile machine of the present invention (the detection element is installed on the guide rod);

[0047] Figure 2 This is a schematic diagram of the structure of the vibratory impactor, shock absorber, and guide rod of the present invention after assembly (the detection element is installed on the shock absorber);

[0048] Figure 3 This is an elevation projection view of the actual guide rod when it is tilted downwards according to the present invention;

[0049] Figure 4 This is a horizontal projection diagram of the actual guide rod being lowered at an angle according to the present invention;

[0050] Figure 5 This is a flowchart of the method for controlling the verticality of vibratory stone crushing pile construction under ultra-strong earthquake zones according to the present invention;

[0051] Figure 6 This is a schematic block diagram of the drainage control system used in the vibratory stone crushing pile machine of the present invention;

[0052] Figure 7 This is a flowchart of the method for obtaining the current formation density according to the present invention;

[0053] Figure 8 This is a flowchart of the drainage control method of the present invention. Detailed Implementation

[0054] like Figure 1 The figure shows a perspective view of the vibratory stone crushing pile machine 1000 provided by the present invention. As can be seen from the figure, the vibratory stone crushing pile machine 1000 of the present invention includes a hoisting system, a guide rod 10, a shock absorber 12, a vibratory compactor 13 and an automatic feeding system.

[0055] Specifically, the hoisting system includes the main unit of the vibratory compactor stone pile driver, a mast 11 connected to the main unit, and a main winch installed at the rear of the main unit. The guide rod 10 is hoisted via the wire rope of the main winch and the mast 11, so that the guide rod is vertically positioned under its own weight. The automatic feed system is installed at the rear of the main unit of the hoisting system and can be used as a counterweight for the main unit. It includes an air hose winch, a cable winch, and a water hose winch. These three devices are set to feed synchronously with the main winch.

[0056] Guide rod 10 is a fixed-length guide rod (i.e., a conventional guide rod), the length of which can be determined according to the actual required vibratory compaction depth. The upper connecting section is used to connect with the wire rope of the main winch device, and the lower working section is used to indirectly connect with the vibratory compactor 13. During assembly, if... Figure 2 As shown, a shock absorber 12 is installed between the working section at the lower part of the guide rod 10 and the vibratory impactor 13.

[0057] To directly control the deflection parameters of the vibratory compactor during vibratory compaction of stone piles in earthquake-prone areas, thereby producing high-quality, uniform, dense, and earthquake-resistant vibratory compacted stone piles, this invention provides a method for controlling the verticality of the vibratory compactor during construction in earthquake-prone areas. Figure 5 As shown, the method includes:

[0058] The detection element used to detect the skew parameters of the vibratory shock absorber is mounted on the shock absorber or guide rod;

[0059] The pipe used to supply water passes through the vibratory flusher and extends from the bottom of the vibratory flusher, so that the water sprayed from the bottom of the vibratory flusher during the vibratory flushing process can be used to pre-disrupt the formation at the borehole location by water flushing.

[0060] During the vibratory compaction process, the verticality of the vibratory compactor is controlled based on the tilt parameters detected by the detection element.

[0061] When the verticality of the vibratory compactor reaches the specified verticality range, the vibratory compactor controls the flow rate of the supplied water according to the current formation density to carry out vibratory compaction drilling.

[0062] Specifically, the method for controlling the verticality of vibro-compacting stone pile driver construction in ultra-strong earthquake zones according to the present invention includes:

[0063] S1. Install the detection element used to detect the skew parameters of the vibratory shock absorber on the shock absorber or guide rod;

[0064] Before vibratory compaction, the center of the hole to be vibratory compacted is located and maintained using a satellite positioning system (such as GPS or Beidou) so that the vibratory compactor on the vibratory stone crushing machine can be aligned with the hole to be constructed.

[0065] To ensure that the vibratory compactor can perform vibratory compaction with the required verticality after being aligned with the hole to be constructed, this invention installs a detection element on the upper part of the damper (i.e., near the guide rod) or on the guide rod to detect the skew parameters of the vibratory compactor, such as... Figure 1 The first detection element 101 installed on the guide rod 10, or Figure 2 The second detection element 121 installed on the upper part of the shock absorber 12 can obtain the deflection parameters of the shock absorber in real time through the detection element.

[0066] The vibratory compactor mainly consists of a housing, motor, bearing housing, bearings, main shaft, and eccentric block. The motor transmits power to the main shaft through connecting flanges and couplings, causing the main shaft to rotate. The main shaft then drives the eccentric block to rotate, generating centrifugal force, which is the excitation force of the vibratory compactor. The excitation force causes the housing to vibrate at high frequency, and the vibratory compactor performs vibratory compaction through the housing.

[0067] The inventors discovered that when the center of mass of the eccentric block of the vibratory compactor deviates from and is below the center of mass of the vibratory compactor shell, the amplitude of vibration at various points along the length of the vibratory compactor shell is distributed in a triangular pattern, and the intersection with the center line of the vibratory compactor is the zero amplitude point. In the design, the center of mass of the damper should coincide with the zero amplitude point; at this point, the damper's vibration reduction and isolation effects are optimal, and its service life is also extended. Since the upper part of the damper and the guide rod are located on the upper part of the vibratory compactor and above the zero amplitude point, the upper part and above the damper are not affected by the horizontal vibration force of the vibratory compactor during vibratory compaction. Therefore, this invention installs a detection element on the upper part of the damper (located above the center of mass of the damper) or on the guide rod (preferably located on the lower part of the guide rod near the damper). The data detected by this detection element characterizes the skew parameters of the vibratory compactor, thereby ensuring the feasibility and accuracy of verticality detection during vibratory compaction.

[0068] The present invention utilizes a detection element to detect the skew parameters of the vibratory impactor, including:

[0069] The apex and azimuth angles of the shock absorber or guide rod are obtained by detecting the elements.

[0070] The apex angle and azimuth angle of the obtained shock absorber or guide rod are determined as the apex angle and azimuth angle of the vibratory impactor.

[0071] In this invention, the detection element is a component that can detect the apex angle and azimuth angle of a component, such as a gyroscope, and can be fixed to the upper part of the shock absorber or the guide rod using existing fixing methods. The skew parameters of the vibratory shock absorber include the apex angle and azimuth angle of the shock absorber.

[0072] When the detection element is installed on the upper part of the shock absorber, the apex angle and azimuth angle detected by the detection element are considered to be the apex angle and azimuth angle of the shock absorber. When the detection element is installed on the guide rod, the apex angle and azimuth angle detected by the detection element are considered to be the apex angle and azimuth angle of the guide rod. In this invention, since the guide rod, shock absorber, and vibratory compactor are coaxial, and remain coaxial during vibratory compaction, and the detection element is installed close to the top of the vibratory compactor, the detected apex angle and azimuth angle of the shock absorber or the apex angle and azimuth angle of the guide rod are correspondingly determined as the apex angle and azimuth angle of the vibratory compactor. That is, the determined apex angle and azimuth angle of the vibratory compactor are the deflection parameters of the vibratory compactor.

[0073] In this invention, the verticality of the guide rod, shock absorber, and vibratory compactor lowered along the vertical direction is considered to be 0. That is, the guide rod, etc., lowered along the vertical direction are perpendicular to the cross-section of the vertical pile hole. When the guide rod, shock absorber, and vibratory compactor are regarded as a whole vibratory compaction assembly, such a vibratory compaction assembly is called the theoretical vibratory compaction assembly. However, during actual vibratory compaction, the vibratory compaction assembly formed by the actual guide rod, etc., will have a certain angle with the vertical line. That is, the actual vibratory compaction assembly will be somewhat deviated from the theoretical vibratory compaction assembly along the vertical direction, and the deviated angles of the actual guide rod, actual shock absorber, and actual vibratory compactor in the actual vibratory compaction assembly are the same relative to the theoretical guide rod, theoretical shock absorber, and theoretical vibratory compactor in the theoretical vibratory compaction assembly along the vertical direction. In this invention, the apex angle of the guide rod refers to the angle θ between the actual lowered (or extended) guide rod and the theoretical guide rod that should have been lowered (or extended) along the vertical direction. Correspondingly, the angle between the actual lowered shock absorber and the theoretical shock absorber is also θ. Similarly, the angle between the actual lowered vibratory impactor and the theoretical vibratory impactor is also θ (e.g., Figure 3The diagram shows the apex angle of the vibratory compactor when the actual vibratory compactor assembly is lowered at an angle. The azimuth angle of the damper, relative to the tilted (or extended) guide rod, refers to the direction projected onto the horizontal plane from the lowering direction of the actual guide rod. Using north as the reference (0° position), the angle between the reference north and the actual guide rod's lowering direction clockwise is the guide rod's azimuth angle α. Similarly, the direction projected onto the horizontal plane from the lowering direction of the actual vibratory compactor assembly, using north as the reference (0° position), is also the same as the damper's azimuth angle α. That is, the azimuth angles of the vibratory compactor and guide rod are also the same as the damper's azimuth angle α (e.g., ...). Figure 4 As shown, the azimuth angle of the actual vibratory impact assembly OA is shown during the tilted lowering, where one full clockwise rotation is 360° (the 0° position is also the 360° position). For example, the actual lowering of the vibratory impact assembly along the horizontal projection direction... Figure 4 In the OA direction (α is 290°), the azimuth angle of the shock absorber and guide rod is 290°. Correspondingly, the azimuth angle of the vibratory compactor is determined to be 290°. At this point, the actual downward direction of the vibratory compactor is northwest (northwest) 70°. However, if the shock absorber and other components are completely vertical, the apex angle of the vibratory compactor is 0°, and the azimuth angle of the vibratory compactor is 0° (i.e., the vibratory compactor assembly is in...). Figure 4 The horizontal projection is point O, which coincides with the point on the horizontal projection of the centerline of the pile hole (the centerline is along the vertical direction). This means that the vibratory compactor does not have a skew problem. In other words, the azimuth angle is used to characterize the skew direction of the vibratory compactor assembly, so as to adjust the actual lowering direction of the vibratory compactor assembly accordingly.

[0074] S2. The pipe for supplying sewage is passed through the vibratory flusher and extends from the bottom end of the vibratory flusher so that the sewage sprayed from the bottom end of the vibratory flusher during the vibratory flushing process can be used to pre-damage the formation at the borehole location by water flushing.

[0075] Because the geological structure of the vibratory compactor used in this invention is complex, in order to improve the penetration and hole-making capabilities of the vibratory compactor, a pipe for supplying water is passed through the vibratory compactor and extends from the bottom end of the vibratory compactor. This allows the water sprayed from the bottom end of the vibratory compactor to pre-damage the geological formation at the hole location, thereby improving the vibratory compaction process.

[0076] S3. During the vibratory compaction process, the verticality of the vibratory compactor is controlled according to the tilt parameter detected by the detection element. When the verticality of the vibratory compactor reaches the specified verticality range, the vibratory compactor controls the flow rate of the supplied water according to the current formation density to carry out vibratory compaction hole drilling.

[0077] During the vibratory compaction drilling process, the verticality of the vibratory compactor is controlled based on the tilt parameters detected by the detection element. When the verticality of the vibratory compactor reaches the specified verticality range, the flow rate of the supplied water is controlled according to the current soil compaction, so that the vibratory compactor can perform vibratory compaction drilling with the required verticality and target water pressure to form a crushed stone pile hole.

[0078] During the vibratory compaction drilling process, on the one hand, it is necessary to control the vibratory compactor according to the deviation parameters detected by the detection element so that the vibratory compactor can perform vibratory compaction drilling with a verticality within the specified range; on the other hand, it is also necessary to control the flow rate of the supplied water according to the current density of the stratum so that the vibratory compactor can perform vibratory compaction drilling with the target water pressure to form the crushed stone pile hole.

[0079] The specific process will be described in detail below.

[0080] S31. During the vibratory compaction process, the vibratory compactor is controlled according to the skew parameters detected by the detection element so that the vibratory compactor can perform vibratory compaction with the required verticality.

[0081] S311. During the vibratory compaction process, after determining the skew parameters of the vibratory compactor through the data detected by the detection element, it is necessary to first determine whether the verticality of the vibratory compactor reaches the specified verticality range.

[0082] To determine whether the verticality of the vibratory compactor meets the specified verticality range, the following steps can be taken:

[0083] After determining the apex angle and azimuth angle of the vibratory compactor, the determined azimuth angle is compared with a preset azimuth angle threshold range to obtain the azimuth angle comparison result. That is, by comparing the azimuth angle of the vibratory compactor with the preset azimuth angle threshold range, the skew direction of the vibratory compactor relative to the north coordinate can be obtained.

[0084] After obtaining the offset direction of the vibratory impactor relative to the north coordinate, the determined apex angle of the vibratory impactor is compared with the preset apex angle threshold range to obtain the apex angle comparison result. If the apex angle comparison result shows that the apex angle of the vibratory impactor exceeds the preset apex angle threshold range, it is determined that the verticality of the vibratory impactor has not reached the specified verticality range; if the apex angle comparison result shows that the apex angle of the vibratory impactor does not exceed the preset apex angle threshold range, it is determined that the verticality of the vibratory impactor reaches the specified verticality range, i.e., meets the requirements.

[0085] Alternatively, to determine whether the verticality of the vibratory compactor meets the specified verticality range, the following steps can also be used:

[0086] After determining the apex angle and azimuth angle of the vibratory impactor, the determined apex angle is compared with a preset apex angle threshold range to obtain the apex angle comparison result. If the apex angle comparison result shows that the apex angle of the vibratory impactor does not exceed the preset apex angle threshold range, then the verticality of the vibratory impactor is determined to meet the requirements.

[0087] If the apex angle comparison result shows that the apex angle of the vibratory impactor exceeds the preset apex angle threshold range, then it is determined that the verticality of the vibratory impactor has not reached the specified verticality range. Then, the determined azimuth angle of the vibratory impactor is compared with the preset azimuth angle threshold range to obtain the azimuth angle comparison result. That is, by comparing the azimuth angle of the vibratory impactor with the preset azimuth angle threshold range, the result of the vibratory impactor's deflection direction relative to the north coordinate can be obtained.

[0088] The lower limit of the vibratory impactor apex angle threshold range is the specified minimum apex angle of the vibratory impactor, and the upper limit of the apex angle threshold range is the specified maximum apex angle of the vibratory impactor. The minimum and maximum apex angles of the vibratory impactor can be set according to engineering practice. For example, in this invention, the minimum apex angle of the vibratory impactor is 0°, and the maximum apex angle of the vibratory impactor can be taken as 5°, that is, the threshold range of the vibratory impactor is {0, 5°}. The azimuth angle threshold range of the vibratory impactor is {0°, 360°}, with true north as 0° (which is also 360°).

[0089] S312. After determining whether the verticality of the vibratory compactor has reached the specified verticality range, the vibratory compactor is controlled according to the determination result so that the vibratory compactor can perform vibratory hole drilling construction with the required verticality.

[0090] When it is determined that the verticality of the vibratory compactor has reached the specified verticality range, there is no need to adjust the lowering direction of the vibratory compactor. That is, the vibratory compactor can continue to perform vibratory compaction with the current verticality.

[0091] When it is determined that the verticality of the vibratory compactor does not meet the specified verticality range, the lowering direction of the guide rod is adjusted according to the azimuth angle of the vibratory compactor, and the apex angle of the guide rod during lowering is adjusted according to the apex angle of the vibratory compactor to ensure that the verticality of the vibratory compactor meets the requirements, as follows:

[0092] If the verticality of the vibratory compactor does not meet the specified verticality range, the following steps can be taken during construction:

[0093] (1) Lift the guide rod to drive the vibratory impactor to lift;

[0094] (2) Heavy lifting, light striking:

[0095] After the guide rod is raised to a certain height (several meters or even tens of meters), the tension of the main winch wire rope on the guide rod and vibratory compactor should be approximately 20% of the effective weight of the vibratory compactor, at least 0.5T (this force can be directly measured by a force sensor installed on the main winch). Then, the guide rod is lowered at a relatively slow speed (no more than 2m / s). During the lowering, care should be taken to control the lowering direction and apex angle of the guide rod to control the azimuth and apex angle of the vibratory compactor, so that the vibratory compactor can perform vibratory compaction on the stratum with the required verticality. "Heavy lifting and light striking" means that during the process of lowering the guide rod by the main winch wire rope to a certain height, the wire rope still maintains a certain tension on the guide rod, so that the guide rod and other components can be lowered slowly at a certain speed.

[0096] The effective weight of the vibratory compactor is the total weight of the vibratory compactor, damper, and guide rod, minus the product of the assembled volume of these three components and the mud density. In other words, the effective weight of the vibratory compactor can be calculated using the following formula:

[0097] Effective weight of vibratory compactor = (total weight of vibratory compactor + damper + guide rod) - mud density * (total volume of vibratory compactor + damper + guide rod).

[0098] During the "heavy lifting and light drilling" process, the deviation parameters of the vibratory compactor are continuously monitored in real time. Based on the monitoring results, the guide rod is repeatedly raised and lowered until the vibratory compactor, which meets the verticality requirements, penetrates the relatively hard thin layer or squeezes out small and medium-sized pebbles. This indicates that the drilling speed of the vibratory compactor is normal, that is, the speed is considered normal when it is within the range of 0.5-2.0 m / min.

[0099] This invention employs a "heavy lifting, light striking" method to ensure the verticality of the vibratory compactor meets requirements. This solves the problem in existing technologies where, when encountering similar construction strata, a rigid approach is taken. This involves the main winch wire rope pulling the vibratory compactor up several meters or even tens of meters before completely releasing the main winch wire rope (without any tension on the vibratory compactor). The guide rod and vibratory compactor rely on the impact force generated during free fall to penetrate the strata. However, because the verticality of the vibratory compactor cannot be controlled, problems such as pile misalignment or other issues arise, such as the inability to find the pile hole or pile body after penetrating the strata, leading to construction failure.

[0100] Furthermore, if repeated attempts with "heavy lifting and light striking" fail to penetrate the stratum, the following two measures can be adopted:

[0101] (3) Replacement of vibratory compactor (testing phase): During the testing phase, priority should be given to replacing the vibratory compactor with one that is heavier and has stronger penetration (i.e., higher power) (which may include a bidirectional vibratory compactor, i.e., a horizontal and vertical bidirectional vibratory compactor). Test the formation with various types of vibratory compactors as needed to achieve matching between the formation and the vibratory compactor.

[0102] (4) Rotary drilling pilot hole (construction stage): During large-scale construction, priority should be given to moving the machine to perform rotary drilling pilot hole before continuing drilling until the hole is completed.

[0103] S32. During the vibratory compaction drilling process, when the verticality of the vibratory compactor reaches the specified verticality range, the flow rate of the supplied water should be controlled according to the current ground compaction so that the vibratory compactor can carry out vibratory compaction with the target water pressure.

[0104] When using water jets from the bottom of a vibratory compactor to perform vibratory compaction on the formation, provided the compactor meets verticality requirements, the water flow rate must be controlled according to the current formation density to ensure the vibratory compactor can perform the compaction at the target water pressure. This includes:

[0105] S321. Obtain the current ground compaction during vibro-compaction construction;

[0106] S322. Obtain the instantaneous drainage pressure of the supplied drainage and determine the obtained instantaneous drainage pressure as the current drainage pressure;

[0107] S323. Based on the preset correspondence between groundwater pressure and formation density, find the target groundwater pressure corresponding to the current formation density;

[0108] S324. Control the flow rate of the supplied water to make the current water pressure reach the target water pressure, so as to carry out vibratory flushing construction using the vibratory flushing device and the target water pressure.

[0109] The construction process will be described in detail below.

[0110] S321. Obtain the current ground compaction during vibro-compaction.

[0111] like Figure 7 As shown, obtaining the current formation density during vibro-compaction includes:

[0112] 1. Obtain the current oscillation current of the oscillator;

[0113] 2. Based on the preset relationship between vibratory current and formation density, find the formation density corresponding to the current vibratory current;

[0114] 3. Determine the found formation density as the current formation density.

[0115] like Figure 6 As shown, the vibrator 13 is connected to the controller 1 through the vibrator frequency converter cabinet 2. The vibrator frequency converter cabinet 2 and the controller 1 are connected wirelessly or wiredly.

[0116] In one embodiment of the present invention, when encountering a locally uniformly distributed stratum, the instantaneous value of the obtained oscillating current is stable. The current oscillating current of the oscillator is obtained by the following method: obtaining the instantaneous value of the oscillating current of the oscillator; and determining the obtained instantaneous value of the oscillating current as the current oscillating current.

[0117] In this implementation, the controller 1 obtains the vibration current signal of the vibrator 13 from the vibrator inverter cabinet 2 and determines the obtained vibration current as the current vibration current. Alternatively, a current detection sensor (not shown in the figure) is installed on the vibration output line of the vibrator 13 connected to the vibrator inverter cabinet 2; when the vibrator 13 is started, the current detection sensor generates a vibration current signal, which is transmitted to the controller 1 in real time via wired or wireless means. The controller 1 determines the vibration current transmitted from the current detection sensor in real time as the current vibration current. The current detection sensor can be any sensor capable of detecting current in the prior art, such as a current transformer.

[0118] In another embodiment of the present invention, when encountering locally unevenly distributed strata, the instantaneous values ​​of the acquired vibratory current jump significantly. The current vibratory current of the vibrator can be obtained by: acquiring multiple instantaneous values ​​of the vibratory current; averaging the acquired instantaneous values ​​to obtain an average vibratory current; and determining the average vibratory current as the current vibratory current. The time interval between acquiring two adjacent instantaneous values ​​of the vibratory current is equal. The method for averaging the acquired instantaneous values ​​of the vibratory current is as follows: n (n≥2) consecutively acquired instantaneous values ​​of the vibratory current are grouped into a queue, and the n instantaneous values ​​in the queue are summed and averaged; each newly acquired instantaneous value of the vibratory current is added to the tail of the queue, while the first instantaneous value is removed, forming a new queue, and the n instantaneous values ​​in the new queue are summed and averaged.

[0119] In specific implementation, the method for obtaining the instantaneous value of the oscillation current is the same as that described in the previous implementation. Specifically, a current averaging module can be set up inside the controller. The controller obtains the instantaneous value of the oscillation current from the oscillator inverter cabinet 2 or the current detection sensor. The current averaging module averages the n (n≥2) instantaneous values ​​of the oscillation current in the queue to obtain the average oscillation current. The controller determines the average oscillation current as the current oscillation current.

[0120] Specifically, based on the preset correspondence between vibratory current and formation density, the formation density corresponding to the current vibratory current is found; and the found formation density is determined as the current formation density. The specific implementation method is as follows:

[0121] The controller has a pre-set relationship between vibratory current and soil density. This relationship is obtained through testing; that is, before formal construction, test piles are built on site, and the controller analyzes the large amount of data obtained from the test piles to determine the relationship between vibratory current and soil density.

[0122] In one embodiment of the present invention, the relationship between vibratory current and formation density is shown in Table 1. Formation density is divided into three levels: soft, medium, and hard. The relationship between formation density and vibratory current for different levels is obtained through field test data.

[0123] Table 1. Correspondence between vibratory current and formation density

[0124] I<0.3Ie soft 0.3Ie <I<0.8Ie middle I>0.8Ie hard

[0125] In Table 1, Ie represents the rated current of the vibrator.

[0126] After obtaining the current vibration current, the controller determines the current formation density by looking up Table 1. For example, when the controller 1 obtains the current vibration current I = 0.3Ie, it determines the current formation density as medium by looking up Table 1.

[0127] It should be noted that Table 1 only shows one correspondence between the vibration current and the formation density. For more complex formations, the controller can obtain other more complex correspondences based on field test data.

[0128] S322. Obtain the instantaneous drainage pressure of the supplied drainage and determine the obtained instantaneous drainage pressure as the current drainage pressure;

[0129] The instantaneous sewage pressure is obtained and determined as the current sewage pressure. The specific implementation method is as follows:

[0130] like Figure 6 As shown, a water supply pressure detection sensor 41 is installed on the outlet pipe of the water pump 4 to obtain the instantaneous water pressure supplied by the water pump 4 and transmit it to the controller 1. The controller 1 determines the instantaneous water pressure transmitted from the water supply pressure detection sensor 41 as the current water pressure.

[0131] Because screw pumps have the characteristics of pulsation-free water supply pressure and stable instantaneous flow rate, this invention uses a screw pump to supply sewage. However, other pumps with pulsation-free water supply pressure and stable instantaneous flow rate can also be used, as long as the supplied sewage pressure and flow rate meet the requirements. A water supply pressure detection sensor 41 is installed on the outlet pipe of the screw pump to obtain the instantaneous sewage pressure supplied by the screw pump. The water supply pressure detection sensor 41 can be any sensor capable of detecting water pressure in the prior art. For example, a pressure transmitter can be used.

[0132] In addition, such as Figure 6 As shown, a water supply flow detection sensor 42 is also installed on the outlet pipe of water pump 4 to detect the instantaneous flow rate of water supplied by water pump 4 in real time. The water supply flow detection sensor 42 can be any sensor capable of detecting water flow rate in the prior art. For example, an electromagnetic flow meter can be used. The water supply flow detection sensor 42 transmits the detected instantaneous flow rate of water supplied by water pump 4 to controller 1, and the controller determines the instantaneous flow rate as the current flow rate.

[0133] like Figure 6 As shown, the water supply pressure detection sensor 41 and the water supply flow detection sensor 42 transmit the real-time detected instantaneous water pressure signal and instantaneous water flow signal to the remote terminal unit (RTU), and the RTU transmits the signal to the controller 1 wirelessly.

[0134] S323. Based on the preset correspondence between groundwater pressure and formation density, find the target groundwater pressure corresponding to the current formation density;

[0135] Based on the preset correspondence between groundwater pressure and formation density, the target groundwater pressure corresponding to the current formation density is found. The specific implementation method is as follows:

[0136] The controller has a pre-set relationship between water pressure and soil density. This relationship is obtained through testing; that is, test piles are built on-site before formal construction, and the controller analyzes the large amount of data obtained from the test piles to determine the relationship between water pressure and soil density.

[0137] In one embodiment of the present invention, the relationship between groundwater pressure and formation density is shown in Table 2. Formation density is divided into three levels: soft, medium, and hard. The relationship between different levels of formation density and groundwater pressure is obtained through field test data.

[0138] Table 2. Correspondence between groundwater pressure and formation density

[0139] 0.3～0.5 soft 0.5～0.7 middle 0.7～0.8 hard

[0140] Controller 1 uses lookup table 2 to find the target groundwater pressure corresponding to the current formation density. As shown in Table 2, upper and lower limits are set for the groundwater pressure corresponding to each level of formation density. For example, when controller 1 determines the current formation density to be medium using lookup table 1, it uses lookup table 2 to find the target groundwater pressure corresponding to the medium-level current formation density, which is 0.5–0.7 MPa.

[0141] It should be noted that Table 2 only shows one relationship between groundwater pressure and formation density. For more complex formations, the controller can obtain other more complex relationships based on field test data.

[0142] S324. Control the flow rate of the supplied sewage to make the current sewage pressure reach the target sewage pressure.

[0143] The method for controlling the flow rate of the supplied sewage to achieve the target sewage pressure is as follows:

[0144] Compare the current drainage pressure with the target drainage pressure to obtain the difference between the current drainage pressure and the target drainage pressure;

[0145] The controller controls the flow rate of the water pump to supply water to the drain based on the difference between the current drain pressure and the target drain pressure, so that the current drain pressure reaches the target drain pressure.

[0146] Specifically, the controller controls the flow rate of water supplied by pump 4 based on the difference between the current drainage pressure and the target drainage pressure, including: when the current drainage pressure is greater than the upper limit of the target drainage pressure, controlling pump 4 to reduce the drainage flow rate; when the current drainage pressure is less than the lower limit of the target drainage pressure, controlling pump 4 to increase the drainage flow rate; and when the current drainage pressure is within the range of the target drainage pressure, controlling pump 4 to maintain the drainage flow rate.

[0147] like Figure 6 As shown, the water pump 4 of this invention is connected to the controller 1 via a water pump frequency converter cabinet 5. The water pump frequency converter cabinet 5 and the controller 1 are connected wirelessly, but a wired connection can also be used. The controller 1 controls the rotational speed of the water pump 4 by changing the output frequency of the water pump frequency converter cabinet 5, thereby changing the flow rate of the water supplied by the water pump 4. When the flow rate of the water discharged from the water pump outlet pipe increases, the water pressure also increases; when the flow rate of the water discharged from the water pump outlet pipe decreases, the water pressure also decreases.

[0148] The following describes the process of water control during vibratory compaction using the vibratory compactor that meets verticality requirements according to the present invention:

[0149] 1. After the vibratory impactor 13 is started, the water supply pressure detection sensor 41 detects the instantaneous water pressure in real time, and the water supply flow detection sensor 42 detects the instantaneous water flow in real time.

[0150] 2. Controller 1 acquires the current vibration current, current drainage pressure, and current drainage flow rate;

[0151] 3. Controller 1 determines the current formation density corresponding to the current vibration current by looking up table 1; and determines the target groundwater pressure corresponding to the current formation density by looking up table 2.

[0152] 4. The controller 1 compares the current drainage pressure with the target drainage pressure, converts the difference signal into a control signal to control the output frequency of the water pump frequency converter cabinet 5, and changes the drainage flow rate of the water pump 4 by controlling the speed of the water pump 4, thereby changing the drainage pressure so that the current drainage pressure is within the target drainage pressure range.

[0153] In summary, the method for controlling the verticality of vibro-compacted stone pile construction in ultra-strong earthquake zones, as described in this invention, allows for real-time monitoring of vibro-compactor deviation parameters and ground compaction during vibro-compactor drilling in complex foundations within strong earthquake zones. This enables timely control of the vibro-compactor's verticality and water pressure, ensuring continuous drilling with the required verticality and target water pressure. This effectively shortens the construction period, reduces costs, and ensures high verticality of the resulting stone pile holes, guaranteeing that the subsequent stone piles meet verticality requirements and are uniform and dense, thus improving the safety and seismic performance of the vibro-compacted stone piles.

[0154] Although the present invention has been described in detail above, the present invention is not limited thereto. Those skilled in the art can make modifications based on the principles of the present invention. Therefore, all modifications made in accordance with the principles of the present invention should be understood as falling within the protection scope of the present invention.

Claims

1. A method for controlling the verticality of vibratory compaction stone pile driving under ultra-strong earthquake zones, wherein the vibratory compaction stone pile driving machine includes a guide rod, a shock absorber, and a vibratory compactor, and the method includes: The shock absorber is installed at the position where the center of mass coincides with the zero amplitude point of the vibratory impactor housing, and the detection element is installed above the center of mass of the shock absorber. The relevant data of the shock absorber detected by the detection element characterizes the skew parameters of the vibratory impactor. The pipe used to supply water passes through the vibratory flusher and extends from the bottom of the vibratory flusher, so that the water sprayed from the bottom of the vibratory flusher during the vibratory flushing process can be used to pre-disrupt the formation at the borehole location by water flushing. During the vibratory compaction process, the verticality of the vibratory compactor is controlled based on the skew parameters of the vibratory compactor characterized by the relevant data of the damper detected by the detection element. When the verticality of the vibratory compactor reaches the specified verticality range, the vibratory compactor, based on the current formation density and controlling the water flow rate, performs vibratory compaction drilling, including: The current vibratory current of the vibratory compactor, the instantaneous water pressure and flow rate of the supplied water are obtained during the construction process. Based on the preset correspondence between the vibratory current and the formation density in the controller, the formation density corresponding to the current vibratory current is found, and the found formation density is determined as the current formation density. The instantaneous groundwater pressure is determined as the current groundwater pressure. Based on the preset correspondence between groundwater pressure and formation density, the target groundwater pressure corresponding to the current formation density is found. Control the water flow rate to make the current water pressure reach the target water pressure corresponding to the current soil density, so as to complete the vibratory compaction construction by using the target water pressure corresponding to the current soil density and the vibratory compactor.

2. The method according to claim 1, wherein detecting the skew parameter of the vibratory impactor using a detection element includes: The apex and azimuth angles of the shock absorber are obtained through detection elements; The obtained apex angle and azimuth angle of the shock absorber are determined as the apex angle and azimuth angle of the vibratory impactor.

3. The method according to claim 2, wherein controlling the verticality of the vibratory impactor based on the skew parameter detected by the detection element includes: The determined apex angle and azimuth angle of the vibrator are compared with the preset threshold ranges for the apex angle and azimuth angle, respectively. Based on the comparison results, determine whether the verticality of the vibratory impactor meets the specified verticality range.

4. According to the method of claim 3, when the verticality of the vibratory impactor does not reach the specified verticality range, the orientation of the guide rod is adjusted according to the azimuth angle of the vibratory impactor, and the apex angle of the guide rod is adjusted according to the apex angle of the vibratory impactor, so that the verticality of the vibratory impactor meets the requirements.

5. The method according to claim 1, wherein obtaining the current oscillation current of the oscillator includes: Obtain the instantaneous value of the vibration current of the vibrator; The instantaneous value of the acquired oscillation current is determined as the current oscillation current.

6. The method according to claim 1, characterized in that, Obtaining the current oscillation current of the oscillator includes: Obtain multiple instantaneous values ​​of the oscillating current of the oscillator; The average value of the multiple instantaneous values ​​of the oscillation current is obtained by averaging the values. The average oscillation current is determined as the current oscillation current.

7. The method according to claim 6, wherein averaging the acquired multiple instantaneous values ​​of oscillation current includes: The n (n≥2) instantaneous values ​​of oscillating current obtained consecutively are compiled into a queue, and the n instantaneous values ​​of oscillating current in the queue are added together and the average value is taken.

8. The method according to claim 1, wherein controlling the flow rate of the supplied sewage to bring the current sewage pressure to the target sewage pressure comprises: Compare the current drainage pressure with the target drainage pressure to obtain the difference between the current drainage pressure and the target drainage pressure; Based on the difference between the current drainage pressure and the target drainage pressure, the drainage flow rate supplied by the water pump is controlled so that the current drainage pressure reaches the target drainage pressure.

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