CN110670643A - Method, device and system for detecting bearing capacity of pile group foundation and storage medium - Google Patents
Method, device and system for detecting bearing capacity of pile group foundation and storage medium Download PDFInfo
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Abstract
The application relates to a method, a device and a system for detecting bearing capacity of a pile group foundation and a storage medium. The method for detecting the bearing capacity of the pile group foundation is based on a dynamic stiffness-frequency corresponding curve obtained by applying transient impact force on the pile group foundation by a transient excitation device, obtains the dynamic stiffness corresponding to a preset frequency, and can further process the dynamic stiffness to obtain the allowable bearing capacity of the pile group foundation; wherein the dynamic stiffness is obtained in a frequency range of 8Hz to 12 Hz. The foundation pile or the platform to be detected is regarded as a rigid part, the structure is in an elastic state under a certain vibration state under the impact force, the displacement which possibly causes deformation or damage of other members on the upper part of the pier foundation is avoided, and the bearing capacity detection of the pile group foundation is realized. Based on the method, the range of foundation safety evaluation can be greatly improved, and the static bearing capacity of a newly-built foundation can be evaluated; in addition, the bearing capacity of the pile foundation in operation can be detected, and the change of the bearing capacity of the foundation can be tracked and compared.
Description
Technical Field
The application relates to the technical field of bridge foundation structure detection, in particular to a method, a device and a system for detecting bearing capacity of a pile group foundation and a storage medium.
Background
In the process of acceptance after the construction of the bridge pile foundation is finished, the integrity or the bearing capacity of the foundation pile is usually required to be detected, and the finished pile foundation can be put into use. At present, a static load test method is mostly adopted in the field to evaluate the bearing capacity of a pile foundation, and the static load test is mainly carried out on a single pile to evaluate the bearing capacity of the single pile, wherein the proportion accounts for about 1%; the static load test evaluation of the bearing capacity of the pile group foundation is difficult to operate due to the large loading tonnage, so that the static load test is rarely carried out in practical application, and certain hidden danger is buried in the actual bearing capacity of the pile group foundation. The actual bearing capacity of the foundation can be changed due to the influence of scouring, saline-alkali environment and line passing load on part of pier foundations in operation, and for the pile group foundation structure in operation, the bearing capacity evaluation of the foundation can not be realized by adopting a static load test method in a large amount, so that the evaluation of the change of the bearing capacity state of the foundation is more difficult. How to evaluate the bearing capacity of the pile group foundation quickly and continuously is an unsolved problem in the industry.
Disclosure of Invention
In view of the foregoing, there is a need to provide a method, an apparatus, a system and a storage medium for detecting bearing capacity of a pile group foundation.
In order to achieve the above object, in one aspect, an embodiment of the present application provides a method for detecting bearing capacity of a pile group foundation, which is applied to a pile group foundation detection system.
Pile group foundation detection system includes:
and the transient excitation device is used for applying transient impact force to the pile group foundation.
And the processing device is used for connecting the pile group foundation.
The method for detecting the bearing capacity of the pile group foundation comprises the following steps:
the processing device acquires a dynamic stiffness-frequency corresponding curve of a pile group foundation; and the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through a transient excitation device.
The processing device acquires dynamic stiffness corresponding to preset frequency from a dynamic stiffness-frequency corresponding curve; the preset frequency ranges from 8Hz to 12 Hz.
The processing device processes the dynamic stiffness and outputs the allowable bearing capacity of the pile group foundation.
In one embodiment, the step of acquiring a dynamic stiffness-frequency response curve of the pile group foundation by the processing device comprises:
and the processing device carries out local window wave interception according to the impact force signal and the structural response signal when the transient excitation device applies transient impact force on the pile group foundation to obtain a response signal of one period.
And the processing device obtains a dynamic stiffness-frequency corresponding curve based on the response signal.
In one embodiment, the impact force signal is obtained by processing the acceleration value of the transient excitation device by the processing device.
The structural response signal is obtained by processing the acceleration value of the pile group foundation by the processing device.
In one embodiment, the step of processing the dynamic stiffness by the processing means and outputting the allowable load bearing capacity of the pile foundation comprises:
the processing device obtains the allowable bearing capacity by taking the product of the dynamic stiffness and the index parameter.
In one embodiment, the processing device, in the step of integrating the dynamic stiffness and the index parameter and outputting the allowable bearing capacity:
the processing device obtains the allowable bearing capacity based on the following formula:
Q＝Kd×0.004/η
wherein Q represents an allowable bearing capacity, KdThe dynamic stiffness is expressed, and 0.004/eta represents an index parameter; eta is in the range of 1.2 to 1.8.
In one embodiment, the step of acquiring the dynamic stiffness corresponding to the preset frequency from the dynamic stiffness-frequency corresponding curve by the processing device comprises:
the processing device carries out wave-chopping average processing on the dynamic stiffness-frequency corresponding curve and obtains the dynamic stiffness based on the dynamic stiffness-frequency corresponding curve after the wave-chopping average processing.
In one embodiment, the step of acquiring the dynamic stiffness corresponding to the preset frequency from the dynamic stiffness-frequency corresponding curve by the processing device comprises:
the processing device intercepts a section containing preset frequency from the corresponding curve of the dynamic stiffness and the frequency.
The processing device acquires dynamic stiffness from the section.
On the other hand, this application embodiment still provides a group pile foundation bearing capacity detection device, includes:
the dynamic stiffness curve acquisition module is used for acquiring a dynamic stiffness-frequency corresponding curve of the pile group foundation; and the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through a transient excitation device.
The dynamic stiffness acquisition module is used for acquiring dynamic stiffness corresponding to preset frequency from a dynamic stiffness-frequency corresponding curve; the preset frequency ranges from 8Hz to 12 Hz.
And the bearing capacity acquisition module is used for processing dynamic stiffness and outputting the allowable bearing capacity of the pile group foundation.
In one embodiment, a system is provided, comprising:
and the transient excitation device is used for applying transient impact force on the pile group foundation.
And the processing device is used for connecting the pile group foundation and realizing the method for detecting the bearing capacity of the pile group foundation.
In one embodiment, a computer storage medium is provided, on which a computer program is stored, which when executed by a processor implements the group pile foundation bearing capacity detection method as described above.
One of the above technical solutions has the following advantages and beneficial effects:
based on a dynamic stiffness-frequency corresponding curve obtained by applying transient impact force on a pile group foundation by a transient excitation device, obtaining dynamic stiffness corresponding to preset frequency, and further processing the dynamic stiffness to obtain allowable bearing capacity of the pile group foundation; wherein the dynamic stiffness is obtained in a frequency range of 8Hz to 12 Hz. The foundation pile or the platform to be detected is regarded as a rigid part, the structure is in an elastic state under a certain vibration state under the impact force, the displacement which possibly causes deformation or damage of other members on the upper part of the pier foundation is avoided, and the bearing capacity detection of the pile group foundation is realized. Based on the method, the range of foundation safety evaluation can be greatly improved, and the static bearing capacity of a newly-built foundation can be evaluated; in addition, the bearing capacity of the pile foundation in operation can be detected, the change of the bearing capacity of the foundation can be tracked and compared, and the bearing capacity of the newly-built pile can be generally checked. In addition, the method belongs to the extension of a low strain method, and has the advantages of simple equipment, convenient operation and low detection cost.
Drawings
The foregoing and other objects, features and advantages of the application will be apparent from the following more particular description of preferred embodiments of the application, as illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings, and the drawings are not intended to be drawn to scale in actual dimensions, emphasis instead being placed upon illustrating the subject matter of the present application.
Fig. 1 is a first schematic flow chart of a method for detecting bearing capacity of a pile group foundation in one embodiment;
fig. 2 is a second schematic flow chart of a method for detecting bearing capacity of a pile group foundation according to an embodiment;
fig. 3 is a third schematic flow chart of a method for detecting bearing capacity of a pile group foundation according to an embodiment;
FIG. 4 is a schematic view of a wave-chopping average of the method for detecting bearing capacity of a pile group foundation according to an embodiment;
fig. 5 is a fourth schematic flow chart of a method for detecting bearing capacity of a pile group foundation according to an embodiment;
FIG. 6 is a diagram illustrating a dynamic stiffness-frequency response curve of a pile group foundation bearing capacity detection method according to an embodiment;
fig. 7 is a schematic structural diagram of a system of a method for detecting bearing capacity of a pile group foundation according to an embodiment;
fig. 8 is a schematic structural diagram of a transient excitation device in the pile group foundation bearing capacity detection method in one embodiment;
fig. 9 is a schematic structural diagram of a pile group foundation bearing capacity detection device in one embodiment.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element and be integral therewith, or intervening elements may also be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In 1995, the relevant ministries proposed a test procedure of 'low strain method for detecting bearing capacity' for a single pile, but because the relevant test means and analysis methods of the method are not mature, the impact force is small, the error is large and the like, the method is not included in the basic bearing capacity evaluation specification of the new edition issued in 2003. The problem that how to evaluate the bearing capacity of the foundation quickly, effectively and continuously in a tracking manner is urgently needed to be solved for constructing an early foundation and a data-deficient foundation, a foundation susceptible to scouring, a foundation with an increased operation load and a foundation with a long-term bearing capacity influenced by a saline-alkaline environment. Therefore, the embodiment of the application provides a reliable and stable method for tracking and evaluating the bearing capacity of the operating pile group foundation, has a strong practical use significance, and can solve the problems that in the traditional technology, a static load test method cannot evaluate the bearing capacity on the pile group foundation in a large range, particularly the operating foundation, and the problems that the impact force is small, the detection result is discrete, the analysis method is immature and the method is only suitable for single-pile evaluation when the bearing capacity of the pile group foundation is detected by a low-strain method.
In one embodiment, a method for detecting bearing capacity of a pile group foundation is provided, and is applied to a pile group foundation detection system.
Wherein, pile group basis detecting system includes:
and the transient excitation device is used for applying transient impact force to the pile group foundation.
And the processing device is used for connecting the pile group foundation.
As shown in fig. 1, the method for detecting the bearing capacity of the pile group foundation includes:
step S110, acquiring a dynamic stiffness-frequency corresponding curve of a pile group foundation by a processing device; and the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through a transient excitation device.
Step S120, the processing device acquires dynamic stiffness corresponding to preset frequency from a dynamic stiffness-frequency corresponding curve; the preset frequency ranges from 8Hz to 12 Hz.
And step S130, the processing device processes the dynamic stiffness and outputs the allowable bearing capacity of the pile group foundation.
Specifically, the processing device applies transient impact force on the foundation of the pile group to be tested through the transient excitation device to obtain a corresponding dynamic stiffness-frequency corresponding curve; and acquiring the dynamic stiffness corresponding to the preset frequency with the value interval of 8Hz to 12Hz in the dynamic stiffness-frequency corresponding curve, and converting the dynamic stiffness to obtain and output the allowable bearing capacity of the pile group foundation to be tested. Illustratively, the processing device can output the allowable bearing capacity of the pile group foundation to a server, a display device, an audio device, a printing device or a detection center, and the like, so as to store or display the bearing capacity of the pile group foundation, and facilitate the consulting, storing, tracking and analyzing of workers.
It should be noted that, when the transient excitation device applies the transient impact force to the geometric center of the upper structure of the pile group foundation, the processing device may obtain the dynamic stiffness-frequency corresponding curve by obtaining the impact force signal and the structural response signal and further using the existing function processing; the impact force signal can be acquired on the transient excitation device, the structural response signal can be acquired on the pile group basis, and the adopted function can be a transfer function and the like. In addition, the dynamic stiffness-frequency corresponding curve can be obtained by processing the acceleration value and the speed value when the transient excitation device applies force to the pile group foundation; specifically, the processing device can acquire through a speed sensor arranged on a pile group foundation to obtain an acceleration value, and can acquire through a speed sensor arranged on the transient excitation device to obtain the acceleration value. For example, the processing device may analyze the collected data by using the DASP software to obtain a dynamic stiffness-frequency corresponding curve. It should be noted that the transient excitation device may be a device for applying a "transient impact force" to the foundation pile or the platform, and may be mainly composed of a heavy hammer, a support and a heavy hammer control part; specifically, the weight can freely fall along the guide rail of the support from a specified height under the matching of the support and the weight control part to impact the test structure, so that the transient impact force is applied to the test structure. The processing device may be a computer device, such as a server, a laptop or a tablet computer.
The predetermined frequency may be selected in the interval of 8Hz (hertz) to 12Hz, such as 8.5Hz, 9Hz, 9.5Hz, 9.8Hz, 9.9Hz, 10Hz, 10.1Hz, 10.2Hz, 10.5Hz, 11Hz, 11.5Hz, etc. In the traditional technology, the static stiffness can be analyzed and estimated by adopting 0 frequency, and then the bearing capacity is analyzed, wherein the 0 frequency static stiffness is fitted; the pile group foundation is high in rigidity and poor in low-frequency effect, and if the frequency is calculated to be 0, the error is large. In the embodiment of the application, the dynamic stiffness is measured corresponding to the preset frequency between 8Hz and 12Hz and is not obtained by fitting; meanwhile, the preset frequency can meet the bearing capacity test of the pile group foundation through the verification and statistics of a plurality of case experiment results and practical experience. The allowable bearing capacity of the pile group foundation can be obtained by processing the dynamic stiffness corresponding to the preset frequency. Exemplarily, the dynamic stiffness can be processed by index conversion, empirical parameter weighted calculation or function calculation, and the like, so as to obtain the bearing capacity; according to the actual specification standard of the bearing capacity, the dynamic stiffness can be processed in different ways to match the corresponding specification standard, and the method is not limited specifically here.
Through a large number of tests, comparison and verification, the bearing capacity condition of the foundation, particularly the foundation with obviously low bearing capacity, can be accurately distinguished, and the potential safety hazard caused by the foundation problem in the operation of the structure is greatly reduced. Compared with the traditional testing method, the force application mode of the embodiment of the application to the foundation pile or the platform is more scientific and accurate. The original force application mode in the dynamic stiffness test process is mostly to apply test force on the surface of a foundation pile or a platform in a heavy hammer knocking mode, an initial force is manually applied in the knocking process, and meanwhile, impact equipment is difficult to reach a free-falling state in the knocking process, so that the impact force test is inaccurate, and the test cannot be completely called as transient impact force. Secondly, in the original dynamic stiffness test process, such as a high-strain method, the dynamic load of the dynamic stiffness test method needs to knock the foundation pile or the platform to a large displacement degree, but in the embodiment of the application, the tested foundation pile or the platform is regarded as a rigid part, the impact force of the rigid part enables the structure to be in an elastic state under a certain vibration state, and displacement which can cause deformation or damage of other members on the upper part of the pier foundation can not occur.
Illustratively, the processing device acquires the acceleration value from a speed sensor arranged on the pile group foundation through a wired connection or a wireless connection, and then processes the acceleration value to obtain a dynamic stiffness-frequency corresponding curve of the pile group foundation.
In one embodiment, as shown in fig. 2, the step of acquiring the dynamic stiffness-frequency corresponding curve of the pile group foundation by the processing device comprises:
and step S112, the processing device carries out local window wave interception according to the impact force signal and the structural response signal when the transient excitation device applies the transient impact force on the pile group foundation, and a response signal of one period is obtained.
And step S114, the processing device obtains a dynamic stiffness-frequency corresponding curve based on the response signal.
Specifically, the processing device collects impact force signals and structural response signals in the process that the transient excitation device applies transient impact force on the pile group foundation, carries out local window wave interception on the collected impact force signals and structural response signals, and reserves to obtain a response signal of a period unit. The local window clipping is used for clipping the acquired signal data to obtain a complete impact-response-rebound signal; the response signals include an impact force signal and a structural response signal over a corresponding period. According to the periodic response signal, a dynamic stiffness-frequency corresponding curve of a periodic signal can be obtained. Based on the method, the interference can be reduced, the response signal can be obtained by fast screening, and the acquisition efficiency of the dynamic stiffness-frequency corresponding curve is improved.
In one embodiment, the impact force signal is derived by the processing device processing acceleration values of the transient excitation device.
Specifically, the impact force signal can be obtained by collecting an acceleration value of the transient excitation device; specifically, the processing device can acquire an acceleration value or a speed value through a speed sensor arranged on the transient excitation device, and then an impact force signal is obtained. Based on this, processing apparatus accessible simple device detects and obtains the dynamic stiffness-frequency corresponding curve, reduces the degree of difficulty and the cost that detect, is favorable to the popularization of this application embodiment.
In one embodiment, the structural response signal is derived by the processing means processing acceleration values of the pile foundation.
Specifically, the structural response signal can be obtained by acquiring the acceleration value of the pile group foundation; specifically, the processing device can acquire an acceleration value or a speed value through a speed sensor arranged on the pile group foundation, and then an impact force signal is obtained. Based on this, processing apparatus accessible simple device detects and obtains the dynamic stiffness-frequency corresponding curve, reduces the degree of difficulty and the cost that detect, is favorable to the popularization of this application embodiment.
In one embodiment, as shown in fig. 3, the step of processing the dynamic stiffness by the processing means to output the allowable load bearing capacity of the pile foundation comprises:
in step S132, the processing device multiplies the dynamic stiffness by the index parameter to obtain the allowable bearing capacity.
Specifically, the allowable bearing capacity can be obtained by integrating the dynamic stiffness and the index parameter in the process of acquiring the allowable bearing capacity by the processing device. The index parameters can be used for converting the dynamic stiffness to obtain the bearing capacity; specifically, the index parameters may be obtained based on experimental or practical validation statistics; the index parameters may be different for pile group foundations of different materials or different constructions. Based on this, the embodiment of the application can adopt index parameter auxiliary calculation, and further improve the detection precision of the bearing capacity.
In one embodiment, the processing device, in the step of multiplying the dynamic stiffness by the index parameter to obtain the allowable bearing capacity:
the processing device obtains the allowable bearing capacity based on the following formula:
Q＝Kd×0.004/η
wherein Q represents an allowable bearing capacity, KdThe dynamic stiffness is expressed, and 0.004/eta represents an index parameter; eta is in the range of 1.2 to 1.8.
Specifically, Q represents the estimated allowable bearing capacity; illustratively, Q can range from 50 tons to 5000 tons. The unit of the index parameter 0.004/eta can be m (meters); wherein η may be 1.3, 1.4, 1.6 or 1.7; illustratively, the value of η may be 1.5 according to the verification statistics. Based on this, the embodiment of the application can further improve the detection precision of the bearing capacity based on the verification statistical result.
In one embodiment, the step of acquiring the dynamic stiffness corresponding to the preset frequency from the dynamic stiffness-frequency corresponding curve by the processing device comprises:
the processing device carries out wave-chopping average processing on the dynamic stiffness-frequency corresponding curve and obtains the dynamic stiffness based on the dynamic stiffness-frequency corresponding curve after the wave-chopping average processing.
Specifically, in consideration of an actual test process, a test distortion may occur; after the processing device acquires the sampled data, intercepting the force and corresponding speed response relation in a short time by using a passband method, and eliminating subsequent oscillation waves, so that the obtained dynamic stiffness has a one-to-one correspondence relation; under the condition shown in fig. 4, if the test wave has a distorted wave, the test curve is subjected to wave-chopping averaging to obtain a more accurate chopped waveform, so that the detection precision is improved. Wherein the clipping average may be used to smooth the test curve.
In one embodiment, as shown in fig. 5, the step of acquiring the dynamic stiffness corresponding to the preset frequency from the dynamic stiffness-frequency corresponding curve by the processing device includes:
in step S124, the processing device cuts out a section including a preset frequency from the stiffness-frequency correspondence curve.
In step S126, the processing device acquires the dynamic stiffness from the block section.
Specifically, the processing device may first cut out a section from the dynamic stiffness-frequency correspondence curve, and then obtain the dynamic stiffness corresponding to the preset frequency from the section. Based on this, the processing device can simplify curve data, improves the precision that dynamic stiffness obtained. The interval can be set according to actual requirements, such as 0Hz to 20Hz, 5Hz to 15Hz, or 8Hz to 12 Hz.
For example, the processing device may load "DASP" software, acquire a response signal of one period by using a specific analysis method, and connect the values to obtain a dynamic stiffness-frequency correspondence curve as shown in fig. 6. From the dynamic stiffness-frequency pairCutting out a dynamic stiffness curve corresponding to the interval of 0-10 Hz from the curve, and obtaining a dynamic stiffness K corresponding to the value of 10HzdA value; and substituting the value into the formula Q ═ KdX 0.004m/η, (η ═ 1.5); thereby obtaining the basic estimated value of allowable bearing capacity.
In one embodiment, the method for detecting the bearing capacity of the pile group foundation comprises the following steps:
s1: the method comprises the steps of applying transient impact force to the geometric center of the upper structure of the pile foundation to be tested, obtaining the acceleration value and the speed during force application, and further obtaining a dynamic stiffness-frequency corresponding curve through a specific unified analysis method.
S2: the specific unified analysis method in S1 is to perform local window clipping on the impact force signal and the structural response signal to retain one cycle of the response signal.
S3: intercepting a dynamic stiffness curve corresponding to a 0-10 Hz section from the dynamic stiffness-frequency corresponding curve to obtain the dynamic stiffness K corresponding to a 10Hz valuedA value; substituting into a formula: q ═ KdX 0.004 m/eta, and the eta value is 1.5 according to a verification statistical result. Q is the estimated allowable bearing capacity of the pile group foundation; meanwhile, Q may range between 50 tons and 5000 tons.
As shown in fig. 7 and 8, the specific implementation process is as follows: the transient excitation device 10 is provided on the upper portion of the foundation pile or platform 101, when a transient impact force is required to be applied to the foundation pile or platform 101. Firstly, leveling a leveling nut 8 at the bottom of a bracket 1, and fixing the leveling nut on a pile foundation or a platform 101 to be detected; rotating the hand winch 4, and lowering the steel wire pull rope 5 together with the release device 3 to the position above the heavy hammer 2 parked at the bottom of the support 1; centering a round hole at the bottom of the release device 3 with a pin at the tail part of the heavy hammer 2, and pressing the release device 3 downwards to enable the release device 3 to completely clamp the pin; rotating the hand winch 4 to lift the steel wire rope 5, and lifting the heavy hammer 2 together with the release device 3 upwards by the steel wire rope 5; the lifting of a weight of 200kg (kilogram) can be realized by only 1 person, and the hand winch 4 has a safe self-locking function, can not be reversed, and can release hands halfway in the lifting process. As the hand winch 4 continuously lifts the heavy hammer, the release device 3 gradually approaches the limit stop 6 arranged on the bracket guide rod 7; when the heavy hammer 2 is lifted to a designated height, the outer disk of the release device 3 is tightly attached to the baffle 6, and the outer disk of the release device 3 and the inner cylinder are fixed by being blocked by the limiting baffle 6; at the moment, the hand winch 4 is slightly rotated, the outer cylinder of the release device 3 slightly lifts by about 1cm (centimeter), the pin of the counter weight 2 which is originally clamped is loosened by the internal device of the release device 3, the counter weight 2 freely falls along the guide rod 7, the test structure is impacted, and the force is used for transient impact tamping (50kg-300 kg). After the heavy hammer 2 is collided after falling to the ground, the heavy hammer rebounds to a certain height and then stands on the ground of the foundation pile or the platform. A plurality of (4-8) speed sensors 201 are arranged on a foundation pile or a platform, and the acceleration values of the foundation pile or the platform are collected while 'instant impact force' is applied to the foundation pile group or the platform. The dynamic stiffness versus frequency data after collection and analysis can be shown in table 1.
TABLE 1
It should be understood that although the various steps in the flowcharts of fig. 1, 2, 3 and 5 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 1, 2, 3, and 5 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternatingly with other steps or at least some of the sub-steps or stages of other steps.
In one embodiment, a pile group foundation bearing capacity detection device is provided and applied to a pile group foundation detection system. Pile group foundation detection system includes:
and the transient excitation device is used for applying transient impact force to the pile group foundation.
The processing device is used for connecting the pile group foundation; and the processing device is provided with a pile group foundation bearing capacity detection device.
As shown in fig. 9, the pile group foundation bearing capacity detecting apparatus includes:
the dynamic stiffness curve acquisition module is used for acquiring a dynamic stiffness-frequency corresponding curve of the pile group foundation; and the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through a transient excitation device.
The dynamic stiffness acquisition module is used for acquiring dynamic stiffness corresponding to preset frequency from a dynamic stiffness-frequency corresponding curve; the preset frequency ranges from 8Hz to 12 Hz.
And the bearing capacity acquisition module is used for processing dynamic stiffness and outputting the allowable bearing capacity of the pile group foundation.
In one embodiment, the dynamic stiffness curve acquisition module comprises:
and the response signal acquisition unit is used for carrying out local window wave interception according to the impact force signal and the structural response signal when the transient excitation device applies transient impact force on the pile group foundation to obtain a response signal of one period.
And the curve acquisition unit is used for obtaining a dynamic stiffness-frequency corresponding curve based on the response signal.
In one embodiment, the load bearing capacity acquisition module includes:
and the index parameter unit is used for obtaining the allowable bearing capacity by taking the product of the dynamic stiffness and the index parameter.
In one embodiment, the index parameter unit obtains the allowable load capacity based on the following formula:
Q＝Kd×0.004/η
wherein Q represents an allowable bearing capacity, KdThe dynamic stiffness is expressed, and 0.004/eta represents an index parameter; eta is in the range of 1.2 to 1.8.
In one embodiment, the dynamic stiffness obtaining module includes:
and the wave chopping average unit is used for carrying out wave chopping average processing on the dynamic stiffness-frequency corresponding curve and acquiring the dynamic stiffness based on the dynamic stiffness-frequency corresponding curve after the wave chopping average processing.
In one embodiment, the dynamic stiffness obtaining module includes:
and the section intercepting unit is used for intercepting a section containing preset frequency from the dynamic stiffness-frequency corresponding curve.
And the dynamic stiffness obtaining unit is used for obtaining dynamic stiffness from the section.
For specific limitations of the pile group foundation bearing capacity detection device, reference may be made to the above limitations of the pile group foundation bearing capacity detection method, which will not be described herein again. It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation. All or part of each module in the pile group foundation bearing capacity detection device can be realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, a system is provided, comprising:
and the transient excitation device is used for applying transient impact force on the pile group foundation.
The processing device is used for connecting the pile group foundation and is used for realizing the following steps:
acquiring a dynamic stiffness-frequency corresponding curve of a pile group foundation; and the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through a transient excitation device.
Acquiring dynamic stiffness corresponding to preset frequency from a dynamic stiffness-frequency corresponding curve; the preset frequency ranges from 8Hz to 12 Hz.
And the dynamic stiffness is processed, and the allowable bearing capacity of the pile group foundation is output.
In one embodiment, the processing device is connected with the transient excitation device and the pile group foundation respectively.
In one embodiment, a computer storage medium is provided, having stored thereon a computer program that, when executed by a processor, performs the steps of:
acquiring a dynamic stiffness-frequency corresponding curve of a pile group foundation; and the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through a transient excitation device.
Acquiring dynamic stiffness corresponding to preset frequency from a dynamic stiffness-frequency corresponding curve; the preset frequency ranges from 8Hz to 12 Hz.
And the dynamic stiffness is processed, and the allowable bearing capacity of the pile group foundation is output.
For specific definition and expansion of the storage medium, reference may be made to the above definition of the pile foundation bearing capacity detection method, and details are not described here.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.
Claims (10)
1. A pile group foundation bearing capacity detection method is characterized by being applied to a pile group foundation detection system;
the pile group foundation detection system comprises:
the transient excitation device is used for applying transient impact force to the pile group foundation;
the processing device is used for connecting the pile group foundation;
the method for detecting the bearing capacity of the pile group foundation comprises the following steps:
the processing device acquires a dynamic stiffness-frequency corresponding curve of the pile group foundation; the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through the transient excitation device;
the processing device acquires dynamic stiffness corresponding to preset frequency from the dynamic stiffness-frequency corresponding curve; the value range of the preset frequency is 8Hz to 12 Hz;
and the processing device processes the dynamic stiffness and outputs the allowable bearing capacity of the pile group foundation.
2. The method according to claim 1, wherein the step of the processing device obtaining a dynamic stiffness-frequency response curve of the pile group foundation comprises:
the processing device carries out local window wave interception according to an impact force signal and a structural response signal when the transient excitation device applies transient impact force on the pile group foundation to obtain a response signal of one period;
and the processing device obtains the dynamic stiffness-frequency corresponding curve based on the response signal.
3. The method of claim 2, wherein the pile foundation bearing capacity is detected,
the impact force signal is obtained by processing the acceleration value of the transient excitation device by the processing device;
the structural response signal is obtained by processing the acceleration value of the pile group foundation by the processing device.
4. The method of claim 1, wherein the step of processing the dynamic stiffness and outputting the allowable bearing capacity of the pile foundation by the processing device comprises:
and the processing device is used for obtaining the allowable bearing capacity by multiplying the dynamic stiffness and the index parameter.
5. The method according to claim 4, wherein the processing device, in the step of integrating the dynamic stiffness with an index parameter and outputting the allowable bearing capacity:
the processing device obtains the allowable bearing capacity based on the following formula:
Q＝Kd×0.004/η
wherein Q represents the allowable bearing capacity, KdRepresenting the dynamic stiffness, and 0.004/eta representing the index parameter; the value range of the eta is 1.2 to 1.8.
6. A method for detecting bearing capacity of a pile group foundation according to any one of claims 1 to 5, wherein the step of obtaining the dynamic stiffness corresponding to the preset frequency from the dynamic stiffness-frequency corresponding curve by the processing device comprises:
and the processing device carries out wave-chopping average processing on the dynamic stiffness-frequency corresponding curve and acquires the dynamic stiffness based on the dynamic stiffness-frequency corresponding curve after the wave-chopping average processing.
7. A method for detecting bearing capacity of a pile group foundation according to any one of claims 1 to 5, wherein the step of obtaining the dynamic stiffness corresponding to the preset frequency from the dynamic stiffness-frequency corresponding curve by the processing device comprises:
the processing device intercepts a section containing the preset frequency from the dynamic stiffness-frequency corresponding curve;
the processing device acquires the dynamic stiffness from the block section.
8. A group pile foundation bearing capacity detection device is characterized by being applied to a group pile foundation detection system;
the pile group foundation detection system comprises:
the transient excitation device is used for applying transient impact force to the pile group foundation;
the processing device is used for connecting the pile group foundation; the processing device is internally provided with the pile group foundation bearing capacity detection device;
pile group foundation bearing capacity detection device includes:
the dynamic stiffness curve acquisition module is used for acquiring a dynamic stiffness-frequency corresponding curve of the pile group foundation; the dynamic stiffness-frequency corresponding curve is obtained by applying transient impact force to the pile group foundation through the transient excitation device;
the dynamic stiffness acquisition module is used for acquiring dynamic stiffness corresponding to preset frequency from the dynamic stiffness-frequency corresponding curve; the value range of the preset frequency is 8Hz to 12 Hz;
and the bearing capacity acquisition module is used for processing the dynamic stiffness and outputting the allowable bearing capacity of the pile group foundation.
9. A system, comprising:
the transient excitation device is used for applying transient impact force on the pile group foundation;
processing means for connecting said pile foundations and for implementing a method of detecting the bearing capacity of a pile foundation according to any one of claims 1 to 7.
10. A computer storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements a method of pile foundation load bearing detection according to any one of claims 1 to 7.
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