CN112459142A - Construction engineering supervision pile foundation defect excitation detection method - Google Patents
Construction engineering supervision pile foundation defect excitation detection method Download PDFInfo
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- CN112459142A CN112459142A CN202011411087.3A CN202011411087A CN112459142A CN 112459142 A CN112459142 A CN 112459142A CN 202011411087 A CN202011411087 A CN 202011411087A CN 112459142 A CN112459142 A CN 112459142A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
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- Piles And Underground Anchors (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
A method for detecting defects of pile foundation in construction engineering supervision comprises drilling holes in soil layer on side surface of pile foundation, arranging detection pipes in the detection holes, arranging excitation sources on top or side wall of top of pile foundation, extending detectors into the detection pipes at different depths, detecting the excitation sources to emit excitation waves, and drawing time-depth waveform diagram by signals of the detectors; and determining the defects of the pile foundation according to the time-depth oscillogram, wherein the misjudgment in the pile foundation defect detection is avoided by arranging the excitation detection holes.
Description
Technical Field
The invention relates to the technical field of pile foundation detection, in particular to a pile foundation defect excitation detection method in building engineering monitoring.
Background
The pile foundation is used for bearing and transferring the upper load of a structure, and the most common concrete pile is used at present. The concrete pile is divided into a prefabricated pile and a cast-in-place pile, the grade of the concrete pile is controlled by design indexes, and the concrete pile has clear requirements on the concrete strength and the composition of the pile body. At present, the pile foundation is widely applied to various building projects, and the pile foundation is required to be applied to improve the stability of a building structure no matter the building structure is a civil engineering structure, a marine engineering structure and a bridge structure, or a special building structure. The quality of the pile foundation directly determines the overall quality of the project, so that the scientific detection of the quality of the pile foundation is very important. The pile foundation detection is that according to the characteristics of concrete pile foundation, select reasonable pile foundation detection method for use, detect the key index that length, integrality, stability, bearing capacity etc. of stake need find out, judge whether its each item index has reached the design requirement.
The nondestructive testing technique is to directly test on the structure or drill a core sample in the structure to test the internal quality of the structure and estimate the strength and quality defects of the structure without damaging the structural members, and is suitable for quality monitoring in the engineering construction process, as well as for quality verification during the completion of the engineering and during the use of the building. Nondestructive testing has the advantages of rapidness, simplicity, convenience, intuition, no damage and the like, and is increasingly widely applied and developed in construction projects. The foundation pile nondestructive testing technology is a new field of engineering geophysical prospecting development, and is an important means for concealed engineering construction quality inspection and a main basis for construction engineering supervision quality evaluation.
The main working process of low strain reflection wave method is through strikeing the pile top, thereby produce the stress wave, then the stress wave of production propagates downwards, again along the in-process of pile body propagation, if pile foundation itself appears and is similar to the undergauge, when defects such as disconnected stake of segregation, the sectional impedance of its pile foundation itself will change, stress wave will divide into two parts like this, one of them part becomes the reflection wave upwards propagation, another part becomes the transmission wave and passes defect interface downwards propagation until reaching the pile foundation bottom then reflection, the measurement personnel just can judge the quality of pile foundation itself and calculate the length of pile foundation through the curve characteristic of accepting like this.
The high strain method is that a vertical transient impact load is applied to the pile top by a hammering system, the force acting on the pile top is close to the actual stress level of the pile, so that the pile body generates obvious acceleration and inertia force, the pile body strain is equivalent to the engineering pile strain level, the impact force generates relative displacement between pile soils, thereby the side friction resistance of the pile is fully exerted, the end resistance is correspondingly excited, force and acceleration sensors are symmetrically arranged at a certain distance from the pile top at two sides of the pile, a hammering response signal is received by a foundation pile dynamic measuring instrument, so that the bearing capacity of a single pile and the structural integrity of the pile body are calculated and analyzed,
the working principle of the ultrasonic detection technology is that according to the fluctuation theory, acoustic pipes are embedded in a pile body to be detected, high-frequency elastic pulse waves are transmitted in one pipe through an ultrasonic pulse emission source, transmitted ultrasonic waves are received in the other pipe at a corresponding height, a high-precision receiving system is used for recording, and quality defects in concrete can be judged. The prior art ultrasonic pile foundation detection methods are as CN105297786A and CN 110656665A. The ultrasonic detection method has the defects that (1) the implementation of the ultrasonic method needs to embed the sounding pipe in advance during the construction of the pile foundation, so that a detection object is limited, and the detection cost is increased; (2) because the sounding pipe is arranged in the pile body, the difficulty exists in judging the defect types of the pile foundation, such as necking, necking and the like.
The side-hole transmission wave method is a new method developed on the basis of the reflection wave method. The method is characterized in that a hammer is used for vertically knocking on the top surface of a pile to generate compression waves, the compression waves are transmitted downwards along the pile body and meet surrounding soil layers, a sensor is placed in a hole drilled beside the pile in advance to receive transmission wave signals, and therefore wave waves of different depths are read and a first arrival time-depth relation graph is drawn. And determining the depth position of the pile foundation defect according to the position of the inflection point of the time-depth relation graph. In the prior art, Shanghai university of transportation discloses that the depth of a pile bottom is detected by a side-hole transmission wave method in CN103953076A, the research institute of architectural science in Sichuan province discloses that the type and the depth of a pile body defect are determined by a side-hole transmission wave method in CN105672371A, and CN108547332A and CN108560617 also disclose that the defects of a pile foundation are detected by a side-hole transmission wave method. In the side-hole transmission wave method, because the propagation speed of compression waves in the pile body is greater than that of a soil layer, if a partial region point in a time-depth relation graph falls on the left side of a first wave travel time straight line segment, the propagation speed of the partial region in a propagation path of the partial region point is higher than that of other points, and therefore the depth of the partial region point is determined as the neck-expanding defect in the pile foundation; however, if a hard rock mass exists in a soil layer between the pile foundation and the detection hole, since the propagation speed of the compression wave in the soil is lower than that of the rock mass, partial region points in the time-depth relation graph fall on the left side of the straight line segment when the first wave travels, and therefore misjudgment of the neck-expanding defect is given.
Disclosure of Invention
The invention solves the problems in the prior art, and provides an excitation detection method for defects of a construction engineering supervision pile foundation, which comprises the following steps: (1) drilling a detection hole in a soil layer on the side surface of the pile foundation, and arranging a detection conduit in the detection hole; (2) arranging an excitation source at the top of the pile foundation or on the side wall of the top of the pile foundation; (3) extending a detector into positions at different depths in the detection conduit, and detecting an excitation wave emitted by an excitation source; (4) drawing a time-depth oscillogram through the signal of the detector; (5) determining whether the pile foundation possibly has a neck-expanding defect according to the time-depth oscillogram; (6) if the pile foundation possibly has the defect of neck expansion, arranging an excitation detection hole on the other side which is symmetrical to the detection hole by taking the pile foundation as the center; (7) arranging a detector in the excitation detection hole, and detecting the excitation wave emitted by an excitation source at the top or the top side wall of the pile foundation at the depth where the neck-expanding defect possibly exists; (8) calculating the difference value between the head wave time in the step (7) and the head wave time of the detector of the detection hole with the same depth in the step (3) as that in the step (7), judging whether the neck-expanding defect exists or not, and if the neck-expanding defect does not exist, finishing the detection; if the neck-expanding defect exists, entering the step (9); (9) and arranging the excitation source at different depths in the excitation detection hole, arranging the detector at the same depth of the excitation source in the detection hole, detecting an excitation wave signal of the excitation source, and determining the neck-expanding length of the pile foundation neck-expanding defect according to the detection signal.
In the step (1), the depth of the detection hole is 2-3 m longer than that of the pile foundation.
And (5) when part of region points in the time-depth oscillogram are positioned in a left region of the head wave travel time connecting line of the other points, determining that the pile foundation possibly has the defects of neck expansion.
In the step (6), determining a depth D = ∑ Di/n, where Di is the depth of each point located in the left region point of the head-wave travel-time connecting line of the rest points, and n is the number of the left region points located in the head-wave travel-time connecting line of the rest points; and setting the depth of the excitation detection hole to be 2-3 m longer than the depth D.
In the step (8), if the absolute value of the difference value of the head wave time is greater than or equal to a threshold value, judging that no neck-expanding defect exists; and if the absolute value of the head wave time difference is smaller than the threshold, judging that the neck-expanding defect exists.
In the step (9), the length of the neck-expanding is determined according to the following mode: arranging an excitation source at the defect-free depth of the pile body in the excitation detection hole, and arranging a detector in the detection hole at the same depth of the excitation source to detect the first wave time t 1; arranging an excitation source in an excitation detection hole to the depth D of the pile body neck-expanding defect, and arranging a detector in the detection hole to detect the first wave time t2 of the excitation source at the same depth; and calculating the length h of the expanded neck (t 2-t 1) (V1V 2)/(V2-V1), wherein V1 is the transmission speed of the excitation wave on the pile body, V2 is the transmission speed of the excitation wave on the soil layer around the pile body, and V2= (S-L)/(t 1-L/V1), wherein S is the axial distance between the detection hole and the excitation hole, and L is the diameter of the pile body.
The transmission speed V1 of the excitation wave at the pile body is determined by the following method: generating an excitation wave on the side face of the pile body through an excitation source, detecting the arrival time t of the head wave on the side face corresponding to the pile body, and determining the transmission speed V1= L/t of the excitation wave on the pile body according to the diameter L of the pile body.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments thereof for the purpose of clearly understanding the present invention, but the present invention is not limited thereto.
The invention discloses a building engineering supervision pile foundation defect excitation detection method, which comprises the following steps:
(1) drilling a detection hole in a soil layer on the side surface of the pile foundation, and arranging a detection conduit in the detection hole; (2) arranging an excitation source at the top of the pile foundation or on the side wall of the top of the pile foundation; (3) extending a detector into positions at different depths in the detection conduit, and detecting an excitation wave emitted by an excitation source; (4) drawing a time-depth oscillogram through the signal of the detector;
the drilling of pile foundation side soil layer sets up the inspection hole, and the inspection hole degree of depth can set up to 2~3m than the pile foundation degree of depth length, sets up the detection pipe in the inspection hole. The detector can extend into different depths of the detection conduit through the hanging rope, excitation waves are excited at the top of the pile or the side surface of the top of the pile through the excitation source, the detector extends into different depths of the detection conduit, and the detection excitation source emits the excitation waves; the time-depth waveform is plotted against the signal from the detector.
(5) Determining whether the pile foundation possibly has the defect of neck-expanding according to the time-depth oscillogram
The head wave travel time connecting line of the time-depth oscillogram is a straight line, and the fact that the pile body is not defective is shown. Two straight lines with different slopes exist in a head wave travel time connecting line of the time-depth oscillogram, and the pile breaking defect is found at the corner of the slope. When a part of area points in the time-depth oscillogram are located in a left area of the head wave travel time connecting line of other points, the fact that the propagation speed of a part of path in the propagation path in the part of area points is higher than that of the other points is shown, and the part of area points may have a neck-expanding defect or hard rock blocks in a soil layer between a pile foundation and a detection hole. If no partial region point is located in the left region of the head wave travel time connecting line of the rest points, no neck-expanding defect exists, and subsequent detection of the neck-expanding defect is not performed.
(6) If the pile foundation possibly has the defect of neck expansion, the other side which is symmetrical to the detection hole by taking the pile foundation as the center is provided with the excitation detection hole
Determining the depth D =sigmaDi/n, wherein Di is the depth of each point of a left area point of the head wave travel time connecting line of the rest points, and n is the number of the left area points of the head wave travel time connecting line of the rest points; the depth of the vibration excitation detection hole is 2-3 m longer than the depth D.
(7) Arranging a detector at a depth where neck-expanding defects possibly exist in the excitation detection hole, and detecting excitation waves emitted by an excitation source at the top or the side wall of the top of the pile foundation; (8) calculating the difference value of the head wave time of the step (7) and the head wave time of the detector of the detection hole with the same depth as the step (7) in the step (3), and judging whether the neck-expanding defect exists or not
And (4) for the depth of the area point on the left side of the head wave travel time connecting line of the rest points in the time-depth oscillogram in the step (3), arranging a detector at the depth of the excitation detection hole, and detecting the excitation wave emitted by the excitation source at the top or the side wall of the top of the pile foundation. And (4) calculating the average value of the detected head wave time, and calculating the difference value of the average value of the head wave time of the partial region points in the step (3). The width of the pile foundation in the neck-expanding defect is expanded towards the periphery, and the hard rock block is only positioned between the pile foundation and the soil layer between the detection holes; if the absolute value of the average value is higher than the threshold value, the propagation time of the other side of the pile foundation is different from the propagation time between the pile foundation and the detection hole, the region point caused by the hard rock block is judged, the neck-expanding defect does not exist, and the subsequent step (9) is not carried out; and (4) if the absolute value of the average value is smaller than the threshold value, the propagation time of the other side of the pile foundation is close to the propagation time between the pile foundation and the detection hole, the area point caused by the neck expanding determination is judged, and the step (9) is carried out.
(9) And arranging the excitation source at different depths in the excitation detection hole, arranging the detector at the same depth of the excitation source in the detection hole, detecting an excitation wave signal of the excitation source, and determining the neck-expanding length of the pile foundation neck-expanding defect according to the detection signal.
The neck-out length is determined according to the following: arranging an excitation source at the defect-free depth of the pile body in the excitation detection hole, and arranging a detector in the detection hole at the same depth of the excitation source to detect the first wave time t 1; arranging an excitation source in an excitation detection hole to the depth D of the pile body neck-expanding defect, and arranging a detector in the detection hole to detect the first wave time t2 of the excitation source at the same depth; and calculating the length h of the expanded neck (t 2-t 1) (V1V 2)/(V2-V1), wherein V1 is the transmission speed of the excitation wave on the pile body, V2 is the transmission speed of the excitation wave on the soil layer around the pile body, and V2= (S-L)/(t 1-L/V1), wherein S is the axial distance between the detection hole and the excitation hole, and L is the diameter of the pile body. The transmission speed V1 of the excitation wave on the pile body is determined by the following method: generating an excitation wave on the side face of the pile body through an excitation source, detecting the arrival time t of the head wave on the side face corresponding to the pile body, and determining the transmission speed V1= L/t of the excitation wave on the pile body according to the diameter L of the pile body.
The embodiments described in this specification are merely illustrative of implementations of the inventive concept and the scope of the present invention should not be considered limited to the specific forms set forth in the embodiments but rather by the equivalents thereof as may occur to those skilled in the art upon consideration of the present inventive concept.
Claims (1)
1. A construction engineering supervision pile foundation defect excitation detection method comprises the following steps: (1) drilling a detection hole in a soil layer on the side surface of the pile foundation, and arranging a detection conduit in the detection hole; (2) arranging an excitation source at the top of the pile foundation or on the side wall of the top of the pile foundation; (3) extending a detector into positions at different depths in the detection conduit, and detecting an excitation wave emitted by an excitation source; (4) drawing a time-depth oscillogram through the signal of the detector; (5) determining whether the pile foundation possibly has a neck-expanding defect according to the time-depth oscillogram; (6) if the pile foundation possibly has the defect of neck expansion, arranging an excitation detection hole on the other side which is symmetrical to the detection hole by taking the pile foundation as the center; (7) arranging a detector in the excitation detection hole, and detecting the excitation wave emitted by an excitation source at the top or the top side wall of the pile foundation at the depth where the neck-expanding defect possibly exists; (8) calculating the difference value between the head wave time in the step (7) and the head wave time of the detector of the detection hole with the same depth in the step (3) as that in the step (7), judging whether the neck-expanding defect exists or not, and if the neck-expanding defect does not exist, finishing the detection; if the neck-expanding defect exists, entering the step (9); (9) and arranging the excitation source at different depths in the excitation detection hole, arranging the detector at the same depth of the excitation source in the detection hole, detecting an excitation wave signal of the excitation source, and determining the neck-expanding length of the pile foundation neck-expanding defect according to the detection signal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011411087.3A CN112459142A (en) | 2020-12-06 | 2020-12-06 | Construction engineering supervision pile foundation defect excitation detection method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011411087.3A CN112459142A (en) | 2020-12-06 | 2020-12-06 | Construction engineering supervision pile foundation defect excitation detection method |
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| CN112459142A true CN112459142A (en) | 2021-03-09 |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007170028A (en) * | 2005-12-21 | 2007-07-05 | Takenaka Komuten Co Ltd | Pile testing method and sensor press-fitting device |
| CN101570974A (en) * | 2009-03-26 | 2009-11-04 | 浙江省建筑科学设计研究院有限公司 | Method for detecting quality of existing building foundation piles with parallel seismic method |
| CN203100704U (en) * | 2013-01-31 | 2013-07-31 | 中国地质大学（武汉） | Pressed pile shape and pile length ultrasonic detection device |
| CN105297790A (en) * | 2015-10-26 | 2016-02-03 | 四川省建筑科学研究院 | Existing engineering pile body integrity and defect type judgment method |
| CN108318584A (en) * | 2018-01-25 | 2018-07-24 | 上海市民防地基勘察院有限公司 | Single-hole sound-wave combines the method for across hole CT detections pile quality and gradient |
| CN108560617A (en) * | 2018-05-05 | 2018-09-21 | 宁波亿诺维信息技术有限公司 | A kind of pile defect detection method |
| CN108918667A (en) * | 2018-04-27 | 2018-11-30 | 河海大学常州校区 | A kind of wedge defect inspection method |
| CN111693605A (en) * | 2020-05-26 | 2020-09-22 | 浙江大学 | Vertical one-generation and multi-harvesting foundation pile sound wave velocity detection device and method |
-
2020
- 2020-12-06 CN CN202011411087.3A patent/CN112459142A/en not_active Withdrawn
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007170028A (en) * | 2005-12-21 | 2007-07-05 | Takenaka Komuten Co Ltd | Pile testing method and sensor press-fitting device |
| CN101570974A (en) * | 2009-03-26 | 2009-11-04 | 浙江省建筑科学设计研究院有限公司 | Method for detecting quality of existing building foundation piles with parallel seismic method |
| CN203100704U (en) * | 2013-01-31 | 2013-07-31 | 中国地质大学（武汉） | Pressed pile shape and pile length ultrasonic detection device |
| CN105297790A (en) * | 2015-10-26 | 2016-02-03 | 四川省建筑科学研究院 | Existing engineering pile body integrity and defect type judgment method |
| CN108318584A (en) * | 2018-01-25 | 2018-07-24 | 上海市民防地基勘察院有限公司 | Single-hole sound-wave combines the method for across hole CT detections pile quality and gradient |
| CN108918667A (en) * | 2018-04-27 | 2018-11-30 | 河海大学常州校区 | A kind of wedge defect inspection method |
| CN108560617A (en) * | 2018-05-05 | 2018-09-21 | 宁波亿诺维信息技术有限公司 | A kind of pile defect detection method |
| CN111693605A (en) * | 2020-05-26 | 2020-09-22 | 浙江大学 | Vertical one-generation and multi-harvesting foundation pile sound wave velocity detection device and method |
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Application publication date: 20210309 |