CN111560995A

CN111560995A - Device and method for testing internal force of cast-in-place pile by using optical fiber

Info

Publication number: CN111560995A
Application number: CN202010468428.4A
Authority: CN
Inventors: 郑建国; 刘争宏; 于永堂; 张龙; 黄晓维
Original assignee: Machinery Industry Survey Design And Research Institute Co ltd
Current assignee: Machinery Industry Survey Design And Research Institute Co ltd
Priority date: 2020-05-28
Filing date: 2020-05-28
Publication date: 2020-08-21
Anticipated expiration: 2040-05-28
Also published as: CN111560995B

Abstract

The invention discloses a device and a method for testing the internal force of a cast-in-place pile by using optical fibers, wherein the device comprises a splitter ring part, a measuring tube, a grouting tube, an optical fiber structure and an optical fiber positioner, the optical fiber structure comprises an optical fiber implanting plug and optical fibers, the splitter ring part comprises a splitter ring, an upper connector and a lower connector, the optical fiber implanting plug comprises a plug block body, an upper threaded connector and a plug, the optical fiber positioner comprises an upper connector part and a positioning body, and a vertical channel and a telescopic tooth structure are arranged in the positioning body; the method comprises the following steps: firstly, manufacturing a shunt ring part; secondly, mounting a measuring pipe, a grouting pipe and a shunt ring part; thirdly, hoisting the shunt ring, the measuring pipe and the grouting pipe; fourthly, implanting optical fibers; fifthly, grouting; sixthly, collecting a pile head lead and an initial value of the cast-in-place pile; seventhly, load loading and strain data acquisition and processing of the cast-in-place pile; and eighthly, acquiring the internal force of the cast-in-place pile. The invention has reasonable design, little influence on the construction of the cast-in-place pile and improves the test accuracy.

Description

Device and method for testing internal force of cast-in-place pile by using optical fiber

Technical Field

The invention belongs to the technical field of testing of internal force of a cast-in-place pile, and particularly relates to a device and a method for testing the internal force of the cast-in-place pile by using optical fibers.

Background

The cast-in-place pile is widely applied to foundation engineering of engineering such as industrial and civil buildings, ports, railways, highways and the like, the internal force test is a direct basis for optimizing the design of the pile foundation, and the good pile body internal force test can save a large amount of construction funds for the country and bring huge economic and social benefits. The optical fiber in the distributed optical fiber sensing technology is a transmitter and a sensor, and the deformation condition of each point on the optical fiber can be continuously monitored by using the scattering of light in the optical fiber. By utilizing the characteristics of the distributed optical fiber sensing technology, the detection of the continuous deformation of the pile body of the cast-in-place pile can be realized by implanting the optical fiber into the cast-in-place pile body and generating the cooperative deformation with the cast-in-place pile body, thereby achieving the purpose of testing the internal force of the pile foundation of the cast-in-place pile. In order to achieve the above purpose, it is necessary to develop a device and a method for testing the internal force of a bored concrete pile by using an optical fiber, which facilitate the implantation of the optical fiber, have little influence on the construction of the bored concrete pile, and ensure the accuracy of the internal force test of the bored concrete pile.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a device for testing the internal force of a cast-in-place pile by using optical fibers, which is reasonable in design, convenient and fast to construct, convenient for implanting the optical fibers, small in influence on the construction of the cast-in-place pile and capable of ensuring the accurate internal force test of the cast-in-place pile.

In order to solve the technical problems, the invention adopts the technical scheme that: the utility model provides an utilize device of optic fibre test bored concrete pile internal force which characterized in that: the optical fiber implanting plug comprises a splitter ring part arranged in a cast-in-place pile, a measuring tube and a grouting tube which are arranged on the splitter ring part, an optical fiber structure arranged in the measuring tube and an optical fiber positioner arranged at the bottom of the splitter ring part, wherein the optical fiber structure comprises an optical fiber implanting plug and optical fibers which are arranged on the optical fiber implanting plug in a penetrating manner and distributed along the measuring tube, and the optical fiber implanting plug extends into the optical fiber positioner;

the optical fiber implanting plug comprises a plug block body, an upper threaded connector and a plug, wherein the upper threaded connector is arranged on the plug block body, the plug is arranged at the bottom of the plug block body, a U-shaped groove is formed in the plug block body, optical fibers are distributed in the measuring tube in a U shape;

the optical fiber positioner comprises an upper joint part and a positioning body connected with the upper joint part, wherein an optical fiber is arranged in the positioning body and provided with a vertical channel for inserting the optical fiber into the plug and a telescopic tooth structure for positioning the plug, the upper joint part is connected with the lower joint, a positioning groove matched with the telescopic tooth structure is arranged on the plug, and cement slurry is filled in the measuring pipe.

The device for testing the internal force of the cast-in-place pile by using the optical fiber is characterized in that: the outer diameter of the shunt ring is the same as the inner diameter of a reinforcement cage required by the cast-in-place pile, and the shunt ring is of a hollow structure;

the number of the upper joints is three, the three upper joints are uniformly distributed along the half circumference of the shunt ring, the three upper joints are respectively a first measuring pipe joint, a second measuring pipe joint and a grouting connector, the number of the lower joints is two, the two lower joints are symmetrically distributed about the center of the shunt ring, and the two lower joints are respectively a first positioning joint and a second positioning joint;

the first measuring pipe joint and the first positioning joint are positioned on the same straight line and are communicated with the splitter ring, the second measuring pipe joint and the second positioning joint are positioned on the same straight line and are communicated with the splitter ring, and the grouting connector is communicated with the splitter ring.

The device for testing the internal force of the cast-in-place pile by using the optical fiber is characterized in that: the positioning body is provided with a transition part at the top part close to the upper joint part, the section of the transition part is gradually reduced from the upper joint part to the vertical channel, and the upper joint part is in threaded connection with the lower joint;

the telescopic tooth structure comprises a first telescopic tooth component and a second telescopic tooth component which are symmetrically arranged in the positioning body and extend into the vertical channel, the first telescopic tooth component and the second telescopic tooth component are identical in structure, the first telescopic tooth component and the second telescopic tooth component comprise a vertical portion and a plurality of tooth portions arranged along the height direction of the vertical portion, and a spring component connected between the vertical portion and the positioning body.

The device for testing the internal force of the cast-in-place pile by using the optical fiber is characterized in that: the positioning body is internally provided with an installation cavity for installing the spring parts, the number of the spring parts is two, the two spring parts are uniformly distributed along the height direction of the vertical part, each spring part comprises a guide pillar arranged on the positioning body and a spring sleeved on the guide pillar and connected with the vertical part, and one end of the spring, which is far away from the vertical part, is fixedly connected with the positioning body;

the quantity of tooth portion is three, and is three tooth portion is first tooth portion, second tooth portion and third tooth portion respectively, the terminal surface that vertical portion was kept away from to first tooth portion, second tooth portion and third tooth portion is the conical surface, length that first tooth portion, second tooth portion and third tooth portion lower part were greater than first tooth portion, second tooth portion and the length on third tooth portion upper portion respectively, encloses between two first tooth portions, between two second tooth portions and two third tooth portions and establishes into the frustum chamber that supplies constant head tank male in the plug.

The device for testing the internal force of the cast-in-place pile by using the optical fiber is characterized in that: the quantity of constant head tank is a plurality of, and is a plurality of the constant head tank is laid along the plug direction of height, the constant head tank is from top to bottom degree of depth crescent, the U-shaped groove extends to the central point that the plug block was followed width direction and puts.

And the upper threaded joint is in threaded connection with a plurality of sections of steel rods.

Meanwhile, the invention also discloses a method for testing the internal force of the cast-in-place pile by using the optical fiber, which has simple steps, reasonable design and convenient implementation, and is characterized by comprising the following steps:

step one, manufacturing a shunt ring component:

step 101, manufacturing a shunt ring;

step 102, welding a lower joint at the bottom of the shunt ring; the number of the lower joints is two, the two lower joints are symmetrically arranged around the center of the shunt ring, and the two lower joints are respectively marked as a first positioning joint and a second positioning joint;

103, welding an upper joint on the top of the shunt ring to complete the manufacture of the shunt ring component; the number of the upper joints is three, the three upper joints are uniformly distributed along the half circumference of the shunt ring, and the three upper joints are respectively marked as a first pipe measuring joint, a second pipe measuring joint and a grouting connector;

step two, the installation of survey pipe, slip casting pipe and reposition of redundant personnel ring part:

step 201, respectively installing a pipe measuring section and a grouting pipe section in a multi-section reinforcement cage;

202, installing a shunt ring at the bottom of a section of reinforcement cage, installing pipe sections on a first pipe measuring joint and a second pipe measuring joint, installing a grouting pipe section on a grouting connecting joint, installing an upper pipe measuring joint at the upper end of the pipe measuring section, and installing a grouting pipe joint at the upper end of the grouting pipe section; the outer side wall of the shunt ring is welded with the inner side wall of a section of reinforcement cage;

step 203, respectively installing optical fiber positioners on a first positioning connector and a second positioning connector at the bottom of the shunt ring; the distance between the bottom of the optical fiber positioner and the bottom of the section of reinforcement cage is 1-2 m;

step three, hoisting the shunt ring, the measuring pipe and the grouting pipe:

step 301, hoisting the shunt ring and the optical fiber positioner into a bored concrete pile drill hole along with a section of reinforcement cage;

step 302, hoisting the pipe measuring section and the grouting pipe section to a bored pile drill hole along with a reinforcement cage, and completing installation of the pipe measuring and grouting pipes;

step 303, pouring concrete into the bored pile to form a bored pile; wherein, the measuring pipe and the grouting pipe extend out of the cast-in-place pile;

step four, implanting optical fibers:

step 401, forming a U-shaped groove on the optical fiber implanting plug;

step 402, threading an optical fiber into the U-shaped groove, and fixing the optical fiber by glue; a light-transmitting pen is connected with two extending ends of the optical fiber through an optical fiber jumper wire to judge that the optical fiber is normal; wherein, two ends of the optical fiber respectively extend out of the U-shaped groove;

step 403, connecting a section of steel rod to the upper threaded connector on the optical fiber implanting plug;

404, putting the optical fiber down to the measuring tube along with the first section of steel rod and the optical fiber implanting plug;

step 405, when the top of the first section of steel rod is lowered to the position where the distance between the top of the first section of steel rod and the top of the measuring tube is 0.5-1 m, connecting a second section of steel rod to the first section of steel rod, and continuously lowering the optical fiber along with the second section of steel rod;

step 406, repeating the step 405 for multiple times, connecting a J +1 section of steel rod to the J section of steel rod when the top of the J section of steel rod is lowered to a position away from the top of the measuring tube by a distance of 0.5-1 m, and continuously lowering the optical fiber along with the J +1 section of steel rod; wherein J is a positive integer;

step 407, until the optical fiber implantation plug contacts the optical fiber positioner, connecting the two extending ends of the optical fiber with a light-transmitting pen through an optical fiber jumper, judging that the optical fiber is normal, and adjusting the optical fiber implantation plug to be inserted into the optical fiber positioner;

step 408, sleeving a loose sleeve on the position, close to the top of the cast-in-place pile, of the optical fiber; wherein, two ends of the loose tube are sealed by waterproof adhesive tapes;

step 409, tensioning and screwing the multiple sections of steel rods to separate the first section of steel rods from the upper threaded joint, and pulling out the multiple sections of steel rods from the measuring pipe;

step 4010, repeating steps 401 to 409 to complete the layout of the optical fibers in the other measuring tube;

step five, grouting:

step 501, straightening an optical fiber and installing the optical fiber on a support above a measuring tube;

502, grouting through a grouting pipe by using a grouting pump until cement slurry overflows from the measuring pipe, and stopping grouting;

step six, pile head lead and initial value collection of the cast-in-place pile:

step 601, breaking a pile head at the position of 0.5-1 m of the top of the cast-in-place pile, arranging two extending ends of an optical fiber into an arc-shaped steel sleeve, leading out the optical fiber from the pile side of the cast-in-place pile, and connecting the optical fiber with an optical fiber demodulator; then pouring the pile head of the cast-in-place pile again;

step 602, in the process of not applying load to the cast-in-place pile, multiple groups of strain value initial values detected by an optical fiber demodulator are sent to a data processor; wherein, the data processor records the ith group strain value initial value as the ith pile body depth z_iCorresponding first strain initial value

Depth z of ith pile body_iCorresponding second strain initial value

Depth z of ith pile body_iCorresponding third strain initial value

And ith shaft depth z_iCorresponding fourth strain initial value

Wherein i is a positive integer, i is more than or equal to 1 and less than or equal to m, m is a positive integer not less than 6, and m represents the total number of the depth strain values of the pile body;

seventhly, load loading and strain data acquisition and processing of the cast-in-place pile:

701, operating a load loading mechanism to apply load to the cast-in-place pile, and detecting strain values corresponding to the depths of all pile bodies through an optical fiber demodulator;

step 702, repeating step 701 for multiple times, and applying multiple loads to the cast-in-place pile to obtain strain values corresponding to the depths of pile bodies when the loads are applied;

703, in the process of applying the jth load to the cast-in-place pile, sending multiple groups of strain values detected by the optical fiber demodulator to data processingA machine; recording the ith group strain value in the jth load loading as the ith pile body depth z in the jth load loading by the data processor_iCorresponding first strain value

Depth z of ith pile body during jth load loading_iCorresponding second strain value

Depth z of ith pile body during jth load loading_iCorresponding third strain value

And ith shaft depth z at jth load loading_iCorresponding fourth strain value

J is a natural number, j is more than or equal to 1 and less than or equal to p, p represents the total number of times of load loading, and p is a natural number more than 1;

step 704, using the data processor according to a formula

Obtaining the ith pile body depth z when the jth applied load is applied_iMeasured average value of strain of

Step 705, establishing a depth strain value fitting polynomial by using the data processor

Wherein, a_kRepresenting a monomial coefficient when the degree of a monomial in the fitting polynomial of the depth strain value is K, wherein z represents the depth independent variable of the pile body, and (z) represents the fitting strain, K and K are positive integers, K is more than or equal to 0 and less than or equal to K, and K represents the highest degree of the fitting polynomial;

step 706, respectively taking the m pile depths in the jth applied load as the independent variable of the pile depth by adopting the data processor, and establishing an independent variable pile depth matrix

707, respectively taking the m measured strain average values corresponding to the m pile depths during the jth applied load as measured strain values by using the data processor, and establishing a measured strain value matrix

Recording the coefficients of each monomial expression in the depth strain value fitting polynomial as a coefficient matrix A ═ a₀a₁a₂… a_k… a_K]^T；

Step 708, setting the length of the cast-in-place pile to be L, and setting the ith pile body depth z during the jth load loading by adopting the data processor_iAt the position of

Recording the depth of the middle or any two pile bodies as the depth constraint value of the first pile body

And second shaft depth constraint value

And the depth constraint value of the first pile body

Has an average value of measured strain of

Second pile depth constraint value

Has an average value of measured strain of

709, establishing a depth strain value fitting model by using the data processor, as follows:

wherein (A) is a fitting strain value objective function, min represents the minimum value, s.t. represents the constraint condition, | · |. Y₂A 2-norm representing a matrix; i | · | purple wind²Which is expressed as a square of the square of,

representing the first derivative of the independent variable of the pile body depth;

step 7010, solving the equation by using the data processor by using a least square method to obtain a coefficient matrix a ═ a₀a₁a₂… a_k… a_K]^TTo obtain a depth strain value fitting polynomial

Step 7011, the data processor is adopted to determine the ith pile depth z during the jth applied load_iSubstituting the depth strain value fitting polynomial to obtain the ith pile body depth z in the jth applied load_iThe strain fit at the cross section was taken and recorded

Step eight, acquiring internal force of the cast-in-place pile:

step 801, using the data processor according to a formula

Obtaining the ith pile body depth z_iAxial force Q at the cross section_i(ii) a Wherein E is_iIndicating the ith shaft depth z_iModulus of elasticity, A, of pile body concrete at cross section_iIndicating the ith shaft depth z_iThe cross section area of the pile body at the cross section;

step 802, processing with the numberAccording to the formula

Obtaining the ith pile body depth z_iThe depth z of the i +1 th pile body at the section_i+1Lateral resistance q at the cross section_is(ii) a Wherein u represents the perimeter of the pile body of the cast-in-place pile, and l_iIndicating the ith shaft depth z_iThe depth z of the i +1 th pile body at the section_i+1Pile length at cross section, Q_i+1Represents the (i + 1) th pile depth z_i+1Axial force at the cross section.

The above method is characterized in that: the length L of the cast-in-place pile in the step 708 is in a range of 60 m-66 m;

in the step 101, the outer diameter of the shunt ring is the same as the inner diameter of a reinforcement cage required by the cast-in-place pile, and the shunt ring is of a hollow structure;

in step 103, the first measuring pipe joint and the first positioning joint are positioned on the same straight line and are communicated with the splitter ring, the second measuring pipe joint and the second positioning joint are positioned on the same straight line and are communicated with the splitter ring, and the grouting joint is communicated with the splitter ring.

The above method is characterized in that: in step 201, the process of installing the pipe measuring section and the grouting pipe section in the multiple sections of reinforcement cages respectively is the same, and the specific process of installing the pipe measuring section and the grouting pipe section in any section of reinforcement cage respectively is as follows:

step 2011, binding a plurality of sections of reinforcement cages;

step 2012, connecting the plurality of measuring pipe sections in sequence into a measuring pipe section; the two adjacent pipe sections are bonded by using universal glue, and a waterproof adhesive tape is arranged outside the joint of the two adjacent pipe sections; wherein, the length of one pipe measuring section is the same as that of one section of the reinforcement cage;

step 2013, connecting a plurality of grouting pipe sections into a grouting pipe section in sequence; the two adjacent grouting pipe sections are connected by a grouting joint; wherein, the length of one grouting pipe section is the same as that of one section of reinforcement cage;

step 2014, respectively installing a pipe measuring section and a grouting pipe section in the multi-section reinforcement cage; the number of the measuring pipe sections is two, the two measuring pipe sections are symmetrically arranged on two sides of the grouting pipe section, an upper measuring pipe joint is arranged at the upper end of each measuring pipe section, and an upper grouting pipe joint is arranged at the upper end of each grouting pipe section.

The above method is characterized in that: in step 701, before applying a load to the cast-in-place pile, a load loading mechanism needs to be set, which includes the following steps:

step A, arranging a pile cap above a cast-in-place pile;

b, arranging anchor piles on the left side and the right side of the cast-in-place pile, and erecting a cross beam on the two anchor piles;

step C, arranging a middle beam at the bottom of the cross beam, and arranging a plurality of jacks between the pile caps and the middle beam;

in step 701, the load loading mechanism is operated to apply load to the cast-in-place pile, and the specific process is as follows: operating the jacks to extend, and applying load to the cast-in-place pile through pile caps by the combined force of the jacks; wherein, the loading counter force of jack is transmitted to the anchor pile through centre sill and crossbeam.

The above method is characterized in that: in step 302, the survey pipe and the grouting pipe are hoisted into a bored concrete pile drill hole along with a steel reinforcement cage, and the concrete process is as follows:

step 3021, hoisting the shunt ring and the optical fiber positioner to a bored pile drill hole along with a section of reinforcement cage, and marking the reinforcement cage hoisted for the first time as a first section of reinforcement cage;

when the top of the first section of reinforcement cage is 0.5-1 m higher than the top surface of the bored hole of the cast-in-place pile, hoisting the section of reinforcement cage provided with the pipe section to be measured and the grouting pipe section to the top of the first section of reinforcement cage, and completing hoisting of the second section of reinforcement cage;

step 3022, welding the bottom of the second section of reinforcement cage and the top of the first section of reinforcement cage;

step 3023, filling clear water into the measuring pipe section in the first section of the reinforcement cage;

step 3024, connecting a measured pipe section in the second section of the reinforcement cage with an upper measured pipe joint of a measured pipe section in the first section of the reinforcement cage, and connecting a grouting pipe section in the second section of the reinforcement cage with an upper grouting pipe joint at the upper part of a grouting pipe in the first section of the reinforcement cage;

step 3025, binding stirrups at the joint of the second section of reinforcement cage and the first section of reinforcement cage;

step 3026, continuously hoisting the second section of reinforcement cage down to the bored pile hole;

step 3027, according to the method in the steps 3022 to 3026, when the top of the section I of the reinforcement cage is 0.5m to 1m higher than the top surface of the bored hole of the cast-in-place pile, hoisting and welding the section I +1 of the reinforcement cage and connecting the pipe section to the grouting pipe; wherein I is a positive integer;

and 3028, repeating the step 3027 for multiple times, and completing the installation of the multiple sections of the reinforcement cages, the pipe measurement sections and the grouting pipe sections to obtain the installed pipe measurement and grouting pipes.

Compared with the prior art, the invention has the following advantages:

1. the shunting ring part, the optical fiber implanting plug and the optical fiber positioner are simple in structure, reasonable in design, simple and convenient to install and construct and low in investment cost.

2. The optical fiber implanter adopted by the invention can implant the optical fiber after the cast-in-place pile is formed, thereby avoiding the cross influence of the stage of hoisting the reinforcement cage and the optical fiber construction, being capable of completing the implantation of the optical fiber and being convenient to use.

3. The optical fiber implanting tube is implanted with optical fiber after the construction of the cast-in-place pile is completed, so that the cross influence of the construction of the cast-in-place pile is avoided, and the construction is convenient.

4. The cement paste is filled between the adopted optical fiber and the cast-in-place pile, and the pile body deformation of the cast-in-place pile can be well transmitted to the optical fiber through the solidification of the cement paste, so that the aim of testing the internal force of the pile body is fulfilled.

5. The adopted splitter ring is provided with the lower joint and the upper joint, the upper joint is used for installing the measuring pipe and the grouting pipe, the lower joint is used for installing the optical fiber implanting device, the structure is simple, the design is flexible, the measuring line number can be flexibly arranged according to needs, and later-stage grouting is facilitated.

6. The adopted optical fiber is arranged in the measuring tube, thereby avoiding the damage to the optical fiber in the processes of hoisting the steel reinforcement cage and pouring concrete and improving the survival rate.

7. The method for testing the internal force of the cast-in-place pile by using the optical fiber has the advantages of simple steps, convenient realization and simple and convenient construction.

8. The method for testing the internal force of the cast-in-place pile by using the optical fiber is simple and convenient to operate and good in using effect, firstly, the shunt ring part is manufactured, and secondly, the installation of the measuring tube, the grouting tube and the shunt ring part and the hoisting of the measuring tube, the grouting tube and the shunt ring part are carried out; then, the optical fiber is implanted into the test tube and is grouted, so that the optical fiber and the pile body are deformed cooperatively, and the internal force of the pile foundation is tested; and finally, acquiring the internal force of the cast-in-place pile, so that the test is convenient and simple, the accuracy of acquiring the internal force of the cast-in-place pile is improved, the cast-in-place pile construction is effectively adapted, and the continuous and smooth side resistance curve is ensured.

9. According to the invention, the constraint polynomial fitting is carried out on the test strain value data, so that the influence of test errors and uneven pile body material is reduced, and the reliability of the side resistance analysis result is improved.

10. The optical fiber implanting plug is matched with the optical fiber positioner, the plug in the optical fiber implanting plug is fixed through the telescopic tooth structure in the optical fiber positioner, the optical fiber does not float upwards along with slurry during grouting of the measuring tube, and the optical fiber is arranged along the whole length of the pile body of the cast-in-place pile.

In conclusion, the invention has reasonable design, is convenient for optical fiber implantation, has small influence on the construction of the cast-in-place pile and ensures the accuracy of the internal force test of the cast-in-place pile.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural diagram of the apparatus for testing internal force of a cast-in-place pile using an optical fiber according to the present invention.

Fig. 2 is a schematic structural diagram of a splitter ring part of the device for testing the internal force of a cast-in-place pile by using optical fibers.

FIG. 3 is a schematic structural diagram of an optical fiber positioner of the apparatus for testing the internal force of a cast-in-place pile by using an optical fiber according to the present invention.

FIG. 4 is a schematic structural diagram of an optical fiber implanting plug for testing the internal force of a cast-in-place pile by using an optical fiber according to the present invention.

Fig. 5 is a flow chart of the method for testing the internal force of the cast-in-place pile by using the optical fiber according to the present invention.

Description of reference numerals:

1-splitter ring component; 1-a shunt ring; 1-2 — a first alignment tab;

1-3-a second alignment tab; 1-4-a first test tube joint; 1-5-grouting connector;

1-6-second test tube joint; 2-measuring the tube; 3-grouting pipe;

4-an optical fiber; 5, loosening the sleeve; 6-upper measuring pipe joint;

7, arc steel sleeve; 8, drilling a bored pile; 9-filling piles;

10, anchoring piles; 11-pile cap; 12-fiber demodulation instrument;

13-upper grouting pipe joint; 14-a jack; 15-a cross beam;

16-a center beam; 17-an optical fiber positioner; 18-optical fiber implanting plug;

19-a reinforcement cage; 20-upper joint part; 21-a positioning body;

22-a second telescopic tooth member; 22-1 — a first tooth portion;

22-2 — second tooth portion; 22-3-third tooth portion; 22-4-vertical;

23-vertical channels; 24-a first telescoping tooth member; 25-installation cavity;

27-a spring; 28-guide pillars; 29-a transition;

30-upper thread joint; 31-plug block body; 32-a plug;

33-positioning grooves; 34-a U-shaped slot; 35-steel pipe.

Detailed Description

The device for testing the internal force of the cast-in-place pile by using the optical fiber as shown in fig. 1 to 4 comprises a splitter ring component 1 arranged in a cast-in-place pile 9, a measuring tube 2 and a grouting tube 3 mounted on the splitter ring component 1, an optical fiber structure arranged in the measuring tube 2, and an optical fiber positioner 17 arranged at the bottom of the splitter ring component 1, wherein the optical fiber structure comprises an optical fiber implanting plug 18 and an optical fiber 4 which is arranged on the optical fiber implanting plug 18 in a penetrating way and is arranged along the measuring tube 2, and the optical fiber implanting plug 18 extends into the optical fiber positioner 17;

the shunt ring component comprises a shunt ring 1-1, an upper joint arranged at the top of the shunt ring 1-1 and a lower joint arranged at the bottom of the shunt ring 1-1, the number of the upper joints is multiple, the upper joints are respectively connected with the measuring tube 2 and the grouting tube 3, the lower joint is connected with the optical fiber positioner 17, the measuring tube 2 comprises a plurality of connected measuring tube sections, two adjacent measuring tube sections are connected through an upper measuring tube joint 6, the grouting pipe 3 comprises a plurality of connected grouting pipe sections, two adjacent grouting pipe sections are connected through an upper grouting pipe joint 13, the optical fiber implanting plug 18 includes a plug block 31, an upper screw 30 mounted on the plug block 31 and a plug 32 mounted on the bottom of the plug block 31, the plug block body 31 is provided with a U-shaped groove 34 for the optical fiber 4 to penetrate through, and the optical fiber 4 is arranged in the measuring tube 2 in a U shape;

optical fiber locator 17 includes last joint portion 20 and the location body 21 of being connected with last joint portion 20, be provided with in the location body 21 and supply optical fiber to implant plug 18 male vertical passageway 23 and right the plug 32 carries out the flexible tooth structure of fixing a position, go up joint portion 20 with the lower clutch is connected, be provided with on the plug 32 with flexible tooth structure complex constant head tank 33, survey the intussuseption of pipe 2 and pack grout.

In this embodiment, the outer diameter of the shunt ring 1-1 is the same as the inner diameter of a reinforcement cage 19 required by a cast-in-place pile, and the shunt ring 1-1 is of a hollow structure;

the number of the upper joints is three, the three upper joints are uniformly distributed along the half circumference of the shunt ring 1-1, the three upper joints are respectively a first measuring pipe joint 1-4, a second measuring pipe joint 1-6 and a grouting connector 1-5, the number of the lower joints is two, the two lower joints are symmetrically distributed about the center of the shunt ring 1-1, and the two lower joints are respectively a first positioning joint 1-2 and a second positioning joint 1-3;

the grouting device comprises a first measuring pipe joint 1-4, a first positioning joint 1-2, a second measuring pipe joint 1-6, a second positioning joint 1-3, a diversion ring 1-1, a grouting connector 1-5 and a diversion ring 1-1, wherein the first measuring pipe joint 1-4 and the first positioning joint 1-2 are located on the same straight line, the first measuring pipe joint 1-4 and the first positioning joint 1-2 are communicated with the diversion ring 1-1, the second measuring pipe joint 1-6 and the second positioning joint 1-3 are communicated with the diversion ring 1-1, and the grouting connector 1-5 is communicated with the diversion ring 1-1.

In this embodiment, a transition portion 29 is disposed at the top of the positioning body 21 close to the upper joint portion 20, the cross section of the transition portion 29 gradually decreases from the upper joint portion 20 to the vertical channel 23, and the upper joint portion 20 is in threaded connection with the lower joint;

the telescopic tooth structure comprises a first telescopic tooth component 24 and a second telescopic tooth component 22 which are symmetrically arranged in the positioning body 21 and extend into the vertical channel 23, the first telescopic tooth component 24 and the second telescopic tooth component 22 are identical in structure, the first telescopic tooth component 24 and the second telescopic tooth component 22 respectively comprise a vertical portion 22-4, a plurality of tooth portions arranged along the height direction of the vertical portion 22-4, and a spring component connected between the vertical portion 22-4 and the positioning body 21.

In this embodiment, an installation cavity 25 for installing the spring component is provided in the positioning body 21, the number of the spring components is two, the two spring components are uniformly distributed along the height direction of the vertical portion 22-4, each of the two spring components includes a guide pillar 28 arranged on the positioning body 21 and a spring 27 sleeved on the guide pillar 28 and connected with the vertical portion 22-4, and one end of the spring 27 far away from the vertical portion 22-4 is fixedly connected with the positioning body 21;

the number of the tooth parts is three, the three tooth parts are respectively a first tooth part 22-1, a second tooth part 22-2 and a third tooth part 22-3, end faces, far away from the vertical part 22-4, of the first tooth part 22-1, the second tooth part 22-2 and the third tooth part 22-3 are conical surfaces, the lengths of the lower parts of the first tooth part 22-1, the second tooth part 22-2 and the third tooth part 22-3 are respectively larger than those of the upper parts of the first tooth part 22-1, the second tooth part 22-2 and the third tooth part 22-3, and a frustum cavity for inserting the positioning groove 33 in the plug 32 is formed between the two first tooth parts 22-1 and between the two second tooth parts 22-2 and between the two third tooth parts 22-3.

In this embodiment, the number of the positioning grooves 33 is plural, and plural positioning grooves 33 are arranged along the height direction of the plug 32, the depth of the positioning grooves 33 is gradually increased from top to bottom, and the U-shaped groove 34 extends to the central position of the plug block 31 along the width direction.

The upper threaded joint 30 is connected with a multi-section steel rod 35 in a threaded mode.

A method for testing the internal force of a cast-in-place pile using an optical fiber as shown in fig. 5 comprises the following steps:

step one, manufacturing a shunt ring component:

step 101, manufacturing a shunt ring 1-1;

102, welding a lower joint at the bottom of the shunt ring 1-1; the number of the lower joints is two, the two lower joints are symmetrically arranged relative to the center of the shunt ring 1-1, and the two lower joints are respectively marked as a first positioning joint 1-2 and a second positioning joint 1-3;

103, welding an upper connector on the top of the shunt ring 1-1 to finish the manufacturing of the shunt ring component 1; the number of the upper joints is three, the three upper joints are uniformly distributed along the half circumference of the shunt ring 1-1, and the three upper joints are respectively marked as a first pipe measuring joint 1-4, a second pipe measuring joint 1-6 and a grouting connector 1-5;

step 202, installing a shunt ring 1-1 at the bottom of a section of reinforcement cage, installing pipe measuring sections on a first pipe measuring joint 1-4 and a second pipe measuring joint 1-6, installing a grouting pipe section on a grouting connector 1-5, installing a pipe measuring joint 6 at the upper end of the pipe measuring section, and installing a grouting pipe joint 13 at the upper end of the grouting pipe section; wherein the outer side wall of the shunt ring 1-1 is welded with the inner side wall of a section of reinforcement cage;

step 203, respectively installing optical fiber positioners 17 on a first positioning connector 1-2 and a second positioning connector 1-3 at the bottom of the shunt ring 1-1; wherein, the distance between the bottom of the optical fiber positioner 17 and the bottom of a section of reinforcement cage is 1 m-2 m;

step three, hoisting the shunt ring, the measuring pipe and the grouting pipe:

step 301, hoisting the shunt ring 1-1 and the optical fiber positioner 17 to a bored concrete pile drill hole 8 along with a section of reinforcement cage;

step 302, hoisting the pipe measuring section and the grouting pipe section to the bored concrete pile drill hole 8 along with the reinforcement cage, and completing installation of the pipe measuring 2 and the grouting pipe 3;

step 303, pouring concrete into the bored pile bore 8 to form a bored pile 9; wherein, the measuring pipe 2 and the grouting pipe 3 extend out of the cast-in-place pile 9;

step four, implanting optical fibers:

step 401, forming a U-shaped groove 34 on the optical fiber implanting plug 18;

step 402, threading the optical fiber 4 into the U-shaped groove 34, and fixing with glue; a light-transmitting pen is connected with two extending ends of the optical fiber 4 through an optical fiber jumper wire, and the optical fiber 4 is judged to be normal; wherein, two ends of the optical fiber respectively extend out of the U-shaped groove 34;

step 403, connecting a section of steel rod to the upper threaded connector 30 on the optical fiber implanting plug 18;

404, putting the optical fiber 4 down into the measuring tube 2 along with the first section of steel rod and the optical fiber implanting plug 18;

step 405, when the top of the first section of steel rod is lowered to the position where the distance between the top of the measuring tube 2 and the top of the measuring tube is 0.5-1 m, connecting a second section of steel rod to the first section of steel rod, and continuously lowering the optical fiber 4 along with the second section of steel rod;

step 406, repeating the step 405 for multiple times, connecting a J +1 section of steel rod to the J section of steel rod when the top of the J section of steel rod is lowered to a position which is 0.5-1 m away from the top of the measuring tube 2, and continuously lowering the optical fiber 4 along with the J +1 section of steel rod; wherein J is a positive integer;

step 407, until the optical fiber implanting plug 18 contacts the optical fiber positioner 17, connecting the two extending ends of the optical fiber 4 by using a light-transmitting pen through an optical fiber jumper, judging that the optical fiber 4 is normal, and adjusting the optical fiber implanting plug 18 to be inserted into the optical fiber positioner 17;

step 408, sleeving a loose sleeve 5 on the position, close to the top of the cast-in-place pile 9, of the optical fiber 4; wherein, two ends of the loose tube 5 are sealed by waterproof adhesive tapes;

step 409, tensioning and screwing the multiple sections of steel rods to separate the first section of steel rods from the upper threaded joint 30, and pulling the multiple sections of steel rods out of the measuring pipe 2;

step 4010, repeating steps 401 to 409, and completing the layout of the optical fiber 4 in the other measuring tube 2;

step five, grouting:

step 501, straightening the optical fiber 4 and installing the optical fiber on a bracket above the measuring tube 2;

502, grouting through a grouting pipe 3 by using a grouting pump until cement slurry overflows from a measuring pipe 2, and stopping grouting;

step 601, breaking a pile head at the position of 0.5-1 m of the top of the cast-in-place pile 9, arranging two extending ends of an optical fiber 4 into an arc-shaped steel sleeve 7, leading out from the pile side of the cast-in-place pile, and connecting the optical fiber 4 with an optical fiber demodulator 12; then pouring the pile head of the cast-in-place pile 9 again;

step 602, in the process of not applying load to the cast-in-place pile 9, multiple groups of strain value initial values detected by the optical fiber demodulator 12 are sent to the data processor; wherein, the data processor records the ith group strain value initial value as the ith pile body depth z_iCorresponding first strain initial value

Depth z of ith pile body_iCorresponding second strain initial value

Depth z of ith pile body_iCorresponding third strain initial value

And ith shaft depth z_iCorresponding fourth strain initial value

701, operating a load loading mechanism to apply load to the cast-in-place pile 9, and detecting strain values corresponding to the depths of all pile bodies through an optical fiber demodulator 12;

step 702, repeating step 701 for multiple times, and applying multiple loads to the cast-in-place pile 9 to obtain strain values corresponding to the depths of pile bodies when the loads are applied;

703, in the process of applying the jth load to the cast-in-place pile 9, sending multiple groups of strain values detected by the optical fiber demodulator 12 to the data processor; recording the ith group strain value in the jth load loading as the ith pile body depth z in the jth load loading by the data processor_iCorresponding first strain value

And ith shaft depth z at jth load loading_iCorresponding fourth strain value

step 704, using the data processor according to a formula

Step 708, setting the length of the cast-in-place pile 9 to be L, and setting the ith pile body depth z during the jth load loading by adopting the data processor_iAt the position of

And second shaft depth constraint value

And the depth constraint value of the first pile body

Has an average value of measured strain of

Second pile depth constraint value

Has an average value of measured strain of

step 7010, the data processor is used to solve the formula one by using a least square method to obtain a coefficient matrix a ═ a₀a₁a₂… a_k… a_K]^TTo obtain a depth strain value fitting polynomial

Step 7011, using said data processor to process the firstDepth z of ith pile body under j times of applied load_iFitting polynomial by substituting depth strain value

Obtaining the ith pile body depth z when the jth applied load is applied_iThe strain fit at the cross section was taken and recorded

Step eight, acquiring internal force of the cast-in-place pile:

step 801, using the data processor according to a formula

step 802, using the number processor according to a formula

Obtaining the ith pile body depth z_iThe depth z of the i +1 th pile body at the section_i+1Lateral resistance q at the cross section_is(ii) a Wherein u represents the perimeter of the shaft of the bored concrete pile 9, and l_iIndicating the ith shaft depth z_iThe depth z of the i +1 th pile body at the section_i+1Pile length at cross section, Q_i+1Represents the (i + 1) th pile depth z_i+1Axial force at the cross section.

In this embodiment, the length L of the cast-in-place pile 9 in step 708 is in the range of 60m to 66 m;

in the step 101, the outer diameter of the shunt ring 1-1 is the same as the inner diameter of a reinforcement cage required by a cast-in-place pile, and the shunt ring 1-1 is of a hollow structure;

in step 103, the first measuring pipe joint 1-4 and the first positioning joint 1-2 are located on the same straight line, the first measuring pipe joint 1-4 and the first positioning joint 1-2 are communicated with the shunt ring 1-1, the second measuring pipe joint 1-6 and the second positioning joint 1-3 are located on the same straight line, the second measuring pipe joint 1-6 and the second positioning joint 1-3 are communicated with the shunt ring 1-1, and the grouting joint 1-5 is communicated with the shunt ring 1-1.

In this embodiment, in step 201, the processes of installing the pipe measurement section and the grouting pipe section in the multiple sections of the reinforcement cages are the same, and the specific processes of installing the pipe measurement section and the grouting pipe section in any section of the reinforcement cage are as follows:

step 2011, binding a plurality of sections of reinforcement cages;

step 2014, respectively installing a pipe measuring section and a grouting pipe section in the multi-section reinforcement cage; the number of the measuring pipe sections is two, the two measuring pipe sections are symmetrically arranged on two sides of the grouting pipe section, an upper measuring pipe joint 6 is installed at the upper end of each measuring pipe section, and an upper grouting pipe joint 13 is installed at the upper end of each grouting pipe section.

In this embodiment, before applying a load to cast-in-place pile 9 in step 701, a load loading mechanism needs to be set, which includes the following steps:

step A, arranging a pile cap 11 above a cast-in-place pile 9;

b, arranging anchor piles 10 on the left side and the right side of the cast-in-place pile 9, and erecting cross beams 15 on the two anchor piles 10;

step C, arranging a middle beam 16 at the bottom of the cross beam 15, and arranging a plurality of jacks 14 between the pile caps 11 and the middle beam 16;

in step 701, the load loading mechanism is operated to apply a load to the cast-in-place pile 9, and the specific process is as follows: operating the jacks 14 to extend, and applying load to the cast-in-place pile 9 through the pile cap 11 by the combined force of the jacks 14; wherein the loading counter force of the jack 14 is transmitted to the anchor pile 10 through the intermediate beam 16 and the cross beam 15.

In this embodiment, in step 302, the survey pipe and the grouting pipe are hoisted into the bored concrete pile bore hole along with the steel reinforcement cage, and the specific process is as follows:

step 3021, hoisting the shunt ring 1-1 and the optical fiber positioner 17 to a bored concrete pile drill hole 8 along with a section of reinforcement cage, and marking the reinforcement cage hoisted for the first time as a first section of reinforcement cage;

when the top of the first section of reinforcement cage is 0.5-1 m higher than the top surface of a bored pile 8, hoisting the section of reinforcement cage provided with the pipe section to be measured and the grouting pipe section to the top of the first section of reinforcement cage, and completing hoisting of the second section of reinforcement cage;

step 3024, connecting a measured pipe section in the second section of the reinforcement cage with an upper measured pipe joint 6 of a measured pipe section in the first section of the reinforcement cage, and connecting a grouting pipe section in the second section of the reinforcement cage with an upper grouting pipe joint 13 at the upper part of a grouting pipe in the first section of the reinforcement cage;

step 3026, continuously hoisting the second section of reinforcement cage down to the bored pile drill hole 8;

step 3027, according to the method in the steps 3022 to 3026, when the top of the section I of the reinforcement cage is 0.5m to 1m higher than the top surface of the bored pile hole 8, hoisting and welding the section I +1 of the reinforcement cage and connecting the pipe section to the grouting pipe; wherein I is a positive integer;

and 3028, repeating the step 3027 for multiple times, and completing the installation of the multiple sections of reinforcement cages, the pipe measurement sections and the grouting pipe sections to obtain the installed pipe measurement 2 and grouting pipe 3.

In this embodiment, it should be noted that the optical fiber 4 in the measuring tube 2 is arranged in a U shape, and the optical fiber 4 includes a first optical fiber portion, a second optical fiber portion, and a U-shaped connecting portion connecting bottoms of the first optical fiber portion and the second optical fiber portion.

In this embodiment, it should be noted that the ith pile depth z_iCorresponding first strain initial value

And ith shaft depth z at jth load loading_iCorresponding first strain value

Corresponding to the strain data detected by the first optical fiber part in one measuring tube 2, i-th pile body depth z_iCorresponding second strain initial value

And ith shaft depth z at jth load loading_iCorresponding second strain value

I pile depths z corresponding to strain data detected by the second optical fiber part in one measuring tube 2_iCorresponding third strain initial value

And ith shaft depth z at jth load loading_iCorresponding third strain value

Corresponding to the strain data detected by the first optical fiber part in the other measuring tube 2, i-th pile body depth z_iCorresponding fourth strain initial value

And ith shaft depth z at jth load loading_iCorresponding fourth strain value

Corresponding to the strain data detected by the second fibre portion in the other tube 2.

In this embodiment, it should be noted that the pile body depth refers to the distance between the pile body and the top of the cast-in-place pile 9.

In this embodiment, the cast-in-place pile 9 is from top to bottom z₁Indicating the 1 st shaft depth, z₂Indicating the 2 nd shaft depth, z_mIndicating the m-th shaft depth, z_i+1The (i + 1) th shaft depth is shown.

In this embodiment, the (i + 1) th pile depth z_i+1And ith shaft depth z_iThe pile length between the two piles is 20 cm-50 cm.

In the present embodiment, the first and second electrodes are,

indicating the 1 st shaft depth z₁The average value of the measured strain;

indicating the 2 nd shaft depth z₂The average value of the measured strain;

indicating the m-th shaft depth z_mAverage of the measured strain at (a).

In this embodiment, it should be noted that the fiber demodulation instrument 12 can refer to the fTB2505 fiber demodulation instrument of BOFDA.

In this embodiment, the data processor is a computer.

In this embodiment, the upper joint part 20 is screwed with the first and second alignment joints 1-2 and 1-3.

In the embodiment, the value range of the maximum degree K of the fitting polynomial is 4-6.

In this embodiment, the length of the cast-in-place pile 9 is 60m, and the average diameter of the cast-in-place pile 9 is 0.946 m.

In this embodiment, it should be noted that, in the actual use process, the first pile depth constraint value

Is 53m, and the depth of the second pile body is restricted

Is 58 m.

In conclusion, the optical fiber implanting plug and the optical fiber positioner are matched, the plug in the optical fiber implanting plug is fixed through the telescopic tooth structure in the optical fiber positioner, the optical fiber is ensured not to float up along with slurry during grouting of a measuring tube, the optical fiber is arranged along the length of the pile body of the cast-in-place pile, the design is reasonable, the optical fiber implanting is convenient, the influence on construction of the cast-in-place pile is small, the internal force test of the cast-in-place pile is ensured to be accurate, the influence of test errors and uneven pile body materials is reduced by carrying out constraint polynomial fitting on test strain value data, and the reliability of a side resistance analysis result is improved.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. The device for testing the internal force of the cast-in-place pile by using the optical fiber is characterized by comprising a splitter ring part (1) arranged in the cast-in-place pile (9), a measuring tube (2) and a grouting tube (3) which are installed on the splitter ring part (1), an optical fiber structure arranged in the measuring tube (2), and an optical fiber positioner (17) arranged at the bottom of the splitter ring part (1), wherein the optical fiber structure comprises an optical fiber implanting plug (18) and the optical fiber (4) which is arranged on the optical fiber implanting plug (18) in a penetrating manner and is arranged along the measuring tube (2), and the optical fiber implanting plug (18) extends into the optical fiber positioner (17);

the shunt ring part comprises a shunt ring (1-1), an upper joint arranged at the top of the shunt ring (1-1) and a lower joint arranged at the bottom of the shunt ring (1-1), the number of the upper joints is a plurality of, the upper joints are respectively connected with a measuring tube (2) and a grouting tube (3), the lower joint is connected with an optical fiber positioner (17), the measuring tube (2) comprises a plurality of connected measuring tube sections, two adjacent measuring tube sections are connected through an upper measuring tube joint (6), the grouting tube (3) comprises a plurality of connected grouting tube sections, two adjacent grouting tube sections are connected through an upper grouting tube joint (13), the optical fiber implanting plug (18) comprises a plug block body (31), an upper thread joint (30) arranged on the plug block body (31) and a plug (32) arranged at the bottom of the plug block body (31), the plug block body (31) is provided with a U-shaped groove (34) for the optical fiber (4) to penetrate through, and the optical fiber (4) is arranged in the measuring tube (2) in a U shape;

optical fiber locator (17) include top connection portion (20) and with top connection portion (20) be connected location body (21), it plants plug (18) male vertical passageway (23) and right to be provided with in location body (21) to supply the optical fiber the plug (32) carry out the flexible tooth structure of location, top connection portion (20) with the lower clutch is connected, be provided with on plug (32) with flexible tooth structure complex constant head tank (33), survey the intussuseption grout in pipe (2).

2. The apparatus for testing the internal force of a bored concrete pile using an optical fiber according to claim 1, wherein: the outer diameter of the shunt ring (1-1) is the same as the inner diameter of a reinforcement cage (19) required by a cast-in-place pile, and the shunt ring (1-1) is of a hollow structure;

the number of the upper joints is three, the three upper joints are uniformly distributed along the half circumference of the shunt ring (1-1), the number of the three upper joints is two, the three upper joints are respectively a first measuring pipe joint (1-4), a second measuring pipe joint (1-6) and a grouting connector (1-5), the two lower joints are symmetrically distributed about the center of the shunt ring (1-1), and the two lower joints are respectively a first positioning joint (1-2) and a second positioning joint (1-3);

the grouting device comprises a first measuring pipe joint (1-4), a first positioning joint (1-2), a second measuring pipe joint (1-6), a second positioning joint (1-3), a grouting connector (1-5) and a shunt ring (1-1), wherein the first measuring pipe joint (1-4) and the first positioning joint (1-2) are located on the same straight line, the first measuring pipe joint (1-4) and the first positioning joint (1-2) are communicated with the shunt ring (1-1), the second measuring pipe joint (1-6) and the second positioning joint (1-3) are communicated with the shunt ring (1-1).

3. The apparatus for testing the internal force of a bored concrete pile using an optical fiber according to claim 1, wherein: the top of the positioning body (21) close to the upper joint part (20) is provided with a transition part (29), the section of the transition part (29) is gradually reduced from the upper joint part (20) to the vertical channel (23), and the upper joint part (20) is in threaded connection with the lower joint;

the telescopic tooth structure comprises a first telescopic tooth component (24) and a second telescopic tooth component (22) which are symmetrically arranged in a positioning body (21) and extend into a vertical channel (23), the first telescopic tooth component (24) and the second telescopic tooth component (22) are identical in structure, the first telescopic tooth component (24) and the second telescopic tooth component (22) respectively comprise a vertical portion (22-4), a plurality of tooth portions arranged along the height direction of the vertical portion (22-4), and a spring component connected between the vertical portion (22-4) and the positioning body (21).

4. The apparatus for testing the internal force of a bored concrete pile using an optical fiber according to claim 3, wherein: the positioning body (21) is internally provided with an installation cavity (25) for installing the spring components, the number of the spring components is two, the two spring components are uniformly distributed along the height direction of the vertical part (22-4), each spring component comprises a guide post (28) arranged on the positioning body (21) and a spring (27) which is sleeved on the guide post (28) and connected with the vertical part (22-4), and one end, far away from the vertical part (22-4), of the spring (27) is fixedly connected with the positioning body (21);

the number of the tooth parts is three, the three tooth parts are respectively a first tooth part (22-1), a second tooth part (22-2) and a third tooth part (22-3), the end surfaces of the first tooth part (22-1), the second tooth part (22-2) and the third tooth part (22-3) far away from the vertical part (22-4) are conical surfaces, the length of the lower parts of the first tooth part (22-1), the second tooth part (22-2) and the third tooth part (22-3) is respectively greater than the length of the upper parts of the first tooth part (22-1), the second tooth part (22-2) and the third tooth part (22-3), and a frustum cavity for inserting a positioning groove (33) in the plug (32) is formed between the two first tooth parts (22-1) and between the two second tooth parts (22-2) and the two third tooth parts (22-3).

5. The apparatus for testing the internal force of a bored concrete pile using an optical fiber according to claim 1, wherein: the quantity of constant head tank (33) is a plurality of, and is a plurality of constant head tank (33) are laid along plug (32) direction of height, constant head tank (33) from top to bottom degree of depth increase gradually, U-shaped groove (34) extend to plug block (31) along width direction's central point.

The upper threaded joint (30) is in threaded connection with a multi-section steel rod (35).

6. A method for testing the internal force of a bored pile using the apparatus of claim 1, comprising the steps of:

step one, manufacturing a shunt ring component:

step 101, manufacturing a shunt ring (1-1);

102, welding a lower joint at the bottom of the shunt ring (1-1); the number of the lower joints is two, the two lower joints are symmetrically arranged relative to the center of the shunt ring (1-1), and the two lower joints are respectively marked as a first positioning joint (1-2) and a second positioning joint (1-3);

103, welding an upper joint on the top of the shunt ring (1-1) to complete the manufacture of the shunt ring component (1); the number of the upper joints is three, the three upper joints are uniformly distributed along the half circumference of the shunt ring (1-1), and the three upper joints are respectively marked as a first pipe measuring joint (1-4), a second pipe measuring joint (1-6) and a grouting connector (1-5);

202, installing a shunt ring (1-1) at the bottom of a section of steel reinforcement cage, installing pipe sections on a first pipe measuring joint (1-4) and a second pipe measuring joint (1-6), installing a grouting pipe section on a grouting connector (1-5), installing a pipe measuring joint (6) at the upper end of the pipe measuring section, and installing a grouting pipe joint (13) at the upper end of the grouting pipe section; wherein the outer side wall of the shunt ring (1-1) is welded with the inner side wall of a section of reinforcement cage;

step 203, respectively installing optical fiber positioners (17) on a first positioning connector (1-2) and a second positioning connector (1-3) at the bottom of the shunt ring (1-1); the distance between the bottom of the optical fiber positioner (17) and the bottom of a section of reinforcement cage is 1-2 m;

step three, hoisting the shunt ring, the measuring pipe and the grouting pipe:

step 301, hoisting the shunt ring (1-1) and the optical fiber positioner (17) into a bored concrete pile drill hole (8) along with a section of reinforcement cage;

step 302, hoisting the pipe measuring section and the grouting pipe section to a bored concrete pile drill hole (8) along with a reinforcement cage, and completing installation of the pipe measuring (2) and the grouting pipe (3);

step 303, pouring concrete into the bored pile bore (8) to form a bored pile (9); wherein the measuring pipe (2) and the grouting pipe (3) extend out of the cast-in-place pile (9);

step four, implanting optical fibers:

step 401, forming a U-shaped groove (34) on the optical fiber implanting plug (18);

step 402, threading an optical fiber (4) in the U-shaped groove (34), and fixing the optical fiber by glue; a light-transmitting pen is connected with two extending ends of the optical fiber (4) through an optical fiber jumper wire, and the optical fiber (4) is judged to be normal; wherein, two ends of the optical fiber respectively extend out of the U-shaped groove (34);

step 403, connecting a section of steel rod on an upper threaded connector (30) on the optical fiber implantation plug (18);

404, lowering the optical fiber (4) into the measuring tube (2) along with the first section of steel rod and the optical fiber implanting plug (18);

405, when the top of the first section of steel rod is lowered to a position which is 0.5-1 m away from the top of the measuring tube (2), connecting a second section of steel rod to the first section of steel rod, and continuously lowering the optical fiber (4) along with the second section of steel rod;

step 406, repeating the step 405 for multiple times, connecting a J +1 section of steel rod to the J section of steel rod when the top of the J section of steel rod is lowered to a position which is 0.5-1 m away from the top of the measuring tube (2), and continuously lowering the optical fiber (4) along with the J +1 section of steel rod; wherein J is a positive integer;

step 407, until the optical fiber implanting plug (18) contacts the optical fiber positioner (17), connecting the two extending ends of the optical fiber (4) through an optical fiber jumper by using a light-transmitting pen, judging that the optical fiber (4) is normal, and adjusting the optical fiber implanting plug (18) to be inserted into the optical fiber positioner (17);

step 408, sleeving a loose sleeve (5) on the part, close to the top of the cast-in-place pile (9), of the optical fiber (4); wherein, two ends of the loose tube (5) are sealed by waterproof adhesive tapes;

409, tensioning and screwing the multiple sections of steel rods to separate the first section of steel rods from the upper threaded joint (30), and pulling the multiple sections of steel rods out of the measuring pipe (2);

step 4010, repeating steps 401 to 409 to complete the layout of the optical fiber (4) in the other measuring tube (2);

step five, grouting:

step 501, straightening an optical fiber (4) and installing the optical fiber on a support above a measuring tube (2);

502, grouting through a grouting pipe (3) by using a grouting pump until cement slurry overflows from the measuring pipe (2), and stopping grouting;

601, breaking a pile head at the position of 0.5-1 m of the top of a cast-in-place pile (9), arranging two extending ends of an optical fiber (4) into an arc-shaped steel sleeve (7), leading out from the pile side of the cast-in-place pile, and connecting the optical fiber demodulation instrument (12); then pouring the pile head of the cast-in-place pile (9) again;

step 602, in the process of not applying load to the cast-in-place pile (9), multiple groups of strain value initial values detected by the optical fiber demodulator (12) are sent to a data processor; wherein, the data processor records the ith group strain value initial value as the ith pile body depth z_iCorresponding first strain initial value

Depth z of ith pile body_iCorresponding second strain initial value

Depth z of ith pile body_iCorresponding third strain initial value

And ith shaft depth z_iCorresponding fourth strain initial value

701, operating a load loading mechanism to apply load to the cast-in-place pile (9), and detecting strain values corresponding to the depths of all pile bodies through an optical fiber demodulator (12);

step 702, repeating step 701 for multiple times, and applying multiple loads to the cast-in-place pile (9) to obtain strain values corresponding to the depths of the pile bodies when the loads are applied;

703, in the process of applying the jth load to the cast-in-place pile (9), sending a plurality of groups of strain values detected by the optical fiber demodulator (12) to a data processor; recording the ith group strain value in the jth load loading as the ith pile body depth z in the jth load loading by the data processor_iCorresponding first strain value

And ith shaft depth z at jth load loading_iCorresponding fourth strain value

step 704, using the data processor according to a formula

Step 708, setting the length of the cast-in-place pile (9) to be L, and setting the ith pile body depth z during the jth load loading by adopting the data processor_iAt the position of

The depth of the middle or arbitrary two pile bodies is recorded as the depth of the first pile bodyValue of beam

And second shaft depth constraint value

And the depth constraint value of the first pile body

Has an average value of measured strain of

Second pile depth constraint value

Has an average value of measured strain of

step 7010, solving equation (one) by using the data processor by using a least square method to obtain a coefficient matrix a ═ a₀a₁a₂… a_k… a_K]^TTo obtain a depth strain value fitting polynomial

Step eight, acquiring internal force of the cast-in-place pile:

step 801, using the data processor according to a formula

step 802, using the number processor according to a formula

Obtaining the ith pile body depth z_iThe depth z of the i +1 th pile body at the section_i+1Lateral resistance q at the cross section_is(ii) a Wherein u represents the perimeter of the pile body of the cast-in-place pile (9), and l_iIndicating the ith shaft depth z_iThe depth z of the i +1 th pile body at the section_i+1Pile length at cross section, Q_i+1Represents the (i + 1) th pile depth z_i+1Axial force at the cross section.

7. The method of claim 6, wherein: the length L of the cast-in-place pile (9) in the step 708 is in the range of 60 m-66 m;

in the step 101, the outer diameter of the shunt ring (1-1) is the same as the inner diameter of a reinforcement cage required by a cast-in-place pile, and the shunt ring (1-1) is of a hollow structure;

in the step 103, the first measuring pipe joint (1-4) and the first positioning joint (1-2) are located on the same straight line, the first measuring pipe joint (1-4) and the first positioning joint (1-2) are communicated with the shunt ring (1-1), the second measuring pipe joint (1-6) and the second positioning joint (1-3) are located on the same straight line, the second measuring pipe joint (1-6) and the second positioning joint (1-3) are communicated with the shunt ring (1-1), and the grouting joint (1-5) is communicated with the shunt ring (1-1).

8. The method of claim 6, wherein: in step 201, the process of installing the pipe measuring section and the grouting pipe section in the multiple sections of reinforcement cages respectively is the same, and the specific process of installing the pipe measuring section and the grouting pipe section in any section of reinforcement cage respectively is as follows:

step 2011, binding a plurality of sections of reinforcement cages;

step 2014, respectively installing a pipe measuring section and a grouting pipe section in the multi-section reinforcement cage; the number of the measuring pipe sections is two, the two measuring pipe sections are symmetrically arranged on two sides of the grouting pipe section, an upper measuring pipe joint (6) is installed at the upper end of each measuring pipe section, and an upper grouting pipe joint (13) is installed at the upper end of each grouting pipe section.

9. The method of claim 6, wherein: in step 701, before applying a load to the cast-in-place pile (9), a load loading mechanism needs to be set, and the following steps are performed:

step A, arranging a pile cap (11) above a cast-in-place pile (9);

b, arranging anchor piles (10) on the left side and the right side of the cast-in-place pile (9), and erecting cross beams (15) on the two anchor piles (10);

step C, arranging a middle beam (16) at the bottom of the cross beam (15), and arranging a plurality of jacks (14) between the pile cap (11) and the middle beam (16);

in step 701, the load loading mechanism is operated to apply load to the cast-in-place pile (9), and the specific process is as follows: operating the jacks (14) to extend, and applying load to the cast-in-place pile (9) through the pile cap (11) by the combined force of the jacks (14); wherein the loading counter force of the jack (14) is transmitted to the anchor pile (10) through the middle beam (16) and the cross beam (15).

10. The method of claim 6, wherein: in step 302, the survey pipe and the grouting pipe are hoisted into a bored concrete pile drill hole along with a steel reinforcement cage, and the concrete process is as follows:

step 3021, hoisting the shunt ring (1-1) and the optical fiber positioner (17) to a bored concrete pile drill hole (8) along with a section of reinforcement cage, and marking the reinforcement cage hoisted for the first time as a first section of reinforcement cage;

when the top of the first section of reinforcement cage is 0.5-1 m higher than the top surface of a bored pile (8), hoisting the section of reinforcement cage provided with the pipe section to be measured and the grouting pipe section to the top of the first section of reinforcement cage, and completing hoisting of the second section of reinforcement cage;

step 3024, connecting a measured pipe section in the second section of the reinforcement cage with an upper measured pipe joint (6) of a measured pipe section in the first section of the reinforcement cage, and connecting a grouting pipe section in the second section of the reinforcement cage with an upper grouting pipe joint (13) at the upper part of a grouting pipe in the first section of the reinforcement cage;

step 3026, continuously hoisting the second section of reinforcement cage down to the bored pile bore (8);

step 3027, according to the method in the steps 3022 to 3026, when the top of the section I of the reinforcement cage is 0.5m to 1m higher than the top surface of the bored pile hole (8), hoisting and welding the section I +1 of the reinforcement cage and connecting the pipe section to be tested and the grouting pipe; wherein I is a positive integer;

and 3028, repeating the step 3027 for multiple times to complete the installation of the multiple sections of the reinforcement cage, the measurement pipe section and the grouting pipe section, so as to obtain the installed measurement pipe (2) and the installed grouting pipe (3).