CN104499512B - Foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof - Google Patents

Abstract

The present invention relates to a kind of foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof.The object of this invention is to provide a kind of foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof, to monitor the pile shaft force of foundation pile, horizontal force, moment of flexure, the value of moment of torsion and the regularity of distribution thereof.Technical scheme of the present invention is: a kind of foundation pile pile body three dimensional strain and force parameter monitoring system, and bury 9 sensor fibres underground along pile body surface, sensor fibre is divided into three groups, often organizes 3; First group of sensor fibre is axial optical fiber, and 3 sensor fibres are all axial arranged along pile body; Second group of sensor fibre is S type optical fiber, and 3 sensor fibres are around on pile body all counterclockwise, from pile body one end evenly around to the other end; 3rd group of sensor fibre is anti-S type optical fiber, and 3 sensor fibres are around on pile body all clockwise, from pile body one end evenly around to the other end.The present invention is applicable to rock and soil engineering detection, monitoring technical field.<!-- 2 -->

Description

Foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof

Technical field

The present invention relates to a kind of foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof, especially a kind of based on Distributed Optical Fiber Sensing Techniques foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof.Be applicable to rock and soil engineering detection, monitoring technical field.

Background technology

Many engineering structuress are built in complex environment, or structural system itself is very complicated, these complexity all likely cause in structure and act on the loads such as force and moment, as towering buildings such as offshore production platform, Offshore Bridges pile foundation, Large Transmission Tower, super high rise building and traffic signals towers, the load that these structures transmit is generally final to be born by a clump of piles and passes to ground.Existing foundation pile external loads monitoring concentrates on the test of pile shaft force mostly, seldom monitors the horizontal force and moment of pile body.

Along with the development of Fibre Optical Sensor demodulation techniques (Brillouin demodulation techniques BOTDA/BOTDR), sensor fibre can respond to strain again can signal transmission, forms distributed strain sensor.Based on the Distributed Optical Fiber Sensing Techniques of Brillouin scattering, there is the outstanding advantages such as good endurance, inferred-zero drift, not live line work, electromagnetism interference, transport tape be roomy, the distributed measurement to parameter to be measured can be realized, promote the use in fields such as building, water conservancy, electric power, traffic, petrochemical industry, oceans at present, but there is not yet based on the method and system that Distributed Optical Fiber Sensing Techniques monitoring foundation pile bears force and moment.

Summary of the invention

The technical problem to be solved in the present invention is: provide a kind of foundation pile pile body three dimensional strain and force parameter monitoring system and method for measurement thereof, to monitor the pile shaft force of foundation pile, horizontal force, moment of flexure, the value of moment of torsion and the regularity of distribution thereof.

The technical solution adopted in the present invention is: a kind of foundation pile pile body three dimensional strain and force parameter monitoring system, is characterized in that: bury 9 sensor fibres underground along pile body surface, sensor fibre is divided into three groups, often organizes 3;

First group of sensor fibre is axial optical fiber, and 3 sensor fibres are all axial arranged along pile body; Second group of sensor fibre is S type optical fiber, and 3 sensor fibres are around on pile body all counterclockwise, from pile body one end evenly around to the other end; 3rd group of sensor fibre is anti-S type optical fiber, and 3 sensor fibres are around on pile body all clockwise, from pile body one end evenly around to the other end;

Described axial optical fiber and S type optical fiber, anti-S type optical fiber all have some joinings, and with the joining of S type optical fiber with overlap with the joining one_to_one corresponding of anti-S type optical fiber and form test point on every root axial optical fiber, the edge of each test point place pile body cross section has three test points; The angle of described S type optical fiber, anti-S type optical fiber and axial optical fiber is θ, 0 ° of < θ <90;

9 sensor fibre formation from beginning to end, 1 optical fiber, the optical fiber two ends formed are connected with Brillouin's (FBG) demodulator.

3 axial optical fibers are evenly arranged in pile body surface, 3 S type optical fiber respectively with the central point of edge, pile body lower surface, adjacent two axial optical fibers for starting point is around on pile body, 3 anti-S type optical fiber respectively with the central point of edge, pile body lower surface, adjacent two axial optical fibers for starting point is around on pile body.

Application monitoring system carries out the method for pile body three dimensional strain and force parameter measurement, it is characterized in that: the strain variation amount being measured A, B, C tri-test points on a certain cross section of pile body by Brillouin's (FBG) demodulator, the strain value of the anti-S type optical fiber of A, B, C 3, axial optical fiber and S type optical fiber actual measurement is respectively ε _a1, ε _a2, ε _a3, ε _b1, ε _b2, ε _b3, ε _c1, ε _c2, ε _c3, adopt the analytical calculation of three-dimensional strain rosette Computing Principle;

It is as follows that force and moment under strain testing value and foundation pile rectangular coordinate system OXYZ sets up measured equation group, and foundation pile rectangular coordinate system OXYZ is with the center of circle, pile body lower surface for initial point, and be upwards Z axis forward along pile body axis, A point is positioned in the plane of X=0:

$\left[\begin{array}{c}{\mathrm{\&epsiv;}}_{A1}\\ {\mathrm{\&epsiv;}}_{A2}\\ {\mathrm{\&epsiv;}}_{A3}\\ {\mathrm{\&epsiv;}}_{B1}\\ {\mathrm{\&epsiv;}}_{B2}\\ {\mathrm{\&epsiv;}}_{B3}\\ {\mathrm{\&epsiv;}}_{C1}\\ {\mathrm{\&epsiv;}}_{C2}\\ {\mathrm{\&epsiv;}}_{C3}\end{array}\right]=\frac{1}{E}\left[\begin{array}{cccccc}\frac{2\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{16{\sin }^2}{{\mathrm{\&pi;d}}^3}& 0\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& \frac{16{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& 0\\ -\frac{2\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{16{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& 0\\ -\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0\\ \frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}\\ -\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0\\ \frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}\end{array}\right]\left[\begin{array}{c}{F}_X\\ F_Y\\ N_Z\\ T_{}\\ M_X\\ M_Y\end{array}\right]$

F in above formula _x, F _y, N _z, T, M _xand M _ybe respectively lower three power of foundation pile rectangular coordinate system and three moments, wherein F _xfor X is to power, F _yfor Y-direction power, N _zfor Z-direction power, T is moment of torsion, M _xfor the moment of flexure relative to X-axis, M _yfor the moment of flexure relative to Y-axis; E is pile body modulus of elasticity, and d is pile body diameter, and μ is pile body poisson's ratio;

According to strain testing principle, the force and moment under strain testing value foundation pile rectangular coordinate system is expressed as:

${\mathrm{\&epsiv;}}_k^{*}=A_{k1}{F}_X+A_{k2}{F}_Y+A_{k3}{N}_Z+A_{k4}T+A_{k5}{M}_X+A_{k6}{M}_Y;$

In formula, k=3 (i-1)+j, i are the numbering of test point, i=1,2,3; J is the numbering corresponding to test value equation in test point, j=1,2,3; for test value; A _k1~ A _k6for the force parameter coefficient of test value equation, its expression formula is respectively:

$A_{11}=\frac{2\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{12}=0,A_{13}=\frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{14}=0,A_{15}=\frac{16{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{16}=0,$

$A_{21}=0,A_{22}=0,A_{23}=\frac{4}{{\mathrm{\&pi;d}}^{2}E},A_{24}=0,A_{25}=0,A_{26}=0,$

$A_{31}=-\frac{2\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{32}=0,A_{33}=\frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{34}=0,A_{35}=\frac{16{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{36}=0,$

$A_{41}=-\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{42}=\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{43}=\frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{44}=-\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{45}=\frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{46}=\frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},$

$A_{51}=0,A_{52}=0,A_{53}=\frac{4}{{\mathrm{\&pi;d}}^{2}E},A_{54}=0,A_{55}=0,A_{56}=0,$

$A_{61}=-\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{62}=-\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{63}=\frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{64}=-\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{65}=\frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{66}=\frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},$

$A_{71}=-\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{72}=-\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{73}=\frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{74}=\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{75}=\frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{76}=\frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},$

$A_{81}=0,A_{82}=0,A_{83}=\frac{4}{{\mathrm{\&pi;d}}^{2}E},A_{84}=0,A_{85}=0,A_{86}=0,$

$A_{91}=\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{92}=\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{93}=\frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{2}E},A_{94}=\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{95}=\frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},A_{96}=\frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^{3}E},$

The test data choosing more than 6 different pile body cross sections calculates, and adopt principle of least square method to solve force parameter optimum value, calculating can adopt more than 6 equations, then comprehensively analyzes each result of calculation, and determine to take value, its calculation equation is as follows:

$\left[\begin{array}{cccc}\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}^2& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{A}_{k1}& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{A}_{k1}\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{A}_{k2}& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}^2& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{A}_{k2}\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{A}_{k6}& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{A}_{k6}& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}^2\end{array}\right]\left\{\begin{array}{c}{F}_x\\ F_y\\ .\\ .\\ .\\ M_Y\end{array}\right\}=\left\{\begin{array}{c}\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{\mathrm{\&epsiv;}}_k^{*}\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{\mathrm{\&epsiv;}}_k^{*}\\ .\\ .\\ .\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{\mathrm{\&epsiv;}}_k^{*}\end{array}\right\}.$

The invention has the beneficial effects as follows: the present invention proposes based on Distributed Optical Fiber Sensing Techniques foundation pile three dimensional strain and force parameter monitoring system and method for measurement thereof, by burying 9 sensor fibres underground along pile body surface, axial ray, S type light and anti-S type light meet at a bit, form test point, and three test point cross sections altogether, adopt Brillouin's demodulation techniques (BOTDR/BOTDA) to monitor the line strain change of 9 sensor fibres simultaneously, the strain variation amount recorded, according to three-dimensional strain rosette Computing Principle, analyze the axial strain of each joint, shearing strain and shear strain, according to the material parameter of foundation pile, calculate the pile shaft force of foundation pile, horizontal force, moment of flexure, the value of moment of torsion and the regularity of distribution thereof.

The present invention establish a set of comprise distributed sensing fiber, BOTDR/BOTDA and data processing three part composition measurement system, for the strain capacity in Real-Time Monitoring foundation pile each cross section under complicated loads, the Stress property etc. of computation and analysis foundation pile.

Accompanying drawing explanation

Fig. 1 is the structural representation of embodiment.

Fig. 2 is the end view of foundation pile in embodiment.

Fig. 3 is that in embodiment, sensor fibre arranges foundation pile side expanded view.

Fig. 4, Fig. 5 are three-dimensional strain rosette Computing Principle schematic diagram in embodiment.

Fig. 6 is the cross sectional representation in the present embodiment with test point.

Detailed description of the invention

The present embodiment is a kind of foundation pile pile body three dimensional strain and force parameter monitoring system, 9 sensor fibres are buried underground along pile body 3 surface, wherein sensor fibre is divided into three groups, and often organizing 3: first group of sensor fibre is axial optical fiber 11, and 3 sensor fibres are all axial arranged along pile body 3; Second group of sensor fibre is that S type optical fiber 12,3 sensor fibres are around on pile body 3 all counterclockwise, from pile body one end evenly around to the other end; 3rd group of sensor fibre is that anti-S type optical fiber 13,3 sensor fibres are around on pile body all clockwise, from pile body one end evenly around to the other end.Axial optical fiber and S type optical fiber and anti-S type optical fiber all have some joinings, and with the joining of S type optical fiber with overlap with the joining one_to_one corresponding of anti-S type optical fiber and form test point on every root axial optical fiber, the edge of each test point place pile body cross section has three test points 14.In this example, the angle of S type optical fiber, anti-S type optical fiber and axial optical fiber is θ, 0 ° of < θ <90.

As shown in FIG. 1 to 3, the arrangement that in this example, sensor fibre is concrete is that 3 axial optical fibers are evenly arranged in pile body surface, 3 S type optical fiber respectively with the central point of edge, pile body lower surface, adjacent two axial optical fibers for starting point is around on pile body, 3 anti-S type optical fiber respectively with the central point of edge, pile body lower surface, adjacent two axial optical fibers for starting point is around on pile body.Because axial optical fiber is evenly arranged on pile body, S type optical fiber and anti-S type optical fiber starting point are the central point of edge, pile body lower surface, adjacent two axial optical fibers, and S type optical fiber is identical with axial optical fiber angle with anti-S type optical fiber, thus ensures on axial optical fiber with the joining of S type optical fiber and overlap with the joining one_to_one corresponding of anti-S type optical fiber.

9 sensor fibre formation from beginning to end, 1 optical fiber in the present embodiment, the optical fiber two ends formed are connected with Brillouin's (FBG) demodulator, and this Brillouin's (FBG) demodulator is commercial products, and its performance, structure, purposes etc. are not described herein.

Below describe the method that application the present embodiment foundation pile pile body three dimensional strain monitoring system carries out pile body three dimensional strain and force parameter measurement in detail:

(1) Brillouin's demodulation techniques (BOTDR/BOTDA) general principle

BOTDR/BOTDA is that the one grown up on the basis of optical fiber and Fibre Optical Communication Technology is carrier with light, optical fiber is medium, the New Sensing Technology of perception and transmission outer signals.Its operating principle is respectively from optical fiber two ends injected pulse light and continuous light, manufacture Brillouin amplification effect (excited Brillouin), according to optical signal Brillouin shift and the linear changing relation between fiber optic temperature and axial strain, such as formula (1).

Δv _B＝C _vt·Δt+C _ve·Δε(1)

Δ v in formula (1) _bfor Brillouin shift amount; C _{ν t}for Brillouin shift temperature coefficient; C _{ν e}for the Brillouin shift coefficient of strain; Δ t is temperature variation; Δ ε is strain variation amount.

The Brillouin shift that variations in temperature causes compensates by leaving standstill in non-test section the frequency displacement obtained.

(2) three-dimensional strain rosette Computing Principle

As shown in Figure 4, Figure 5, definition OXYZ is foundation pile rectangular coordinate system, oxyz is the local coordinate system of test point, in foundation pile rectangular coordinate system with center, pile body lower surface for the origin of coordinates, be upwards Z axis forward along pile body axis, in the local coordinate system of test point, test point is origin of coordinates o, x-axis is along foundation pile cross-wise direction, y-axis is fiber arrangement direction vertically, and wherein x-axis and y-axis are D with the angle of X-axis and Y-axis respectively, and z-axis is vertical with Z axis.

Suppose that the x of M point on pile body cross section is respectively ε to strain, y to strain and shear strain _x, ε _y, γ _xy, then the strain in 0 ° (axial optical fiber), θ (anti-S type optical fiber) ,-θ (S type optical fiber) three directions is respectively:

ε _0°＝ε _y(2)

${\mathrm{\&epsiv;}}_{\mathrm{\&theta;}}=\frac{{\mathrm{\&epsiv;}}_x+{\mathrm{\&epsiv;}}_y}{2}-\frac{{\mathrm{\&epsiv;}}_x-{\mathrm{\&epsiv;}}_y}{2}\cos 2\mathrm{\&theta;}+\frac{{\mathrm{\&gamma;}}_{\mathrm{xy}}}{2}\sin 2\mathrm{\&theta;}---\left(3\right)$

${\mathrm{\&epsiv;}}_{-\mathrm{\&theta;}}=\frac{{\mathrm{\&epsiv;}}_x+{\mathrm{\&epsiv;}}_y}{2}-\frac{{\mathrm{\&epsiv;}}_x-{\mathrm{\&epsiv;}}_y}{2}\cos 2\mathrm{\&theta;}-\frac{{\mathrm{\&gamma;}}_{\mathrm{xy}}}{2}\sin 2\mathrm{\&theta;}---\left(4\right)$

Solved by formula (2), (3), (4) simultaneous equations:

${\mathrm{\&epsiv;}}_x=\frac{{\mathrm{\&epsiv;}}_{-\mathrm{\&theta;}}+{\mathrm{\&epsiv;}}_{\mathrm{\&theta;}}-{2\mathrm{\&epsiv;}}_0{\cos }^2\mathrm{\&theta;}}{2{\sin }^2\mathrm{\&theta;}}---\left(5\right)$

ε _y＝ε _0°(6)

${\mathrm{\&gamma;}}_{\mathrm{xy}}=\frac{{\mathrm{\&epsiv;}}_{\mathrm{\&theta;}}-{\mathrm{\&epsiv;}}_{-\mathrm{\&theta;}}}{\sin 2\mathrm{\&theta;}}---\left(7\right)$

Choose a pile body cross section with test point and carry out three dimensional strain analysis, as described in Figure 6, on this cross section, test point is A, B, C 3 point, and A point is positioned at X=0 plane, then:

If the strain value that A point 0 ° of (axial optical fiber), θ (anti-S type optical fiber) ,-θ (S type optical fiber) survey is respectively ε _a1, ε _a2, ε _a3, the strain value that B point 0 ° of (axial optical fiber), θ (anti-S type optical fiber) ,-θ (S type optical fiber) survey is respectively ε _b1, ε _b2, ε _b3, the strain value that C point 0 ° of (axial optical fiber), θ (anti-S type optical fiber) ,-θ (S type optical fiber) survey is respectively ε _c1, ε _c2, ε _c3.

Six components of strain in OXYZ coordinate system represent with { ε }, and six components of strain in oxyz coordinate system represent with { ε ' }.Following coordinate transformation relation should be met between two groups of components of strain:

$\left\{\begin{array}{c}{\mathrm{\&epsiv;}}_{X^{\&prime;}}\\ {\mathrm{\&epsiv;}}_{Y^{\&prime;}}\\ {\mathrm{\&epsiv;}}_{Z^{\&prime;}}\\ {\mathrm{\&gamma;}}_{X^{\&prime;}{Y}^{\&prime;}}\\ {\mathrm{\&gamma;}}_{X^{\&prime;}{Y}^{\&prime;}}\\ {\mathrm{\&gamma;}}_{Z^{\&prime;}{X}^{\&prime;}}\end{array}\right\}=\left[\begin{array}{cccccc}{l}_1^2& m_1^2& n_1^2& {2l}_1{m}_1& {2m}_1{n}_1& {2n}_1{l}_1\\ l_2^2& m_2^2& n_2^2& {2l}_2{m}_2& {2m}_2{n}_2& {2n}_2{l}_2\\ l_3^2& m_3^2& n_3^2& {2l}_3{m}_3& {2m}_3{n}_3& {2n}_3{l}_3\\ l_1{l}_2& m_1{m}_2& n_1{n}_2& l_1{m}_2+l_2{m}_1& m_1{l}_2+m_2{n}_1& n_1{l}_2+n_2{l}_1\\ l_2{l}_3& m_1{m}_2& n_1{n}_2& l_2{m}_3+l_3{m}_2& m_2{n}_3+m_3{n}_2& n_2{l}_3+n_3{l}_2\\ l_1{l}_3& m_1{m}_3& n_1{n}_3& l_1{m}_3+l_3{m}_1& m_1{n}_3+m_3{n}_1& n_1{l}_3+n_3{l}_1\end{array}\right]\left\{\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right\}---\left(8\right)$

The coordinate axes at test point place and the direction cosines of foundation pile rectangular coordinate system can be expressed as follows:

l ₁＝cosD,l ₂＝sinVsinD,l ₃＝cosVsinD

m ₁＝-sinD,m ₂＝sinVcosD,m ₃＝cosVcosD

n ₁＝0,n ₂＝-cosV,n ₃＝sinV(9)

Get azimuth, A, B, C 3 places and be respectively 0 °, 120 ° and 240 °, inclination angle is 90 °.According to three-dimensional strain rosette principle, in conjunction with space coordinate conversion formula, the relation setting up the line strain of measuring point three-dimensional and foundation pile steric strain parameter is as follows:

$\left[\begin{array}{c}{\mathrm{\&epsiv;}}_{A1}\\ {\mathrm{\&epsiv;}}_{A2}\\ {\mathrm{\&epsiv;}}_{A3}\end{array}\right]=\left[\begin{array}{cccccc}0& \frac{1-\cos 2\mathrm{\&theta;}}{2}& \frac{1+\cos 2\mathrm{\&theta;}}{2}& 0& \frac{\sin 2\mathrm{\&theta;}}{2}& 0\\ 0& 0& 1& 0& 0& 0\\ 0& \frac{1-\cos 2\mathrm{\&theta;}}{2}& \frac{1+\cos 2\mathrm{\&theta;}}{2}& 0& -\frac{\sin 2\mathrm{\&theta;}}{2}& 0\end{array}\right]\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]$

$\begin{array}{c}\left[\begin{array}{c}{\mathrm{\&epsiv;}}_{B1}\\ {\mathrm{\&epsiv;}}_{B2}\\ {\mathrm{\&epsiv;}}_{B3}\end{array}\right]=\left[\begin{array}{cccccc}0& \frac{1-\cos 2\mathrm{\&theta;}}{2}& \frac{1+\cos 2\mathrm{\&theta;}}{2}& 0& \frac{\sin 2\mathrm{\&theta;}}{2}& 0\\ 0& 0& 1& 0& 0& 0\\ 0& \frac{1-\cos 2\mathrm{\&theta;}}{2}& \frac{1+\cos 2\mathrm{\&theta;}}{2}& 0& -\frac{\sin 2\mathrm{\&theta;}}{2}& 0\end{array}\right]\left[\begin{array}{cccccc}\frac{1}{4}& \frac{3}{4}& 0& \frac{\sqrt{3}}{2}& 0& 0\\ \frac{3}{4}& \frac{1}{4}& 0& -\frac{\sqrt{3}}{2}& 0& 0\\ 0& 0& 1& 0& 0& 0\\ -\frac{\sqrt{3}}{4}& \frac{\sqrt{3}}{4}& 0& -\frac{1}{2}& 0& 0\\ 0& 0& 0& 0& -\frac{1}{2}& \frac{\sqrt{3}}{2}\\ 0& 0& 0& 0& -\frac{\sqrt{3}}{2}& -\frac{1}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]\\ =\left[\begin{array}{cccccc}\frac{3}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{2}(1+\cos 2\mathrm{\&theta;})& -\frac{\sqrt{3}}{4}(1-\cos 2\mathrm{\&theta;})& -\frac{1}{4}\sin 2\mathrm{\&theta;}& \frac{\sqrt{3}}{4}\sin 2\mathrm{\&theta;}\\ 0& 0& 1& 0& 0& 0\\ \frac{3}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{2}(1+\cos 2\mathrm{\&theta;})& -\frac{\sqrt{3}}{4}(1-\cos 2\mathrm{\&theta;})& \frac{1}{4}\sin 2\mathrm{\&theta;}& -\frac{\sqrt{3}}{4}\sin 2\mathrm{\&theta;}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]\end{array}$

$\begin{array}{c}\left[\begin{array}{c}{\mathrm{\&epsiv;}}_{C1}\\ {\mathrm{\&epsiv;}}_{C2}\\ {\mathrm{\&epsiv;}}_{C3}\end{array}\right]=\left[\begin{array}{cccccc}0& \frac{1-\cos 2\mathrm{\&theta;}}{2}& \frac{1+\cos 2\mathrm{\&theta;}}{2}& 0& \frac{\sin 2\mathrm{\&theta;}}{2}& 0\\ 0& 0& 1& 0& 0& 0\\ 0& \frac{1-\cos 2\mathrm{\&theta;}}{2}& \frac{1+\cos 2\mathrm{\&theta;}}{2}& 0& -\frac{\sin 2\mathrm{\&theta;}}{2}& 0\end{array}\right]\left[\begin{array}{cccccc}\frac{1}{4}& \frac{3}{4}& 0& -\frac{\sqrt{3}}{2}& 0& 0\\ \frac{3}{4}& \frac{1}{4}& 0& \frac{\sqrt{3}}{2}& 0& 0\\ 0& 0& 1& 0& 0& 0\\ \frac{\sqrt{3}}{4}& -\frac{\sqrt{3}}{4}& 0& -\frac{1}{2}& 0& 0\\ 0& 0& 0& 0& -\frac{1}{2}& -\frac{\sqrt{3}}{2}\\ 0& 0& 0& 0& \frac{\sqrt{3}}{2}& -\frac{1}{2}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]\\ =\left[\begin{array}{cccccc}\frac{3}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{8}(1-\mathrm{c\; os}2\mathrm{\&theta;})& \frac{1}{2}(1+\cos 2\mathrm{\&theta;})& \frac{\sqrt{3}}{4}(1-\cos 2\mathrm{\&theta;})& -\frac{1}{4}\sin 2\mathrm{\&theta;}& \frac{\sqrt{3}}{4}\sin 2\mathrm{\&theta;}\\ 0& 0& 1& 0& 0& 0\\ \frac{3}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{8}(1-\cos 2\mathrm{\&theta;})& \frac{1}{2}(1+\cos 2\mathrm{\&theta;})& \frac{\sqrt{3}}{4}(1-\cos 2\mathrm{\&theta;})& \frac{1}{4}\sin 2\mathrm{\&theta;}& -\frac{\sqrt{3}}{4}\sin 2\mathrm{\&theta;}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]\end{array}---\left(10\right)$

(3) axle power, moment of flexure, torque arithmetic theory and principle

According to the three-dimensional line strain calculated and shear strain, then can obtain axle power, horizontal force, moment of flexure and moment of torsion suffered by pile body under foundation pile rectangular coordinate system by theory of mechanics of materials is:

$\left[\begin{array}{c}{F}_X\\ F_Y\\ N_Z\\ T\\ M_X\\ M_Y\end{array}\right]=E\left[\begin{array}{cccccc}0& 0& 0& 0& \frac{{\mathrm{\&pi;d}}^2}{4}& 0\\ 0& 0& 0& 0& 0& \frac{{\mathrm{\&pi;d}}^2}{4}\\ 0& 0& \frac{{\mathrm{\&pi;d}}^2}{4}& 0& 0& 0\\ 0& 0& 0& \frac{{\mathrm{\&pi;d}}^3}{32(1+\mathrm{\&mu;})}& 0& 0\\ 0& \frac{{\mathrm{\&pi;d}}^3}{16}& 0& 0& 0& 0\\ \frac{{\mathrm{\&pi;d}}^3}{16}& 0& 0& 0& 0& 0\end{array}\right]\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&gamma;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]---\left(11\right)$

In formula, E is pile body modulus of elasticity, and d is pile body diameter, and μ is pile body poisson's ratio.F _x, F _y, N _z, T, M _xand M _ybe respectively lower three power of foundation pile rectangular coordinate system and three moments, wherein F _xfor X is to power, F _yfor Y-direction power, N _zfor Z-direction power, T is moment of torsion, M _xfor the moment of flexure relative to X-axis, M _yfor the moment of flexure relative to Y-axis.

Then steric strain component Parametric Representation of exerting oneself is:

$\left[\begin{array}{c}{\mathrm{\&epsiv;}}_X\\ {\mathrm{\&epsiv;}}_Y\\ {\mathrm{\&epsiv;}}_Z\\ {\mathrm{\&epsiv;}}_{\mathrm{XY}}\\ {\mathrm{\&gamma;}}_{\mathrm{YZ}}\\ {\mathrm{\&gamma;}}_{\mathrm{ZX}}\end{array}\right]=\frac{1}{E}\left[\begin{array}{cccccc}0& 0& 0& 0& 0& \frac{16}{{\mathrm{\&pi;d}}^3}\\ 0& 0& 0& 0& \frac{16}{{\mathrm{\&pi;d}}^3}& 0\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0\\ 0& 0& 0& \frac{32(1+\mathrm{\&mu;})}{{\mathrm{\&pi;d}}^3}& 0& 0\\ \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0& 0& 0\\ 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0& 0\end{array}\right]\left[\begin{array}{c}{F}_X\\ F_Y\\ N_Z\\ T\\ M_X\\ M_Y\end{array}\right]---\left(12\right)$

Force and moment under strain testing value and foundation pile rectangular coordinate system OXYZ sets up measured equation group, as follows:

${\mathrm{\&epsiv;}}_k^{*}=\left[\begin{array}{c}{\mathrm{\&epsiv;}}_{A1}\\ {\mathrm{\&epsiv;}}_{A2}\\ {\mathrm{\&epsiv;}}_{A3}\\ {\mathrm{\&epsiv;}}_{B1}\\ {\mathrm{\&epsiv;}}_{B2}\\ {\mathrm{\&epsiv;}}_{B3}\\ {\mathrm{\&epsiv;}}_{C1}\\ {\mathrm{\&epsiv;}}_{C2}\\ {\mathrm{\&epsiv;}}_{C3}\end{array}\right]=\frac{1}{E}\left[\begin{array}{cccccc}\frac{2\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{16{\sin }^2}{{\mathrm{\&pi;d}}^3}& 0\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& \frac{16{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& 0\\ -\frac{2\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& 0& \frac{16{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& 0\\ -\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0\\ \frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}\\ -\frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& -\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}\\ 0& 0& \frac{4}{{\mathrm{\&pi;d}}^2}& 0& 0& 0\\ \frac{\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^2}& \frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{{\mathrm{\&pi;d}}^3}\end{array}\right]\left[\begin{array}{c}{F}_X\\ F_Y\\ N_Z\\ T_{}\\ M_X\\ M_Y\end{array}\right]---\left(13\right)$

According to strain testing principle, the force and moment under strain testing value foundation pile rectangular coordinate system is expressed as:

${\mathrm{\&epsiv;}}_k^{*}=A_{k1}{F}_X+A_{k2}{F}_Y+A_{k3}{N}_Z+A_{k4}T+A_{k5}{M}_X+A_{k6}{M}_Y---\left(14\right)$

In formula, k=3 (i-1)+j, i are the numbering of test point, i=1,2,3; J is the numbering corresponding to test value equation in test point, j=1,2,3; for test value; A _k1~ A _k6for the force parameter coefficient of test value equation.The test data choosing multiple different pile body cross section calculates, and the equation number of measured equation group (14), more than non-coplanar force unknown quantity (6 components) number of demand solution, adopts principle of least square method to solve force parameter optimum value.Calculating can adopt and be no less than 6 equations, then comprehensively analyzes each result of calculation, determines to take value.Its calculation equation is as follows:

$\left[\begin{array}{cccc}\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}^2& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{A}_{k1}& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{A}_{k1}\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{A}_{k2}& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}^2& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{A}_{k2}\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{A}_{k6}& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{A}_{k6}& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}^2\end{array}\right]\left\{\begin{array}{c}{F}_x\\ F_y\\ .\\ .\\ .\\ M_Y\end{array}\right\}=\left\{\begin{array}{c}\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{\mathrm{\&epsiv;}}_k^{*}\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{\mathrm{\&epsiv;}}_k^{*}\\ .\\ .\\ .\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{\mathrm{\&epsiv;}}_k^{*}\end{array}\right\}---\left(15\right)$

Claims (3)

1. foundation pile pile body three dimensional strain and a force parameter monitoring system, is characterized in that: bury 9 sensor fibres underground along pile body (3) surface, sensor fibre is divided into three groups, often organizes 3;

First group of sensor fibre is axial optical fiber (11), and 3 sensor fibres are all axial arranged along pile body (3); Second group of sensor fibre is S type optical fiber (12), and 3 sensor fibres are around on pile body (3) all counterclockwise, from pile body one end evenly around to the other end; 3rd group of sensor fibre is anti-S type optical fiber (13), and 3 sensor fibres are around on pile body (3) all clockwise, from pile body one end evenly around to the other end;

Described axial optical fiber (11) and S type optical fiber (12), anti-S type optical fiber (13) all have some joinings, and with the joining of S type optical fiber with overlap with the joining one_to_one corresponding of anti-S type optical fiber and form test point (14) on every root axial optical fiber, the edge of each test point place pile body cross section has three test points; The angle of described S type optical fiber, anti-S type optical fiber and axial optical fiber is θ, 0 ° of < θ <90;

9 sensor fibre formation from beginning to end, 1 optical fiber, the optical fiber two ends formed are connected with Brillouin's (FBG) demodulator (2).

2. foundation pile pile body three dimensional strain according to claim 1 and force parameter monitoring system, it is characterized in that: 3 axial optical fibers (11) are evenly arranged in pile body (3) surface, 3 S type optical fiber (12) are that starting point is around on pile body with the central point of pile body (3) edge, lower surface, adjacent two axial optical fibers (11) respectively, and 3 anti-S type optical fiber (13) are that starting point is around on pile body with the central point of edge, pile body lower surface, adjacent two axial optical fibers (11) respectively.

3. application rights requires that monitoring system described in 1 or 2 carries out the method for pile body three dimensional strain and force parameter measurement, it is characterized in that: the strain variation amount being measured A, B, C tri-test points on a certain cross section of pile body by Brillouin's (FBG) demodulator (2), the strain value that the anti-S type optical fiber (13) of A, B, C 3, axial optical fiber (11) and S type optical fiber (12) are surveyed is respectively ε _a1, ε _a2, ε _a3, ε _b1, ε _b2, ε _b3, ε _c1, ε _c2, ε _c3, adopt the analytical calculation of three-dimensional strain rosette Computing Principle;

It is as follows that force and moment under strain testing value and foundation pile rectangular coordinate system OXYZ sets up measured equation group, and foundation pile rectangular coordinate system OXYZ is with pile body (3) center of circle, lower surface for initial point, and be upwards Z axis forward along pile body axis, A point is positioned in the plane of X=0:

$\left[\begin{array}{c}{\mathrm{\&epsiv;}}_{A1}\\ {\mathrm{\&epsiv;}}_{A2}\\ {\mathrm{\&epsiv;}}_{A3}\\ {\mathrm{\&epsiv;}}_{B1}\\ {\mathrm{\&epsiv;}}_{B2}\\ {\mathrm{\&epsiv;}}_{B3}\\ {\mathrm{\&epsiv;}}_{C1}\\ {\mathrm{\&epsiv;}}_{C2}\\ {\mathrm{\&epsiv;}}_{C3}\end{array}\right]=\frac{1}{E}\left[\begin{array}{cccccc}\frac{2\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& 0& \frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& 0& \frac{16{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& 0\\ 0& 0& \frac{4}{\mathrm{\&pi;}{d}^2}& 0& 0& 0\\ -\frac{2\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& 0& \frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& 0& \frac{16{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& 0\\ -\frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& -\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}\\ 0& 0& \frac{4}{\mathrm{\&pi;}{d}^2}& 0& 0& 0\\ \frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& -\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& -\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}\\ -\frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& -\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}\\ 0& 0& \frac{4}{\mathrm{\&pi;}{d}^2}& 0& 0& 0\\ \frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^2}& \frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}& \frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^3}\end{array}\right]\left[\begin{array}{c}{F}_X\\ F_Y\\ N_Z\\ T\\ M_X\\ M_Y\end{array}\right]$

F in above formula _x, F _y, N _z, T, M _xand M _ybe respectively lower three power of foundation pile rectangular coordinate system and three moments, wherein F _xfor X is to power, F _yfor Y-direction power, N _zfor Z-direction power, T is moment of torsion, M _xfor the moment of flexure relative to X-axis, M _yfor the moment of flexure relative to Y-axis; E is pile body modulus of elasticity, and d is pile body diameter, and μ is pile body poisson's ratio;

According to strain testing principle, the force and moment under strain testing value foundation pile rectangular coordinate system is expressed as:

${\mathrm{\&epsiv;}}_k^{*}=A_{k1}{F}_X+A_{k2}{F}_Y+A_{k3}{N}_Z+A_{k4}T+A_{k5}{M}_X+A_{k6}{M}_Y;$

In formula, k=3 (i-1)+j, i are the numbering of test point, i=1,2,3; J is the numbering corresponding to test value equation in test point, j=1,2,3; for test value; A _k1~ A _k6for the force parameter coefficient of test value equation, its expression formula is respectively:

$A_{11}=\frac{2\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{12}=0,A_{13}=\frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{14}=0,A_{15}=\frac{16{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{16}=0,$

$A_{21}=0,A_{22}=0,A_{23}=\frac{4}{\mathrm{\&pi;}{d}^{2}E},A_{24}=0,A_{25}=0,A_{26}=0,$

$A_{31}=-\frac{2\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{32}=0,A_{33}=\frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{34}=0,A_{35}=\frac{16{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{36}=0,$

$A_{41}=-\frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{42}=\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{43}=\frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{44}=-\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{45}=\frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{46}=\frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},$

$A_{51}=0,A_{52}=0,A_{53}=\frac{4}{\mathrm{\&pi;}{d}^{2}E},A_{54}=0,A_{55}=0,A_{55}=0,$

$A_{61}=\frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{62}=-\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{63}=\frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{64}=-\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{65}=\frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{66}=\frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},$

$A_{71}=-\frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{72}=-\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{73}=\frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{74}=\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{75}=\frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{76}=\frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},$

$A_{81}=0,A_{82}=0,A_{83}=\frac{4}{\mathrm{\&pi;}{d}^{2}E},A_{84}=0,A_{85}=0,A_{86}=0,$

$A_{91}=\frac{\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{92}=\frac{\sqrt{3}\sin 2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{93}=\frac{4{\cos }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{2}E},A_{94}=\frac{16\sqrt{3}(1+\mathrm{\&mu;}){\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{95}=\frac{4{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},A_{96}=\frac{12{\sin }^2\mathrm{\&theta;}}{\mathrm{\&pi;}{d}^{3}E},$

The test data choosing more than 6 different pile body cross sections calculates, and adopt principle of least square method to solve force parameter optimum value, calculating can adopt more than 6 equations, then comprehensively analyzes each result of calculation, and determine to take value, its calculation equation is as follows:

$\left[\begin{array}{cccc}\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}^2& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{A}_{k1}& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{A}_{k1}\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{A}_{k2}& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}^2& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{A}_{k2}\\ .& .& .& .\\ .& .& .& .\\ .& \text{.}& .& .\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{A}_{k6}& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{A}_{k6}& ...& \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}^2\end{array}\right]\left\{\begin{array}{c}{F}_x\\ F_y\\ .\\ .\\ .\\ M_Y\end{array}\right\}=\left\{\begin{array}{c}\underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k1}{\mathrm{\&epsiv;}}_k^{*}\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k2}{\mathrm{\&epsiv;}}_k^{*}\\ .\\ .\\ .\\ \underset{k=1}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{k6}{\mathrm{\&epsiv;}}_k^{*}\end{array}\right\}.$