CN105043345A - Distributed settlement measurement device and measurement method - Google Patents

Abstract

The invention relates to a distributed settlement measurement device and a measurement method. The measurement device comprises continuous fiber composite bars that are in array distribution in a measured foundation and is vertically driven into soil or foundation. The continuous fiber composite bar is composed of a bottom anchoring end, a soil layer sensing rod body, a soil surface anchoring piece and a data line leading-out end. The soil layer sensing rod body internally contains multiple groups of long-gauge strain sensing units spliced in the length direction, the data line leading-out end is located at the upper end of the soil layer sensing rod body and is connected to the long-gauge strain sensing units, soil layer anchoring bolts consolidating each soil layer are arranged outside the splicing position of two long-gauge strain sensing units, the soil surface anchoring piece anchors the soil surface at a soil surface position, and scale is marked outside the soil layer sensing rod body. The device provided by the invention employs the structure to meet the settlement measurement requirements of hard soil layer and soft soil layer foundation in a complex environment, has strong resistance to external interference factors, is suitable for long-term continuous monitoring, has cheap price, and is convenient for construction and realization of multipoint distribution.

Description

A kind of distributed settlement measuring device and measuring method

Technical field

The present invention relates to a kind of technology for health detection and monitoring in civil engineering transport structure, particularly relate to the distributed sedimentometer of a kind of high precision and measuring method thereof.

Background technology

Measuring for the settlement of foundation in the civil engineering transport structures such as such as subway, light rail and overpass, is the important indicator of evaluation Base foundation design or earthen structure design.Engineering practice shows, most of foundation accident is all excessive or uneven by foundation deformation to be caused, so it is vital that the relative settlement on correct measurement and control basis and total settlement make it be no more than allowable value.In recent years, all many-sided research of people to soil mechanics has breakthrough, but to the rare progress of the research of foundation deformation.Traditional subsidence monitoring method comprises measurement of the level, base-rock marker and layering mark and measures, can only meet for the sedimentation change between certain any earth's surface and basic point, be difficult to meet as composite foundation, uneven and sedimentation distributes and the measurement requirement of the complexity such as subsidence rate.

At present in large scale structure health monitoring, increasing research lays particular emphasis on and realizes the object such as Damage Assessment Method, performance evaluation by strain sensing.The easy brittle failure existed in the strain sensing heart yearn relevant with carbon fiber sensing technology with the optical fiber sensing technology based on Brillouin scattering to such as fiber grating sensing technology, heart yearn slippage, gauge length internal strain is uneven, the problem of the key index such as measuring accuracy and sensitivity deficiency, carry out long gauge length design encapsulation, thus realize the stable end anchorage of minute diameter sensing heart yearn, gauge length internal strain/stress homogenization, enhanced sensitivity improves sensitivity design, with gain effect such as raising endurance quality etc., and then realize the large-scale distributed continuous static of multiple spot and dynamic strain measurement in structure, reach in structure as distortion, natural frequency, the deterioration of amount of deflection component, displacement modes, with the calculating of the local such as strain mode and overall configuration state parameter.The long-term detection that patent CN103438815A is civil engineering field of traffic heavy construction structure and health monitoring provide a kind of high durable long gauge length optical fibre grating sensor and manufacture method thereof.Patent CN103868445A provides a kind of distributed high-accuracy long-gauge-length carbon fiber strain detection testing device based on carbon fiber continuous fiber, to provide stable sound state strain measurement.But in addition on the one hand, strain sensing technology is still at the early-stage in the measuring technique of the grounds such as the soil body.Occur being laid in inside soil body according to Fibre Optical Sensor at present, to measure and to monitor sedimentation between anchor point to reference point and distortion.Patent CN102435178A discloses one and makes fiber grating reinforced concrete sensing rod by joints cement outside armored optical cable and fiber grating and reinforcing bar, to monitor the sedimentation of building structure.But fibre diameter is small in reinforcing bar direct combination, is difficult to ensure strain measurement accurately, reinforced concrete stiffness of structural member is large in addition, is unsuitable for the perception to soil deformation in ground.Patent CN103438820A discloses a kind of for borehole sections Rock And Soil layering distortion, and backfill sealing of hole implants the subsidence monitoring method of optical fiber.But due in backfilling process, optical fiber and packing material consolidation as a whole, be unsuitable for the distributed measurement for each soil layer different distortion.In addition fiber optic materials character is soft, when there is tangential displacement in the soil body, is difficult to the accuracy ensureing vertical direction settlement measurement.In addition for the reference point on earth's surface, particularly soft soil foundation, there is cohesive force and be lowly difficult to ensure senser element and soil body cooperative transformation, and during soil erosion, be difficult to the problem ensureing stable datum mark.In addition the influence factor such as water erosion and biology in the soil body, the life requirement for senser element self is high.

Another aspect, along with the development of composite technology, composite reinforcing material technology is more and more applied in the application of Structural Engineering enhancing and performance improvement.Patent Zl103668625A discloses the technology of a kind of plurality of fibers precursor plying, to reach according to suffered Tensity size in designing requirement control fiber precursor and then the object ensureing fiber precursor extension consistency in folded yarn.Patent CN201400819Y discloses and a kind ofly belongs to the made of new structural material of association area such as civil engineering traffic and the Basalt fiber composite rib of version and basalt fibre compound stay cable.In order to implement to measure reliably and monitoring to the stability of composite foundation and subsidence rate, need a kind of settlement measurement method of high precision and high stability.

Summary of the invention

Technical matters to be solved by this invention is the deficiency existed for above-mentioned prior art, and provide a kind of with the soil body harmonious and layering measure the distributed settlement measuring device and measuring method that the soil body becomes.By multipoint mode settlement measurement, measure the strain variation between sedimentometer areal coverage in native off-balancesheet and the soil body respectively, then calculate each section of corresponding distortion, and then obtain total settlement.The present invention can realize the perception to the corresponding sedimentation of soil layer each in composite foundation, high-precision settlement measurement requirement when reference point lost efficacy when realizing occurring sedimentation on a large scale, be suitable for the laying of longitudinal direction and horizontal direction multimetering, and then reach the object evaluating subsidence rate and foundation stability in complicated settlement measurement.

For solving the problems of the technologies described above, the present invention adopts following technical scheme:

A kind of distributed settlement measuring device, is characterized in that: comprise into the continuous fiber composite reinforcing of vertically squeezing into the soil body or basic internal of array distribution at institute's geodetic base, described continuous fiber composite reinforcing is by bottom anchor end, the soil layer sensing body of rod, soil table anchoring sheet and data line exit composition, the many group leaders gauge length strain sensing unit spliced in the longitudinal direction is comprised in described soil layer sensing body of rod inside, described data line exit is positioned at the upper end of the described soil layer sensing body of rod and is connected with described long gauge length strain sensing unit, the soil layer anchoring bolt with each soil consolidation is laid with outside gauge length strain sensing unit spliced position long described in two, described soil table anchoring sheet shows anchoring in native table position and soil, scale is had in the external mark of soil layer sensor bar.

Described should long gauge length change sensing unit be point type electronics strain sensor, optical fiber or carbon fiber strain sensor.

The material of the described soil layer sensing body of rod is carbon fiber, glass fibre or basalt fibre.

A kind of distributed sedimentation device measuring method, is characterized in that, comprise following steps:

Step one, install and measure device: after monitoring point sets vertical shaft, insert and fix described measurement mechanism;

Step 2, measurement and record the strain initial value of online surveying range in the soil body, gauge length that each continuous fiber composite reinforcing section interval covers and native off-balancesheet read initial scale between correction zone,

The gauge length that wherein each continuous fiber composite reinforcing section interval covers is determined by following formula:

$L=\left[\begin{array}{ccccc}{l}_{11}& ...& l_{i1}& ...& l_{m1}\\ & & \·& & \\ & & \·& & \\ & & \·& & \\ l_{1j}& ...& l_{ij}& ...& l_{mj}\\ & & \·& & \\ & & \·& & \\ & & \·& & \\ l_{1n}& ...& l_{in}& ...& l_{mn}\end{array}\right],$

In formula, m is the on-line measurement interval monitoring point number covered in measurement range, and n is the sensing unit group number that in the soil body of each monitoring point, measurement mechanism comprises,

Wherein: in the described soil body, online surveying range is between bottom anchor portion to soil table anchor portion, it is between soil table anchor portion to free end that described native off-balancesheet reads between correction zone;

Step 3: after sedimentation and deformation, in measurement, in the step soil body, online surveying range internal strain changes, and according to each section of interval gauge length, calculates each interval corresponding compression deformation, and directly reads the scale changing value exposed in native off-balancesheet reading correction zone,

Wherein in the soil body, online surveying range internal strain change is determined by following formula:

${\mathrm{\ϵ}}_{(m,n)}=\left[\begin{array}{ccccc}{\mathrm{\ϵ}}_{11}& ...& {\mathrm{\ϵ}}_{i1}& ...& {\mathrm{\ϵ}}_{m1}\\ & & \·& & \\ & & \·& & \\ & & \·& & \\ {\mathrm{\ϵ}}_{1j}& ...& {\mathrm{\ϵ}}_{ij}& ...& {\mathrm{\ϵ}}_{mj}\\ & & \·& & \\ & & \·& & \\ & & \·& & \\ {\mathrm{\ϵ}}_{1n}& ...& {\mathrm{\ϵ}}_{in}& ...& {\mathrm{\ϵ}}_{mn}\end{array}\right],$

Wherein each interval corresponding compression deformation is determined by following formula:

in formula be the interior online measured value of the soil body of i-th monitoring point,

The native off-balancesheet corrected value that wherein each interval is read is determined by following formula:

${\mathrm{\δ}}^2=\left[\begin{array}{ccccc}{\mathrm{\δ}}_1^2& ...& {\mathrm{\δ}}_i^2& ...& {\mathrm{\δ}}_m^2\end{array}\right],$ In formula it is the native off-balancesheet corrected value of i-th monitoring point;

Step 4: in the soil body obtain upper step, online surveying range and native off-balancesheet read the distortion summation between correction zone, obtain bulk settling amount,

The total settlement that wherein each interval is integrated is determined by following formula:

δ in formula _iit is the total settlement of i-th monitoring point.

The method of fixing described measurement mechanism in described step one is: utilize pressing method that resin bag pressure is entered silo bottom until stable rock stratum place; Rack resin bag by rotating described measurement body and be stirred to the complete consolidation of resin.

The measurement body of settlement measuring device of the present invention comprises online surveying range and native off-balancesheet in the soil body and reads between correction zone; Due to continuous fiber composite reinforcing material, anchoring sheet and soil body anchoring is shown by bottom anchored end and soil, cause continuous fiber composite reinforcing material generation compression deformation when soil layer generation sedimentation, its displacement transfer realizes perception to strain sensing unit, forms online surveying range in the soil body; Strain sensing unit, by soil layer anchoring bolt with corresponding soil consolidation and cooperative transformation, realizes the perception to the different settling amount of each soil layer; Strain sensing unit, must implant enough pre-tensor in advance and measure requirement with the compression deformation meeting each section of the body of rod; Junction between strain sensing unit, must have stable rigidity Design to avoid slippage and the primary creep of strain sensing unit inside; Described each group leader's gauge length strain sensing unit two ends correspondence position is laid with soil layer anchoring bolt, described soil layer anchoring bolt is realized and each soil consolidation by the expansion burr outside the continuous fiber composite reinforcing material body of rod, hydraulic expansion crab-bolt can be adopted simultaneously, crab-bolt outer wall generation permanent strain after utilizing water under high pressure to inject, reaches the segmentation anchoring object of the complete consolidation with the soil body;

Strain sensing unit is point type electronics strain sensor or optical fiber or carbon fiber strain sensor; Can adopt point type electronics strain sensor for the settlement monitoring project that detection requirement is not high, its sensing element must be installed on the elasticity Force transmission parts such as cable wire or wire of the distributed sedimentometer inside of high precision by the mode of two ends anchoring; Require that the large settlement monitoring project of height and the monitoring degree of depth and scope can adopt fiber strain sensing element for monitoring accuracy, its sensing element can be fiber grating or the sensing mode based on Brillouin scattering technology; Require that high settlement monitoring project can adopt carbon fiber strain sensor for decay resistance, its sensing element can be bridge measurement mode or the sensing mode based on electronics Time Domain Reflectometry.

Feature of the present invention is the anchoring sheet that the bottom anchored end by anchoring into stable rock stratum is shown with soil, to ensure the accuracy of vertical direction settlement measurement; By soil layer anchoring bolt and the strain sensing unit of each section of the body of rod, realize each soil layer distortion sectional monitoring; Due to burr and the segmentation anchoring bolt structure of the body of rod, ensure the accuracy of each soil layer measurement result; Even if to the monitoring target of bond hypodynamic Soft Soil Layer and severe water and soil erosion, the correction zone still by carrying, conveniently realizes the correction of measurement result.

Accompanying drawing explanation

Fig. 1 is structural drawing of the present invention.

Fig. 2 is that the present invention installs rear schematic diagram.

Fig. 3 is principle of work schematic diagram of the present invention.

Fig. 4 is cross section of the present invention and longitudinally lays schematic diagram.

Fig. 5 is the present invention's monitoring network schematic diagram completely.

Wherein:

1-soil table anchored end; 2-strain sensing unit; 3-junction surface; 4-bottom anchor end; 5-free end; 6-transfer wire; 7-data transmission device; 8-rock stratum; 9-soil layer one; 10-soil layer two; 11-soil layer three; In the A1-soil body, in online surveying range, soil layer 1 is corresponding interval; In the A2-soil body, in online surveying range, soil layer 2 is corresponding interval; In the A3-soil body, in online surveying range, soil layer 3 should be interval; B-soil off-balancesheet reads between correction zone; P-earth's surface; The front earth's surface of P0-sedimentation; Earth's surface after P1-sedimentation.

Embodiment

Below in conjunction with accompanying drawing 1, the present invention is further elaborated.Measurement mechanism of the present invention mainly comprises measurement body, measures body and the bottom anchor end 4 of the stable laccolite of sedimentation, the free end 5 of band downhole joint and transfer wire 6 is not occurred formed by soil table anchored end 1, the junction surface 3 between the strain sensing unit 2, strain sensing unit 2 of body of rod inside, implantation.

Below in conjunction with accompanying drawing 2, technical scheme of the present invention is described in detail:

Settlement measuring device of the present invention comprises two surveying ranges in the outer and soil body of the soil body, and be wherein online surveying range in the soil body between soil table anchored end 1 and bottom anchor end 4, soil is shown to be between native off-balancesheet reading correction zone between anchored end 1 and free end 5.

Comprise one or more groups strain sensing unit 2 in each surveying range respectively, the number of strain sensing unit is according to soil layer number and measure requirement formulation.Strain sensing unit 2 is connected by junction surface 3.Utilize in strain sensing distributed unit composite implant material muscle, composite material bar is set in ground, its bottom anchor end 4 anchors into the stable rock stratum that sedimentation does not occur, its soil table anchored end 1 shows anchoring with soil, its free end 5 draws data line 6, access data transmitting device 7, to realize measuring.

Install at settlement measuring device of the present invention and need to demarcate gauge length corresponding to each sensing unit, be i.e. interval A1, A2, A3, A in accompanying drawing 2 _n+1corresponding length L1, L2, L3, L _n+1.When after generation sedimentation, measure interval corresponding strain variation and the outer interval length variations of the soil body in the soil body.

As shown in Figure 3, the sedimentation and deformation for surveying range online in the soil body is compressive strain, and its actual measurement strain value is negative, take absolute value 1,2,3, ε _nsedimentation 1 in the soil body is calculated according to formula 1.

$\mathrm{\δ}1=\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\ϵ}}_i\×L_i$ Formula 1

As shown in Figure 3, by the body of rod, scale is identified for the native off-balancesheet sedimentation 2 of reading between correction zone of native off-balancesheet directly to read.

According to formula 2 conformity calculation total settlement.

δ=δ 1+ δ 2 formula 2

As shown in Figure 4, sensor of the present invention is laid on the line style bank protections such as the roadbed of highway and railway, and obtains the planar sedimentation distribution of a, b, c multiple spot.

Strain Distribution before sedimentation: $\left[\begin{array}{ccc}{\mathrm{\ϵ}}_{a1}& {\mathrm{\ϵ}}_{b1}& {\mathrm{\ϵ}}_{c1}\\ {\mathrm{\ϵ}}_{a2}& {\mathrm{\ϵ}}_{b2}& {\mathrm{\ϵ}}_{c2}\\ {\mathrm{\ϵ}}_{a3}& {\mathrm{\ϵ}}_{b3}& {\mathrm{\ϵ}}_{c3}\end{array}\right];$

Strain Distribution after sedimentation: $\left[\begin{array}{ccc}{{\mathrm{\ϵ}}_{a1}}^{,}& {{\mathrm{\ϵ}}_{b1}}^{,}& {{\mathrm{\ϵ}}_{c1}}^{,}\\ {{\mathrm{\ϵ}}_{a2}}^{,}& {{\mathrm{\ϵ}}_{b2}}^{,}& {{\mathrm{\ϵ}}_{c2}}^{,}\\ {{\mathrm{\ϵ}}_{a3}}^{,}& {{\mathrm{\ϵ}}_{b3}}^{,}& {{\mathrm{\ϵ}}_{c3}}^{,}\end{array}\right];$

Total settlement is integrated: $\left[\begin{array}{ccc}{\mathrm{\δ}}_{a1}& {\mathrm{\δ}}_{b1}& {\mathrm{\δ}}_{c1}\\ {\mathrm{\δ}}_{a2}& {\mathrm{\δ}}_{b2}& {\mathrm{\δ}}_{c2}\\ {\mathrm{\δ}}_{a3}& {\mathrm{\δ}}_{b3}& {\mathrm{\δ}}_{c3}\end{array}\right].$

Principle of work of the present invention is: the course of work of the present invention is as follows: in settlement measurement engineering, is embedded in by sedimentometer in different depth soil layer, must bury underground with stable rock stratum bottom it.First, by the long gauge length sensing unit with body of rod compatible deformation, measure settling amount in the soil body; Again by measuring the length of free end and soil table anchored end surveying range, measure the settling amount of native off-balancesheet; By integrating above two results, the total settlement of generation can be known.

As shown in Figure 5, sensor of the present invention is laid in each monitored area of traffic route, and by building different signal transmission networks according to kind of sensor, as types of fiber sensing can the wired optical fiber transmission network of component, the electronic sensors such as carbon fiber can build wireless signal transmission network.Then set up about horizontal direction distributed, and comprise all fronts monitoring network of longitudinal multiple spot.

Claims (5)

1. a distributed settlement measuring device, is characterized in that: comprise into the continuous fiber composite reinforcing of vertically squeezing into the soil body or basic internal of array distribution at institute's geodetic base, described continuous fiber composite reinforcing is by bottom anchor end, the soil layer sensing body of rod, soil table anchoring sheet and data line exit composition, the many group leaders gauge length strain sensing unit spliced in the longitudinal direction is comprised in described soil layer sensing body of rod inside, described data line exit is positioned at the upper end of the described soil layer sensing body of rod and is connected with described long gauge length strain sensing unit, the soil layer anchoring bolt with each soil consolidation is laid with outside gauge length strain sensing unit spliced position long described in two, described soil table anchoring sheet shows anchoring in native table position and soil, scale is had in the external mark of soil layer sensor bar.

2. distributed settlement measuring device according to claim 1, is characterized in that: described should long gauge length change sensing unit be point type electronics strain sensor, optical fiber or carbon fiber strain sensor.

3. distributed settlement measuring device according to claim 1, is characterized in that: the material of the described soil layer sensing body of rod is carbon fiber, glass fibre or basalt fibre.

4. adopt distributed sedimentation device described in claim 1 to measure a method for sedimentation, it is characterized in that, comprise following steps:

Step one, install and measure device: after monitoring point sets vertical shaft, insert and fix described measurement mechanism;

Step 2, measurement and record the strain initial value of online surveying range in the soil body, gauge length that each continuous fiber composite reinforcing section interval covers and native off-balancesheet read initial scale between correction zone,

The gauge length that wherein each continuous fiber composite reinforcing section interval covers is determined by following formula:

$L=\left[\begin{array}{ccccc}{l}_{11}& \mathrm{...}& l_{i1}& \mathrm{...}& l_{m1}\\ & & .& & \\ & & .& & \\ & & .& & \\ l_{1j}& \mathrm{...}& l_{ij}& \mathrm{...}& l_{mj}\\ & & .& & \\ & & .& & \\ & & .& & \\ l_{1n}& \mathrm{...}& l_{in}& \mathrm{...}& l_{mn}\end{array}\right],$

In formula, m is the on-line measurement interval monitoring point number covered in measurement range, and n is the sensing unit group number that in the soil body of each monitoring point, measurement mechanism comprises,

Wherein: in the described soil body, online surveying range is between bottom anchor portion to soil table anchor portion, it is between soil table anchor portion to free end that described native off-balancesheet reads between correction zone;

Step 3: after sedimentation and deformation, in measurement, in the step soil body, online surveying range internal strain changes, and according to each section of interval gauge length, calculates each interval corresponding compression deformation, and directly reads the scale changing value exposed in native off-balancesheet reading correction zone,

Wherein in the soil body, online surveying range internal strain change is determined by following formula:

${\mathrm{\ϵ}}_{(m,n)}=\left[\begin{array}{ccccc}{\mathrm{\ϵ}}_{11}& \mathrm{...}& {\mathrm{\ϵ}}_{i1}& \mathrm{...}& {\mathrm{\ϵ}}_{m1}\\ & & .& & \\ & & .& & \\ & & .& & \\ {\mathrm{\ϵ}}_{1j}& \mathrm{...}& {\mathrm{\ϵ}}_{ij}& \mathrm{...}& {\mathrm{\ϵ}}_{mj}\\ & & .& & \\ & & .& & \\ & & .& & \\ {\mathrm{\ϵ}}_{1n}& \mathrm{...}& {\mathrm{\ϵ}}_{in}& \mathrm{...}& {\mathrm{\ϵ}}_{mn}\end{array}\right],$

Wherein each interval corresponding compression deformation is determined by following formula:

in formula be the interior online measured value of the soil body of i-th monitoring point,

The native off-balancesheet corrected value that wherein each interval is read is determined by following formula:

${\mathrm{\δ}}^2=\left[\begin{array}{ccccc}{\mathrm{\δ}}_1^2& \mathrm{...}& {\mathrm{\δ}}_i^2& \mathrm{...}& {\mathrm{\δ}}_m^2\end{array}\right],$ In formula it is the native off-balancesheet corrected value of i-th monitoring point;

Step 4: in the soil body obtain upper step, online surveying range and native off-balancesheet read the distortion summation between correction zone, obtain bulk settling amount,

The total settlement that wherein each interval is integrated is determined by following formula:

δ in formula _iit is the total settlement of i-th monitoring point.

5. method according to claim 4, is characterized in that, the method for fixing described measurement mechanism in described step one is: utilize pressing method that resin bag pressure is entered silo bottom until stable rock stratum place; Rack resin bag by rotating described measurement body and be stirred to the complete consolidation of resin.