CN105222714A - A kind of method improving total powerstation Opposite side survey tunnel clearance convergence precision - Google Patents

Abstract

The present invention relates to a kind of method improving tunnel clearance convergence clubs precision, be specifically related to a kind of method improving total powerstation Opposite side survey tunnel clearance convergence precision.It adopts total powerstation opposite side to measure method, and based on two tracks, three lanes and four lane road tunnel actual profile size, and on-the-spot clearance convergence measures actual conditions, by selecting rational total powerstation decorating position, improves measurement accuracy.The method step that the present invention adopts is: first, be laid in the maximum excavatoin line place of monitoring section, and protect, avoid monitoring point to be affected destruction in constructing tunnel by symmetrical for two monitoring points; Then, select rational position erection total powerstation, finally, utilize total powerstation Opposite side survey function to complete measurement digital independent, and after having measured each time, recover measuring point protection.

Description

A kind of method improving total powerstation Opposite side survey tunnel clearance convergence precision

One, technical field:

The present invention relates to a kind of method improving tunnel clearance convergence clubs precision, be specifically related to a kind of method improving total powerstation Opposite side survey tunnel clearance convergence precision.

Two, background technology:

Clearance convergence be tunnel monitoring measurement must survey project, be tunnel surrounding stress state change the most directly reflect.Current vcehicular tunnel clearance convergence mainly adopts convergence gauge to measure, but this method for measurement efficiency is low, and normal and site operation disturbs mutually.During as stayed Core Soil Ring Cutting in employing arch, tunnel, before Core Soil does not excavate, due to the stop of Core Soil, convergence gauge cannot launch measurement along the horizontal survey line opposite side of section, cause the delayed of distortion preliminary survey, cause a part or even most in early stage tunnel wall rock deformation information loss, therefore monitoring result truly can not intactly reflect tunnel wall rock deformation situation.Equally, also there is certain obstruction to normally carrying out of constructing tunnel in the carrying out that on-the-spot convergence gauge contact measures, affects Tunnel Construction Schedule.Increasing along with current big cross section long tunnel, construction method is changeable, and traditional convergence gauge contact method for measurement cannot meet modern major long tunnel construction requirement fast and safely.Therefore, a kind of quick, easy, by the little non-contact measurement method of tunnel construction infection---total powerstation Opposite side survey method, be incorporated into gradually tunnel clearance convergence monitoring measurement in.But the measurement accuracy research at present about this measuring method is relatively less, there is no comparatively clear and definite conclusion as the foundation of in-site measurement, improve measuring accuracy.

Three, summary of the invention:

In order to solve the weak point in above-mentioned background technology, the invention provides a kind of method improving total powerstation Opposite side survey tunnel clearance convergence precision, it adopts total powerstation opposite side to measure method, based on two tracks, three lanes and four lane road tunnel actual profile size, and on-the-spot clearance convergence measures actual conditions, by selecting rational total powerstation decorating position, improve measurement accuracy.

For achieving the above object, the technical solution used in the present invention is: a kind of method improving total powerstation Opposite side survey tunnel clearance convergence precision, is characterized in that: described method step is:

First, be laid in the maximum excavatoin line place of monitoring section by symmetrical for two monitoring points, and protect, avoid monitoring point to be affected destruction in constructing tunnel;

Then, rational position erection total powerstation is selected:

Two lane vural roads tunnel, is erected at apart from tunnel monitoring section 40 ~ 60m by total powerstation, within the scope of distance tunnel center line 5.25m;

Three-Lane Highway Tunnel, is erected at apart from tunnel monitoring section 40 ~ 50m, within tunnel center line 2.13m scope by total powerstation; Or total powerstation is erected at apart from monitoring section 50 ~ 70m, within tunnel center line 6.38m scope;

Four lane road tunnel, is erected at apart from monitoring section 50 ~ 60m, within tunnel center line 2.63m scope by total powerstation; Or total powerstation is erected at apart from monitoring section 60 ~ 70m, within tunnel center line 5.25m scope;

When meeting above condition, if field condition allows, total powerstation is erected near tunnel centerline as far as possible;

Finally, utilize total powerstation Opposite side survey function to complete measurement digital independent, and after having measured each time, recover measuring point protection.So, respectively the clearance convergence metric data of construction different phase and initial measurement are subtracted each other, calculate monitoring section clearance convergence result.

Compared with prior art, the advantage that the present invention has and effect as follows: the method, mainly from total powerstation decorating position, quantizes optimal location parameter, visual result, easily performs; Sets forth corresponding total powerstation optimal location parameter for two tracks, three lanes, four lane road tunnel, result is comprehensive, is more conducive to Fruits popularize; The method is strictly according to Opposite side survey principle and law of propagation of errors, and simultaneously in conjunction with on-the-spot tunnel clearance convergence clubs actual conditions, fiduciary level is high.

Four, accompanying drawing illustrates:

Fig. 1 is total powerstation Opposite side survey tunnel clearance convergence principle figure;

Fig. 2 calculates schematic diagram for measuring plane projection;

Fig. 3 is tunnel clearance convergence survey station location arrangements figure;

Fig. 4 is that reflection diaphragm is pasted;

Fig. 5 is measuring point protection;

Fig. 6 is YK110+878 section maximum excavatoin line convergence tense curve;

Fig. 7 is YK110+870 section maximum excavatoin line convergence tense curve;

Fig. 8 is YK110+861 section maximum excavatoin line horizontal convergence tense curve.

Five, embodiment:

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail:

First, burying underground and protecting of monitoring section measuring point is carried out.

In tunnel, wall symmetry in maximum excavatoin line left and right lays two monitoring points, P, A namely shown in Fig. 12 point.When measuring point is buried underground, first using pre-processed steel plate as reflection diaphragm base, be welded on P, A 2 correspondence positions on face the one Pin shaped steel arch.Then, reflection diaphragm is pasted onto on the steel plate fixedly completed, and tries one's best guarantee two reflection diaphragm central spot on same level line.Before sprayed concrete, the object such as polybag or geotextile need be wrapped on measuring point and be protected, avoid reflection diaphragm contaminated, destroy.After sprayed concrete operation completes, untie protection object, carry out the reading of initial reading immediately.Initial measurement and afterwards after measurement completes each time, measuring point protection must be recovered in time, in order to avoid Tunnel during Construction reflection diaphragm surface is contaminated, affect the accuracy of measurement data.In addition, in whole observation process, the co-ordination with relevant departments should be strengthened, avoid causing the position skew of measuring point because of constructing tunnel or destroying.

Then, set up total powerstation Opposite side survey tunnel clearance convergence precision computation model, and analyze.

General measure precision is by measuring medial error evaluation.Can be obtained by Fig. 1, the discrepancy in elevation h of P, A point-to-point transmission _pA, level interval D _pAwith oblique distance S _pAcomputing formula:

h _PA＝h _P-h _A＝S _Psinα _P-S _Asinα _A(1)

$D_{PA}=\sqrt{{S_P}^2{\cos }^2{\mathrm{\α}}_P+{S_A}^2{\cos }^2{\mathrm{\α}}_A-2S_P{S}_A{\mathrm{cos\α}}_P{\mathrm{cos\α}}_{A}cos\mathrm{\β}}---\left(2\right)$

$S_{PA}=\sqrt{{h_{PA}}^2+{D_{PA}}^2}---\left(3\right)$

Wherein, S _p, S _abe respectively OP, OA oblique distance, α _p, α _abe respectively OP, OA and measure vertical angle, β is horizontal angle between OP, OA.

Do not consider the impact of earth curvature and Atmosphere Refraction, total differential carried out to formula (3), and according to law of propagation of errors, obtain tunnel clearance convergence medial error computing formula:

$\begin{array}{c}{m}_{S_{PA}}^2=\frac{1}{S_{PA}^2}\{{\[-h_{PA}{\mathrm{tg\α}}_P+(D_P-D_A\cos \mathrm{\β})\]}^2{\cos }^2{\mathrm{\α}}_P{m}_{S_P}^2+\\ {\[h_{PA}{\mathrm{tg\α}}_A+(D_A-D_P\cos \mathrm{\β})\]}^2{\cos }^2{\mathrm{\α}}_A{m}_{S_A}^2+\\ \frac{1}{{\mathrm{\ρ}}^2}{\[-h_{PA}{\mathrm{ctg\α}}_P-(D_P-D_A\cos \mathrm{\β})\]}^2{S}_P^2{\sin }^2{\mathrm{\α}}_P{m}_{{\mathrm{\α}}_P}^2+\\ \frac{1}{{\mathrm{\ρ}}^2}{\[h_{PA}{\mathrm{ctg\α}}_A-(D_A-D_P\cos \mathrm{\β})\]}^2{S}_A^2{\sin }^2{\mathrm{\α}}_A{m}_{{\mathrm{\α}}_A}^2+\\ \frac{1}{{\mathrm{\ρ}}^2}{\left(D_P{D}_A\sin \mathrm{\β}\right)}^2{m}_{\mathrm{\β}}^2\}\end{array}---\left(4\right)$

In formula, ρ=206265 ", and m _βbe respectively S _p, S _a, α _p, α _awith the measurement medial error of β, D _p=S _pcos α _p, D _a=S _acos α _a, D _p, D _abe respectively OP and OA horizontal range.

According to D in Fig. 2 total powerstation Opposite side survey tunnel clearance convergence horizontal projection _p, D _awith D _pAbetween trigonometric function relation, formula (4) is transformed, and supposes D _pA=S _pAand mean square error of angle observation $m_{a_P}=m_{a_A}=m_a,$ Obtain:

$\begin{array}{c}{m}_{S_{PA}}^2={\cos }^2{\mathrm{\β}}_P({\cos }^2{\mathrm{\α}}_P{m}_{S_P}^2+\frac{1}{{\mathrm{\ρ}}^2}{S}_P^2{\sin }^2{\mathrm{\α}}_P{m}_{\mathrm{\α}}^2)+\\ {\cos }^2{\mathrm{\β}}_A({\cos }^2{\mathrm{\α}}_A{m}_{S_A}^2+\frac{1}{{\mathrm{\ρ}}^2}{S}_A^2{\sin }^2{\mathrm{\α}}_A{m}_{\mathrm{\α}}^2)\\ \frac{1}{{\mathrm{\ρ}}^2}{\left(\frac{D_{PA}}{{\mathrm{ctg\β}}_P+{\mathrm{ctg\β}}_A}\right)}^2{m}_{\mathrm{\β}}^2\end{array}---\left(5\right)$

Based on this, measure actual conditions in conjunction with on-the-spot clearance convergence, clearance convergence measuring accuracy during computational analysis different spans tunnel total powerstation difference decorating position.

Secondly, the reasonable decorating position of total powerstation is selected.

According to different spans tunnel Opposite side survey clearance convergence precision analysis result, select rational total powerstation decorating position, specifically as shown in table 1.In this position range, if field condition allows, make total powerstation decorating position near tunnel center line as far as possible.

Finally, utilize total powerstation Opposite side survey function to complete measurement digital independent, calculate the clearance convergence result of monitoring section relative to original bulk measured value.

After total powerstation has set up, the Opposite side survey function selecting instrument to carry, the reflection diaphragm central point of aiming point P and some A, just directly can read P, A 2 oblique distance S in screen respectively _pA.In essence, drawing of this value utilizes total powerstation self plug-in, by directly measuring oblique distance, the vertical angle between total powerstation center and measuring point, and the horizontal angle between two measuring points, calculate by formula (1) ~ (3).After having measured each time, must the protection of Restoration monitoring point.So, measure according to construction different phase the S obtained _pAvalue, subtracts each other itself and original bulk measured value respectively, calculates tunnel monitoring section clearance convergence result.

Embodiment:

Measure for the maximum excavatoin line horizontal convergence of Shenmu County of Shaanxi Province to Fugu highway big cross section three lanes Highway Tunnel in Loess, describe in detail.

When measuring point is buried underground, first using pre-processed steel plate as reflection diaphragm base, be welded on P, A 2 correspondence positions (as shown in Figure 1) on face the one Pin shaped steel arch after tunnel excavation.P, A point lays respectively at the maximum excavatoin line place of monitoring section left and right sides.Then, reflection diaphragm is pasted onto on the steel plate fixedly completed, as shown in Figure 4.When reflection diaphragm is pasted, should ensure that two reflection diaphragm central spot are on same level line as far as possible.After reflection diaphragm has been pasted, geotextile be wrapped on measuring point, blend compounds band carries out winding and ties up (as shown in Figure 5), is protected, avoid reflection diaphragm contaminated when sprayed concrete afterwards, destroy.

According to the actual profile size of relied on big cross section Three-Lane Highway Tunnel, get section maximum excavatoin line horizontal convergence survey line length S _pA(assuming that S _pA=D _pA) be 17m, be 2m with the vertical height on road surface.Because total powerstation antenna height is generally 1.2 ~ 1.5m, consider the impact of vertical angle, getting total powerstation apart from the horizontal survey line vertical height of maximum excavatoin line is 1m.In measuring process, be semiobservation angle value because opposite side measures angle measurement β, therefore get m _β=m _half-angle=± 2 ".Total station survey precision is " m _s=2+2ppm, m _α=1 " ".Based on more than, by total powerstation Opposite side survey accuracy computation model (formula 5), calculate different total powerstation position and the horizontal survey line of the maximum excavatoin line of lower section is set measures medial error.Because P, A 2 is symmetrical about tunnel center line, therefore only consider that total powerstation being laid in center line side, tunnel carries out accuracy computation analysis, as shown in Figure 3.Wherein, h is the horizontal range of total powerstation decorating position apart from measuring section.Last result of calculation is as shown in table 2.

Based on the result of calculation of table 2, draw: when the maximum excavatoin line horizontal convergence of Three-Lane Highway Tunnel measures, total powerstation is erected at apart from tunnel monitoring section 40 ~ 50m, within tunnel center line 2.125m scope; Or total powerstation is erected at apart from tunnel monitoring section 50 ~ 70m, within tunnel center line 6.375m scope, measure medial error and arrange lower relative to other position, all below 0.70, and total powerstation is the closer to tunnel center line, and measuring accuracy is higher.

Therefore; after construction of shotcrete completes; take off measuring point protection object in time; total powerstation erection is completed (at the scene in conditions permit situation by table 1 requirement; make total powerstation decorating position near tunnel center line) as far as possible; read metric data, as the initial reading of tunnel clearance convergence monitoring.During measurement, first select the Opposite side survey function that total powerstation carries, then distinguish the reflection diaphragm central point of aiming point P and some A, so just on total powerstation screen, directly can read PA oblique distance S _pA, complete initial measurement.

At initial measurement and after having measured each time afterwards, recover the protection of measuring point all in time, avoid reflection diaphragm surface in constructing tunnel contaminated, affect the accuracy of measurement data.Meanwhile, in whole observation process, strengthen the co-ordination with relevant departments, avoid causing the position skew of measuring point because of constructing tunnel or destroying.

So, according to the S that the measurement of construction different phase obtains _pAvalue, subtracts each other itself and initial measurement respectively, calculates the horizontal convergence of monitoring section maximum excavatoin line in tunnel relative to original bulk measured value.Monitoring result as figure 6 ?shown in 8.

From figure 6 ?8, this Opposite side survey method measurement result precision compared with measurement of coordinates is higher, more stable; Measurement result Changing Pattern and convergence gauge are measured basically identical.Therefore, the method not only compensate for the shortcoming that convergence gauge measures clearance convergence shortage of data in early stage, and ensure that measuring accuracy well, and measurement result is desirable.

Table 1 liang track, three lanes and four lane road tunnel total powerstation decorating position are arranged

The maximum excavatoin line of table 2 Three-Lane Highway Tunnel total powerstation change in location horizontal survey line Opposite side survey medial error

Claims (1)

1. improve a method for total powerstation Opposite side survey tunnel clearance convergence precision, it is characterized in that: described method step is:

First, be laid in the maximum excavatoin line place of monitoring section by symmetrical for two monitoring points, and protect, avoid monitoring point to be affected destruction in constructing tunnel;

Then, rational position erection total powerstation is selected:

Two lane vural roads tunnel, is erected at apart from tunnel monitoring section 40 ~ 60m by total powerstation, within the scope of distance tunnel center line 5.25m;

Three-Lane Highway Tunnel, is erected at apart from tunnel monitoring section 40 ~ 50m, within tunnel center line 2.13m scope by total powerstation; Or total powerstation is erected at apart from monitoring section 50 ~ 70m, within tunnel center line 6.38m scope;

Four lane road tunnel, is erected at apart from monitoring section 50 ~ 60m, within tunnel center line 2.63m scope by total powerstation; Or total powerstation is erected at apart from monitoring section 60 ~ 70m, within tunnel center line 5.25m scope;

When meeting above condition, if field condition allows, total powerstation is erected near tunnel centerline as far as possible;

Finally, utilize total powerstation Opposite side survey function to complete measurement digital independent, and after having measured each time, recover measuring point protection.So, respectively the clearance convergence metric data of construction different phase and initial measurement are subtracted each other, calculate monitoring section clearance convergence result.