1. the utility model provides a monitoring devices of surrounding rock horizontal absolute displacement which characterized in that: the device comprises an inclinometry device arranged inside the surrounding rock and a surface displacement measurement device outside the surrounding rock;

the inclinometer comprises n cascaded biaxial inclinometers (5) arranged in the same inclinometer pipe (1), wherein each biaxial inclinometer (5) comprises an inclination angle sensor, a rigid connecting rod (3), a forward pulley block (6) and a lateral pulley block (7), and the forward pulley block (6) and the lateral pulley block (7) are respectively arranged at two ends of the rigid connecting rod (3) and are orthogonally arranged in space; the adjacent rigid connecting rods (3) are movably connected through universal joints (4); the tilt angle sensor is connected with an external data acquisition unit through a lead;

the inclinometer pipe (1) is arranged in a measuring hole in the surrounding rock and is fixed with the measuring hole into a whole;

the surface displacement measuring device comprises a total station (12) and a reflecting sticker (11) arranged on the exposed top (10) of the inclinometer pipe (1), wherein the total station (12) records the displacement of the reflecting sticker (11);

the inclination measuring device acquires inclination parameters at different depths inside the measuring hole, and the inclination parameters are combined with displacement parameters at the hole opening of the measuring hole acquired by the earth surface displacement measuring device to calculate and obtain an absolute displacement value of the surrounding rock in the horizontal direction.

2. The device for monitoring the horizontal absolute displacement of the surrounding rock according to claim 1, wherein: the forward pulley block (6) and the lateral pulley block (7) both comprise a connecting rod (9) and two pulleys (8) arranged at two ends of the connecting rod (9).

3. The device for monitoring the horizontal absolute displacement of the surrounding rock according to claim 2, wherein: the middle part of the rigid connecting rod (3) is provided with a through hole, and the connecting rod (9) passes through the through hole.

4. The device for monitoring the horizontal absolute displacement of the surrounding rock according to claim 2, wherein: the inner wall of the inclinometer pipe (1) is provided with a cross notch for limiting the deflection of the pulley along the axis direction of the inclinometer pipe.

5. The device for monitoring the horizontal absolute displacement of the surrounding rock according to claim 1, wherein: the positive pulley block (6) is consistent with the x-axis direction of the inclination angle sensor of the double-axis inclinometer (5), and the lateral pulley block (7) is consistent with the y-axis direction of the inclination angle sensor of the double-axis inclinometer (5).

6. The device for monitoring the horizontal absolute displacement of the surrounding rock according to claim 1, wherein: n is 2 to 5.

7. A method for monitoring horizontal absolute displacement of surrounding rock is characterized by comprising the following steps:

【1】 Establishing a device for monitoring the horizontal absolute displacement of the surrounding rock according to any one of claims 1 to 6;

【2】 Total station instrument obtains horizontal displacement delta x of reflection of light subsides₀And Δ y₀The displacement value at the hole opening of the measuring hole is obtained;

【3】 Calculating the horizontal displacement of any two-axis inclinometer:

assuming that the upper position of a rigid connecting rod in the biaxial inclinometer is unchanged, and the lower position of the rigid connecting rod moves; the length of the rigid connecting rod is l_iThe positive x displacement length of the lower part of the rigid connecting rod is Deltax_iLateral y displacement length of Δ y_iCalculating the horizontal displacement distance as follows:

Δx_i＝l_i×cosθ×tanα

Δy_i＝l_i×cosθ×tanβ

wherein theta is the integral offset angle of the rigid connecting rodAlpha is a positive x offset angle measured by a biaxial inclinometer, and beta is a lateral y offset angle;

【4】 Superposing the displacement of n sections of rigid connecting rods in the rock stratum and the displacement value at the hole opening of the measuring hole to obtain:

wherein Δ x_nAnd Δ y_nThe horizontal absolute displacement values of the surrounding rock in the x-axis direction and the y-axis direction are respectively.

Background

China has countries belonging to mountains, the mountain area occupies more than 2/3 of the territory, and a large number of mountain tunnels and urban subways are inevitably constructed in the process of constructing the high-quality three-dimensional traffic network. In order to guarantee tunnel construction safety, prevent that tunnel unstability from destroying, guarantee traffic safety, tunnel engineering's control project is indispensable.

The internal displacement of the tunnel surrounding rock can directly reflect the stress and deformation state of the surrounding rock, and the safety of the whole tunnel excavation and operation process is monitored. Meanwhile, surrounding rock deformation caused by tunnel excavation is not single radial convergence, but deformation in the three-dimensional direction is caused, when an excavation section is close to, the surrounding rock can have certain advanced displacement, and great vacancy exists in the current research on the advanced displacement and displacement direction of the surrounding rock in China, so that a monitoring device and a calculation method for the horizontal absolute displacement of the surrounding rock are urgently to be constructed, and the horizontal displacement and the displacement angle of the surrounding rock in the tunnel are monitored.

Currently, the commonly used measuring devices mainly include an inclinometer, a single-point/multi-point displacement meter, a flexible inclinometer and the like, but the following problems exist to different degrees: the inclinometer and the displacement meter cannot acquire the absolute displacement of the surrounding rock and the horizontal displacement of the double axes, and the test error is large; the flexible inclinometer has high manufacturing cost and limited measuring range and length.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a device and a method for monitoring the horizontal absolute displacement of the surrounding rock, which utilize a double-shaft inclinometer in a surrounding rock survey hole and an external total station to respectively monitor the displacement parameters of multiple sections in the surrounding rock and the displacement parameters of the survey hole, and further calculate to obtain the horizontal absolute displacement value of the surrounding rock.

The technical scheme of the invention is as follows:

a monitoring device for horizontal absolute displacement of surrounding rocks comprises an inclination measuring device arranged inside the surrounding rocks and an earth surface displacement measuring device outside the surrounding rocks;

the inclination measuring device comprises n cascaded double-shaft inclinometers arranged in the same inclination measuring pipe, each double-shaft inclinometer comprises an inclination angle sensor, a rigid connecting rod, a forward pulley block and a lateral pulley block, and the forward pulley block and the lateral pulley block are respectively arranged at two ends of the rigid connecting rod and are orthogonally arranged in space; the adjacent rigid connecting rods are movably connected through universal joints; the tilt angle sensor is connected with an external data acquisition unit through a lead;

the inclinometer pipe is arranged in the measuring hole in the surrounding rock and is fixed with the measuring hole into a whole;

the surface displacement measuring device comprises a total station and a reflecting sticker arranged on the exposed top of the inclinometer pipe, and the total station records the displacement of the reflecting sticker;

the inclination measuring device acquires inclination parameters at different depths inside the measuring hole, and the inclination parameters are combined with displacement parameters at the hole opening of the measuring hole acquired by the earth surface displacement measuring device to calculate and obtain an absolute displacement value of the surrounding rock in the horizontal direction.

In the device for monitoring the horizontal absolute displacement of the surrounding rock, the forward pulley block and the lateral pulley block respectively comprise a connecting rod and two pulleys arranged at two ends of the connecting rod.

In the monitoring device for the horizontal absolute displacement of the surrounding rock, the middle part of the rigid connecting rod is provided with a through hole, and the connecting rod penetrates through the through hole.

Among the above-mentioned monitoring devices of wall rock horizontal absolute displacement, the deviational survey pipe be the stereoplasm PVC material, add the reality through fine sand or concrete between survey hole and the deviational survey pipe to solid as an organic whole, arouse the different positions of deviational survey pipe when the wall rock takes place to warp and take place the displacement.

In the monitoring device for the horizontal absolute displacement of the surrounding rock, the inner wall of the inclinometer pipe is provided with a cross notch for limiting the deflection of the pulley along the axis direction of the inclinometer pipe.

In the monitoring device for the horizontal absolute displacement of the surrounding rock, the direction of the forward pulley block is consistent with the direction of the x axis of the inclination angle sensor of the double-axis inclinometer, and the direction of the lateral pulley block is consistent with the direction of the y axis of the inclination angle sensor of the double-axis inclinometer.

In the monitoring device for the horizontal absolute displacement of the surrounding rock, n is 2-5.

A method for monitoring horizontal absolute displacement of surrounding rock comprises the following steps:

【1】 Establishing a monitoring device for the horizontal absolute displacement of the surrounding rock;

【2】 Total station instrument obtains horizontal displacement delta x of reflection of light subsides₀And Δ y₀The displacement value at the hole opening of the measuring hole is obtained;

【3】 Calculating the horizontal displacement of any two-axis inclinometer:

assuming that the upper position of a rigid connecting rod in the biaxial inclinometer is unchanged, and the lower position of the rigid connecting rod moves; the length of the rigid connecting rod is l_iThe positive x displacement length of the lower part of the rigid connecting rod is Deltax_iLateral y displacement length of Δ y_iCalculating the horizontal displacement distance as follows:

Δx_i＝l_i×cosθ×tanα

Δy_i＝l_i×cosθ×tanβ

wherein theta is the integral offset angle of the rigid connecting rod,alpha is a positive x offset angle measured by a biaxial inclinometer, and beta is a lateral y offset angle;

【4】 Superposing the displacement of n sections of rigid connecting rods in the rock stratum and the displacement value at the hole opening of the measuring hole to obtain:

wherein Δ x_nAnd Δ y_nThe horizontal absolute displacement values of the surrounding rock in the x-axis direction and the y-axis direction are respectively.

The invention has the following beneficial technical effects:

1. the monitoring device for the horizontal absolute displacement of the surrounding rock respectively monitors the displacement parameters of the internal displacement of the surrounding rock and the displacement parameters of the measuring hole by using the double-shaft inclinometer and the external total station in the measuring hole of the surrounding rock, combines the monitoring of the relative displacement of the measuring point of the traditional inclinometer and further calculates to obtain the horizontal absolute displacement value of the surrounding rock; compared with the traditional inclinometer, the method has the advantages that the relative displacement parameters between the orifice and the measuring point are obtained, and the defects that the traditional displacement meter cannot monitor the displacement direction and correct the displacement are overcome; simultaneously, compared with a flexible inclinometer, the device has simple structure and lower cost.

2. The double-shaft inclinometer adopts the bidirectional pulley, the cross notch in the inclinometer and the double-shaft inclinometer to position and monitor the direction, thereby acquiring the horizontal double-shaft displacement, avoiding the defects of the unidirectional pulley and the relative displacement of the traditional inclinometer, and having higher test precision and smaller error; meanwhile, a plurality of biaxial inclinometers are movably connected with the universal joints 4 through rigid connecting rods and can be extended into deeper rock mass, and segmental displacement monitoring at different positions in the measuring hole is realized.

3. The rigid connecting rod in the biaxial inclinometer can be designed according to the actual engineering condition, so that the test requirements of different projects are met; meanwhile, the pulley is located at the end of the connecting rod, the double-shaft inclinometer is located in the middle of the connecting rod, segmented monitoring is achieved, and the pulley is compared with a short-distance pulley of a traditional inclinometer, so that the test precision is improved.

Drawings

Fig. 1 is an overall composition schematic diagram of the tunnel surrounding rock horizontal absolute displacement monitoring device of the invention.

FIG. 2 is a structural diagram of the internal inclination measuring device of the surrounding rock according to the present invention.

Fig. 3 is a schematic view of a partial structure of the surrounding rock internal inclination measuring device of the present invention.

Fig. 4 is a schematic diagram of the layout of the bidirectional pulley block of the inclinometer.

Fig. 5 is a schematic view of a pulley block structure of the present invention.

FIG. 6 is a schematic diagram of the calculation of the horizontal displacement measured by a biaxial inclinometer according to the present invention.

In the figure, 1-inclinometer pipe, 2-pipe bottom, 3-rigid connecting rod, 4-universal joint, 5-biaxial inclinometer, 6-forward pulley block, 6-1-rod top forward pulley block, 6-2-rod bottom forward pulley block, 7-lateral pulley block, 7-1-rod top lateral pulley block, 7-2-rod bottom lateral pulley block, 8-pulley, 9-connecting rod, 10-exposed top, 11-reflective sticker, and 12-total station.

Detailed Description

As shown in fig. 1-5, the monitoring device for the horizontal absolute displacement of the surrounding rock comprises an inclinometry device arranged inside the surrounding rock and an earth surface displacement measuring device arranged outside the surrounding rock;

the inclinometer comprises n cascaded biaxial inclinometers 5 arranged in the same inclinometer pipe 1, wherein each biaxial inclinometer 5 comprises an inclination angle sensor, a rigid connecting rod 3, a forward pulley block 6 and a lateral pulley block 7, and the forward pulley block 6 and the lateral pulley block 7 are respectively arranged at two ends of the rigid connecting rod 3 and are orthogonally arranged in space; the adjacent rigid connecting rods 3 are movably connected through universal joints 4; the tilt angle sensor is connected with an external data acquisition unit through a lead; the inclinometer 1 is made of hard PVC material and is arranged in a measuring hole in the surrounding rock, and the measuring hole and the inclinometer 1 are compacted by fine sand or concrete and are fixed into a whole; the length of the rigid connecting rod 3 can be changed according to the design requirement before leaving the factory, and the pulley block is positioned at the end part of the rigid connecting rod 3. A rigid connecting rod represents a test section that can be measured to determine the amount of horizontal displacement between the end pulley and the tail pulley.

When the surrounding rock is displaced, different positions of the inclinometer pipe are displaced to different degrees, so that the pulley and the double-shaft inclinometer are caused to be displaced to obtain a double-shaft angle variation, and the horizontal displacement variation is obtained by converting the length of the rigid connecting rod and the angle size.

The surface displacement measuring device comprises a total station 12 and a reflective sticker 11 arranged on the exposed top 10 of the inclinometer 1, wherein the total station 12 records the displacement of the reflective sticker 11, and the three-dimensional coordinate variation of the orifice can be acquired through monitoring.

The inclination measuring device acquires inclination parameters at different depths inside the measuring hole, and the inclination parameters are combined with displacement parameters at the position of the hole of the measuring hole acquired by the earth surface displacement measuring device, and the absolute displacement value of the surrounding rock in the horizontal direction is calculated. The device is buried through a vertical earth surface measuring hole, and the measuring depth and the measuring length can be changed according to actual conditions; according to the measured biaxial angle offset and the length of the measuring rod, converting to obtain a horizontal displacement; meanwhile, the horizontal displacement of the measuring hole is obtained through monitoring of the light reflecting sticker 11, and then the absolute displacement of the tunnel surrounding rock in the horizontal direction is obtained.

In fig. 2 and 3, the forward pulley block 6 and the lateral pulley block 7 are respectively arranged at two ends of the rigid connecting rod 3 and are orthogonally arranged in space; wherein 6-1 is a measuring bar top forward pulley block, 6-2 is a measuring bar bottom forward pulley block, 7-1 is a measuring bar top lateral pulley block, and 7-2 is a measuring bar bottom lateral pulley block.

As shown in fig. 4 and 5, each of the forward pulley block 6 and the lateral pulley block 7 includes a connecting rod 9 and two pulleys 8 disposed at two ends of the connecting rod 9, a through hole is disposed in the middle of the rigid connecting rod 3, and the connecting rod 9 passes through the through hole. The inner wall of the inclinometer 1 is provided with a cross-shaped notch groove for limiting the deflection of the pulley along the axis direction of the inclinometer. The groove width of the cross-shaped notch groove is matched with the thickness of the pulley, and the limiting effect of the through hole in the middle of the rigid connecting rod 3 can ensure that the forward pulley block 6 and the lateral pulley block 7 can move according to the set direction, so that the measuring direction of the biaxial inclinometer 5 is positioned.

When the method is used, the earth surface to be measured is drilled, the inclinometer pipe 1 with the pipe bottom 2 is placed in the hole after the hole is formed, the direction of the cross groove is adjusted, and then sandy soil or slurry is adopted to fill the gap between the hole wall and the inclinometer pipe 1, so that the pore wall and the inclinometer pipe are tightly bonded and can deform together.

The length of the rigid connecting rods 3 needs to be designed before the biaxial inclinometer leaves a factory, prefabrication is completed in advance, each section of rigid connecting rods 3 are connected through universal joints 4, and the forward direction and the lateral direction of the biaxial inclinometer 5 need to be consistent with the directions of the forward pulley block 6 and the lateral pulley block 7 respectively. The monitoring device with designed length and distance measurement is placed into the inclinometer tube 1, and the forward pulley block 6 and the lateral pulley block 7 are aligned with the cross slot in the inclinometer tube 1. The double-shaft inclinometer 5 is internally provided with a lead with corresponding length, and can be communicated to the earth surface, so that the external acquisition instrument can acquire data conveniently. After the installation is finished, the ground hole is sealed and leveled by concrete or mortar, and the light reflecting paste 11 is installed.

During measurement, the total station 12 is adopted to monitor the reflective sticker 11 for a long time to obtain three-dimensional coordinate data, and the displacement variation is converted into displacement variation components of the double-shaft inclinometer 5 in the forward direction and the lateral direction, so that the horizontal displacement delta x at the hole is obtained₀And Δ y₀. Monitoring a double-shaft inclinometer 5 in the inclinometer 1 by adopting a collecting instrument to obtain the angle variation of the double-shaft inclinometer 5, and calculating the bottom horizontal displacement delta x of each section of rigid connecting rod 3 by a formula_iAnd Δ y_i. The horizontal displacement of the orifice and the horizontal displacement of the bottom of the rigid connecting rod are sequentially superposed to obtain the horizontal absolute displacement of the surrounding rock, namely

The invention discloses a method for monitoring and calculating horizontal absolute displacement of surrounding rock, which comprises the following steps:

【1】 Drilling a measuring hole and embedding the monitoring device, and filling the side wall of the inclinometer pipe with materials such as fine sand or concrete to tightly attach the inclinometer pipe to the rock wall;

【2】 After the instrument is installed, the reflective patch is installed at the orifice and is monitored for a long time to obtain the horizontal displacement delta x of the reflective patch₀And Δ y₀；

【3】 And (3) calculating the horizontal displacement of the rock stratum:

the calculation principle is shown in fig. 6, wherein the positive pulley block 6 is consistent with the x-axis direction of the biaxial inclinometer 5, and the lateral pulley block 7 is consistent with the y-axis direction of the biaxial inclinometer 5. In the figure, |_iFor measuring the length of the measuring rod, theta is the integral offset angle of the measuring rod, alpha is the positive x offset angle of the measuring rod, and delta x_iIs the lateral x displacement length of the lower part of the measuring rod, beta is the lateral y offset angle of the measuring rod, delta y_iIs the lateral y displacement length of the lower part of the measuring rod.

(3.1) take one of them section rigid link of monitoring devices as an example and calculate, supposing that rigid link upper portion position is unchangeable, the lower part position takes place to remove, and biax inclinometer measures forward x skew angle and is alpha, measures side direction y skew angle and is beta, calculates and obtains the whole skew angle theta of rigid link and be:

(3.2) rigid connecting rod length of l_iThe positive x displacement length of the lower part of the rigid connecting rod is Deltax_iLateral y displacement length of Δ y_iCalculating the horizontal displacement distance as follows:

Δx_i＝l_i×cosθ×tanα

Δy_i＝l_i×cosθ×tanβ

(3.3) according to the formula (3.2), the displacement of n sections of rigid connecting rods in the rock stratum is superposed, and the obtained horizontal displacement in the rock stratum is as follows: