CN111322940A - Tunnel face deep soil horizontal displacement monitoring device and method - Google Patents

Abstract

The invention relates to a device and a method for monitoring horizontal displacement of a deep soil body on a tunnel face, wherein the device for monitoring horizontal displacement is assembled as follows: a displacement sensor is fixed on the inner wall of one end of each PVC pipe, the PVC pipes are connected through rubber rings, and each displacement sensor draws a steel wire and is tensioned and fixed to the tail end of the last PVC pipe; drilling each monitoring point on the tunnel face to form a plurality of monitoring holes; inserting the assembled horizontal displacement monitoring device into the monitoring hole; filling the gap between the monitoring hole and the PVC pipe; and electrifying the horizontal displacement monitoring device, and monitoring the extrusion deformation of the core soil with the tunnel face ahead in real time. The monitoring data obtained by the method can reflect the extrusion deformation of the core soil in front of the tunnel face to the maximum extent, and provide a basis for evaluating the stability of the tunnel face excavated from the full section of the tunnel.

Description

A device and method for monitoring horizontal displacement of soil in deep part of tunnel face

technical field

The invention relates to the technical field of tunnel engineering, in particular to a device and method for monitoring the horizontal displacement of soil in the deep part of a tunnel face.

Background technique

Affected by the tunnel construction method, the current monitoring of tunnel construction mainly focuses on conventional monitoring items such as surface settlement deformation, tunnel vault settlement, and convergence deformation of surrounding caverns. With the continuous upgrade of the level of mechanization in tunnel construction, the construction method of urban shallow-buried tunnels has changed from the step method to the full-section method, and the core soil will be excavated.

The research shows that the disturbance of tunnel excavation on the surrounding rock is three-dimensional. In addition to affecting the radial surrounding rock of the tunnel face, the surrounding rock in front of the tunnel axial face will also have a greater impact. The tunnel area is at least 30 The % convergence deformation occurs before the tunnel face arrives. The surrounding rock in front of the tunnel face will deform first, and then the tunnel wall will converge. Therefore, the deformation of the leading core soil is the real cause of tunnel deformation. When the excavation using the step method, the existence of the core soil on the face limits the horizontal displacement of the soil on the face, so in the past, only the deformation monitoring of the surrounding rock in the radial direction of the tunnel was focused. After the full-section excavation is adopted, the core soil is not left, and the stability of the face soil is the premise of ensuring the safety of tunnel construction and preventing landslides. In order to realize the real-time monitoring of the horizontal displacement of the core soil in front of the excavation face of the full section of the tunnel, and to grasp its deformation law.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the technical problems existing in the prior art, and to provide a device and method for monitoring the horizontal displacement of soil in the deep part of the tunnel face, which can quickly close the initial branch into a ring to form a bearing structure, and can effectively control the tunnel face. The surrounding rock behind the sub-face is radially deformed to control the surface settlement and ensure the safety of tunnel construction.

The object of the present invention is achieved through the following technical solutions:

The invention provides a device for monitoring the horizontal displacement of soil in the deep part of a tunnel face, which comprises:

PVC pipes, displacement sensors, rubber grommets, steel wires and steel wire retainers;

A displacement sensor is fixed on the inner wall of one end of each PVC pipe. Multiple PVC pipes are connected by rubber leather rings. Each displacement sensor pulls out a steel wire and is tightened and fixed to the last PVC pipe through the steel wire holder. the end of .

More preferably, the length of the horizontal displacement monitoring device is 1.5 to 2 times the equivalent excavation diameter of the face.

More preferably, the length of each PVC pipe is selected according to the monitoring accuracy.

More preferably, the displacement sensor comprises a single-point vibrating wire displacement sensor.

The present invention also provides a method for monitoring the horizontal displacement of soil in the deep part of the tunnel face, comprising:

Step S101, determining the length of the horizontal displacement monitoring device according to the equivalent excavation diameter of the tunnel face, and determining the length of each PVC pipe according to the monitoring accuracy;

Step S102, assemble the horizontal displacement monitoring device: a displacement sensor is fixed on the inner wall of one end of each PVC pipe, a plurality of PVC pipes are connected by a rubber leather ring, each displacement sensor pulls out a steel wire, and passes through the The wire retainer is tightened to the end of the last PVC pipe;

Step S103, laying out the tunnel face monitoring points, and then using a drilling rig to drill holes for each monitoring point along the tunnel excavation direction to form a plurality of monitoring holes;

Step S104, inserting the assembled horizontal displacement monitoring device into the monitoring hole, inserting one end of the PVC pipe gathered by the steel wires into the deepest part of the monitoring hole, and assuming that one end of the PVC pipe gathered by the steel wire is a fixed point of horizontal displacement;

Step S105, pouring cement slurry to fill the gap between the monitoring hole and the PVC pipe, so that the PVC pipe and the soil on the tunnel face are tightly and firmly bonded together;

Step S106, energize the horizontal displacement monitoring device, monitor the extrusion deformation of the leading core soil on the face in real time, transmit all monitoring data to the monitoring platform through electrical signals, and automatically calculate the measurement of each monitoring hole on the face. The horizontal displacement of the soil at the point location.

As can be seen from the above technical solutions of the present invention, the present invention has the following technical effects:

The horizontal displacement monitoring device of the invention is suitable for monitoring the horizontal displacement of the core soil in front of the tunnel engineering face, the operation is simple and the method is reliable, and the monitoring data obtained by the invention can reflect the extrusion of the core soil in front of the face to the greatest extent. The deformation provides a basis for evaluating the stability of the tunnel face during full-section excavation.

Description of drawings

Fig. 1 is the structural representation of the horizontal displacement monitoring device of the present invention;

Fig. 2 is the effect diagram that the horizontal displacement monitoring device of the present invention is installed on the deep soil body of the face;

FIG. 3 is a flow chart of the implementation of the horizontal displacement monitoring method of the present invention.

In the attached picture:

PVC pipe 11 , displacement sensor 12 , rubber ring 13 , steel wire 14 , steel wire holder 15 ; horizontal displacement monitoring device 1 ; tunnel face 2 .

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present application, the present invention will be further described in detail below with reference to the accompanying drawings.

Orientation terms such as upper, lower, left, right, front and rear in this application document are established based on the positional relationship shown in the accompanying drawings. If the drawings are different, the corresponding positional relationship may also change accordingly, so this should not be construed as a limitation on the protection scope.

In the present invention, "installation", "connected", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral Connection can be mechanical connection, electrical connection or mutual communication, direct connection or indirect connection through an intermediate medium, internal communication between two components, or two components interaction relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

The present invention provides a device for monitoring the horizontal displacement of soil in the deep part of the tunnel face. The steel wire holder 15 is composed.

A displacement sensor 12 is fixed on the inner wall of one end of each PVC pipe 11, which can be glued or fixed with screws; a plurality of such PVC pipes are connected by rubber rubber rings 13, and each displacement sensor 12 pulls out a steel wire 14, and is tightened and fixed to the end of the last PVC pipe 11 through a steel wire holder 15; the steel wire holder 15 is an aluminum cover with multiple round holes, which is convenient for multiple steel wires 14 to pass through and tighten. After spot welding and sealing the hole, the steel wire holder 15 and the end of the PVC pipe 11 are fixed with screws.

A signal transmitter is attached to each displacement sensor 12, the electrical signals are transmitted through wireless transmission, and all signals are received through the data collector outside the cave.

The length of the horizontal displacement monitoring device should be 1.5 to 2 times the equivalent excavation diameter of the face. The length and quantity of each PVC pipe 11 can be selected according to the monitoring accuracy. The monitoring accuracy (within a fixed monitoring length, the more measuring points and the more data collected, the higher the monitoring accuracy of the horizontal displacement of this section of soil). ), the shorter the length of each PVC pipe, and the number of PVC pipes in the monitoring length will increase, which is equivalent to increasing the number of measuring points and improving the monitoring accuracy.

The above-mentioned displacement sensor 12 may be a single-point vibrating wire displacement sensor.

The installation situation of the horizontal displacement monitoring device of the present invention is as follows:

When using the horizontal displacement monitoring device of the present invention, first, assemble the horizontal displacement monitoring device 1 on the construction site according to FIG. 1; the length of the horizontal displacement monitoring device 1 should be 1.5 to 2 times the equivalent excavation diameter of the face;

Then, as shown in Figure 2, monitoring points are arranged on the tunnel face 2, and the drilling rig is used to drill holes at each monitoring point along the tunnel excavation direction to form multiple monitoring holes; the length of the monitoring holes should be greater than the length of the horizontal displacement monitoring device 1 .

Next, insert the assembled horizontal displacement monitoring device 1 into the monitoring hole. When inserting, insert one end of the PVC pipe where the thin steel wires are gathered into the deepest part of the monitoring hole, and assume it as the fixed point of horizontal displacement.

Then, the gap between the monitoring hole and the PVC pipe 11 of the horizontal displacement monitoring device 1 is filled with cement slurry, and the end of the pipe is closed, so that the PVC pipe 11 and the soil of the tunnel face 2 are tightly and firmly bonded together.

Finally, the horizontal displacement monitoring device 1 is energized, and the horizontal displacement monitoring device 1 is used to monitor the extrusion deformation of the leading core soil on the face of the tunnel in real time. All monitoring data are transmitted to the monitoring platform through electrical signals, and the The horizontal displacement of the soil at each monitoring point in each monitoring hole on the surface.

The present invention also provides a method for monitoring the horizontal displacement of soil in the deep part of the tunnel face. The specific implementation process is shown in Figure 3, including the following steps:

Step S101, determine the length of the horizontal displacement monitoring device according to the equivalent excavation diameter of the tunnel face, and the length of the horizontal displacement monitoring device should be 1.5 to 2 times the equivalent excavation diameter of the tunnel face; and determine according to the monitoring accuracy The length of each PVC pipe 11. The higher the monitoring accuracy is, the shorter the length of each PVC pipe 11 is.

Step S102, the horizontal displacement monitoring device is assembled outside the tunnel construction hole. A displacement sensor 12 is fixed on the inner wall of one end of each PVC pipe 11 , and a plurality of such PVC pipes are connected by a rubber rubber ring 13 . Fasten tightly to the end of the last PVC pipe 11.

Step S103, laying out monitoring points on the tunnel face, and then using a drilling rig to drill holes for each monitoring point along the tunnel excavation direction to form a plurality of monitoring holes. The length of the monitoring hole is greater than the length of the horizontal displacement monitoring device.

Step S104, inserting the assembled horizontal displacement monitoring device into the monitoring hole, inserting one end of the PVC pipe 11 where the steel wires are gathered into the deepest part of the monitoring hole, and assuming that one end of the PVC pipe 11 gathering the steel wires does not move horizontally point.

Step S105, pouring cement slurry to fill the gap between the monitoring hole and the PVC pipe 11, so that the PVC pipe 11 and the soil on the tunnel face are tightly and firmly bonded together.

Step S106, power on the horizontal displacement monitoring device to monitor the extrusion deformation of the leading core soil on the face in real time, and transmit all the monitoring data to the monitoring platform through electrical signals, and automatically calculate the number of holes in each monitoring hole on the face. The horizontal displacement of the soil at the measuring point.

The measuring points are defined as 1, 2, 3, 4...n from the tunnel facing the deep part of the soil body, and the displacement from the displacement sensor of each measuring point is defined as C1, C2, C3... ··Cn, the horizontal displacement of the monitored soil at each measuring point is defined as S1, S2, S3...Sn, then there are:

S1=C1-C2, S2=C2-C3, Sn-1=Cn-1-Cn, Sn=Cn).

The horizontal displacement monitoring device of the invention is suitable for monitoring the horizontal displacement of the core soil in front of the tunnel engineering face, and is easy to operate; the monitoring method of the invention is reliable, and the monitoring data can reflect the extrusion deformation of the core soil in front of the face to the greatest extent. , to provide a basis for evaluating the stability of the tunnel face during full-section excavation.

Although the present invention has been disclosed above with preferred embodiments, the embodiments do not limit the present invention. Any equivalent changes or modifications made without departing from the spirit and scope of the present invention also belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the content defined by the claims of the present application.

Claims (5)

1. The utility model provides a tunnel face deep soil body horizontal displacement monitoring devices which characterized in that, horizontal displacement monitoring devices include:

the device comprises a PVC pipe (11), a displacement sensor (12), a rubber leather ring (13), a steel wire (14) and a steel wire fixer (15);

a displacement sensor (12) is fixed on the inner wall of one end of each PVC pipe (11), the PVC pipes are connected through rubber leather rings (13), each displacement sensor (12) draws a steel wire (14) and is tensioned and fixed to the tail end of the last PVC pipe (11) through a steel wire fixer (15).

2. The device for monitoring the horizontal displacement of the soil body at the deep part of the tunnel face of the tunnel according to claim 1,

the length of the horizontal displacement monitoring device is 1.5-2 times of the equivalent excavation diameter of the tunnel face.

3. The device for monitoring the horizontal displacement of the soil body at the deep part of the tunnel face of the tunnel according to claim 1,

the length and number of each PVC pipe (11) is selected according to the monitoring accuracy.

4. The device for monitoring the horizontal displacement of the soil body at the deep part of the tunnel face of the tunnel according to claim 1,

the displacement sensor (12) comprises a single-point vibrating wire type displacement sensor.

5. A method for monitoring horizontal displacement of deep soil body on a tunnel face is characterized by comprising the following steps:

s101, determining the length of a horizontal displacement monitoring device according to the equivalent excavation diameter of the tunnel face, and determining the length of each PVC pipe (11) according to the monitoring precision;

step S102, assembling the horizontal displacement monitoring device: a displacement sensor (12) is fixed on the inner wall of one end of each PVC pipe (11), the PVC pipes are connected through a rubber leather ring (13), each displacement sensor (12) draws a steel wire (14) and is tensioned and fixed to the tail end of the last PVC pipe (11) through a steel wire fixer (15);

step S103, laying tunnel face monitoring points, and then drilling holes in the monitoring points along the tunnel excavation direction by using a drilling machine to form a plurality of monitoring holes;

step S104, inserting the assembled horizontal displacement monitoring device into a monitoring hole, inserting one end of the PVC pipe (11) converged by the steel wire into the deepest part of the monitoring hole, and assuming one end of the PVC pipe (11) converged by the steel wire as a horizontal displacement immobile point;

s105, filling the gap between the monitoring hole and the PVC pipe (11) with cement paste to tightly and firmly bond the PVC pipe (11) and the soil body on the tunnel face;

and S106, finally, electrifying the horizontal displacement monitoring device, monitoring the extrusion deformation of the core soil ahead of the tunnel face in real time, transmitting all monitoring data to a monitoring platform through electric signals, and automatically calculating to obtain the horizontal displacement of the soil body at each measuring point position of each monitoring hole of the tunnel face.

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