CN218373892U - Distributed monitoring device for foundation pit anchor rod - Google Patents

Abstract

The utility model discloses a distributed monitoring device of foundation pit anchor rod, which comprises a first anchor rod and a second anchor rod, wherein the outer wall where the first anchor rod is positioned is provided with a sensing optical cable arranged along the axis direction, one end part of the sensing optical cable is connected to a control center, and the other end part of the sensing optical cable is led out from the tail part of the first anchor rod to the head part along the axis outer wall and then is led out reversely; two groups of expanders are arranged at the front end part where the second anchor rod is located, and meanwhile, the expanders expand outwards and expand and reinforce rock and soil mass on the inner wall of a drilled hole, and the sensing optical cable led out from the first anchor rod is led out to the head part along the outer wall of the axis from the tail part of the second anchor rod and then led out reversely; the first anchor rod and the second anchor rod are horizontally arranged in horizontal drill holes of different depth stratums of the foundation pit from top to bottom. The stress strain of each point along the sensing optical cable can be obtained, the full-distributed monitoring of the stress deformation of the anchor rod is realized, the defects of omission and multiple leads of the traditional point type monitoring are overcome, and the monitoring efficiency is greatly improved.

Description

A distributed monitoring device for foundation pit bolts

technical field

The utility model belongs to the technical field of foundation pit monitoring, in particular to a distributed monitoring device for foundation pit bolts.

Background technique

With the acceleration of the urbanization process, a large number of high-rise buildings are constantly being built, and the depth and scale of foundation pits are increasing. Correspondingly, the requirements for the stability of foundation pit engineering are getting higher and higher. As the main means of foundation pit support, bolts have the advantages of light structure, strong flexibility, good ductility, low cost, simple construction, strong adaptability, short construction period and little impact on the environment. widely used.

During the construction of the deep foundation project, as the excavation proceeds, the unloading of the soil inside the foundation project will cause the rebound of the base; the retaining structure interacts with the surrounding soil of the foundation project. If the design of the support structure is unreasonable, resulting in rigidity and strength Insufficient support structures will cause accidents such as tilting of support structures, soil landslides, and foundation engineering collapses; at the same time, engineering geological problems caused by the precipitation process of foundation engineering construction also occur frequently, such as soil consolidation, which leads to uneven ground settlement of surrounding soil , Seriously bring ground fissure disasters, and there are also sandy soil losses due to pumping in sandy soil strata, and even pipe gushing and quicksand accidents.

As the main means of foundation support, bolts have the advantages of light structure, strong flexibility, good ductility, low cost, simple construction, strong adaptability, short construction period and little impact on the environment, and are widely used in foundation support Therefore, it is very important to evaluate the working performance and long-term reinforcement effect of anchor rods in foundation engineering support. For this reason, it is necessary to adopt corresponding technical means to monitor and monitor the stress and strain changes of the anchor bolt in the foundation engineering support process.

Utility model content

Aiming at the deficiencies of the prior art, the purpose of this utility model is to provide a distributed monitoring device for foundation pit bolts, which solves the above-mentioned technical problems existing in the prior art.

The purpose of this utility model can be realized through the following technical solutions:

A distributed monitoring device for foundation pit anchors, comprising a first anchor and a second anchor, the first anchor is in a straight tubular structure, and at the same time, the outer wall where the first anchor is located is provided with a Sensing optical cable, one end of the sensing optical cable is connected to the control center, and the other end is drawn from the tail of the first anchor rod along the outer wall of the axis to the head and then reversed;

The front end where the second anchor rod is located is provided with two sets of expanders, and at the same time, the expanders are used to expand outwards and expand and reinforce the rock and soil mass on the inner wall of the borehole, thereby improving the anchoring performance of the anchor rod. The extracted sensing optical cable continues to be drawn from the tail of the second anchor along the outer wall of the axis to the head and then reversed;

The first anchor rod and the second anchor rod are arranged horizontally up and down in the horizontal boreholes in different depths of the foundation pit.

Further, the first anchor rod and the second anchor rod are distributed and connected in a multi-section tubular shape, and are connected to each other through flanges.

Further, the outer wall where the first anchor rod and the second anchor rod are located is provided with two sets of reinforcements along the direction of the symmetry axis, and the sensing optical cable is laid in the gap between the reinforcement members and the outer walls of the first anchor rod and the second anchor rod.

Further, the outer wall where the first anchor rod and the second anchor rod are located is wrapped with a resin coating film layer, so that the sensing optical cable is wrapped on the outer wall where the first anchor rod and the second anchor rod are located; A cloth tape is arranged on the outer side where the film layer is located.

Further, the sensing optical cable leading out from the first anchor rod is connected to the sensing optical cable leading in on the second anchor rod by welding.

The beneficial effects of the utility model:

1. The sensor optical cable on the first anchor rod and the second anchor rod used in this device simultaneously measures the conditions in boreholes at different depths, and adopts the welding method to realize the continuity of the sensing data of the sensing optical cable and improve the monitoring accuracy.

2. Compared with the traditional point sensor, the most significant advantage of the distributed optical fiber sensing technology is that it can measure the stress and strain of each point along the sensing fiber, realize the fully distributed monitoring of the force deformation of the anchor rod, and overcome the traditional point of view. The shortcomings of missed detection and numerous lead wires of traditional monitoring greatly improve the monitoring efficiency.

3. The sensing optical cable used in this device is light in weight and small in size, easy to lay and install on the anchor rod, and can obtain reliable monitoring data for evaluating the safety and stability of the basic engineering.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings that are required in the description of the embodiments or the prior art.

Fig. 1 is the overall structural representation of the utility model embodiment;

Fig. 2 is a schematic diagram of the overall structure of the first anchor rod in the embodiment of the present invention;

Fig. 3 is a schematic diagram of the cross-sectional structure of the first anchor rod in the embodiment of the present invention;

Fig. 4 is a schematic diagram of the overall structure of the second anchor rod according to the embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

As shown in Figure 1, the embodiment of the utility model provides a distributed monitoring device for foundation pit anchors, including a first anchor 1 and a second anchor 2, as shown in Figures 2 and 3, the first anchor 1 is a straight tubular structure, and at the same time, the outer wall where the first anchor rod 1 is located is provided with a sensing optical cable 3 arranged along the axial direction. One end of the sensing optical cable 3 is connected to the control center, and the other end is connected to the The tail is drawn out along the outer wall of the axis to the head, and then drawn out in reverse along the outer wall of the symmetrical axis; at this time, the first anchor rods 1 are distributed and connected in a multi-section tubular shape, and are connected to each other through the flange 101 . And the outer wall where the first anchor rod 1 is located is provided with two groups of symmetrical steel bars 102 along the axial direction, and the sensing optical cable 3 is laid in the gap between the steel bar 102 and the first anchor bar 1, at this time, the sensing optical cable 3 is prevented from being crushed and damaged , then the outer wall where the first anchor rod 1 is located is wrapped with a resin coating film layer 11, so that the sensing optical cable 3 is wrapped on the outer wall where the first anchor rod 1 is located, and then the resin coating film layer 11 is covered by the cloth tape 12 The wrapped steel bar 102 and the outer wall of the sensing optical cable 3 are wrapped twice, which can reduce the friction damage of the hole wall to the surface of the sensing optical cable 3 when the bolt is pushed into the drilling process, improve the survival rate of the sensing optical cable 3, and ensure its Coupling performance with the anchor rod.

As shown in Figure 4, two groups of expanders 21 are arranged at the front end of the second anchor rod 2 (connected in a multi-section tubular distribution according to requirements, and are connected to each other through flanges 101). External expansion and expansion and reinforcement of the rock and soil mass on the inner wall of the borehole (suitable for soft soil layers), which improves the anchoring performance of the anchor rod. The sensing optical cable 3 drawn from the first anchor rod 1 continues from the second anchor rod 2 The tail is led out along the outer wall of the axis to the head and then reversely drawn out along the outer wall of the symmetrical axis. At this time, the outer wall where the second anchor rod 2 is located is provided with two groups of symmetrical steel bars 102 along the axial direction, so that the sensing optical cable 3 is located on the outer wall of the steel bar 102 The gap with the outer wall of the second anchor rod 2 is arranged, and at this time, the sensing optical cable 3 is prevented from being damaged by friction, and then the outer wall where the second anchor rod 2 is located is wrapped with a resin coating film layer 11 (not specifically shown in the figure, refer to the first A similar arrangement of the first anchor 1), so that the sensing optical cable 3 is wrapped on the outer wall where the first anchor 1 is located, and then passes through the duct tape 12 (not specifically shown in the figure, see the similar arrangement of the first anchor 1 ) performing secondary wrapping on the reinforcing bar 102 wrapped by the resin coating film layer 11 and the outer wall of the sensing optical cable 3, which can reduce the friction damage of the inner wall of the drilled hole to the surface of the sensing optical cable 3, and improve the survival rate of the sensing optical cable 3, And ensure its coupling performance with the anchor rod (refer to the similar setting of the first anchor rod 1).

The sensing optical cable 3 leading out from the first anchor rod 1 is connected to the sensing optical cable 3 leading in on the second anchor rod 2 by means of fusion. The first anchor rod 1 and the second anchor rod 2 are arranged horizontally up and down in boreholes in formations of different depths in the foundation pit.

Specific usage method: (1) Horizontally press the bolt with the strain sensing optical cable into the pre-constructed horizontal borehole with a flat pusher.

(2) Select grouting materials according to the ratio of design requirements for grouting.

(3) When the grouting strength meets the specification requirements, install the counterforce device and pull-out test related equipment.

(4) The cyclic loading method is usually used for loading. After each loading, the optical fiber data is collected after the load is stable until the end of the entire loading test.

The fully distributed monitoring is carried out by using the linear relationship between the variation of the spontaneous Burrillouin scattering frequency and the strain variation in the optical fiber. Compared with traditional point sensors, the most significant advantage of distributed optical fiber sensing technology is that it can measure the stress and strain at each point along the sensing fiber, realize fully distributed monitoring of monitoring objects, and overcome the shortcomings of traditional point monitoring. The shortcomings of many detection and lead wires greatly improve the monitoring efficiency. At the same time, the optical fiber is light in weight and small in size, so it is easy to lay and install on the anchor rod. Therefore, this scheme proposes a distributed anchor rod for support monitoring of deep foundation engineering, which can monitor and evaluate the safety and stability of foundation engineering.

After the installation is completed, the control center uses a distributed data acquisition system to collect data in the borehole through the sensing optical cable 3 on the first anchor rod 1 and the second anchor rod 2 .

The basic principles, main features and advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model.

Claims (4)

1. A distributed monitoring device for foundation pit anchor rods comprises a first anchor rod (1) and a second anchor rod (2), and is characterized in that the first anchor rod (1) is of a straight pipe-shaped structure, a sensing optical cable (3) arranged along the axis direction is arranged on the outer wall where the first anchor rod (1) is located, one end of the sensing optical cable (3) is connected to a control center, and the other end of the sensing optical cable is led out from the tail of the first anchor rod (1) to the head along the outer wall of the axis and then led out reversely;

two groups of expanders (21) are arranged at the front end part of the second anchor rod (2), and meanwhile, the expanders (21) are used for expanding outwards and expanding and reinforcing rock and soil mass on the inner wall of a drilled hole, and the sensing optical cable (3) led out from the first anchor rod (1) is led out from the tail part of the second anchor rod (2) to the head part along the outer wall of the axis and then led out reversely;

the first anchor rod (1) and the second anchor rod (2) are transversely arranged in horizontal drill holes of strata at different depths of the foundation pit;

the first anchor rod (1) and the second anchor rod (2) are distributed and connected in a multi-section tubular mode and are connected with each other through flange pieces (101).

2. The distributed monitoring device for the foundation pit anchor rods according to claim 1, wherein two sets of steel bar members (102) are arranged on the outer wall of the first anchor rod (1) and the outer wall of the second anchor rod (2) along the axis direction of the symmetry axis, and the sensing optical cable (3) is arranged in a gap between the steel bar members (102) and the outer walls of the first anchor rod (1) and the second anchor rod (2).

3. The distributed monitoring device for the foundation pit anchor rods is characterized in that the outer walls of the first anchor rods (1) and the second anchor rods (2) are wrapped with resin coating films (11), so that the sensing optical cables (3) are wrapped on the outer walls of the first anchor rods (1) and the second anchor rods (2); and a cloth-based adhesive tape (12) is arranged on the outer side of the resin coating layer (11).

4. A distributed monitoring apparatus for foundation pit anchoring rods according to claim 3, characterized in that the sensing optical cable (3) led out from the first anchoring rod (1) is connected with the sensing optical cable (3) led in from the second anchoring rod (2) by welding.

Images