CN115637707A - Tunnel foundation pit supporting structure and construction method thereof - Google Patents

Abstract

The invention provides a tunnel foundation pit supporting structure and a construction method thereof, wherein the tunnel foundation pit supporting structure comprises a supporting rod steel pipe, two ends of the supporting steel pipe are detachably and fixedly provided with connecting steel pipes, one end of each connecting steel pipe, which is opposite to the supporting steel pipe, is fixedly provided with a supporting plate, one side, which is opposite to the connecting steel pipe, of each supporting plate is provided with a supporting groove for placing a jack, sliding cylinders are symmetrically arranged on the supporting plates on two sides of each supporting groove, supporting legs are arranged in the sliding cylinders in a sliding manner, sockets are formed in the tops of the supporting legs, supporting plates are inserted into the sockets, and the supporting plates are right-angled trapezoid plate bodies; the side both ends of backup pad support through two supporting legss respectively with enclose between the purlin, promote the reliability of supporting, a backup pad slippage when avoiding independently supporting and cause the axial force loss, guarantee the supporting effect to the backup pad is convenient for install fast and demolish, is favorable to promoting the construction progress.

Description

Tunnel Foundation Pit Supporting Structure and Its Construction Method

technical field

The invention belongs to the technical field of foundation pit support construction, and in particular relates to a tunnel foundation pit support structure and a construction method thereof.

Background technique

With the vigorous development of my country's urban rail transit construction, the number of open-excavation foundation pit projects is gradually increasing, the excavation depth is gradually deepening, and the structural forms are complex and diverse. Most of the subway stations are located in the bustling areas of the city, the surrounding environment is complex, buildings and various pipelines are dense, and the requirements for the effect of foundation pit support and deformation control are getting higher and higher.

In the prior art, for example, the Chinese invention patent application document with the publication number CN109356168A discloses a steel supporting joint, including a base, an outer cylinder assembly movably connected with the base, the base includes a bottom plate, and at least two The screw is threaded with a nut. The outer cylinder assembly includes an outer cylinder and a limiting plate installed at one end of the outer cylinder. The limiting plate is provided with an opening for the screw to pass through. The nut is located between the bottom plate and the limiting plate. Rotate the nut to adjust the distance between the limiting plate and the bottom plate.

In the above-mentioned prior art, the active end, which is prone to loss of axial force, is fixed by screws and nuts, and the adjusting nut needs to be rotated continuously during the fixing or releasing process, which consumes a lot of time and is not conducive to its rapid installation and removal. , affecting the construction progress.

Therefore, it is necessary to design a tunnel foundation pit support structure and its construction method that are not prone to axial force loss and are easy to install and dismantle quickly to solve the current technical problems.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a tunnel foundation pit support structure that is not prone to loss of axial force and is convenient for quick installation and dismantling, and a construction method thereof.

The technical solution of the present invention is: the support structure of the tunnel foundation pit, including a support rod steel pipe, the two ends of the support steel pipe are detachably and fixedly provided with connecting steel pipes, and the end of the connecting steel pipe that is away from the supporting steel pipe is fixedly arranged There is a support plate, the side of the support plate that is away from the connecting steel pipe is provided with a bracket for placing a jack, and the support plates on both sides of the bracket are symmetrically provided with sliders, and the sliders There are support feet slidingly arranged inside the support feet, and sockets are opened on the top of the support feet, and a support plate is inserted into the socket, and the support plate is a right-angled trapezoidal plate body.

The inside of the bracket is provided with a partition along the axial direction of the connecting steel pipe, and the partition is fixed vertically on the inner bottom of the bracket, and the inside of the bracket on both sides of the partition is provided with jack.

The front ends of the cylinder bodies of the two jacks are respectively fixedly provided with front end plates, and the rear ends of the cylinder bodies of the two jacks are fixedly connected with a rear end plate.

The tops of the front end plate and the rear end plate are provided with lifting holes.

The brackets on both sides of the partition are provided with positioning grooves inside, and the top of the positioning grooves is provided with an arc-shaped groove matching the outside of the cylinder of the jack.

The inner side of the sliding cylinder has a sliding cavity, the supporting foot has a cross tube matching the sliding cavity, and the socket is opened on the top of the cross tube.

A support end plate is fixedly provided on the end of the cross tube away from the sliding cylinder, and a backing plate is fixedly provided on the side of the support end plate away from the cross tube.

A reinforcing plate is arranged between the supporting plate and the connecting steel pipe, and a side plate is arranged between the reinforcing plates.

Teeth are uniformly formed on the hypotenuse of the support plate.

The construction method of tunnel foundation pit support comprises the following steps:

Adopt the tunnel foundation pit support structure as described in any one of the above;

When the position of a support is excavated, the supporting structure of the foundation pit of the hoisting tunnel is put in place, and it is put in place with an inverted chain and fine-tuned. , to ensure that the ends of the supporting feet are in close contact, and the action of the jack is controlled to apply prestress according to the design requirements;

After the prestress is applied to the design requirements, insert the support plate into the socket for support to ensure close contact and prevent the loss of prestress, and then return the oil to loosen the jack to complete the support installation and prestress application of the tunnel foundation pit support structure.

Beneficial effects of the present invention:

(1) In the present invention, when the position of a support is excavated, the support structure of the tunnel foundation pit is hoisted in place, and the chain is used to fit in place and fine-tuned, and a jack is placed inside the bracket, and the support foot is aligned after being in the correct position. The gap between the head and the purlin is filled and leveled with fine stone quick-hardening concrete to ensure that the ends of the supporting feet are in close contact, and the action of the jack is controlled to apply prestress according to the design requirements. After the prestress is applied to the design requirements, insert the support plate into the socket for support , to ensure close contact and prevent the loss of prestress, and then return the oil to loosen the jack to complete the support installation and prestress application of the tunnel foundation pit support structure;

(2) The two ends of the side of the support plate are respectively supported by two support feet and the purlins to improve the reliability of the support, avoid the loss of axial force caused by a support plate slipping when independently supported, and ensure the support effect, and the support plate is convenient and fast Installation and dismantling are conducive to improving the construction progress.

Description of drawings

Fig. 1 is a structural schematic diagram of a tunnel foundation pit supporting structure in the present invention.

Fig. 2 is one of the local structural schematic diagrams of the tunnel foundation pit support structure in the present invention.

Fig. 3 is the second schematic diagram of the local structure of the tunnel foundation pit support structure in the present invention.

Fig. 4 is the third schematic diagram of the partial structure of the tunnel foundation pit support structure in the present invention.

Fig. 5 is a schematic diagram of a partial structure of a support plate in the present invention.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is illustrative only and in no way restrictive of the invention, its application or uses. The present invention can be implemented in many different forms and is not limited to the embodiments described here. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It should be noted that relative arrangements of parts and steps, compositions of materials, numerical expressions and numerical values set forth in these embodiments should be interpreted as illustrative only and not as limiting, unless specifically stated otherwise.

"First", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different parts. Words like "comprising" or "comprising" mean that the elements preceding the word cover the elements listed after the word, and do not exclude the possibility of also covering other elements. "Up", "Down", "Left", "Right" and so on are only used to indicate the relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

As shown in Figures 1 to 5, the tunnel foundation pit support structure includes a support rod steel pipe 1, the two ends of the support steel pipe 1 are detachably fixed with a connecting steel pipe 2, and the end of the connecting steel pipe 2 that is away from the supporting steel pipe 1 is fixed and fixed There is a support plate 3, and the support plate 3 is welded and fixed on the end of the connecting steel pipe 2, and the side of the supporting plate 3 that is away from the connecting steel pipe 2 is provided with a bracket 8 for placing a jack, and the bracket 8 is welded and fixed on the supporting plate 3 In the middle of one side, the support plate on both sides of the bracket 8 is symmetrically provided with a slide tube 4, the inside of the slide tube 4 is slidingly provided with a support foot 5, and the top of the support foot 5 is provided with a socket, and the socket 51 is inserted with a support plate 6. The supporting plate 6 is a right-angled trapezoidal plate body; in this embodiment, when a supporting position is excavated, then the supporting structure of the tunnel foundation pit is hoisted in place, and the back chain is used to fit it in place and fine-tune it, and then guide it to the bracket. 8. Place the jack 7 inside. After the correct position, use fine stone fast-hardening concrete to fill and level the space between the end of the support foot 5 and the purlin to ensure that the end of the support foot 5 is in close contact. Control the action of the jack to apply prestress according to the design requirements. After applying the design requirements, insert the support plate 6 into the socket 51 for support to ensure close contact and prevent the loss of prestress, and then return the oil to loosen the jack 7 to complete the support installation and prestress application of the tunnel foundation pit support structure; support The two ends of the side of the plate 3 are respectively supported by two support feet 5 and the purlins to improve the reliability of the support, avoid the loss of axial force caused by a support plate 6 slipping when independently supported, and ensure the support effect, and the support plate 6 is convenient and fast Installation and dismantling are conducive to improving the construction progress.

In some embodiments, the inside of the bracket 8 is provided with a partition 81 along the axial direction of the connecting steel pipe 2, the partition 81 is fixed vertically on the inner bottom of the bracket 8, and the bottom of the partition 81 is welded and fixed on the bottom of the bracket 8. In the inner bottom, the inside of the bracket 8 on both sides of the partition 81 is provided with a jack 7, and the inside of the bracket 8 is separated into two areas by the partition 81, which is convenient for positioning with the two jacks 7 inside the bracket 8 to ensure that the jack 7 Stability during use.

In some embodiments, the front ends of the cylinder body of the two jacks 7 are respectively fixedly provided with front end plates 72, and the front end plates 72 are assembled and fixed on the front ends of the cylinder body of the jack 7 by bolts. The end plate 71 is fixedly connected, and the rear end plate 71 is assembled and fixed on the cylinder rear end of the jack 7 by bolts, and the two jacks 7 are connected into an integral structure by the rear end plate 71, so that the top extension force of the two jacks 7 can be kept consistent.

In some embodiments, the tops of the front end plate 72 and the rear end plate 71 are provided with lifting holes 73, through the lifting holes 73, it is convenient to put the jack 7 into the bracket 8, or take out the jack 7 from the bracket 8. .

In some embodiments, positioning slots 82 are provided inside the brackets 8 on both sides of the partition 81, and the top of the positioning slots 82 is provided with an arc-shaped slot matching the outside of the cylinder body of the jack 7. The shaped groove can position the 7-cylinder body of the jack, further improving its stability.

In some embodiments, the inner side of the sliding cylinder 4 has a sliding cavity 41, and the supporting foot 5 has a cross tube 52 matching the sliding cavity 41. The interior of 41 is in contact with sliding connection around.

In some embodiments, the end of the cross tube 52 facing away from the sliding cylinder 4 is fixedly provided with a supporting end plate 53, and the side of the supporting end plate 53 facing away from the cross tube 52 is fixedly provided with a backing plate 54 to support the end plate 53 Weld the stator, the end of the cross pipe 52, and the backing plate 54 is supported by a rubber plate, which can play a certain buffering role between the supporting end plate 53 and the purlin, and at the same time can increase the friction between the supporting end plate 53 and the purlin force.

In some embodiments, a reinforcing plate 31 is arranged between the supporting plate 3 and the connecting steel pipe 2, the reinforcing plate 31 is a right-angled trapezoidal plate body, and a side plate 32 is arranged between the reinforcing plates 31, the side plate 32, the reinforcing plate 31, the support Both the plate 3 and the connecting steel pipe 2 are fixed by welding.

In some embodiments, as shown in FIG. 5 , teeth 62 are evenly formed on the hypotenuse 61 of the support plate 6 , the teeth 62 can prevent the support plate 6 from slipping inside the socket 51 and ensure the stability of the support.

As an embodiment of the detachable and fixed connection between the supporting steel pipe 1 and the connecting steel pipe 2, a flange is provided at both ends of the supporting steel pipe 1, and a flange is provided at the end of the connecting steel pipe 2 close to the supporting steel pipe 1, and the supporting steel pipe 1 and The connecting steel pipe 2 is detachably and fixedly connected through a flange.

In some embodiments, a construction method for tunnel foundation pit support is disclosed, comprising the following steps:

Adopt the tunnel foundation pit support structure in any of the above-mentioned embodiments;

When the position of a support is excavated, then the supporting structure of the tunnel foundation pit is hoisted in place, fitted with an inverted chain and fine-tuned. Leveling, to ensure that the ends of the supporting feet are in close contact, and to control the action of the jack to apply prestress according to the design requirements;

After the prestress is applied to the design requirements, insert the support plate into the socket for support to ensure close contact and prevent the loss of prestress, and then return the oil to loosen the jack to complete the support installation and prestress application of the tunnel foundation pit support structure.

Strengthen the observation of the support prestress of the support structure of the tunnel foundation pit, observe the loss of prestress and the horizontal displacement of the wall within 12 hours after the first prestress is added, and add the prestress to the design value.

After the prestress of the supporting structure of the foundation pit of the next tunnel is applied, the stress of the supporting structure of the supporting structure of the foundation pit of the previous tunnel will decrease. At this time, according to the data of the monitoring unit, prestress is added to the supporting structure of the foundation pit of the previous tunnel until the design requirements are met.

When the large temperature difference between day and night leads to the loss of the supporting prestress of the tunnel foundation pit support structure, immediately increase the prestress of the corresponding tunnel foundation pit support structure to the design value during the low temperature period of the day.

So far, the embodiments of the present invention have been described in detail. Certain details well known in the art have not been described in order to avoid obscuring the inventive concept. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

The above-mentioned embodiments only express some implementations of the present invention, and the descriptions thereof are more specific and detailed, but should not be construed as limiting the scope of the patent for the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A support structure for a tunnel foundation pit, characterized in that it comprises a support rod steel pipe, the two ends of the support steel pipe are detachably and fixedly provided with a connecting steel pipe, and one end of the connecting steel pipe departing from the supporting steel pipe is fixed A support plate is provided, and a bracket for placing a jack is provided on the side of the support plate that is away from the connecting steel pipe. Sliders are symmetrically arranged on the support plates on both sides of the bracket. The inside of the barrel is slidably provided with support feet, and a socket is opened on the top of the support foot, and a support plate is inserted into the socket, and the support plate is a right-angled trapezoidal plate body. 2. The tunnel foundation pit support structure according to claim 1, characterized in that: the interior of the bracket is provided with a partition along the axial direction of the connecting steel pipe, and the partition is fixed vertically on the bracket The inner bottom of the groove and the inside of the brackets on both sides of the partition are provided with jacks. 3. The tunnel foundation pit support structure according to claim 2, characterized in that: the cylinder front ends of the two jacks are respectively fixed with front end plates, and the cylinder rear ends of the two jacks are connected with a rear End plate fixed connection. 4. The tunnel foundation pit support structure according to claim 3, characterized in that: the tops of the front end plate and the rear end plate are provided with lifting holes. 5. The tunnel foundation pit support structure according to claim 2, characterized in that: positioning slots are provided inside the brackets on both sides of the partition, and the top of the positioning slots is provided with a joint with the jack. Matching curved grooves on the outside of the cylinder block. 6. The tunnel foundation pit support structure according to claim 1, characterized in that: the inner side of the sliding cylinder has a sliding cavity, the supporting foot has a cross tube matching the sliding cavity, and the socket is opened at the top of the cross tube. 7. The tunnel foundation pit support structure according to claim 6, characterized in that: a support end plate is fixedly arranged on the end of the cross pipe away from the sliding cylinder, and the support end plate is connected to the The opposite side of the cross pipe is fixedly provided with a backing plate. 8. The tunnel foundation pit support structure according to claim 1, characterized in that: a reinforcing plate is arranged between the supporting plate and the connecting steel pipe, and a side plate is arranged between the reinforcing plates. 9. The tunnel foundation pit support structure according to claim 1, characterized in that teeth are evenly formed on the hypotenuse of the support plate. 10. A construction method for tunnel foundation pit support, characterized in that, comprising the following steps: Adopt the tunnel foundation pit support structure as described in any one of claims 1 to 9; When the position of a support is excavated, the supporting structure of the foundation pit of the hoisting tunnel is put in place, and it is put in place with an inverted chain and fine-tuned. , to ensure that the ends of the supporting feet are in close contact, and the action of the jack is controlled to apply prestress according to the design requirements; After the prestress is applied to the design requirements, insert the support plate into the socket for support to ensure close contact and prevent the loss of prestress, and then return the oil to loosen the jack to complete the support installation and prestress application of the tunnel foundation pit support structure.

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