Advanced small conduit structure for tunnel karst development section

Abstract

The utility model discloses an advanced small guide pipe structure for a tunnel karst development section, and belongs to the technical field of tunnel construction. The advanced small pipe structure comprises a steel pipe, the steel pipe is symmetrically divided into a left half steel pipe and a right half steel pipe along the central axis, and two fasteners are arranged between the left half steel pipe and the right half steel pipe; a plurality of steel floral tubes are movably arranged outside the steel tube in a sleeving manner, and each steel floral tube is also of a two-half structure. A groove is formed in the outer side wall of the steel pipe, a clamping block matched with the groove is arranged on the inner side wall of the steel floral pipe, and the front end and the rear end of the steel floral pipe are each of an inclined face structure. According to the advanced small guide pipe structure, grouting can be conducted on a tunnel cavity or a solution cavity through the steel pipe, the safety of tunnel construction is guaranteed, the supporting effect of the steel floral pipe is not affected after the steel pipe is pulled out, grouting is conducted on surrounding rock through the steel floral pipe, the steel floral pipe can be opened towards the two sides under the pressure effect of grout, and the construction efficiency is improved. And the effect of reinforcing the rock mass is further achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel construction, in particular to an advanced small conduit structure used in a karst development section of a tunnel. Background Art

[0002] During the tunnel construction process, when the tunnel geological survey determined that it was a karst tunnel, according to the on-site conditions, there was excessive settlement near the face, and according to the advance forecast, a large number of cavities or voids were found in front of the face. After analysis, the stratum composition revealed by the excavation is mainly limestone, which is gray and soft rock, easily softened by water. There are many mirrors and scratches in the rock mass. The groundwater flows out of the excavation face in strands. The surrounding rock stability is extremely poor. The vault and side walls are prone to local block drop or overall collapse. For this kind of tunnel construction geological environment, it is speculated that there may be a large number of cavities and voids in front of the face, and the cavity filling and tunnel reinforcement work need to be carried out in this section.

[0003] The small advance conduit is usually used for the reinforcement of poor geological conditions in tunnels, but most of the small conduits are steel pipes and cannot be used for filling tunnel cavities. Ordinary steel pipes are often used for cavity filling. Due to the complex on-site conditions and the poor geological conditions of the strata around the cavity, grouting reinforcement work is usually required. Although the steel pipe can be pulled out and reused after grouting, due to the uncertainty of the size of the steel pipe, different sizes of steel pipes must be made each time, or the excess steel pipes must be cut off after grouting, which is time-consuming and labor-intensive and causes a lot of waste. Summary of the invention

[0004] In view of the above-mentioned problems, the utility model aims to provide an advanced small guide tube structure for the karst development section of the tunnel. Through the cooperation of the steel pipe and the steel flower pipe, the tunnel cavity or the dissolution cavity can be filled with grouting through the steel pipe. After the cavity is filled, the steel pipe can be pulled out and grouting can continue through the steel flower pipe to achieve reinforcement of the surrounding rock.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] An advanced small conduit structure for a karst development section of a tunnel comprises a steel pipe which is symmetrically divided into left and right halves along a central axis, and a plurality of steel flower pipes are movably sleeved outside the steel pipe, which are also a two-half structure.

[0007] Furthermore, the steel pipe includes a left half steel pipe and a right half steel pipe, and two fasteners are provided between the left half steel pipe and the right half steel pipe.

[0008] Furthermore, both ends of the left half steel pipe and the right half steel pipe are provided with slots, and the fastener is located between two corresponding slots.

[0009] Further, a hook for clamping with the steel pipe is provided on the inner side wall of the front end of the first steel flower pipe.

[0010] Further, a groove is formed on the outer side wall of the steel pipe, and a clamping block matching the groove is provided on the inner side wall of the steel flower pipe.

[0011] Further, the front end and the rear end of the steel flower pipe are both bevel structures.

[0012] The beneficial effects of the present utility model are as follows: Compared with the prior art, the improvements of the present utility model are as follows.

[0013] 1. The advanced small duct structure of the present utility model can carry out advanced support for cavities or karsts that appear during tunnel construction through the mutual cooperation of the steel pipe and the steel flower pipe. At the same time, grouting can also be carried out into the cavity or karst through the steel pipe to ensure the safety of tunnel construction. In addition, the advanced small duct structure can also be used for cavity filling and grouting reinforcement after the tunnel collapses.

[0014] 2. The advanced small duct structure of the present utility model divides the steel pipe into a split structure, and the two split structures are spliced through fasteners. Under the action of the outer steel flower pipe, they can be spliced together. After the cavity or karst grouting is completed, the fasteners and the steel pipe can be drawn out successively without affecting the steel flower pipe's continuous support function.

[0015] 3. The steel flower pipe in the present utility model is also a split structure. After the inner steel pipe is drawn out, grouting into the steel flower pipe can play a role in reinforcing the surrounding rock. Moreover, when grouting into the steel flower pipe, under the pressure of the grout, the steel flower pipe can be expanded to both sides, further playing a role in reinforcing the rock mass. Description of the Drawings

[0016] Figure 1 It is the front view of the advanced small duct structure of the present utility model.

[0017] Figure 2 It is the side view of the internal structure of the advanced small duct of the present utility model.

[0018] Figure 3 It is the front view of the steel pipe structure of the present utility model.

[0019] Figure 4 It is the side view of the internal structure of the steel pipe of the present utility model.

[0020] Figure 5 It is the front view of the steel flower pipe structure of the present utility model.

[0021] Figure 6 It is the side view of the internal structure of the first steel flower pipe of the present utility model.

[0022] Figure 7Side view of the internal structure of other steel flower pipes except the first one of the present utility model.

[0023] Wherein: 1 - steel pipe, 101 - left half steel pipe, 102 - right half steel pipe, 103 - slotted, 104 - fastener, 2 - steel flower pipe, 3 - hook, 4 - groove, 5 - block. Specific embodiments

[0024] In order to enable those of ordinary skill in the art to better understand the technical solution of the present utility model, the technical solution of the present utility model will be further described below with reference to the drawings and embodiments.

[0025] Refer to the attached Figure 1-7 A pre - advanced small pipe structure for tunnel karst development section shown in the figure, including a steel pipe 1 and a steel flower pipe 2 sleeved outside the steel pipe 1. The steel pipe 1 is symmetrically divided into left and right halves along the central axis, namely a left half steel pipe 101 and a right half steel pipe 102. Slots 103 are provided at both ends of the left half steel pipe 101 and the right half steel pipe 102, and a fastener 104 is provided between the left half steel pipe 101 and the right half steel pipe 102. The fastener 104 contacts but is not connected to the left half steel pipe 101 and the right half steel pipe 102, and the left half steel pipe 101, the right half steel pipe 102 and the two fasteners 104 form a complete circular tubular structure.

[0026] The steel flower pipe 2 is sleeved outside the steel pipe 1, and the length of the steel flower pipe 2 is less than the length of the steel pipe 1. The steel flower pipe 2 is also of a two - half structure. A barbed hook 3 is provided on the inner side wall of the front end of the first steel flower pipe 2. The steel flower pipe 2 can be clamped at the front end of the steel pipe 1 through the hook 3. When the steel pipe 1 and the steel flower pipe 2 are simultaneously inserted into the soil towards the front end, under the action of the hook 3, the steel pipe 1 and the steel flower pipe 2 will not be separated.

[0027] In order to ensure the firm connection between the steel flower pipe 2 and the steel pipe 1, a groove 4 is provided on the outer side wall of the steel pipe 1, and a block 5 is fixedly provided on the inner side wall of the steel flower pipe 2. The block 5 is made of a small steel block and is directly welded and fixed on the inner side wall of the steel flower pipe 2. Through the mutual cooperation of the block 5 and the groove 4, it can be avoided that the steel flower pipe 2 and the steel pipe 1 are separated when they are inserted into the soil towards the front end.

[0028] It should be noted that in the present utility model, the outer diameter of the steel pipe 1 is slightly smaller than the inner diameter of the steel flower pipe 2. When the steel flower pipe 2 is sleeved outside the steel pipe 1, butter is applied between the steel flower pipe 2 and the steel pipe 1, which can not only make them closely fit, but also facilitate the extraction of the steel pipe 1 from the steel flower pipe 2.

[0029] Preferably, in order to ensure the close contact between adjacent two steel flow pipes 2 and prevent them from separating when inserted into the soil, a bevel structure is provided at the end of each steel flow pipe 2. The front end of the steel flow pipe 2 has a bevel structure with a thinner front and a thicker rear, and the rear end has a bevel structure with a thicker front and a thinner rear, so that the front and rear steel flow pipes 2 can be closely fitted without affecting the insertion into the soil.

[0030] Optionally, the steel pipe 1 is generally 4 - 6 meters according to the design value, and the steel flow pipes 2 are arranged in segments, with each segment being 1 meter.

[0031] The advanced small duct structure in this embodiment is specifically applied to the tunnel construction in the karst development section of the tunnel. When it is speculated that there is a cavity or a karst cave ahead, two fasteners 104 are installed together with the left - half steel pipe 101 and the right - half steel pipe 102 to form a complete circular tubular structure; then the first steel flow pipe 2 is clamped at the front end of the steel pipe 1, and the fasteners 104 are fixed to the left - half steel pipe 101 and the right - half steel pipe 102. Butter is applied at the contact positions of the fasteners 104 with the left - half steel pipe 101 and the right - half steel pipe 102.

[0032] The steel pipe 1 and the steel flow pipe 2 are driven into the soil together. For every one - meter deep driving, the next segment of the steel flow pipe 2 is installed around the steel pipe 1. The second and subsequent steel flow pipes 2 are limited in position with respect to the steel pipe 1 through the grooves 4 on the outer sidewall of the steel pipe 1 and the clamping blocks 5 on the inner sidewall of the steel flow pipe 2, and adjacent two steel flow pipes 2 are closely fitted through the bevel structure. When installing the steel flow pipe 2, butter also needs to be applied between the steel flow pipe 2 and the steel pipe 1.

[0033] When the front end of the steel pipe 1 reaches the position inside the cavity or the karst cave, grouting starts into the steel pipe 1. After the grouting is completed, first, the two fasteners 104 are withdrawn from the steel flow pipe 2. After the fasteners 104 are completely withdrawn, the left - half steel pipe 101 and the right - half steel pipe 102 are moved towards each other to disengage the clamping blocks 5 from the grooves 4, and then the left - half steel pipe 101 and the right - half steel pipe 102 are also withdrawn from the steel flow pipe 2; finally, grouting is carried out inside the steel flow pipe 2 to reinforce the surrounding rock mass. Since the steel flow pipe 2 is also a left - and - right split - type structure, when grouting into the steel flow pipe 2, due to the slurry pressure, the steel flow pipe 2 can be pushed open to both sides, playing a role in reinforcing the rock mass.

[0034] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above - mentioned embodiments. What is described in the above - mentioned embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An advanced small conduit structure for a karst development section of a tunnel, comprising a steel pipe (1), characterized in that: The steel pipe (1) is symmetrically divided into left and right halves along the central axis, and a plurality of steel flower pipes (2) are movably sleeved outside the steel pipe (1), and the steel flower pipes (2) are also of a two-half structure.

2. The advanced small conduit structure for the karst development section of a tunnel according to claim 1 is characterized in that: The steel pipe (1) comprises a left half steel pipe (101) and a right half steel pipe (102), and two fasteners (104) are provided between the left half steel pipe (101) and the right half steel pipe (102).

3. The advanced small conduit structure for the karst development section of a tunnel according to claim 2 is characterized in that: Both ends of the left half steel pipe (101) and the right half steel pipe (102) are provided with slots (103), and the fastener (104) is located between two corresponding slots (103).

4. The advanced small conduit structure for the karst development section of a tunnel according to claim 1 is characterized by: A hook (3) for clamping with the steel pipe (1) is provided on the inner side wall of the front end of the first steel flower pipe (2).

5. The advanced small conduit structure for the karst development section of a tunnel according to claim 4 is characterized in that: A groove (4) is provided on the outer side wall of the steel pipe (1), and a clamping block (5) matching the groove (4) is provided on the inner side wall of the steel flower pipe (2).

6. The advanced small conduit structure for the karst development section of a tunnel according to claim 4 is characterized by: The front end and the rear end of the steel flower tube (2) are both inclined structures.

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