Connection channel excavation method for water-rich weathered rock stratum

Abstract

The invention discloses a method for excavating a connecting channel for a water-rich weathered rock stratum, which comprises the following steps of: respectively constructing water stop hoops at opening design positions of the connecting channel on two tunnel segments, so that each water stop hoop covers the periphery of the corresponding tunnel segment; a pipe shed is constructed above the design position of the connecting channel, and the two ends of the pipe shed are connected to the two tunnel segments through the water stop hoops respectively; curtain grouting is carried out within the design range of the connection channel between the two tunnel segments so as to reinforce the to-be-excavated soil body; constructing a drainage hole in a design range of a connection channel between the two tunnel segments to collect leakage water in the design range of the connection channel, so that the drainage hole is obliquely arranged, the end with the lower elevation is communicated with the tunnel segment at the excavation terminal end, and the end with the higher elevation extends to the tunnel segment at the excavation starting end; by means of the excavation method, the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to a method for excavating a connecting passage in a water-rich weathered rock stratum. Background Art

[0002] Urban subways consist of stations and sections. The sections are mostly constructed by the shield method and usually consist of two main tunnels, an up-line tunnel and a down-line tunnel. Due to the long length of the section, a connecting passage is generally set in the middle of the section as a transverse passage for connecting the two main tunnels. In the weathered rock stratum section, the connecting passage is generally excavated and constructed by the mining method. However, groundwater is common in southern cities, and a large amount of groundwater will remain in the cracks of the weathered rock stratum. Therefore, when the traditional mining method is used to excavate the connecting passage, it is easy to cause the collapse of the vault and the water gushing at the heading face, which will further lead to problems such as excessive surface settlement and collapse. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a method for excavating a connecting passage in a water-rich weathered rock stratum, which ensures the stability of the excavation of the connecting passage, avoids water gushing, and improves the construction efficiency at the same time.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is a method for excavating a connecting passage in a water-rich weathered rock stratum, including the steps:

[0005] Step 1: Construct water-stop collar rings at the designed opening positions of the connecting passage on the two tunnel segments respectively, so that each water-stop collar ring covers the outer periphery of the corresponding tunnel segment and covers the designed opening position of the connecting passage;

[0006] Step 2: Construct a pipe shed above the designed position of the connecting passage, so that the two ends of the pipe shed are respectively connected to the two tunnel segments through the water-stop collar rings;

[0007] Step 3: Conduct curtain grouting within the designed range of the connecting passage between the two tunnel segments to reinforce the soil to be excavated;

[0008] Step 4: Construct drainage holes within the designed range of the connecting passage between the two tunnel segments to collect the seepage water within the designed range of the connecting passage, so that the drainage holes are inclined and the lower end with a lower elevation is communicated with the tunnel segment at the excavation end point, and the higher end extends towards the tunnel segment at the excavation starting point;

[0009] Step 5: Excavate the connecting passage.

[0010] The improvement of the method for excavating a connecting passage in a water-rich weathered rock stratum of the present invention is further that when implementing the above Step 1, when constructing the water-stop collar ring, at least two rings of tunnel segments on both the left and right sides of the designed opening position of the connecting passage are covered.

[0011] A further improvement of the excavation method for the cross-passage in water-rich weathered rock strata of the present invention lies in that when performing the above-mentioned step 2, holes are drilled at intervals above the designed position of the cross-passage to form holes, so that a plurality of the holes are arranged in rows and are all communicated with the two tunnel segments, and then pipe fittings are inserted into each of the holes to form the pipe shed.

[0012] A further improvement of the excavation method for the cross-passage in water-rich weathered rock strata of the present invention lies in that a plurality of slurry outlet holes are arranged at intervals along the axial direction on the outer periphery of each of the pipe fittings. After each of the pipe fittings is inserted in place, pressure grouting is carried out into each of the pipe fittings to reinforce the soil body between adjacent pipe fittings.

[0013] A further improvement of the excavation method for the cross-passage in water-rich weathered rock strata of the present invention lies in that when performing the above-mentioned step 3, when carrying out the curtain grouting, the grouting range is expanded to at least 3 m outside the designed range of the cross-passage.

[0014] A further improvement of the excavation method for the cross-passage in water-rich weathered rock strata of the present invention lies in that when performing the above-mentioned step 4, a plurality of the drainage holes are arranged at intervals in the horizontal direction within the designed position of the cross-passage, and a water receiving bucket is placed at the position corresponding to each of the drainage holes in the tunnel segment at the excavation end.

[0015] A further improvement of the excavation method for the cross-passage in water-rich weathered rock strata of the present invention lies in that before performing the above-mentioned step 5 and after performing the above-mentioned step 4, exploration hole construction is carried out at the designed opening position of the cross-passage in the tunnel segment at the excavation starting end. After the water stop effect meets the design requirements, the above-mentioned step 5 is then performed.

[0016] A further improvement of the excavation method for the cross-passage in water-rich weathered rock strata of the present invention lies in that when performing the above-mentioned step 5, the cross-passage is excavated by the bench method.

[0017] Compared with the prior art, the advantages of the present invention are as follows:

[0018] 1. It can effectively control the risk of water seepage and water gushing during the excavation of the cross-passage in the water-rich weathered rock stratum, which is beneficial to ensuring the construction safety of the cross-passage.

[0019] 2. It controls the risk of water loss in the surrounding strata during the excavation of the cross-passage, which is beneficial to reducing the risks of water leakage and quicksand, and is beneficial to controlling the ground settlement and collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the attached drawings required for the description of the embodiments. Obviously, the attached drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other attached drawings can be obtained based on these attached drawings.

[0021] Figure 1 It is the construction completed side view of the water stop collar of the present invention.

[0022] Figure 2 It is the construction completed sectional view of the water stop collar of the present invention.

[0023] Figure 3 It is the construction completed front view of the pipe shed of the present invention.

[0024] Figure 4 It is the construction completed sectional view of the pipe shed of the present invention.

[0025] Figure 5 It is the construction completed front view of the curtain grouting of the present invention.

[0026] Figure 6 It is the construction completed sectional view of the curtain grouting of the present invention.

[0027] Figure 7 It is the construction completed front view of the drainage hole of the present invention.

[0028] Figure 8 It is the construction completed sectional view of the drainage hole of the present invention.

[0029] In the figure: 1, tunnel segment; 2, water stop collar; 3, opening; 4, connection passage; 5, pipe shed; 6, reinforced soil mass; 7, drainage hole. Specific embodiments

[0030] The following illustrates the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0031] The following further details the method for excavating the connection passage for the water-rich weathered rock stratum of the present invention in conjunction with the attached drawings and specific embodiments.

[0032] Please refer to Figures 1 to 8 As shown, the method for excavating the connection passage for the water-rich weathered rock stratum includes the steps:

[0033] Step 1: Construct water stop collars 2 at the designed positions of the openings 3 of the connection passage 4 on two tunnel segments 1 respectively, so that each water stop collar 2 covers the outer periphery of the corresponding tunnel segment 1 and covers the designed positions of the openings 3 of the connection passage 4;

[0034] Step 2: Construct a pipe shed 5 above the designed position of the connection passage 4, so that both ends of the pipe shed 5 are connected to the two tunnel segments 1 through the water stop collars 2;

[0035] Step 3: Conduct curtain grouting at the position within the designed range of the connection passage 4 between the two tunnel segments 1 to reinforce the soil to be excavated;

[0036] Step 4: Construct drain holes 6 at the position within the designed range of the connection passage 4 between the two tunnel segments 1 to collect the seepage water within the designed range of the connection passage 4, so that the drain holes 6 are inclined and the lower end with a lower elevation is communicated with the tunnel segment 1 at the excavation end point, and the higher end extends towards the tunnel segment 1 at the excavation starting point;

[0037] Step 5: Excavate the connection passage 4.

[0038] Reinforced soil mass 6 is formed through curtain grouting, which is convenient for subsequent excavation of the connection passage 4.

[0039] By setting the drain holes 6, drainage is carried out in advance before excavation to reduce the water head pressure and ensure the safety of subsequent excavation construction.

[0040] Specifically, when performing the above Step 3, during curtain grouting, when the water content at the designed position of the connection passage 4 is relatively large, quick-setting cement-sodium silicate double-fluid grout is used for grouting, and when the water content at the designed position of the connection passage 4 is relatively small, ordinary cement neat slurry can be used for grouting.

[0041] Preferably, when performing the above Step 1, when constructing the water stop collars 2, at least two rings of segments on both the left and right sides of the designed position of the opening 3 of the connection passage 4 are covered.

[0042] Specifically, when performing the above Step 1, through the grouting holes on the tunnel segment 1 itself, quick-setting cement-sodium silicate double-fluid grout is injected from the inside to the outside to form the water stop collars 2.

[0043] By using the quick-setting cement-sodium silicate double-fluid grout, the cracks in the weathered rock formation can be quickly sealed, the water collecting channels can be quickly cut off, and the groundwater around can be reduced from converging to the opening 3 of the connection passage 4.

[0044] Preferably, when performing the above Step 2, first drill holes at intervals above the designed position of the connection passage 4 to form holes, so that multiple holes are arranged in a row and are all communicated with the two tunnel segments 1, and then insert pipe fittings into each hole to form the pipe shed 5.

[0045] Specifically, the orthographic projection of the pipe shed 5 completely covers the orthographic projection of the connecting passage 4.

[0046] By restricting the orthographic projection range of the segment, it is ensured that the connecting passage 4 is completely covered by the pipe shed 5, preventing the collapse of the top soil during the subsequent excavation of the connecting passage 4.

[0047] Preferably, a plurality of grout holes are arranged at intervals along the axial direction on the outer periphery of each pipe fitting. After each pipe fitting is inserted in place, pressure grouting is carried out into each pipe fitting to reinforce the soil between adjacent pipe fittings.

[0048] By pressurized grouting into the pipe fitting, it is ensured that the grout will spray out through the multiple grout holes on the pipe fitting and reinforce the soil between adjacent pipe fittings, and also play a role in sealing water at the vault.

[0049] Preferably, when performing the above step 3, during the curtain grouting, the grouting range is expanded to at least 3 m outside the design range of the connecting passage 4.

[0050] By expanding the range of the curtain grouting, the range of the reinforced soil mass 6 is further expanded, further improving the stability of the subsequent excavation of the connecting passage 4.

[0051] Preferably, when performing the above step 4, a plurality of drain holes 6 are arranged at intervals in the horizontal direction within the design position range of the connecting passage 4, and a water receiving bucket is placed at the position corresponding to each drain hole 6 in the tunnel segment 1 at the excavation end.

[0052] Specifically, the opening position of the drain hole 6 is located at the lower part within the design range of the connecting passage 4.

[0053] The groundwater within the design position of the connecting passage 4 will automatically seep downward due to its own gravity, and part of it will enter the drain hole 6. Since the drain hole 6 is inclined, the water in the drain hole 6 will flow along the drain hole 6 and be discharged into the water receiving bucket.

[0054] Preferably, before performing the above step 5 and after performing the above step 4, exploratory hole construction is carried out at the design position of the opening 3 of the connecting passage 4 in the tunnel segment 1 at the excavation starting end. After the water sealing effect meets the design requirements, the above step 5 is then performed.

[0055] Preferably, when performing the above step 5, the connecting passage 4 is excavated by the bench method.

[0056] Specifically, when excavating the connecting passage 4, support and lining construction are carried out synchronously.

[0057] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the implementation conditions of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the ratio relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear narration, and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0058] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not used to limit the present invention. Any person skilled in the art, without departing from the technical solution of the present invention, can make some changes or modifications to the equivalent embodiments of equivalent changes by using the technical content disclosed above. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for excavating a communication channel in a water-rich weathered rock formation, characterized in that: Includes steps: Step 1: construct water stop ring hoops at the opening design positions of the communication channels on the two tunnel segments respectively, so that each of the water stop ring hoops is wrapped around the outer periphery of the corresponding tunnel segment and covers the opening design position of the communication channel; Step 2: constructing a pipe shed above the designed position of the communication channel, so that both ends of the pipe shed are respectively connected to the two tunnel segments through the water stop ring; Step 3: Perform curtain grouting within the design range of the communication channel between the two tunnel segments to reinforce the soil to be excavated; Step 4: constructing a drainage hole within the design range of the communication channel between the two tunnel segments to collect the leakage water within the design range of the communication channel, so that the drainage hole is inclined and the lower end is connected to the tunnel segment at the end of the excavation, and the higher end extends to the tunnel segment at the starting end of the excavation; Step 5: Dig the communication channel.

2. The method for excavating a communication channel in a water-rich weathered rock formation according to claim 1, characterized in that: When executing the above step 1, when constructing the water stop ring hoop, at least two ring segments on both sides of the opening design position of the communication channel are covered.

3. The method for excavating a communication channel for a water-rich weathered rock formation according to claim 1, characterized in that: When executing the above step 2, holes are first drilled at intervals above the designed position of the connecting channel to form holes, so that multiple holes are arranged in rows and all connect the two tunnel segments, and then pipes are inserted into each hole to form the pipe rack.

4. The method for excavating a communication channel for a water-rich weathered rock formation according to claim 3, characterized in that: The outer circumference of each pipe is provided with a plurality of grouting holes spaced apart in the axial direction. After each pipe is inserted in place, pressure grouting is performed into each pipe to reinforce the soil between adjacent pipes.

5. The method for excavating a communication channel for a water-rich weathered rock formation according to claim 1, characterized in that: When executing the above step 3, when performing curtain grouting, the grouting range is expanded to at least 3m outside the design range of the communication channel.

6. The method for excavating a communication channel in a water-rich weathered rock formation according to claim 1, characterized in that: When executing the above step 4, a plurality of drainage holes are opened at intervals in the horizontal direction within the designed position of the communication channel, and a water collecting bucket is placed at the position corresponding to each drainage hole in the tunnel segment at the end of the excavation.

7. The method for excavating a communication channel in a water-rich weathered rock formation according to claim 1, characterized in that: Before executing the above step 5 and after executing the above step 4, exploratory hole construction is carried out at the opening design position of the connecting channel in the tunnel segment at the excavation starting end, and the above step 5 is executed after the water-stopping effect meets the design requirements.

8. The method for excavating a communication channel in a water-rich weathered rock formation according to claim 1, characterized in that: When executing step 5 above, the connecting channel is excavated using the step method.

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