Tunnel excavation blasting construction method

Abstract

The tunnel excavation blasting construction method comprises the steps that the edge of the longitudinal cross section of a tunnel is drawn at a tunnel portal, and a tunnel edge line is obtained; grooving in the depth direction of the tunnel along the edge line of the tunnel to obtain an edge groove; reinforcing meshes are installed on the groove walls of the side faces of the edge grooves, a water bag is installed between the two reinforcing meshes, and the water bag is sealed after water is added into the water bag; a plurality of blast holes are formed in the range surrounded by the tunnel edge lines, and explosives are placed in the blast holes; explosive is detonated, cleaning of the tunnel portal is completed, cement concrete mortar is filled between the double-layer reinforcing mesh in the edge groove, and tunnel portal excavation is completed. The double-layer reinforcing mesh is built along the edge of the longitudinal section of the tunnel, and the water bags are added into the double-layer reinforcing mesh to eliminate violence generated during explosive blasting, so that the geological structure outside the tunnel is protected, the situation that the longitudinal section of the tunnel is increased due to too large violence is avoided, and efficient construction is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a tunnel excavation blasting construction method. Background Art

[0002] When constructing a tunnel, it is usually necessary to first excavate the tunnel entrance according to the size of the tunnel. Generally, during excavation, in order to improve the efficiency of excavation, blasting is generally used to excavate the tunnel entrance. The blasting method currently used is to evenly open a number of blasting holes on the plane of the entrance according to the shape of the entrance as the boundary, and then place explosives in the blasting holes, and detonate the explosives to blast the entrance to a certain tunnel depth, and then repair the tunnel wall to complete the excavation of the tunnel at the entrance. Since explosives are used, the original soil layer in the tunnel can be quickly blasted away. Therefore, this method plays an efficient and fast construction role in tunnel excavation.

[0003] Although the use of explosives for blasting can quickly complete the excavation of tunnels, for most geological structures, if explosives are used for blasting, the huge violence of the explosives can easily cause the loosening of the original geological structure and damage the original geological structure, which will damage the tunnel wall. If there are too many blasting holes for explosives or they are distributed too densely, the excessive violence will cause the tunnel wall to be larger than originally expected, which is not conducive to the subsequent construction.

[0004] In summary, when excavating tunnels by placing explosives in blast holes, the distribution of the blast holes is not always just right, which often results in excessive violence due to excessive explosives in the blast holes, thereby causing damage to the geological structure or an increase in the longitudinal cross-section of the tunnel, which requires a large amount of subsequent repairs and reinforcements, which is not conducive to efficient construction. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a tunnel excavation blasting construction method in view of the deficiencies in the above-mentioned prior art, by constructing a double-layer steel mesh along the edge of the longitudinal section of the tunnel, and adding a water bag in the double-layer steel mesh to eliminate the violence generated during the blasting of explosives, thereby protecting the geological structure outside the tunnel, and preventing the longitudinal section of the tunnel from increasing due to excessive violence, which is conducive to efficient construction.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a tunnel excavation blasting construction method, comprising:

[0007] Draw the edge of the longitudinal cross section of the tunnel at the tunnel entrance to obtain the tunnel edge line;

[0008] Grooving along the tunnel edge line in the longitudinal direction of the tunnel to obtain an edge groove;

[0009] A steel mesh is installed on the side wall of the edge groove, and a water bag is placed between two steel meshes. After water is added into the water bag, the water bag is sealed;

[0010] In the range surrounded by the tunnel edge line, a number of blasting holes are respectively set up, and explosives are placed in the blasting holes;

[0011] Detonate the explosives and complete the cleaning of the opening, fill the cement concrete mortar between the double-layer steel mesh in the edge groove, and complete the excavation of the tunnel opening.

[0012] Furthermore, the distance between the two steel meshes is between 10 and 20 centimeters.

[0013] Furthermore, the production of the steel mesh includes:

[0014] Multiple steel bars are interwoven and distributed, and the intersections of the steel bars are welded and fixed to obtain a steel bar straight plate mesh;

[0015] The steel bar mesh is obtained by bending the steel bar straight plate mesh according to the tunnel edge line.

[0016] Furthermore, a wire mesh is also arranged on the mesh of the steel bar straight plate mesh, and the mesh size of the wire mesh is between 3-6 cm.

[0017] Furthermore, a water absorbing layer is provided in the grid of the steel mesh located on the outside.

[0018] Furthermore, after obtaining the tunnel edge line and before grooving along the tunnel edge line in the longitudinal direction of the tunnel, the method further includes:

[0019] Drawing a plurality of separation lines in the area surrounded by the tunnel edge line;

[0020] Grooving along the dividing line in the longitudinal direction of the tunnel to obtain a dividing groove;

[0021] A steel mesh is installed on the side wall of the dividing groove, and a water bag is placed between two steel meshes. After water is added into the water bag, the water bag is sealed.

[0022] Furthermore, the blasting holes are arranged at locations other than edge grooves and separation grooves.

[0023] Furthermore, the distribution of the plurality of separation lines is any one of the following: interlaced distribution or layered distribution.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention provides a tunnel excavation blasting construction method, which includes drawing an edge line along the edge of a longitudinal section of a tunnel, grooving along the edge line to obtain an edge groove, constructing a double-layer steel mesh in the edge groove, adding a water bag in the double-layer steel mesh to eliminate the violence generated during explosive blasting, and finally filling cement concrete mortar between the double-layer steel meshes in the edge groove to ensure the firmness of the tunnel, thereby protecting the geological structure outside the tunnel, and preventing the longitudinal section of the tunnel from increasing due to excessive violence, which is conducive to efficient construction.

[0026] The present invention provides a tunnel excavation blasting construction method, which shares the violence generated by each blasting hole in the tunnel edge line by setting a plurality of dividing lines in the area surrounded by the tunnel edge line and grooving along the dividing lines to obtain dividing grooves, thereby protecting the geological structure outside the tunnel and preventing the longitudinal cross-section of the tunnel from increasing due to excessive violence, which is conducive to efficient construction.

[0027] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention provides a schematic diagram of the overall process of a tunnel excavation and blasting construction method.

[0029] Figure 2 It is a schematic diagram of the distribution structure of the edge grooves and blasting holes in the present invention.

[0030] Figure 3 It is a schematic diagram of the distribution structure of edge grooves, separation grooves and blasting holes in the present invention, wherein the separation grooves are interlaced.

[0031] Figure 4 It is a schematic diagram of the distribution structure of edge grooves, separation grooves and blasting holes in the present invention, wherein the separation grooves are distributed in layers. DETAILED DESCRIPTION

[0032] like Figure 1-4 As shown, the present invention provides a tunnel excavation blasting construction method, such as Figure 1 As shown, it includes the following steps:

[0033] Step 1: Draw the edge of the longitudinal cross section of the tunnel at the tunnel entrance to obtain the tunnel edge line;

[0034] Step 2: Grooving along the tunnel edge line in the longitudinal direction of the tunnel to obtain an edge groove;

[0035] Step 3: Install a steel mesh on the side wall of the edge groove, place a water bag between two steel meshes, add water into the water bag and seal it;

[0036] Step 4: Set up several blasting holes within the range surrounded by the tunnel edge line, and place explosives in the blasting holes;

[0037] Step 5: Detonate the explosives and complete the cleaning of the opening, fill the cement concrete mortar between the double-layer steel mesh in the edge groove, and complete the excavation of the tunnel opening.

[0038] The present invention provides a tunnel excavation blasting construction method, which comprises the following steps: drawing an edge line along the edge of a longitudinal section of a tunnel, slotting along the edge line to obtain an edge groove, constructing a double-layer steel mesh in the edge groove, adding a water bag in the double-layer steel mesh to eliminate the violence generated during the blasting of explosives, and finally filling cement concrete mortar between the double-layer steel meshes in the edge groove to ensure the firmness of the tunnel, thereby protecting the geological structure outside the tunnel, and preventing the longitudinal section of the tunnel from increasing due to excessive violence, which is conducive to efficient construction.

[0039] In step 1, if Figure 2 As shown, the outer incomplete circle is the edge of the longitudinal cross section of the tunnel, and the outermost line is the tunnel edge line.

[0040] In step 2, the edge slot is Figure 2 The shaded part in the figure, the outer side of the edge groove shall not exceed the edge line of the tunnel, and the purpose of the groove is to fill and reinforce. In actual construction, the distance between the two steel meshes is between 10-20 cm. This can not only reinforce the tunnel wall, but also maintain the space inside the tunnel.

[0041] The trenching depth of the edge trench generally depends on the required tunnel depth for the initial excavation. Generally, the tunnel depth for the initial excavation is 1-2 meters.

[0042] In step 3, the edge groove obtained above is filled to reinforce the surface of the tunnel wall. By installing the steel mesh, the steel bar can not only protect the geological structure due to its own toughness, but also isolate the violence of explosives to a certain extent. At the same time, the water bag is set and filled with water to buffer the violence of the explosives. If the violence of the explosives is too great, the water bag will burst. At this time, the water overflows the water bag, which has a greater effect on reducing the explosives. The present invention installs the steel mesh in the edge groove, and also places a water bag in the steel mesh to add water and seal it, so that a great force is generated during the blasting, preventing the violence of the blasting from rushing through the edge of the tunnel, and forming a protective film for the tunnel. The geological structure outside the tunnel is protected, and the longitudinal section of the tunnel will not increase due to excessive violence, which is conducive to efficient construction.

[0043] The production of steel mesh includes:

[0044] Multiple steel bars are interwoven and distributed, and the intersections of the steel bars are welded and fixed to obtain a steel bar straight plate mesh;

[0045] The steel bar mesh is obtained by bending the steel bar straight plate mesh according to the tunnel edge line.

[0046] Among them, in order to further strengthen the protection of the steel mesh outside the tunnel, the engineers use finer meshes, so that when preventing blasting, more violence can be dispersed and eliminated. Therefore, in the present invention, a wire mesh is also provided on the mesh of the steel straight plate mesh, and the mesh size of the wire mesh is between 3-6 cm.

[0047] At the same time, in order to prevent the water bag from rupturing and water resources from overflowing during blasting, the present invention provides a water absorbing layer in the mesh of the steel mesh located on the outside, so that the water source will not penetrate into the geological structure outside the tunnel.

[0048] In the present invention, after step 2 and before step 3, that is, after obtaining the tunnel edge line and before grooving along the tunnel edge line in the longitudinal direction of the tunnel, the method further includes:

[0049] Drawing a plurality of separation lines in the area surrounded by the tunnel edge line;

[0050] Grooving along the dividing line in the longitudinal direction of the tunnel to obtain a dividing groove;

[0051] A steel mesh is installed on the side wall of the dividing groove, and a water bag is placed between two steel meshes. After water is added into the water bag, the water bag is sealed.

[0052] The present invention provides a tunnel excavation blasting construction method, which shares the violence generated by each blasting hole in the tunnel edge line by setting a plurality of dividing lines in the area surrounded by the tunnel edge line and grooving along the dividing lines to obtain dividing grooves, thereby protecting the geological structure outside the tunnel and preventing the longitudinal cross-section of the tunnel from increasing due to excessive violence, which is conducive to efficient construction.

[0053] It can be seen from the above that the dividing grooves in the present invention also play a role in dispersing and eliminating the violence of blasting. For the sake of construction safety, the blasting holes need to be set in non-edge grooves and non-dividing grooves, that is, the blasting holes are set in non-edge grooves and non-dividing grooves.

[0054] In addition, the distribution of the plurality of separation lines is any one of the following: Figure 3 The interlaced distribution shown or Figure 4 The stratified distribution is shown. Figure 3 and Figure 4In the figure, the dotted line represents the dividing groove, which is drawn by on-site construction workers based on the geological structure of the site.

[0055] In step 4, the tunnel is drilled and charged to prepare for blasting. The selection of explosives and drilling requires workers to operate in a conventional manner. The depth of the drilling is also determined according to the depth required for the initial excavation of the tunnel, which is generally 10-20 cm less than the depth required for the initial excavation of the tunnel.

[0056] In step 5, after the blasting is completed, the water bag is taken out, the site after the blasting is cleaned, and cement concrete mortar is filled between the double-layer steel mesh in the edge groove. Since the steel bars are wrapped in the mortar, anchor rods need to be inserted into the geological structure outside the tunnel to fix the cement mortar between the double-layer steel mesh in the edge groove, thereby ensuring the solidity of the tunnel.

[0057] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A tunnel excavation blasting construction method, characterized in that: include: Draw the edge of the longitudinal cross section of the tunnel at the tunnel entrance to obtain the tunnel edge line; Grooving along the tunnel edge line in the longitudinal direction of the tunnel to obtain an edge groove; A steel mesh is installed on the side wall of the edge groove, and a water bag is placed between two steel meshes. After water is added into the water bag, the water bag is sealed; In the range surrounded by the tunnel edge line, a number of blasting holes are respectively set up, and explosives are placed in the blasting holes; Detonate the explosives and complete the cleaning of the opening, fill the space between the double-layer steel mesh in the edge groove with cement concrete mortar to complete the excavation of the tunnel opening.

2. A tunnel excavation blasting construction method according to claim 1, characterized in that: The distance between the two steel meshes is between 10 and 20 centimeters.

3. A tunnel excavation blasting construction method according to claim 1, characterized in that: The production of the steel mesh includes: Multiple steel bars are interwoven and distributed, and the intersections of the steel bars are welded and fixed to obtain a steel bar straight plate mesh; The steel bar mesh is obtained by bending the steel bar straight plate mesh according to the tunnel edge line.

4. A tunnel excavation blasting construction method according to claim 3, characterized in that: A wire mesh is also arranged on the mesh of the steel bar straight plate mesh, and the mesh size of the wire mesh is between 3-6 cm.

5. A tunnel excavation blasting construction method according to claim 1, characterized in that: A water absorbing layer is arranged in the mesh of the steel mesh located on the outside.

6. A tunnel excavation blasting construction method according to claim 1, characterized in that: After obtaining the tunnel edge line and before grooving along the tunnel edge line in the longitudinal direction of the tunnel, the method further includes: Drawing a plurality of separation lines in the area surrounded by the tunnel edge line; Grooving along the dividing line in the longitudinal direction of the tunnel to obtain a dividing groove; A steel mesh is installed on the side wall of the dividing groove, and a water bag is placed between two steel meshes. After water is added into the water bag, the water bag is sealed.

7. A tunnel excavation blasting construction method according to claim 6, characterized in that: The blasting holes are arranged at locations other than edge grooves and separation grooves.

8. A tunnel excavation blasting construction method according to claim 6, characterized in that: The distribution mode of the plurality of separation lines is any one of the following: interlaced distribution or layered distribution.

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