Main hole reinforcing method suitable for broken surrounding rock tunnel vehicle-traveling transverse hole construction

Abstract

The invention discloses a main hole reinforcing method suitable for broken surrounding rock tunnel vehicle-traveling transverse hole construction, which comprises the following steps: excavating a first and / or second main hole to a first position which is positioned in front of the intersection of the vehicle-traveling transverse hole and the first and / or second main hole, at least one steel stand column is arranged between the first position and the vehicle transverse hole; the first main hole and / or the second main hole continue to be excavated to a second position, and after the second position is located at the intersection of the vehicle transverse hole and the first main hole and / or the second main hole, at least one steel stand column is arranged between the vehicle transverse hole and the second position; and after the first main hole and the second main hole are supported, the vehicle-traveling transverse hole is excavated. The working procedures are clear and definite, and the construction technology for the intersection of the current transverse tunnel and the main tunnel is perfected and supplemented.

Description

Technical Field

[0001] The invention is applicable to the design and construction of dark-digging tunnels, and is particularly applicable to temporary reinforcement of a main tunnel when constructing a vehicle-carrying cross tunnel under broken surrounding rock conditions. Background Art

[0002] Tunnel engineering is currently developing in the direction of larger cross-sections, deeper burial depths, and longer distances. The tunnel cross tunnel is an important path for vehicle evacuation and rescue in the tunnel, and is an important part of the tunnel engineering. The intersection of the cross tunnel and the main tunnel is a weak link in tunnel construction, especially the construction of the cross tunnel in the broken surrounding rock section, which is prone to cause deformation and cracking of the initial support of the main tunnel, and is a high-incidence section for safety accidents in tunnel engineering.

[0003] There have been many studies on the construction of vehicle-carrying cross tunnels in the field of tunnel engineering. The research directions are mainly focused on the reinforcement of the initial support of the intersection and the secondary lining. For example, the initial support is mostly strengthened by means of portal frames and locking anchors, and the secondary lining is mostly strengthened by setting thickened transition sections and increasing reinforcement. The current research is less about how to prevent the deformation and cracking of the initial support of the main tunnel during the construction of the vehicle-carrying cross tunnel. According to the investigation, this key link is relatively arbitrary in the actual construction process, and it is very easy to cause large deformation and cracking in the broken surrounding rock, which poses a great safety hazard. Summary of the invention

[0004] The present invention aims to provide a main tunnel reinforcement method suitable for the construction of a vehicle-passing cross tunnel in a broken surrounding rock tunnel, which can effectively improve the safety of cross passage construction at tunnel intersections and prevent cracking of the initial support of the main tunnel caused by the construction of the vehicle-passing cross tunnel.

[0005] According to one aspect of the present invention, there is provided a method for reinforcing a main tunnel suitable for the construction of a vehicle tunnel in a broken surrounding rock tunnel, comprising: excavating a first and / or second main tunnel to a first position, the first position being located before the intersection of the vehicle tunnel and the first and / or the second main tunnel, and at least one steel column being arranged between the first position and the vehicle tunnel; continuing to excavate the first and / or the second main tunnel to a second position, the second position being located after the intersection of the vehicle tunnel and the first and / or the second main tunnel, and at least one steel column being arranged between the vehicle tunnel and the second position; and excavating the vehicle tunnel after the initial support of the first main tunnel and the second main tunnel is completed.

[0006] Preferably, the first position is located 10 meters before the intersection of the vehicle cross tunnel and the first and / or the second main tunnel.

[0007] Preferably, the second position is located 10 meters behind the intersection of the vehicle cross tunnel and the first and / or the second main tunnel.

[0008] Preferably, both ends of the steel column are respectively supported on the bottom and top supports of the first and / or second main holes.

[0009] Preferably, the steel column is a steel support with a diameter of 800 and a longitudinal spacing of 3-5m. Square timber is arranged at the connection between the steel column and the first and / or the second main hole for isolation and force transmission.

[0010] Preferably, excavating the first and / or second main tunnel includes dividing the tunnel cross-section into an upper step, a middle step and a lower step, wherein the upper step, the middle step and the lower step respectively include a mechanical excavation area adjacent to the tunnel contour line and a blasting excavation area separated from the tunnel contour line by the mechanical excavation area.

[0011] Preferably, the mechanical excavation area of ​​the upper step is excavated until the excavation cross-sectional size of the upper step is reached; the blasting excavation area of ​​the upper step is excavated until the excavation cross-sectional size of the upper step is reached; and the mechanical excavation area and blasting excavation area of ​​the middle step and the lower step are excavated in sequence according to the same steps.

[0012] Preferably, excavating the blasting excavation area in the stage of going up to the platform includes the following steps: determining the arrangement of blastholes according to construction requirements; drilling according to the arrangement of blastholes; removing the gravel in the blastholes after the drilling process is completed; and charging and blasting.

[0013] Preferably, one end of the steel column is supported on the support at the top of the first and / or the second main hole, and the other end is supported on the horizontal plane of the upper step, the middle step or the lower step.

[0014] Preferably, determining the hole arrangement plan of the blast holes also includes setting slot holes, auxiliary holes, blast holes, peripheral holes, and bottom plate holes in the blasting excavation area.

[0015] Since the reinforcement of the main tunnel at the intersection of the vehicle cross tunnel and the main tunnel is a construction safety measure, the tunnel civil engineering design drawings do not make targeted designs for the reinforcement of the main tunnel. This key link is relatively arbitrary during actual construction, and there are major safety hazards. The present invention provides a main tunnel reinforcement method suitable for the construction of a vehicle cross tunnel in the broken surrounding rock section of a tunnel, which can effectively improve the safety of the construction of the vehicle cross tunnel at the intersection of the tunnel and prevent the initial support cracking of the main tunnel caused by the construction of the vehicle cross tunnel. The process of the present invention is clear and definite, and it is an improvement and supplement to the current construction process at the intersection of the vehicle cross tunnel and the main tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: 1. Main tunnel, 2. Vehicle tunnel, 3. Initial support of main tunnel, 4. Φ800 steel support, 5. Initial support of vehicle tunnel, 6. Excavation steps, 7. Tunnel excavation direction. Among them,

[0017] Figure 1 is a schematic plan view of a main hole reinforcement according to an embodiment of the present invention;

[0018] Figure 2 is a schematic cross-sectional view of a main hole reinforcement according to an embodiment of the present invention;

[0019] Figure 3 is a schematic longitudinal section diagram of a main hole reinforcement according to an embodiment of the present invention; and

[0020] Figure 4 It is a schematic diagram of a longitudinal section of a main hole reinforcement according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] Figure 1 Schematic diagram of a main hole reinforcement plane according to an embodiment of the present invention. Figure 1 As shown, a method for reinforcing a main tunnel suitable for the construction of a vehicle-carrying cross tunnel in a broken surrounding rock tunnel comprises: excavating a main tunnel 1 to a first position, the main tunnel 1 may include a first main tunnel and / or a second main tunnel, the first position is located before the intersection of the vehicle-carrying cross tunnel and the first and / or the second main tunnel, Figure 1 The excavation direction of the middle tunnel is the direction indicated by the arrow, so the first position is below the vehicle tunnel 2. It should be noted that the left, right, up and down here are only for the directions in the attached drawings and do not constitute a specific limitation of the present invention. At least one steel column 4 is set between the first position and the vehicle tunnel; continue to excavate the first and / or the second main tunnel to the second position, and the second position is located at the intersection of the vehicle tunnel and the first and / or the second main tunnel. It is also noted that due to Figure 1 The excavation direction of the middle tunnel is the direction indicated by arrow 7, so the second position is above the vehicle tunnel 2. It should be noted that the left, right, up and down here are only for the directions in the attached drawings and do not constitute a specific limitation of the present invention. At least one steel column 4 is set between the vehicle tunnel and the second position; after the initial support of the first main tunnel and the second main tunnel is completed, the vehicle tunnel is excavated.

[0023] According to an embodiment of the present invention, the excavation order of the first main hole and the second main hole is not specifically limited. The first main hole and the second main hole can be excavated at the same time, or the first main hole can be excavated first and then the second main hole.

[0024] The first and / or second main tunnel is excavated to a first position, the first position is located before the intersection of the vehicle transverse tunnel and the first and / or the second main tunnel, and at least one steel column is set between the first position and the vehicle transverse tunnel. The preferred scheme of this embodiment is to first excavate the first and / or second main tunnel, and when the excavation reaches the first position, the main tunnel is excavated and the steel column is set at the same time until the main tunnel is excavated to the intersection of the vehicle transverse tunnel and the main tunnel.

[0025] Continue to excavate the first and / or second main tunnel to a second position, and after the second position is located at the intersection of the vehicle transverse tunnel and the first and / or second main tunnel, at least one steel column is set between the vehicle transverse tunnel and the second position. The preferred solution of this embodiment is to continue to excavate the main tunnel after setting at least one steel column between the first position and the vehicle transverse tunnel, and to excavate the main tunnel and set the steel column at the same time until the main tunnel is excavated to the second position.

[0026] After the initial support of the first main tunnel and the second main tunnel is completed, the vehicle cross tunnel is excavated. The first position is located 10 meters before the intersection of the vehicle cross tunnel and the first and / or the second main tunnel. The second position is located 10 meters after the intersection of the vehicle cross tunnel and the first and / or the second main tunnel. The two ends of the steel column are respectively supported by the bottom and top supports of the first and / or the second main tunnel. The steel column is a steel support with a diameter of 800 and a longitudinal spacing of 3-5m. Square timber is set at the connection between the steel column and the first and / or the second main tunnel for isolation and force transmission.

[0027] Excavating the first and / or second main tunnel includes dividing the tunnel cross section into an upper step, a middle step and a lower step, wherein the upper step, the middle step and the lower step respectively include a mechanical excavation area adjacent to the tunnel contour line and a blasting excavation area separated from the tunnel contour line by the mechanical excavation area.

[0028] At present, the commonly used excavation methods for mining tunnels are mainly divided into two categories: mechanical method and drilling and blasting method, which have different characteristics and applicability. The mechanical method is a method of excavating tunnels using mechanical tools such as single-suspension tunnel boring machines and milling machines. Its characteristics are low vibration, low noise, small disturbance to the surrounding rock, and good control of tunnel over-excavation and under-excavation; but its disadvantages are expensive equipment, large wear of hard rock drill bits, low hard rock excavation efficiency, and high construction cost. The drilling and blasting method is a method of excavating tunnels by drilling, charging, and blasting. This method has evolved from the early days of manually drilling holes with a drill and hammer, and using detonators to detonate individual explosive packs one by one, to drilling holes with a rock drilling rig or a multi-arm drilling rig, and applying blasting technologies such as millisecond blasting, pre-splitting blasting, and smooth blasting. Its characteristics are a wide range of applications, applicable to both soft and medium hard rocks, high rock breaking efficiency, fast construction progress, and low cost. It is currently the main method of tunnel construction in my country; but its disadvantage is that during construction, due to various factors such as human and equipment, it is difficult to control tunnel over-excavation and under-excavation.

[0029] According to the embodiments provided by the present invention, requirements such as construction progress, cost, and tunnel over-break and under-break control can be met at the same time.

[0030] Excavate the mechanical excavation area of ​​the upper step until the excavation cross-sectional size of the upper step is reached; excavate the blasting excavation area of ​​the upper step until the excavation cross-sectional size of the upper step is reached; and excavate the mechanical excavation area and blasting excavation area of ​​the middle step and the lower step in sequence according to the same steps.

[0031] Excavating the blasting excavation area in the stage of going up to the platform includes the following steps: determining the arrangement of blastholes according to construction requirements; drilling according to the arrangement of blastholes; removing the gravel in the blastholes after the drilling process is completed; and charging and blasting.

[0032] One end of the steel column is supported on the support at the top of the first and / or second main hole, and the other end is supported on the horizontal plane of the upper step, the middle step or the lower step.

[0033] The hole arrangement plan for determining the blastholes also includes setting slot holes, auxiliary holes, blastholes, peripheral holes, and bottom plate holes in the blasting excavation area.

[0034] Since the reinforcement of the main tunnel at the intersection of the vehicle cross tunnel and the main tunnel is a construction safety measure, the tunnel civil engineering design drawings do not make targeted designs for the reinforcement of the main tunnel. This key link is relatively arbitrary during actual construction, and there are major safety hazards. The present invention provides a main tunnel reinforcement method suitable for the construction of a vehicle cross tunnel in the broken surrounding rock section of a tunnel, which can effectively improve the safety of the construction of the vehicle cross tunnel at the intersection of the tunnel and prevent the initial support cracking of the main tunnel caused by the construction of the vehicle cross tunnel. The process of the present invention is clear and definite, and it is an improvement and supplement to the current construction process at the intersection of the vehicle cross tunnel and the main tunnel.

[0035] The following examples are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the following description, and these various changes, modifications, substitutions and deformations derived from the principles and spirit of the present invention still fall within the scope of protection of the present invention.

[0036] The present invention discloses a main tunnel reinforcement method suitable for the construction of a vehicle-carrying cross tunnel in a broken surrounding rock tunnel. Figures 1 to 4 As shown, before the construction of the cross tunnel, the steel columns are pre-reinforced within 10m before and after the intersection of the cross tunnel 2 and the main tunnel 1, which mainly includes the following construction steps:

[0037] (1) The main tunnel is excavated using the step method to the intersection of the vehicle cross tunnel 2 and the main tunnel 1. Multiple steel columns are set within 10m before the intersection. The ends of the columns are firmly supported by the support 3 at the bottom and top of the main tunnel;

[0038] (2) It is recommended that the steel column 4 be supported by a steel support with a diameter of 800, with a longitudinal spacing of 3-5m, and that square timber and other materials be installed at the connection between the steel column 4 and the initial support 3 for isolation and force transmission;

[0039] (3) Continue to excavate the main tunnel 1. To facilitate the construction of the vehicle cross tunnel 2, no steel columns may be installed in the area of ​​the main tunnel 1 directly opposite the vehicle cross tunnel 2;

[0040] (4) Multiple steel columns 4 are set within 10m behind the intersection, and the ends of the columns are firmly supported by the supports 3 at the bottom and top of the main tunnel;

[0041] (5) If the main tunnel 1 is still in the excavation state within 10m of the intersection during the construction of the vehicle tunnel 2, the steel column 4 can also be supported between the step horizontal surface 6 and the top support 3, and the vehicle tunnel support 5 can also be set up in the vehicle tunnel 2;

[0042] (6) Excavation of the vehicle-carrying cross tunnel can only be carried out after the steel columns of the main tunnels of the left and right tunnels have been reinforced.

[0043] The invention can effectively improve the safety of cross-channel construction at the tunnel intersection and prevent the cracking of the initial support of the main tunnel caused by the construction of the vehicle cross-tunnel in the broken surrounding rock section. The process of the invention is clear and definite, which is a perfection and supplement to the current construction process at the intersection of the vehicle cross-tunnel and the main tunnel.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for reinforcing the main tunnel of a broken rock tunnel for vehicle traffic, characterized in that: include: Excavating the first and / or second main tunnel to a first position, wherein the first position is located before the intersection of the vehicle cross tunnel and the first and / or second main tunnel, and at least one steel column is arranged between the first position and the vehicle cross tunnel; Continue to excavate the first and / or second main tunnel to a second position, wherein the second position is located at the intersection of the vehicle transverse tunnel and the first and / or second main tunnel, and then at least one steel column is arranged between the vehicle transverse tunnel and the second position; After the support of the first main tunnel and the second main tunnel is completed, the vehicle cross tunnel is excavated.

2. The method according to claim 1, characterized in that The first position is located 10 meters before the intersection of the vehicle cross tunnel and the first and / or the second main tunnel.

3. The method according to claim 1, characterized in that The second position is located 10 meters behind the intersection of the vehicle cross tunnel and the first and / or the second main tunnel.

4. The method according to claim 1, characterized in that: The two ends of the steel column are respectively supported on the bottom and top supports of the first and / or second main holes.

5. The method according to claim 1, characterized in that The steel columns are steel supports with a diameter of 800 and a longitudinal spacing of 3-5m. Square timbers are arranged at the connection between the steel columns and the first and / or the second main holes for isolation and force transmission.

6. The method according to claim 1, characterized in that Excavation of the first and / or second main holes, including: The tunnel cross section is divided into an upper step, a middle step and a lower step, wherein the upper step, the middle step and the lower step respectively include a mechanical excavation area adjacent to the tunnel contour line and a blasting excavation area separated from the tunnel contour line by the mechanical excavation area.

7. The method according to claim 6, characterized in that Excavate the mechanical excavation area of ​​the upper step until the excavation cross-sectional size of the upper step is reached; excavate the blasting excavation area of ​​the upper step until the excavation cross-sectional size of the upper step is reached; and excavate the mechanical excavation area and blasting excavation area of ​​the middle step and the lower step in sequence according to the same steps.

8. The method according to claim 7, characterized in that Excavating the blasting excavation area in the stage of stepping up includes the following steps: Determine the blasthole layout plan based on construction requirements; Drilling according to the blasthole arrangement plan; After the drilling process is completed, the debris in the blasthole is removed; Charge blasting.

9. The method according to claim 7, characterized in that: One end of the steel column is supported on the support at the top of the first and / or second main hole, and the other end is supported on the horizontal plane of the upper step, the middle step or the lower step.

10. The method according to claim 7, characterized in that Determining the arrangement plan of the blast holes also includes setting slot holes, auxiliary holes, blast holes, peripheral holes, and bottom plate holes in the blasting excavation area.

Images