Construction method for inclined shaft section of hydraulic tunnel

Abstract

The invention relates to a construction method for an inclined shaft section of a hydraulic tunnel, which comprises the following steps of: carrying out expanding excavation on an upper bending section of the hydraulic tunnel to form a preset site; the preset installation position of the raise boring machine on the preset site is determined, the preset installation position is set in the mode that the central axis of the raise boring machine coincides with the design axis of the hydraulic tunnel, and the raise boring machine is installed on the preset installation position; the raise boring machine is debugged, and the central axis of a drill bit of the raise boring machine coincides with the extension line of the design axis; a pilot hole and a reverse pilot well are formed in the to-be-excavated inclined shaft section of the hydraulic tunnel through a raise boring machine; and blasting the to-be-excavated inclined shaft section layer by layer to form an inclined shaft section, and determining the position of a blast hole by utilizing the design axis and the design contour line of each layer of the to-be-excavated inclined shaft section before blasting of each layer of the to-be-excavated inclined shaft section. By adopting the construction method of the inclined shaft section of the hydraulic tunnel, the actual axis of the inclined shaft section can be prevented from deviating from the design axis of the inclined shaft section, and the excavation accuracy of the inclined shaft section can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of inclined shaft construction, and in particular, to a construction method for an inclined shaft section of a hydraulic tunnel. Background Art

[0002] The inclined shaft section of a hydraulic tunnel is usually located in the middle section of the hydraulic tunnel. The inclined shaft section has a certain inclination angle with the horizontal plane and is mainly used to connect the upper bend section and the lower bend section. In related technologies, the current construction method easily causes the actual axis of the inclined shaft section to deviate from the designed axis of the inclined shaft section. Summary of the invention

[0003] The purpose of the present invention is to provide a construction method for an inclined shaft section of a hydraulic tunnel. The construction method for an inclined shaft section of a hydraulic tunnel can prevent the actual axis of the inclined shaft section from deviating from the designed axis of the inclined shaft section, which is beneficial to improving the accuracy of excavation of the inclined shaft section.

[0004] In order to achieve the above object, the present disclosure provides a construction method for a hydraulic tunnel inclined shaft section, the construction method comprising the following steps: Excavate the upper bend of the hydraulic tunnel to form a preset site; Determine a preset installation position of the raise boring machine on the preset site, wherein the preset installation position is set such that the central axis of the raise boring machine coincides with the design axis of the hydraulic tunnel, and install the raise boring machine at the preset installation position; The raise boring machine is debugged so that the central axis of the drill bit of the raise boring machine coincides with the extension line of the designed axis; Use a reverse well drilling machine to open a pilot hole and a reverse well in the inclined well section to be excavated in the hydraulic tunnel; The inclined shaft section to be excavated is blasted layer by layer to form an inclined shaft section, wherein, before blasting, the position of the blast hole of each layer of the inclined shaft section to be excavated is determined by using the design axis and the design contour line of each layer of the inclined shaft section to be excavated.

[0005] Optionally, the construction method includes, when opening blast holes for the last layer of inclined well section to be excavated, making the depth of the blast holes smaller than the depth of the last layer of inclined well section to be excavated.

[0006] Optionally, the construction method includes ensuring that the difference between the blasthole depth of the last layer of inclined well section to be excavated and the depth of the last layer of inclined well section to be excavated is not less than 15 cm to 25 cm.

[0007] Optionally, the multiple layers of inclined well sections to be excavated include a last layer of inclined well sections to be excavated and each of the remaining layers of inclined well sections to be excavated, wherein the construction method includes: setting the depth of the last layer of inclined well sections to be excavated to be greater than the depth of each of the remaining layers of inclined well sections to be excavated.

[0008] Optionally, except for the last layer of the inclined well section to be excavated, the depth of each remaining layer of the inclined well section to be excavated is set to 0.8m~1.6m.

[0009] Optionally, the construction method includes: setting the depth of the last layer of inclined shaft section to be excavated to 2.5m~3.5m.

[0010] Optionally, the hydraulic tunnel includes multiple inclined shaft sections to be excavated, and the multiple inclined shaft sections to be excavated are arranged at intervals along a preset direction and are numbered 1#, 2#, 3#...N# in sequence. The construction method of the inclined shaft sections of the hydraulic tunnel includes: first excavating the odd-numbered inclined shaft sections to be excavated, and then excavating the even-numbered inclined shaft sections to be excavated, or first excavating the even-numbered inclined shaft sections to be excavated, and then excavating the odd-numbered inclined shaft sections to be excavated.

[0011] Optionally, when the excavation depth of the inclined shaft section to be excavated is less than 20m, the construction method further comprises: Arrange a ladder between the upper curved section and the inclined shaft section to be excavated after excavation; According to the determined positions of the blastholes of each layer of the inclined well section to be excavated, blastholes are opened on each layer of the inclined well section to be excavated; After charging the blasthole, blast each layer of the inclined shaft section to be excavated; Remove the slag from the inclined shaft section to be excavated after excavation; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

[0012] Optionally, when the excavation depth of the inclined well section to be excavated is greater than or equal to 20 m and the last layer of the inclined well section to be excavated is in the inclined well section to be excavated, the construction method further comprises: An electric hoist is installed on the top anchor of the upper curved section; The electric hoist is used to selectively transfer the work trolley to the inclined shaft section to be excavated after excavation. According to the determined positions of the blastholes of each layer of the inclined well section to be excavated, blastholes are opened on each layer of the inclined well section to be excavated; After charging the blasthole, blast each layer of the inclined shaft section to be excavated; After excavation, an excavator is arranged in the inclined shaft section to be excavated, and the excavator is used to remove the slag; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

[0013] Optionally, when excavating the last layer of the inclined shaft section to be excavated, the construction method further includes: According to the determined position of the blastholes of the last layer of the inclined well section to be excavated, blastholes are opened on the last layer of the inclined well section to be excavated; After charging in the blasthole, blast the last layer of the inclined shaft section to be excavated; Remove the slag from the last layer of the inclined shaft section to be excavated after excavation; Set up a rack on one side of the inclined shaft section to be excavated near the lower bend section after excavation; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

[0014] Through the above technical scheme, the construction method of the inclined shaft section of the hydraulic tunnel provided by the present invention can install and debug the raise boring machine, so that the central axis of the drill bit of the raise boring machine can coincide with the extension line of the design axis, thereby ensuring the accuracy of the drilling position. In addition, before blasting each layer of the inclined shaft section to be excavated, the position of the blasthole is determined by using the design axis and the design contour line of each layer of the inclined shaft section to be excavated, thereby ensuring the position accuracy of the blastholes of each layer of the inclined shaft section to be excavated, ensuring that each layer of the inclined shaft section to be excavated can be accurately blasted, thereby avoiding the actual axis of the inclined shaft section from deviating from the design axis of the inclined shaft section, thereby ensuring the accuracy of the overall excavation of the inclined shaft section.

[0015] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 It is a structural schematic diagram of a hydraulic tunnel provided according to an embodiment of the present disclosure; Figure 2 is a schematic structural diagram of a deviated well section provided according to an embodiment of the present disclosure; Figure 3 It is a layout relationship diagram of blastholes and designed contour lines when blasting in the inclined shaft section of a hydraulic tunnel provided according to an embodiment of the present disclosure; Figure 4 It is a flowchart of a construction method for an inclined shaft section of a hydraulic tunnel provided according to an embodiment of the present disclosure.

[0017] Description of Reference Numerals 100- hydraulic tunnel; 10- upper bend section; 101- designed axis; 102- designed contour line; 103- actual contour line; 20- inclined shaft section; 201- pilot hole; 202- reverse guide shaft; 30- lower bend section; 40- blast hole. DETAILED DESCRIPTION

[0018] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0019] In the present disclosure, unless otherwise indicated, directional words such as "upper" and "lower" are used to refer to Figure 1The terms "first", "second", etc. are used to distinguish different components and do not have order or importance. In addition, in the following description, when referring to the drawings, unless otherwise explained, the same reference numerals in different drawings represent the same or similar elements.

[0020] Reference Figure 1 As shown in , the hydraulic tunnel 100 is divided into an upper bend section 10 , an inclined shaft section 20 , and a lower bend section 30 along the water flow direction, and the inclined shaft section 20 connects the upper bend section 10 and the lower bend section 30 .

[0021] According to some embodiments of the present disclosure, Figures 1 to 4 As shown, a construction method for an inclined shaft section of a hydraulic tunnel is provided, the construction method comprising step 401, that is, excavating the upper curved section 10 of the hydraulic tunnel 100 to form a preset site; after the excavation of the preset site is completed, executing step 402, determining a preset installation position of a raise boring machine on the preset site, the preset installation position is set to: the central axis of the raise boring machine coincides with the design axis 101 of the hydraulic tunnel 100, and the raise boring machine is installed at the preset installation position, here, a total station can be used to measure and verify the preset installation position; after the raise boring machine is installed at the preset installation position, executing step 40 3. Debug the raise boring machine so that the central axis of the drill bit of the raise boring machine coincides with the extension line of the design axis 101; after the debugging of the raise boring machine is completed, execute step 404, and use the raise boring machine to open a pilot hole 201 and a reverse pilot hole 202 on the inclined well section to be excavated in the hydraulic tunnel; after the opening of the pilot hole 201 and the reverse pilot hole 202 is completed, execute step 405, and blast the inclined well section to be excavated layer by layer to form an inclined well section 20, wherein, before blasting, the design axis 101 and the design contour line 102 of each layer of the inclined well section to be excavated are used to determine the position of the blast hole 40.

[0022] Through the above technical scheme, the construction method of the inclined shaft section of the hydraulic tunnel provided by the present invention can install and debug the reverse drilling rig, which can make the central axis of the drill bit of the reverse drilling rig coincide with the extension line of the design axis, thereby ensuring the accuracy of the drilling position. In addition, by using the design axis 101 and the design contour line 102 of each layer of the inclined shaft section to be excavated before blasting, the position of the blasthole 40 is determined, thereby ensuring the position accuracy of the blasthole 40 of each layer of the inclined shaft section to be excavated, ensuring that each layer of the inclined shaft section to be excavated can be accurately blasted, thereby avoiding the actual axis of the inclined shaft section 20 from deviating from the design axis 101 of the inclined shaft section 20, thereby ensuring the accuracy of the overall excavation of the inclined shaft section 20.

[0023] It should be noted that, refer to Figure 3As shown in , the design axis 101 refers to the theoretical axis of the inclined shaft section 20, and the design contour line 102 is the tunnel clearance section and the tunnel support or lining dimension line determined based on the design axis 101. The contour line generated by excavation, that is, the actual contour line 103, has a large error, and it is difficult to accurately determine the position of the blasthole 40. Determining the position of the blasthole 40 based on the design contour line 102 is conducive to quickly and accurately determining the position of the blasthole 40, thereby helping to improve the blasting accuracy and blasting efficiency. Specifically, according to the coordinates of the theoretical axis, during actual excavation, the design axis position and design contour line 102 of the inclined shaft section are obtained based on the existing control points outside the tunnel and the control network in the excavated tunnel section. Among them, obtaining the design axis position and design contour line 102 of the inclined shaft section based on the existing control points outside the tunnel and the control network in the excavated tunnel section belongs to the existing method, and this disclosure will not be described in detail.

[0024] In the present disclosure, concrete pouring can be used to form a raise boring rig foundation at a preset installation position to ensure the reliability of the raise boring rig installation, wherein the pouring method of the raise boring rig foundation is: clean the bedrock surface; after the rock surface is cleaned, C20 concrete is used for the first phase of pouring to form the raise boring rig foundation. This process requires reserving a pit for the anchor bolts of the raise boring rig. After the raise boring rig is placed in place and initially calibrated, the second phase of concrete is backfilled to ensure that the raise boring rig is firmly connected to the raise boring rig foundation. The size of the raise boring rig foundation is 5.85m×3.6m×1.0m (length×width×height).

[0025] In order to facilitate the installation of the raise boring machine in the tunnel, a transport track is installed on the ground at the unloading location in the tunnel before installation. The track gauge can be set to 55cm~65cm, the track uses 24kg / m light rail, the sleepers use 10cm×10cm square wood, and the spacing can be set to 50cm / piece, so that the raise boring machine can be quickly put into place using the track and sleepers for installation.

[0026] When installing the raise boring rig at the preset installation position, a 20t flatbed truck can be used to transport the raise boring rig to the unloading location in the tunnel, and the raise boring rig can be unloaded and hoisted by pre-burying sky anchors on the top of the tunnel and hanging chain cranes. At the same time, it can be assisted by hydraulic jacks and other tools to achieve the installation of the raise boring rig and improve the convenience of installation.

[0027] After the raise boring machine is installed in the preset installation position, the raise boring machine is debugged. The debugging method is as follows: lift the raise boring machine with the rear support rod to make the front and rear directions of the raise boring machine perpendicular to the ground; use the plumb line measurement method, that is, hang a plumb line on each side of the raise boring machine, and place a pad under the bottom plate of the raise boring machine to make the left and right directions of the raise boring machine perpendicular to the ground; then, use the total station to measure the drilling rig angle and the center point of the borehole, where the drilling rig angle coincides with the design axis 101, and the intersection of the design axis 101 and the excavation surface is the center point of the borehole. Through the above method, it is ensured that the central axis of the drill bit of the raise boring machine coincides with the extension line of the design axis 101.

[0028] In order to prevent the blasting debris from causing the well to be blocked, the steps of opening the pilot hole 201 and the reverse well 202 include: Figure 1 As shown in , a pilot hole is drilled from top to bottom (i.e., from the side of the inclined well section to be excavated close to the upper bend section toward the side of the inclined well section to be excavated close to the lower bend section) by using a reverse drilling rig, wherein the aperture of the pilot hole 201 after drilling can be set to Φ290mm~Φ300mm, and illustratively, the aperture of the pilot hole 201 can be set to Φ290mm, Φ295mm or Φ300mm; after drilling the pilot hole 201, the pilot hole drill bit is removed, and the expansion drill bit is installed, The reverse well 202 is drilled from bottom to top by the reverse well drilling machine, that is, the reverse well 202 is drilled from the side of the inclined well section to be excavated close to the lower bend section 30 toward the side of the inclined well section to be excavated close to the upper bend section 10 by the reverse well drilling machine, wherein the reverse well 202 is a slag well, and the aperture of the reverse well 202 can be set to Φ2.2m~Φ2.6m. For example, the aperture of the reverse well can be set to Φ2.2m, Φ2.4m or Φ2.6m. In this way, when the inclined well section to be excavated is blasted layer by layer, the slag can slide to the lower part of the inclined well section through the reverse well 202 and be discharged, which is conducive to simplifying the construction process and improving the construction efficiency.

[0029] Among them, when reverse pulling and drilling the reverse well 202, the drilling speed of the reverse well drilling rig can be set to 8cm / h~12cm / h. For example, the drilling speed of the reverse well drilling rig can be set to 8cm / h, 10cm / h or 12cm / h. By controlling the drilling speed, the drilling accuracy of the pilot hole can be improved and the drilling deviation can be reduced. That is to say, the deviation of the actual axis of the inclined well section can be reduced, thereby ensuring the smooth progress of the construction operation and improving safety.

[0030] In the present disclosure, after the pilot hole is penetrated and before the expansion drill bit is installed, it is necessary to determine that there are no metal support structures such as anchor rods at the underground through-hole position of the hydraulic tunnel 100. If there are anchor rods, they need to be removed before the expansion operation is carried out. After replacing the expansion drill bit, in order to make the expansion drill bit smoothly carry out the expansion operation, when starting the reverse pull work, the drilling parameters are set to small torque and small drilling pressure for initial expansion. After the expansion drill bit is completely entered into the hole, expansion drilling is started at a drilling speed of 10 cm / h.

[0031] In order to avoid deviation of the actual axis of the inclined well section, when opening the pilot hole 201 and the return well 202, the drilling pressure of the drill bit can be reduced for soft formations and transition formations, and the drilling pressure can be increased for hard rock and stable formations to facilitate control of the drilling direction.

[0032] In order to avoid the deviation of the actual axis due to over-excavation, when executing step 401, that is, when the upper bend section 10 of the hydraulic tunnel 100 is expanded to form a preset site, the principle of "short advance, weak blasting, and multiple cycles" is adopted. The excavation depth of each cycle can be controlled within 1.0m~1.5m, which can better control the over-excavation project volume within the design requirements, and is conducive to accelerating the construction progress and facilitating construction.

[0033] According to some embodiments of the present disclosure, the construction method may include, when opening a blast hole 40 for the last layer of the inclined well section to be excavated, making the depth of the blast hole 40 smaller than the depth of the last layer of the inclined well section to be excavated. By making the depth of the blast hole 40 smaller than the depth of the last layer of the inclined well section to be excavated, it is prevented that the explosives fall from the bottom of the last layer of the inclined well section to be excavated when the last layer of the inclined well section to be excavated is filled with explosives for blasting, and it is ensured that the explosives are stably filled in the blast hole 40.

[0034] According to some embodiments of the present disclosure, the construction method may include making the depth of the blasthole 40 of the last layer of the inclined well section to be excavated differ from the depth of the last layer of the inclined well section to be excavated by no less than 15cm~25cm. In this way, the blasthole 40 on the last layer of the inclined well section to be excavated is a blind hole, which prevents the explosive from falling from the bottom of the blasthole 40 after filling. For example, the depth of the blasthole 40 of the last layer of the inclined well section to be excavated differs from the depth of the last layer of the inclined well section to be excavated by 15cm, 20cm or 25cm. The present disclosure does not impose specific restrictions on this, as long as it can prevent the explosive from falling from the bottom of the blasthole 40 after filling, and can make the last layer of the inclined well section to be excavated be able to be penetrated at one time after blasting, which is conducive to simplifying the construction process and improving construction efficiency.

[0035] According to some embodiments of the present disclosure, the multiple layers of inclined shaft sections to be excavated include the last layer of inclined shaft sections to be excavated and each of the remaining layers of inclined shaft sections to be excavated, wherein the construction method includes: setting the depth of the last layer of inclined shaft sections to be excavated to be greater than the depth of each of the remaining layers of inclined shaft sections to be excavated. Since the last layer of inclined shaft sections to be excavated is close to the lower bend section, setting the depth of the last layer of inclined shaft sections to be excavated to be greater than the depth of each of the remaining layers of inclined shaft sections to be excavated is conducive to better control of the one-time blasting depth and the direction of excavation expansion, avoiding over-excavation, that is, avoiding the actual blasting depth exceeding the blasting depth required by the design, which causes the axis of the inclined shaft section to be offset, and is conducive to improving the accuracy of excavation of the inclined shaft section of the hydraulic tunnel.

[0036] According to some embodiments of the present disclosure, Figure 1 and Figure 2 As shown in , except for the last layer of inclined well sections to be excavated, the depth of each remaining layer of inclined well sections to be excavated is set to 0.8m~1.6m. Exemplarily, the depth of each remaining layer of inclined well sections to be excavated can be set to 0.8m, 1.0m, 1.5m or 1.6m, and the present disclosure does not impose specific restrictions on this. By controlling the depth of each remaining layer of inclined well sections to be excavated, it is beneficial to blast and expand each remaining layer of inclined well sections to be excavated layer by layer, and it can avoid safety accidents such as landslides and water gushing caused by the excessive depth of a layer of inclined well sections to be excavated. In addition, by reasonably controlling the depth of each layer of inclined well sections to be excavated, resources and manpower can be better deployed to avoid waste of resources and construction delays caused by the excessive depth of each layer of inclined well sections to be excavated, thereby helping to improve construction efficiency and quality.

[0037] According to some embodiments of the present disclosure, Figure 1 and Figure 2 As shown in , the construction method includes: setting the depth of the last layer of inclined shaft section to be excavated to 2.5m~3.5m. Exemplarily, the depth of the last layer of inclined shaft section to be excavated can be set to 2.5m, 3m or 3.5m, and the present disclosure does not make specific restrictions on this. By controlling the depth of the last layer of inclined shaft section to be excavated, the last layer of inclined shaft section to be excavated can be expanded and penetrated at one time, that is, blasted at one time, and over-excavation can be avoided, which is conducive to controlling the accuracy of excavation.

[0038] According to some embodiments of the present disclosure, Figure 1As shown in , the hydraulic tunnel 100 includes multiple inclined shaft sections to be excavated, and the multiple inclined shaft sections to be excavated are arranged at intervals along a preset direction and are numbered 1#, 2#, 3#...N# in sequence. The construction method of the inclined shaft sections of the hydraulic tunnel includes: first excavating the inclined shaft sections to be excavated with odd numbers, and then excavating the inclined shaft sections to be excavated with even numbers, or first excavating the inclined shaft sections to be excavated with even numbers, and then excavating the inclined shaft sections to be excavated with odd numbers. Through the above arrangement, when multiple inclined shaft sections to be excavated are constructed synchronously, it is possible to avoid mutual interference between adjacent inclined shaft sections to be excavated during the excavation process, and avoid the impact of blasting vibration on adjacent inclined shaft sections, which is beneficial to improving the safety during the construction process and the construction quality of the hydraulic tunnel.

[0039] In the present disclosure, the spacing between adjacent inclined shaft sections to be excavated can be determined based on the surrounding rock conditions, cavern size, blasting parameters, and construction technology, and the present disclosure does not make specific limitations on this.

[0040] The following is an explanation of the construction method based on the different processes of blasting in the inclined shaft section to be excavated: When the excavation depth of the inclined shaft section to be excavated is less than 20m, the construction method also includes: A ladder is arranged between the upper curved section 10 and the inclined shaft section to be excavated after excavation, so that personnel can enter the working surface in the inclined shaft section hole through the ladder to perform related operations. In addition, the ladder is relatively light and convenient to selectively arrange the ladder at a suitable position between the upper curved section 10 and the inclined shaft section to be excavated after excavation, which is conducive to simplifying the construction process and improving the convenience of construction; Afterwards, according to the determined position of the blastholes 40 of each layer of the inclined well section to be excavated, the blastholes 40 are opened on each layer of the inclined well section to be excavated. Specifically, according to the design axis 101 and the design contour line 102 of each layer of the inclined well section to be excavated, the positions of the blastholes 40 are determined and marked, and the blastholes 40 are opened to ensure the accuracy of the blastholes 40. After charging in the blasthole 40, blasting is performed on each layer of the inclined shaft section to be excavated. This step can be performed by a winch lifting system, that is, the explosives and detonators are hoisted to the working face by the winch lifting system, and the charging, networking and blasting operations are completed; Remove the slag from the inclined shaft section to be excavated after excavation; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

[0041] When the excavation depth of the inclined shaft section to be excavated is greater than or equal to 20m and the inclined shaft section to be excavated is the last layer of the inclined shaft section to be excavated, the construction method further includes: Reference Figure 1 As shown in , an electric hoist is arranged on the top sky anchor of the upper curved section 10; The electric hoist is used to selectively transfer the work trolley to the inclined shaft section to be dug after excavation. That is, when the work trolley is needed, the electric hoist is used to transfer the work trolley to the inclined shaft section to be dug after excavation. When the work trolley is used, the electric hoist is used to move the work trolley out of the inclined shaft section to be dug after excavation, thereby improving the convenience of construction; According to the determined position of the blastholes 40 of each layer of the inclined well section to be excavated, the blastholes 40 are opened on each layer of the inclined well section to be excavated. Specifically, according to the design axis 101 and the design contour line 102 of each layer of the inclined well section to be excavated, the positions of the blastholes 40 are determined and marked, and the blastholes 40 are opened to ensure the accuracy of the blastholes 40; After charging in the blasthole 40, blasting is performed on each layer of the inclined shaft section to be excavated; After excavation, an excavator is set up in the inclined shaft section to be excavated, and the excavator is used to remove the slag. The use of the excavator is conducive to improving the efficiency of removing the slag and speeding up the construction progress; For the anchor spraying support of the inclined shaft section to be excavated after excavation, here, a concrete dry spraying machine is used to spray C20 concrete on the inclined shaft section to be excavated after excavation using the dry spraying process.

[0042] When excavating the last layer of the inclined shaft section to be excavated, the construction method also includes: According to the determined position of the blasthole 40 of the last layer of the inclined well section to be excavated, the blasthole 40 is opened on the last layer of the inclined well section to be excavated. Here, the depth of the blasthole 40 is less than the depth of the last layer of the inclined well section to be excavated, so as to ensure that the explosives will not fall out after filling; After charging in the blasthole 40, the last layer of the inclined shaft section to be excavated is blasted; Remove the slag from the last layer of the inclined shaft section to be excavated after excavation; A bent frame is set up on one side of the inclined shaft section to be excavated after excavation, close to the lower bend section 30, and the bent frame is set up to facilitate the subsequent operation of the last layer of the inclined shaft section to be excavated through the bent frame; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

[0043] Among them, anchor spraying support can adopt the construction process of anchoring first and then spraying. For weak rock masses, fault fracture zones, and areas with developed joints and fissures, the first layer of concrete can be sprayed for sealing and protection, followed by anchor construction, and finally concrete spraying to the designed thickness. When spraying concrete, the thickness of the sprayed concrete is set to 5cm~8cm for one spraying, and the thickness of the arch sprayed concrete is set to 4~6cm; when layered spraying is required, the thickness of one spraying is sufficient to prevent the sprayed layer from falling and sliding. The next layer of sprayed concrete should be carried out after the previous sprayed concrete has finally set. If it is sprayed again one hour after the final setting, the surface latex and floating dust should be washed clean with Feng Shui first.

[0044] In order to ensure the support performance, when the spraying operation is closely followed by the excavation working face, the interval time from the final setting of the concrete to the next cycle of blasting should not be less than 4 hours, and the average thickness of the sprayed concrete shall not be less than the designed thickness, and the thinnest part shall not be less than 75% of the designed thickness; In addition, the amount of rebound should be minimized during spraying. Under normal circumstances, the rebound rate of the side wall should not be greater than 10%, and that of the top arch should not be greater than 20%. The rebound material must not be reused. If it is found that the sprayed layer has fallen off or a large amount of rebound material is "held" by the steel mesh, it must be removed in time and must not be wrapped in the sprayed layer. The over-excavated part outside the structural line formed due to geological reasons and the cavity between the bedrock surface of the steel arch frame must all be backfilled and compacted with sprayed concrete.

[0045] In order to improve the accuracy of the actual axis of the inclined shaft section 20, after the excavation of each layer of the inclined shaft section to be excavated is completed, laser alignment and TAPS-non-contact automatic polar coordinate measurement system, or photoelectric rangefinders that do not require reflecting prisms and other equipment can be used to carry out layout corrections based on the cavern axis, point position, elevation and excavation section, so that the error between the excavation contour line and the design contour line 102 is no more than 50mm.

[0046] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0048] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A construction method for an inclined shaft section of a hydraulic tunnel, characterized in that: The construction method comprises the following steps: Excavate the upper bend of the hydraulic tunnel to form a preset site; Determine a preset installation position of the raise boring machine on the preset site, wherein the preset installation position is set such that the central axis of the raise boring machine coincides with the design axis of the hydraulic tunnel, and install the raise boring machine at the preset installation position; The raise boring machine is debugged so that the central axis of the drill bit of the raise boring machine coincides with the extension line of the designed axis; Use a reverse well drilling machine to open a pilot hole and a reverse well in the inclined well section to be excavated in the hydraulic tunnel; The inclined shaft section to be excavated is blasted layer by layer to form an inclined shaft section, wherein, before blasting, the position of the blast hole of each layer of the inclined shaft section to be excavated is determined by using the design axis and the design contour line of each layer of the inclined shaft section to be excavated.

2. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1, characterized in that: The construction method includes, when opening blast holes in the last layer of inclined well section to be excavated, making the depth of the blast holes smaller than the depth of the last layer of inclined well section to be excavated.

3. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 2 is characterized in that: The construction method includes ensuring that the difference between the depth of the blasthole of the last layer of the inclined well section to be excavated and the depth of the last layer of the inclined well section to be excavated is not less than 15 cm to 25 cm.

4. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1, characterized in that: The multiple layers of inclined well sections to be excavated include the last layer of inclined well sections to be excavated and each of the remaining layers of inclined well sections to be excavated, wherein the construction method includes: setting the depth of the last layer of inclined well sections to be excavated to be greater than the depth of each of the remaining layers of inclined well sections to be excavated.

5. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1 or 4, characterized in that: Except for the last layer of the inclined shaft section to be excavated, the depth of each of the remaining layers of the inclined shaft section to be excavated is set to 0.8m~1.6m.

6. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 4, characterized in that: The construction method comprises: setting the depth of the last layer of inclined shaft section to be excavated to 2.5m-3.5m.

7. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1, characterized in that: The hydraulic tunnel comprises a plurality of inclined shaft sections to be excavated, wherein the plurality of inclined shaft sections to be excavated are arranged at intervals along a preset direction and are numbered 1#, 2#, 3#...N# in sequence. The construction method of the inclined shaft sections of the hydraulic tunnel comprises: first excavating the odd-numbered inclined shaft sections to be excavated, and then excavating the even-numbered inclined shaft sections to be excavated, or first excavating the even-numbered inclined shaft sections to be excavated, and then excavating the odd-numbered inclined shaft sections to be excavated.

8. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1, characterized in that: When the excavation depth of the inclined shaft section to be excavated is less than 20m, the construction method further comprises: Arrange a ladder between the upper curved section and the inclined shaft section to be excavated after excavation; According to the determined positions of the blastholes of each layer of the inclined well section to be excavated, blastholes are opened on each layer of the inclined well section to be excavated; After charging the blasthole, blast each layer of the inclined shaft section to be excavated; Remove the slag from the inclined shaft section to be excavated after excavation; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

9. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1, characterized in that: When the excavation depth of the inclined well section to be excavated is greater than or equal to 20m and the inclined well section to be excavated is the last layer of the inclined well section to be excavated, the construction method further comprises: An electric hoist is installed on the top anchor of the upper curved section; The electric hoist is used to selectively transfer the work trolley to the inclined shaft section to be excavated after excavation. According to the determined positions of the blastholes of each layer of the inclined well section to be excavated, blastholes are opened on each layer of the inclined well section to be excavated; After charging the blasthole, blast each layer of the inclined shaft section to be excavated; After excavation, an excavator is arranged in the inclined shaft section to be excavated, and the excavator is used to remove the slag; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

10. The construction method of the inclined shaft section of a hydraulic tunnel according to claim 1, characterized in that: When excavating the last layer of the inclined shaft section to be excavated, the construction method further includes: According to the determined position of the blastholes of the last layer of the inclined well section to be excavated, blastholes are opened on the last layer of the inclined well section to be excavated; After charging in the blasthole, blast the last layer of the inclined shaft section to be excavated; Remove the slag from the last layer of the inclined shaft section to be excavated after excavation; Set up a rack on one side of the inclined shaft section to be excavated near the lower bend section after excavation; Anchor and spray support is provided for the inclined well section to be excavated after excavation.

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