Rock storage cavern excavation construction method

Abstract

The invention belongs to the technical field of rock underground engineering construction, and discloses a rock storage cavern excavation construction method. The construction method aims at solving the technical problems that when a rock chamber is excavated through an existing blasting method, surrounding rock disturbance is large, sealing performance is difficult to guarantee, and deep space utilization is limited. According to the technical scheme, the method comprises the steps of 1, lithology analysis and chamber design; secondly, an outdoor transportation device is arranged; step 3, excavating a tunnel into the tunnel; fourthly, the first layer of the chamber is excavated, the distributed pilot holes are excavated firstly, then a first layer space is formed through expanding excavation, the side walls and the top of the chamber are constructed through a non-blasting mechanical cutting method so as to control surrounding rock damage, and a lifting device is arranged in the first layer of the chamber; and fifthly, the chamber space is excavated in a layered mode, a stone cutting machine is arranged on the first layer, rock mass is cut in a layered mode from top to bottom, and cut stone is conveyed out through a lifting device. And sixthly, the multi-chamber space is excavated. The method is suitable for rapid non-disturbance excavation construction of rock underground reservoir projects such as compressed air energy storage chambers and the like which have high requirements on the sealing performance of surrounding rocks.

Description

Technical Field

[0001] This invention belongs to the field of underground rock engineering construction technology, specifically relating to a construction method for excavating rock storage chambers, which is particularly suitable for the undisturbed and rapid excavation of compressed air energy storage chambers. Background Technology

[0002] Rock storage chambers, as underground storage spaces, can be used for large-scale storage of various media, including liquids, gases, and particulate materials. Among them, compressed air energy storage technology has broad application prospects. Its working principle is as follows: air is compressed and stored in underground chambers using off-peak electricity, and released during peak electricity demand to drive turbines to generate electricity, thus achieving the spatial and temporal transfer of electrical energy. This technology enables unstable new energy sources such as wind power and photovoltaic power to achieve stable grid connection. Unlike traditional gas storage methods that rely on salt caverns, artificial rock chambers can be constructed in medium-hard to hard rock masses such as limestone, granite, and sandstone, overcoming the geographical limitations of salt rock distribution. They offer advantages such as flexible site selection, large energy storage capacity, long service life, and zero carbon emissions during operation. Currently, the cycle efficiency of compressed air energy storage systems can reach over 70%, and related technologies are rapidly moving towards large-scale industrialization.

[0003] However, existing rock chamber excavation technology still has the following limitations in practical engineering applications: First, the construction cost is high. The excavation and support processes for large-section rock chambers under hard rock conditions are complex, requiring significant equipment investment and a long construction period, thus the overall economic efficiency needs further improvement. Second, controlling surrounding rock damage is difficult. High-pressure gas storage places extremely stringent requirements on the sealing performance of the chamber. When using traditional drill-and-blast methods, the blasting vibration significantly disturbs the surrounding rock, easily leading to loosening of the surrounding rock mass and micro-crack damage, increasing the difficulty and cost of subsequent sealing treatment. Studies have shown that once the sealing lining cracks, a crack rate exceeding 2% will result in a significant decrease in gas storage efficiency. Third, the utilization of deep space is limited. Currently, most artificially excavated rock chambers that have been built or are under construction use blasting methods to form large-diameter horizontal tunnels, and there is a lack of mature construction methods for the development and utilization of deep underground spaces. In summary, there is an urgent need for a tunnel excavation construction method that is highly efficient, causes minimal disturbance to the surrounding rock, and can adapt to deep rock conditions. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide a construction method for excavating rock storage chambers. This method enables rapid and undisturbed excavation of deep hard rock chambers, effectively controls damage to the surrounding rock, and ensures the long-term sealing performance of the chamber. To achieve the above objective, this invention adopts the following technical solution: a construction method for excavating rock storage chambers, comprising the following steps: Step 1, lithological analysis and chamber design; Step 2, setting up external transportation devices for the chamber; Step 3, excavating the entrance tunnel; Step 4, excavating the first layer of the chamber; Step 5, excavating the chamber space in layers; Step 6, excavating the multi-chamber space.

[0005] Furthermore, the lithological analysis and chamber design described in step one include: drilling core samples from the target rock strata, conducting physical and mechanical property tests and chemical composition analysis on the samples, and classifying and evaluating the stability of the surrounding rock in the proposed excavation area based on the test results; and determining the burial depth, geometric dimensions, axial orientation, and excavation construction plan of the chamber based on the test data and stability evaluation results.

[0006] Furthermore, step two, setting up the external transportation device for the tunnel, includes: constructing an external transportation channel and related facilities based on the topography and construction organization conditions at the tunnel entrance. The external transportation device includes at least one of road construction, erection of a well tower, or elevator frame. When a well tower or elevator frame is used, it is equipped with a lifting mechanism for the vertical transportation of construction materials, machinery, and excavated stone.

[0007] Further, step three, excavating the entrance tunnel, includes: excavating the entrance tunnel into the rock mass at the location corresponding to the external transport device. The excavation direction and slope of the entrance tunnel are not limited and can be determined according to the burial depth of the chamber and geological conditions. The entrance tunnel may be equipped with multiple exits to reserve escape routes. The entrance tunnel includes a main tunnel and branch tunnels, with N branch tunnels (where N≥1). The excavation method of the entrance tunnel is selected from one or more of the following: blasting, drilling, cutting, and shield tunneling. Among them, the cutting method includes wire saw cutting, chain saw cutting, chain arm saw cutting, and circular saw cutting. A lifting device may be installed inside the entrance tunnel. The excavated rock is transported out of the chamber through the lifting device inside the entrance tunnel and the external transport device.

[0008] Further, step four, excavating the first level of the chamber, includes: after completing the excavation of the entrance tunnel and reaching the designed chamber boundary, excavating a pilot tunnel, which is arranged in a distributed structure; then, based on the pilot tunnel, expanding the excavation to the periphery and upwards to form the first level space of the chamber. The excavation of the central part of the first level of the chamber employs one or more of the following methods: blasting, drilling, or cutting; the excavation of the chamber sidewalls and the top area of ​​the chamber employs the cutting method to avoid damage to the surrounding rock caused by blasting vibrations. After the excavation of the first level of the chamber is completed, a lifting device is installed within this level, including a gantry crane or a hoist. The gantry crane beams and components can be designed in multiple sections to allow for segmented entry and on-site assembly.

[0009] Furthermore, step five, the layered excavation of the chamber space, includes: arranging stone cutting machinery in the first layer of the excavated chamber, wherein the stone cutting machinery is selected from one or more of a circular saw, chain arm saw, wire saw, and wire saw; using the stone cutting machinery to cut and separate the rock mass in the chamber space into layers; transporting the cut stone to the first layer of the chamber through the lifting device, and then transporting it out of the chamber through the entrance tunnel and the external transportation device; repeating the above cutting and transportation operations, excavating layer by layer from top to bottom until the chamber space reaches the designed size.

[0010] Furthermore, when the entrance tunnel is connected to multiple chamber spaces as described in step six, the excavation operations described in steps four and five can be performed simultaneously or sequentially on each chamber space at different locations within the entrance tunnel.

[0011] Compared with existing technologies, this invention has the following advantages: First, it offers high excavation efficiency and fast construction speed. The construction method combining layered cutting and mechanized transportation ensures close connection between processes, enabling rapid formation of the chamber space. Second, it minimizes disturbance to the surrounding rock and controls damage effectively. Non-explosive mechanical cutting is used in key areas of the chamber's sidewalls and top, effectively avoiding loosening and micro-cracks caused by blasting vibrations to the reserved surrounding rock, thus ensuring the overall stability and sealing performance of the chamber. Third, it facilitates crack detection and repair. The smooth surface of the rock wall formed by mechanical cutting makes natural joints and cracks clearly visible, facilitating timely observation, grouting, and targeted repairs during construction. Fourth, it produces high-quality chambers. The chambers excavated using this invention have regular cross-sections and low damage to the surrounding rock, meeting the technical standards for low permeability and high stability of the surrounding rock required for long-term pressurized operation of compressed air and high-level liquid storage chambers.

[0012] Figure 1 This is the overall layout diagram of the present invention.

[0013] Figure 2 This is a planar cut view of the chamber of the present invention.

[0014] The present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the following embodiments are only for explaining the present invention and do not limit the scope of protection of the present invention. Figure 1 As shown, the specific construction method for the excavation of this rock storage chamber includes the following steps: Step 1, lithological analysis and chamber design; Step 2, setting up an external transportation device 10; Step 3, excavating the entrance tunnel; Step 4, excavating the first floor 32 of the chamber; Step 5, excavating the chamber space 30; Step 6, excavating the multi-chamber space.

[0015] Step 1: Lithological Analysis and Chamber Design. Before construction, core samples of the target rock strata are obtained through geological drilling. These samples undergo rock mechanical property testing, mineral composition analysis, and physicochemical performance testing. Based on the test results, the stability of the surrounding rock in the proposed excavation area is graded and evaluated to determine the integrity of the rock mass, the development of fractures, and the state of in-situ stress. Based on the test data and evaluation results, the burial depth, span, height, and axial orientation of the chamber space 30 are determined, and suitable excavation machinery and excavation technology are selected. In this specific embodiment, the target rock strata are determined to be relatively intact granite, with a surrounding rock grade of II, making it suitable for large-section chamber excavation using the method of this invention.

[0016] Step Two: Construct an external transportation device. Based on the excavation construction organization design and site topography, an external transportation device is constructed at the tunnel entrance. This external transportation device includes a transportation road and a structure such as a shaft tower 11 or an elevator frame. In this embodiment, the external transportation device is a shaft tower 11, which is equipped with a lifting mechanism 12 for lifting the excavated stone to the surface for disposal during subsequent construction, and for transporting construction machinery and support materials into the tunnel.

[0017] Step 3: Excavation of the entrance tunnel. After setting up the external transportation device, the entrance tunnel is excavated into the rock mass from the entrance position. The excavation direction and slope of the entrance tunnel can be adjusted according to the burial depth of the chamber and geological conditions. The entrance tunnel includes a main tunnel 20 and branch tunnels 21. According to the layout design of the chamber group, N branch tunnels 21 can be set (where N≥1). In this embodiment, the main tunnel 20 is vertical and the branch tunnels 21 are horizontal. The rock material generated during the excavation of the entrance tunnel is discharged from the chamber through the lifting mechanism 12. The excavation method of the entrance tunnel can be one or more combinations of shield tunneling, drilling and blasting, or cutting methods to ensure the stability of the surrounding rock of the tunnel.

[0018] Step Four: Excavation of the First Floor of the Chamber. After completing the excavation of the entrance tunnel and reaching the design chamber boundary, excavation of the first floor of the chamber begins. To improve excavation efficiency, pilot tunnels 31 are excavated first. These pilot tunnels 31 are arranged in a distributed structure at the bottom or waist of the planned first floor of the chamber 32, providing initial free surfaces and working space for subsequent large-scale cutting of the first floor 32. The excavation of the pilot tunnels 31 can be carried out using blasting, drilling, or mechanical cutting methods, the specific method determined based on rock hardness and construction efficiency.

[0019] After the pilot tunnel 31 is excavated, it is used as a foundation to expand outwards and upwards, forming the first level 32 of the chamber. In this step, non-explosive mechanical cutting methods are strictly adopted for the sidewalls and dome of the first level 32 of the chamber. Specifically, wire saws, chainsaws, or mining circular saws are used for contour cutting to minimize the loosening and micro-crack damage to the reserved surrounding rock caused by blasting vibrations, ensuring the airtightness of the chamber as a storage space in the later stage. The rock mass in the central part of the first level 32 of the chamber can be broken by combining blasting or mechanical splitting methods to improve efficiency. After the excavation working face of the first level 32 of the chamber is formed, a lifting device 33 is erected on this level. The lifting device 33 includes a gantry crane or elevator for vertical transportation connecting the first level 32 of the chamber to the bottom working face. If the excessively long gantry crane beam cannot enter the first floor 32 of the chamber due to the limitation of the entrance tunnel, the gantry crane beam and its components can be designed as multi-segmented to allow for segmented entry and on-site assembly.

[0020] Step 5: Excavate the chamber space 30. After the first floor 32 of the chamber is constructed, stone cutting machinery 34 is arranged on the plane of the first floor 32. The stone cutting machinery 34 specifically includes a mining circular saw, a chainsaw, or a wire saw. In this embodiment, the rock stratum is granite with high hardness, and the stone cutting machinery 34 uses a combination of a mining circular saw and a wire saw. The saw blade of the circular saw should be able to pass smoothly through the entrance tunnel.

[0021] Furthermore, according to Figure 2 As shown, a mining circular saw is used to cut downwards along horizontal and vertical lines on the plane within the chamber space 30, ensuring a consistent cutting depth. The width of the blocks is smaller than the cross-sectional width of the tunnel, facilitating the smooth transport of the separated stones 35 out of the chamber.

[0022] Furthermore, a wire saw is used to horizontally cut the chamber space 30 layer by layer using the cut kerf. This separates the rock mass from the parent rock, forming sized stones 35. The separated stones 35 are then hoisted out of the first layer 32 of the chamber by the lifting device 33, and then transported to the surface through the branch tunnel 21, the main tunnel 20, and the shaft tower 11. The above cutting-transportation steps are repeated, and the chamber is excavated layer by layer from top to bottom until the designed chamber floor elevation is reached, completing the excavation and shaping of the entire chamber space 30.

[0023] Step Six: Multi-chamber Implementation Plan. Further, if the design includes multiple parallel or series chamber spaces 30, the already excavated main tunnel 20 and branch tunnel 21 can be used as construction channels to enter different chamber excavation positions and repeat steps four to five above, thereby achieving continuous, efficient, and undisturbed construction of the chamber group.

[0024] This invention, through the combination of the above steps, achieves mechanical static cutting and excavation of hard rock chambers, effectively controlling damage to the surrounding rock. Not only is the excavation cross-section regular and well-formed, but it also facilitates direct observation of the development of natural joints and fissures in the chamber rock wall during construction, enabling timely targeted grouting and fissure repair. This meets the stringent technical requirements of low permeability and high stability of the surrounding rock for long-term pressurized operation of the chamber.

Claims

1. A construction method for excavating a rock storage chamber, characterized in that, Includes the following steps: Step 1, Lithological Analysis and Chamber Design: Core samples of the target rock strata are drilled for physical and mechanical property testing and surrounding rock stability evaluation. Based on the test data and evaluation results, the chamber design parameters are determined. Step 2, Setting up External Transportation Devices: External transportation channels and lifting mechanisms are constructed based on the external conditions of the chamber entrance. Step 3, Excavate the entrance tunnel: Excavate the entrance tunnel at the location corresponding to the external transportation device of the tunnel. The entrance tunnel includes a main tunnel and branch tunnels, and N branch tunnels are provided (where N≥1). A hoisting device can be installed inside the entrance tunnel. Step 4, Excavate the first layer of the chamber: After the end of the entrance tunnel reaches the design chamber boundary, first excavate distributed pilot tunnels, and then expand the excavation based on the pilot tunnels to form the first layer of the chamber. A hoisting device is installed in the first layer. Step 5, Excavate the chamber space in layers: Arrange stone cutting machinery in the first layer of the chamber to cut the rock mass in layers from top to bottom. The cut and separated stone is transported out of the chamber through the hoisting device and the external transportation device until the excavation of the chamber space is completed. Step 6, Excavate multiple chamber spaces: When the entrance tunnel connects to multiple chamber spaces, the excavation operations of Steps 4 to 5 are repeated simultaneously or sequentially for each chamber space.

2. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The outdoor transportation device in step two includes at least one of road construction, erection of a well tower or elevator frame; the well tower or elevator frame is equipped with a lifting mechanism for transportation.

3. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The excavation direction and slope of the tunnel in step three are determined based on the burial depth of the chamber and geological conditions. The excavation method is selected from one or more combinations of blasting, drilling, cutting, and shield tunneling.

4. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The entrance tunnel described in step three can have multiple exits.

5. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The cutting method includes at least one of wire saw cutting, wire saw cutting, chain arm saw cutting, and circular saw cutting.

6. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The pilot tunnels described in step four are arranged in a distributed structure, and their excavation methods are selected from blasting, drilling, or cutting.

7. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: In step four, when expanding the excavation to form the first-level space of the chamber, a non-explosive cutting method is used for the sidewalls and dome of the chamber to control damage to the surrounding rock; the excavation of the central part of the first-level chamber is carried out by one or more of the following methods: blasting, drilling, or cutting.

8. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The lifting device mentioned in step four includes a gantry crane or a hoist, used for transporting goods between the first floor of the chamber and the bottom working surface.

9. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The gantry crane beams and components mentioned in step four can be designed in multiple sections to allow for segmented entry and on-site assembly.

10. The construction method for excavating a rock storage chamber according to claim 1, characterized in that: The stone cutting machinery mentioned in step five is selected from one or more of the following: mining circular saw, chain arm saw, wire saw, and wire saw.

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