CN111206950A - Rock pillar supporting structure in ultra-flat chamber and construction method - Google Patents
Rock pillar supporting structure in ultra-flat chamber and construction method Download PDFInfo
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- CN111206950A CN111206950A CN202010110393.7A CN202010110393A CN111206950A CN 111206950 A CN111206950 A CN 111206950A CN 202010110393 A CN202010110393 A CN 202010110393A CN 111206950 A CN111206950 A CN 111206950A
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
- E21D21/0026—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection characterised by constructional features of the bolts
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
- E21D20/021—Grouting with inorganic components, e.g. cement
Abstract
The invention discloses a construction method of a rock pillar supporting structure in an ultra-flat chamber, which comprises the following steps: partitioning the cross section of the cavern, separating a middle pilot tunnel, an upper pilot tunnel, a lower pilot tunnel and a lower layer reserved core rock soil, and forming a middle rock pillar through the middle pilot tunnel, the upper pilot tunnel and the lower pilot tunnel; sequentially excavating a middle pilot tunnel, an upper-layer side pilot tunnel and a lower-layer side pilot tunnel, and mounting a radial system anchor cable support structure and a radial system anchor rod support structure; digging inclined anchor cables above the middle rock pillar from middle pilot tunnels dug at two sides and upper layer side pilot tunnels, and pre-reinforcing surrounding rocks above the middle rock pillar; a transverse counter-pulling anchor rod is arranged on the middle rock pillar for reinforcement, and pre-stress is applied to the anchor rod; dismantling the middle rock pillar and installing a radial system anchor rod supporting structure at the same time; and removing the reserved core rock soil on the lower layer. According to the invention, a middle rock pillar supporting structure is reserved in the construction stage, and is combined with the local bearing arch above the pilot tunnel, so that the whole stress system of the surrounding rock is stably converted, the natural bearing arch of the surrounding rock is sealed step by step, and the safe construction of the ultra-flat cavern is realized.
Description
Technical Field
The invention relates to the technical field of building structures, in particular to a rock pillar supporting structure in an ultra-flat chamber and a construction method.
Background
In recent years, underground oil storage depots, underground tunnels, main powerhouses of hydropower stations and the like are being constructed on a large scale at home and abroad, and rock mechanics gradually becomes the key point of research on tunnels and underground engineering. The typical super-span caverns built at home and abroad mainly comprise: norwegian georgeck city skating rind, octadaling great wall station, etc. The Badaling great wall station of Jingzhang high-speed railway is a mountain underground railway station with the largest Asian scale and is also a high-speed railway underground station with the largest domestic buried depth and lifting height, the single-hole excavation span of the two end cross line sections of the Badaling great wall station reaches 32.7m, the single-arch underground excavation railway tunnel with the largest span is known in China at present, and the span of a station hall reaches 45 m.
In order to meet the increasing use requirements of underground spaces, the construction of large-span cave depots and large-span highway and railway tunnels is more and more. However, the research and engineering experience aiming at the large-span and ultra-flat cavern at present are insufficient, and the suitable stratum conditions are further researched. According to the existing design concept and civil engineering construction technology, the maximum span which can be realized by the underground excavation cavern is 10-20 m; if the span of the cavern is further increased, the primary support and the secondary lining are strengthened, and the beam column system support is additionally arranged to transmit the vault load and control the structural deformation, and the function of span reduction is realized. However, the added beam-column system cuts the cavern space, and the use requirement of large-span large-section space cannot be met. Particularly for flat non-cylindrical caverns with small rise-span ratio, the traditional design methods and concepts such as the CRD method and the neooht method cannot meet the design requirements along with the increase of the span in magnitude, and reference and guidance cannot be provided for the design methods and concepts. How design theory is improved to large-span, super flat no post hole room, how to carry out reasonable effective strut, how safe high-efficient construction becomes the problem that needs to solve urgently.
Disclosure of Invention
The invention aims to provide a rock pillar supporting structure in an ultra-flat chamber and a construction method.
In order to achieve the purpose, the concrete technical scheme of the rock pillar supporting structure in the ultra-flat chamber and the construction method is as follows:
a rock pillar supporting structure in an ultra-flat cavern, comprising: the radial system anchor cable supporting structure is provided with a plurality of anchor cables, and the anchor cables are obliquely arranged above the reserved middle rock pillar from excavated pilot tunnels at two sides; the radial system anchor rod supporting structure is provided with a plurality of anchor rods, and the anchor rods are arranged between adjacent anchor cables at intervals; the anchor rods are transversely arranged in the middle rock pillar, a local bearing arch is formed after excavation and supporting of the middle pilot tunnel and the side pilot tunnels are completed, and the surrounding rock is used for sealing the natural bearing arch step by step after the middle rock pillar is removed.
A construction method of a rock pillar supporting structure in an ultra-flat chamber comprises the following steps: partitioning the cross section of a cavern, dividing a middle pilot tunnel, an upper pilot tunnel, a lower pilot tunnel and a lower layer reserved core rock soil, and forming a middle rock pillar through the middle pilot tunnel, the upper pilot tunnel and the lower pilot tunnel; sequentially excavating a middle pilot tunnel, an upper-layer side pilot tunnel and a lower-layer side pilot tunnel, and installing a radial system anchor cable support structure and a radial system anchor rod support structure; thirdly, drilling inclined anchor cables above the middle rock pillar from middle pilot tunnels dug at two sides and upper layer side pilot tunnels, and pre-reinforcing surrounding rocks above the middle rock pillar; a transverse counter-pulling anchor rod is arranged on the middle rock pillar for reinforcement, and pre-stress is applied to the anchor rod; dismantling the middle rock pillar and installing a radial system anchor rod supporting structure at the same time; and fifthly, dismantling the reserved core rock soil on the lower layer.
The rock pillar supporting structure in the ultra-flat chamber and the construction method have the advantages that:
1) the supporting structure and the construction method of the rock pillar in the ultra-flat cavern achieve the stable conversion of the whole stress system of the surrounding rock by the temporary supporting function of the reserved rock pillar in the construction stage, and the natural bearing arch of the surrounding rock is finally closed step by step to bear all external loads; according to the invention, by innovating a design concept and improving a construction method, safe and efficient construction of the ultra-flat cavern is realized, and the cavern span can reach 30-80 m;
2) the large-space cave of the large-span pillar-free ultra-flat cavern is realized, the section clearance can be customized for specific industrial facilities and civil facilities, and the method has good social benefits and excellent popularization;
3) the safe and efficient construction method is provided for the ultra-flat cavern, the construction risk is greatly reduced, the deformation of surrounding rocks is effectively controlled, and the safety is high;
4) the self-bearing capacity of the surrounding rock is fully utilized, the surrounding rock serves as a natural bearing arch to bear all loads, supporting materials are greatly reduced, construction cost is reduced, and the self-bearing wall has good economy;
5) the construction method has clear procedures, the construction of each part is not interfered mutually, large-scale mechanized operation can be realized, the construction efficiency is high, and the practicability is better;
6) an advanced idea of realizing step-by-step closure of a natural bearing arch of the surrounding rock by reserving a middle rock pillar is provided, the design and construction level of the ultra-flat cavern in the field is greatly improved, and the original design theory is made a solid step forward;
7) reasonably partitioning the cavity cross section according to the cavity scale and the rise-span ratio; the method comprises the steps that after a middle pilot tunnel and a side pilot tunnel are excavated, an anchor rod and anchor cable system is supported in time, the suspension effect and the extrusion reinforcing arch effect of the anchor rod and the anchor cable on rock blocks are fully utilized, the slippage and looseness among the rock blocks are reduced, the overall performance of rock mass is enhanced, surrounding rocks above the pilot tunnel form a local bearing arch, an arch end is lapped on a reserved middle rock pillar and forms a temporary supporting structure system together with the reserved middle rock pillar in a construction stage, and the surrounding rocks release partial stress and deform gradually and stably in the construction stage; after the middle rock pillar is removed, the anchor rod and the anchor cable of the system are followed in time to form a new local bearing arch; the local bearing arches of all the sections are gradually connected in series and sealed to form a unified integral bearing arch, the temporary support function of the rock pillar in the construction stage is reserved, the stable conversion of the integral stress system of the surrounding rock is achieved, and the natural bearing arches of the surrounding rock are finally sealed step by step to bear all external loads.
Drawings
FIG. 1 is a construction step chart of a pilot tunnel in excavation according to the present invention;
FIG. 2 is a construction step chart of the excavation of the side guide tunnel (reserved middle rock pillar) in the invention;
FIG. 3 is a construction step chart for the demolition of a medium rock pillar according to the present invention;
FIG. 4 is a construction step chart of the invention with the medium pillar completely removed;
FIG. 5 is a process diagram illustrating the completion of the excavation of the ultra-flat chamber of the present invention;
FIG. 6A is a first schematic plan view of a rock pillar excavation scheme according to the present invention;
FIG. 6B is a schematic plan view of a second embodiment of the rock pillar excavation scheme of the present invention;
FIG. 6C is a third schematic plan view of a rock pillar excavation scheme according to the present invention;
FIG. 6D is a fourth schematic plan view of a rock pillar excavation scheme according to the present invention.
In the figure: 11. a first middle pilot hole; 12. a second middle pilot hole; 21. a first upper-layer side guide hole 21; 22. a second upper layer side guide hole; 31. a first lower layer side guide hole; 32. a second lower layer edge guide hole; 41. a first middle rock pillar; 42. a second middle rock pillar; 43. a third middle rock pillar; 51. a local area load bearing arch; 52. enclosing rocks step by step to seal the natural bearing arch after the middle rock pillar is removed; 6. the lower layer is reserved with core rock soil, 7, a radial system anchor cable supporting structure, 8, a radial system anchor rod supporting structure, 9, an anchor cable, 10 and an anchor rod.
Detailed Description
In order to better understand the purpose, structure and function of the present invention, the following will describe in detail a rock pillar supporting structure in an ultra-flat cavity and a construction method thereof in conjunction with the accompanying drawings.
As shown in fig. 1 to 6D, which illustrate a rock pillar supporting structure in an ultra-flat cavern and a construction method thereof, the supporting structure comprises a radial system anchor cable supporting structure 7, a radial system anchor rod supporting structure 8, anchor cables 9 and anchor rods 10, wherein the radial system anchor cable supporting structure 7 is provided with a plurality of anchor cables 9, and the anchor cables 9 are obliquely arranged above a reserved rock pillar 4 from excavated pilot tunnels (middle pilot tunnels 1) on two sides; the radial system anchor rod supporting structure 8 is provided with a plurality of anchor rods, and the anchor rods are arranged between the adjacent anchor cables 9 at intervals; the transverse anchor rods 10 are arranged in the middle rock pillar 4 in a split manner; after excavation and support of the middle pilot tunnel, the upper layer side pilot tunnel and the lower layer side pilot tunnel are completed, a local bearing arch 51 is formed, and after the middle rock pillar 4 is removed, the surrounding rocks close the natural bearing arch 52 step by step.
The length of each anchor rod in the radial system anchor rod supporting structure 8 is 3 m-10 m, and the circumferential and longitudinal intervals of adjacent anchor rods are 1 m-3 m. In addition, the length of the anchor cable 9 in the anchor cable supporting structure 7 of the radial system is 15 m-35 m, the circumferential and longitudinal distance between adjacent anchor cables 9 is 4 m-8 m, and the prestress is 1000 kN-2500 kN.
The vector-span ratio of the ultra-flat cavern is less than 1, the span can reach 30-80 m, and the ultra-flat cavern is suitable for II-IV hard rock strata with side pressure coefficients of 1-3. The invention is applied to a grade III granite stratum of an ultra-flat chamber as an example, the lateral pressure coefficient is 2.0, and the site has no confined water. The cavern is oval, the span is 58m, the maximum height is 14.5m, the vector-to-span ratio is 0.25, and the longitudinal length is 125 m. 6 through cracks exist in the range of the cavern, the through cracks are basically orthogonal to the axis of the cavern, and the dip angles of the cracks are 60-90 degrees and are all steep dip angle cracks.
The invention also discloses a construction method of the rock pillar supporting structure in the ultra-flat chamber, which comprises the following steps:
the method comprises the following steps of firstly, partitioning the cross section of a cavern, dividing a middle pilot tunnel, an upper pilot tunnel, a lower pilot tunnel and a lower layer reserved core rock soil, and forming a middle rock pillar through the middle pilot tunnel, the upper pilot tunnel and the lower pilot tunnel.
Specifically, the cross section of the cavern is reasonably partitioned according to the size and the midspan ratio of the cavern, and the middle pilot tunnel is divided into a first middle pilot tunnel 11 and a second middle pilot tunnel 12 which are positioned on the left side and the right side; dividing the upper layer side pilot hole into a first upper layer side pilot hole 21 and a second upper layer side pilot hole 22 which are positioned at the left side and the right side; the lower layer side pilot hole is located at the bottom of the upper layer side pilot hole and comprises a first lower layer side pilot hole 31 and a second lower layer side pilot hole 32 which are respectively located at the bottoms of the first upper layer side pilot hole 21 and the second upper layer side pilot hole 22, and the widths of the middle pilot hole, the upper pilot hole and the lower pilot hole are all 8-12 m (preferably 10 m).
In addition, the number of the medium rock pillars is determined according to the chamber span, and at least one group is preferably arranged in the invention. Specifically, the middle rock pillar is divided into a first middle rock pillar 41, a second middle rock pillar 42 and a third middle rock pillar 43, the first middle rock pillar 41 is located between the first middle pilot tunnel 11 and the first upper layer side pilot tunnel 22, the second middle rock pillar 42 is located between the first middle pilot tunnel 11 and the second middle pilot tunnel 12, the third middle rock pillar 43 is located between the second middle pilot tunnel 12 and the second upper layer side pilot tunnel 22, and the width of the middle rock pillar is 3-10 m (preferably 6 m).
In addition, the lower reserved core rock soil 6 is positioned between the lower side pilot tunnels on the left side and the right side and at the bottom of the middle pilot tunnel, the width is 36-40 m (preferably 38m), the height is 7-9 m (preferably 8m), and the total width of the section is 56-60 m (preferably 58 m).
And step two, as shown in fig. 1, excavating a middle pilot tunnel and an upper layer side pilot tunnel, and then excavating a lower layer side pilot tunnel.
Specifically, a first middle pilot tunnel 11 and a second middle pilot tunnel 12 are excavated through blasting, then a first upper layer side pilot tunnel 21 and a second upper layer side pilot tunnel 22 on the left side and the right side are excavated in sequence, the longitudinal distance between the tunnel faces is larger than 10m, and the blasting vibration speed is strictly controlled.
Then, as shown in fig. 2, a lower-layer side pilot hole is excavated.
Specifically, after the areas of the first middle pilot tunnel 11, the second middle pilot tunnel 12, the first upper side pilot tunnel 21 and the second upper side pilot tunnel 22 are all excavated, the first lower side pilot tunnel 31 and the second lower side pilot tunnel 32 located on the left and right sides are excavated in sequence, and at this time, four groups of parallel pilot tunnels supported and separated by the first middle rock pillar 41, the second middle rock pillar 42 and the third middle rock pillar 43 are formed.
Meanwhile, in the pilot tunnel excavation process of the middle pilot tunnel, the upper-layer side pilot tunnel and the lower-layer side pilot tunnel, the radial system anchor cable supporting structure 7 and the radial system anchor rod supporting structure 8 are installed in time to be combined for supporting.
The length of the anchor cable supporting structure 7 of the radial system is 15-35 m (preferably 20m), the circumferential and longitudinal spacing is 4-8 m (preferably 6m), and the prestress is 1000-2500 kN (preferably 1200 kN); the length of the radial system anchor rod supporting structure 8 is 3 m-10 m (preferably 6m), the circumferential and longitudinal distance is 1 m-3 m (preferably 1.5m), and a common mortar anchor rod is adopted. Partial stress is released by rock bodies in the pilot tunnel excavation process, meanwhile, the self-bearing capacity of surrounding rocks is fully utilized, and the surrounding rocks form a local bearing arch 5 through a combined supporting mode of a system anchor rope 7 and a system anchor rod 8.
And thirdly, drilling inclined anchor cables 9 above the middle rock pillar from the middle pilot tunnels and the upper layer side pilot tunnels dug at the two sides so as to pre-reinforce the surrounding rock above the middle rock pillar, and serially suspending key blocks possibly appearing in the surrounding rock to form a protective umbrella during later dismantling of the middle rock pillar. Meanwhile, the middle rock pillar is drilled with a transverse counter-pulling anchor rod 10 for reinforcement, pre-stress of 90-110 kN (preferably 100kN) is applied to the anchor rod 10, the stress state of the middle rock pillar is improved, and the annular overall performance of the middle rock pillar is enhanced.
Specifically, in the present invention, the first middle rock pillar 41, the second middle rock pillar 42 and the third middle rock pillar 43 need to be drilled with a transverse tie-bolt 10 for reinforcement.
And step four, dismantling the middle rock pillar and installing the radial system anchor rod supporting structure 8 at the same time.
Specifically, as shown in fig. 6C, a working surface is opened up by the front and rear ends of the cavern, the second middle rock pillar 42 is firstly removed section by section from the left and right sides to the middle, the length of each section of the second middle rock pillar 42 is 4m to 6m (preferably 5m), monitoring measurement is enhanced in the process of removing the second middle rock pillar 42, the surrounding rock can be continuously removed after being deformed stably, the surrounding rock of the cavern is gradually changed into a space stress state from a transverse stress state, and rough blasting and large-scale removal are strictly prohibited; and as shown in fig. 6D, the first middle rock pillar 41 and the third middle rock pillar 42 are sequentially split in pairs, and the longitudinal distance between the splitting surfaces of the first middle rock pillar 41 and the third middle rock pillar 42 is larger than 15 m.
And meanwhile, constructing a radial system anchor rod supporting structure 8 above the dismantling section of the middle rock pillar in time. By reinforcing surrounding rock above the middle rock pillar in time, the reinforcing body and the local bearing arch 5 are in seamless connection, the natural bearing arch 52 of the surrounding rock is closed, and the outer ring of the cavern forms an annular self-bearing arch structure of the surrounding rock.
The length of the anchor rod in the radial system anchor rod supporting structure 8 is 3 m-10 m (preferably 6m), the circumferential and longitudinal intervals are 1 m-3 m (preferably 1.5m), and a common mortar anchor rod is adopted.
And fifthly, removing the reserved core rock soil 6 on the lower layer, and finishing excavation of the cavern.
Through the steps, the stable conversion of the whole stress system of the surrounding rock is achieved through the combined action of the reserved middle rock pillar supporting structure and the local bearing arch above the pilot tunnel in the construction stage, the natural bearing arch of the surrounding rock is sealed step by step, and the safe and efficient construction of the ultra-flat cavern is realized.
According to the rock pillar supporting structure in the ultra-flat cavern and the construction method, the temporary supporting function of the rock pillar in the construction stage is reserved, so that the stable conversion of the whole stress system of the surrounding rock is achieved, and the natural bearing arch of the surrounding rock is finally closed step by step to bear all external loads; according to the invention, by innovating a design concept and improving a construction method, safe and efficient construction of the ultra-flat cavern is realized, and the cavern span can reach 30-80 m; the large-space cave of the large-span pillar-free ultra-flat cavern is realized, the section clearance can be customized for specific industrial facilities and civil facilities, and the method has good social benefits and excellent popularization; the safe and efficient construction method is provided for the ultra-flat cavern, the construction risk is greatly reduced, the deformation of surrounding rocks is effectively controlled, and the safety is high; the self-bearing capacity of the surrounding rock is fully utilized, the surrounding rock serves as a natural bearing arch to bear all loads, supporting materials are greatly reduced, construction cost is reduced, and the self-bearing wall has good economy; the construction method has clear procedures, the construction of each part is not interfered mutually, large-scale mechanized operation can be realized, the construction efficiency is high, and the practicability is better; an advanced idea of realizing step-by-step closure of a natural bearing arch of the surrounding rock by reserving a middle rock pillar is provided, the design and construction level of the ultra-flat cavern in the field is greatly improved, and the original design theory is made a solid step forward; reasonably partitioning the cavity cross section according to the cavity scale and the rise-span ratio; the method comprises the steps that after a middle pilot tunnel and a side pilot tunnel are excavated, an anchor rod and anchor cable system is supported in time, the suspension effect and the extrusion reinforcing arch effect of the anchor rod and the anchor cable on rock blocks are fully utilized, the slippage and looseness among the rock blocks are reduced, the overall performance of rock mass is enhanced, surrounding rocks above the pilot tunnel form a local bearing arch, an arch end is lapped on a reserved middle rock pillar and forms a temporary supporting structure system together with the reserved middle rock pillar in a construction stage, and the surrounding rocks release partial stress and deform gradually and stably in the construction stage; after the middle rock pillar is removed, the anchor rod and the anchor cable of the system are followed in time to form a new local bearing arch; the local bearing arches of all the sections are gradually connected in series and sealed to form a unified integral bearing arch, the temporary support function of the rock pillar in the construction stage is reserved, the stable conversion of the integral stress system of the surrounding rock is achieved, and the natural bearing arches of the surrounding rock are finally sealed step by step to bear all external loads.
The present invention has been further described with reference to specific embodiments, but it should be understood that the detailed description should not be construed as limiting the spirit and scope of the present invention, and various modifications made to the above-described embodiments by those of ordinary skill in the art after reading this specification are within the scope of the present invention.
Claims (9)
1. The utility model provides a rock pillar supporting construction in super flat cavity which characterized in that includes:
the radial system anchor cable supporting structure (7) is provided with a plurality of anchor cables (9), and the anchor cables (9) are obliquely arranged above the reserved middle rock pillar from excavated pilot tunnels on two sides;
the radial system anchor rod supporting structure (8) is provided with a plurality of anchor rods, and the anchor rods are arranged between adjacent anchor cables (9) at intervals;
and the anchor rods (10) are transversely arranged in the middle rock pillar, a local bearing arch (5) is formed after excavation and supporting of the middle pilot tunnel and the side pilot tunnel are completed, and the natural bearing arch (52) is closed by surrounding rocks step by step after the middle rock pillar is removed.
2. The support structure according to claim 1, characterized in that the length of the anchor rods in the radial system bolting structure (8) is 3m to 10m, and the circumferential, longitudinal spacing of adjacent anchor rods is 1m to 3 m.
3. The support structure according to claim 1, wherein the length of the anchor cables (9) in the radial system anchor cable support structure (7) is 15m to 35m, the circumferential and longitudinal spacing of adjacent anchor cables (9) is 4m to 8m, and the pre-load is 1000kN to 2500 kN.
4. A construction method of a rock pillar supporting structure in an ultra-flat chamber is characterized by comprising the following steps:
partitioning the cross section of a cavern, dividing a middle pilot tunnel, an upper pilot tunnel, a lower pilot tunnel and a lower layer reserved core rock soil, and forming a middle rock pillar through the middle pilot tunnel, the upper pilot tunnel and the lower pilot tunnel;
sequentially excavating a middle pilot tunnel, an upper-layer side pilot tunnel and a lower-layer side pilot tunnel, and installing a radial system anchor cable support structure and a radial system anchor rod support structure;
thirdly, drilling inclined anchor cables above the middle rock pillar from middle pilot tunnels dug at two sides and upper layer side pilot tunnels, and pre-reinforcing surrounding rocks above the middle rock pillar; a transverse counter-pulling anchor rod is arranged on the middle rock pillar for reinforcement, and pre-stress is applied to the anchor rod;
dismantling the middle rock pillar and installing a radial system anchor rod supporting structure at the same time;
and fifthly, dismantling the reserved core rock soil on the lower layer.
5. The construction method according to claim 4, wherein in step one:
dividing the middle pilot tunnel into a first middle pilot tunnel (11) and a second middle pilot tunnel (12) which are positioned at the left side and the right side;
the upper layer side guide holes are respectively positioned at a first upper layer side guide hole (21) and a second upper layer side guide hole (22) on the left side and the right side;
the lower layer side guide hole is positioned at the bottom of the upper layer side guide hole and is divided into a first lower layer side guide hole (31) and a second lower layer side guide hole (32) which are respectively positioned at the bottoms of the first upper layer side guide hole (21) and the second upper layer side guide hole (22).
6. The construction method according to claim 4, wherein in step one: dividing the middle rock pillar into:
a first middle rock pillar (41) located between the first middle pilot hole (11) and the first upper layer side pilot hole (22);
a second central rock pillar (42) located between the first central pilot tunnel (11) and the second central pilot tunnel (12);
and a third middle rock pillar (43) positioned between the second middle pilot hole (12) and the second upper layer side pilot hole (22).
7. The construction method according to claim 6, wherein in step four: the working face is opened up by the front end and the rear end of the cavern, the second middle rock pillar (42) is firstly dismantled section by section from two sides to the middle, and then the first middle rock pillar (41) and the third middle rock pillar (42) are dismantled in sequence.
8. Construction method according to claim 7, characterized in that the longitudinal distance of the dismantling faces of the first (41) and third (42) medium rock pillars in pairs is greater than 15 m.
9. The construction method according to claim 1, characterized in that in step four, a radial system anchor rod supporting structure (8) above the demolition section of the middle rock pillar is constructed, the reinforcing body is seamlessly jointed with the local bearing arch (5) by reinforcing the surrounding rock above the middle rock pillar, the natural bearing arch (52) of the surrounding rock is closed, and the outer ring of the cavern forms a circumferential self-bearing arch structure of the surrounding rock.
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| CN202010110393.7A CN111206950A (en) | 2020-02-22 | 2020-02-22 | Rock pillar supporting structure in ultra-flat chamber and construction method |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112240207A (en) * | 2020-09-18 | 2021-01-19 | 中铁隧道集团一处有限公司 | Jumbo-span cave depot lattice jumping excavation and rapid bottom turning method |
| CN112610250A (en) * | 2020-12-14 | 2021-04-06 | 中铁隧道局集团有限公司 | Method for dismantling three rock pillar supports of large-span underground cave depot |
| CN112832778A (en) * | 2021-01-28 | 2021-05-25 | 河南理工大学 | Construction structure and construction method of medium-hardness and hard surrounding rock super-large section tunnel |
| CN112901182A (en) * | 2021-02-03 | 2021-06-04 | 中铁隧道局集团有限公司 | Eight-part excavation construction method for reserving double rock pillar supports in large-span underground cave depot |
| CN115094849A (en) * | 2022-07-05 | 2022-09-23 | 中铁建大桥工程局集团第五工程有限公司 | Anchor cable supporting method for cross section of diversion tunnel |
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2020
- 2020-02-22 CN CN202010110393.7A patent/CN111206950A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112240207A (en) * | 2020-09-18 | 2021-01-19 | 中铁隧道集团一处有限公司 | Jumbo-span cave depot lattice jumping excavation and rapid bottom turning method |
| CN112240207B (en) * | 2020-09-18 | 2022-02-08 | 中铁隧道集团一处有限公司 | Jumbo-span cave depot lattice jumping excavation and rapid bottom turning method |
| CN112610250A (en) * | 2020-12-14 | 2021-04-06 | 中铁隧道局集团有限公司 | Method for dismantling three rock pillar supports of large-span underground cave depot |
| CN112610250B (en) * | 2020-12-14 | 2021-12-24 | 中铁隧道局集团有限公司 | Method for dismantling three rock pillar supports of large-span underground cave depot |
| CN112832778A (en) * | 2021-01-28 | 2021-05-25 | 河南理工大学 | Construction structure and construction method of medium-hardness and hard surrounding rock super-large section tunnel |
| CN112901182A (en) * | 2021-02-03 | 2021-06-04 | 中铁隧道局集团有限公司 | Eight-part excavation construction method for reserving double rock pillar supports in large-span underground cave depot |
| CN115094849A (en) * | 2022-07-05 | 2022-09-23 | 中铁建大桥工程局集团第五工程有限公司 | Anchor cable supporting method for cross section of diversion tunnel |
| CN115094849B (en) * | 2022-07-05 | 2023-09-08 | 中铁建大桥工程局集团第五工程有限公司 | Anchor cable supporting method for intersection section of diversion tunnel |
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