In-roadway special-shaped pier column and roadway supporting method

Abstract

The invention relates to the technical field of roadway supporting, and provides an in-roadway special-shaped pier column and a roadway supporting method.The in-roadway special-shaped pier column comprises a column body formed through pouring and a roof-contacted supporting body, the column body is arranged in the height direction of a roadway, and the roof-contacted supporting body is located above the column body and suitable for making contact with a roadway roof; the supporting area of the roof-contacted supporting body is larger than that of the column body. Wherein the roof-contacted supporting body is provided with a roof-contacted surface, a first cambered surface, a second cambered surface and a third cambered surface, the first cambered surface and the second cambered surface are symmetrically arranged on the two sides of the roof-contacted surface, the first cambered surface and the second cambered surface are sunken towards the center of the roof-contacted supporting body, and the third cambered surface is connected with the roof-contacted surface, the first cambered surface and the second cambered surface. The third cambered surface protrudes towards the direction away from the center of the roof-contacted supporting body. According to the in-roadway special-shaped pier column, a wide-end-up special-shaped bearing structure is adopted, the top supporting area is increased, the occupied space of a roadway is reduced, the requirement for auxiliary transportation can be met, and the supporting effect of soft rock broken surrounding rock can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel support, and in particular to a special-shaped pier in a tunnel and a tunnel support method. Background Art

[0002] For the top and bottom rock layers of the working face, which are mostly weakly cemented soft rocks, the degree of cementation is poor, and the sanding, mudding and disintegration are obvious when encountering water. In addition, affected by the "three highs and one disturbance", the large deformation problem of the surrounding rock of the soft rock tunnel is prominent.

[0003] Therefore, the method of "reverse bottom arch + full-section grouting" is often used to control the large deformation of the surrounding rock, which can achieve certain results, especially during the excavation period. However, during the mining period and the process of leaving the tunnel along the goaf, the surrounding rock of the tunnel still deforms violently due to the influence of mining stress, which seriously affects production safety.

[0004] In the related technology, the tunnel support adopts unit brackets and single pillars for auxiliary support, which can solve the problem of tunnel surrounding rock deformation, but there are problems of low support resistance and high support cost, and the support distance is too long, which affects the tunnel auxiliary transportation. Summary of the invention

[0005] The present invention provides a special-shaped pier in a tunnel and a tunnel support method to solve the above-mentioned technical defects in the prior art. The special-shaped pier in the tunnel adopts a special-shaped bearing structure that is wide at the top and narrow at the bottom, which increases the top support area and reduces the space occupied by the tunnel. It can not only meet the requirements of auxiliary transportation, but also increase the support effect of soft rock and broken surrounding rock.

[0006] A first aspect of the present invention provides a special-shaped pier in a lane, comprising a cast column and a top support body, wherein the column is arranged along the height direction of the lane, the top support body is located above the column, and the support area of ​​the top support body is larger than the support area of ​​the column; Wherein, the top support body has a top surface, a first curved surface, a second curved surface and a third curved surface, the first curved surface and the second curved surface are symmetrically arranged on both sides of the top surface, the first curved surface and the second curved surface are recessed toward the center of the top support body, the third curved surface is respectively connected to the top surface, the first curved surface and the second curved surface, and the third curved surface protrudes away from the center direction of the top support body.

[0007] According to the special-shaped pier in the lane provided by the present invention, the top-jointing supporting body has side surfaces, the side surfaces are respectively connected to the top-jointing surface, the first curved surface and the second curved surface, and the side surfaces are arranged opposite to the third curved surface; The side surface is a plane flush with the vertical direction, or the side surface is an inclined surface extending obliquely upward.

[0008] According to the special-shaped pier in the tunnel provided by the present invention, the length of the column is L1, and the length of the top support body is L2, wherein: L2 is greater than or equal to 2 times of L1.

[0009] According to the special-shaped pier column in the tunnel provided by the present invention, the width of the column body is B1, and the width of the top support body is B2, wherein: B2 is greater than B1, and B2 is less than or equal to 2 times of B1.

[0010] According to the special-shaped pier in the lane provided by the present invention, the height of the column is H1, and the height of the top support body is H2, wherein: H2 is equal to one sixth of H1.

[0011] According to the special-shaped pier in the lane provided by the present invention, the length of the top edge of the first curved surface and the second curved surface is W1, and the length of the bottom edge of the first curved surface and the second curved surface is W2, wherein: W2 is greater than W1, and W2 is less than or equal to 2 times of W1; In the orthographic projection view, the radius R of the third arc surface is equal to half of W2.

[0012] A second aspect of the present invention provides a tunnel support method based on any one of the special-shaped piers in the tunnel, comprising the following steps: Hardening the base plate: The floor of the preset thickness is constructed and concrete is poured. The poured concrete hardens to form the target base plate. Laying out the mold: assembling a rigid mold on the target bottom plate, and laying out a steel skeleton in the rigid mold so that the steel skeleton extends out of the rigid mold, and then assembling a flexible top template above the rigid mold; Casting and forming: pouring concrete into the rigid mold and the flexible top template; Removing the mold: After ensuring that the concrete in the rigid mold and the flexible top mold is completely solidified, the rigid mold is removed.

[0013] According to the tunnel support method based on special-shaped piers in the tunnel provided by the present invention, pouring concrete into the rigid mold and the flexible top template includes: A concrete pump or a mortar pump is used to pour concrete into the rigid mold and the flexible top template. The pumped grout can be of a strength higher than C30 concrete and M30 mortar. The height of the pump port from the target bottom plate is 1m to 1.5m.

[0014] According to the tunnel support method based on special-shaped piers in the tunnel provided by the present invention, during the process of arranging the molds, the center distance between two adjacent rigid molds is 2m to 4m.

[0015] According to the tunnel support method based on special-shaped piers in the tunnel provided by the present invention, the process of casting and forming the special-shaped piers is carried out at a position greater than or equal to 100m from the lagging excavation working face or after the tunnel excavation is completed.

[0016] The special-shaped pier column in the tunnel provided by the present invention is provided with a cast column body and a top support body. The column body is arranged along the height direction of the tunnel. The top support body is located above the column body and is suitable for contacting the tunnel roof. The support area of ​​the top support body is larger than the support area of ​​the column body, and the top support body has a top surface, a first curved surface, a second curved surface and a third curved surface. The first curved surface and the second curved surface are symmetrically arranged on both sides of the top surface, the first curved surface and the second curved surface are recessed in the center of the top support body, and the third curved surface is respectively connected to the top surface, the first curved surface and the second curved surface, and the third curved surface is convex toward the center direction away from the top support body.

[0017] The special-shaped piers in the tunnel adopt a special-shaped bearing structure that is wide at the top and narrow at the bottom, which increases the top support area and reduces the space occupied by the tunnel. It can not only meet the requirements of auxiliary transportation, but also increase the support effect of soft rock and broken surrounding rock. The third arc surface of the top support body forms a convex external contour, which is conducive to dispersing and transferring the load transmitted by the roof, reducing stress concentration and improving the overall support effect. The column realizes the stress transmission of the soft rock tunnel, which can not only indirectly support the roof, but also strongly support the bottom plate, and the support effect is significant. In the case of broken or weak coal seam roof, special-shaped piers are suitable for improving the reliability and safety of tunnel support and reducing the probability of roof collapse accidents. It can operate in parallel with the mining face, with high support efficiency and relatively simple support process.

[0018] The tunnel support method based on special-shaped piers in the tunnel provided by the embodiment of the present invention is designed to solve the problems of continuous deterioration of surrounding rock conditions in soft rock tunnels under the action of rheology and creep, especially large deformation of roof and floor plates under the influence of mining dynamic pressure. It can improve the support strength and support effect of soft rock tunnels, improve the control effect and efficiency of deformation of surrounding rock in soft rock tunnels, and reduce the control cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic structural diagram of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0021] Figure 2 It is a front view of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0022] Figure 3 It is a side view of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0023] Figure 4 It is a top view of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0024] Figure 5 It is a cross-sectional view of a tunnel support of a special-shaped pier provided in an embodiment of the present invention.

[0025] Figure 6 It is a schematic flow chart of the tunnel support method provided in an embodiment of the present invention.

[0026] Reference numerals: 10. Column; 20. Top support body; 21. Top surface; 22. First curved surface; 23. Second curved surface; 24. Third curved surface; 25. Side surface. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0029] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] Figure 1 It is a schematic structural diagram of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0032] See also Figure 1 The embodiment of the present invention provides a special-shaped pier in a tunnel, which can meet the needs of tunnel reinforcement under complex geological conditions, especially for supporting unstable rock formations at the top. The special-shaped pier in the tunnel includes a cast column 10 and a top support body 20. The column 10 is arranged along the height direction of the tunnel, plays a basic support role, can provide rigid resistance in the vertical direction, absorb the load from the ground pressure, and prevent the tunnel wall from collapsing. The top support body 20 is located above the column 10 and is suitable for contacting the tunnel roof. The support area of ​​the top support body 20 is larger than the support area of ​​the column 10, that is, the cross-sectional area of ​​the top support body 20 is larger than the cross-sectional area of ​​the column 10. The support area of ​​the top support body 20 is larger than that of the column 10. The top support body 20 is used to expand the support range and complement the column 10, so as to provide a wider range of support in the unstable area at the top of the tunnel.

[0033] Among them, the top support body 20 has a top surface 21, a first curved surface 22, a second curved surface 23 and a third curved surface 24. The first curved surface 22 and the second curved surface 23 are symmetrically arranged on both sides of the top surface 21. The first curved surface 22 and the second curved surface 23 are recessed toward the center of the top support body 20. The third curved surface 24 is respectively connected to the top surface 21, the first curved surface 22 and the second curved surface 23. The third curved surface 24 protrudes away from the center direction of the top support body 20.

[0034] The top surface 21 is in direct contact with the tunnel roof, bearing the direct pressure from the roof. The first curved surface 22 and the second curved surface 23, which are concave inward, form a natural wedge-shaped structure, which helps to improve the bite force between the top support body 20 and the surrounding rocks, plays a certain anchoring role, and enhances stability. The third curved surface 24 forms a convex external contour, which is conducive to dispersing and transferring the load transmitted by the roof, reducing stress concentration, and improving the overall support effect. That is, the convex design of the third curved surface 24 effectively diffuses the roof load to the surrounding areas, reducing the damage that may be caused by excessive stress at a single point.

[0035] It can be understood that the special-shaped pier in the tunnel provided by the embodiment of the present invention is provided with a cast column 10 and a top support body 20. The column 10 is arranged along the height direction of the tunnel, and the top support body 20 is located above the column 10 and is suitable for contacting the tunnel roof. The support area of ​​the top support body 20 is larger than the support area of ​​the column 10, and the top support body 20 has a top surface 21, a first curved surface 22, a second curved surface 23 and a third curved surface 24. The first curved surface 22 and the second curved surface 23 are symmetrically arranged on both sides of the top surface 21, the first curved surface 22 and the second curved surface 23 are recessed toward the center of the top support body 20, the third curved surface 24 is respectively connected to the top surface 21, the first curved surface 22 and the second curved surface 23, and the third curved surface 24 is convex in the direction away from the center of the top support body 20.

[0036] The special-shaped piers in the tunnel adopt a special-shaped bearing structure that is wide at the top and narrow at the bottom, which increases the top support area and reduces the space occupied by the tunnel. It can not only meet the requirements of auxiliary transportation, but also increase the support effect of soft rock and broken surrounding rock. The third arc surface 24 of the top support body 20 forms a convex external contour, which is conducive to dispersing and transferring the load transmitted by the roof, reducing stress concentration, and improving the overall support effect; the column 10 realizes the stress transfer of the soft rock tunnel, which can not only indirectly support the roof, but also strongly support the bottom plate, and the support effect is significant. In the face of broken or weak coal seam roof, special-shaped piers are suitable for improving the reliability and safety of tunnel support and reducing the probability of roof collapse accidents. It can operate in parallel with the mining face, with high support efficiency and relatively simple support process.

[0037] Continue reading Figure 1 In some embodiments of the present invention, the top support body 20 has a side surface 25, and the side surface 25 is respectively connected to the top surface 21, the first curved surface 22 and the second curved surface 23, and the side surface 25 is arranged back to back with the third curved surface 24; the side surface 25 is a plane flush with the vertical direction, or the side surface 25 is an inclined surface extending obliquely upward.

[0038] The side surface 25 is an important component of the top-connecting support body 20 , which is connected with the top-connecting surface 21 , the first curved surface 22 and the second curved surface 23 , forming the rear support of the support system.

[0039] When the side 25 adopts a plane design parallel to the vertical direction, it can provide additional support in the horizontal direction, which is suitable for the relatively stable rock formations on both sides of the tunnel. Through the straight interface, it ensures the close connection between the support system and the tunnel wall, reducing the risk of lateral displacement.

[0040] When the side surface 25 is an inclined surface extending upward, compared with a plane design, the introduction of the inclined surface brings greater flexibility to the top support body 20. It is suitable for situations where the top of the tunnel is inclined or unstable, and can automatically adjust the angle as the geological conditions change, effectively offsetting the pushing force from the top rock layer.

[0041] Figure 2 It is a front view of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0042] See also Figure 2 In some embodiments of the present invention, the width of the column 10 is L1, and the width of the top support body 20 is L2, wherein: L2 is greater than or equal to 2 times of L1.

[0043] Equivalently, by setting L2≥2L1, a structure is created that can effectively share the top load and maximize the internal space of the tunnel. The design of the top support body 20 being wider than the column 10 is intended to increase the contact area between the top support body 20 and the tunnel roof, thereby better dispersing the pressure from the roof, reducing stress concentration, and improving the bearing capacity of the entire support system.

[0044] For example, in a deep coal mining environment, the roof rock is usually under tremendous pressure and prone to collapse. The widened top support body 20 can not only effectively withstand the impact of the roof, but also because of its wide design, it can evenly distribute the load over a larger area, reduce the stress per unit area, and reduce the generation of cracks. The wide-width top support body 20 is like a large and stable umbrella, providing a more reliable coverage for the tunnel and reducing the possibility of roof falls and spalling accidents. Although the top support body 20 increases the occupied volume, the reduced volume of the column 10 structure makes the internal available space more spacious, thereby improving operational efficiency. Since the force is more balanced, the wear of the support structure is reduced, reducing the cost and frequency of regular maintenance and replacement.

[0045] Among them, L1 can be 600mm, and L2 can be 1500mm.

[0046] Figure 3 It is a side view of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0047] See also Figure 3 In some embodiments of the present invention, the width of the column 10 is B1, and the width of the top support body 20 is B2, wherein: B2 is greater than B1, and B2 is less than or equal to 2 times of B1.

[0048] In other words, the embodiment of the present invention aims to strengthen the support strength of the roof area by widening the top support body 20 to at least exceed the width of the column 10, thereby protecting the tunnel from the threat of top collapse. At the same time, the width of the top support body 20 is limited to no more than twice the width of the column 10 to avoid excessive occupation of limited space resources and ensure that the interior of the tunnel is wide enough to facilitate ventilation, transportation and personnel activities.

[0049] For example, in a mining environment, especially when working at depth, the stability of the roof is crucial. B2>B1 ensures that even in a high-pressure environment, the roof support body 20 can provide sufficient coverage to prevent rock strata from sliding, and its width is controlled within 2B1, which ensures the smooth flow between the goaf and the working channel, without affecting the entry and exit of mechanical equipment and the transportation of ore.

[0050] Among them, B1 can be 600mm, and B2 can be 1000mm.

[0051] Continue reading Figure 2 and Figure 3 In some embodiments of the present invention, the height of the column 10 is H1, and the height of the top support body 20 is H2, wherein: H2 is equal to one sixth of H1, that is, H1 is 6 times H2.

[0052] That is, the height of the column 10 is at least six times the height of the top support body 20, in order to improve the support effect while avoiding excessive occupation of limited space resources.

[0053] For example: in mines with depths of hundreds of meters or even kilometers, the roof pressure is extremely high. The design standard of H1 ≥ 6H2 can ensure that the top area has sufficient strength to withstand the heavy pressure of rocks, while providing a stable working environment for the working area below, reducing accidents caused by roof problems, maintaining good space utilization, and optimizing the internal space layout.

[0054] Among them, H1 can be 3000mm, and H2 can be 500mm.

[0055] Figure 4 It is a top view of a special-shaped pier in a lane provided by an embodiment of the present invention.

[0056] See also Figure 4In some embodiments of the present invention, the length of the top edge of the first curved surface 22 and the second curved surface 23 is W1, and the length of the bottom edge of the first curved surface 22 and the second curved surface 23 is W2, wherein: W2 is greater than W1, and W2 is less than or equal to 2 times W1; in the orthographic projection view, the radius R of the third curved surface 24 is equal to half of W2.

[0057] This is equivalent to the length of the top edge (W1) to the bottom edge (W2) of the first curved surface 22 and the second curved surface 23 gradually increasing to form a gradual transition, so that the top support body 20 can achieve a smooth transition between the top and the bottom, which not only increases the contact area but also optimizes the load distribution. The third curved surface 24 is designed as an arc with a radius R equal to half of W2, which can effectively disperse the top surface pressure, avoid stress concentration, and improve the bending resistance and toughness of the top support body 20.

[0058] Through gradient change and curvature design, the top support body 20 achieves uniform distribution of top pressure, reducing the risk of fracture or deformation. Combined with the arc-shaped third curved surface 24, both strength and lightness are taken into account, thereby improving the comprehensive performance of the top support body 20.

[0059] For example, in coal mining, by designing the bottom length W2 of the first arc surface 22 and the second arc surface 23 to be slightly larger than the top W1, the contact area between the top support body 20 and the roof can be effectively increased. At the same time, the arc-shaped third arc surface 24 further optimizes the pressure-bearing capacity, significantly improving the overall safety of the tunnel.

[0060] The top edge W1 of the first curved surface 22 and the second curved surface 23 may be 600 mm, and the bottom edge W2 of the first curved surface 22 and the second curved surface 23 may be 1000 mm. The radius R of the third curved surface 24 may be 500 mm.

[0061] Figure 5 It is a cross-sectional view of a tunnel support of a special-shaped pier provided in an embodiment of the present invention.

[0062] See also Figure 5 It should be noted that the special-shaped piers provided in the embodiments of the present invention are not only used for reinforced support during excavation and mining of soft rock tunnels, but can also be used for reinforced support of deep mining mines, high-pressure tunnels and goaf-side tunnels, all of which have significant economic and social benefits.

[0063] For example, in the tunnel support cross-section diagram of the special-shaped pier, a tunnel driving side is formed on one side of the special-shaped pier, and the width of the tunnel driving side can be 3000mm, and a tunnel pedestrian side is formed on the other side of the special-shaped pier, and the width of the tunnel pedestrian side can be 2000mm.

[0064] Figure 6It is a schematic flow chart of the tunnel support method provided in an embodiment of the present invention.

[0065] See also Figure 6 An embodiment of the present invention provides a tunnel support method based on special-shaped piers in the tunnel, including the following steps S100, S200, S300 and S400.

[0066] Step S100: Hardening the bottom plate: The floor of the preset thickness is raised and concrete is poured. The poured concrete is hardened to form the target bottom plate. In order to reduce the amount of raised bottom and poured, only the 200mm concrete floor needs to be raised and poured and hardened during normal excavation.

[0067] It is understandable that the hardened base plate under the special-shaped pier is the key part supporting the entire special-shaped pier and needs to withstand huge vertical and lateral loads.

[0068] According to the preset base plate thickness, the original ground is excavated until it reaches the specified depth. All debris is removed to ensure that the base is flat and clean. After the base is cleaned, a formwork needs to be built to define the boundaries of the concrete pouring. Subsequently, a steel grid is laid in the formwork according to the design specifications to enhance the structural strength and durability of the base plate. The size and spacing of the steel bars must strictly comply with the engineering standards to ensure that the final concrete can reach the expected bearing capacity after hardening. It is necessary to select appropriate grades of concrete and pour it into the formwork in a certain order. With the help of tools such as vibrators, it is fully vibrated to expel bubbles and ensure that the concrete is dense and free of pores. After pouring is completed, it enters the curing period. During this stage, appropriate temperature and humidity conditions need to be maintained to promote the solidification and hardening of the concrete.

[0069] Step S200: Laying out the mold: assembling a rigid mold on the target bottom plate, and laying out a steel skeleton in the rigid mold so that the steel skeleton extends out of the rigid mold, and then assembling a flexible top template on the rigid mold.

[0070] It is understandable that the mold is arranged at a suitable location, usually on a pre-prepared target base plate. The target base plate here should have been hardened and smooth, and be able to bear the subsequent weight. Special rigid mold components, such as steel molds, aluminum molds, etc., are accurately assembled into the required shape and size according to the requirements of the design drawings, and steel bars are placed inside the rigid mold to form a skeleton. Part of the steel skeleton will extend out of the rigid mold and connect to the flexible top template to play an anchoring role and enhance the overall structural connection.

[0071] After the skeleton is laid out in the rigid mold, the flexible top formwork is installed on top of it. The flexible top formwork is usually made of a material with good elasticity, such as aluminum sheet, iron sheet or special plastic, which is convenient for fitting different curved surfaces. The flexible formwork needs to fit the edge of the rigid mold tightly to prevent overflow when pouring concrete.

[0072] It should be noted that in the process of laying out the mold, the center distance between two adjacent rigid molds is 2m to 4m. The center distance of the special-shaped pier column is designed for support strength according to the mining pressure conditions on site, and generally the center distance between two adjacent rigid molds is 3m.

[0073] Step S300: Casting: pouring concrete into the rigid mold and the flexible top formwork.

[0074] It is understandable that in order to simplify the construction, the special-shaped pier column can be cast by using a concrete pump or a mortar pump to pour concrete into the rigid mold and the flexible top template. The pump grout can be C30 concrete and M30 mortar with a strength above, which can be adjusted according to the actual mining pressure on site. The height of the pump injection port from the target bottom plate is 1m to 1.5m, and the general height of the pump injection port from the target bottom plate is 1.2m, which is convenient for personnel operation.

[0075] Step S400: Remove the mold: After determining that the concrete in the rigid mold and the flexible top formwork is completely solidified, in order to reduce costs and facilitate direct cutting of the special-shaped pier column, the rigid mold of the column part is removed. When the working face is advanced to the support position of the special-shaped pier column, the coal mining machine can directly cut it.

[0076] It is understandable that after the concrete is poured, tensile and compression tests are conducted by sampling test blocks to evaluate whether the concrete has reached sufficient strength to independently support its own weight and external loads. Generally speaking, the core area of ​​the structure must reach at least 70% of the design strength before considering demoulding. The flexible top formwork can be removed first, and then the rigid mold can be gradually removed.

[0077] It should be noted that the casting process of special-shaped piers is carried out at a position greater than or equal to 100m away from the lagging excavation working face or after the tunnel excavation is completed.

[0078] Among them, the location where the lagging excavation working face is greater than or equal to 100m, such as pouring the special-shaped pier at 100m, allows the excavation and support processes to be carried out in parallel, does not affect the excavation work, and can be carried out in parallel with the excavation. It can reduce the support strength of the anti-bottom arch, simplify the soft rock excavation support process, and meet the purpose of tunnel surrounding rock control during mining.

[0079] Among them, pouring after the tunnel excavation is completed can ensure the construction safety to the greatest extent, without worrying about the interference of uncertain factors ahead, and the entire pier construction can be carried out in a relatively stable environment. The specific method of pouring is determined based on the results of geological survey, that is, soil properties and hydrological conditions.

[0080] It should be noted that the shape of the special-shaped pier provided in the embodiment of the present invention is compatible with the rigid mold and the flexible top-joining template or the flexible top-joining mold bag, and the special-shaped pier is composed of a steel skeleton and concrete filling materials.

[0081] The tunnel support method based on special-shaped piers in the tunnel provided by the embodiment of the present invention is designed to solve the problems of continuous deterioration of surrounding rock conditions in soft rock tunnels under the action of rheology and creep, especially large deformation of the roof and floor plates under the influence of mining dynamic pressure. It can improve the support strength and support effect of soft rock tunnels, improve the treatment effect and efficiency of deformation of surrounding rock in soft rock tunnels, and reduce the treatment cost. It can fundamentally solve the problem of surrounding rock control under soft rock conditions, avoid the hidden dangers of mining imbalance and overload of personnel caused by the use of the reverse bottom arch method, and the rigid mold of the pier can be reused, which has obvious economic advantages and has the practical significance of reducing costs and increasing efficiency.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A special-shaped pier in a lane, characterized in that: It comprises a cast column and a top support body, wherein the column is arranged along the height direction of the tunnel; the top support body is located above the column and is suitable for contacting the tunnel roof, and the support area of ​​the top support body is larger than the support area of ​​the column; Wherein, the top support body has a top surface, a first curved surface, a second curved surface and a third curved surface, the first curved surface and the second curved surface are symmetrically arranged on both sides of the top surface, the first curved surface and the second curved surface are recessed toward the center of the top support body, the third curved surface is respectively connected to the top surface, the first curved surface and the second curved surface, and the third curved surface protrudes away from the center direction of the top support body.

2. The special-shaped pier in the lane according to claim 1, characterized in that: The top contact support body has a side surface, the side surface is respectively connected to the top contact surface, the first curved surface and the second curved surface, and the side surface is arranged opposite to the third curved surface; The side surface is a plane flush with the vertical direction, or the side surface is an inclined surface extending obliquely upward.

3. The special-shaped pier in the lane according to claim 1, characterized in that: The length of the column is L1, and the length of the top support body is L2, wherein: L2 is greater than or equal to 2 times of L1.

4. The special-shaped pier in the lane according to claim 1, characterized in that: The width of the column is B1, and the width of the top support body is B2, wherein: B2 is greater than B1, and B2 is less than or equal to 2 times of B1.

5. The special-shaped pier in the lane according to claim 1, characterized in that: The height of the column is H1, and the height of the top support body is H2, wherein: H2 is equal to one sixth of H1.

6. The special-shaped pier in the lane according to claim 1, characterized in that: The top edges and bottom edges of the first curved surface and the second curved surface are parallel, the length of the top edges of the first curved surface and the second curved surface is W1, and the length of the bottom edges of the first curved surface and the second curved surface is W2, wherein: W2 is greater than W1, and W2 is less than or equal to 2 times of W1; In the orthographic projection view, the radius R of the third arc surface is equal to half of W2.

7. A tunnel support method based on the special-shaped piers in the tunnel according to any one of claims 1 to 6, characterized in that: The steps include: Hardening the base plate: The floor of the preset thickness is constructed and concrete is poured. The poured concrete hardens to form the target base plate. Laying out the mold: assembling a rigid mold on the target bottom plate, and laying out a steel skeleton in the rigid mold so that the steel skeleton extends out of the rigid mold, and then assembling a flexible top template above the rigid mold; Casting and forming: pouring concrete into the rigid mold and the flexible top template; Removing the mold: After ensuring that the concrete in the rigid mold and the flexible top mold is completely solidified, the rigid mold is removed.

8. The tunnel support method for special-shaped piers in a tunnel according to claim 7, characterized in that: The pouring of concrete into the rigid mold and the flexible top template comprises: A concrete pump or a mortar pump is used to pour H2 concrete into the rigid mold and the flexible top template. The pumped grout can be of a strength higher than C30 concrete and M30 mortar. The height of the pump port from the target bottom plate is 1m to 1.5m.

9. The tunnel support method for special-shaped piers in a tunnel according to claim 7, characterized in that: During the mold layout, the center distance between two adjacent rigid molds is 2m to 4m.

10. The tunnel support method for special-shaped piers in a tunnel according to claim 7, characterized in that: The process of casting and forming special-shaped piers is carried out at a position greater than or equal to 100m from the lagging excavation working face or after the tunnel excavation is completed.

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