Roadway floor support structure and method based on grouting in flexible bags

Abstract

The present invention discloses a roadway floor support structure and method based on grouting in a formwork bag. The support structure includes a plain concrete surface layer, multiple sections of formwork bag grouting support structures, a backfill layer, and an upper steel support arranged successively from bottom to top; control bottom anchor cables are driven into the floor surrounding rock between adjacent formwork bag support structures; the overall formwork bag grouting support structure includes multiple sections of formwork bags arranged side by side, concrete is filled in each section of the formwork bag, triangular locking bodies are fixed at both ends of the formwork bag, the triangular locking bodies are fixed on the surrounding rock at the bottom corners of the roadway through foot-locking anchor cables, and joint devices for connecting with the upper steel support are provided on the triangular locking bodies.

Description

Technical Field

[0001] The invention belongs to the field of underground engineering support, and particularly relates to a roadway floor support structure and method based on bagged grouting. Background Technique

[0002] At present, with the further increase of coal mining depth, most coal mines have entered the deep mining stage. Roadways excavated under complex geological conditions such as deep soft rock and faults are difficult to be stably supported in one time. It is becoming more and more difficult to stably support roadways in one time, and the problem of roadway surrounding rock control is becoming increasingly prominent. Among them, the treatment of roadway floor heave is particularly prominent. Because the floor of the coal mine roadway is not supported or weakly supported, repeated floor excavation will occur, making it a weak link in roadway support, resulting in the release of surrounding rock stress and roadway deformation first appearing on the floor, causing the phenomenon of floor heave, and the floor heave further leads to the overall deformation and damage of the roadway. The existing means of using reinforced concrete bottom beams to control floor heave, the on-site binding of steel bars and pouring of concrete result in slow construction speed and will affect the generation of cracks in the concrete; the means of using prefabricated assembled bottom arc plates to control floor heave, the prefabricated assembled bottom arc plates need to be prefabricated on the ground, and it is not very convenient to transport them from the ground to the deep part of the roadway and is not easy to implement. At present, most mines use repeated floor excavation as the main means to passively deal with floor heave. In this way, it can only provide a short-term solution rather than a fundamental one. Since the floor is the foundation of roadway support, multiple floor excavations will instead accelerate the convergence of the two sides of the roadway and become a booster for roadway damage, hindering the safe and efficient exploitation of deep resources. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a roadway floor support structure and method based on bagged grouting, which can solve the difficult problems of deep roadway support, especially the problem of roadway floor heave.

[0004] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0005] In the first aspect, an embodiment of the present invention provides a roadway floor support structure based on bagged grouting, including a surface layer, multiple sections of bagged support structures, a backfill layer, and a steel support arranged in sequence from bottom to top; control bottom anchor cables are driven deep into the surrounding rock between adjacent bagged support structures; the bagged overall support structure includes multiple sections of bags arranged side by side, concrete is filled in each section of the bag, and triangular locking bodies are fixed at both ends of the bag, and the triangular locking bodies are fixed on the surrounding rock at the bottom corners of the roadway through locking foot anchor cables.

[0006] As a further technical solution, the multiple sections of bags in each section of the bagged support structure are arranged in the longitudinal direction of the roadway.

[0007] As a further technical solution, the triangular locking bodies are arranged in the longitudinal direction of the roadway.

[0008] As a further technical solution, a steel support joint pipe fixing device is installed inside the triangular locking body.

[0009] As a further technical solution, gangue or waste rock is used for backfilling in the backfill layer.

[0010] As a further technical solution, the steel support is a steel support joint pipe concrete support, a U-shaped steel support or an I-beam support.

[0011] Second, the embodiment of the present invention also provides a roadway floor support method based on formwork bag grouting, including the following steps:

[0012] In the first step, the floor rock mass is excavated, and after reaching the design boundary, the floor is cleaned.

[0013] In the second step, concrete is sprayed on the floor to form a concrete surface layer.

[0014] In the third step, a concrete-filled formwork bag is laid on the surface layer, and control bottom anchor cable holes are evenly reserved between the formwork bag groutings. The control bottom anchor cable is drilled into the deep surrounding rock through these holes, which can improve the overall stability of the floor.

[0015] In the fourth step, multiple sections of formwork bags are laid at a certain distance along the longitudinal direction of the roadway, and then concrete is filled into the formwork bags to form formwork bag groutings. Triangular locking bodies are arranged at both ends of each section of formwork bag respectively, and anchor cable holes are evenly reserved in each triangular locking body. The foot-locking anchor cables are drilled into the deep surrounding rock through these holes, so that the formwork bag groutings cooperate with the foot-locking anchor cables of the triangular locking bodies to form a whole.

[0016] In the fifth step, finally, gangue or waste rock is used to backfill the floor.

[0017] In the sixth step, the support is installed.

[0018] Beneficial effects brought by the technical solution of the present invention:

[0019] 1. In the composite support scheme of formwork bag grouting, steel support, triangular locking body, foot-locking anchor cable and control bottom anchor cable, the floor is strengthened by formwork bag grouting + steel support + triangular locking body + foot-locking anchor cable + control bottom anchor cable, which improves the floor support force under conventional support conditions and effectively inhibits the floor heave deformation.

[0020] 2. The shape, thickness and length of the formwork bag are designed according to the support force of the roadway floor and the actual situation. The formwork bag is convenient for processing, construction and installation, which greatly saves the labor cost.

[0021] 3. The anchoring end of the control bottom anchor cable must be below the zero displacement marking line of the floor. The purpose of extending into the zero displacement marking line is to: stabilize the anchoring force and prevent the anchoring end from possibly rising with the floor uplift, resulting in the anchor cable being unable to exert the anchoring effect.

[0022] 4. The design of using triangular locking bodies and locking-foot anchor cables at the bottom corners is to fix the formwork bag grouting. A steel support joint pipe is used to strengthen the support structure inside the triangular locking bodies. Anchor cable holes are evenly reserved on each triangular locking body. The locking-foot anchor cables are drilled into the deep surrounding rock through these holes to provide an upward reaction force against the floor heave force, inhibit the lifting of the formwork bag grouting, enhance the integrity, improve the bearing capacity, and prevent the floor heave from damaging the entire roadway. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments and descriptions thereof of the invention are used to explain the invention and do not constitute an improper limitation to the invention.

[0024] Figure 1 is the plan view of the formwork bag grouting support structure proposed in the embodiment of the present invention;

[0025] Figure 2 is the schematic diagram of the single-section formwork bag grouting support structure proposed in the embodiment of the present invention;

[0026] Figure 3 is the schematic diagram of the overall formwork bag grouting support structure proposed in the embodiment of the present invention;

[0027] Figure 4 is the schematic diagram of the triangular locking body support structure proposed in the embodiment of the present invention;

[0028] Figure 5 is the schematic diagram of the single-roll formwork bag grouting support structure proposed in the embodiment of the present invention;

[0029] In the figures: The distances or dimensions between each part are exaggerated for showing the positions of each part, and the schematic diagrams are only for illustration purposes.

[0030] 1 - steel support, 2 - formwork bag grouting, 3 - grouting port, 4 - fiber bundle, 5 - concrete surface layer, 6 - triangular locking body, 7 - locking-foot anchor cable, 8 - gangue or waste rock, 9 - floor control anchor cable, 10 - zero-displacement marking line, 11 - steel support joint pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present invention. As used herein, unless the present invention clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof;

[0033] For the convenience of description, if the words "upper", "lower", "left", and "right" appear in the present invention, they only indicate the same directions as the upper, lower, left, and right of the attached drawings themselves, and do not limit the structure. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0034] Glossary: In this embodiment, the "bottom control cable anchor" refers to a common cable anchor for realizing bottom control; the "foot-locking cable anchor" is a common cable anchor for fixing the triangular locking body.

[0035] As introduced in the background art, there are deficiencies in the prior art. To solve the above technical problems, the present invention proposes a roadway floor support structure and method based on formwork bag grouting.

[0036] In a typical embodiment of the present invention, the roadway floor support structure based on formwork bag grouting includes a composite structure form such as formwork bag grouting, steel support, triangular locking body, foot-locking cable anchor, bottom control cable anchor, etc. These structures are combined together to form a Figure 1 , Figure 2 (single-section support structure) and Figure 3 (overall support structure) as shown in the roadway floor support structure of formwork bag grouting.

[0037] The following describes the detailed structure of the roadway floor support of formwork bag grouting:

[0038] (1) Overall structure

[0039] As Figure 1As shown in the figure, the overall support structure is composed of structures such as steel support 1, bagged grouting 2, triangular locking body 6, foot-locking anchor cable 7, and floor-control anchor cable 9. Among them, the single-section bagged grouting support structure includes multiple sections of bagged grouting arranged side by side. Each bagged grouting is filled with concrete. At both ends of the bagged grouting, a triangular locking body 6 is horizontally installed respectively. The triangular locking body 6 cooperates with the foot-locking anchor cable 7 to fix the bagged grouting. In the triangular locking body 6, a steel support joint pipe 11 is used to strengthen the support structure. Three anchor cable holes are evenly reserved on the triangular locking body 6. The foot-locking anchor cable 7 is drilled into the deep surrounding rock through this hole; the two sides and the roof are supported by the steel support 1 structure, and the steel support 1 just presses on the triangular locking body 6. In this way, the steel support 1, the bagged grouting 2, and the triangular locking body 6 cooperate with the foot-locking anchor cable 7 to form an overall structure with full-circumference support, enhancing the overall support force and effectively suppressing floor heave.

[0040] After the excavation of the bottom arch of the roadway, a concrete surface layer 5 is sprayed on the roadway floor. Five floor-control anchor cable holes are evenly reserved between the bagged groutings. The floor-control anchor cable 9 is drilled into the deep surrounding rock through this hole. The anchoring end of the floor-control anchor cable 9 exceeds the depth of the zero-displacement marking line 10 to prevent the anchoring end from possibly rising as the floor rises, resulting in the anchor cable being unable to exert its anchoring effect, enhancing the overall stability of the structure and improving the overall support force of the structure.

[0041] The single-section bagged grouting support structure is as Figure 1 and Figure 2 shown. The overall composite support structure is as Figure 3 shown.

[0042] (2)Bagged grouting support materials

[0043] The bagged grouting support structure is composed of multiple rolls of flexible bagged grouting. Fiber bundles are used for connection at intervals in the middle. Concrete is filled in the bagged grouting to form bagged grouting, which can improve the overall strength of the bagged grouting. The bagged grouting support materials have the following characteristics: they are formed by grouting, with simple construction and high speed; they can adapt to various complex terrains, with high mechanization degree, large support area, strong integrity, good stability, and long service life; they have certain water permeability. After the concrete is poured in, the excess water seeps out through the fabric voids, which can quickly reduce the water-cement ratio, accelerate the setting speed of the concrete, and increase the compressive strength of the concrete; these characteristics of the bagged grouting support materials can provide strong support force and effectively suppress the deformation of floor heave.

[0044] Bottom corner treatment method: The bottom corner uses the triangular locking body 6 in cooperation with the foot-locking anchor cable 7 (as Figure 5The governance method shown in the figure is adopted. The triangular locking body 6 is used in cooperation with the foot-locking anchor cable 7 to press the bottom corner of the formwork bag grouting. The steel support joint pipe 11 is used to strengthen the support structure inside the triangular locking body 6. One triangular locking body 6 is installed on each side of the bottom corner of each section of the formwork bag grouting. Three cable holes are evenly reserved on each triangular locking body. The foot-locking anchor cable 7 is drilled into the surrounding rock through this hole. The function of the triangular locking body 6 in cooperation with the foot-locking anchor cable 7 is to form a whole with the formwork bag grouting 2 and play a restraining role on the formwork bag grouting 2, preventing the formwork bag grouting 2 from protruding upward under the action of the floor heave force and providing a reaction support force; the formwork bag grouting 2 and the triangular locking body 6 in cooperation with the foot-locking anchor cable 7 can form a whole to better provide support force and make the structure more stable.

[0045] The construction technology of the composite support structure proposed in this embodiment

[0046] The roadway floor support method based on formwork bag grouting has the following overall construction process:

[0047] The first step is to mechanically excavate the floor rock mass, and after excavating to the design boundary, clean the floor.

[0048] The second step is to spray concrete on the floor to form a concrete surface layer 5.

[0049] The third step is to lay a concrete-filled formwork bag on the surface layer, and evenly reserve 5 bottom-control anchor cable holes between the formwork bag groutings. The bottom-control anchor cable 10 is drilled into the deep surrounding rock through this hole, which can improve the overall stability of the floor.

[0050] The fourth step is to lay multiple sections of formwork bags at a certain distance along the longitudinal direction of the roadway. Triangular locking bodies 6 are respectively arranged at the bottom corners of multiple sections of formwork bags. Three foot-locking anchor cables are installed in the evenly reserved cable holes on each triangular locking body. Then, concrete is filled into the formwork bags to form formwork bag grouting 2, so that the formwork bag grouting 2 and the triangular locking body 6 in cooperation with the foot-locking anchor cable 7 form a whole.

[0051] The fifth step is to finally backfill the floor with gangue or waste rock.

[0052] The sixth step is to install the support.

[0053] Completing the above steps in sequence along the longitudinal direction of the chamber can complete this support scheme.

[0054] The main parameters that need to be determined according to different conditions such as the roadway burial depth, geological conditions, ground stress, and lithology, as well as the actual on-site situation for the device proposed in this embodiment are: the thickness, length, strength, and curvature of the formwork bag grouting, and the types and row and column spacings of the anchor cables and foot-locking anchor cables. These parameters are designed according to the actual situation.

[0055] A new method for floor treatment based on grouting in geotextile bags proposed by the present invention mainly consists of the following two parts. The first part is the bottom arch of the method, which mainly includes grouting in geotextile bags, triangular locking bodies, foot-locking anchor cables and floor-control anchor cables. The foot-locking anchor cables are connected to the triangular locking bodies to form an integral whole, increasing the reaction force acting upward on the surrounding rock. Five floor-control anchor cables are evenly installed in the grouting in geotextile bags. The second part is the steel support, which just presses on the triangular locking bodies. These two parts form a full-circumference support structure to strengthen the support force of the floor, effectively inhibiting the occurrence of floor heave and improving the safety of the roadway.

[0056] First, the floor is excavated. After the excavation and slag cleaning, shotcrete is sprayed to form a surface layer. Multiple sections of grouting in geotextile bags are laid at certain intervals along the longitudinal direction of the roadway. Five anchor cable holes are evenly reserved between the grouting in geotextile bags. The floor-control anchor cables are drilled into the surrounding rock through these holes, and the anchoring ends of the anchor cables exceed the depth of the zero-displacement marking line of the floor, where the depth of the zero-displacement marking line is determined through on-site monitoring and in combination with theoretical analysis.

[0057] The grouting in geotextile bag support structure proposed by the present invention is composed of multiple rolls of flexible geotextile bags, which are connected by fiber bundles at intervals in the middle. Concrete is poured into the geotextile bags to form grouting in geotextile bags, which can improve the overall strength of the geotextile bags. The grouting in geotextile bag support material has the following characteristics: it is formed by grouting, with simple construction and high speed; it can adapt to various complex terrains, with high mechanization level, large support area, strong integrity, good stability and long service life; it has a certain water permeability. After the concrete is poured in, the excess water seeps out through the fabric voids, which can quickly reduce the water-cement ratio, accelerate the setting speed of the concrete and increase the compressive strength of the concrete; these characteristics of the grouting in geotextile bag support material can provide strong support force and effectively inhibit the deformation of floor heave.

[0058] In the present invention, the bottom corners adopt the treatment method of combining triangular locking bodies with foot-locking anchor cables. The triangular locking bodies are combined with the foot-locking anchor cables to fix the grouting in geotextile bags. Steel support joint pipes are used to strengthen the support structure inside the triangular locking bodies. One triangular locking body is installed on each side of the bottom corners of the grouting in geotextile bags. Three anchor cable holes are evenly reserved on each triangular locking body. The foot-locking anchor cables are drilled into the surrounding rock through these holes. The function of the triangular locking bodies combined with the foot-locking anchor cables is to form an integral whole with the grouting in geotextile bags, providing a reaction support force to prevent the grouting in geotextile bags from bulging upward under the action of the floor heave force; the combination of the grouting in geotextile bags, the triangular locking bodies and the foot-locking anchor cables can better provide support force and make the structure more stable.

[0059] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. The roadway floor support structure based on the grouting of the formwork bag is characterized in that It includes a plain concrete surface layer, multiple-section mold bag support structures, a backfill layer, and an upper steel support arranged successively from bottom to top; the surface layer is formed by spraying concrete on the excavated bottom plate; each section of the mold bag support structure includes multiple mold bags arranged side by side, and concrete is filled in each mold bag to form a grouted mold bag. Control bottom anchor cables are driven into the surrounding rock of the bottom plate between adjacent mold bags. The anchoring end of the control bottom anchor cable is fixed below the zero displacement marking line of the bottom plate to prevent the anchoring end from rising with the uplift of the bottom plate; triangular locking bodies are fixed at both ends of each section of the mold bag support structure, and locking foot anchor cable holes are uniformly reserved on each triangular locking body. The locking foot anchor cables are driven deep into the surrounding rock through these holes, and the triangular locking bodies are fixed on the surrounding rock at the bottom corners of the roadway through the locking foot anchor cables; a steel support joint pipe for connecting with the upper steel support is provided on the triangular locking body, and the support structure is strengthened through the steel support joint pipe; the steel support, the grouted mold bag, and the triangular locking body cooperate with the locking foot anchor cables to form an overall structure for full-circumference support; the multiple-section mold bag support structures are arranged in the longitudinal direction of the roadway and fully cover the bottom plate; the triangular locking bodies are arranged in the longitudinal direction of the roadway; the backfill layer is backfilled with waste gangue after roadway excavation.

2. The roadway floor support structure based on the grouting of the formwork bag as claimed in claim 1, wherein, The shape, thickness, and length of the mold bag are designed according to the support force required for the roadway bottom plate.

3. The roadway floor support structure based on the bag grouting as claimed in claim 1, characterized in that, The steel support is one of a concrete-filled steel tube support, a U-shaped steel support, or an I-beam support.

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