Externally attached fiber layer and preparation method, underground structure and assembled construction method

Abstract

The present invention discloses an externally attached fiber layer, a preparation method, and an assembly construction method, and belongs to the technical field of urban underground space. The externally attached fiber layer includes: a fiber fixing plate, a frame is connected below the fiber fixing plate, a plurality of fiber fixing wires parallel to each other are arranged on the frame, the fiber fixing wires are parallel to the fiber fixing plate, and are separated from the fiber fixing plate by a set distance; steel fibers are connected between the fiber fixing plate and the fiber fixing wires. During assembly construction, the externally attached fiber layer is fixed to the bottom surface of the prefabricated component, and the prefabricated component is installed on a fine-leveling strip, so that the length direction of the fiber fixing wires in the externally attached fiber layer is parallel to the length direction of the fine-leveling strip; non-shrinkage cement is poured along the length direction of the fiber fixing wires to form a grouting layer. Since the position of the steel fiber is fixed by the fiber fixing wires and the fiber fixing plate, and the flow direction of the fiber fixing wires is consistent with that of the casting material, the casting material can flow fully, and a casting layer with uniform distribution of steel fibers can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of urban underground space, and in particular to an externally-attached fiber layer and a preparation method thereof, an underground structure and an assembled construction method. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] When the underground project adopts the prefabricated construction method, the foundation pit is first constructed, and then the cushion layer is constructed on the foundation pit. Then, a fine-leveling strip with a set elevation is constructed on the cushion layer, and then the prefabricated main structure is assembled on the fine-leveling strip. At this time, there is a gap between the main structure and the cushion layer, which needs to be filled with grouting, and the grouting material after solidification forms a grouting layer. The grouting layer combines the main structure and the cushion layer into an integral force-bearing system. Due to the low height of the gap between the main structure and the cushion layer, the construction quality during the grouting construction is difficult to control, so the strength of the grouting layer is much lower than that of the main structure and the cushion layer. In the subsequent operation of the underground engineering structure, the grouting layer is prone to performance degradation under the vibration of the train and the scouring of groundwater, resulting in the main structure and the cushion layer being emptied, causing a series of problems such as structural settlement and damage.

[0004] Improving the strength and durability of the grouting layer is particularly important for the quality of underground projects. In the existing technology, adding fibers can effectively improve the strength and durability of concrete, but due to the extremely narrow gap between the main structure and the cushion layer, directly adding fibers during grouting can easily lead to blockage of the grouting pipe; when adding fibers by external mixing, the fibers are easily unevenly distributed under the scouring of the slurry, and the effect of improving the overall durability of the grouting layer is limited. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an external fiber layer and a preparation method, an underground structure and an assembled construction method, wherein the external fiber layer is prefabricated and includes reinforcing fibers and does not affect the fluidity of the grouting material. During construction, the external fiber layer is placed in advance in the gap between the main structure and the cushion layer, and then grouting is performed, which can ensure that the reinforcing fibers are evenly distributed in the grouting layer, thereby improving the performance of the grouting layer.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] The first aspect of the present invention provides an external fiber layer, comprising: a fiber fixing plate, a frame connected to the bottom of the fiber fixing plate, a plurality of fiber fixing wires parallel to each other are arranged on the frame, the fiber fixing wires are parallel to the fiber fixing plate and are separated from the fiber fixing plate by a set distance; steel fibers are connected between the fiber fixing plate and the fiber fixing wires.

[0008] Optionally, the diameter of the steel fiber is 0.10-0.20 cm.

[0009] Optionally, the height of the outer fiber layer is equal to the gap between the main structure and the cushion layer, and the width of the outer fiber layer is equal to the spacing between adjacent fine-leveling strips.

[0010] Optionally, the interval between adjacent fiber fixing wires is 8 to 10 cm, the steel fibers are distributed along the length direction of the fiber fixing wires, and the interval between adjacent steel fibers is 2 to 5 cm.

[0011] Optionally, the skeleton includes four intermediate skeletons connected to the four corners of the fiber fixing plate and a bottom skeleton forming a frame structure below the intermediate skeletons. The intermediate skeletons are perpendicular to the fiber fixing plate, the frame structure is parallel to the fiber fixing plate, and both ends of the fiber fixing wire are fixed on the bottom skeleton.

[0012] Optionally, the fiber fixing plate is a steel plate, an epoxy resin plate or a fiber reinforced nylon plate.

[0013] Optionally, the intermediate skeleton is made of flexible steel bars or fiber-reinforced composite material bars.

[0014] Optionally, the bottom skeleton is made of iron wire or basalt fiber reinforcement.

[0015] Optionally, the fiber fixing wire is made of iron wire or basalt fiber reinforcement.

[0016] Optionally, the steel fiber is a straight steel fiber, and both ends of the steel fiber are respectively fixed on a fiber fixing plate and a fiber fixing wire, and a connecting line formed by both ends of a single steel fiber is perpendicular to the fiber fixing plate.

[0017] Optionally, the distribution density of the steel fibers along the length direction of the fiber fixing wire is greater than the distribution density in the direction perpendicular to the length direction of the fiber fixing wire.

[0018] Optionally, a fixing ring is provided on the skeleton.

[0019] Optionally, the fixing ring is arranged on the middle frame.

[0020] The second aspect of the present invention provides a method for preparing the above-mentioned external fiber layer, comprising the steps of:

[0021] The fiber fixing plate is connected to the frame, and then the fiber fixing wires parallel to each other are installed on the frame, and the fiber fixing wires are separated from the fiber fixing plate by a set distance;

[0022] One end of the steel fiber is fixed on the fiber fixing plate, and the other end of the steel fiber is fixed on the fiber fixing wire, and the steel fiber is perpendicular to the fiber fixing plate.

[0023] Optionally, the steel fibers are connected to the fiber fixing plate by bonding.

[0024] Optionally, the steel fibers are connected to the fiber fixing plate by bonding.

[0025] Optionally, an intermediate frame is vertically installed at the four corners of the fiber fixing plate, and then the bottom frame is tied with one end of the intermediate frame away from the fiber fixing plate as the frame end point.

[0026] Optionally, the intermediate frame is connected to the fiber fixing plate by bonding.

[0027] The third aspect of the present invention provides an underground structure, including a grouting layer located between a prefabricated component and a cushion layer, wherein the grouting layer is provided with the above-mentioned external fiber layer, and the fiber fixing plate of the external fiber layer is connected to the bottom surface of the prefabricated component, and the fiber fixing wire is attached to the upper surface of the cushion layer.

[0028] A fourth aspect of the present invention provides an assembled construction method for an underground structure, comprising the following steps:

[0029] S1, fixing the above-mentioned external fiber layer on the bottom surface of the prefabricated component, and installing the prefabricated component on the fine flat strip, so that the length direction of the fiber fixing wire in the external fiber layer is parallel to the length direction of the fine flat strip;

[0030] S2. Rubber strips are arranged on both sides of the outer fiber layer to seal the gap between the fine flattening strip and the outer fiber layer;

[0031] S3. Pour non-shrinkage cement along the length direction of the fiber fixing wire to form a grouting layer.

[0032] Optionally, in S2, the frame is fixed on the cushion layer using a fixing ring.

[0033] The beneficial effects of the present invention are as follows:

[0034] The present invention prefabricates an external fiber layer in an underground project of prefabricated construction, and the external fiber layer is provided with steel fibers at fixed positions, which can be combined with the casting material to form a casting layer in the subsequent casting process. Since the position of the steel fibers in the external fiber layer is fixed by the fiber fixing wire and the fiber fixing plate, the casting process will not change the distribution state of the steel fibers. In the casting layer finally obtained, the steel fibers can maintain a vertical state in the same direction as the bearing capacity of the casting layer, which can greatly improve the strength and durability of the casting layer. On the other hand, the distribution density of the steel fibers along the length direction of the fiber fixing wire is greater, and the flow direction of the fiber fixing wire is consistent with that of the casting material, which can avoid the steel fibers from forming resistance to the flow of the casting material, can ensure the full flow of the casting material, improve the quality of the casting layer, and thus improve the quality of the underground project. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] In order to show the positions of various parts, the distances or sizes between them are exaggerated in the figure, and the schematic diagram is for illustration only.

[0037] Figure 1 It is a schematic diagram of the structure of the external fiber layer in Example 1.

[0038] Figure 2 It is a schematic diagram of the application method of the external fiber layer in Example 2.

[0039] Figure 3 It is a structural schematic diagram of the underground project before grouting in Example 2.

[0040] Figure 4 It is a structural schematic diagram of the underground project after grouting in Example 2.

[0041] Among them, 1. External fiber layer; 2. Fiber fixing plate; 3. Middle frame; 4. Bottom frame; 5. Fiber fixing wire; 6. Fixing ring; 7. Steel fiber; 8. Fine flat strip; 9. Cushion layer; 10. "L"-shaped side wall block; 11. "I"-shaped bottom plate; 13. Finely rolled threaded steel bar; 14. Grouting layer; 15. Steel nails; 16. Tensioning gap; 17. Rubber strip. DETAILED DESCRIPTION

[0042] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] Example 1

[0045] An external fiber layer 1, such as Figure 1 As shown, it includes: a fiber fixing plate 2, a frame is connected below the fiber fixing plate 2, a plurality of fiber fixing wires 5 parallel to each other are arranged on the frame, the fiber fixing wires 5 are parallel to the fiber fixing plate 2, and are separated from the fiber fixing plate 2 by a set distance; a plurality of steel fibers 7 are connected between the fiber fixing plate 2 and the fiber fixing wires 5.

[0046] The diameter of the steel fiber 7 is 0.15 cm.

[0047] The distribution density of the fiber fixing wire 5 is 9±1 cm, and the steel fibers 7 are distributed along the length direction of the fiber fixing wire 5. The distribution density of the steel fibers 7 in the length direction of the fiber fixing wire 5 is 2±0.5 cm.

[0048] Through the above arrangement, the steel fibers 7 used to reinforce the casting layer are fixed in the outer fiber layer 1, which can avoid changing the distribution mode of the steel fibers 7 during the casting process, and form a casting layer with uniform distribution of the steel fibers 7; and the distribution density of the steel fibers 7 along the length direction of the fiber fixing wire 5 is greater than the distribution density perpendicular to the length direction of the fiber fixing wire 5, which can avoid obstruction to the flow of the casting material and improve the quality of the casting layer.

[0049] The frame includes four intermediate frames 3 connected to the four corners of the fiber fixing plate and a bottom frame 4 forming a frame structure below the intermediate frames 3. The intermediate frames 3 are perpendicular to the fiber fixing plate 2, the frame structure is parallel to the fiber fixing plate 2, and both ends of the fiber fixing wire 5 are fixed on the bottom frame 4.

[0050] The height of the external fiber layer 1 is equal to the gap between the main structure and the cushion layer, and the width of the external fiber layer 1 is equal to the spacing between adjacent fine-leveling strips; by prefabricating an external fiber layer of a set size, a casting layer with uniformly distributed steel fibers can be formed in the space surrounded by the main structure, the cushion layer and the fine-leveling strips, thereby improving the bearing capacity of the casting layer.

[0051] The middle frame 3 is made of flexible steel bars and has a certain deformation capacity. It can deform as the size of the gap between the main structure and the cushion layer changes, which is beneficial to ensure that the outer fiber layer 1 is flush with the precision leveling strip.

[0052] The bottom frame 4 is made of iron wire, and the fiber fixing wire 5 is made of iron wire, so that the lower surface of the frame has elasticity and can fit with the upper surface of the cushion layer.

[0053] The steel fiber 7 can be selected as a linear steel fiber, and the two ends of the steel fiber 7 are respectively fixed on the fiber fixing plate 2 and the fiber fixing wire 5, and the single steel fiber 7 is perpendicular to the fiber fixing plate 2, so that the distribution of the steel fiber 7 has orientation, which is perpendicular to the bottom surface of the prefabricated structure. The orientation is consistent with the bearing force direction of the casting layer, so that the vertical force transmitted from the upper load can be borne to a greater extent, the compressive and bearing capacity can be improved, and the performance of the casting layer can be greatly improved.

[0054] A fixing ring 6 is provided on the frame, and a steel nail can be used to pass through the fixing ring 6 to fix the outer fiber layer 1 on the cushion layer to avoid the overall movement of the outer fiber layer 1 during the pouring process.

[0055] The preparation method of the external fiber layer 1 in this embodiment includes:

[0056] Use epoxy resin glue to vertically bond the middle frame 3 at the four corners of the fiber fixing plate 2, then use the end of the middle frame 3 away from the fiber fixing plate 2 as the frame end point, tie the bottom frame 4, and fix the tying point by welding to obtain an overall structure where the fiber fixing plate and the frame are connected together.

[0057] The fiber fixing wires 5 are parallel to each other and installed on the bottom frame 4. The distance between the fiber fixing wires 5 and the fiber fixing plate 2 is equal to the height of the middle frame 3. The fiber fixing wires 5 are iron wires, and the fiber fixing wires 5 and the bottom frame 4 are fixed together by welding.

[0058] One end of the steel fiber 7 is fixed on the fiber fixing plate 2 using steel glue, and the other end of the steel fiber 7 is fixed on the fiber fixing wire 5 using steel glue. After the fixing is completed, the steel fiber 7 is perpendicular to the fiber fixing plate 2.

[0059] A fixing ring 6 is arranged on the middle frame 3 to obtain a finished product with an externally applied fiber layer 1 .

[0060] Example 2

[0061] U-shaped trough structure is a common structure in underground engineering, such as Figure 3 As shown, the prefabricated component of the U-shaped channel includes an “I”-shaped bottom plate 11 and “L”-shaped side wall blocks 10 arranged on both sides of the “I”-shaped bottom plate 11.

[0062] The assembled construction method of the underground project using the external fiber layer 1 in Example 1 comprises the following steps:

[0063] The construction steps before applying the external fiber layer 1 include:

[0064] The cushion layer is constructed based on the principle of "quick excavation and quick construction of concrete cushion layer". The exposure time of the soil at the bottom of the foundation pit is controlled. The structural plain concrete cushion layer uses C20 concrete and is constructed in sections. After final setting, it is covered and maintained in time to prevent cracking of the cushion layer concrete. After the base soil is cleaned, if it rains, cover the bottom of the pit with plastic film.

[0065] like Figure 3 As shown, a leveling layer is set above the cast-in-place bottom plate, and a groove of the grouting pipe is formed at the bottom to form a cushion layer 9, and a fine-leveling strip 8 is arranged longitudinally on the top. The fine-leveling strip 8 is constructed in blocks, sections, and batches. The fine-leveling strip 8 is constructed first, using a specific strip material, and a fiber-reinforced aluminum-based composite material. The elevation of the fine-leveling strip 8 is controlled by embedded angle steel, and the precision of the fine-leveling strip is controlled within ±2mm to ensure that the upper components (including the "I"-shaped bottom plate 11 and the "L"-shaped side wall block 10) are longitudinally linearly controllable. There are gaps between the fine-leveling strips 8 to prepare for subsequent grouting.

[0066] When the external fiber layer in Example 1 is used for application, the steps include:

[0067] S1, such as Figure 2 As shown, the outer fiber layer 1 is fixed to the bottom surface of the prefabricated component (including the "L"-shaped side wall block 10), and the "L"-shaped side wall block 10 is installed on the fine flat strip 8, so that the length direction of the fiber fixing wire 5 in the outer fiber layer 1 is parallel to the length direction of the fine flat strip 8; because the skeleton of the outer fiber layer 1 has a certain deformation ability, and the length of the middle skeleton 3 is determined according to the gap thickness between the "L"-shaped side wall block 10 and the cushion layer 9, it can be ensured that the outer fiber layer 1 is flush with the fine flat strip 8; when assembling the prefabricated components, as shown in FIG. Figure 3 As shown, after the "L"-shaped side wall block 10 is aligned with the "I"-shaped bottom block 11, the fine-rolled threaded steel bar 13 is inserted into the reserved tensioning hole of the side wall block. In order to ensure that the external fiber layer 1 is not damaged during the tensioning process, the external fiber layer is pasted in sections (the fiber layer is pre-made to a certain size and is directly pasted to the bottom of the prefabricated part of the U-shaped groove). A tensioning gap 16 is reserved between adjacent prefabricated components (for example, the "I"-shaped bottom block 11 and the "L"-shaped side wall blocks 10 on both sides). The external fiber layer 1 is no longer pasted in the tensioning gap 16 above the cushion layer 9, because the external fiber layer 1 pasted in the tensioning gap 16 position is easily damaged during assembly, affecting the effect, so the tensioning gap 16 position is only grouted at the end.

[0068] S2, such as Figure 2As shown, the fixing ring 6 is nailed to the cushion layer 9 by steel nails 15 to fix the position of the outer fiber layer 1; in order to prevent the slurry from seeping out during the grouting process, a structure to prevent the slurry from seeping out is required, and the gaps at the four corners of the outer fiber layer 1 are sealed with rubber strips 17 to prevent the slurry from seeping out from the four sides during the grouting process, and a middle pore is left at the sealed position, and a grouting pipe is placed at the middle pore;

[0069] S3, such as Figure 4 As shown, non-shrinkage cement is poured along the length direction of the fiber fixing wire 5 to form a grouting layer 14. The flow resistance of the grouting material in this direction is the lowest, which prevents the slurry from knocking down the steel fibers and the steel bar skeleton during the grouting process and ensures the stability of the fiber layer.

[0070] The tensioning gap 16 is only filled with non-shrinkage cement. Since the tensioning gap is small, it does not affect the supporting effect of the external fiber layer 1 at other positions.

[0071] Since the length of the middle skeleton 3 is determined according to the gap thickness between the "L"-shaped side wall block 10 and the cushion layer 9, the middle skeleton 3 can support the fiber fixing wire downward to the surface of the cushion layer 9, and the fiber fixing wire has elasticity. When the surface of the cushion layer 9 is not flat enough, the fiber fixing wire can properly fit the surface of the cushion layer 9, so that the steel fiber 7 can effectively strengthen the connection between the grouting layer 14 and the upper and lower structures ("L"-shaped side wall block 10, "I"-shaped bottom plate 11 and cushion layer 9).

[0072] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An external fiber layer for underground engineering, characterized in that: include: A fiber fixing plate, wherein a frame is connected below the fiber fixing plate, and a plurality of fiber fixing wires parallel to each other are arranged on the frame. The fiber fixing wires are parallel to the fiber fixing plate and are separated from the fiber fixing plate by a set distance; steel fibers are connected between the fiber fixing plate and the fiber fixing wires; The steel fiber is a straight steel fiber, and the two ends of the steel fiber are respectively fixed on the fiber fixing plate and the fiber fixing wire, and the connecting line formed by the two ends of a single steel fiber is perpendicular to the fiber fixing plate; The distribution density of the steel fibers along the length direction of the fiber fixing wire is greater than the distribution density perpendicular to the length direction of the fiber fixing wire; The frame includes four middle frames connected to the four corners of the fiber fixing plate and a bottom frame forming a frame structure below the middle frames. The middle frames are perpendicular to the fiber fixing plate, the frame structure is parallel to the fiber fixing plate, and the two ends of the fiber fixing wire are fixed on the bottom frame.

2. The external fiber layer for underground engineering according to claim 1, characterized in that: The diameter of the steel fiber is 0.10-0.20 cm; The steel fibers are distributed along the length direction of the fiber fixing wire, and the distance between adjacent steel fibers is 2-5 cm; The height of the outer fiber layer is equal to the gap between the main structure and the cushion layer, and the width of the outer fiber layer is equal to the spacing between adjacent fine-leveling strips.

3. The external fiber layer for underground engineering according to claim 1, characterized in that: The interval between adjacent fiber fixing wires is 8~10cm.

4. The external fiber layer for underground engineering according to claim 1, characterized in that: The fiber fixing plate is a steel plate, an epoxy resin plate or a fiber reinforced nylon plate; The intermediate frame is made of flexible steel bars or fiber-reinforced composite material bars; The bottom frame is made of iron wire or basalt fiber reinforcement; The fiber fixing wire is made of iron wire or basalt fiber reinforcement.

5. The external fiber layer for underground engineering according to claim 1, characterized in that: The frame is provided with a fixing ring; the fixing ring is provided on the middle frame.

6. A method for preparing an external fiber layer for underground engineering according to claim 1, characterized in that: Includes steps: The fiber fixing plate is connected to the frame, and then the fiber fixing wires parallel to each other are installed on the frame, and the fiber fixing wires are separated from the fiber fixing plate by a set distance; One end of the steel fiber is fixed on the fiber fixing plate, and the other end of the steel fiber is fixed on the fiber fixing wire, and the steel fiber is perpendicular to the fiber fixing plate.

7. The method for preparing an external fiber layer for underground engineering according to claim 6, characterized in that: The steel fibers are connected to the fiber fixing plate by bonding; The steel fibers are connected to the fiber fixing plate by bonding; The middle frame is vertically installed at the four corners of the fiber fixing plate, and then the end of the middle frame away from the fiber fixing plate is used as the frame end point to tie the bottom frame; The intermediate frame is connected to the fiber fixing plate in a bonding manner.

8. An underground structure comprising a grouting layer between a prefabricated component and a cushion layer, characterized in that: The grouting layer is provided with an external fiber layer for underground engineering as described in any one of claims 1-5, and the fiber fixing plate of the external fiber layer is connected to the bottom surface of the prefabricated component, and the fiber fixing wire is attached to the upper surface of the cushion layer.

9. An assembled construction method for an underground structure using the external fiber layer for underground engineering as claimed in any one of claims 1 to 5, characterized in that: The process includes: S1, fixing the outer fiber layer on the bottom surface of the prefabricated component, installing the prefabricated component on the fine flat strip, so that the length direction of the fiber fixing wire in the outer fiber layer is parallel to the length direction of the fine flat strip; S2. Rubber strips are arranged on both sides of the outer fiber layer to seal the gap between the fine flattening strip and the outer fiber layer; S3, pouring non-shrinkage cement along the length direction of the fiber fixing wire to form a grouting layer; Optionally, in S2, the frame is fixed on the cushion layer using a fixing ring.

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