Double-layer corrugated plate support structure for controlling tunnel arch foot convergence and construction method thereof

Abstract

The application discloses a double-layer corrugated plate supporting structure for controlling convergence of a tunnel arch foot and a construction method thereof, and the supporting structure comprises a first layer of corrugated plates, a second layer of corrugated plates, supporting rods, fences, anchor rods, supporting rods and cement piers; the second layer of corrugated plates is arranged on one side of the front surface of the first layer of corrugated plates, a groove-shaped space is formed between the two layers, the two layers are connected and fixed through the supporting rods, and the groove-shaped space is filled with high-molecular polymers; a column of grouting holes and two columns of anchor rod holes located on the two sides of the grouting holes are arranged on the first layer of corrugated plates; the anchor rods are punched into the rock stratum on the back surface of the first layer of corrugated plates through the anchor rod holes; the upper end of the supporting rod is connected with the front surface of the second layer of corrugated plates, and the lower end of the supporting rod is provided with a cast-in-place cement pier. In the supporting of the high ground stress tunnel, the deformation energy of the surrounding rock can be absorbed, the stress of the surrounding rock can be released, the self-bearing function of the surrounding rock can be played, meanwhile, the convergence deformation of the arch foot can be well controlled, the generation of large deformation can be avoided, and the upper step and the middle step are more stable in the excavation process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a double-layer corrugated plate supporting structure for controlling convergence of tunnel arch foot and a construction method thereof. BACKGROUND

[0002] When a tunnel is constructed in high-stress soft surrounding rock, large deformation problems frequently occur in the tunnel construction process due to high stress and other problems, especially the convergence deformation of the arch foot, which is difficult to control, threatening the safety of construction and affecting the construction progress and benefits. How to allow the release of high stress and play the self-bearing role of the surrounding rock while controlling the convergence of the arch foot has become a problem to be solved. SUMMARY

[0003] To solve the above technical problems, the present application provides a double-layer corrugated plate supporting structure for controlling convergence of tunnel arch foot and a construction method thereof.

[0004] To achieve the above purpose, the present application provides the following technical solutions:

[0005] The first aspect of the present application provides a double-layer corrugated plate supporting structure for controlling convergence of tunnel arch foot, comprising a first layer of corrugated plate, a second layer of corrugated plate, a support rod, a fence, an anchor rod, a support rod and a cement pier; the second layer of corrugated plate is arranged on one side of the front surface of the first layer of corrugated plate, and the two are connected and fixed by the support rod, the bottom is closed, the transverse end is closed by the fence, the top is spaced apart to form a pouring opening, the groove space between the two corrugated plates is filled with high molecular polymer; the first corrugated plate is provided with three columns of through holes, the middle column of through holes is a grouting hole, and the two columns of through holes on both sides are anchor rod holes; the anchor rod is driven into the rock layer on the back surface of the first layer of corrugated plate through the anchor rod hole; the upper end of the support rod is connected with the front surface of the second corrugated plate, and the lower end is provided with the cement pier formed by pouring.

[0006] Further, the supporting structure further comprises a connecting seat arranged on the front surface of the first layer of corrugated plate and the back surface of the second layer of corrugated plate, the connecting seat comprises a seat body and two ear plates, the seat body is integrally fixed with the corrugated plate, the ear plates are integrally fixed on the side of the seat body away from the corrugated plate, the two ear plates are parallel and spaced apart, the same position of the ear plates is provided with a through hole, and the rod end of the support rod is also provided with a through hole, the support rod and the connecting seat are detachably connected by bolts.

[0007] Further, the supporting structure further comprises a fastener, the fastener is integrally fixed on the front surface of the second layer of corrugated plate, and the upper end of the support rod is connected with the fastener.

[0008] Further, each column of the grouting holes is provided with a plurality of grouting holes, and the plurality of grouting holes are spaced along the arc direction of the arch; each column of the anchor rod holes is provided with a plurality of anchor rod holes, and the plurality of anchor rod holes are spaced along the arc direction of the arch; the grouting holes and the anchor rod holes correspond to the height of the second corrugated plate in height.

[0009] Further, the support rods are provided with a plurality of groups, each group is provided with a plurality of support rods, the plurality of support rods in the same group are distributed in a non-planar intersecting manner in height, and the support rods in different groups are distributed at equal intervals in the length direction of the slot-shaped space.

[0010] Further, the support rods are provided with a plurality of groups, each group is provided with two support rods, each support rod is inclined and arranged with the lower end away from the second corrugated plate, the lower ends of the support rods in the same group are connected to the same cement pier, and the support rods in different groups are distributed at equal intervals in the length direction of the second corrugated plate.

[0011] Further, one column of the grouting holes and two columns of the anchor rod holes on both sides thereof form a group of functional holes, a plurality of groups of the functional holes are arranged on the first corrugated plate, and the plurality of groups of the functional holes are distributed at equal intervals in the length direction of the first corrugated plate.

[0012] The second aspect of the present application provides a construction method of a double-layer corrugated plate support structure for controlling convergence of a tunnel arch foot, which is used to implement the support structure as described in the first aspect of the present application, adopts a segmented, layered or segmented and layered construction mode, and each segment or layer construction includes the following steps:

[0013] Step S1, after the tunnel bench excavation is completed, the first corrugated plate is installed at the arch feet on both sides of the bench;

[0014] Step S2, the anchor rod is punched into the rock layer through the anchor rod hole on the first corrugated plate;

[0015] Step S3, the cement mortar is injected into the back of the first corrugated plate through the grouting hole on the first corrugated plate;

[0016] Step S4, the second corrugated plate is installed, the bottom of the second corrugated plate is closed with the first corrugated plate, the length direction end is closed with a fence, the top is spaced from the first corrugated plate to form a pouring port, and a slot-shaped space is formed between the two corrugated plates;

[0017] Step S5, the support rod between the two corrugated plates is connected through the bolt and the connecting seat;

[0018] Step S6, the high molecular polymer is injected into the slot-shaped space through the pouring port until it is filled;

[0019] Step S7, the fastener of the second layer corrugated plate connects the support rod top with the corrugated plate, and pours cement at the tail of the support rod;

[0020] Step S8, after the excavation of the next section or the next layer tunnel step is completed, the construction of the supporting structure of the next section or the next layer is carried out, and the construction mode is repeated steps S1-S7; wherein the next section refers to a certain length of step in the length direction of the tunnel, and the next layer refers to the middle step under the upper step.

[0021] The application has the following advantages:

[0022] In the support of the high ground stress tunnel, the deformation energy of the surrounding rock can be absorbed, the stress of the surrounding rock is released, the self-bearing function of the surrounding rock is played, the convergence deformation of the arch foot can be well controlled, the large deformation is avoided, the upper step and the middle step are more stable in the excavation process. The structure of the application is simple, the outline size and shape can be prefabricated according to the shape of the tunnel excavation surface, so that the construction cost is low, and the construction efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be derived from the provided drawings without creative labor.

[0024] The structure, proportion, size, etc. shown in the specification are only used to cooperate with the content disclosed in the specification, to be understood and read by those skilled in the art, and do not define the limiting conditions for the implementation of the application, so they do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be achieved by the application, should still fall within the scope of the technical content disclosed by the application.

[0025] Figure 1 A schematic view of a double-layer corrugated plate supporting structure for controlling convergence of tunnel arch foot provided by the embodiment of the application applied in a tunnel;

[0026] Figure 2 A perspective view of a double-layer corrugated plate supporting structure for controlling convergence of tunnel arch foot provided by the embodiment of the application;

[0027] Figure 3 A structure schematic view of a double-layer corrugated plate supporting structure for controlling convergence of tunnel arch foot provided by the embodiment of the application along the length direction of the tunnel;

[0028] Figure 4A schematic diagram showing the positional relationship of the functional holes in the double-layer corrugated plate support structure for controlling tunnel arch foot convergence, provided in an embodiment of the present invention.

[0029] Figure 5 A bottom perspective view of a double-layer corrugated plate support structure for controlling tunnel arch foot convergence provided in an embodiment of the present invention;

[0030] Figure 6 for Figure 5 A magnified view of A in the middle.

[0031] In the diagram: 1-Upper step, 2-Middle step, 3-First corrugated plate, 4-Second corrugated plate, 5-Enclosure, 6-Pouring port, 7-Cement block, 8-Support rod, 9-Anchor rod, 10-Support rod, 11-Anchor hole, 12-Grouting hole, 13-Fastener, 14-Connecting seat. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0034] like Figures 1-6 As shown, this invention provides a double-layer corrugated plate support structure for controlling tunnel arch foot convergence, including a first layer corrugated plate 3, a second layer corrugated plate 4, a support rod 10, a retaining wall 5, an anchor rod 9, a retaining rod 8, and a cement block 7; the second layer corrugated plate 4 is disposed on one side of the front of the first layer corrugated plate 3, and the two are connected and fixed by the support rod 10, with the bottom closed, the lateral ends closed by the retaining wall 5, and the top spaced apart to form a pouring port 6, and the groove-shaped space between the two corrugated plates is filled with a high molecular polymer; the first corrugated plate has three rows of through holes, the middle row of through holes is a grouting hole 12, and the two rows of through holes on both sides are anchor rod holes 11; the anchor rod 9 is driven into the rock stratum on the back of the first layer corrugated plate 3 through the anchor rod holes 11; the upper end of the retaining rod 8 is connected to the front of the second corrugated plate, and the lower end is provided with a cast cement block 7.

[0035] Preferably, the supporting structure further comprises a connecting seat 14 arranged on the front surface of the first corrugated plate 3 and the back surface of the second corrugated plate 4, the connecting seat 14 comprises a seat body and two ear plates, the seat body is fixedly connected with the corrugated plate, the ear plates are fixedly connected with the seat body away from the corrugated plate, the two ear plates are arranged in parallel and spaced apart, the same position of the ear plates is provided with a through hole, and the rod end of the supporting rod 10 is also provided with a through hole, and the supporting rod 10 is detachably connected with the connecting seat 14 through a bolt.

[0036] Preferably, the supporting structure further comprises a fastener 13 fixedly connected with the front surface of the second corrugated plate 4, and the upper end of the supporting rod 8 is connected with the fastener 13.

[0037] Optionally, a plurality of grouting holes 12 are arranged in each column, and the plurality of grouting holes 12 are arranged in the arc direction of the arch in a spaced-apart manner; a plurality of anchor rod holes 11 are arranged in each column, and the plurality of anchor rod holes 11 are arranged in the arc direction of the arch in a spaced-apart manner; wherein the grouting holes 12 and the anchor rod holes 11 correspond to the height of the second corrugated plate 4 in height.

[0038] Optionally, the supporting rod 10 is provided with a plurality of groups, each group is provided with a plurality of supporting rods 10, the plurality of supporting rods 10 in the same group are distributed in a non-planar intersecting manner in height, and the supporting rods 10 in different groups are distributed in an equal interval in the length direction of the groove-shaped space.

[0039] Optionally, the supporting rod 8 is provided with a plurality of groups, each group is provided with two supporting rods 8, each supporting rod 8 is arranged in an inclined manner and the lower end is away from the second corrugated plate 4, the lower ends of the supporting rods 8 in the same group are connected with the same cement pier 7, and the supporting rods 8 in different groups are distributed in an equal interval in the length direction of the second corrugated plate 4.

[0040] Optionally, a column of grouting holes 12 and two columns of anchor rod holes 11 on both sides thereof form a group of functional holes, a plurality of groups of functional holes are arranged on the first corrugated plate 3, and the plurality of groups of functional holes are distributed in an equal interval in the length direction of the first corrugated plate 3.

[0041] The application further provides a construction method of the double-layer corrugated plate supporting structure for controlling convergence of a tunnel arch spring, which is used for implementing the above supporting structure, adopts a segmented, layered or segmented and layered construction mode, and each segment or each layer construction comprises the following steps:

[0042] Step S1, after the tunnel step excavation is completed, the first corrugated plate 3 is installed at the arch spring on both sides of the step;

[0043] Step S2, the anchor rod 9 is punched into the rock layer through the anchor rod hole 11 on the first corrugated plate 3;

[0044] Step S3, the cement mortar is injected into the back surface of the first corrugated plate 3 through the grouting hole 12 on the first corrugated plate 3;

[0045] Step S4, install the second layer of corrugated plate 4, the bottom of the second layer of corrugated plate 4 forms a seal with the first layer of corrugated plate 3, the length direction end is closed with the enclosure 5, the top is spaced from the first layer of corrugated plate 3 to form a pouring port 6, and a groove type space is formed between the two corrugated plates;

[0046] Step S5, the support rod 10 in the middle of the two layers of corrugated plates is connected through bolts and connecting seats;

[0047] Step S6, the high molecular polymer is injected into the groove type space through the pouring port 6 until it is filled;

[0048] Step S7, the fastener 13 of the second layer of corrugated plate connects the top of the support rod 8 with the corrugated plate, and the cement pier 7 is poured at the tail of the support rod 8;

[0049] Step S8, after the excavation of the next section or the next layer of the tunnel step is completed, the construction of the support structure of the next section or the next layer is carried out, and the construction method is repeated steps S1-S7; wherein the next section refers to a step with a certain length excavated along the length direction of the tunnel, and the next layer refers to the middle step 2 under the upper step 1.

[0050] Generally, after the upper step 1 is excavated, a support is carried out, after the arch foot of the upper step 1 converges and deforms stably, the middle step 2 is excavated, and after the middle step 2 is excavated, a support is carried out again; this is a construction from the height space (upper and lower layer relationship); in the length direction of the tunnel, after a distance is excavated, a support is carried out; thus, the support is carried out in sections, layers, and sections and layers.

[0051] Embodiment 1

[0052] After the tunnel is excavated, the arch foot appears problems of large convergence deformation, large deformation speed, and long duration in the soft rock area where the tunnel passes through complex ground stress. The embodiment provides a double-layer corrugated plate support structure which can control the convergence deformation of the arch foot and further allow the release of high ground stress.

[0053] Reference Figures 1-6 As shown, the second layer of corrugated plate 4 has a prefabricated connecting seat 14 on the back and the front of the first layer of corrugated plate 3, the front of the second layer of corrugated plate 4 has a prefabricated fastener 13, the first layer of corrugated plate 3 has three rows of holes, two rows of anchor rod holes 11 and a row of grouting holes 12 in the middle, and the side is sealed by the enclosure 5 between the two layers of corrugated plates. The installation steps of the structure are as follows:

[0054] 1. After the upper step 1 of the tunnel is excavated, the first layer of corrugated plate 3 is installed at the arch foot on both sides of the upper step 1;

[0055] 2. The anchor rod 9 is driven into the surrounding rock through the anchor rod hole 11 on the first layer of corrugated plate 3;

[0056] 3. Inject cement mortar into the back of the first corrugated plate 3 through the injection hole 12 on the first corrugated plate 3;

[0057] 4. Install the second corrugated plate 4, and connect the support rod 10 between the two corrugated plates through the bolt and the connecting seat 14;

[0058] 5. Inject the high polymer (such as expanded foam polyurethane, expanded polyurethane foaming agent) into the groove-shaped space between the two corrugated plates through the pouring port 6 until it is filled;

[0059] 6. Connect the top of the support rod 8 to the second corrugated plate 4 through the fastener 13 of the second corrugated plate 4, and pour the cement pier 7 at the tail of the support rod 8;

[0060] 7. After the abutment convergence deformation of the upper step 1 is stable, excavate the middle step 2;

[0061] 8. After the middle step 2 is excavated, repeat the above installation steps of the double-layer corrugated plate.

[0062] After the double-layer corrugated plate support structure is installed, the abutment convergence deformation is obviously controlled, and the abutment convergence deformation is stabilized at 57.3mm.

[0063] Example 2

[0064] When the middle step 2 of the mountain tunnel with a buried depth of 120m is excavated, the problem of large abutment convergence deformation of the middle step occurs, and the convergence rate is 18.5mm / d on average. After the upper step 1 is excavated, the normal single-layer corrugated plate support structure is installed, and after the installation is completed, the middle step 2 is excavated, and then the double-layer corrugated plate structure is installed on the middle step 2, and the steps are as follows:

[0065] 1. After the middle step 2 of the tunnel is excavated, the first corrugated plate 3 is installed at the abutment of the middle step 2 on both sides;

[0066] 2. The anchor rod 9 is driven into the surrounding rock through the anchor rod hole 11 on the first corrugated plate 3;

[0067] 3. Inject cement mortar into the back of the first corrugated plate 3 through the injection hole 12 on the first corrugated plate 3;

[0068] 4. Install the second corrugated plate 4, and connect the support rod 10 between the two corrugated plates through the bolt and the connecting seat 14;

[0069] 5. Inject the high polymer through the pouring port 6 into the space between the two corrugated plates until it is filled;

[0070] 6. Connect the top of the support rod 8 to the second corrugated plate 4 through the fastener 13 of the second corrugated plate 4, and pour the cement pier 7 at the tail of the support rod 8.

[0071] After the double corrugated plate support structure is installed, the convergence rate of the middle step arch foot is reduced to 3mm / d, the effect of controlling the convergence deformation of the arch foot is obvious, and the structure can well control the convergence deformation without closing the inverted arch.

[0072] Example 3

[0073] The mountain highway tunnel with a maximum buried depth of 330m passes through a fault fracture zone, the surrounding rock grade is V, and it is in a high ground stress area after the preliminary investigation. The double corrugated plate structure is used for support, and the construction steps are as follows:

[0074] 1. After the upper step 1 of the tunnel is excavated, the first layer of corrugated plate 3 is installed at the arch foot on both sides of the upper step 1;

[0075] 2. The anchor rod 9 is punched into the surrounding rock through the anchor rod hole 11 on the first layer of corrugated plate 3;

[0076] 3. The cement mortar is injected into the wall behind the first layer of corrugated plate 3 through the grouting hole 12 on the first layer of corrugated plate 3;

[0077] 4. The second layer of corrugated plate 4 is installed, and the support rod 10 between the two layers of corrugated plates is connected through the bolt and the connecting seat 14;

[0078] 5. The high polymer is injected into the space between the two layers of corrugated plates through the pouring port 6 until it is filled;

[0079] 6. The top of the retaining rod 8 is connected to the second layer of corrugated plate 4 through the fastener 13 of the second layer of corrugated plate 4, and the cement pier 7 is poured at the tail of the retaining rod 8, and the height of the cement pier 7 can be appropriately increased;

[0080] 7. After the convergence deformation of the upper step 1 arch foot is stable, the middle step 2 is excavated;

[0081] 8. After the middle step 2 is excavated, the double corrugated plate structure is installed at the arch foot on both sides of the middle step 2, and the above installation steps of the double corrugated plate are repeated.

[0082] The two layers of corrugated plates of the structure are equivalent to a ductile support structure, and the high polymer poured in the middle is equivalent to a flexible layer. After the double corrugated plate support structure is used, the convergence deformation of the tunnel is well controlled and a part of the deformation energy of the surrounding rock is absorbed, and a part of the high ground stress is released.

[0083] Although the present application has been described in detail by the general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application are within the scope of the present application.

Claims

1. A double-layer corrugated plate support structure for controlling tunnel arch foot convergence, characterized in that, The system includes a first corrugated plate, a second corrugated plate, support rods, a retaining wall, anchor rods, retaining rods, and cement blocks. The second corrugated plate is positioned on one side of the front of the first corrugated plate, and the two are connected and fixed by the support rods. The bottom is closed, the lateral ends are closed by the retaining wall, and the top is spaced apart to form a pouring port. A groove-shaped space is formed between the two corrugated plates, and the groove-shaped space is filled with a high-molecular polymer. The first corrugated plate has three rows of through holes, the middle row of through holes being grouting holes, and the two rows of through holes on both sides being anchor rod holes. The anchor rods are driven into the rock strata on the back of the first corrugated plate through the anchor rod holes. The upper end of the retaining rod is connected to the front of the second corrugated plate, and the lower end is provided with the cast-in-place cement block. Connecting seats are respectively provided on the front side of the first layer of corrugated plate and the back side of the second layer of corrugated plate. Each connecting seat includes a seat body and two ear plates. The seat body is integrally fixed to the corrugated plate, and the ear plates are integrally fixed to the side of the seat body away from the corrugated plate. The two ear plates are parallel and spaced apart. Through holes are provided at the same position on the ear plates. Through holes are also provided at the end of the support rod. The support rod is detachably connected to the connecting seat by bolts.

2. The double-layer corrugated plate support structure for controlling tunnel arch foot convergence according to claim 1, characterized in that, The support structure also includes fasteners, which are integrally fixed to the front of the second corrugated plate, and the upper end of the support rod is connected to the fasteners.

3. The double-layer corrugated plate support structure for controlling tunnel arch foot convergence according to claim 1, characterized in that, Each column of the grouting holes is provided with multiple holes, which are spaced apart along the arc direction of the arch; each column of the anchor bolt holes is provided with multiple holes, which are spaced apart along the arc direction of the arch; wherein, the height of the grouting holes and the anchor bolt holes corresponds to the height of the second layer of corrugated plate.

4. The double-layer corrugated plate support structure for controlling tunnel arch foot convergence according to claim 1, characterized in that, The support rods are provided in multiple groups, and each group has multiple rods. The multiple support rods in the same group are distributed in a cross-shaped manner at different heights, and the support rods in different groups are distributed at equal intervals along the length of the groove space.

5. The double-layer corrugated plate support structure for controlling tunnel arch foot convergence according to claim 1, characterized in that, The support rods are provided in multiple groups, with two rods in each group. Each support rod is inclined and its lower end is away from the second corrugated plate. The lower ends of the support rods in the same group are connected to the same cement block. The support rods in different groups are distributed at equal intervals along the length of the second corrugated plate.

6. The double-layer corrugated plate support structure for controlling tunnel arch foot convergence according to claim 1, characterized in that, One row of grouting holes and two rows of anchor bolt holes on both sides constitute a set of functional holes. Multiple sets of functional holes are provided on the first layer of corrugated plate, and the multiple sets of functional holes are evenly distributed along the length direction of the first layer of corrugated plate.

7. A construction method for a double-layer corrugated plate support structure for controlling tunnel arch foot convergence, characterized in that, For implementing the support structure as described in any one of claims 1-6, a segmented, layered, or segmented-layered construction method is adopted, and the construction of each segment or layer includes the following steps: Step S1: After the tunnel steps are excavated, the first layer of corrugated plates is installed at the arch feet on both sides of the steps. Step S2: Drive the anchor bolt into the rock stratum through the anchor bolt hole on the first corrugated plate; Step S3: Inject cement mortar into the back of the first corrugated plate through the grouting holes on the first corrugated plate; Step S4: Install the second corrugated plate. The bottom of the second corrugated plate is closed with the first corrugated plate. The ends in the length direction are closed with a barrier. The top is left with a gap to form a pouring gate. A groove-shaped space is formed between the two corrugated plates. Step S5: Connect the support rod between the two corrugated plates using bolts and connecting seats; Step S6: Inject the polymer into the trough space through the pouring port until it is full; Step S7: The fasteners of the second corrugated plate connect the top of the support rod to the corrugated plate, and a cement block is poured at the tail of the support rod. Step S8: After the excavation of the next section or the next layer of tunnel bench is completed, the construction of the support structure of the next section or the next layer is carried out. The construction method repeats the above steps S1-S7. The next section refers to a bench of a certain length along the tunnel length direction, and the next layer refers to the middle bench below the upper bench.

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