Reinforcing wall for shallow-buried and unsymmetrical pressure multi-arch tunnel and construction method thereof

Abstract

The embodiment of the application provides a shallow-buried bias multi-arch tunnel reinforcing wall and a construction method thereof, and relates to the technical field of tunnel construction. After the support framework is fixed, the backfilling layer is filled in the lower half of the filling cavity and the upper surface of the backfilling layer is roughened to preliminarily embed the support framework. Then, the steel pipe piles are drilled in the backfilling layer and the base rock mass in sequence. The roughening treatment of the backfilling layer can better combine with the cast concrete body, so that the finally formed wall body with good rigidity directly acts on the inverted arch filling layer and the partition wall. The stress of the wall body can be directly transmitted to the base rock mass through the steel pipe piles to resist the mountain bias, thereby reducing the risk of cracks in the lining structure of the partition wall, enhancing the shear damage constraint of the tunnel structure under the accidental action of the mountain, ensuring the safety of the tunnel structure, and further reducing and eliminating the rework and repair problems caused by the damage of the tunnel structure, ensuring smooth operation, and saving treatment costs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a shallow-buried bias multi-arch tunnel reinforcing wall and a construction method thereof. BACKGROUND

[0002] In the construction of shallow-buried bias multi-arch tunnels in mountainous areas, cracks in tunnel lining structures are common, and the proportion of load deformation cracks in tunnel lining concrete diseases has increased year by year, which is difficult to treat and is not easy to eradicate, and has attracted the attention of the majority of engineering and technical personnel. Tunnel lining structures play a key role in safety during in-hole construction and later operation. The causes of cracks are very complex, often the result of the combined action of multiple adverse factors. Among them, the deformation of surrounding rock, uneven load, high ground stress, and poor contact zone are prone to cause cracks in the lining structure; cracks not only affect the appearance, but also leave hidden dangers to the structure; therefore, effective and reasonable engineering and technical measures must be taken during construction to control, reduce and avoid cracks. The initial support structure and lining concrete of the mid-partition wall multi-arch part in the shallow-buried bias multi-arch tunnel without a pilot tunnel are most stressed and prone to cracks.

[0003] The prior art is usually passive after the cracks are generated and no longer develop by injecting special slurry (epoxy resin) material for reinforcement, but this technology cannot completely eliminate the generation of cracks, and with the passage of time or rain season period, geological disasters, earthquakes and other objective factors frequently, cracks have the possibility of extension and regeneration.

[0004] Therefore, there is an urgent need for a technical solution that can reduce the risk of cracks in the lining structure of the mid-partition wall. SUMMARY

[0005] The purpose of the present application includes, for example, providing a shallow-buried bias multi-arch tunnel reinforcing wall and a construction method thereof, which can reduce the risk of cracks in the lining structure of the mid-partition wall.

[0006] Embodiments of the present application can be implemented as follows:

[0007] In a first aspect, the present application provides a shallow-buried bias multi-arch tunnel reinforcing wall for a mid-partition wall arranged in a shallow-buried side tunnel, wherein a filling cavity is formed between the inverted arch filling layer of the shallow-buried side tunnel and the bottom of the mid-partition wall, and the shallow-buried bias multi-arch tunnel reinforcing wall comprises:

[0008] a support framework fixed to the mid-partition wall, and the bottom of the support framework extends into the filling cavity;

[0009] a backfilling concrete layer filled in the lower half of the filling cavity, and the upper surface of the backfilling concrete layer is roughened;

[0010] Steel pipe piles are drilled in the backfill concrete layer, and the bottom end of the steel pipe piles extends into the base rock mass;

[0011] The cast concrete body covers the upper half of the filling cavity and the top end of the steel pipe piles.

[0012] In an optional embodiment, the support framework includes back arch steel, inclined support steel, and connecting steel. A plurality of the connecting steel is vertically spaced and fixed to the partition wall. Each of the connecting steel extends longitudinally. Both ends of each of the connecting steel are connected with the back arch steel. The back arch steel is vertically fixed to the partition wall and is adapted to the shape of the partition wall. One end of the inclined support steel is fixed to the inverted arch filling layer and the bottom end of the back arch steel. The other end of the inclined support steel is fixed to the middle part of the back arch steel.

[0013] In an optional embodiment, there are two steel pipe piles on the same cross section of the partition wall. The two steel pipe piles are divided into a first steel pipe pile and a second steel pipe pile. The first steel pipe pile is vertically arranged. The second steel pipe pile is located on the side of the first steel pipe pile away from the partition wall. The second steel pipe pile is inclined relative to the first steel pipe pile. In a vertically downward direction, the distance between the first steel pipe pile and the second steel pipe pile gradually increases.

[0014] In an optional embodiment, the steel pipe pile includes a steel flower pipe and a plurality of steel tendon. The plurality of steel tendon is arranged in the steel flower pipe and is fixed by grouting.

[0015] In an optional embodiment, the shallow-buried bias multi-arch tunnel reinforcing wall further includes:

[0016] The reinforcing framework has a plurality of steel bars in the horizontal direction, the vertical direction, and the longitudinal direction, which are wrapped by the cast concrete body.

[0017] And / or,

[0018] The drain pipe is wrapped by the backfill concrete layer for drainage.

[0019] And / or,

[0020] The anchor is implanted in the partition wall and is fixedly connected with the end of the support framework.

[0021] In a second aspect, the present application provides a construction method of a shallow-buried bias multi-arch tunnel reinforcing wall. The method is used to form a reinforcing wall at a partition wall in a shallow-buried side tunnel. A filling cavity is formed between the inverted arch filling layer of the shallow-buried side tunnel and the bottom of the partition wall. The method includes:

[0022] The support framework is fixed to the partition wall, and the bottom of the support framework extends into the filling cavity.

[0023] backfilling the lower half of the filling cavity with concrete to form a backfill concrete layer and roughening the upper surface of the backfill concrete layer;

[0024] drilling a steel pipe pile into the backfill concrete layer, with the bottom end of the steel pipe pile extending into the base rock mass;

[0025] pouring concrete to cover the support framework, the upper half of the filling cavity, and the top end of the steel pipe pile, forming a poured concrete body.

[0026] In optional embodiments, the step of drilling a steel pipe pile into the backfill concrete layer, with the bottom end of the steel pipe pile extending into the base rock mass, includes:

[0027] drilling downward from the backfill concrete layer to the base rock mass using a drill rig to form an installation hole and clean it;

[0028] fixing a steel pipe pile in the installation hole.

[0029] In optional embodiments, the steel pipe pile includes a steel pipe and a plurality of steel tendon bundles, and the step of fixing a steel pipe pile in the installation hole includes:

[0030] threading the steel pipe into the installation hole;

[0031] threading the plurality of steel tendon bundles into the steel pipe;

[0032] grouting the steel pipe.

[0033] In optional embodiments, the step of pouring concrete includes using a steel formwork to pour concrete, and after pouring is complete, removing the formwork, wherein the steel formwork is fixed with steel pipe diagonal bracing, and inside the steel formwork, is supported with concrete blocks and square timber, and the concrete is poured in layers using a pumping method.

[0034] In optional embodiments, before the step of backfilling the lower half of the filling cavity with concrete, the construction method further includes arranging a drainage pipe at the bottom of the filling cavity;

[0035] and / or,

[0036] Before the step of pouring concrete, the construction method further includes arranging a reinforcing framework having a plurality of steel bars in the transverse, vertical, and longitudinal directions in the partition wall and the filling cavity; and / or, embedding anchor bars in the partition wall, with the end portions fixedly connected to the support framework.

[0037] The beneficial effects of embodiments of the present application include, for example:

[0038] The shallow-buried bias-arch tunnel reinforcing wall and the construction method thereof, after the support framework is fixed, the backfilling concrete layer is filled in the lower half of the filling cavity and the upper surface of the backfilling concrete layer is roughened to preliminarily embed the support framework, and then the steel pipe piles are drilled in the backfilling concrete layer and the base rock mass in sequence, the roughening treatment of the backfilling concrete layer can better combine with the cast concrete body, so that the finally formed wall body with good rigidity directly acts on the inverted arch filling layer and the partition wall, and the stress of the wall body can be directly transmitted to the base rock mass through the steel pipe piles to resist the mountain bias, thereby reducing the crack risk of the lining structure of the partition wall, enhancing the shear damage constraint of the tunnel structure under the accidental action of the mountain, ensuring the safety of the tunnel structure, and further reducing and eliminating the rework and repair problems caused by the damage of the tunnel structure, ensuring smooth operation, saving treatment cost. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0040] Figure 1 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application.

[0041] Figure 2 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application. Figure 1 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application.

[0042] Figure 3 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application. Figure 2 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application.

[0043] Figure 4 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application. Figure 2 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application.

[0044] Figure 5 The figure is a schematic diagram of a tunnel cross section provided with the shallow-buried bias-arch tunnel reinforcing wall of the present application.

[0045] Figure legend: 1-steel pipe pile; 11-steel tendon; 12-steel flower pipe; 2-anchor bar; 3-inclined support steel; 4-back arch steel; 5-connection steel; 6-cast concrete body; 7-backfilling concrete layer; 8-drainage pipe. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0048] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0049] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0050] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0051] The inventor found that the shallow-buried side tunnel in the bias-arch tunnel is away from the center of the mountain relative to the bias side tunnel, so the pressure on the partition wall is biased to the shallow-buried side tunnel, thereby cracks are prone to occur. Therefore, the inventor designs a reinforcing wall in the shallow-buried side tunnel to support the partition wall, so as to improve the rigidity of the partition wall and thereby reduce the risk of cracks. The following will specifically describe the embodiments of the present application, and it should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0052] Please refer to Figure 1 and Figure 2The embodiment of the present application provides a shallow-buried bias multi-arch tunnel reinforcing wall, which is arranged at a middle partition wall in a shallow-buried side tunnel, wherein a filling cavity is formed between an inverted arch filling layer of the shallow-buried side tunnel and a bottom of the middle partition wall, and the shallow-buried bias multi-arch tunnel reinforcing wall comprises a support framework, a backfilling concrete layer 7, a steel pipe pile 1 and a cast concrete body 6. The support framework is fixed to the middle partition wall, and a bottom of the support framework extends into the filling cavity. The backfilling concrete layer 7 is filled in a lower half of the filling cavity, and an upper surface of the backfilling concrete layer 7 is roughened. The steel pipe pile 1 is drilled in the backfilling concrete layer 7, and a bottom end of the steel pipe pile 1 extends into a base rock mass. The cast concrete body 6 covers an upper half of the filling cavity and the support framework and a top end of the steel pipe pile 1.

[0053] Therefore, after being fixed by the support framework, the backfilling concrete layer 7 is filled in the lower half of the filling cavity to preliminarily embed the support framework, the steel pipe pile 1 is drilled in the backfilling concrete layer 7 and the base rock mass in sequence, and the roughened upper surface of the backfilling concrete layer 7 can be better combined with the cast concrete body 6, so that a wall body with good rigidity is finally formed to directly act on the inverted arch filling layer and the middle partition wall, and the stress of the wall body can be directly transmitted to the base rock mass through the steel pipe pile 1 to resist the mountain bias, thereby reducing the risk of cracks in the lining structure of the middle partition wall, enhancing the constraint of shear damage of the tunnel structure under the accidental action of the mountain, ensuring the safety of the tunnel structure, further reducing and eliminating the problem of rework and repair due to the damage of the tunnel structure, ensuring smooth operation, and saving treatment costs.

[0054] In combination Figure 3 In the embodiment, the support framework comprises a back arch steel 4, an inclined bracing steel 3 and a connecting steel 5, the back arch steel 4 can be an I25b I-shaped steel, the inclined bracing steel 3 can be an I18 or above I-shaped steel, and the connecting steel 5 can be an I18 I-shaped steel. A plurality of connecting steels 5 are vertically and spaced fixed to the middle partition wall, each connecting steel 5 extends longitudinally, and each connecting steel 5 is connected with the back arch steel 4 at both ends, the back arch steel 4 is vertically fixed to the middle partition wall and is matched with the shape of the middle partition wall, one end of the inclined bracing steel 3 is fixed to the inverted arch filling layer and the bottom end of the back arch steel 4, and the other end of the inclined bracing steel 3 is fixed to the middle part of the back arch steel 4.

[0055] There are two steel pipe piles 1 on the same cross section of the middle partition wall, the two steel pipe piles 1 are divided into a first steel pipe pile 1 and a second steel pipe pile 1, the first steel pipe pile 1 is vertically arranged, the second steel pipe pile 1 is located on a side of the first steel pipe pile 1 away from the middle partition wall, and the second steel pipe pile 1 is inclined relative to the first steel pipe pile 1, wherein in the vertical downward direction, the spacing between the first steel pipe pile 1 and the second steel pipe pile 1 gradually increases, thereby improving the supporting force of the steel pipe pile 1 on the reinforcing wall and further improving the rigidity of the reinforcing wall.

[0056] In combination Figure 4The steel pipe pile 1 comprises a steel flower pipe 12 and a plurality of steel bars 11, the plurality of steel bars 11 are arranged in the steel flower pipe 12, and the grout during grouting can be combined with the backfill concrete layer 7 and the base rock mass through the holes on the steel flower pipe 12, so that the fixing of the steel flower pipe 12 and the fixing of the steel bars 11 and the steel flower pipe 12 are realized through grouting, and the rigidity of the whole steel pipe pile 1 is high. The diameter of the steel bar 11 can be 32 mm, the diameter of the steel flower pipe 12 can be 108 mm, and the length of the steel flower pipe 12 and the steel bar 11 can be 15 m, so that the steel pipe pile 1 can pass through the support structure and extend into the base rock mass. The initial pressure of the grouting pressure during the grouting process can be 0.5-1 Mpa, and the pressure holding time is 2-3 min. In the longitudinal direction of the tunnel length direction, the setting interval of the steel pipe pile 1 can be 3 m.

[0057] In the embodiment, the reinforcing wall of the shallow-buried bias multi-arch tunnel further comprises a reinforcing framework drainage pipe 8 and an anchor bar 2. The reinforcing framework has a plurality of steel bars in the transverse direction, the vertical direction and the longitudinal direction, and is wrapped by the cast concrete 6 to sequentially improve the rigidity of the wall. The plurality of steel bars can be five types and sizes, i.e. N1: φ22@10, N2: φ16@15, N3: φ16@15, N4: φ10@15, and N5: φ16@20.

[0058] The drainage pipe 8 can be a φ250 mm HDPE double-wall perforated corrugated pipe, which extends in the longitudinal direction, i.e. the length direction of the tunnel, and is wrapped by the backfill concrete layer 7 for drainage.

[0059] The anchor bar 2 is implanted in the middle partition wall from the side away from the center of the mountain, and the end is fixedly connected with the support framework. The transverse direction is the transverse direction of the tunnel, and the end of the anchor bar 2 and the back arch steel 4 of the support framework are fixedly connected in the form of double-sided welding. Thus, the integrity of the middle partition wall lining structure is fully ensured, thereby enhancing the crack resistance of the middle partition wall. The diameter of the anchor bar 2 can be 32 mm, and a plurality of anchor bars 2 are arranged in the vertical direction with an interval of 80 cm, and the anchor bars 2 are arranged at an interval of 100 cm in the longitudinal direction of the tunnel.

[0060] Please refer to Figure 5 The embodiment of the present application further provides a construction method of the reinforcing wall of the shallow-buried bias multi-arch tunnel, which is used for forming the reinforcing wall of the shallow-buried bias multi-arch tunnel in the middle partition wall of the shallow-buried side tunnel, and the method comprises the following steps:

[0061] The support framework is fixed in the middle partition wall, and the bottom of the support framework extends into the filling cavity;

[0062] The lower half of the filling cavity is backfilled with concrete to form the backfill concrete layer 7, and the upper surface of the backfill concrete layer 7 is roughened;

[0063] The steel pipe pile 1 is drilled in the backfill concrete layer 7, and the bottom end of the steel pipe pile 1 extends into the base rock mass;

[0064] The concrete pouring is performed to cover the support framework, the upper half of the filling cavity and the top end of the steel pipe pile 1, and to form the poured concrete 6.

[0065] In the step of backfilling the lower half of the filling cavity with concrete to form the backfill concrete layer 7 and roughening the upper surface of the backfill concrete layer 7, the lower half of the filling cavity is backfilled with C40 concrete, vibrated and compacted to form the backfill concrete layer 7, and the upper surface of the backfill concrete layer 7 is roughened.

[0066] In the step of drilling the steel pipe pile 1 in the backfill concrete layer 7, and extending the bottom end of the steel pipe pile 1 into the base rock mass, it comprises:

[0067] The drilling machine is used to drill downward from the backfill concrete layer 7 until the base rock mass is drilled into, to form the installation hole and clean it up;

[0068] The steel pipe pile 1 is fixed in the installation hole.

[0069] In the step of fixing the steel pipe pile 1 in the installation hole, it comprises:

[0070] The steel pipe 12 is inserted into the installation hole;

[0071] A plurality of steel bars 11 are inserted into the steel pipe 12;

[0072] The steel pipe 12 is pressure grouted.

[0073] In the step of performing the concrete pouring, the steel formwork is used for the concrete pouring, and after the pouring is completed, the formwork is removed, wherein the steel formwork is fixed by the steel pipe diagonal bracing, the inside of the steel formwork is supported by the concrete cushion block and the square timber, the concrete is poured and vibrated in layers by the pumping mode, and after the formwork is removed, the water is sprayed for curing.

[0074] Before the step of backfilling the lower half of the filling cavity with concrete, the construction method further comprises arranging the drainage pipe 8 at the bottom of the filling cavity;

[0075] Before the step of performing the concrete pouring, the construction method further comprises arranging the reinforcing framework with a plurality of steel bars in the transverse direction, the vertical direction and the longitudinal direction in the partition wall and the filling cavity.

[0076] Before the step of performing the concrete pouring, the construction method further comprises implanting the anchor bar 2 into the partition wall and fixedly connecting it with the support framework.

[0077] In summary, the shallow-buried bias-arch tunnel reinforcing wall and the construction method thereof, after the support framework is fixed, the backfilling layer 7 is filled in the lower half of the filling cavity and the upper surface of the backfilling layer 7 is roughened to preliminarily embed the support framework, then the steel pipe pile 1 is drilled in the backfilling layer 7 and the base rock mass in sequence, the roughening treatment of the backfilling layer 7 can better combine with the cast concrete 6, so that the finally formed wall body with good rigidity directly acts on the inverted arch filling layer and the partition wall, the stress of the wall body can be directly transmitted to the base rock mass through the steel pipe pile 1 to resist the mountain bias pressure, thereby the crack risk of the lining structure of the partition wall can be reduced, the shear damage constraint of the tunnel structure under the accidental action of the mountain is enhanced, the safety of the tunnel structure is ensured, and then the rework and repair problems caused by the damage of the tunnel structure are reduced and eliminated, the smooth operation is ensured, and the treatment cost is saved.

[0078] The above merely illustrates the specific implementation of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A shallow-buried bias multi-arch tunnel reinforcing wall, characterized in that, The application discloses a reinforcing wall for a middle partition wall in a shallow-buried side tunnel, wherein a filling cavity is formed between an inverted arch filling layer of the shallow-buried side tunnel and a bottom of the middle partition wall, and the reinforcing wall comprises: a support framework fixed to the middle partition wall, and a bottom of the support framework extending into the filling cavity; a backfilling concrete layer filled in a lower half of the filling cavity, and an upper surface of the backfilling concrete layer being roughened; a steel pipe pile drilled in the backfilling concrete layer, and a bottom end of the steel pipe pile extending into a base rock mass; a cast concrete body covering an upper half of the filling cavity and a top end of the support framework and the steel pipe pile; wherein the support framework comprises back arch steel, inclined support steel and connecting steel, a plurality of the connecting steel is fixed vertically and spaced apart on the middle partition wall, each of the connecting steel extends longitudinally, both ends of each of the connecting steel is connected with the back arch steel, the back arch steel is fixed vertically on the middle partition wall and is adapted to a shape of the middle partition wall, one end of the inclined support steel is fixed to the inverted arch filling layer and a bottom end of the back arch steel, and the other end of the inclined support steel is fixed to a middle part of the back arch steel.

2. The shallow-buried bias continuous arch tunnel reinforcing wall according to claim 1, characterized in that, There are two steel pipe piles on the same cross section of the middle partition wall, the two steel pipe piles are divided into a first steel pipe pile and a second steel pipe pile, the first steel pipe pile is arranged vertically, the second steel pipe pile is located on a side of the first steel pipe pile away from the middle partition wall, and the second steel pipe pile is inclined relative to the first steel pipe pile, wherein along a vertical downward direction, a distance between the first steel pipe pile and the second steel pipe pile gradually increases.

3. The shallow-buried bias continuous arch tunnel reinforcing wall according to claim 1, characterized in that, The steel pipe pile comprises a steel flower pipe and a plurality of steel tendon bundles, the plurality of steel tendon bundles are arranged in the steel flower pipe and are fixed by grouting.

4. The shallow-buried bias continuous arch tunnel reinforcing wall according to claim 1, characterized in that, The reinforcing wall further comprises: a reinforcing framework having a plurality of steel bars in a horizontal direction, a vertical direction and a longitudinal direction, and being wrapped by the cast concrete body; and / or, a drain pipe wrapped by the backfilling concrete layer for drainage; and / or, anchor bars implanted in the middle partition wall and fixedly connected with the support framework at end portions.

5. A construction method of a shallow-buried bias multi-arch tunnel reinforcing wall, characterized in that, The application discloses a reinforcing wall for a middle partition wall in a shallow-buried side tunnel, wherein a filling cavity is formed between an inverted arch filling layer of the shallow-buried side tunnel and a bottom of the middle partition wall, and the reinforcing wall comprises: a support framework fixed to the middle partition wall, and a bottom of the support framework extending into the filling cavity; a backfilling concrete layer filled in a lower half of the filling cavity, and an upper surface of the backfilling concrete layer being roughened; a steel pipe pile drilled in the backfilling concrete layer, and a bottom end of the steel pipe pile extending into a base rock mass; a cast concrete body covering an upper half of the filling cavity and a top end of the support framework and the steel pipe pile; 6. The construction method of the shallow-buried bias multi-arch tunnel reinforcing wall according to claim 5, characterized in that, wherein the support framework comprises back arch steel, inclined support steel and connecting steel, a plurality of the connecting steel is fixed vertically and spaced apart on the middle partition wall, each of the connecting steel extends longitudinally, both ends of each of the connecting steel is connected with the back arch steel, the back arch steel is fixed vertically on the middle partition wall and is adapted to a shape of the middle partition wall, one end of the inclined support steel is fixed to the inverted arch filling layer and a bottom end of the back arch steel, and the other end of the inclined support steel is fixed to a middle part of the back arch steel. There are two steel pipe piles on the same cross section of the middle partition wall, the two steel pipe piles are divided into a first steel pipe pile and a second steel pipe pile, the first steel pipe pile is arranged vertically, the second steel pipe pile is located on a side of the first steel pipe pile away from the middle partition wall, and the second steel pipe pile is inclined relative to the first steel pipe pile, wherein along a vertical downward direction, a distance between the first steel pipe pile and the second steel pipe pile gradually increases. The steel pipe pile comprises a steel flower pipe and a plurality of steel tendon bundles, the plurality of steel tendon bundles are arranged in the steel flower pipe and are fixed by grouting. The reinforcing wall further comprises: a reinforcing framework having a plurality of steel bars in a horizontal direction, a vertical direction and a longitudinal direction, and being wrapped by the cast concrete body; and / or, a drain pipe wrapped by the backfilling concrete layer for drainage; and / or, anchor bars implanted in the middle partition wall and fixedly connected with the support framework at end portions. The application discloses a reinforcing wall for a middle partition wall in a shallow-buried side tunnel, wherein a filling cavity is formed between an inverted arch filling layer of the shallow-buried side tunnel and a bottom of the middle partition wall, and the reinforcing wall comprises: a support framework fixed to the middle partition wall, and a bottom of the support framework extending into the filling cavity; a backfilling concrete layer filled in a lower half of the filling cavity, and an upper surface of the backfilling concrete layer being roughened; a steel pipe pile drilled in the backfilling concrete layer, and a bottom end of the steel pipe pile extending into a base rock mass; a cast concrete body covering an upper half of the filling cavity and a top end of the support framework and the steel pipe pile; wherein the support framework comprises back arch steel, inclined support steel and connecting steel, a plurality of the connecting steel is fixed vertically and spaced apart on the middle partition wall, each of the connecting steel extends longitudinally, both ends of each of the connecting steel is connected with the back arch steel, the back arch steel is fixed vertically on the middle partition wall and is adapted to a shape of the middle partition wall, one end of the inclined support steel is fixed to the inverted arch filling layer and a bottom end of the back arch steel, and the other end of the inclined support steel is fixed to a middle part of the back arch steel. There are two steel pipe piles on the same cross section of the middle partition wall, the two steel pipe piles are divided into a first steel pipe pile and a second steel pipe pile, the first steel pipe pile is arranged vertically, the second steel pipe pile is located on a side of the first steel pipe pile away from the middle partition wall, and the second steel pipe pile is inclined relative to the first steel pipe pile, wherein along a vertical downward direction, a distance between the first steel pipe pile and the second steel pipe pile gradually increases. The steel pipe pile comprises a steel flower pipe and a plurality of steel tendon bundles, the plurality of steel tendon bundles are arranged in the steel flower pipe and are fixed by grouting. The reinforcing wall further comprises: a reinforcing framework having a plurality of steel bars in a horizontal direction, a vertical direction and a longitudinal direction, and being wrapped by the cast concrete body; and / or, a drain pipe wrapped by the backfilling concrete layer for drainage; and / or, anchor bars implanted in the middle partition wall and fixedly connected with the support framework at end portions.

7. The construction method of the shallow-buried bias multi-arch tunnel reinforcing wall according to claim 6, characterized in that, The steel pipe pile comprises a steel flower pipe and a plurality of steel bars, the step of fixing the steel pipe pile in the installation hole comprises: putting the steel flower pipe into the installation hole; putting a plurality of steel bars into the steel flower pipe; pressure grouting the steel flower pipe.

8. The construction method of the shallow-buried bias continuous arch tunnel reinforcing wall according to claim 5, characterized in that, The step of pouring concrete comprises pouring concrete by using a steel formwork, and the formwork is removed after pouring is completed, wherein the steel formwork is fixed by using a steel pipe diagonal bracing, a concrete cushion and a square timber are used for supporting inside the steel formwork, and concrete is poured in layers by using a pumping mode.

9. The method for constructing a shallow-buried bias multi-arch tunnel reinforcing wall according to claim 5, characterized in that, Before the step of backfilling the lower half of the filling cavity with concrete, the construction method further comprises arranging a drainage pipe at the bottom of the filling cavity; and / or, Before the step of pouring concrete, the construction method further comprises arranging a reinforcing framework with a plurality of steel bars in horizontal, vertical and longitudinal directions in the partition wall and the filling cavity; and / or, implanting anchor bars in the partition wall, and fixing the end portions of the anchor bars to the supporting framework.

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