Supporting method for large space high sidewall of underground chamber

Abstract

The application discloses a supporting method for a large-space high-side-wall underground chamber, which comprises the following steps: performing arch advanced support, excavating a first layer I of a horizontal passage, performing end anchor rod and end I-shaped steel construction of the horizontal passage, installing first layer anchor cables MS1, installing a guide wall in a first layer range, excavating a second layer II of the horizontal passage, installing second and third rows of anchor cables MS2 and MS3, installing a guide wall in a second layer range, excavating a third layer III of the horizontal passage, installing fourth and fifth rows of anchor cables MS4 and MS5, installing a guide wall in a third layer range, performing main body construction of the station, performing upper half-section lining of the main body structure, performing main body structure construction in the horizontal passage range, continuously excavating downward and timely performing side wall anchor rod and anchor cable MS6 construction, and performing lower lining of the station. The application uses anchor cables to perform supporting construction of the large-space high-side-wall underground chamber, saves engineering cost, provides large counterforce through the anchor cables, reduces construction risk, reduces process conversion in the construction process, and achieves the purpose of rapid construction.

Description

Technical Field

[0001] This invention belongs to the field of construction technology for large-space underground chambers, specifically relating to a support method for high sidewalls in large-space underground chambers. Background Technology

[0002] With the rapid development of my country's rail transit and the continuous expansion of urban subway network construction, the construction and design of underground chambers such as subway stations are becoming increasingly common. Subway stations have large excavation cross-sections, and the excavation process generally involves first constructing a cross passage, and then using the cross passage to open portals on one or both sides to construct the main structure of the station. During the construction of the cross passage, temporary cross bracing is used to divide the large space into smaller spaces to reduce construction risks. When opening portals on the side walls of the cross passage to construct the main station structure, the temporary supports will lose their load-bearing points as one side wall of the cross passage is demolished, posing a high risk.

[0003] Traditional construction methods typically use lateral anchors to provide temporary support and reaction force. However, this method provides relatively small reaction force, resulting in large deformation and slow construction speed when excavating large underground chambers. Therefore, it is particularly important to study a support method and construction technique for high sidewalls that can be rapidly constructed in large underground chambers. Summary of the Invention

[0004] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a support method for high side walls in large underground chambers.

[0005] The technical solution of this invention is: a method for supporting high sidewalls in a large underground chamber, comprising the following steps:

[0006] i. Construct arch support for the transverse passage and excavate the first layer I of the transverse passage;

[0007] ii. Anchor bolts and I-beams at the ends of the construction cross passage;

[0008] iii. Within the first layer I of the transverse passage, set up a drilling rig, drill holes, and install the first layer of anchor cables MS1;

[0009] iv. Pre-install the main structure's advanced support at the horse-head door opening on the side wall of the first floor of the transverse passage, and install the guide wall within the first floor range;

[0010] v. Excavate the second layer of the transverse passage (II);

[0011] vi. Anchor bolts and I-beams at the ends of the construction cross passage;

[0012] vii. Within the second layer of the transverse passage (II), set up a drilling rig, drill holes, and install the second row of anchor cables MS2 and the third row of anchor cables MS3;

[0013] ⅷ. Pre-install the main structure's advanced support at the horse-head door opening on the side wall of the second floor (II) of the transverse passage, and install the guide wall within the second floor area;

[0014] ⅸ. Excavate the third layer (III) of the transverse passage;

[0015] x. Anchor bolts and I-beams at the ends of the construction cross passage;

[0016] xi. Within the third layer (III) of the transverse passage, set up a drilling rig, drill holes, and install the fourth row of anchor cables MS4 and the fifth row of anchor cables MS5;

[0017] xii. Pre-install the main structure's pre-support at the horse-head door opening on the side wall of the third floor (III) of the transverse passage; install guide walls within the third floor area;

[0018] ⅹiii. After the anchor cables reach the design strength, open the gate on the side wall of the cross passage to construct the main station structure and promptly carry out the initial support of the main structure;

[0019] xiv. Lining of the upper half of the main structure;

[0020] xv. Main structure within the construction cross passageway area;

[0021] xⅵ. After the upper half section lining of the main structure and the main structure within the transverse passage reach the design strength, continue to excavate the surrounding rock within the fifth layer V to the design height of the anchor cable, and promptly construct the side wall anchors and anchor cables MS6.

[0022] xvii. Repeat step xvii until the entire underground chamber has been excavated;

[0023] xⅷ. Construct the lower lining of the station to effectively connect the lower lining of the station with the main structure within the cross passage.

[0024] Furthermore, step i, which involves constructing the arch support for the transverse passage and excavating the first layer I of the transverse passage, also includes the following processes:

[0025] During the excavation process, it is necessary to promptly construct the initial support of the transverse arch, the side wall anchors, the initial support of the side walls, and the first temporary steel support at the bottom of the transverse passage.

[0026] Furthermore, step ii, the construction of the end anchor bolts and end I-beams of the cross passage, also includes the following processes:

[0027] First, the end I-beams are connected together with reinforcing bars;

[0028] Then, the end I-beams are connected to the initial support of the arch.

[0029] Furthermore, in steps ⅵ and ⅹ, during the construction of the end anchor bolts and end I-beams of the cross passage, the end I-beams are connected together with connecting steel bars.

[0030] Furthermore, step v, excavating the second layer II of the transverse passage, also includes the following processes:

[0031] During the excavation process, the initial support of the side walls of the cross passage, the side wall anchors, and the second temporary steel support at the bottom of the cross passage were constructed in a timely manner.

[0032] Furthermore, in step ⅷ, the main structure advance support is installed in advance at the horse-head door opening on the side wall of the second layer II range of the transverse passage. During the installation of the guide wall within the second layer range, in order to facilitate construction, part of the first temporary steel support at the bottom of the transverse passage can be removed.

[0033] Furthermore, step ⅸ, excavating the third layer (III) of the transverse passage, also includes the following processes:

[0034] During the excavation process, the initial support of the side walls of the cross passage, the side wall anchors, and the third temporary steel support at the bottom of the cross passage should be constructed in a timely manner.

[0035] Furthermore, in step xiii, after the anchor cables reach the design strength, the main body of the station is constructed by opening the gate on the side wall of the cross passage. During the initial support of the main body, before opening the gate to construct the main body of the station, the first temporary steel support and the second temporary steel support at the bottom of the cross passage within the gate area must be removed.

[0036] Furthermore, step xiv involves lining the upper part of the main structure, with the specific process as follows:

[0037] First, the upper half of the station section is constructed to a certain length;

[0038] Then, temporary support beams were erected for the main structure of the construction station;

[0039] Finally, after the temporary support beams of the main station structure met the design requirements, the upper part of the main structure was lined.

[0040] Furthermore, step xv involves constructing the main structure within the cross passageway, with the specific process as follows:

[0041] First, determine whether the lining of the upper part of the main structure has reached the design strength;

[0042] Then, according to the construction requirements, the remaining first temporary steel support at the bottom of the cross passage and the second temporary steel support at the bottom of the cross passage were removed in stages.

[0043] Next, the main structure within the construction cross passage area;

[0044] Finally, the gaps between the main structure and the initial support within the transverse passage area were backfilled.

[0045] The beneficial effects of this invention are as follows:

[0046] This invention utilizes anchor cables for the support construction of high sidewalls in large underground chambers. Compared with traditional methods, it can reduce the use of temporary steel supports and save costs. The anchor cables provide strong reaction force, which can reduce construction risks. It also reduces the number of process changes during construction, achieving the goal of rapid construction. This invention can effectively reduce project costs and has strong promotional value. Attached Figure Description

[0047] Figure 1 This is a cross-sectional view of the high sidewall support measures for the underground chamber in this invention;

[0048] Figure 2 This is a cross-sectional view (AA) of the high sidewall support measures for underground chambers in this invention;

[0049] Figure 3 This is section BB of the high sidewall support measures for underground chambers in this invention;

[0050] Figure 4 This is a diagram showing the arrangement of the end sealing of the transverse channel in this invention;

[0051] Figure 5 This is a large-scale view of node C in this invention;

[0052] in:

[0053] 010 Arch pre-support 012 Main structure pre-support

[0054] 020 Initial support for the arch; 030 Initial support for the sidewalls

[0055] 031 Rebar 032 Connecting Steel Plate

[0056] 033 Connecting bolt; 040 Side wall anchor.

[0057] 041 Anchor bolts on the lower side wall of the station; 051 First temporary steel support at the bottom of the cross passage.

[0058] 052 Second temporary steel support at the bottom of the cross passage

[0059] 053 Third temporary steel support at the bottom of the cross passage

[0060] 060 Guide wall 070 Initial support for main structure

[0061] 080 Temporary support beams for the main body of the station; 081 Lining of the upper part of the main structure.

[0062] 082 Main structure within the construction cross passageway area

[0063] 090 Station sub-lining 101 end H-beam

[0064] 102 Anchor bolt at the end of the cross passage; 110 Connecting steel bar

[0065] 120 Backfill. Detailed Implementation

[0066] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0067] like Figures 1 to 5 As shown, a method for supporting a high sidewall in a large underground chamber includes the following steps:

[0068] i. Construct the arch support 010 for the transverse passage and excavate the first layer I of the transverse passage;

[0069] ii. Anchor bolt 102 and I-beam 101 at the end of the construction cross passage;

[0070] iii. Within the first layer I of the transverse passage, set up a drilling rig, drill holes, and install the first layer of anchor cables MS1;

[0071] iv. In advance, install the main structure advance support 012 at the opening of the horse head door on the side wall of the first floor of the transverse passage, and install the guide wall 060 within the first floor range;

[0072] v. Excavate the second layer of the transverse passage (II);

[0073] vi. Anchor bolt 102 and I-beam 101 at the end of the construction cross passage;

[0074] vii. Within the second layer of the transverse passage (II), set up a drilling rig, drill holes, and install the second row of anchor cables MS2 and the third row of anchor cables MS3;

[0075] ⅷ. In advance, install the main structure advance support 012 at the opening of the horse head door on the side wall of the second floor II range of the transverse passage, and install the guide wall 060 within the second floor range;

[0076] ⅸ. Excavate the third layer (III) of the transverse passage;

[0077] x. Anchor bolt 102 and I-beam 101 at the end of the construction cross passage;

[0078] xi. Within the third layer (III) of the transverse passage, set up a drilling rig, drill holes, and install the fourth row of anchor cables MS4 and the fifth row of anchor cables MS5;

[0079] xii. Pre-install the main structure advance support 012 at the opening of the horse-head door on the side wall of the third floor (III) of the transverse passage; install the guide wall 060 within the third floor area;

[0080] ⅹⅲ. After the anchor cables reach the design strength, open the gate on the side wall of the cross passage to construct the main body of the station and promptly construct the initial support of the main body 070;

[0081] xiv. Lining of the upper half of the main structure (081);

[0082] xv. Main structure within the construction cross passage area 082;

[0083] xvi. After the upper half section lining 081 of the main structure and the main structure 082 within the transverse passage reach the design strength, continue to excavate the surrounding rock within the fifth layer V to the design height of the anchor cable, and promptly construct the side wall anchor 041 and anchor cable MS6.

[0084] xvii. Repeat step xvii until the entire underground chamber has been excavated;

[0085] ⅹⅷ. Construct the lower lining of the station 090 to effectively connect the lower lining of the station 090 with the main structure 082 within the cross passage.

[0086] Step i involves constructing the arch support 010 for the transverse passage and excavating the first layer I of the transverse passage, which also includes the following processes:

[0087] During the excavation process, the initial arch support 020, side wall anchors 040, initial side wall support 030, and the first temporary steel support 051 at the bottom of the cross passage should be constructed in a timely manner.

[0088] Step ii, the construction of the end anchor bolt 102 and the end I-beam 101 of the cross passage, also includes the following processes:

[0089] First, the end I-beams 101 are connected together with connecting steel bars 110;

[0090] Then, connect the end I-beam 101 to the initial arch support 020.

[0091] In steps ⅵ and ⅹ, during the construction of the end anchor rods 102 and end I-beams 101 of the cross passage, the end I-beams 101 are connected together by connecting steel bars 110.

[0092] Step v, excavating the second layer II of the transverse passage, also includes the following processes:

[0093] During the excavation process, the initial support 030 for the side walls of the transverse passage, the side wall anchors 040, and the second temporary steel support 052 at the bottom of the transverse passage were constructed in a timely manner.

[0094] Step ⅷ: In advance, install the main structure advance support 012 at the opening of the horse head door on the side wall of the second layer II range of the transverse passage. In the guide wall within the second layer range, during the installation of the main structure advance support, in order to facilitate construction, part of the first temporary steel support 051 at the bottom of the transverse passage can be removed.

[0095] Step 8, excavating the third layer (III) of the transverse passage, also includes the following processes:

[0096] During the excavation process, the initial support for the side walls of the transverse passage (030), the side wall anchors (040), and the third temporary steel support at the bottom of the transverse passage (053) should be constructed in a timely manner.

[0097] Step IXiii: After the anchor cables reach the design strength, the main body of the station is constructed by opening the gate on the side wall of the cross passage. In the initial support of the main body 070, before opening the gate to construct the main body of the station, the first temporary steel support 051 and the second temporary steel support 052 at the bottom of the cross passage within the gate area must be removed.

[0098] Step ⅹⅳ involves constructing the upper part of the main structure lining (081). The specific process is as follows:

[0099] First, the upper half of the station section is constructed to a certain length;

[0100] Then, the temporary support beam 080 for the main body of the construction station;

[0101] Finally, after the temporary support beam 080 of the main station structure meets the design requirements, the upper part of the main structure is lined with 080.

[0102] Step XV involves constructing the main structure 082 within the cross passageway area. The specific process is as follows:

[0103] First, determine whether the 081 lining of the upper part of the main structure has reached the design strength;

[0104] Then, according to the construction requirements, the remaining temporary steel supports 051 and 052 at the bottom of the cross passage were dismantled in stages.

[0105] Next, the main structure within the construction cross passage area is 082;

[0106] Finally, the gap between the main structure 082 and the initial support within the transverse passage area was backfilled by 120.

[0107] Specifically, C15 plain concrete can be used for backfilling 120, or masonry structure can be used.

[0108] Specifically, in step IXVII, during the construction of the lower lining of the station 090, to effectively connect the lower lining of the station 090 with the main structure 082 within the cross passage, it is necessary to remove the excess third temporary steel support 053 at the bottom of the cross passage before construction.

[0109] Another embodiment

[0110] A method for supporting high sidewalls in a large underground chamber includes the following steps:

[0111] i. Construct the arch support 010 for the transverse passage and excavate the first layer I of the transverse passage;

[0112] ii. Anchor bolt 102 and I-beam 101 at the end of the construction cross passage;

[0113] iii. Within the first layer I of the transverse passage, set up a drilling rig, drill holes, and install the first layer of anchor cables MS1;

[0114] iv. In advance, install the main structure advance support 012 at the opening of the horse head door on the side wall of the first floor of the transverse passage, and install the guide wall 060 within the first floor range;

[0115] v. Excavate the second layer of the transverse passage (II);

[0116] vi. Anchor bolt 102 and I-beam 101 at the end of the construction cross passage;

[0117] vii. Within the second layer of the transverse passage (II), set up a drilling rig, drill holes, and install the second row of anchor cables MS2 and the third row of anchor cables MS3;

[0118] ⅷ. In advance, install the main structure advance support 012 at the opening of the horse head door on the side wall of the second floor II range of the transverse passage, and install the guide wall 060 within the second floor range;

[0119] ⅸ. Excavate the third layer (III) of the transverse passage;

[0120] x. Anchor bolt 102 and I-beam 101 at the end of the construction cross passage;

[0121] xi. Within the third layer (III) of the transverse passage, set up a drilling rig, drill holes, and install the fourth row of anchor cables MS4 and the fifth row of anchor cables MS5;

[0122] xii. Pre-install the main structure advance support 012 at the opening of the horse-head door on the side wall of the third floor (III) of the transverse passage; install the guide wall 060 within the third floor area;

[0123] ⅹⅲ. After the anchor cables reach the design strength, open the gate on the side wall of the cross passage to construct the main body of the station and promptly construct the initial support of the main body 070;

[0124] xiv. Lining of the upper half of the main structure (081);

[0125] xv. Main structure within the construction cross passage area 082;

[0126] xvi. After the upper half section lining 081 of the main structure and the main structure 082 within the transverse passage reach the design strength, continue to excavate the surrounding rock within the fifth layer V to the design height of the anchor cable, and promptly construct the side wall anchor 041 and anchor cable MS6.

[0127] xvii. Repeat step xvii until the entire underground chamber has been excavated;

[0128] ⅹⅷ. Construct the lower lining of the station 090 to effectively connect the lower lining of the station 090 with the main structure 082 within the cross passage.

[0129] Step i involves constructing the arch support 010 for the transverse passage and excavating the first layer I of the transverse passage, which also includes the following processes:

[0130] During the excavation process, the initial arch support 020, side wall anchors 040, initial side wall support 030, and the first temporary steel support 051 at the bottom of the cross passage should be constructed in a timely manner.

[0131] Step ii, the construction of the end anchor bolt 102 and the end I-beam 101 of the cross passage, also includes the following processes:

[0132] First, the end I-beams 101 are connected together with connecting steel bars 110;

[0133] Then, connect the end I-beam 101 to the initial arch support 020.

[0134] In steps ⅵ and ⅹ, during the construction of the end anchor rods 102 and end I-beams 101 of the cross passage, the end I-beams 101 are connected together by connecting steel bars 110.

[0135] Step v, excavating the second layer II of the transverse passage, also includes the following processes:

[0136] During the excavation process, the initial support 030 for the side walls of the transverse passage, the side wall anchors 040, and the second temporary steel support 052 at the bottom of the transverse passage were constructed in a timely manner.

[0137] Step ⅷ: In advance, install the main structure advance support 012 at the opening of the horse head door on the side wall of the second layer II range of the transverse passage. In the guide wall within the second layer range, during the installation of the main structure advance support, in order to facilitate construction, part of the first temporary steel support 051 at the bottom of the transverse passage can be removed.

[0138] Step 8, excavating the third layer (III) of the transverse passage, also includes the following processes:

[0139] During the excavation process, the initial support for the side walls of the transverse passage (030), the side wall anchors (040), and the third temporary steel support at the bottom of the transverse passage (053) should be constructed in a timely manner.

[0140] Step IXiii: After the anchor cables reach the design strength, the main body of the station is constructed by opening the gate on the side wall of the cross passage. In the initial support of the main body 070, before opening the gate to construct the main body of the station, the first temporary steel support 051 and the second temporary steel support 052 at the bottom of the cross passage within the gate area must be removed.

[0141] Step ⅹⅳ involves constructing the upper part of the main structure lining (081). The specific process is as follows:

[0142] First, the upper half of the station section is constructed to a certain length;

[0143] Then, the temporary support beam 080 for the main body of the construction station;

[0144] Finally, after the temporary support beam 080 of the main station structure meets the design requirements, the upper part of the main structure is lined with 080.

[0145] Step XV involves constructing the main structure 082 within the cross passageway area. The specific process is as follows:

[0146] First, determine whether the 081 lining of the upper part of the main structure has reached the design strength;

[0147] Then, according to the construction requirements, the remaining temporary steel supports 051 and 052 at the bottom of the cross passage were dismantled in stages.

[0148] Next, the main structure within the construction cross passage area is 082;

[0149] Finally, the gap between the main structure 082 and the initial support within the transverse passage area was backfilled by 120.

[0150] Specifically, C15 plain concrete can be used for backfilling 120, or masonry structure can be used.

[0151] Specifically, in step IXVII, during the construction of the lower lining of the station 090, to effectively connect the lower lining of the station 090 with the main structure 082 within the cross passage, it is necessary to remove the excess third temporary steel support 053 at the bottom of the cross passage before construction.

[0152] In this embodiment, the arch pre-support 010 uses φ42 small guide pipes with a circumferential spacing of 0.3-0.4m and L=3.0-4.0m. In this embodiment, the circumferential spacing is 0.4m and L=3.0m. The excavation adopts the full-section excavation method or the step excavation method according to the cross-sectional dimensions. In this embodiment, the step excavation method is adopted, and the step spacing is staggered by 3-5m. Each step adopts a 1:(0.3-1.0) slope according to the soil stability.

[0153] Initial arch support 020, details are as follows:

[0154] ① φ8 double-layer steel mesh, spacing 200mm x 200mm;

[0155] ② The spacing between the steel grid frames is 500mm;

[0156] ③ C25 shotcrete, 350mm thick, impermeability grade P6.

[0157] Initial support for the side wall 030, as detailed below:

[0158] ① φ8 double-layer steel mesh, spacing 200mm x 200mm;

[0159] ② The spacing between the steel grid frames is 500mm. A steel plate needs to be reserved at the connection between the grid and the temporary support at the bottom to facilitate later connection.

[0160] ③ C25 shotcrete, thickness same as arch.

[0161] The side wall anchor 040 is a φ25 mortar anchor with L=3.0m and a spacing (vertical x longitudinal) of 1.5m x 1.0m.

[0162] The first temporary steel support 051, the second temporary steel support 052, and the third temporary steel support 053 at the bottom of the cross passage are I25b type steel supports, filled with 300mm thick C25 concrete.

[0163] Specifically, the first temporary steel support 051, the second temporary steel support 052, and the third temporary steel support 053 at the bottom of the transverse passage within the main structure area will not be filled with concrete to facilitate later excavation.

[0164] Specifically, the first temporary steel support 051, the second temporary steel support 052, and the third temporary steel support 053 at the bottom of the transverse passage are effectively connected to the side wall grid to meet the overall stress requirements.

[0165] The connecting steel bars 110 are made of Φ20 threaded steel with a spacing of 500mm.

[0166] The end H-beams 101 are I-16a, with a spacing of 1.0m.

[0167] The end I-beam 101 is connected to the side wall of the connecting steel plate 032, and the connecting steel plate 032 is connected to the grid reinforcement 031 by connecting bolts 033.

[0168] The main structure advanced support 012 is installed at the opening of the horse head door on the side wall. The main structure advanced support 012 is effectively welded to the side wall grid to meet the overall stress requirements.

[0169] Specifically, the main structure can be excavated using the CD method or the double-side-wall pilot tunnel method. In this embodiment, the double-side-wall pilot tunnel method is used.

[0170] Specifically, the installation of anchor cables can be carried out simultaneously with the installation of the pre-support 012 of the main structure; or it can be carried out simultaneously after the installation of the pre-support 012 of the main structure is completed, and the next layer of excavation can only be carried out after the anchor cables are tensioned.

[0171] Specifically, the first temporary steel support 051, the second temporary steel support 052, and the third temporary steel support 053 at the bottom of the cross passage should be dismantled, and tunnel monitoring should be strengthened during the process. When constructing the station main structure by opening the gate on the side wall of the cross passage, a grid steel frame should be erected at the cut-off section of the passage grid steel frame and reinforced and welded to the cut-off passage grid. After entering the station main structure, the three grid frames initially erected should be connected and erected together.

[0172] Specifically, when continuing to excavate the surrounding rock downwards, the design layer thickness should be strictly followed. Upon reaching the design height, initial support and anchor cables should be installed promptly. Excavation of the next layer can only proceed after the anchor cables have been tensioned and meet design requirements. Furthermore, excavation can be carried out simultaneously with the excavation within the main structure to improve construction efficiency.

[0173] Backfilling to 120mm can be done with C15 plain concrete or masonry. When backfilling, attention should be paid to the height of each layer, and a waterproof layer should be properly laid.

[0174] This invention utilizes anchor cables for the support construction of high sidewalls in large underground chambers. Compared with traditional methods, it can reduce the use of temporary steel supports and save costs. The anchor cables provide strong reaction force, which can reduce construction risks. It also reduces the number of process changes during construction, achieving the goal of rapid construction. This invention can effectively reduce project costs and has strong promotional value.

Claims

1. A method for supporting high sidewalls in a large underground chamber, characterized in that: Includes the following steps: (i) Construct the arch support for the transverse passage and excavate the first layer I of the transverse passage; (ii) Anchor bolts and I-beams at the ends of the construction cross passage; (iii) Within the first layer I of the transverse passage, set up a drilling rig, drill holes, and install the first layer of anchor cables MS1; (iv) Pre-install the main structure support at the horse-head door opening on the side wall of the first floor of the transverse passage, and install the guide wall within the first floor range; (v) Excavate the second layer of the transverse passage, II; (vi) Anchor bolts and I-beams at the ends of the construction cross passage; (vii) Within the second layer of the transverse passage, set up a drilling rig, drill holes, and install the second row of anchor cables MS2 and the third row of anchor cables MS3; (ⅷ) Pre-install the main structure support at the horse-head door opening on the side wall of the second floor II range of the transverse passage, and install the guide wall within the second floor range; (eight) Excavate the third layer of the transverse passage (III); (x) Anchor bolts and I-beams at the ends of the construction cross passage; (xi) Within the third layer (III) of the transverse passage, set up a drilling rig, drill holes, and install the fourth row of anchor cables MS4 and the fifth row of anchor cables MS5; (xii) Pre-install the main structure's pre-support at the horse-head door opening on the side wall of the third floor (III) of the transverse passage; install the guide wall within the third floor area; (xiii) After the anchor cables reach the design strength, the main body of the station will be constructed by opening the gate on the side wall of the cross passage and the initial support of the main body will be constructed in a timely manner. (xiv) Lining of the upper half of the main structure; (xv) Main structure within the construction cross passageway area; (xvii) After the upper half section lining of the main structure and the main structure within the transverse passage reach the design strength, continue to excavate the surrounding rock within the fifth layer V to the design height of the anchor cable, and promptly construct the side wall anchors and anchor cables MS6. (xvii) Repeat step (xvii) until the entire underground chamber has been excavated; (xiii) Construct the lower lining of the station to effectively connect the lower lining of the station with the main structure within the cross passage.

2. The method for supporting a high sidewall in a large underground chamber according to claim 1, characterized in that: Step (i) involves constructing the arch support for the transverse passage and excavating the first layer (I) of the transverse passage, which also includes the following processes: During the excavation process, it is necessary to promptly construct the initial support of the transverse arch, the side wall anchors, the initial support of the side walls, and the first temporary steel support at the bottom of the transverse passage.

3. The method for supporting a high sidewall in a large underground chamber according to claim 1, characterized in that: Step (ii) of constructing the end anchor bolts and end I-beams of the cross passage also includes the following processes: First, the end I-beams are connected together with reinforcing bars; Then, the end I-beams are connected to the initial support of the arch.

4. The method for supporting a high sidewall in a large underground chamber according to claim 1, characterized in that: In steps (vi) and (x), the end anchors and end I-beams of the construction cross passage are connected together with connecting steel bars.

5. The method for supporting a high sidewall in a large underground chamber according to claim 2, characterized in that: Step (v) Excavating the second layer II of the transverse passage also includes the following processes: During the excavation process, the initial support of the side walls of the cross passage, the side wall anchors, and the second temporary steel support at the bottom of the cross passage were constructed in a timely manner.

6. The method for supporting a high sidewall in a large underground chamber according to claim 2, characterized in that: Step (ⅷ) In advance, install the main structure advance support at the horse-head door opening on the side wall of the second layer II range of the transverse passage, and install the guide wall in the second layer range. When installing the main structure advance support, in order to facilitate construction, part of the first temporary steel support at the bottom of the transverse passage can be removed.

7. The method for supporting a high sidewall in a large underground chamber according to claim 5, characterized in that: Step (ⅸ) Excavating the third layer (III) of the transverse passage also includes the following processes: During the excavation process, the initial support of the side walls of the cross passage, the side wall anchors, and the third temporary steel support at the bottom of the cross passage should be constructed in a timely manner.

8. A method for supporting a high sidewall in a large underground chamber according to claim 7, characterized in that: Step (xiii) After the anchor cable reaches the design strength, the main body of the station is constructed by opening the gate on the side wall of the cross passage. In the initial support of the main body, before opening the gate to construct the main body of the station, the first temporary steel support and the second temporary steel support at the bottom of the cross passage within the gate area must be removed.

9. A method for supporting a high sidewall in a large underground chamber according to claim 1, characterized in that: Step (xiv) involves lining the upper part of the main structure. The specific process is as follows: First, the upper half of the station section is constructed to a certain length; Then, temporary support beams were erected for the main structure of the construction station; Finally, after the temporary support beams of the main station structure met the design requirements, the upper part of the main structure was lined.

10. A method for supporting a high sidewall in a large underground chamber according to claim 1, characterized in that: Step (xv) involves constructing the main structure within the cross passageway area. The specific process is as follows: First, determine whether the lining of the upper part of the main structure has reached the design strength; Then, according to the construction requirements, the remaining first temporary steel support at the bottom of the cross passage and the second temporary steel support at the bottom of the cross passage were removed in stages. Next, the main structure within the construction cross passage area; Finally, the gaps between the main structure and the initial support within the transverse passage area were backfilled.

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