Tunnel collapse rapid treatment method using assembled self-adaptive expansion balloon stent

Abstract

The present application relates to a tunnel collapse rapid processing method using an assembled adaptive inflatable bag support, comprising reinforcing the non-collapsed section around the tunnel collapse, measuring the height and volume of each region of the tunnel collapse cavity, determining the required number of supports and support installation positions, then installing the supports and inflatable bags, performing two-stage hole making and chemical grouting in the reinforced section, forming a grout stopping layer and a consolidation layer below the collapsed broken body, removing the inflatable bags and supports, building a steel arch below the grout stopping layer, arranging a pipe shed between the steel arch below the grout stopping layer and the steel arch of the reinforced section and spraying rapid-setting concrete, so that the inside of the tunnel is separated from the cavity to form a protective shell, and secondary lining reinforcement is performed, and finally, holes are made in the reinforced section to the inside of the cavity and backfilled. The present application uses an assembled adaptive inflatable bag and support to quickly process the tunnel collapse, which can block the continuous intrusion of the collapsed body in the cavity into the construction space, preventing the slow cleaning work from reducing the construction efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tunnel construction and relates to a tunnel collapse rapid treatment method using an assembled self-adaptive inflatable bag support. BACKGROUND

[0002] In the modern underground engineering, some fault fracture zones will inevitably be encountered, and in the process of crossing them, due to subjective judgment of construction personnel, non-standard operation of equipment, and difficult to completely master geological conditions and other factors, safety problems such as collapse and the resulting water gushing and leakage are extremely easy to occur. If relevant staff cannot quickly and effectively handle it, it will lead to reduced construction efficiency and delayed project progress.

[0003] In the subsequent construction of the collapse, a temporary support is generally established by using a steel arch support and a greenhouse protection, and the cleaning work is carried out after the adjacent section is stabilized. However, in the case that the collapse body continuously invades the tunnel, if it cannot be effectively prevented, the construction period will be greatly prolonged, and the fixed type support cannot adapt to the cavities of different shapes.

[0004] By using the traditional cement-based grouting material to treat the fracture zone, although the cost is low, the durability and corrosion resistance are poor, and the improved cement-based material also often has too many modifiers and too little cement, resulting in high cost. At the same time, the cement slurry has a long solidification time, and due to its high viscosity, it has poor flowability and permeability, and cannot timely and efficiently treat the fault fracture zone. In addition, cement grouting cannot completely solve the problem of water seepage caused by concrete structure cracks. In order to solve this problem, in recent years, someone has proposed the concept of air bag grouting, for example, the Chinese invention patent with publication number CN117780392B disclosed on March 29, 2024 discloses an air bag grouting treatment method for underground excavation tunnel collapse. Although this method solves the problem of secondary collapse during construction, it assumes that the tunnel is completely buried after the collapse and does not consider other situations. In addition, the air bag structure disclosed in this method is simple and single, and cannot well fit and close the irregular cavity. At the same time, it does not consider the possibility of sudden failure of the structure during construction, which reduces the safety of the construction space below the cavity. Therefore, it is urgent to develop a method that can quickly protect the tunnel space from continuous invasion of the collapse body and efficiently treat the broken body. SUMMARY

[0005] The purpose of the present application is to provide a tunnel collapse rapid treatment method using an assembled self-adaptive inflatable bag support, which solves the problem of slow construction and low cement grouting efficiency caused by continuous invasion of the collapse body into the tunnel after the tunnel construction collapse.

[0006] The technical solution adopted by the present application is a tunnel collapse rapid treatment method using an assembled self-adaptive inflatable bag support, comprising the following steps:

[0007] Step 1: Reinforce the uncollapsed area around the tunnel collapse, and determine whether water gushing occurs at the tunnel collapse site. If water gushing occurs, drain the tunnel and then proceed to step 2. If water gushing does not occur, proceed directly to step 2.

[0008] Step 2: measuring the height and volume of each area of ​​the tunnel collapse cavity;

[0009] Step 3: Determine the required number of pillars and their installation locations based on the height and volume of each area of ​​the tunnel collapse cavity. Perform the first stage of slag removal on the tunnel collapse cavity, then install the pillars and expansion bladders. Fill the expansion bladders with water in different areas to ensure they fit tightly against the rock wall in the cavity.

[0010] Step 4: Perform two-stage pore drilling and chemical grouting in the reinforced area to form a grouted rock mass below the collapsed body, the grouted rock mass including a grouting layer and a consolidation layer;

[0011] Step 5: Release the contents of the expansion bladder, conduct the second stage of slag removal in the tunnel, and then remove the expansion bladder and support pillars;

[0012] Step 6: Build a steel arch frame under the rock mass after grouting, arrange a pipe shed and lay a steel mesh between the steel arch frame under the rock mass after grouting and the steel arch frame in the reinforced section, then spray quick-setting concrete to separate the inside of the tunnel from the cavity to form a protective shell, and carry out secondary lining reinforcement. Finally, make holes into the cavity in the reinforced section and backfill.

[0013] In step 1, the uncollapsed section around the tunnel collapse is reinforced, including adding locking anchor rods on both sides of the steel arch frame in the uncollapsed section around the tunnel collapse, and welding the gaskets of the locking anchor rods to the arch frame.

[0014] In step 2, a three-dimensional laser scanner is used to scan the tunnel collapse cavity to construct a three-dimensional model of the tunnel collapse cavity, thereby obtaining the height and volume of each area of ​​the cavity.

[0015] The specific process of step 3 is as follows:

[0016] Step 3.1: Calculate the impact force of the debris from the top of the tunnel collapse cavity falling to the top of the support F 1:

[0017]

[0018]

[0019]

[0020] Where, M is the weight of the gravel at the top of the tunnel collapse cavity, M= pV , pD is the density of the rock mass on the top of the tunnel, V is the volume of the cavity of the tunnel collapse, is the maximum falling velocity of the rock on the top of the cavity of the tunnel collapse, is the time for the rock on the top of the cavity of the tunnel collapse to fall to the top of the support, is the time for the rock to contact the support, H is the average height difference from the top of the cavity of the tunnel collapse to the top of the support, and the height of the support is the height of the top of the excavated chamber;

[0021] Step 3.2, the cavity of the tunnel collapse is evenly divided into n regions along the length direction of the tunnel, and the volume of each region is , and the number of supports (1) required for each region is , and the calculation formula is as follows:

[0022]

[0023] In the formula, F 1 is the impact force of the rock on the top of the cavity of the tunnel collapse falling to the top of the support, F 2 is the bearing capacity of a single support, and W1 is the maximum gravity of the expanded capsule after water injection;

[0024] If the calculated is a decimal number, the rounding method is used to round it;

[0025] Step 3.3, it is judged whether the number of supports required by each region after rounding is greater than 1, and the region with > 1 is divided again along the width direction of the tunnel into N regions, and the volume of each region is X j , X j = X 1, X 2, …, X N , and the number of supports required for each region is , and the calculation formula is as follows:

[0026]

[0027] If the calculated is a decimal number, the rounding method is used to round it;

[0028] Step 3.4, it is judged whether the number of supports required by each region after rounding is greater than 1, and the region with > 1 is divided again until the number of supports allocated to each region is 1;

[0029] Step 3.5, select the support installation position in each area, carry out the first stage of slag removal on the support installation position, remove the collapsed body, and then install the support. After the support is installed, use the steel bar to connect each other;

[0030] Step 3.6, install the expansion bag at the top of the support, and carry out partition water filling on the expansion bag to make the expansion bag closely adhere to the cavity wall;

[0031] Step 3.7, adjust the height of the support to make the top of each support adhere to the bottom of the expansion bag.

[0032] The support is a hydraulic support, the bottom of the support is provided with a square base, a ground nail hole is formed around the square base, four rotating parts are sleeved near the top of the support, the rotating parts are rotatably connected with the support, and a steel bar hole is formed in the side surface of the rotating part.

[0033] The expansion bag is a multi-cavity expansion bag, each cavity is independent of each other and has a water inlet and a sealing plug.

[0034] The specific process of step 4 is as follows:

[0035] Step 4.1, use a hand drill to drill a first stage hole in the reinforced section, the drill rod is a hollow self-advancing anchor rod, the hole is formed at one time, a connecting sleeve is used to connect the rods, the anchor rod is left in the rock body, and after the drill hole is communicated with the top broken body of the expansion bag, a first stage grouting hole is formed, and a 10cm-30cm joint is reserved;

[0036] Step 4.2, flush the impurities in the first stage grouting hole with pressure water, use a seamless steel pipe to segmentally plug into the self-advancing anchor rod, weld the joint, and use high-pressure air to blow to ensure that there is no rock slag in the steel pipe, then weld a joint at the tail end of the seamless steel pipe, and connect it with the grouting pump pipeline;

[0037] Step 4.3, when grouting, the first time of preparing the slurry does not exceed 15kg, the slurry preparation barrel is placed in a cooling water tank to prepare the slurry, the proportion of each component is modified epoxy resin grouting liquid: curing agent: curing accelerator = 1000:70:10, artificial stirring is used to mix each component uniformly, and then the slurry is injected into the seamless steel pipe through the grouting pump to form an arch-shaped structure of the grout stopping layer in the tunnel collapse broken body;

[0038] Step 4.4, cut off the reserved anchor rod joint, close the grouting hole, and manually seal the hole with cement mortar mixed with an expanding agent, the expanding agent accounts for 3%-3.5% of the amount of cement.

[0039] Step 4.5, use a hand drill to drill a second stage hole in the reinforced section, and after the drill hole is communicated with the top broken body of the grout stopping layer, a second stage grouting hole is formed, and a 10cm-30cm joint is reserved;

[0040] Step 4.6, inject slurry through the second stage grouting hole to form an arch-shaped structure consolidated layer above the grouting stop layer, cut off the reserved anchor rod joint, close the grouting hole, and manually seal the empty section in the hole with cement mortar mixed with an expanding agent.

[0041] An arch-shaped structure grouting stop layer is formed in the tunnel collapse broken body, the grouting pressure is 6-8MPa, and an arch-shaped structure consolidated layer is formed above the grouting stop layer, and the grouting pressure is 12-13MPa.

[0042] In step 6, a steel arch is erected below the rock mass after grouting, and the spacing between the steel arches is determined according to the surrounding rock grade of the construction area, that is, the spacing between the steel arches is 120cm for surrounding rock of grade III and above, the spacing between the steel arches is 100cm for surrounding rock between type II and type III, and the spacing between the steel arches is 50cm-80cm for surrounding rock below type II.

[0043] In step 6, holes are drilled into the cavity inside the reinforced section and backfilled, and the specific process is as follows:

[0044] Step 6.1, drill holes into the cavity inside the reinforced section of step 1 to the bottom of the grouting stop layer and set backfill grouting pipes, so that the holes are inclined upward, different grouting pipe heights are achieved on one side of the cavity outlet according to different hole angles, and exhaust holes and exhaust pipes are arranged near the top of the cavity;

[0045] Step 6.2, partially layer grouting is carried out in the cavity through different height grouting pipes, the grouting pressure value is 0.3MPa, the grouting height of each time does not exceed 1m, until the grouting hole stops absorbing slurry, and the grouting can be ended after 5min of continuous grouting, and the grouting of all grouting holes is completed;

[0046] Step 6.3, remove the dirt in the grouting hole and the exhaust hole, seal and smooth the whole hole with cement mortar, and cut off the embedded pipe exposed on the surface of the lining concrete.

[0047] The beneficial effects of the present application are as follows:

[0048] (1) The assembled self-adaptive expansion bag and support are used for rapid treatment of the tunnel collapse, which can block the continuous intrusion of the collapse body in the cavity into the construction space, and prevent the reduction of construction efficiency caused by slow cleaning work;

[0049] (2) The support sleeve used in the present application is provided with four rotating parts, the rotating parts are rotationally connected with the support, steel holes are formed in the side surface of the rotating part, a plurality of supports can be connected in any triangular shape, the space occupied by a single support base is small, so the support can be placed at a small part of the position which does not need to be cleaned or is easy to clean, and a large area of work platform is not needed, thereby reducing the possibility of further intrusion of the collapse body in the cavity into the tunnel due to the long cleaning period;

[0050] (3) For the cavity with different shapes after the collapse, the hydraulic prop can adjust the placement position and height, so as to realize higher adaptability, and the expansion bag is a multi-cavity expansion bag, each cavity is independent, the appropriate partition can be selected according to the shape of the tunnel collapse cavity to expand, so that the expansion bag can be as close as possible to the rock wall, and the plugging efficiency is improved;

[0051] (4) According to the height and volume of each region of the cavity, the number of required props is determined, and then the prop installation position is distributed, the prop density of the region with large falling impact force is increased, the prop density of the region with small impact force is reduced, the ability of the prop structure to withstand accidental load in different regions is adjusted, and the ability of the prop structure to withstand accidental load in different regions is adjusted.

[0052] (5) Compared with the traditional cement grouting treatment, the layered chemical grouting used in the present application has the advantages of good durability and corrosion resistance, fast consolidation effect and less material waste. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 is a flowchart of the tunnel collapse rapid treatment method using the assembled self-adaptive expansion bag support of the present application;

[0054] Figure 2 is a schematic view of the prop structure in the tunnel collapse rapid treatment method using the assembled self-adaptive expansion bag support of the present application;

[0055] Figure 3 is a schematic view of the prop installation position determination process in the tunnel collapse rapid treatment method using the assembled self-adaptive expansion bag support of the present application;

[0056] Figure 4 is a structural view of the expansion bag used in embodiment 2 of the present application;

[0057] Figure 5 is a schematic view of two-stage pore forming and chemical grouting in the tunnel collapse rapid treatment method using the assembled self-adaptive expansion bag support of the present application;

[0058] Figure 6 is a schematic view of the steel arch installation in the tunnel collapse rapid treatment method using the assembled self-adaptive expansion bag support of the present application.

[0059] In the figure, 1. prop, 2. broken body, 3. collapsed body, 4. steel arch, 5. expansion bag, 6. first stage grouting hole, 7. second stage grouting hole, 8. grout stopping layer, 9. consolidation layer, 10. tunnel collapse cavity, 11. pipe shed, 12. steel mesh, 13. rock mass after grouting, 14. steel bar, 15. square base, 16. rotating part, 17. ground nail hole, 18. steel bar hole. DETAILED DESCRIPTION

[0060] The application will be described in detail below with reference to the drawings and specific embodiments.

[0061] Embodiment 1

[0062] A tunnel collapse rapid treatment method using an assembled adaptive inflatable bag support, referring to Figure 1 , comprising the following steps:

[0063] Step 1, reinforcing the non-collapsed section around the tunnel collapse, determining whether water gushing occurs at the tunnel collapse, if water gushing occurs, carrying out tunnel drainage, then carrying out step 2, if water gushing does not occur, directly carrying out step 2;

[0064] Step 2, measuring the height and volume of each region of the tunnel collapse cavity 10;

[0065] Step 3, determining the number and installation position of the required support 1 according to the height and volume of each region of the tunnel collapse cavity 10, carrying out the first stage of slag removal on the tunnel collapse cavity 10, then installing the support 1 and the inflatable bag 5, and carrying out partitioned water filling on the inflatable bag 5 to make the inflatable bag 5 closely adhere to the cavity wall;

[0066] Step 4, carrying out two-stage hole making and chemical grouting in the reinforced section to form a grouted rock mass 13 under the collapsed broken body 2, the grouted rock mass 13 including a grout stopping layer 8 and a consolidation layer 9;

[0067] Step 5, releasing the internal material of the inflatable bag 5, carrying out the second stage of slag removal in the tunnel, then removing the inflatable bag 5 and the support 1;

[0068] Step 6, building a steel arch 4 under the grouted rock mass 13, arranging a pipe shed 11 between the steel arch under the grouted rock mass and the steel arch of the reinforced section and laying a steel mesh 12, then spraying rapid-setting concrete to form a protective shell by separating the inside of the tunnel from the cavity, and carrying out secondary lining reinforcement, and finally making holes into the cavity and backfilling in the reinforced section.

[0069] Embodiment 2

[0070] A tunnel collapse rapid treatment method using an assembled adaptive inflatable bag support, comprising the following steps:

[0071] Step 1, reinforcing the non-collapsed section around the tunnel collapse, including applying locking anchor rods on both sides of the steel arch in the non-collapsed section around the tunnel collapse, and welding and fixing the gaskets of the locking anchor rods to the arch, then determining whether water gushing occurs at the tunnel collapse, if water gushing occurs, carrying out tunnel drainage, then carrying out step 2, if water gushing does not occur, directly carrying out step 2;

[0072] Step 2, measure the height and volume of each region of the tunnel collapse cavity 10, scan the tunnel collapse cavity using a three-dimensional laser scanner, construct a three-dimensional model of the tunnel collapse cavity, and obtain the height and volume of each region of the cavity;

[0073] Step 3, determine the number and installation position of the required support 1 according to the height and volume of each region of the tunnel collapse cavity 10, perform the first stage of slag removal on the tunnel collapse cavity 10, then install the support 1 and the expansion bag 5, and perform partitioned water filling on the expansion bag 5 to make the expansion bag 5 closely fit the rock wall in the cavity;

[0074] Step 4, perform two-stage hole making and chemical grouting in the reinforced section to form a grouted rock mass 13 under the broken body 2 of the collapse, the grouted rock mass 13 including a grout stopping layer 8 and a consolidation layer 9;

[0075] Step 5, release the internal material of the expansion bag 5, perform the second stage of slag removal in the tunnel, then remove the expansion bag 5 and the support 1;

[0076] Step 6, build a steel arch 4 under the grouted rock mass 13, arrange a pipe shed 11 between the steel arch under the grouted rock mass and the steel arch of the reinforced section and lay a steel mesh 12, then spray rapid-setting concrete to separate the inside of the tunnel from the cavity to form a protective shell, perform secondary lining reinforcement, and finally make holes in the cavity and perform backfilling in the reinforced section.

[0077] Example 3

[0078] A tunnel collapse rapid processing method using a fabricated self-adaptive expansion bag support, comprising the following steps:

[0079] Step 1, reinforce the non-collapsed section around the tunnel collapse, including applying locking anchor rods on both sides of the steel arch in the non-collapsed section around the tunnel collapse, and welding and fixing the gaskets of the locking anchor rods to the arch, then determining whether water gushing occurs at the tunnel collapse, if water gushing occurs, draining the water in the tunnel, then performing step 2, if no water gushing occurs, directly performing step 2;

[0080] Step 2, measure the height and volume of each region of the tunnel collapse cavity 10, scan the tunnel collapse cavity using a three-dimensional laser scanner, construct a three-dimensional model of the tunnel collapse cavity, and obtain the height and volume of each region of the cavity;

[0081] Step 3, determine the number and installation position of the required support 1 according to the height and volume of each region of the tunnel collapse cavity 10, perform the first stage of slag removal on the tunnel collapse cavity 10, then install the support 1 and the expansion bag 5, and perform partitioned water filling on the expansion bag 5 to make the expansion bag 5 closely fit the rock wall in the cavity;

[0082] The specific process of step 3 is as follows:

[0083] Step 3.1, calculate the impact force of the tunnel collapse cavity 10 top rubble falling to the top of the pillar 1 F 1:

[0084]

[0085]

[0086]

[0087] In the formula, M is the weight of the tunnel collapse cavity top rubble, M= pV , p is the density of the tunnel top rock mass, V is the volume of the tunnel collapse cavity, is the maximum falling speed of the tunnel collapse cavity top rubble, is the time of the tunnel collapse cavity top rubble falling to the top of the pillar, is the time of the rubble contacting the pillar, H is the average height difference from the top of the tunnel collapse cavity to the top of the pillar, and the pillar height is the height of the excavated chamber top;

[0088] Step 3.2, divide the tunnel collapse cavity 10 into n regions along the length direction of the tunnel, and the cavity volume of each region is , , the number of pillars (1) required by each region is , and the calculation formula is as follows:

[0089]

[0090] In the formula, F 1 is the impact force of the tunnel collapse cavity top rubble falling to the top of the pillar, F 2 is the bearing capacity of a single pillar, and W1 is the maximum gravity of the expanded capsule after water injection;

[0091] If the calculated is a decimal number, use the rounding method to round it;

[0092] Step 3.3, determine whether the number of pillars required by each region after rounding is greater than 1, and if the region > 1, divide it again along the width direction of the tunnel into N regions, and the cavity volume of each region is X j , X j = X 1, X 2, …, X N , the number of pillars required by each region is , and the calculation formula is as follows:

[0093]

[0094] If the calculated is a decimal, use the rounding method to take 1;

[0095] Step 3.4, judge the number of required support in each region after rounding If it is greater than 1, the region with > 1 is divided again until the number of support allocated in each region is 1;

[0096] Step 3.5, select the support 1 installation position in each region, carry out the first stage of slag removal on the support installation position, remove the collapsed body 3, then install the support, and use the steel bar 14 to connect each other after the support is installed;

[0097] Step 3.6, install the expansion bag 5 at the top of the support 1, and carry out zoned water filling on the expansion bag 5 to make the expansion bag 5 closely adhere to the cavity wall;

[0098] Step 3.7, adjust the height of the support 1 to make the top of each support 1 adhere to the bottom of the expansion bag 5.

[0099] Referring to Figure 2 , the support 1 used in step 3 is a hydraulic support, the bottom of the support 1 is provided with a square base 15, the square base 15 is provided with a ground nail hole 17 around, a rotating part 16 is sleeved near the top of the support 1, the rotating part 16 is rotatably connected with the support 1, and a steel bar hole 18 is formed in the side surface of the rotating part 16.

[0100] Step 4, two-stage hole making and chemical grouting are carried out in the reinforced section to form a grouted rock mass 13 under the collapsed body 2, and the grouted rock mass 13 includes a grouting stop layer 8 and a consolidation layer 9;

[0101] Step 5, release the internal material of the expansion bag 5, carry out the second stage of slag removal in the tunnel, then remove the expansion bag 5 and the support 1;

[0102] Step 6, build a steel arch 4 under the grouted rock mass 13, arrange a pipe shed 11 between the steel arch under the grouted rock mass and the steel arch in the reinforced section and lay a steel bar net 12, then spray quick-setting concrete to separate the inside of the tunnel from the cavity to form a protective shell, and carry out secondary lining reinforcement, and finally drill holes into the cavity inside the reinforced section and backfill.

[0103] Example 4

[0104] A tunnel collapse rapid processing method using a fabricated self-adaptive expansion bag support, comprising the following steps:

[0105] Step 1, reinforcing the non-collapsed section around the tunnel collapse, including adding locking anchor rods on both sides of the steel arch frame in the non-collapsed section around the tunnel collapse, and welding and fixing the gaskets of the locking anchor rods to the arch frame, then judging whether water gushing occurs at the tunnel collapse, if water gushing occurs, then draining the tunnel, then proceeding to step 2, if no water gushing occurs, directly proceeding to step 2;

[0106] Step 2, measuring the height and volume of each region of the tunnel collapse cavity 10, scanning the tunnel collapse cavity using a three-dimensional laser scanner, and constructing a three-dimensional model of the tunnel collapse cavity, i.e. obtaining the height and volume of each region of the cavity;

[0107] Step 3, determining the number and installation position of the required support 1 according to the height and volume of each region of the tunnel collapse cavity 10, performing the first stage of slag removal on the tunnel collapse cavity 10, then installing the support 1 and the expansion bag 5, and partitioning the expansion bag 5 for water filling to make the expansion bag 5 closely fit the cavity wall;

[0108] The specific process of step 3 is as follows:

[0109] Step 3.1, calculating the impact force of the tunnel collapse cavity 10 top rubble falling to the top of the support 1 F 1:

[0110]

[0111]

[0112]

[0113] In the formula, M is the weight of the tunnel collapse cavity top rubble, M= pV , p is the density of the tunnel top rock mass, V is the volume of the tunnel collapse cavity, is the maximum falling speed of the tunnel collapse cavity top rubble, is the time for the tunnel collapse cavity top rubble to fall to the top of the support, is the time for the rubble to contact the support, H is the average height difference from the top of the tunnel collapse cavity to the top of the support, and the support height is the height of the excavated chamber top;

[0114] Step 3.2, dividing the tunnel collapse cavity 10 into n regions along the length direction of the tunnel, and the corresponding cavity volume of each region is , , the number of required supports 1 for each region is , and the calculation formula is as follows:

[0115]

[0116] In the formula, F1 is the impact force of the tunnel collapse cavity top rubble falling to the top of the support, F 2 is the bearing capacity of a single support, W1 is the maximum gravity of the expanded bag after water injection;

[0117] If the calculated is a decimal, use the rounding method to round it up;

[0118] Step 3.3, judge whether the number of supports required by each region after rounding is greater than 1, if the region is greater than 1, divide it again along the width direction of the tunnel into N regions, and the corresponding cavity volume of each region is j , X j ={ X 1, X 2, …, X N}, the number of supports required by each region is X , the calculation formula is as follows:

[0119]

[0120] If the calculated is a decimal, use the rounding method to round it up;

[0121] Step 3.4, judge whether the number of supports required by each region after rounding is greater than 1, if the region is greater than 1, divide it again along the width direction of the tunnel into N regions, and the corresponding cavity volume of each region is

[0122] Step 3.5, select the installation position of support 1 in each region, remove the collapsed body 3 after the first stage of slag removal of the support installation position, and then install the support. After the support is installed, the steel bars 14 are connected to each other, as shown in Figure 3 ;

[0123] Step 3.6, install the expanded bag 5 at the top of the support 1, and divide the water in the expanded bag 5 to make the expanded bag 5 closely fit the rock wall in the cavity;

[0124] Step 3.7, adjust the height of the support 1 to make the top of each support 1 fit the bottom of the expanded bag 5.

[0125] The support 1 used in step 3 is a hydraulic support, the bottom of the support 1 is provided with a square base 15, the square base 15 is provided with a ground nail hole 17 around, a four rotating part 16 is sleeved near the top of the support 1, the rotating part 16 is rotatably connected with the support 1, and a steel bar hole 18 is formed in the side surface of the rotating part 16.

[0126] ​​Step 4, two-stage hole making and chemical grouting are carried out in the reinforced section to form the grouted rock mass 13 under the broken body 2 of the tunnel collapse, the grouted rock mass 13 including the grout stopping layer 8 and the consolidation layer 9;

[0127] The specific process of step 4 is as follows:

[0128] Step 4.1, the first stage hole making is carried out in the reinforced section using a hand drill, the drill rod is a hollow self-feeding anchor rod, the hole is formed at one time, the rod is connected using a connecting sleeve, the anchor rod is left in the rock mass, and the first stage grouting hole 6 is formed after the drill hole is communicated with the broken body on the top of the expansion bag, and a 10cm-30cm joint is reserved;

[0129] Step 4.2, the first stage grouting hole 6 is flushed clean with pressure water, the self-feeding anchor rod is segmented and plugged into the seamless steel pipe, the joints are welded and connected, and high-pressure air is used for blowing to ensure that there is no rock slag in the steel pipe, then the joint is welded at the tail end of the seamless steel pipe and connected with the grouting pump pipeline;

[0130] Step 4.3, when grouting, the first preparation of grout is not more than 15kg, the grout preparation barrel is placed in the cooling water tank for grout preparation, the proportion of each component is modified epoxy resin grout: curing agent: curing accelerator = 1000:70:10, artificial stirring is used to mix each component uniformly, then the grout is injected into the seamless steel pipe through the grouting pump to form the arch-shaped grout stopping layer 8 in the broken body 2 of the tunnel collapse;

[0131] Step 4.4, the reserved anchor rod joint is cut off, the grouting hole is closed, and the empty section in the hole is manually sealed with cement mortar mixed with an expanding agent, the expanding agent is mixed in an amount of 3%-3.5% of the cement;

[0132] Step 4.5, the second stage hole making is carried out in the reinforced section using a hand drill, and the second stage grouting hole 7 is formed after the drill hole is communicated with the broken body 2 on the top of the grout stopping layer, and a 10cm-30cm joint is reserved;

[0133] Step 4.6, the grout is injected through the second stage grouting hole 7 to form the arch-shaped consolidation layer 9 on the top of the grout stopping layer 8, the reserved anchor rod joint is cut off, the grouting hole is closed, and the empty section in the hole is manually sealed with cement mortar mixed with an expanding agent.

[0134] Step 5, the internal material of the expansion bag 5 is released, the second stage slag removal in the tunnel is carried out, and then the expansion bag 5 and the support 1 are removed;

[0135] Step 6, a steel arch 4 is built under the grouted rock mass 13, a pipe shed 11 is arranged between the steel arch under the grouted rock mass and the steel arch in the reinforced section, and a steel mesh 12 is laid, then the rapid-setting concrete is sprayed to separate the inside of the tunnel from the cavity to form a protective shell, and secondary lining reinforcement is carried out, finally, the hole is made in the cavity inside the reinforced section and backfilled.

[0136] Example 5

[0137] A method for quickly treating tunnel collapse using an assembled adaptive expansion bladder stent comprises the following steps:

[0138] Step 1: Reinforce the uncollapsed area around the tunnel collapse, including applying locking anchors on both sides of the steel arch frame in the uncollapsed area around the tunnel collapse, and welding the gaskets of the locking anchors to the arch frame. Then, determine whether water gushing occurs at the tunnel collapse site. If water gushing occurs, drain the tunnel and then proceed to step 2. If water gushing does not occur, proceed directly to step 2.

[0139] Step 2: measuring the height and volume of each area of ​​the tunnel collapse cavity 10, scanning the tunnel collapse cavity using a three-dimensional laser scanner, and constructing a three-dimensional model of the tunnel collapse cavity, thereby obtaining the height and volume of each area of ​​the cavity;

[0140] Step 3: Determine the required number of pillars 1 and their installation locations based on the height and volume of each area of ​​the tunnel collapse cavity 10, perform the first stage of slag removal on the tunnel collapse cavity 10, and then install the pillars 1 and expansion bladders 5. Fill the expansion bladders 5 with water in different areas to ensure that the expansion bladders 5 fit tightly against the rock wall in the cavity.

[0141] The specific process of step 3 is as follows:

[0142] Step 3.1, calculate the impact force of the debris from the top of the tunnel collapse cavity 10 falling to the top of the pillar 1 F 1:

[0143]

[0144]

[0145]

[0146] Where, M is the weight of the gravel at the top of the tunnel collapse cavity, M= pV , p is the rock density at the top of the tunnel, V is the volume of the tunnel collapse cavity, is the maximum falling velocity of the gravel at the top of the tunnel collapse cavity, The time it takes for the debris at the top of the tunnel collapse cavity to fall to the top of the support. is the time when the gravel contacts the pillar, H is the average height difference between the top of the tunnel collapse cavity and the top of the pillar, and the pillar height is the height of the top of the excavated cavern;

[0147] Step 3.2: Divide the tunnel collapse cavity 10 into n regions along the length of the tunnel. The volume of the cavity corresponding to each region is , , the number of pillars 1 required in each region is , the calculation formula is as follows:

[0148]

[0149] Where, F 1 is the impact force of the debris from the top of the collapsed tunnel cavity falling to the top of the pillar, F 2 is the bearing capacity of a single pillar, W1 is the maximum weight of the expansion bag after water injection;

[0150] If calculated If it is a decimal, use the rounding up method;

[0151] Step 3.3: Determine the number of pillars required for each area after rounding Is it greater than 1? The area with a value greater than 1 is divided again into N areas along the width of the tunnel. The corresponding cavity volume of each area is X j , X j ={ X 1, X 2,……, X N}, the number of pillars required in each region is , the calculation formula is as follows:

[0152]

[0153] If calculated If it is a decimal, use the rounding up method;

[0154] Step 3.4: Determine the number of pillars required for each area after rounding Is it greater than 1? The areas with a value greater than 1 are divided again until the number of pillars allocated to each area is 1;

[0155] Step 3.5, selecting the installation location of the pillar 1 in each area, performing the first stage of slag removal on the pillar installation location, removing the collapsed body 3, and then installing the pillars. After the pillars are installed, they are connected to each other using steel bars 14;

[0156] Step 3.6: Install an expansion bladder 5 on the top of the pillar 1. The expansion bladder 5 is a multi-cavity expansion bladder, each cavity of which is independent of the others and has its own water inlet and sealing plug. Fill the expansion bladder 5 with water in different sections so that the expansion bladder 5 fits tightly against the rock wall in the cavity.

[0157] Step 3.7, adjust the height of the pillars 1 so that the top of each pillar 1 fits the bottom of the expansion bag 5.

[0158] The support 1 used in step 3 is a hydraulic support, the bottom of the support 1 is provided with a square base 15, the square base 15 is provided with a ground nail hole 17 around, and four rotating parts 16 are sleeved near the top of the support 1, the rotating parts 16 are rotationally connected with the support 1, and a steel bar hole 18 is formed in the side surface of the rotating part 16.

[0159] Step 4, two-stage hole forming and chemical grouting are carried out in the reinforced section to form a grouting post-rock mass 13 under the broken body 2 of the collapse, the grouting post-rock mass 13 includes a grout stopping layer 8 and a consolidation layer 9;

[0160] The specific process of step 4 is as follows:

[0161] Step 4.1, a first-stage hole is formed in the reinforced section by using a hand air drill, the drill rod is a hollow self-feeding anchor rod, the hole is formed at one time, the anchor rod is connected by using a connecting sleeve, and the anchor rod is left in the rock mass. After the drill hole is communicated with the broken body on the top of the expansion bag, a first-stage grouting hole 6 is formed, and a joint of 10cm-30cm is reserved;

[0162] Step 4.2, the first-stage grouting hole 6 is flushed clean by using pressure water, a seamless steel pipe is segmented and inserted into the self-feeding anchor rod, the joints are welded and connected, and high-pressure air is used for blowing to ensure that there is no rock slag in the steel pipe. After that, a joint is welded at the tail end of the seamless steel pipe and connected with the grouting pump pipeline;

[0163] Step 4.3, when grouting, the first preparation of the slurry is not more than 15kg, the slurry preparation barrel is placed in a cooling water tank for slurry preparation, the proportion of each component is modified epoxy resin grout: curing agent: curing accelerator = 1000:70:10, manual stirring is used to mix each component uniformly, then the slurry is injected into the seamless steel pipe through the grouting pump, the grouting pressure is 6-8MPa, and the grout stopping layer 8 in the arch-shaped structure is formed in the broken body 2 of the tunnel collapse;

[0164] Step 4.4, the reserved anchor rod joint is cut off, the grouting hole is closed, and the empty section in the hole is manually sealed by using cement mortar mixed with an expanding agent, the expanding agent is mixed in an amount of 3%-3.5% of the cement;

[0165] Step 4.5, a second-stage hole is formed in the reinforced section by using a hand air drill, and a second-stage grouting hole 7 is formed after the drill hole is communicated with the broken body 2 on the top of the grout stopping layer, and a joint of 10cm-30cm is reserved;

[0166] Step 4.6, the slurry is injected through the second-stage grouting hole 7, the grouting pressure is 12-13MPa, the consolidation layer 9 in the arch-shaped structure is formed above the grout stopping layer 8, the reserved anchor rod joint is cut off, the grouting hole is closed, and the empty section in the hole is manually sealed by using cement mortar mixed with an expanding agent.

[0167] Step 5, release the internal substance of the inflatable bag 5, carry out the second stage of cleaning slag in the tunnel, then remove the inflatable bag 5 and the support 1;

[0168] Step 6, after grouting, build a steel arch 4 under the rock mass 13, arrange a pipe shed 11 between the steel arch under the grouted rock mass 13 and the steel arch of the reinforced section, and lay a steel mesh 12, then spray quick-setting concrete to separate the inside of the tunnel from the cavity to form a protective shell, and carry out secondary lining reinforcement, and finally drill holes into the cavity inside the reinforced section and backfill.

[0169] Step 6 specific process as follows:

[0170] Step 6.1, build a steel arch 4 under the grouting stop layer 8, determine the spacing between the steel arches 4 according to the surrounding rock grade of the construction area, for surrounding rock of grade III and above, the spacing between the steel arches 4 is 120 cm, for surrounding rock between type II and type III, the spacing between the steel arches 4 is 100 cm, and for surrounding rock below type II, the spacing between the steel arches 4 is between 50 cm and 80 cm;

[0171] Step 6.2, arrange a pipe shed between the steel arch under the grouting stop layer 8 and the steel arch of the reinforced section, and lay a steel mesh, then spray quick-setting concrete to separate the inside of the tunnel from the cavity to form a protective shell, and carry out secondary lining reinforcement;

[0172] Step 6.3, drill holes into the cavity inside the grouting stop layer bottom of the reinforced section, and set backfill grouting pipes, so that the holes are inclined upward, according to different drilling angles, the height of the grouting pipe outlet on one side of the cavity is different, and an exhaust hole and exhaust pipe are arranged near the top of the cavity;

[0173] Step 6.4, partially grout the cavity through grouting pipes of different heights, the grouting pressure value is 0.3 MPa, the grouting height is not more than 1 m each time, until the grouting hole stops absorbing grout, and the grouting is completed after 5 minutes of continuous grouting;

[0174] Step 6.5, remove the dirt in the grouting hole and the exhaust hole, use cement mortar to seal and compact the whole hole, and smooth it, and cut off the embedded pipe exposed on the surface of the lining concrete.

[0175] Example 6

[0176] A tunnel collapse rapid processing method using a fabricated self-adaptive inflatable bag support, comprising the following steps:

[0177] Step 1, reinforce the non-collapsed section around the tunnel collapse, including adding locking anchor rods on both sides of the steel arch in the non-collapsed section around the tunnel collapse, the anchor rod is Φ18 threaded steel bar with a length L of 1.5 m, and the washer of the locking anchor rod is welded and fixed with the arch, then it is judged whether water gushing occurs at the tunnel collapse, if water gushing occurs, drainage in the tunnel is carried out, then step 2 is carried out, if water gushing does not occur, step 2 is directly carried out;

[0178] Step 2, measure the height and volume of each region of the tunnel collapse cavity 10, use a three-dimensional laser scanner to scan the tunnel collapse cavity, construct a three-dimensional model of the tunnel collapse cavity, that is, obtain the height and volume of each region of the cavity, in this embodiment, the volume of the tunnel collapse cavity is 28.68m 3 ;

[0179] Step 3, determine the number of required support columns 1 according to the height and volume of each region of the tunnel collapse cavity 10, carry out the first stage of slag removal on the tunnel collapse cavity 10, then install the support column 1 and the expansion bag 5, and divide the expansion bag 5 for water filling to make the expansion bag 5 closely fit the rock wall in the cavity;

[0180] Referring to Figure 3 , Figure 3 , the tunnel collapse cavity 10 is a tunnel collapse cavity cross section schematic diagram at the height of the top of the support column 1, and the specific process of step 3 is as follows:

[0181] Step 3.1, calculate the impact force of the falling debris at the top of the tunnel collapse cavity 10 to the top of the support column 1 F 1:

[0182]

[0183]

[0184]

[0185] In the formula, M is the weight of the debris at the top of the tunnel collapse cavity, M= pV , p is the density of the rock mass at the top of the tunnel, V is the volume of the tunnel collapse cavity, in this embodiment, the rock mass at the top of the tunnel is gabbro, and the density is taken as 3.1 g / cm3, so the weight M of the debris that may fall at the top of the tunnel collapse cavity is 8.8908×104kg, H is the average height difference from the top of the tunnel collapse cavity to the top of the support column, the height of the support column is the height of the excavated chamber top, in this embodiment, the height of the excavated chamber top is 2.2 m, H is 2.669 m, is the time for the debris at the top of the tunnel collapse cavity to fall to the top of the support column, which is calculated as 0.738 s, is the maximum falling speed of the debris at the top of the tunnel collapse cavity, which is calculated as 7.2327 m / s, is the time for the gravel to contact the pillar, which is 0.2s, and the impact force F1 is calculated to be 3215.2kN;

[0186] Step 3.2: Divide the tunnel collapse cavity 10 into three equal areas along the tunnel length direction. The corresponding cavity volume of each area is , , V 1=7.32m 3 , V 2=11.25 m 3 , V 3=10.11 m 3 , the number of pillars 1 required in each region is , the calculation formula is as follows:

[0187]

[0188] Where, F 1 is the impact force of the debris from the top of the tunnel collapse cavity falling to the top of the pillar, F 2 is the bearing capacity of a single pillar. F 2 is 150kN, W1 is the maximum weight of the expansion bag after water injection, the required number of expansion bags is determined according to the volume of the collapsed cavity of the tunnel and the maximum volume of a single expansion bag, and then the maximum weight of the expansion bag after water injection is determined. The maximum volume of a single expansion bag used in this embodiment is 52m 3 The volume of the tunnel collapse cavity is 28.68m 3 , which is smaller than the maximum volume of a single expansion bladder, so one expansion bladder is sufficient. The weight of the expansion bladder after water filling is 30kg, so the maximum gravity after water filling is 0.294kN;

[0189] If calculated If it is a decimal, use the rounding up method;

[0190] After calculation, n 1=5.47, rounded up to 6 using the round-up method. n 2=8.41, rounded up to 9 using the round-up method. n 3=7.56, rounded up to 8 using the round-up method.

[0191] Step 3.3: Determine the number of pillars required for each area after rounding Is it greater than 1? The area with a value greater than 1 is divided again into N areas along the width of the tunnel. The corresponding cavity volume of each area is X j , X j ={ X 1, X 2,……,X N}, the number of pillars required in each region is , the calculation formula is as follows:

[0192]

[0193] If calculated If it is a decimal, use the rounding up method;

[0194] Step 3.4: Determine the number of pillars required for each area after rounding Is it greater than 1? The areas with a value greater than 1 are divided again until the number of pillars allocated to each area is 1;

[0195] Step 3.5, selecting the installation location of the pillar 1 in each area, performing the first stage of slag removal at the pillar installation location, removing the collapsed body 3, and then installing the pillars. After the pillars are installed, they are connected to each other using steel bars 14;

[0196] Step 3.6, install the expansion bladder 5 on the top of the pillar 1. The expansion bladder 5 is a multi-cavity expansion bladder. Each cavity is independent of each other and has its own water inlet and sealing plug. In this embodiment, the expansion bladder is a 5-cavity expansion bladder. The expansion bladder 5 is divided into sections and filled with water so that the expansion bladder 5 fits tightly to the rock wall in the cavity. Figure 4 ;

[0197] Step 3.7, adjust the height of the pillars 1 so that the top of each pillar 1 fits the bottom of the expansion bag 5.

[0198] The pillar 1 used in step 3 is a hydraulic pillar. A square base 15 is provided at the bottom of the pillar 1. Ground nail holes 17 are opened around the square base 15. Four rotating parts 16 are sleeved near the top of the pillar 1. The rotating parts 16 are rotatably connected to the pillar 1. Steel bar holes 18 are opened on the side of the rotating parts 16.

[0199] Step 4: Perform two-stage pore drilling and chemical grouting in the reinforced section to form a grouted rock mass 13 below the collapsed broken body 2. The grouted rock mass 13 includes a grouting layer 8 and a consolidation layer 9.

[0200] See also Figure 5 , the specific process of step 4 is as follows:

[0201] Step 4.1: Use a hand drill to drill the first stage of holes in the reinforced area. The drill rod is a φ25 hollow self-feeding anchor rod. The hole is drilled in one go. A connecting sleeve is used to connect the rods. The anchor rod is left in the rock mass. After the drill hole is connected to the broken body at the top of the expansion bag, the first stage grouting hole 6 is formed. A 10cm-30cm joint is reserved.

[0202] Step 4.2, the first stage grouting hole 6 is washed clean with pressure water, a φ13 seamless steel pipe is segmented and plugged into the self-feeding anchor rod, joints are welded and connected, and high-pressure air is used for blowing to ensure that there is no rock slag in the steel pipe, then a joint is welded at the tail end of the seamless steel pipe to connect with the grouting pump pipeline;

[0203] Step 4.3, when the grouting is started, the first preparation of the slurry is not more than 15 kg, the slurry preparation barrel is placed in the cooling water tank for slurry preparation, and the component preparation ratio is modified epoxy resin grouting liquid: curing agent: curing accelerator = 1000:70:10, the mixing order is that the modified epoxy resin grouting liquid is weighed first, then the curing accelerator is weighed and stirred for 1-3 minutes, then the curing agent is weighed and stirred for 1-3 minutes, then the slurry is injected into the seamless steel pipe through the grouting pump, the grouting pressure is 6-8 MPa, and the arch-shaped structure grouting layer 8 is formed in the tunnel collapse broken body 2 to prevent the second stage slurry from flowing back into the hole;

[0204] Step 4.4, the reserved anchor rod joint is cut off, the grouting hole is closed, and the empty section in the hole is manually closed with cement mortar mixed with an expanding agent, the component preparation ratio of the cement mortar is water: cement: sand = 0.3:1:1, and the expanding agent accounts for 3%-3.5% of the amount of cement, and the expanding agent is light burned MgO;

[0205] Step 4.5, the second stage hole is formed according to the first stage hole forming and grouting step, the second stage hole is formed in the reinforced section by using a hand air drill, the second stage grouting hole 7 is formed after the drilled hole is connected with the top broken body 2 of the grouting layer, and a 10 cm-30 cm joint is reserved;

[0206] Step 4.6, the slurry is injected through the second stage grouting hole 7, the slurry used is the same as that used in the grouting layer, the grouting pressure is 12-13 MPa, the arch-shaped structure consolidation layer 9 is formed above the grouting layer 8, the loose body is bonded, and the loose body sliding collapse is prevented to damage the tunnel support structure.

[0207] The reserved anchor rod joint is cut off, the grouting hole is closed, and the empty section in the hole is manually closed with cement mortar mixed with an expanding agent.

[0208] Step 5, the internal material of the expansion capsule 5 is released, the second stage clean-up of the tunnel is performed, and then the expansion capsule 5 and the support column 1 are removed;

[0209] Step 6, referring to Figure 6 After grouting, the steel arch 4 is built under the rock mass 13, the pipe shed 11 is arranged between the steel arch under the grouted rock mass 13 and the steel arch in the reinforced section, and the steel mesh 12 is laid, then the rapid-setting concrete is sprayed, the inside of the tunnel is separated from the cavity to form a protective shell, and secondary lining reinforcement is performed, and finally the hole is formed in the reinforced section and backfilled into the cavity.

[0210] Step 6 detailed process as follows:

[0211] Step 6.1, under the stop layer 8 steel arch 4, according to the construction area surrounding rock grade, determine the spacing between the steel arch 4 is 120cm;

[0212] Step 6.2, under the stop layer 8 steel arch and reinforcement section between the steel arch arrangement pipe shed and paving steel mesh, then spray quick-setting concrete, make the inside of the tunnel and cavity partition shell and secondary lining reinforcement;

[0213] Step 6.3, in step 1 reinforcement section to the bottom of the stop layer cavity hole and set backfill grouting pipe, make the hole inclined upward, according to the different angle of hole, realize the grouting pipe in the height of the cavity side outlet is different, close to the top of the cavity set exhaust hole and exhaust pipe, the number of hole according to the size of the cavity space to determine;

[0214] Step 6.4, through the different height of grouting pipe to the cavity part layer grouting, grouting pressure value is 0.3MPa, each grouting height does not exceed 1m, ensure not to the tunnel inside shell produces too large pressure, until the grouting hole stop suction grout, and continue to grouting 5min can end grouting, complete all grouting hole grouting;

[0215] Step 6.5, remove the grouting hole and exhaust hole in the dirt, use cement mortar to seal the whole hole dense and smooth, and cut off the embedded pipe exposed to the lining concrete surface.

Claims

1. A method for rapidly treating tunnel collapse using an assembled adaptive expansion bag stent, characterized in that: The following steps are involved: Step 1: Reinforce the uncollapsed area around the tunnel collapse, and determine whether water gushing occurs at the tunnel collapse site. If water gushing occurs, drain the tunnel and then proceed to step 2. If water gushing does not occur, proceed directly to step 2. Step 2, measuring the height and volume of each area of ​​the tunnel collapse cavity (10), scanning the tunnel collapse cavity (10) using a three-dimensional laser scanner, and constructing a three-dimensional model of the tunnel collapse cavity (10), that is, obtaining the height and volume of each area of ​​the cavity; Step 3, determining the required number of pillars (1) and installation positions according to the height and volume of each area of ​​the tunnel collapse cavity (10), performing the first stage of slag removal on the tunnel collapse cavity (10), and then installing the pillars (1) and the expansion bag (5). The expansion bag (5) is a multi-cavity expansion bag, each cavity is independent of each other, and has its own water inlet and sealing plug. The expansion bag (5) is filled with water in different areas so that the expansion bag (5) fits tightly against the rock wall in the cavity; The specific process of step 3 is as follows: Step 3.1, calculate the impact force of the debris from the top of the tunnel collapse cavity (10) falling to the top of the pillar (1) F 1: Where, M is the weight of the gravel at the top of the tunnel collapse cavity, M= ρV , ρ is the rock density at the top of the tunnel, V is the volume of the tunnel collapse cavity, is the maximum falling velocity of the gravel at the top of the tunnel collapse cavity, The time it takes for the debris at the top of the tunnel collapse cavity to fall to the top of the support. is the time when the gravel contacts the pillar, H is the average height difference between the top of the tunnel collapse cavity and the top of the pillar, and the pillar height is the height of the top of the excavated cavern; Step 3.2: Divide the tunnel collapse cavity (10) into n regions along the length of the tunnel. The corresponding cavity volume of each region is , , the number of pillars (1) required in each region is , the calculation formula is as follows: Where, F 1 is the impact force of the debris from the top of the tunnel collapse cavity falling to the top of the pillar, F 2 is the bearing capacity of a single pillar, W1 is the maximum weight of the expansion bag after water injection; If calculated If it is a decimal, use the rounding up method; Step 3.3: Determine the number of pillars required for each area after rounding Is it greater than 1? The area with a value greater than 1 is divided again into N areas along the width of the tunnel. The corresponding cavity volume of each area is X j , X j ={ X 1, X 2,……, X N }, the number of pillars required in each region is , the calculation formula is as follows: If calculated If it is a decimal, use the rounding up method; Step 3.4: Determine the number of pillars required for each area after rounding Is it greater than 1? The areas with a value greater than 1 are divided again until the number of pillars allocated to each area is 1; Step 3.5, selecting the installation location of the pillars (1) in each area, performing the first stage of slag removal on the pillar installation location, removing the collapsed body (3), and then installing the pillars. After the pillars are installed, they are connected to each other using steel bars (14); Step 3.6, installing an expansion bag (5) on the top of the pillar (1), and filling the expansion bag (5) with water in sections so that the expansion bag (5) fits tightly against the rock wall in the cavity; Step 3.7, adjusting the height of the pillars (1) so that the top of each pillar (1) fits the bottom of the expansion bag (5); Step 4, performing two-stage pore making and chemical grouting in the reinforced section to form a grouting rock mass (13) below the collapsed broken body (2), wherein the grouting rock mass (13) includes a grouting stop layer (8) and a consolidation layer (9); Step 5, releasing the contents of the expansion bag (5), carrying out the second stage of slag removal in the tunnel, and then removing the expansion bag (5) and the support (1); Step 6: A steel arch frame (4) is built below the grouting rock mass (13), a pipe shed (11) is arranged between the steel arch frame below the grouting rock mass (13) and the steel arch frame in the reinforced section, and a steel mesh (12) is laid. Then, quick-setting concrete is sprayed to separate the inner side of the tunnel from the cavity to form a protective shell, and secondary lining reinforcement is performed. Finally, a hole is made inside the cavity in the reinforced section and backfilled.

2. The method for quickly treating tunnel collapse using an assembled adaptive expansion bag stent according to claim 1, characterized in that: In the step 1, the non-collapsed section around the tunnel collapse is reinforced, including adding locking anchor rods on both sides of the steel arch frame in the non-collapsed section around the tunnel collapse, and welding the gaskets of the locking anchor rods to the arch frame.

3. The method for quickly treating tunnel collapse using an assembled adaptive expansion bag stent according to claim 1, characterized in that: The support (1) is a hydraulic support. A square base (15) is provided at the bottom of the support (1). Ground nail holes (17) are provided around the square base (15). Four rotating parts (16) are sleeved near the top of the support (1). The rotating parts (16) are rotatably connected to the support (1). Steel bar holes (18) are provided on the sides of the rotating parts (16).

4. The method for quickly treating tunnel collapse using an assembled adaptive expansion bag stent according to claim 1, characterized in that: The specific process of step 4 is as follows: Step 4.1, use a hand drill to drill the first stage of holes in the reinforced area. The drill rod is a hollow self-propelled anchor rod. The hole is drilled in one go. A connecting sleeve is used to connect the rods. The anchor rod is left in the rock mass. After the drill hole is connected to the broken body at the top of the expansion bag, the first stage grouting hole (6) is formed. A 10cm-30cm joint is reserved. Step 4.2, use pressurized water to flush out impurities in the first stage grouting hole (6), use seamless steel pipes to insert self-propelled anchor rods in sections, weld the joints, and use high-pressure air to blow them out. After ensuring that there is no rock debris in the steel pipe, weld the joint at the tail end of the seamless steel pipe and connect it to the grouting pump pipeline; Step 4.3, when grouting begins, the first slurry preparation shall not exceed 15 kg, and the slurry preparation bucket shall be placed in the cooling water tank for slurry preparation. The proportion of each component shall be modified epoxy resin grouting liquid: curing agent: curing accelerator = 1000:70:10, and the components shall be mixed manually to mix the components evenly. Then, the slurry shall be poured into the seamless steel pipe by a grouting pump to form an arch-shaped grouting layer (8) in the tunnel collapse crushed body (2); Step 4.4: Cut off the reserved anchor joint, seal the grouting hole, and manually seal the remaining hole with cement mortar mixed with an expansion agent. The expansion agent dosage is 3% to 3.5% of the cement dosage. Step 4.5, use a hand drill to drill the second stage of holes in the reinforced area, and after the drilled hole is connected with the broken body (2) at the top of the stop grouting layer, a second stage grouting hole (7) is formed, leaving a 10cm-30cm joint; In step 4.6, grout is injected through the second-stage grouting hole (7) to form an arch-shaped consolidation layer (9) above the grouting layer (8), the reserved anchor joint is cut off, the grouting hole is closed, and the remaining section in the hole is manually sealed with cement mortar mixed with an expansion agent.

5. The method for quickly treating tunnel collapse using an assembled adaptive expansion bag stent according to claim 4, characterized in that: A grouting layer (8) with an arched structure is formed in the tunnel collapse fragments (2), with a grouting pressure of 6-8 MPa, and a consolidation layer (9) with an arched structure is formed above the grouting layer (8), with a grouting pressure of 12-13 MPa.

6. The method for quickly treating tunnel collapse using an assembled adaptive expansion bag stent according to claim 1, characterized in that: In the step 6, a steel arch frame (4) is built below the grouting rock mass (13). The spacing between the steel arch frames (4) is determined according to the surrounding rock grade of the construction area. For surrounding rock of grade III or above, the spacing between the steel arch frames (4) is 120 cm. For surrounding rock between grade II and grade III, the spacing between the steel arch frames (4) is 100 cm. For surrounding rock below grade II, the spacing between the steel arch frames (4) is between 50 cm and 80 cm.

7. The method for quickly treating tunnel collapse using an assembled adaptive expansion bag stent according to claim 1, characterized in that: In step 6, a hole is made inside the cavity in the reinforced section and backfilled. The specific process is as follows: Step 6.1, in the reinforced section of step 1, a hole is made in the bottom cavity of the stop grouting layer (8) and a backfill grouting pipe is set, so that the hole is inclined upward, and the height of the grouting pipe outlet on one side of the cavity is different according to the different hole making angles, and an exhaust hole and an exhaust pipe are set near the top of the cavity; Step 6.2: Grout the cavity layer by layer through grouting pipes at different heights. The grouting pressure is 0.3 MPa and the grouting height does not exceed 1 m each time. Grouting is continued for 5 minutes to complete the grouting of all grouting holes. Step 6.3: Clean the dirt in the grouting holes and exhaust holes, seal and smooth the entire hole with cement mortar, and cut off the embedded pipes exposed on the lining concrete surface.

Images