Treatment method suitable for collapse of small-section diversion tunnel and auxiliary equipment thereof

Abstract

The invention provides a processing method and auxiliary equipment suitable for collapse of a small-section diversion tunnel, and the method comprises the following steps: S1, carrying out geologic body detection in front of a tunnel face, and obtaining the collapse probability; s2, construction is conducted according to design parameters of the diversion tunnel, wherein a weak blasting technology is adopted in the construction process in an area with the collapse probability larger than a preset value; s3, when collapse or collapse premonition is monitored, an alarm is given out in time; s4, tunnel face construction is paused; s5, the collapse part is treated according to the collapse condition; and S6, the collapse area is treated, and construction of the diversion tunnel is continued. When the collapse risk exists, timely reminding can be carried out, so that constructors can select to replace a construction mode or carry out treatment according to actual conditions, the collapse risk is further reduced, and the safety is higher; when the landslide occurs, a user can conveniently process the landslide area according to different landslide conditions, the method adapts to different landslide conditions, operation is easy, and the treatment cost is reduced through the proper treatment mode.

Description

Technical Field

[0001] This invention relates to the field of water diversion tunnel collapse treatment technology, specifically to a treatment method and auxiliary equipment applicable to small-section water diversion tunnel collapses. Background Technology

[0002] Water diversion tunnels are widely used in water diversion engineering structures, typically characterized by long routes, small diameters, narrow construction spaces, complex geological conditions, and deep burial depths. This invention is based on a Class III medium-sized project, primarily an underground water diversion tunnel. The surrounding rock is mainly Class III deep-buried hard rock, with some sections traversing shallow sections of gullies and rivers, and fractured fault zones, primarily Class IV and V geological conditions. The tunnel adopts a small-section portal-type structure and is constructed using traditional drill-and-blast methods. The tunnel's net cross-sectional dimensions are 3.0m × 3.5m (width × height), and the excavation cross-sectional dimensions for Class IV and V surrounding rock are 4.16m × 4.58m (width × height). The maximum excavated cross-section is 17.5m² (the excavation area is between 10 and 30m², which is considered a small cross-section).

[0003] The design support parameters for water diversion tunnels are determined based on the surrounding rock type. Generally, for Class II and III surrounding rock with relatively good conditions, a structure of wire mesh shotcrete and anchor support + plain concrete lining is adopted. For Class IV and V surrounding rock with poor conditions, a structure of advanced support + steel arch frame + wire mesh shotcrete and anchor support + reinforced concrete lining is adopted.

[0004] When water diversion tunnels traverse fault fracture zones, abrupt changes in surrounding rock, and areas of soft, seeping rock, collapses are common due to local joint structures. These collapses create irregularly sized cavities at the arch of the sidewalls, affecting the stability of the support structure. The longer the collapse lasts, the deeper the cavity, and the smaller the cavity. Sometimes, small collapses go unnoticed by engineers, and without timely reinforcement measures, they can escalate into large collapses, even causing cracking and significant deformation of the initial support structure, severely impacting tunnel construction progress and safety. Furthermore, due to the significant characteristics of regional geological structures and the heterogeneity of surrounding rock, there is a lack of mature experience and specific treatment methods for underground tunnels.

[0005] Existing collapse handling technologies are mostly designed for large-section tunnels and are difficult to adapt to the construction limitations of small-section tunnels. In actual construction, small collapses have not received enough attention, and areas with collapse risks are difficult to prevent in advance, thus posing safety hazards during construction. Furthermore, existing technologies are not convenient for selecting appropriate collapse handling methods for small-section tunnels based on different types of collapse causes, collapse types, and scales. Summary of the Invention

[0006] The main objective of this invention is to provide a method and auxiliary equipment for handling collapses in small-section water diversion tunnels, thereby solving the problems of existing technologies where collapse risks are significant and it is inconvenient to handle them on demand.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for handling the collapse of a small-section water diversion tunnel includes the following steps: S1. Conduct geological surveys in front of the tunnel face to obtain the probability of landslide; S2. Construct according to the design parameters of the water diversion tunnel; In areas where the probability of collapse is below the preset value, conventional construction methods are used while monitoring the rock mass; in areas where the probability of collapse is above the preset value, weak blasting technology is used during construction to increase the frequency of rock mass monitoring. S3. When a landslide or a precursor to a landslide is detected, an alarm should be issued in a timely manner; S4. Suspend construction at the working face; S5. Based on the extent of the landslide, address the affected area. S6. After the landslide area is treated, continue the construction of the water diversion tunnel until the construction is completed.

[0008] In the preferred scheme, the detection content in S1 includes: S11. A miniaturized seismic wave detector is used to probe the area in front of the tunnel face to preliminarily identify whether there are fractured areas of the fault and their approximate range. S12. Use ground-penetrating radar to conduct secondary detection on this section to monitor whether there are water-rich areas and the location of water-rich areas. S13. When a fractured area is detected, several advanced horizontal drills are constructed, and the development of rock fractures is observed through an in-hole imaging instrument to finally determine the core area of ​​the fault fracture zone. The probability of landslide is obtained based on the size of the fractured area, the size of the water-rich area, and the region.

[0009] In the preferred embodiment, in S5, the collapse is a minor collapse or a collapse in a Class III surrounding rock section: S511. Apply polypropylene fiber reinforced concrete to the working face and the surface of the collapsed cavity for temporary reinforcement and sealing. S512, the support structure of the collapsed section and the section affected by the collapse is strengthened by adopting a steel frame + anchor bolt flexible support structure, and shotcrete is used to seal it according to the design requirements; S513. Determine the backfilling treatment method based on the cavity height H: If H≤1m, the cavity is filled with steel mesh and sprayed with the same grade of concrete as the initial support. If H>1m, a grouting pipe is pre-embedded at the cavity opening, and a double layer of steel mesh is laid within the cavity. The spraying thickness is not less than 50cm. After the secondary lining of the tunnel is poured, the cavity is backfilled with grouting or pumped concrete to compact it. S514, Conduct water seepage detection at the collapse site; S515. When a leak is detected, drill holes at the location where the leak is concentrated and install drainage pipes to divert the internal water.

[0010] In the preferred embodiment, in S5, the collapse is a collapse of Class IV or Class V surrounding rock, and the collapsed body does not block the cavern, the boundary of the collapsed cavity is relatively flat, the depth of the collapsed cavity is relatively shallow, and there is no risk of continuous falling. S521. Apply polypropylene fiber reinforced concrete to the working face and the surface of the collapsed cavity for temporary reinforcement and sealing. S522, Double-layer advanced small guide pipes are set in the 100-130° range of the arch, with the upper layer having an outward insertion angle of 10-20° and the lower layer having an outward insertion angle of 5-10°, arranged alternately. Several layers of steel mesh are laid on the upper part, and then shotcrete is used to seal it to form a safety protection shed. The upper-level pre-construction pipe is inserted from the arch of the second steel arch closest to the collapse, and the lower-level pre-construction pipe is inserted from the arch of the first steel arch closest to the collapse. Threaded steel bars are inserted into the pre-construction pipes and they are filled and compacted with cement grout. S523. Clear the landslide debris and strengthen the support measures for the landslide section; S524. Radial grouting reinforcement of the collapsed section support: After the collapsed section is treated, radial grouting pipes are installed on the arch and sidewalls. S525. After radial grouting reinforcement, drainage holes are drilled.

[0011] In the preferred embodiment, in S5, the collapse is a Class IV or Class V surrounding rock section, and the collapsed body blocks the cavern, the boundary of the collapsed cavity is relatively rough, the depth of the collapsed cavity is relatively deep, and there is a risk of continuous falling. S531. Use the collapsed debris for counter-pressure backfilling to form a natural slope, and use shotcrete to seal the counter-pressure backfill surface. S532. Double-layer grouting pipes are installed in the arch area within 100-130° to grout and consolidate the collapsed body. The upper layer has an outer insertion angle of 10-20° and the lower layer has an outer insertion angle of 5-10°, and they are arranged alternately. The upper grouting pipe is inserted from the arch of the second steel arch closest to the collapse, and the lower grouting pipe is inserted from the arch of the first steel arch closest to the collapse. The grouting pipe passes through the collapsed cavity accumulation. S533. Clear the landslide debris and strengthen the support measures for the landslide section; S534. Radial grouting reinforcement of the collapsed section support: After the collapsed section is treated, radial grouting pipes are installed on the arch and sidewalls. S535. After radial grouting reinforcement, drainage holes are drilled. In the preferred embodiment, the grouting slurry is cement slurry or cement-water glass dual slurry, the water-cement ratio of the cement slurry is 1:0.5~1:1, and the grouting pressure is controlled at 0.5~1.0MPa. The specific grouting pressure can be adjusted according to the field test. Furthermore, when there is no or little seepage water in the above-mentioned collapsed section, cement grout is selected; when there is significant seepage water, cement-water glass dual grout is selected, with a cement grout to water glass volume ratio of 1:0.5 to 1:1.

[0012] An auxiliary device for handling the collapse of a small-section water diversion tunnel includes two supports, with a guide rod on the top of each support; The guide rod is an arc-shaped rod, and a fixing plate is provided at the end of the guide rod away from the support; The fixed plates are set horizontally, and several telescopic rods are provided between the two fixed plates to drive the various guide rods of the chain to move closer and further apart; The guide rod is equipped with several connecting frames and movable frames on its side. The connecting frames are equipped with a first detector, and the movable frames are equipped with a second detector. The first and second detectors are used to detect the condition inside the tunnel.

[0013] In a preferred embodiment, the support includes a support column, and a support seat is provided at the bottom end of the support column; Both the support base and the support column are equipped with rollers at their bottom ends; The top of the support column is provided with a placement groove, and the side of the placement groove is provided with a side plate; The placement slot is equipped with several lifting rods, and the top of each lifting rod is equipped with a flange, which is connected to the bottom of the guide rod.

[0014] In a preferred embodiment, the inner side of the guide rod is provided with a guide groove, and the connecting rod includes a movable arm rotatably connected within the guide groove; One end of the movable arm extends out of a guide groove and is equipped with a connecting plate, and the first detector is connected to the connecting plate; Several reinforcing rods are provided between the connecting plate and the movable arm; The movable arm is equipped with a rotating shaft at one end of the guide groove. The rotating shaft is set perpendicular to the movable arm and is rotatably connected to the inside of the guide rod. The inner side of the guide rod is equipped with a first motor, and the output shaft of the first motor is equipped with a worm gear; The worm is located inside the guide rod, and the shaft is equipped with a worm wheel, which meshes with the worm.

[0015] In the preferred embodiment, the movable frame includes a guide rail, which is arranged along the guide rod; The guide rod is positioned far from the connecting frame, so as not to affect the movement of the connecting frame; A movable seat is slidably connected to the guide rail. The guide rail has a T-shaped cross-section, and the movable seat has a T-shaped groove that matches the guide rail. The guide rail passes through the T-shaped groove. The surface of the guide rail is smooth to ensure stable sliding of the movable seat. The guide rail is equipped with a rack, which is set along the guide rail; The movable base is equipped with a second motor, and the output shaft of the second motor is equipped with a gear. The gear is located inside the movable base and meshes with a rack. The movable seat is equipped with a mounting plate, and the second detector is connected to the mounting plate.

[0016] This invention provides a method and auxiliary equipment for handling the collapse of small-section water diversion tunnels. By adopting the above solution, the following beneficial effects are achieved: During tunnel construction, the construction environment is monitored in real time to promptly alert workers when there is a risk of collapse. This allows construction personnel to choose to change construction methods or take appropriate measures based on the actual situation, thereby reducing the risk of collapse and increasing safety.

[0017] When encountering a landslide, it allows users to handle the landslide area according to different landslide conditions, adapting to different landslide situations. It is simple to operate, and the appropriate handling method reduces the handling cost.

[0018] The auxiliary equipment is suitable for small cross-sectional spaces, has a high monitoring coverage, and can move along with the construction progress to perform dynamic monitoring throughout the entire process, greatly reducing the workload of manual monitoring. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a structural schematic diagram from another perspective of the present invention; Figure 3 This is a side view of the present invention; Figure 4 This is a schematic diagram of the structure of the support of the present invention; Figure 5 This is an enlarged structural schematic diagram of the top end of the guide rod of the present invention; Figure 6 This is a cross-sectional view of the connecting frame of the present invention; Figure 7 This is a cross-sectional view of the movable frame of the present invention.

[0020] In the picture: Support 1, support column 101, support seat 102, roller 103, placement groove 104, side plate 105, lifting rod 106, flange 107, guide rod 2, connecting frame 3, movable arm 301, connecting plate 302, reinforcing rod 303, rotating shaft 304, worm gear 305, first motor 306, worm 307, first detector 401, second detector 402, telescopic rod 5, fixed plate 501, movable frame 6, guide rail 601, rack 602, movable seat 603, mounting plate 604, second motor 605, gear 606. Detailed Implementation

[0021] Example 1: A method for handling the collapse of a small-section water diversion tunnel includes the following steps: S1: Detect the geological body ahead of the working face to obtain the probability of landslide: Employing a three-tiered detection mode combining seismic wave detection, ground-penetrating radar, and advanced horizontal drilling, comprehensive geological information is acquired to accurately assess the probability of landslides. S11: Preliminary seismic wave detection: A miniaturized seismic wave detector is used to set up 3-5 detection points on the working face. The preferred model of the miniaturized seismic wave detector is YD-30, which is suitable for small cross-section operation. The preferred detection depth is 30-50m, and the preferred transmission frequency is 100-500Hz. By analyzing the changes in wave velocity and reflection signals, the approximate range of the fault fracture area is preliminarily identified, and the rock mass integrity coefficient Kv is determined. When Kv < 0.5, it is determined to be a high-risk fracture area.

[0022] S12: Secondary detection by ground-penetrating radar: A portable ground-penetrating radar, preferably model SIR-4000, is used to arrange detection lines along the transverse and longitudinal directions of the working face. By using the electromagnetic wave reflection characteristics, the presence and location of water-rich areas are monitored, and the water content ω of the water-rich areas is recorded. When ω > 20%, it is determined to be a high-risk water-rich area.

[0023] S13: Precise Horizontal Drilling Detection: When the fractured area is detected by S11-S12, 3-4 advanced horizontal drills are constructed. The preferred diameter is φ75-90mm, and the preferred depth is 20-50m. The drill holes are evenly distributed along the 120° range of the tunnel face arch, with a preferred spacing of 3-5m. The development of rock fractures, including fracture density and aperture, is observed using a borehole imaging instrument of model XY-200. Finally, the core area of ​​the fault fracture zone is determined.

[0024] Landslide probability assessment: Combining the size of the fractured area (S), the size of the water-rich area (V), and the degree of rock mass fissure development, the fuzzy comprehensive evaluation method is used to calculate the landslide probability (P): The preset collapse probability threshold is preferably... =60%, when P < 60%, it is judged as a low-risk area; when P ≥ 60%, it is judged as a high-risk area.

[0025] Evaluation index weights: fractured area size 0.4, water-rich area size 0.3, fracture development degree 0.3. Specific scoring criteria are preferred as follows: Size of the fractured region S: S<50㎡(60%); 50㎡≤S<100㎡(30%); S≥100㎡(0%); Water-rich area, large and small V: V<20㎡(80%); 20㎡≤V<50㎡(40%); V≥50㎡(0%); Crack development level: Crack density < 2 cracks / m (80%); 2-5 cracks / m (40%); > 5 cracks / m (0%).

[0026] S2: Graded construction, dynamically adjusting protection intensity: Construction will proceed according to the design parameters of the water diversion tunnel. Based on the collapse risk level determined by S1, a differentiated construction plan will be adopted: Low-risk areas (P < 60%): Conventional construction methods are adopted, namely drill-and-blast construction, with a cycle advance of 2-3m; rock mass monitoring frequency is once per cycle, and total station is used to monitor crown settlement and perimeter convergence.

[0027] High-risk areas (P≥60%): Weak blasting technology is adopted, with a cycle advance of 1.5-2m to reduce the disturbance of the rock mass by blasting; the rock mass monitoring frequency is 2 times per cycle, and the monitoring index of rock mass vibration velocity is increased, and vibration sensors are used for real-time monitoring; the preferred vibration sensor model is TC-4850.

[0028] S3: Landslide and Precursor Warning: Establish a dual early warning mechanism of "manual inspection + equipment monitoring": Warning indicators: Rock mass monitoring indicators exceeded the standards, such as crown settlement > 5 mm / d, peripheral convergence > 3 mm / d, and rock mass vibration velocity > 10 cm / s. Manual inspections revealed early signs of a landslide, such as falling blocks at the working face, opening of rock fissures, a sudden increase in water seepage, and unusual noises emanating from the surrounding rock. The auxiliary equipment's first detector 401 and second detector 402 detect signals of landslide or crack expansion. The first detector 401 and second detector 402 include, but are not limited to, an arch settlement monitor, a perimeter convergence monitor, a camera, a humidity sensor, and a vibration sensor.

[0029] Warning method: When any of the above warning indicators are met, the monitoring system will immediately issue an audible and visual alarm through the alarm device and push the warning information to the construction management personnel's mobile APP through the wireless transmission module; the monitoring system can use existing technology and commonly used controllers on construction sites, such as PLC controllers.

[0030] S4: Suspend construction at the working face: Upon receiving the warning signal, all operations at the working face should be immediately stopped, construction personnel and equipment should be evacuated to a safe area, warning signs should be set up, unauthorized personnel should be prohibited from entering, and special personnel should be assigned to continuously monitor the development of the landslide.

[0031] S5: Tiered landslide response: Based on the scale of the landslide, the grade of the surrounding rock, and the condition of the collapsed cavity, three types of treatment plans are adopted: Option 1: Minor landslides or landslides in Class III surrounding rock sections: S511: Temporary reinforcement and sealing: The working face and the surface of the collapsed cavity are initially sealed by sprayed polypropylene fiber concrete. The concrete strength grade is C25, the fiber content is 0.9kg / m³, the spraying thickness is 8-10cm, and the spraying pressure is 0.3-0.5MPa to ensure a tight seal and prevent the collapsed cavity from expanding further.

[0032] S512: Reinforced support structure: A flexible support structure of "steel frame + anchor bolts" is adopted. The steel frame is composed of circumferential Φ22mm threaded steel bars and longitudinal Φ12mm threaded steel bars that are perpendicularly intersected and tied or welded together. The longitudinal spacing of the circumferential bars is 20cm, and the circumferential spacing of the longitudinal bars is 40cm. The anchor bolts are φ22 hollow grouting anchor bolts, 2-4m in length, arranged in a staggered pattern, with an anchor bolt grouting pressure of 0.5-0.8MPa. After that, C25 concrete is sprayed to seal the structure, with a total spray thickness of 15-20cm.

[0033] S513: Backfilling of collapsed cavity: When the height of the collapsed cavity H≤1m, fill the cavity with φ6-8mm steel mesh, then spray concrete of the same grade as the initial support, backfill and compact it to ensure that the collapsed cavity and the support structure form an integral whole. When the collapse height H > 1m, a φ42 grouting pipe is pre-embedded at the collapse opening, and a double-layer steel mesh is laid within the collapse area, with an inner layer of φ6mm and an outer layer of φ8mm. The mesh size is 20cm×20cm. C25 concrete is sprayed with a thickness of not less than 50cm. After the tunnel secondary lining (C30 reinforced concrete, 30-40cm thick) is poured, backfill grouting (using C25 cement slurry, water-cement ratio 1:0.8) is carried out through the pre-embedded grouting pipe or C25 fine stone concrete is pumped to ensure that the collapse cavity is backfilled densely.

[0034] S514: Seepage detection: Use a seepage meter to detect water leakage at the collapse site, and record the location of the seepage point and the amount of seepage (Q); the preferred model of the seepage meter is HS-4.

[0035] S515: Seepage Treatment: When a seepage point is detected, a drainage hole is drilled at the location where the seepage is concentrated, and a φ40 drainage pipe is buried to concentrate the water and drain it to the tunnel side ditch to prevent seepage from softening the surrounding rock.

[0036] Option 2: The collapse occurred in a Class IV / V surrounding rock section. The collapsed material did not block the cavern, the boundaries of the collapsed cavity were relatively flat, the depth was shallow, and there was no risk of continued falling. S521: Temporary reinforcement and sealing: Same as Scheme 1 S511, spray polypropylene fiber concrete to seal the working face and the surface of the collapsed cavity.

[0037] S522: Set up a safety protection canopy: Install φ42×4mm double-layer advanced small guide pipes within a 100-130° range of the arch, with the upper layer having an outward insertion angle of 10-20° and the lower layer having an outward insertion angle of 5-10°, with a circumferential spacing of 40cm and a longitudinal row spacing of 80cm, and the upper and lower layers are arranged alternately; lay three layers of Φ8.0mm@20cm×20cm steel mesh on the top, and then seal it with 20cm thick C25 shotcrete to form a safety protection canopy; The upper-level pre-construction guide pipes are inserted from the arch of the second steel arch frame closest to the collapse, and the lower-level pipes are inserted from the arch of the first steel arch frame. φ22 threaded steel bars are inserted into the pre-construction guide pipes, and the pipes are filled and compacted with cement grout (water-cement ratio 1:0.5-1:1) (grouting pressure 0.5-0.8MPa). Two to three layers of steel mesh (φ8mm, 20cm×20cm mesh) are laid on top of the guide pipes, and C25 concrete (15-20cm thick) is sprayed to form a safety protective canopy to prevent rock from falling during the clearing of the collapse.

[0038] S523: Clearing the landslide and reinforcing the support: Use a small excavator in conjunction with manual labor to clear the landslide. The clearing sequence is from the outside to the inside, in layers and sections. Immediately after clearing each section, erect I16 I-beam arch frames at intervals of 0.6-0.8m. Weld the arch frames to the anchor rods and seal them with sprayed C25 concrete (15-25cm thick).

[0039] S524: Radial grouting reinforcement: After the collapse section support is completed, install radial grouting pipes (φ42×3.5mm, length 3-4m, spacing 1m×1m, external insertion angle 15-20°) on the arch and sidewalls. The grouting slurry should be selected as follows: For cases with little or no seepage (Q≤0.5L / min): use cement grout (water-cement ratio 1:0.5-1:1); For larger seepage flows (Q > 0.5 L / min): use a cement-water glass dual-slurry (cement slurry to water glass volume ratio 1:0.5-1:1); The grouting pressure is controlled between 0.5 and 1.0 MPa, and the specific pressure is adjusted according to the field test (based on the grout spreading to the design range without penetrating the surrounding rock).

[0040] S525: Drainage holes are drilled: 72 hours after radial grouting is completed, drainage holes are drilled in the arch and sidewalls to draw out the seepage water inside the surrounding rock, reduce the water content of the surrounding rock, and improve stability.

[0041] Option 3: A landslide occurred in a Class IV / V surrounding rock section, blocking the cavern. The boundary of the collapsed cavity is rough, and the depth is relatively deep, posing a risk of continued collapse. S531: Counter-pressure backfilling and surface sealing: The collapsed debris is used for counter-pressure backfilling to form a natural slope of 1:1.5-1:2. The counter-pressure backfilling height extends to 1-1.5m below the collapse cavity opening to prevent further collapse of the cavity. C25 shotcrete (10-12cm thick) is used to seal the surface of the counter-pressure backfilling to prevent weathering and loss of the debris.

[0042] S532: Grouting consolidation of the collapsed body: Install φ42×4mm double-layer grouting pipes within a 100-130° range of the arch, with the upper layer having an outer insertion angle of 10-20° and the lower layer having an outer insertion angle of 5-10°, a circumferential spacing of 40cm, and a longitudinal spacing of 80cm, with the upper and lower layers staggered; the upper layer grouting pipes enter from the arch position of the second steel arch frame closest to the collapsed area, and the lower layer enters from the arch position of the first steel arch frame. The grouting pipes need to pass through the collapsed cavity accumulation and penetrate into the stable surrounding rock ≥1m; the grouting slurry uses cement-water glass double slurry (parameters are the same as Scheme 2 S524), and the grouting pressure is 0.8-1.0MPa to ensure the consolidation of the collapsed body and eliminate the risk of continuous falling.

[0043] S533: Clearing the landslide and reinforcing the support: After the grouting solidification body reaches the required strength, use a small excavator in conjunction with manual labor to clear the landslide in layers and sections. Immediately after clearing a section, erect I18 I-beam arch frames with a spacing of 0.5-0.6m. The arch frames are fixed by welding φ22 longitudinal connecting bars. The arch frames are welded to the anchor rods and sealed with sprayed C25 concrete (25-30cm thick).

[0044] S534: Radial grouting reinforcement: Same as Scheme 2 S524, using radial grouting small pipes (φ42×3.5mm, length 4-5m) for grouting reinforcement, and adjusting the grouting parameters according to the on-site seepage volume.

[0045] S535: Drill drainage holes: Same as Scheme 2 S525, drill drainage holes to lead out seepage water and ensure that the surrounding rock is dry and stable.

[0046] S6: Resumption of construction: After the collapsed area was treated, the support structure was inspected for quality. An ultrasonic tester was used to test the concrete density, and an anchor pull-out tester was used to test the anchor pull-out force. After the test was passed, the working face construction was resumed. The original monitoring frequency was maintained throughout the construction process until the entire water diversion tunnel was completed.

[0047] Example 2: like Figure 1 , 2 As shown in Figures 3, 4, 5, 6, and 7, an auxiliary device for handling the collapse of a small-section water diversion tunnel is used for rock mass monitoring during the construction of the small-section water diversion tunnel. It mainly monitors the signs of collapse and the deformation of the support structure. It features miniaturization and flexibility, making it suitable for operation in narrow spaces with small cross-sections. The specific structure includes a support 1, a guide rod 2, a connecting frame 3, a detector, a telescopic rod 5, and a movable frame 6. The two supports 1 are symmetrically arranged and connected at the top by the guide rod 2. The detector includes a first detector 401 and a second detector 402. The first detector 401 is connected to the connecting frame 3, and the second detector 402 is connected to the movable frame 6 to achieve all-round monitoring.

[0048] Specifically, support 1 serves as the equipment support foundation, adaptable to small-section tunnel surfaces. It includes a support column 101, support base 102, rollers 103, a lifting rod 106, and a flange 107. Support base 102 is welded to the bottom of support column 101, preferably two support bases 102. Rollers 103 are installed at the bottom of both support base 102 and support column 101 to facilitate equipment movement within the tunnel. The rollers 103 may or may not be motor-driven depending on actual usage requirements; if a hub motor is used, the rollers 103 preferably feature a commonly used self-locking mechanism. A placement groove 104 is provided at the top of support column 101, and a side plate 105 is bolted to the side of the placement groove 104 to limit the lifting rod 106 and facilitate disassembly for maintenance or replacement. Two to four lifting rods 106 are installed in the placement slot 104. The lifting rods 106 are preferably hydraulic telescopic rods, preferably HT-300. The top of the lifting rod 106 is welded with a flange 107 and connected to the bottom of the guide rod 2 by bolts. When in use, the lifting rod 106 can be activated to drive the guide rod 2 to rise and fall, thereby adjusting the height of the guide rod 2 to adapt to the height of the tunnel and its actual use requirements.

[0049] Guide rod 2 is an arc-shaped rod with an arc adapted to the curvature of the tunnel arch, and a radius of 1.5-2.5m. It is preferably made of Q235 square steel welded together. A guide groove is opened on the inner side for installing the connecting frame 3. A fixing plate 501 is welded to the end of guide rod 2 away from support 1. Two to five telescopic rods 5 are installed between the two fixing plates 501. The telescopic rods 5 are preferably electric telescopic rods, preferably model DT-500. The telescopic rods 5 move the two guide rods 2 closer or further apart by extending and retracting, adapting to the tunnel width and actual usage requirements.

[0050] The connecting frame 3 is used to mount the first detector 401 and can achieve a 90° angle adjustment. It includes a movable arm 301, a connecting plate 302, a reinforcing rod 303, a rotating shaft 304, a worm gear 305, a first motor 306, and a worm 307. Specifically, a guide groove extends from one end of the movable arm 301, and the connecting plate 302 is welded thereto. The first detector 401 is connected and fixed to the connecting plate 302 by bolts. Two reinforcing rods 303 are welded between the connecting plate 302 and the movable arm 301 to enhance structural stability. A rotating shaft 304 is welded to one end of the movable arm 301 in the guide groove. The rotating shaft 304 is perpendicular to the movable arm 301 and is rotatably connected to the inside of the guide rod 2 through a bearing. A worm gear 305 is provided in the middle of the rotating shaft 304. A first motor 306 is installed on the inner side of the guide rod 2. The first motor 306 is preferably a DC geared motor of model ZGB37RG or a servo motor of the SGMPS series. The output shaft of the first motor 306 is connected to a worm gear 307 through a connector. The worm gear 307 meshes with the worm wheel 305. The first motor 306 drives the worm gear 307 to rotate by rotating forward and backward, thereby driving the worm wheel 305 to rotate. Finally, the rotating shaft 304 and the movable arm 301 can be rotated to adjust the monitoring angle of the first detector 401.

[0051] The movable frame 6 is used to install the second detector 402 and can slide along the guide rod 2 to achieve full-section monitoring. It includes a guide rail 601, rack 602, movable seat 603, mounting plate 604, second motor 605, and gear 606. Specifically, the guide rail 601 is a T-shaped guide rail, welded and fixed along the outside of the guide rod 2. The surface of the guide rail 601 is smooth to ensure stable sliding of the movable seat 603. A rack 602 is welded to one side of the guide rail 601. The movable seat 603 is made of cast aluminum alloy and has an internal T-slot adapted to the guide rail 601. The mounting plate 604 is welded to the outside of the movable seat 603, and the second detector 402 is connected and fixed to the mounting plate 604 by bolts. A second motor 605, preferably the same model as the first motor 306, is installed inside the movable seat 603. A gear 606 is welded to the output shaft of the second motor 605, and the gear 606 meshes with a rack 602. The gear 606 and rack 602 are compatible. The second motor 605 drives the gear 606 to rotate by reversing its direction, causing the gear 606 to move along the rack 602. Ultimately, this drives the movable seat 603 to slide along the guide rail 601, thereby adjusting the monitoring position of the second detector 402. Preferably, when adjusting the position of the movable seat 603, the movable arm 301 rotates to the inside of the guide rod 2 to avoid affecting the movement of the movable seat 603.

[0052] The connecting plate 302 and the mounting plate 604 are used to provide the installation positions for the first detector 401 and the second detector 402. The specific type of detector to be installed depends on the actual usage requirements. Preferred detectors include arch settlement monitoring instruments, perimeter convergence monitoring instruments, miniaturized seismic wave detectors, ground penetrating radar, cameras, humidity sensors, and vibration sensors, in order to detect the required data, which helps to reduce the probability of collapse and facilitates the selection of appropriate response plans after a collapse.

[0053] In use, the two supports 1 are moved to the tunnel monitoring section via rollers 103 and symmetrically arranged on both sides of the tunnel. The spacing between the two guide rods 2 is adjusted via telescopic rods 5 to match the tunnel width. The jacking rod 106 is activated to adjust the height of the guide rods 2 so that they fit against the underside of the tunnel arch. During construction, the auxiliary equipment of this application moves gradually via rollers 103 as the construction progresses at the tunnel face, achieving full-process dynamic monitoring. The detector collects data such as arch settlement and perimeter convergence in real time and transmits it to the construction monitoring platform via a built-in wireless transmission module. When the data exceeds the standard, the equipment's audible and visual alarms and mobile APP warnings are triggered simultaneously. Thus, the auxiliary equipment of this application can facilitate full-process dynamic monitoring during tunnel construction, provide timely warnings when encountering collapse risks and safety hazards, and obtain data in a timely manner to select appropriate treatment solutions when a collapse occurs, thereby facilitating the prediction and handling of tunnel collapses.

[0054] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for handling the collapse of a small-section water diversion tunnel, characterized by: Includes the following steps: S1. Conduct geological surveys in front of the tunnel face to obtain the probability of landslide; S2. Construct according to the design parameters of the water diversion tunnel; In areas where the probability of collapse is below the preset value, conventional construction methods are used while monitoring the rock mass; in areas where the probability of collapse is above the preset value, weak blasting technology is used during construction to increase the frequency of rock mass monitoring. S3. When a landslide or a precursor to a landslide is detected, an alarm should be issued in a timely manner; S4. Suspend construction at the working face; S5. Based on the extent of the landslide, address the affected area. S6. After the landslide area is treated, continue the construction of the water diversion tunnel until the construction is completed.

2. The method for handling the collapse of a small-section water diversion tunnel according to claim 1, characterized in that: In S1, the detection content includes: S11. A miniaturized seismic wave detector is used to probe the area in front of the tunnel face to preliminarily identify whether there are fractured areas of the fault and their approximate range. S12. Use ground-penetrating radar to conduct secondary detection on this section to monitor whether there are water-rich areas and the location of water-rich areas. S13. When a fractured area is detected, several advanced horizontal drills are constructed, and the development of rock fractures is observed through an in-hole imaging instrument to finally determine the core area of ​​the fault fracture zone. The probability of landslide is obtained based on the size of the fractured area, the size of the water-rich area, and the region.

3. The method for handling the collapse of a small-section water diversion tunnel according to claim 1, characterized in that: In S5, the collapse is either a minor collapse or a collapse in a Class III surrounding rock section: S511. Apply polypropylene fiber reinforced concrete to the working face and the surface of the collapsed cavity for temporary reinforcement and sealing. S512, the support structure of the collapsed section and the section affected by the collapse is strengthened by adopting a flexible support structure of steel frame and anchor bolts, and shotcrete is used to seal it according to the design requirements; S513. Determine the backfilling treatment method based on the cavity height H: If H≤1m, the cavity is filled with steel mesh and sprayed with concrete of the same grade as the initial support to compact it; if H>1m, a grouting pipe is pre-embedded at the cavity opening, and a double layer of steel mesh is laid within the cavity, with a spraying thickness of not less than 50cm. After the secondary lining of the tunnel is poured, the cavity is backfilled with grouting or pumped concrete to compact it. S514, Conduct water seepage detection at the collapse site; S515. When a leak is detected, drill holes at the location where the leak is concentrated and install drainage pipes to divert the internal water.

4. The method for handling the collapse of a small-section water diversion tunnel according to claim 1, characterized in that: in In S5, the collapse is a collapse of Class IV or Class V surrounding rock, and the collapsed body does not block the cavern, the boundary of the collapsed cavity is relatively flat, the depth of the collapsed cavity is relatively shallow, and there is no risk of continuous falling. S521. Apply polypropylene fiber reinforced concrete to the working face and the surface of the collapsed cavity for temporary reinforcement and sealing. S522, Double-layer advanced small guide pipes are set in the 100-130° range of the arch, with the upper layer having an outward insertion angle of 10-20° and the lower layer having an outward insertion angle of 5-10°, arranged alternately. Several layers of steel mesh are laid on the upper part, and then shotcrete is used to seal it to form a safety protection shed. The upper-level pre-construction pipe is inserted from the arch of the second steel arch closest to the collapse, and the lower-level pre-construction pipe is inserted from the arch of the first steel arch closest to the collapse. Threaded steel bars are inserted into the pre-construction pipes and they are filled and compacted with cement grout. S523. Clear the landslide debris and strengthen the support measures for the landslide section; S524. Radial grouting reinforcement of the collapsed section support: After the collapsed section is treated, radial grouting pipes are installed on the arch and sidewalls. S525. After radial grouting reinforcement, drainage holes are drilled.

5. The method for handling the collapse of a small-section water diversion tunnel according to claim 1, characterized in that: in In S5, the collapse is a Class IV or Class V surrounding rock section, and the collapsed body blocks the cavern. The boundaries of the collapsed cavity are relatively rough, the cavity is relatively deep, and there is a risk of continuous falling. S531. Use the collapsed debris for counter-pressure backfilling to form a natural slope, and use shotcrete to seal the counter-pressure backfill surface. S532. Double-layer grouting pipes are installed in the arch area within 100-130° to grout and consolidate the collapsed body. The upper layer has an outer insertion angle of 10-20° and the lower layer has an outer insertion angle of 5-10°, and they are arranged alternately. The upper grouting pipe is inserted from the arch of the second steel arch closest to the collapse, and the lower grouting pipe is inserted from the arch of the first steel arch closest to the collapse. The grouting pipe passes through the collapsed cavity accumulation. S533. Clear the landslide debris and strengthen the support measures for the landslide section; S534. Radial grouting reinforcement of the collapsed section support: After the collapsed section is treated, radial grouting pipes are installed on the arch and sidewalls. S535. After radial grouting reinforcement, drainage holes are drilled.

6. A method for handling the collapse of a small-section water diversion tunnel according to any one of claims 4 or 5, characterized in that: The grouting slurry uses cement slurry or cement-water glass dual slurry. The water-cement ratio of the cement slurry is 1:0.5~1:1, and the grouting pressure is controlled at 0.5~1.0MPa. The specific grouting pressure can be adjusted according to the field test. When there is no or little seepage water in the collapsed section, cement grout is selected; when there is significant seepage water, cement-water glass dual grout is selected, with a volume ratio of cement grout to water glass of 1:0.5 to 1:

1.

7. An auxiliary device for the treatment method of small-section water diversion tunnel collapse as described in any one of claims 1-6, characterized in that: It includes two supports (1), and a guide rod (2) is provided on the top of the support (1); The guide rod (2) is an arc-shaped rod, and a fixing plate (501) is provided at the end of the guide rod (2) away from the support (1); The fixing plate (501) is set horizontally, and several telescopic rods (5) are provided between the two fixing plates (501) to drive the chain guide rods (2) to move closer and further away from each other; The guide rod (2) is provided with several connecting frames (3) and movable frames (6) on its side. The connecting frame (3) is provided with a first detector (401), and the movable frame (6) is provided with a second detector (402). The first detector (401) and the second detector (402) are used to detect the internal conditions of the tunnel.

8. The auxiliary equipment for the treatment method of small-section water diversion tunnel collapse according to claim 7, characterized in that: The support (1) includes a support column (101), and a support seat (102) is provided at the bottom end of the support column (101). Both the support base (102) and the support column (101) are equipped with rollers (103) at their bottom ends. The top of the support column (101) is provided with a placement groove (104), and the side of the placement groove (104) is provided with a side plate (105). The placement slot (104) is provided with several lifting rods (106), and the top of the lifting rod (106) is provided with a flange (107), which is connected to the bottom of the guide rod (2).

9. The auxiliary equipment for the treatment method of small-section water diversion tunnel collapse according to claim 7, characterized in that: The inner side of the guide rod (2) is provided with a guide groove, and the connecting rod (3) includes a movable arm (301) that is rotatably connected in the guide groove. One end of the movable arm (301) extends out of the guide groove and is provided with a connecting plate (302), and the first detector (401) is connected to the connecting plate (302); Several reinforcing rods (303) are provided between the connecting plate (302) and the movable arm (301); The movable arm (301) is provided with a rotating shaft (304) at one end of the guide groove. The rotating shaft (304) is set perpendicular to the movable arm (301) and is rotatably connected to the inside of the guide rod (2). The inner side of the guide rod (2) is provided with a first motor (306), and the output shaft of the first motor (306) is provided with a worm gear (307). The worm (307) is located inside the guide rod (2), and the rotating shaft (304) is equipped with a worm wheel (305), which meshes with the worm (307).

10. The auxiliary equipment for the treatment method of small-section water diversion tunnel collapse according to claim 7, characterized in that: The movable frame (6) includes a guide rail (601), which is set along the guide rod (2); The guide rod (2) is positioned far from the connecting frame (3) so as not to affect the movement of the connecting frame (3); A movable seat (603) is slidably connected to the guide rail (601). The cross-section of the guide rail (601) is T-shaped. The movable seat (603) is provided with a T-shaped groove that matches the guide rail (601). The guide rail (601) passes through the T-shaped groove. The surface of the guide rail (601) is smooth for the stable sliding of the movable seat (603). The guide rail (601) is provided with a rack (602), and the rack (602) is arranged along the guide rail (601); The movable seat (603) is equipped with a second motor (605), and the output shaft of the second motor (605) is equipped with a gear (606). The gear (606) is located inside the movable seat (603) and meshes with the rack (602). The movable seat (603) is equipped with a mounting plate (604), and the second detector (402) is connected to the mounting plate (604).

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