Open-type TBM tunnel fault fracture zone in-tunnel parallel advanced detection and treatment integrated treatment method

Abstract

The invention relates to an open-type TBM tunnel fault fracture zone in-hole parallel advanced detection and treatment integrated treatment method which comprises the following steps: determining the position of a fault fracture zone in front of a tunnel according to a geological survey report, and calculating the TBM tunnel face mileage; ear holes are excavated in the side walls of the two sides of the tunnel in the TBM equipment bridge area; directional drilling machines are arranged in the lug holes in the two sides, and arc drilling is adopted to reach the fault fracture zone in front of the tunnel face of the tunnel; advanced detection is carried out in the directional drilling process; when it is judged that the risk that the broken zone surrounding rock in front of the TBM collapses and consequently the TBM gets stuck exists, consolidation grouting is conducted on the tunnel arch surrounding rock; when it is judged that the sudden gushing risk exists, curtain grouting is conducted on surrounding rock around the tunnel; and after grouting is completed, the grouting effect is tested. Advanced detection and pre-reinforcement treatment are integrated in the same construction process, a continuous operation system of sensing while drilling-intelligent identification-synchronous disposal is constructed, and seamless connection of geological risk advanced identification and engineering disposal is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering, and particularly relates to a method for integrally disposing parallel advanced exploration and treatment in a tunnel of an open TBM tunnel fault fracture zone. Background Technique

[0002] The open TBM is the key core equipment for tunnel construction in major water network projects in China at present. When the TBM crosses a regional fault fracture zone, its tunneling faces many challenges. The serious fragmentation and unevenness of the rock strata cause collapses above the shield and at the tunnel face, leading to problems such as TBM jamming, as well as sudden large-flow water and mud gushing problems under high external water pressure, often resulting in equipment jamming, system failure, or operation stagnation. These problems not only increase the construction difficulty but also directly affect the construction progress and cost.

[0003] Current technologies mostly rely on short-distance drilling and advanced grouting from behind the shield after the TBM stops to conduct local detection and pre-reinforcement. However, the limitations of this method are obvious: (1) The detection distance is insufficient and the grouting reinforcement time lags; (2) The space of the TBM equipment is narrow, and the number of boreholes drilled by the onboard advanced drill behind the shield is limited and the spacing is large, making it difficult to meet the treatment requirements of advanced consolidation grouting, and the drilling angle and depth are limited. If the method of excavating an enlarged working chamber is adopted, the difficulty is high, the time consumption is long, and the work efficiency is low; (3) There is a risk that the grout behind the shield will backflow to the contact surface between the cutter head shield and the surrounding rock, resulting in an increase in the TBM propulsion resistance or even complete jamming; (4) The advanced exploration and grouting behind the shield and the TBM tunneling need to alternate and stop operations, and the frequent switching of processes leads to a reduction in efficiency, restricting the continuous and efficient operation of the TBM.

[0004] Especially in areas with complex geological structures, the traditional advanced detection methods cannot timely and effectively feedback the changes in the fracture zone, and the resulting potential risks are more difficult to predict and control. With the development of tunnel construction technology towards deeper and more complex geological conditions, how to improve the tunneling efficiency while ensuring construction safety has become an urgent problem to be solved in various tunnel fields. Summary of the Invention

[0005] The present invention is proposed to solve the above deficiencies, and its purpose is to provide a method for integrally disposing parallel advanced exploration and treatment in a tunnel of an open TBM tunnel fault fracture zone. This method can not only effectively reduce the TBM downtime and improve the tunneling efficiency, but also minimize the impact of problems such as unstable jamming of broken rock mass and water and mud gushing on tunnel construction through accurate detection and timely reinforcement means, providing a more reliable safety guarantee for tunnel engineering.

[0006] To achieve the above purposes, the present invention adopts the following solutions:

[0007] An in - tunnel parallel advanced exploration and treatment integrated disposal method for the fault fracture zone of an open - type TBM tunnel, comprising the following steps:

[0008] S1: Determine the position of the fault fracture zone in front of the tunnel according to the geological exploration report, and calculate the mileage of the TBM face in combination with the daily progress of TBM tunneling, the theoretical drilling speed of the drill rig, and the construction period of the ear - hole excavation, so as to complete the ear - hole excavation, directional drilling exploration and treatment before the TBM reaches the fault fracture zone;

[0009] S2: When the distance between the TBM face and the fault fracture zone is within a predetermined distance, excavate ear - holes on both side walls of the tunnel in the TBM equipment bridge area. The position of the ear - holes is close to the TBM face and meets the directional drill steering space;

[0010] S3: Arrange directional drill rigs in the two ear - holes, adopt an arc - shaped drilling form and use a gyroscope for positioning to reach the fault fracture zone in front of the tunnel face;

[0011] S4: Conduct advanced detection during the directional drilling process, analyze the detection data, and comprehensively evaluate the geological risk situation of the fault fracture zone;

[0012] S5: When it is judged that there is a risk of TBM jamming due to the collapse of the surrounding rock in the front fracture zone of the TBM, consolidate grouting is carried out on the surrounding rock of the tunnel arch; when it is judged that there is a risk of gushing, curtain grouting is carried out on the surrounding rock of the tunnel perimeter;

[0013] S6: After the grouting is completed, test the grouting effect. After passing the test, continue the normal tunneling of the TBM and pass through the fault fracture zone.

[0014] As a preferred implementation method, in the step S1, the mileage of the TBM face satisfies the following relationship: The construction period for the directional drill rig to drill through and pass through the fault fracture zone is: ; The total time required for directional drill exploration - treatment is: ; The time required for the TBM to pass through the distance D2 required for the directional drill rig to change direction is: ; According to T TBM Greater than T 探查-治理 The requirement, that is ; The relationship between the mileage of the face and the starting mileage of the fault fracture zone: ; The mileage of the TBM face needs to satisfy: ; Wherein, X1: the mileage where the tunnel face is located; X2: the starting mileage of the fault fracture zone; D1: the distance between the TBM equipment bridge area and the TBM tunnel face; D2: the distance required for the directional drill to change direction; D3: the width of the fault fracture zone; V1: the tunneling speed of the TBM; V2: the theoretical drilling speed of the directional drill in this formation; T TBM : the time required for the TBM to tunnel from the current mileage to before the fault fracture zone; T 探查-治理 : the total construction period for completing the ear - hole construction, drill - rig drilling, and grouting treatment; T1: the construction period of the ear - hole construction; T2: the construction period for the drill - rig to reach the fault fracture zone; T3: the construction period for grouting treatment of the fault zone.

[0015] As a preferred implementation method, in step S3, the directional drilling construction is completed within the range of 2 - 5 m outside the tunnel excavation contour line.

[0016] As a preferred implementation method, in step S3, several exploration boreholes are constructed in the crown using the two - side ear - holes, and the target area for detection is within the range of 2 - 5 m outside the excavation contour line of the tunnel arch shoulder.

[0017] As a preferred implementation method, in step S4, before entering the fault zone, advanced detection work is carried out by combining the state of the drilled slag, the parameters of the drill - rig while drilling, and the natural gamma detector. After entering the fault, detection is carried out by combining core - drilling, the parameters of the drill - rig while drilling, and the natural gamma detector.

[0018] As a preferred implementation method, the parameters of the drill - rig while drilling include the torque, rotation speed, impact power of the drill - rig, and the parameters of the drilling stroke.

[0019] As a preferred implementation method, in step S5, when it is determined that there is a risk of collapse of the surrounding rock in the front - facing fracture zone of the TBM, causing the risk of TBM jamming, consolidation grouting is carried out on the surrounding rock of the tunnel arch using the exploration boreholes in the crown.

[0020] As a preferred implementation method, in step S5, when it is determined that there is a risk of sudden water inrush, while grouting operations are carried out in the exploration boreholes in the crown, directional drilling and high - pressure grouting work of several supplementary boreholes are simultaneously carried out at the invert, and curtain grouting is carried out on the surrounding rock of the tunnel circumference.

[0021] As a preferred embodiment, in the step S5, the grouting method is all segmental progressive grouting. The reserved rock pillar of the TBM face away from the boundary of the fault zone is used as the grout stop wall. The hole grouting is carried out by lowering the perforated pipe. The grouting materials are modified single-fluid cement slurry and cement-sodium silicate double-fluid slurry;

[0022] The grouting pressure is 1.5 to 2 times the measured external water pressure at the location of the grouting section. The effective diffusion radius of the slurry is 8 to 10 m. The grouting diffusion intersects to form an effective grouting reinforcement body within the diffusion radius with the center of the tunnel section as the center of the circle.

[0023] As a preferred embodiment, in the step S6, after the grouting is completed, a water pressure test is carried out to test the grouting effect. If the water permeability rate after grouting in the grouting area is <5 Lu, it is determined to be qualified.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] First, the in-tunnel parallel advanced exploration and treatment integrated disposal method for the fault fracture zone of the open TBM tunnel of the present invention, by selecting a reasonable timing for arranging the directional drilling holes, saves the drilling length of the directional drilling to the greatest extent without affecting the continuous tunneling of the TBM. At the same time, it innovatively combines directional drilling, gyroscopic guidance and natural gamma measurement technologies, provides more accurate geological information, and thus can better provide guarantee for the construction of the open TBM.

[0026] Second, the present invention integrates advanced detection and pre-reinforcement treatment into the same construction process, constructs a continuous operation system of "perception while drilling-intelligent identification-synchronous disposal", and realizes the seamless connection between geological risk advanced identification and engineering disposal. Compared with the traditional process, its core advantage is reflected in significantly improving the construction continuity of the TBM. Targeted reinforcement is completed before the face has not fully exposed the risk area, effectively avoiding problems such as shutdown, jamming and flooding caused by geological mutations; at the same time, relying on the information sharing of the exploration-treatment process, redundant construction links are eliminated, the process cycle is greatly compressed, and the construction progress is guaranteed while reducing the consumption of grouting materials.

[0027] Third, the present invention fundamentally changes the passive emergency operation mode in the disposal of the TBM passing through the fault fracture zone. By constructing an active defense system, the risks of surrounding rock instability, TBM jamming and mud and water inrush are systematically reduced, providing a reliable guarantee for the efficient tunneling of the TBM in complex strata.

[0028] Fourthly, in terms of the construction time limit control of the fault treatment of the present invention, by comprehensively considering the TBM tunneling progress, the drilling speed, and the required construction period for treatment, the time window for completing the lateral ear - hole excavation and directional drilling in advance is inversely calculated, and the relational formula for the minimum reserved advancing distance of the TBM working face is derived, ensuring that when the TBM approaches the fault zone, sufficient distance is reserved to complete the advanced reinforcement treatment without excessive shutdown, thus realizing the synchronous optimization of tunneling and treatment. Traditional methods often lack such quantitative algorithms and mostly determine the shutdown distance based on experience, which may cause risks of excessive waiting or insufficiency. The present invention realizes the overall planning of fault pre - reinforcement and continuous TBM tunneling, making the advanced treatment more time - efficient and controllable, and improving the construction organization efficiency and safety margin.

[0029] Fifthly, the present invention has a breakthrough innovation in the integrated layout of detection - treatment. "Ear - holes" are excavated on both sides of the TBM equipment bridge area as advanced construction platforms, and directional drilling rigs are arranged to implement arc - shaped trajectory drilling. Using a gyroscope for precise guidance, the boreholes bypass the TBM front and reach the target area of the front - facing fault fracture zone. For the first time, multi - dimensional space utilization is realized in the tunnel: the construction working face is expanded through the lateral ear - holes, and the arc - shaped directional drilling breaks through the limitation that only straight detection holes can be drilled at the general TBM working face. More importantly, this layout enables the parallel development of advanced detection and reinforcement operations, partially separated from the narrow space of the TBM front, forming a spatial stagger and coordination with the construction of the TBM main machine. For example, by completing the detection boreholes and pre - reinforcement grouting in the ear - holes, the detection and pretreatment work that traditionally requires the TBM to stop can be advanced and completed in parallel; compared with the existing technology that mainly relies on the detection holes built in the TBM body or short - distance pipe - shed construction, this multi - dimensional integrated layout greatly improves the coverage range and efficiency of the fault advanced treatment, and is the first of its kind for the synchronous construction of advanced detection and treatment in the tunnel.

[0030] Sixthly, in terms of geological risk detection and decision-making, the method of the present invention constructs an innovative application of a fusion-type multi-source perception system. During the drilling process, multi-parameter information is synchronously collected, including the morphology of rock debris, construction parameters while drilling (such as drilling pressure, torque, penetration rate, etc.), and natural gamma anomalies in the borehole. The data from different sensing channels are integrated and analyzed to form a comprehensive assessment of the geological risks in the fault zone. Through multi-source data fusion, adverse geological features in the front fault fracture zone, such as lithology mutation, water-rich anomaly, or thickness of loose zone, can be identified earlier and more accurately. Based on this, the established decision-making logic can automatically distinguish potential risk types: if there is a risk of jamming, it warns of unstable surrounding rock; if there is a risk of sudden gushing, it warns of a highly water-bearing and pressure-fractured zone. Traditional TBM advanced prediction methods mainly rely on single sensing technologies (such as the independent application of seismic wave method or resistivity method), making it difficult to comprehensively judge in a timely manner. The present invention organically integrates engineering, geological, and geophysical information, reflecting the innovation of advanced prediction through multi-sensor information fusion, improving the reliability of risk identification and the intelligent level of decision-making, and providing a scientific basis for timely selection of reinforcement measures on site.

[0031] Seventhly, in terms of the advanced reinforcement technology, the present invention has made innovative designs on the grouting method, grouting material, and diffusion control according to the construction characteristics of TBM to improve the adaptability to TBM tunneling. First, the segmented progressive grouting process is adopted: the advanced long borehole is divided into several sections, and grouting is carried out step by step forward in segments, and a high-pressure grout stop wall (such as the intermediate plugging section) is set up to control the slurry from flowing into non-target areas, ensuring the formation of a continuous and dense reinforcement curtain in the fault fracture zone; secondly, the advantages of quick hardening and high permeability are complemented by combining the use of grouting materials; thirdly, the grouting pressure is strictly controlled within the range of 1.5 to 2 times the external water pressure: this pressure control criterion not only ensures that the slurry has enough power to overcome the groundwater pressure and penetrate into the rock fissures, but also avoids further damage to the surrounding rock or excessive loss of slurry caused by too high pressure. The above innovations enable the water permeability of the reinforced surrounding rock to be reduced to <5 Lu after the water pressure test, forming an almost impermeable reinforcement zone. For TBM, this means that the surrounding rock has been significantly reinforced when passing through the fault zone, the groundwater has been effectively blocked, and the risk of the cutterhead getting stuck due to sudden water inrush and collapsed loose bodies has been greatly reduced. Compared with the combination of face chemical grouting and pipe shed advanced support commonly used for traditional open TBM to pass through faults, the high-pressure multi-section full-face curtain grouting of the present invention has obvious improvements in both the reinforcement effect and the adaptability to continuous TBM tunneling.

[0032] In summary, the innovation of the present invention lies in organically integrating detection and treatment into an integrated process, and synchronously completing it before the TBM tunneling process, minimizing the time for the TBM to stagnate due to detection and reinforcement. Through the innovative layout of ear holes + directional drilling, the expansion coverage of advanced reinforcement from "line" to "surface" is achieved; through the fusion judgment of multi-source information, the leap from experience-based decision-making to data-driven intelligent decision-making is realized; through the grouting process optimized for TBM, the improvement of the pre-reinforcement effect from "generally reliable" to "highly adaptable" is achieved. These breakthroughs effectively make up for the shortcomings of existing TBM fault crossing technologies at home and abroad. Against the background of the long-term trouble of TBM construction in complex fault zones, this parallel advanced exploration and treatment integrated disposal method provides a new solution idea, deeply coupling detection and prediction, advanced reinforcement and mechanical tunneling, significantly improving the safety and construction efficiency of TBM tunnels crossing fault fracture zones, and having significant technological innovation advantages and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic plan view of the ear holes and directional drilling on both sides of the TBM tunnel;

[0034] Figure 2 It is a schematic sectional view of the ear hole and borehole layout;

[0035] Figure 3 It is a schematic diagram of the layout of the crown grouting section and grouting intersection;

[0036] Figure 4 It is a schematic diagram of the layout of the circumferential grouting section and grouting intersection;

[0037] Figure 5 It is a schematic flow chart of the in-tunnel parallel advanced exploration and treatment integrated disposal method for the fault fracture zone of the open TBM tunnel in the embodiment of the present invention;

[0038] In the figure, 1 - ear hole construction area, 2 - directional drilling axis of the directional drilling rig, 3 - fault fracture zone, 4 - crawler-type directional drilling rig, 5 - equipment bridge area, 6 - tunnel, 7 - ear hole, 8 - tunnel excavation section, 9 - borehole diameter of the drilling circle, 10 - diameter of the slurry diffusion circle, D1 - distance from the equipment bridge area of the TBM to the TBM face, D2 - distance required for the directional drilling rig to change direction, D3 - width of the fault fracture zone, Z1 - first exploration borehole, Z2 - second exploration borehole, Z3 - first supplementary borehole, Z4 - second supplementary borehole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be understood that the accompanying drawings are only for illustrative purposes and cannot be construed as a limitation of this patent; for better illustration of this embodiment, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as a limitation of this patent.

[0041] An in-tunnel parallel advanced exploration and treatment integrated disposal method for the fault fracture zone of an open TBM tunnel in the present invention includes:

[0042] S1: Determine the position of the fault fracture zone in front of the tunnel according to the geological exploration report, and calculate the TBM face mileage in combination with the daily advance of TBM tunneling, the theoretical drilling speed of the drill rig, and the construction period of the ear hole excavation, so as to complete the ear hole excavation, directional drilling exploration and treatment before the TBM reaches the fault fracture zone; the fundamental requirement for determining the TBM face mileage is to complete the in-tunnel directional drilling exploration and treatment before the TBM reaches the fault fracture zone without affecting the normal tunneling of the TBM in the fault fracture zone; that is, the construction period of the ear hole excavation, the construction period for the drill rig to reach the fracture zone, and the construction period required for grouting in the fracture zone should be less than the construction period required for the TBM to tunnel through D2. The formula is as follows: The construction period for the directional drill rig to reach and pass through the fault fracture zone is: ; The total time required for directional drilling exploration - treatment is: ; The time required for the TBM to pass through the distance D2 where the directional drill rig changes direction is: ; According to T TBM Greater than T 探查-治理 Requirements, that is ; The relationship between the mileage of the face and the starting mileage of the fault fracture zone: ; The TBM face mileage needs to meet: ; In the formula, X1: The mileage of the face; X2: Starting mileage of the fault fracture zone; D1: Distance between the TBM equipment bridge area and the TBM heading face; D2: Distance required for the directional drill to change direction; D3: Width of the fault fracture zone; V1: TBM tunneling speed; V2: Theoretical drilling speed of the directional drill in this formation; T TBM : Time required for the TBM to tunnel from the current mileage to before the fault fracture zone; T 探查-治理 : Total construction period for completing the earhole construction, drill rig drilling, and grouting treatment; T1: Construction period of the earhole construction; T2: Construction period for the drill rig to reach the fault fracture zone; T3: Grouting treatment construction period of the fault zone.

[0043] S2: When the TBM heading face is at a predetermined distance from the fault fracture zone, earholes are excavated on both side walls of the tunnel in the TBM equipment bridge area. The earhole positions are close to the TBM heading face and meet the directional drill direction-changing space; the TBM equipment bridge area has the working space for earhole excavation, and it is close to the heading face to reduce the ineffective drilling length. The target area for advanced detection is the fault fracture zone in front of the heading face. The distance from the TBM shield tail to the already excavated and exposed rock of the rear earhole is the ineffective drilling length. After the earhole excavation layout in the TBM equipment bridge area is completed, the drilling work can be officially carried out.

[0044] S3: Directional drill rigs are arranged in the two side earholes, and the arc drilling form is adopted and positioned using a gyroscope to reach the fault fracture zone in front of the tunnel heading face; based on the previous geological exploration results and the spatial position of the earholes, an arc drilling trajectory is designed to ensure that the drilling holes accurately cover the fault fracture zone area in front of the tunnel axis. To improve the grouting effect, the method of opening earholes on both sides of the tunnel is adopted. Through this design of opening earholes on both sides, advanced detection and grouting treatment operations can be carried out simultaneously from both sides, enabling the advanced detection to cover a larger range on both sides of the tunnel and enhancing the efficiency and effect of the advanced grouting treatment, avoiding problems such as limited exploration range and insufficient local grouting consolidation caused by only carrying out directional drilling from one side. For the drilling part, according to the previous designed arc, a high-precision gyroscope guidance system is used to correct the drilling hole azimuth in real time, so that the directional drilling hole trajectory is always kept within the range of 2 - 5 m outside the tunnel excavation contour line. For the exploration part of the exploration-treatment integration, one exploration drilling hole is implemented in each of the two side earholes, and the detection target area is within the range of 2 - 5 m outside the tunnel arch shoulder excavation contour line.

[0045] S4: Conduct advanced detection during the directional drilling process, analyze the detection data, and comprehensively evaluate the geological risk situation of the fault fracture zone; before entering the fault zone, carry out advanced detection work by combining the state of drilled cuttings, the parameters of the drill rig while drilling, and the natural gamma detection technology. After entering the fault, use core drilling, the parameters of the drill rig while drilling, and the natural gamma detection technology for detection. During the drilling process, by collecting core or cuttings samples, the lithology and fragmentation degree of the formation can be directly judged, and the specific boundary of the fault fracture zone can be identified, providing a basis for grouting treatment. The analysis and acquisition system of the drill rig parameters while drilling collects parameters such as the torque, rotation speed, impact power, and drilling stroke of the drill rig, and inversely calculates the physical and mechanical properties of the rock mass (uniaxial compressive strength and rock mass fragmentation degree) through a regression model. Adopt a directional natural gamma testing technology, use two azimuth natural gamma sensors with an included angle of 180°, and finally convert it into an azimuth gamma count value in cps through a data processing device, which can directly judge the formation information in the borehole and conduct lithology division. Through the above technologies, the integrity, fracture development degree, and water content of the rock mass in front of the TBM can be analyzed in real time.

[0046] During this process, various exploration technologies can be flexibly added according to the requirements of different projects to ensure that the detection purposes under different geological conditions are met. For example, in the case of complex hydrogeological conditions or a strong aquifer in the fault fracture zone, acoustic imaging technology, electromagnetic wave detection technology, or ground penetrating radar technology can be combined to further enhance the detection ability of factors such as formation fractures, aquifers, and water inrush. For projects that require deep and refined detection of the fracture zone, microseismic monitoring and borehole imaging technology can be used to obtain the dynamic changes of the rock mass and the accurate three-dimensional formation distribution in real time, further optimizing the delineation of the fault fracture zone boundary.

[0047] This flexible combination of exploration schemes can not only effectively improve the accuracy of exploration, but also provide more suitable technical means for the requirements of different projects and different geological environments, ensuring a more accurate fault fracture zone detection scheme in complex geological environments.

[0048] For the treatment part in the integration of exploration and treatment, give priority to implementing 2 exploration boreholes (exploration boreholes also serving as grouting holes) in the crown arch. After the exploration boreholes reach the fault fracture zone, start the core drilling operation, and comprehensively study and judge the geological conditions of the fault fracture zone by combining the parameters of the drill rig while drilling and the natural gamma detection technology.

[0049] S5: When it is judged that the surrounding rock of the broken zone ahead of the TBM is at risk of collapse, resulting in the TBM getting stuck, consolidation grouting is carried out on the surrounding rock of the tunnel arch; when it is judged that there is a risk of sudden surge, curtain grouting is carried out on the surrounding rock around the tunnel; if the surrounding rock of the fault is extremely broken and poorly cemented, and the water output of the borehole is relatively small, it is judged that the surrounding rock of the broken zone ahead of the TBM is at risk of collapse, resulting in the TBM getting stuck, and there is no risk of sudden surge, two exploration boreholes in the top arch are used for pretreatment of the surrounding rock consolidation grouting of the tunnel arch; if the return water volume in the exploration borehole increases suddenly, the flow rate and water pressure are monitored in real time through the orifice. If the water output shows no decreasing trend and the gushing water is pressurized, it is judged that there is a large risk of sudden surge, and while grouting operations are being carried out in the two exploration boreholes in the top arch, directional drilling and high-pressure grouting work are carried out simultaneously in two supplementary boreholes in the invert arch, forming a continuous closed grouting curtain around the tunnel.

[0050] In this scheme, the reserved rock pillar at the distance from the TBM face to the fault zone boundary is used as a grouting wall. The grouting method adopts segmented forward grouting, and the hole grouting is carried out by lowering the flower pipe. The grouting materials used are modified single-liquid cement slurry and cement-water glass two-liquid slurry. The grouting pressure is determined according to the external water head (grouting pressure = 1.5-2 times the measured external water pressure at the location of the grouting section). Based on the effective grouting diffusion radius of 8-10m, the grouting diffusion circle forms an effective grouting reinforcement body with a certain radius range centered on the center of the tunnel section, thereby achieving a one-time grouting reinforcement treatment of the top arch or circumference of the tunnel section in the fault fracture zone in front.

[0051] S6: After the grouting is completed, a water pressure test is carried out to test the grouting effect. If it passes the test (the permeability of the grouting area after grouting is <5Lu), the TBM continues to advance normally and pass through the fault fracture zone.

[0052] Example:

[0053] The method for parallel advanced exploration and treatment of a fault fracture zone in an open TBM tunnel of the present invention comprises the following steps:

[0054] S1: An open-type TBM was used for the tunnel, with an excavation diameter of 10.0 m. The TBM bridge was 35 m from the cutterhead. Based on the location of the fault fracture zone identified in the preliminary geological survey report, the TBM's daily advances, the theoretical drilling rate, and the ear hole excavation schedule, the appropriate TBM face distance for ear hole construction was calculated.

[0055] S2: When the TBM face is at a predetermined distance from the fault fracture zone 3, ear holes 7 are excavated on both sides of the side walls of the tunnel 6 in the TBM equipment bridge area. The ear hole construction area 1 is arranged in the equipment bridge area 5. An ear hole with a depth of 4m, a length of 10m, and a height of 3m is excavated on both sides of the tunnel.

[0056] S3: Select two ZDY-6000 crawler-mounted directional drilling rigs for coal mines 4 and arrange them on both sides of the ear holes 7. Drilling is carried out in accordance with the designed axis 2 of the directional drilling rig, and the directional boreholes are arranged within a radius range of 7.5 m from the center of the tunnel section after turning.

[0057] S4: Before entering the fault zone, advanced detection work is carried out using technologies including the state of drilled rock slag, parameters of the drilling rig while drilling, and natural gamma detection technology. After entering the fault, detection is carried out using core drilling, parameters of the drilling rig while drilling, and natural gamma detection technology. First, implement the two exploration boreholes (the exploration boreholes also serve as grouting holes) in the crown arch. After the exploration boreholes (the first exploration borehole Z1 and the second exploration borehole Z2) reach the fault fracture zone, start the core drilling operation, and comprehensively study and judge the geological conditions of the fault fracture zone by combining the parameters of the drilling rig while drilling and natural gamma detection technology.

[0058] S5: If the surrounding rock of the fault is extremely fractured and poorly cemented, and the water inflow from the boreholes is relatively small, and it is judged that there is a risk of collapse of the surrounding rock of the fracture zone causing the TBM to get stuck and there is no risk of sudden gushing, use the two exploration boreholes (the first exploration borehole Z1 and the second exploration borehole Z2) in the crown arch for pre-treatment of consolidated grouting of the surrounding rock of the tunnel arch. The layout relationship of the grouting section in the crown arch, the tunnel excavation section 8 where the grouting intersects, the borehole diameter 9, and the grout diffusion diameter is as Figure 3 shown.

[0059] If the water return in the exploration boreholes suddenly increases, the flow rate and water pressure are monitored in real time at the orifice. If the water inflow shows no decreasing trend and the water gushing is under pressure, and it is judged that there is a greater risk of sudden gushing, while grouting operations are carried out in the two exploration boreholes (the first exploration borehole Z1 and the second exploration borehole Z2) in the crown arch, directional drilling and high-pressure grouting work of two supplementary boreholes (the first supplementary borehole Z3 and the second supplementary borehole Z4) are carried out synchronously at the invert arch to form a continuous and closed grouting curtain around the tunnel.

[0060] Use the reserved rock pillar of the TBM face from the boundary of the fault zone as the grout stop wall. The grouting method is all segmented progressive grouting. The hole-injection grouting is carried out by lowering the perforated pipe. The grouting materials are modified single-component cement slurry and cement-sodium silicate double-component slurry. The grouting pressure is determined according to the external water head (grouting pressure = 1.5 - 2 times the measured external water pressure at the location of the grouting section). The effective diffusion radius of the slurry is 8.0 m. The grout diffusion intersects to form an effective grouted solidified body within a certain radius range centered on the center of the tunnel section, so as to achieve one-time grouting reinforcement treatment of the crown arch or the periphery of the front fault fracture zone section of the tunnel. The layout relationship of the grouting section around the periphery, the tunnel excavation section 8 where the grouting intersects, the borehole diameter 9, and the grout diffusion diameter is as Figure 4 shown.

[0061] S6: After the grouting treatment is completed, a water pressure test is carried out to check the grouting effect. After passing the test (the post-grouting permeability in the grouting area < 5 Lu), the TBM normally advances through the fault fracture zone.

[0062] The above embodiments are merely illustrative examples of the technical solutions of the present invention. The present invention is not limited to what is described in the above embodiments, but is subject to the scope defined by the claims. Any modifications, supplements, or equivalent replacements made by those skilled in the art to which the present invention pertains based on this embodiment are within the scope protected by the claims of the present invention.

Claims

1. An in-tunnel parallel advanced exploration and treatment integrated disposal method for fault fracture zones in open TBM tunnels, characterized in that: It includes the following steps: S1: Determine the location of the fault fracture zone in front of the tunnel according to the geological exploration report, and calculate the mileage of the TBM working face in combination with the daily footage of TBM tunneling, the theoretical drilling speed of the drill rig, and the construction period of the pilot hole excavation, so as to complete the pilot hole excavation, directional drilling exploration and treatment before the TBM reaches the fault fracture zone; S2: When the distance between the TBM working face and the fault fracture zone is within a predetermined distance, excavate pilot holes on both side walls of the tunnel in the TBM equipment bridge area. The positions of the pilot holes are close to the TBM working face and meet the directional drilling deflection space; S3: Arrange directional drilling rigs in the two pilot holes, adopt an arc drilling form and use a gyroscope for positioning to reach the fault fracture zone in front of the tunnel working face; S4: Conduct advanced detection during the directional drilling process, analyze the detection data, and comprehensively evaluate the geological risk situation of the fault fracture zone; S5: When it is judged that there is a risk of TBM jamming due to the collapse of the surrounding rock in the front fracture zone of the TBM, consolidate the grouting of the surrounding rock of the tunnel arch; when it is judged that there is a risk of gushing, conduct curtain grouting on the surrounding rock of the tunnel circumference; S6: After the grouting is completed, test the grouting effect. After passing the test, continue the normal tunneling of the TBM and pass through the fault fracture zone.

2. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 1, wherein: In the step S1, the mileage of the TBM working face satisfies the following relationship: The construction period for the directional drilling rig to drill through and pass through the fault fracture zone is: ； The total time required for directional drilling exploration - treatment is: ； The time required for the TBM to pass through the distance D2 required for the directional drilling rig to deflect is: ； According to T TBM Greater than T 探查-治理 The requirement is that ; The relationship between the mileage of the working face and the starting mileage of the fault fracture zone: ； The mileage of the TBM working face needs to satisfy: ； In the formula, X1: the mileage of the working face; X2: the starting mileage of the fault fracture zone; D1: the distance between the TBM equipment bridge area and the TBM working face; D2: the distance required for the directional drilling rig to deflect; D3: the width of the fault fracture zone; V1: the tunneling speed of the TBM; V2: the theoretical drilling speed of the directional drilling rig in this formation; T TBM : The time required for the TBM to advance from the current mileage to before the fault fracture zone; T 探查-治理 : The total construction period for completing earhole construction, drill rig boring, and grouting treatment; T1: the construction period of the pilot hole construction; T2: the construction period for the drill rig to drill to the fault fracture zone; T3: the construction period for grouting treatment of the fault zone.

3. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 1, characterized in that: In the step S3, the directional drilling construction is completed within the range of 2 - 5 m outside the tunnel excavation contour line.

4. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 1 or 2 or 3, characterized in that: In the step S3, several exploration boreholes are constructed in the top arch using the two pilot holes, and the detection target area is within the range of 2 - 5 m outside the excavation contour line of the tunnel arch shoulder.

5. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 4, characterized in that: In the step S4, before entering the fault zone, advanced detection work is carried out by combining the state of the drilled cuttings, the parameters of the drill rig during drilling, and the natural gamma detector. After entering the fault, detection is carried out by combining core drilling, the parameters of the drill rig during drilling, and the natural gamma detector.

6. The in-tunnel parallel advanced exploration and treatment integrated disposal method for the fault fracture zone of the open TBM tunnel according to claim 5, wherein: The parameters of the drill rig during drilling include the torque, rotation speed, impact power of the drill rig, and the parameters of the drilling stroke.

7. The integrated treatment method for parallel advanced exploration and treatment inside the tunnel of the open TBM tunnel fault fracture zone according to claim 6, characterized in that: In the step S5, when it is determined that there is a risk of TBM jamming due to the collapse of the surrounding rock in the front fracture zone of the TBM, consolidate the grouting of the surrounding rock of the tunnel arch using the exploration boreholes in the top arch.

8. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 7, characterized in that: In the step S5, when it is determined that there is a risk of gushing, while conducting grouting operations in the exploration boreholes in the top arch, directional drilling and high - pressure grouting work of several supplementary boreholes are simultaneously carried out at the invert to conduct curtain grouting on the surrounding rock of the tunnel circumference.

9. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 8, characterized in that: In the step S5, the grouting method is the sectional progressive grouting. The reserved rock pillar of the TBM face away from the boundary of the fault zone is used as the grout stopping wall. The hole grouting is carried out by lowering the perforated pipe. The grouting materials are the modified single liquid cement slurry and the cement-sodium silicate double liquid slurry. The grouting pressure is 1.5 to 2 times of the measured external water pressure at the location of the grouting section. The effective diffusion radius of the slurry is 8 to 10 m. The grouting diffusion intersects to form an effective grouting reinforcement body within the diffusion radius with the center of the tunnel section as the center of the circle.

10. The integrated treatment method for parallel advanced exploration and treatment in the tunnel of the open TBM tunnel fault fracture zone according to claim 1 or 2 or 3, characterized in that: In the step S6, after the grouting is completed, the water pressure test is carried out to test the grouting effect. If the water permeability rate after grouting in the grouting area is < 5 Lu, it is judged as qualified.

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