River undercrossing construction risk identification and early warning system and method for shield

Abstract

The invention discloses a construction risk identification and early warning system and method for a shield machine to pass through a river downwards. The method comprises the following steps that an advanced geological detection module assigns a geological risk value W1 according to a detected geological type; the water area monitoring module assigns W2 according to the patrolled abnormal vortex and the falling speed of the water level; a shield tunnel monitoring module monitors vertical displacement / horizontal displacement / radial convergence and in-hole water seepage monitoring values of a tunnel structure, and assigns a shield tunnel risk value W3; the tunneling monitoring unit assigns the shield tunneling risk value W4 according to the shield tunneling cutterhead actual pressure and cutterhead actual torque; the system controls an early warning module to calculate a W value according to W1, W2, W3, W4 and related formulas, and engineering early warning is carried out; and the emergency processing module carries out risk analysis, identification and emergency processing on the early warning result. According to the method, various risks can be pre-judged, the accuracy of risk identification is improved, the safety of shield construction is guaranteed, and the overall method is simple, efficient, easy to implement and wide in applicability.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, and in particular to a risk identification and early warning system and method for TBM tunneling under rivers. Background Technology

[0002] With the rapid development of urban construction, urban rail transit has greatly shortened citizens' commuting time in cities, and to some extent, shortened urban spatial distances, accelerating urban integration. As subways are gradually developed into suburban and peripheral areas, tunnels inevitably need to cross underwater areas such as rivers. Shield tunneling in these underwater areas carries a significant risk of water seepage, necessitating strengthened risk identification and early warning systems to mitigate construction risks. Shield tunneling is a complex system engineering project, requiring the integration of hydrological, geological, and shield tunneling factors. Shield tunneling under rivers is an even more complex undertaking with greater construction risks. The impact of tunneling on the strata cannot be quickly reflected using methods similar to ground-based monitoring, thus posing greater challenges to risk identification and early warning in this condition, and posing a greater challenge to the accuracy of risk identification and early warning. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a shield tunneling river crossing construction risk identification and early warning system that can monitor multi-dimensional factors in a comprehensive and three-dimensional manner, with high accuracy and wide applicability, as well as a risk identification and early warning method.

[0004] This invention is achieved through the following technical solution: A risk identification and early warning system for shield tunneling under rivers includes an advanced geological exploration module, a water area monitoring module, a shield tunnel monitoring module, a shield tunneling module, a system control module, and an emergency early warning module; The advanced geological exploration module includes several advanced geological drilling rigs installed on the tunnel boring machine, which are used to explore the geology in front of the tunnel boring machine face and output geological risk values ​​based on the explored geological conditions. The water area monitoring module is used to monitor the water area through which the shield tunnel passes and output the water area risk value based on the monitoring results. The monitoring content includes the water area eddy current situation and the water level situation. The shield tunnel monitoring module is used to monitor the shield tunnel that has been constructed and output the risk value of the shield tunnel based on the monitoring results. The monitoring content includes the vertical displacement of the tunnel structure, the horizontal displacement of the tunnel structure, the radial convergence value of the tunnel structure, and the water seepage situation inside the tunnel. The shield tunneling module includes a tunneling monitoring unit, which is used to monitor the shield tunneling construction during shield tunneling and output shield tunneling risk values ​​based on the monitoring results. The monitoring content includes the actual pressure and actual torque of the shield tunneling cutterhead. The system control and early warning module is used to receive data from the advanced geological exploration module, water area monitoring module, shield tunnel monitoring module and shield tunneling module, and to issue risk warnings based on the received data; The emergency response module is used to identify risks based on the risk warning results from the system control and early warning module, and to regulate the tunnel boring machine module and take emergency measures based on the risk identification results.

[0005] A method for risk identification and early warning during shield tunneling under rivers, employing the aforementioned risk identification and early warning system for shield tunneling under rivers, the method comprising the following steps: S1. The advanced geological exploration module sets the geological risk value W1 to 0-1. It determines the geological type based on the data from the advanced geological drilling rig, and then assigns a value to the geological risk value W1 based on the geological type. The more permeable and prone to collapse the geology, the higher the value of W1 will be. S2. The water area monitoring module sets the water area risk value W2 to 0-1. The water area within the set range that the shield tunnel passes through is inspected regularly by personnel to check for abnormal whirlpools. If any are found, W2 is assigned a value of 1. A water level gauge is set in the water area within the set range, the water level is monitored regularly, the rate of water level drop v is calculated, and W2 is assigned a value based on the rate of water level drop v. S3, the shield tunnel monitoring module monitors the constructed shield tunnel. The monitoring content includes the vertical displacement monitoring value A1 of the tunnel structure, the horizontal displacement monitoring value A2 of the tunnel structure, the radial convergence monitoring value A3 of the tunnel structure, and the seepage monitoring value inside the tunnel. Based on the monitoring results, the risk value W3 of the shield tunnel is assigned. The seepage monitoring value inside the tunnel is the number of seepage points that appear every 50m along the length of the shield tunnel. S4. The tunneling monitoring unit monitors the shield tunneling construction. The monitoring content includes the actual pressure and actual torque of the shield tunneling cutterhead, and assigns a value to the shield tunneling risk value W4 based on the monitoring results. The steps S1, S2, S3, and S4 mentioned above have no temporal order; S5. The system control and early warning module calculates the W value based on the received W1, W2, W3, and W4 according to the formula W = (a1·W1 + a2·W2 + a3·W3 + a4·W4) / 10. If W is greater than the set value r (e.g., 0.8), an early warning is issued. Where a1 is the weight of the geological risk value W1, 0 ≤ a1 ≤ 10; a2 is the weight of the water risk value W2, 0 ≤ a2 ≤ 10; a3 is the weight of the shield tunnel risk value W3, 0 ≤ a3 ≤ 10; a4 is the weight of the shield tunneling risk value W4, 0 ≤ a4 ≤ 10; a1 + a2 + a3 + a4 = 10. S6. The emergency response module performs risk analysis based on the early warning results from the system control module. First, it determines whether any of the parameters W1, W2, W3, and W4 have a value greater than the set value r (e.g., 0.8). If so, it identifies the risk for the corresponding module and performs emergency response based on the identification results until W ≤ the set value r, thus meeting the conditions for tunnel boring machine passage. If W1, W2, W3, and W4 are all not greater than the set value r, but the comprehensive parameter W is greater than the set value r, a rectification analysis is required. The value of r is then increased only after there is no substantial risk.

[0006] Furthermore, in step S1, the method for determining the geological type based on the data from borehole exploration by the advanced geological drilling rig is as follows: The shield of the tunnel boring machine is reserved with construction holes for advanced geological drilling rigs. The construction holes include several radial holes and several horizontal holes. Radial holes are used for drilling and core sampling. The adapter plate with advanced geological drilling rigs is installed on the suction cup of the segment assembly machine. During drilling operations, the drilling positions are arranged according to the abnormal areas revealed by the previous exploration and the construction conditions. The drilling positions are adjusted by rotating the assembly machine. A combination of impact drilling and rotary coring is used. Impact drilling is used in the part where the inclined drill rod has not yet penetrated into the working face, while rotary coring is used in the remaining part after the working face. Impact drilling is used in general sections, while rotary coring is used in special sections. During drilling, the lithology, rock strength, rock mass integrity, and groundwater development ahead of the drilling face are detected by the sound of the core tube, drilling speed and its changes, core samples, stuck drill bits, and drill rod vibration.

[0007] Furthermore, in step S1, the method for assigning a geological risk value W1 based on the geological type is as follows: If the geological type is a highly permeable stratum (sand layer, strongly weathered rock layer), then W1 is assigned a value of 0.8; if the geological type is a soft upper layer and hard lower layer (lower medium and slightly weathered rock layer + upper sand layer, silty soil, etc.), then W1 is assigned a value of 0.9; if the geological type is a conventional full-section soil layer, then W1 is assigned a value of 0.5; if the geological type is a full-section medium and slightly weathered rock layer, then W1 is assigned a value of 0.3; for other types of geological layers, the value can be assigned according to their similarity to the above geological types, and for those between two adjacent geological types, the midpoint between the two values ​​is taken.

[0008] Furthermore, in step S2, the method for assigning a value to W2 based on the rate of water level decline v is as follows: If it is in the non-flood season and the water level drop rate v > 2 m / d, then assign W2 the value of 0.5; if it is in the non-flood season and the water level drop rate 2 m / d ≤ v ≤ 4 m / d, then assign W2 the value of 0.8; if it is in the non-flood season and the water level drop rate v > 4 m / d, then assign W2 the value of 1; if the water level drop rate of the river surface v < 2 m / d and there is no abnormal vortex, then assign W2 the value of 0; if the water level is in the rising state, then also assign W2 the value of 0.

[0009] Furthermore, in step S3, the total station or precise level is used to monitor the vertical displacement value A1 and the horizontal displacement value A2 of the tunnel structure, and the convergence meter is used to monitor the radial convergence value A3 of the tunnel structure. The monitoring section spacing is 10 - 15 m; when the distance L between the cutter head of the shield at the front excavation face and the water area is L ≤ 3D, the measurement frequency is 1 - 2 times / d; when the distance 3D < L ≤ 8D between the cutter head of the shield at the front excavation face and the water area, the measurement frequency is 1 time / (1 - 2)d; when the distance L between the cutter head of the shield at the front excavation face and the water area is L > 8D, the measurement frequency is 1 time / (3 - 5)d, where D is the outer diameter of the shield.

[0010] Furthermore, in step S3, the method for assigning the risk value W3 of the shield tunnel according to the monitoring results is as follows: Calculate the ratios M1, M2, and M3 of the vertical displacement value A1, the horizontal displacement value A2, and the radial convergence value A3 of the tunnel structure to the vertical displacement control value D1, the horizontal displacement control value D2, and the radial convergence control value D of the tunnel structure respectively. M1 = A1 / D1, M2 = A2 / D2, M3 = A3 / D3; Assign a value to M4 according to the in-tunnel water seepage monitoring value. If the in-tunnel water seepage monitoring value > 10, then assign M4 the value of 0.8; if 5 ≤ in-tunnel water seepage monitoring value ≤ 10, then assign M4 the value of 0.5; if the in-tunnel water seepage monitoring value < 5, then assign M4 the value of 0.3; Calculate the value of M according to the formula M = (b1·M1 + b2·M2 + b3·M3 + b4·M4) / 10; where b1, b2, b3, and b4 are the weights of M1, M2, M3, and M4 respectively, 0 ≤ b1 ≤ 10, 0 ≤ b2 ≤ 10, 0 ≤ b3 ≤ 10, 0 ≤ b4 ≤ 10, and b1 + b2 + b3 + b4 = 10; Assign the risk value W3 of the shield tunnel according to the value of M. If M ≤ 0.6, then assign W3 the value of 0.6; if 0.6 < M < 0.8, then assign W3 the value of 0.7; if 0.​​

[0012] Furthermore, in step S4, the method for assigning a shield tunneling risk value W4 according to the monitoring results is as follows: Calculate the ratios K1 and K2 of the actual cutterhead pressure and the actual cutterhead torque to the cutterhead pressure control value and the cutterhead torque control value respectively; calculate the K value according to the formula K = (c1·K1 + c2·K2) / 10; where c1 and c2 are the weights of K1 and K2, 0 ≤ c1 ≤ 10, 0 ≤ c2 ≤ 10, and c1 + c2 = 10; it can be set that c1 = 5 and c2 = 5; Assign a value to the shield tunneling risk value W4 according to the K value. If K ≤ 0.6, then assign W4 the value of 0.6; if 0.6 < K < 0.8, then assign W4 the value of 0.7; if 0.8 ≤ K < 1, then assign W4 the value of 0.8; if K ≥ 1, then assign W4 the value of 1.

[0013] Furthermore, in step S6, if W1 is greater than the set value r, the shield stops construction, and advanced grouting reinforcement or ground reinforcement is carried out on the poor formation of the front heading face. After the reinforcement construction is completed, the geological risk value W1 is assigned again according to the method in step S1 until W1 ≤ the set value r; If W2 is greater than the set value r, the shield stops construction, and further check whether there is abnormal water seepage inside the segment. If so, immediately stop construction and organize an emergency evacuation, grout and plug the water seepage point. After the water seepage point stops leaking, repair it until the water seepage stops; continuously strengthen the monitoring, and do well in synchronous grouting and secondary grouting. When necessary, carry out in - tunnel grouting reinforcement to reinforce the formation above the tunnel arch; If W3 is greater than the set value r, the shield stops construction, and further check whether there is abnormal water seepage inside the segment. If so, immediately stop construction and organize an emergency evacuation, grout and plug the water seepage point. After the water seepage point stops leaking, repair it until the water seepage stops; analyze the monitoring data of the shield tunnel, continuously pay attention to the deformation of the segment, hold a special demonstration meeting to analyze the reasons for excessive deformation, and take reinforcement measures including internal support until the deformation no longer develops and W3 ≤ the set value r; If W4 is greater than the set value r, adjust the shield tunneling parameters and the face pressure according to the monitored actual cutterhead pressure and the actual cutterhead torque of the shield tunneling module, and continuously pay attention to the shield tunneling construction parameters. For the situation where the parameters are continuously abnormal, stop the shield tunneling, check the cutterhead by opening the chamber to eliminate the problem of abnormal tunneling parameters caused by serious cutterhead wear until W4 ≤ the set value r.

[0014] This invention incorporates an advanced geological exploration module, a water area monitoring module, a shield tunnel monitoring module, a shield tunneling module, a system control module, and an emergency early warning module. Through a systematic monitoring system, it comprehensively assesses the likelihood and severity of risks by considering multiple factors such as the geology of the shield tunnel face, changes in river water level, tunnel structural deformation, and tunnel cutting. This allows for the prediction of various risks as much as possible, improving the accuracy of risk identification during shield tunneling under rivers. It enables early warning during construction and allows for the implementation of appropriate emergency measures, ensuring the safety of shield tunneling. Furthermore, the overall method is simple, efficient, and easy to implement. It can be flexibly adapted to different working conditions by adjusting the weights and values ​​of various factors according to specific construction scenarios, making it widely applicable. Attached Figure Description

[0015] Figure 1 This is a framework structure diagram of an embodiment of the present invention. Detailed Implementation

[0016] A risk identification and early warning system for shield tunneling under rivers, such as Figure 1 As shown, it includes an advanced geological exploration module, a water area monitoring module, a shield tunnel monitoring module, a shield tunneling module, a system control module, and an emergency early warning module; The advanced geological exploration module includes several advanced geological drilling rigs installed on the tunnel boring machine, which are used to drill and explore the geology in front of the tunnel boring machine face and output geological risk values ​​based on the geological conditions detected. The water area monitoring module is used to monitor the water area through which the shield tunnel passes and output the water area risk value based on the monitoring results. The monitoring content includes the water area eddy current situation and the water level situation. The shield tunnel monitoring module is used to monitor the shield tunnel that has been constructed and output the risk value of the shield tunnel based on the monitoring results. The monitoring content includes the vertical displacement of the tunnel structure, the horizontal displacement of the tunnel structure, the radial convergence value of the tunnel structure, and the water seepage situation inside the tunnel. The shield tunneling module includes a tunneling monitoring unit, which is used to monitor the shield tunneling construction during shield tunneling and output shield tunneling risk values ​​based on the monitoring results. The monitoring content includes the actual pressure and actual torque of the shield tunneling cutterhead. The system control and early warning module is used to receive data from the advanced geological exploration module, water area monitoring module, shield tunnel monitoring module and shield tunneling module, and to issue risk warnings based on the received data; The emergency response module is used to identify risks based on the risk warning results from the system control and early warning module, and to regulate the tunnel boring machine module and take emergency measures based on the risk identification results.

[0017] A method for risk identification and early warning during shield tunneling under rivers, employing the aforementioned risk identification and early warning system for shield tunneling under rivers, the method comprising the following steps: S1. The advanced geological exploration module sets the geological risk value W1 to 0-1. It determines the geological type based on the data from the advanced geological drilling rig's borehole exploration, and then assigns a value to the geological risk value W1 according to the geological type. The more permeable and prone to collapse the geology, the higher the value of W1.

[0018] The advanced geological drilling positions are set on the tunnel boring machine (TBM). The principle is to utilize the TBM's built-in advanced drilling positions to explore the geological conditions ahead at the tunnel face. This method belongs to the drilling exploration technology and can detect changes in lithology ahead of the tunnel face, such as irregularities, discontinuities, faults, and fracture zones. The exploration method is as follows: Advanced geological drilling positions are pre-reserved at the shield of the TBM. These positions include several radial and several horizontal positions, typically 15 radial positions and 3 horizontal positions. Core sampling is performed using the radial positions at an 11° drilling angle. The core sampling rods are approximately 50-70cm long, with an outer diameter of 75mm and an inner diameter of 50mm. Each rod is approximately 1.5m long. An adapter plate with the drilling rig is installed on the suction cup of the segment assembly machine. During drilling operations, the drilling positions are arranged according to the abnormal areas revealed in the previous exploration and the construction conditions, and the drilling positions are adjusted by rotating the assembly machine. Due to the slow drilling speed, advanced geological drilling can employ a combination of percussion drilling and rotary core drilling. Percussion drilling is used in sections where the drill pipe has not yet penetrated the face, while rotary core drilling is used in the remaining sections beyond the face. Percussion drilling is used in general sections, while rotary core drilling is used in special sections. During drilling, the lithology, rock strength, rock mass integrity, and groundwater development ahead of the face can be determined by observing the sound of the core tube, drilling speed and its changes, core samples, stuck drill bits, and drill pipe vibration.

[0019] Using radial advance geological drilling to change the need for horizontal drilling at the tunnel face can reduce the impact on the tunnel boring machine, maintain the stability of the tunnel face, and obtain the geological conditions along the borehole depth in front of the tunnel face through drilling results, so as to realize the identification of the geological conditions in front of the excavation face and provide a basis for safe and accurate tunnel construction.

[0020] Specifically, the method for assigning a geological risk value W1 based on geological type is as follows: If the geological type is a highly permeable formation (sand layer, strongly weathered rock layer), then assign W1 the value of 0.8; if the geological type is a soft upper and hard lower formation (lower medium and slightly weathered rock layer + upper sand layer, silt soil, etc.), then assign W1 the value of 0.9. The upper and lower formations are bounded by the tunnel waist. The upper part is above the tunnel waist, and the lower part is below the tunnel waist; if the geological type is a conventional full-section soil layer, then assign W1 the value of 0.5; if the geological type is a full-section medium and slightly weathered rock layer, then assign W1 the value of 0.3; for other types of geological layers, the value can be assigned according to their similarity to the above geological types. For those between two adjacent geological types, take the intermediate value of the two.

[0021] S2. The water area monitoring module sets the water area risk value W2 to 0 - 1. Manually conduct regular inspections on the water area within the set range of the shield tunneling to check for abnormal vortices. If any, assign W2 the value of 1; set water level gauges in the water area within the set range, regularly monitor the water level, calculate the water level drop rate v, and assign a value to W2 based on the water level drop rate v. The one-time burial depth of the tunnel is h, and the general inspection range is the plane within h outside the tunnel structure edge.

[0022] Specifically, the method of assigning a value to W2 based on the water level drop rate v is as follows: If it is in the non-flood season and the water level drop rate v > 2m / d, then assign W2 the value of 0.5; if it is in the non-flood season and the water level drop rate 2m / d ≤ v ≤ 4 m / d, then assign W2 the value of 0.8; if it is in the non-flood season and the water level drop rate v > 4m / d, then assign W2 the value of 1; if the water level drop rate v < 2m / d in the river surface and there are no abnormal vortices, then assign W2 the value of 0; if the water level is in the rising state, then the value of W2 is also assigned 0.

[0023] S3. The shield tunnel monitoring module monitors the constructed shield tunnel. The monitoring contents include the vertical displacement monitoring value A1 of the tunnel structure, the horizontal displacement monitoring value A2 of the tunnel structure, the radial convergence monitoring value A3 of the tunnel structure, and the in-tunnel water seepage monitoring value, and assigns a value to the shield tunnel risk value W3 based on the monitoring results.

[0024] The vertical displacement monitoring value A1 and the horizontal displacement monitoring value A2 of the tunnel structure can be monitored using a total station or a precision level. The radial convergence monitoring value A3 of the tunnel structure can be measured using a convergence meter. The monitoring section spacing is 10 - 15m. When the distance L between the shield cutterhead of the front excavation face and the water area (river) is L ≤ 3D, the measurement frequency is 1 - 2 times / d; when the distance 3D < L ≤ 8D between the shield cutterhead of the front excavation face and the water area (river), the measurement frequency is 1 time / (1 - 2)d; when the distance L between the shield cutterhead of the front excavation face and the water area (river) is L > 8D, the measurement frequency is 1 time / (3 - 5)d, where D is the outer diameter of the shield.

[0025] Specifically, the method for assigning a risk value W3 to the shield tunnel according to the monitoring results is as follows: (1) Calculate the ratios M1, M2, and M3 of the monitored values A1 of the vertical displacement of the tunnel structure, A2 of the horizontal displacement of the tunnel structure, and A3 of the radial convergence of the tunnel structure to the control values D1 of the vertical displacement of the tunnel structure, D2 of the horizontal displacement of the tunnel structure, and D3 of the radial convergence of the tunnel structure, respectively. M1 = A1 / D1, M2 = A2 / D2, M3 = A3 / D3.

[0026] In some construction scenarios, before formal construction, according to the specifications, the maximum allowable displacement of the vertical displacement (i.e., the control value D1 of the vertical displacement of the tunnel structure) is 10 mm, the maximum horizontal displacement (i.e., the control value D2 of the horizontal displacement of the tunnel structure) is 5 mm, and the maximum radial deformation (i.e., the control value D3 of the radial convergence of the tunnel structure) is 10 mm. M1, M2, and M3 are obtained by comparing the actual construction monitoring with these maximum values allowed by the specifications, and are generally less than 1.

[0027] (2) Assign a value to M4 according to the monitored value of the water seepage in the tunnel. If the monitored value of the water seepage in the tunnel > 10, then assign M4 the value of 0.8; if 5 ≤ the monitored value of the water seepage in the tunnel ≤ 10, then assign M4 the value of 0.5; if the monitored value of the water seepage in the tunnel < 5, then assign M4 the value of 0.3. The monitored value of the water seepage in the tunnel refers to the number of leakage points that appear every 50 m in the tunnel length direction.

[0028] (3) Calculate the value of M according to the formula M = (b1·M1 + b2·M2 + b3·M3 + b4·M4) / 10; where b1, b2, b3, and b4 are the weights of M1, M2, M3, and M4 respectively, 0 ≤ b1 ≤ 10, 0 ≤ b2 ≤ 10, 0 ≤ b3 ≤ 10, 0 ≤ b4 ≤ 10, and b1 + b2 + b3 + b4 = 10. b1, b2, b3, and b4 are set according to the actual situation. In some embodiments, it can be set that: b1 = 3, b2 = 3, b3 = 3, b4 = 1.

[0029] (4) Assign a value to the shield tunnel risk value W3 according to the value of M. If M ≤ 0.6, then assign W3 the value of 0.6; if 0.6 < M < 0.8, then assign W3 the value of 0.7; if 0.8 ≤ M < 1, then assign W3 the value of 0.8; if M ≥ 1, then assign W3 the value of 1.

[0030] S4. The tunneling monitoring unit monitors the shield tunneling construction, and the monitoring contents include the actual pressure of the shield tunneling cutterhead and the actual torque of the cutterhead, and assigns a value to the shield tunneling risk value W4 according to the monitoring results.

[0031] Specifically, the method for assigning a risk value W4 to the shield tunneling according to the monitoring results is as follows: (1) Calculate the ratios K1 and K2 of the actual cutterhead pressure and the actual cutterhead torque to the cutterhead pressure control value and the cutterhead torque control value respectively; calculate the K value according to the formula K = (c1·K1 + c2·K2) / 10; where c1 and c2 are the weights of K1 and K2, 0 ≤ c1 ≤ 10, 0 ≤ c2 ≤ 10, and c1 + c2 = 10. In some embodiments, c1 = 5 and c2 = 5 can be set.

[0032] (2) Assign a value to the shield tunneling risk value W4 according to the K value. If K ≤ 0.6, assign W4 the value 0.6; if 0.6 < K < 0.8, assign W4 the value 0.7; if 0.8 ≤ K < 1, assign W4 the value 0.8; if K ≥ 1, assign W4 the value 1.

[0033] There is no sequence of time for the above steps S1, S2, S3, and S4; S5. The system control warning module calculates the W value according to the received W1, W2, W3, and W4 according to the formula W = (a1·W1 + a2·W2 + a3·W3 + a4·W4) / 10; if W is greater than the set value r (such as 0.8), a warning is issued; where a1 is the weight of the geological risk value W1, 0 ≤ a1 ≤ 10; a2 is the weight of the water area risk value W2, 0 ≤ a2 ≤ 10; a3 is the weight of the shield tunnel risk value W3, 0 ≤ a3 ≤ 10; a4 is the weight of the shield tunneling risk value W4, 0 ≤ a4 ≤ 10; a1 + a2 + a3 + a4 = 10. a1, a2, a3, a4, and r can be set according to the actual situation. In some of these embodiments, it can be set that: a1 = 1, a2 = 4, a3 = 4, a4 = 1, and r = 0.8.

[0034] S6. The emergency treatment module analyzes the risks according to the warning result of the system control module. First, judge whether there is a situation where the values of the parameters W1, W2, W3, and W4 are greater than the set value r (such as 0.8). If so, perform risk identification on the module corresponding to the corresponding parameter, and perform emergency treatment according to the identification result until W ≤ the set value r, reaching the shield passing condition; if none of the parameters W1, W2, W3, and W4 are greater than the set value r, but the comprehensive parameter W is greater than the set value r, then rectification analysis needs to be carried out. After there is no substantial risk, the r value is increased, and subsequent normal construction is carried out.

[0035] Specifically, if W1 is greater than the set value r, it means that the soil layer data in front of the detected shield is abnormal, then the shield stops construction, and advanced grouting reinforcement or ground reinforcement is carried out on the poor ground in front of the heading face. After the reinforcement construction is completed, the geological risk value W1 is assigned again according to the method in step S1 until W1 ≤ the set value r; If W2 is greater than the set value r, it indicates an abnormal situation in the shield tunnel area. The abnormal water level (abnormal drop) may be caused by segment damage, which needs to be investigated in time. The shield tunneling should be stopped, and the internal leakage of the segments should be further checked. If there is any abnormal leakage, construction should be stopped immediately, emergency evacuation should be organized, and the leakage points should be grouted to plug the leaks. After the leakage points are plugged, repairs should be carried out until the leakage stops. Monitoring should be continuously strengthened, and synchronous grouting and secondary grouting should be carried out. If necessary, in-tunnel grouting reinforcement should be carried out to reinforce the strata above the tunnel arch. If W3 is greater than the set value r, it indicates that the monitoring data of the shield tunnel is abnormal. The shield tunneling will be stopped, and the internal leakage of the segments will be further checked. If there is any abnormal leakage, construction will be stopped immediately, an emergency evacuation will be organized, and the leakage points will be grouted to plug the leaks. After the leakage points are plugged, they will be repaired until the leakage stops. The monitoring data of the shield tunnel will be analyzed, the deformation of the segments will be continuously monitored, a special demonstration meeting will be held to analyze the cause of excessive deformation, and reinforcement measures, including internal support, will be taken until the deformation stops developing. W3 ≤ set value r. If W4 is greater than the set value r, it indicates that the tunnel boring machine (TBM) tunneling parameters are abnormal. The TBM tunneling module will then adjust the TBM tunneling parameters and face pressure based on the monitored actual cutterhead pressure and torque. The TBM tunneling parameters will be continuously monitored. If the parameters remain abnormal, the TBM tunneling will be stopped, and the cutterhead will be inspected by opening the tunnel chamber to rule out the problem of abnormal tunneling parameters caused by severe cutterhead wear, until W4 ≤ the set value r.

[0036] The above detailed description is a specific description of feasible embodiments of the present invention. These embodiments are not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included in the patent scope of this case.

Claims

1. A risk identification and early warning system for shield tunneling under rivers, characterized in that, It includes advanced geological exploration modules, water area monitoring modules, shield tunnel monitoring modules, shield tunneling modules, system control modules, and emergency early warning modules; The advanced geological exploration module includes several advanced geological drilling rigs installed on the tunnel boring machine, which are used to drill and explore the geology in front of the tunnel boring machine face and output geological risk values ​​based on the geological conditions detected. The water area monitoring module is used to monitor the water area through which the shield tunnel passes and output the water area risk value based on the monitoring results. The monitoring content includes the water area eddy current situation and the water level situation. The shield tunnel monitoring module is used to monitor the shield tunnel that has been constructed and output the risk value of the shield tunnel based on the monitoring results. The monitoring content includes the vertical displacement of the tunnel structure, the horizontal displacement of the tunnel structure, the radial convergence value of the tunnel structure, and the water seepage situation inside the tunnel. The shield tunneling module includes a tunneling monitoring unit, which is used to monitor the shield tunneling construction during shield tunneling and output shield tunneling risk values ​​based on the monitoring results. The monitoring content includes the actual pressure and actual torque of the shield tunneling cutterhead. The system control and early warning module is used to receive data from the advanced geological exploration module, water area monitoring module, shield tunnel monitoring module and shield tunneling module, and to issue risk warnings based on the received data; The emergency response module is used to identify risks based on the risk warning results from the system control and early warning module, and to regulate the tunnel boring machine module and take emergency measures based on the risk identification results.

2. A method for risk identification and early warning during shield tunneling under rivers, characterized in that, The method of using the shield tunneling river crossing risk identification and early warning system as described in claim 1 includes the following steps: S1. The advanced geological exploration module sets the geological risk value W1 to 0-1. It determines the geological type based on the data from the advanced geological drilling rig's borehole exploration, and then assigns a value to the geological risk value W1 based on the geological type. The more permeable and prone to collapse the geology, the higher the value of W1 will be. S2. The water area monitoring module sets the water area risk value W2 to 0-1. The water area within the set range that the shield tunnel passes through is inspected regularly by personnel to check for abnormal whirlpools. If any are found, W2 is assigned a value of 1. A water level gauge is set in the water area within the set range, the water level is monitored regularly, the rate of water level drop v is calculated, and W2 is assigned a value based on the rate of water level drop v. S3, the shield tunnel monitoring module monitors the constructed shield tunnel. The monitoring content includes the vertical displacement monitoring value A1 of the tunnel structure, the horizontal displacement monitoring value A2 of the tunnel structure, the radial convergence monitoring value A3 of the tunnel structure, and the seepage monitoring value inside the tunnel. Based on the monitoring results, the risk value W3 of the shield tunnel is assigned. The seepage monitoring value inside the tunnel is the number of seepage points that appear every 50m along the length of the shield tunnel. S4. The tunneling monitoring unit monitors the shield tunneling construction. The monitoring content includes the actual pressure and actual torque of the shield tunneling cutterhead, and assigns a value to the shield tunneling risk value W4 based on the monitoring results. The steps S1, S2, S3, and S4 mentioned above have no temporal order; S5. The system control and early warning module calculates the W value based on the received W1, W2, W3, and W4 according to the formula W = (a1·W1 + a2·W2 + a3·W3 + a4·W4) / 10. If W is greater than the set value r, an early warning is issued. Where a1 is the weight of the geological risk value W1, 0 ≤ a1 ≤ 10; a2 is the weight of the water risk value W2, 0 ≤ a2 ≤ 10; a3 is the weight of the shield tunnel risk value W3, 0 ≤ a3 ≤ 10; a4 is the weight of the shield tunneling risk value W4, 0 ≤ a4 ≤ 10; a1 + a2 + a3 + a4 = 10. S6. The emergency response module performs risk analysis based on the early warning results from the system control module. First, it determines whether any of the parameters W1, W2, W3, and W4 have values ​​greater than the set value r. If so, it identifies the risk for the corresponding module and performs emergency response based on the identification results until W ≤ the set value r, thus meeting the conditions for tunnel boring machine passage. If W1, W2, W3, and W4 are all not greater than the set value r, but the comprehensive parameter W is greater than the set value r, a rectification analysis is required. The value of r is then increased only after there is no substantial risk.

3. The method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S1, the method for determining the geological type based on the data from borehole exploration by the advanced geological drilling rig is as follows: The shield of the tunnel boring machine is reserved with construction holes for advanced geological drilling rigs. The construction holes include several radial holes and several horizontal holes. Radial holes are used for drilling and core sampling. The adapter plate with advanced geological drilling rigs is installed on the suction cup of the segment assembly machine. During drilling operations, the drilling positions are arranged according to the abnormal areas revealed by the previous exploration and the construction conditions. The drilling positions are adjusted by rotating the assembly machine. A combination of impact drilling and rotary coring is used. Impact drilling is used in the part where the inclined drill rod has not yet penetrated into the working face, while rotary coring is used in the remaining part after the working face. Impact drilling is used in general sections, while rotary coring is used in special sections. During drilling, the lithology, rock strength, rock mass integrity, and groundwater development ahead of the drilling face are detected by the sound of the core tube, drilling speed and its changes, core samples, stuck drill bits, and drill rod vibration.

4. The method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S1, the method for assigning a geological risk value W1 based on the geological type is as follows: If the geological type is a highly permeable stratum, then W1 is assigned a value of 0.8; if the geological type is a soft upper stratum and a hard lower stratum, then W1 is assigned a value of 0.9; if the geological type is a conventional full-section soil layer, then W1 is assigned a value of 0.5; if the geological type is a full-section moderately weathered rock layer, then W1 is assigned a value of 0.

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5. The method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S2, the method for assigning a value to W2 based on the rate of water level drop v is as follows: If it is not the flood season and the rate of water level drop v > 2 m / d, then W2 is assigned a value of 0.5; if it is not the flood season and the rate of water level drop 2 m / d ≤ v ≤ 4 m / d, then W2 is assigned a value of 0.8; if it is not the flood season and the rate of water level drop v > 4 m / d, then W2 is assigned a value of 1; if the rate of water level drop v < 2 m / d and there are no abnormal whirlpools, then W2 is assigned a value of 0; if the water level is rising, then W2 is assigned a value of 0.

6. The method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S3, a total station or a precise level is used to monitor the vertical displacement value A1 and the horizontal displacement value A2 of the tunnel structure, and a convergence meter is used to monitor the radial convergence value A3 of the tunnel structure. The monitoring section spacing is 10 - 15 m. When the distance L between the cutter head of the shield at the front excavation face and the water area is L ≤ 3D, the measurement frequency is 1 - 2 times / d. When the distance 3D < L ≤ 8D between the cutter head of the shield at the front excavation face and the water area, the measurement frequency is 1 time / (1 - 2)d. When the distance L between the cutter head of the shield at the front excavation face and the water area is L > 8D, the measurement frequency is 1 time / (3 - 5)d, where D is the outer diameter of the shield.

7. The method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S3, the method for assigning a value to the shield tunnel risk value W3 according to the monitoring results is as follows: Calculate the ratios M1, M2, and M3 of the vertical displacement value A1 of the tunnel structure, the horizontal displacement value A2 of the tunnel structure, and the radial convergence value A3 of the tunnel structure to the vertical displacement control value D1 of the tunnel structure, the horizontal displacement control value D2 of the tunnel structure, and the radial convergence control value D3 of the tunnel structure respectively. M1 = A1 / D1, M2 = A2 / D2, M3 = A3 / D3. Assign a value to M4 according to the in - tunnel water seepage monitoring value. If the in - tunnel water seepage monitoring value > 10, then assign M4 the value 0.

8. If 5 ≤ in - tunnel water seepage monitoring value ≤ 10, then assign M4 the value 0.

5. If the in - tunnel water seepage monitoring value < 5, then assign M4 the value 0.

3. Calculate the M value according to the formula M = (b1·M1 + b2·M2 + b3·M3 + b4·M4) / 10. Here, b1, b2, b3, and b4 are the weights of M1, M2, M3, and M4 respectively, 0 ≤ b1 ≤ 10, 0 ≤ b2 ≤ 10, 0 ≤ b3 ≤ 10, 0 ≤ b4 ≤ 10, and b1 + b2 + b3 + b4 = 10. Assign a value to the shield tunnel risk value W3 according to the M value. If M ≤ 0.6, then assign W3 the value 0.

6. If 0.6 < M < 0.8, then assign W3 the value 0.

7. If 0.8 ≤ M < 1, then assign W3 the value 0.

8. If M ≥ 1, then assign W3 the value 1.

8. The method for risk identification and early warning during shield tunneling under rivers according to claim 7, characterized in that, b1 = 3, b2 = 3, b3 = 3, b4 = 1; In step S5, a1 = 1, a2 = 2, a3 = 2, a4 = 1, r = 0.

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9. A method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S4, the method for assigning a value to the shield tunneling risk value W4 according to the monitoring results is as follows: Calculate the ratios K1 and K2 of the actual cutter head pressure and the actual cutter head torque to the cutter head pressure control value and the cutter head torque control value respectively. Calculate the K value according to the formula K = (c1·K1 + c2·K2) / 10. Here, c1 and c2 are the weights of K1 and K2 respectively, 0 ≤ c1 ≤ 10, 0 ≤ c2 ≤ 10, and c1 + c2 = 10. Assign a value to the shield tunneling risk value W4 according to the K value. If K ≤ 0.6, then assign W4 the value 0.

6. If 0.6 < K < 0.8, then assign W4 the value 0.

7. If 0.8 ≤ K < 1, then assign W4 the value 0.

8. If K ≥ 1, then assign W4 the value 1.

10. A method for risk identification and early warning during shield tunneling under rivers according to claim 2, characterized in that, In step S6, if W1 is greater than the set value r, the tunnel boring machine stops construction and advanced grouting or ground reinforcement is carried out on the unfavorable strata at the face ahead. After the reinforcement is completed, the geological risk value W1 is assigned a value according to the method in step S1 until W1 ≤ the set value r. If W2 is greater than the set value r, the tunnel boring machine will stop construction and further check whether there is any abnormal water seepage inside the tunnel segment. If so, construction will be stopped immediately and an emergency evacuation will be organized. Grouting will be carried out to plug the seepage point. After the seepage point is stopped, repairs will be carried out until the seepage stops. Monitoring will be continuously strengthened and synchronous grouting and secondary grouting will be carried out. If necessary, in-tunnel grouting reinforcement will be carried out to reinforce the strata above the tunnel arch. If W3 is greater than the set value r, the tunnel boring machine (TBM) will stop construction and further check whether there is any abnormal water seepage inside the tunnel segments. If so, construction will be stopped immediately and an emergency evacuation will be organized. Grouting will be carried out to seal the seepage points. After the seepage points are stopped, repairs will be carried out until the seepage stops. The monitoring data of the TBM tunnel will be analyzed, and the deformation of the tunnel segments will be continuously monitored. A special demonstration meeting will be held to analyze the cause of excessive deformation and take reinforcement measures, including internal support, until the deformation stops developing. W3 ≤ set value r. If W4 is greater than the set value r, the shield tunneling module will adjust the shield tunneling parameters and face pressure based on the monitored actual cutterhead pressure and actual cutterhead torque, and continuously monitor the shield tunneling construction parameters. If the parameters are continuously abnormal, shield tunneling will be stopped, and the cutterhead will be inspected by opening the chamber to eliminate the problem of abnormal tunneling parameters caused by severe cutterhead wear, until W4 ≤ the set value r.

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