Connection channel construction method

Abstract

The invention discloses a contact channel construction method, which relates to the technical field of tunnel construction, and comprises the following steps: freezing a preset construction area where a contact channel to be constructed is located and forming a current freezing barrier, and then controlling shield equipment to carry out tunneling operation on the current freezing barrier according to current tunneling parameters, and meanwhile, after tunneling is conducted by the preset length, segment ring installation and grouting operation are conducted, in the tunneling process, heat preservation is conducted on the current freezing barrier under the real-time freezing parameter condition, low-temperature heat preservation can be conducted on the construction area of the connecting channel, and collapse of surrounding rock of the connecting channel can be avoided. And finally, the steps of controlling the shield tunneling equipment to conduct tunneling operation on the current freezing barrier according to the current tunneling parameters in the preset construction area till the tunneling preset length is reached, and then conducting segment ring installation and grouting operation are repeatedly executed till a connection channel is formed through construction, continuous construction can be conducted, and the construction efficiency is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and particularly relates to a construction method for a connecting passage. Background Art

[0002] A connecting passage is usually a connecting passage between double-track tunnels or multi-track tunnels, and its functions include but are not limited to rescue passages, ventilation, drainage, and exhaust passages, etc. In the prior art, when constructing a connecting passage, usually the drill and blast method, the freeze drill and blast method or a small shield machine is used for shield construction. Although when using a small shield machine for shield construction, the shield construction of the connecting passage can be realized and the construction efficiency can be ensured, however, when constructing a tunnel in a water-rich or soft surrounding rock area, due to the existence of water-rich sand layers or geological bodies, whether using the drill and blast method or the shield method for construction, there are hidden dangers of collapse or gushing of the surrounding rock of the connecting passage, which not only causes the instability of the geological body and affects the buildings above the connecting passage, but also affects the construction efficiency. Summary of the Invention

[0003] The main object of the present invention is to propose a construction method for a connecting passage, aiming to solve the technical problem that in the prior art, due to the existence of water-rich sand layers or geological bodies, whether using the drill and blast method or the shield method for construction, there are hidden dangers of collapse or gushing of the surrounding rock of the connecting passage, which not only causes the instability of the geological body and affects the buildings above the connecting passage, but also affects the construction efficiency.

[0004] To achieve the above object, in a first aspect, a construction method for a connecting passage proposed by the present invention includes the following steps:

[0005] In a preset construction area, control the shield equipment to carry out tunneling operations on the current freezing barrier with the current tunneling parameters; wherein, the current freezing barrier is thermally insulated under real-time freezing parameter conditions;

[0006] After tunneling a preset length, carry out segment ring installation and grouting operations;

[0007] Repeat the steps of "in a preset construction area, control the shield equipment to carry out tunneling operations on the current freezing barrier with the current tunneling parameters" to "after tunneling a preset length, carry out segment ring installation and grouting operations" until the connecting passage is constructed.

[0008] In an embodiment, the step of "in a preset construction area, control the shield equipment to carry out tunneling operations on the current freezing barrier with the current tunneling parameters" includes:

[0009] In the preset construction area, carry out freezing operations on the geological body to be tunneled along the extension direction of the connecting passage to obtain the current freezing barrier;

[0010] Collect the current geological parameters of the current frozen barrier; wherein, the current geological parameters include the current temperature and current hardness of the current frozen barrier;

[0011] According to the current geological parameters, obtain the current tunneling parameters of the shield equipment during shield tunneling; wherein, the current shield parameters include the current thrust, current torque, and current tunneling speed;

[0012] Control the shield equipment to tunnel the current frozen barrier with the current tunneling parameters.

[0013] In one embodiment, the step of performing freezing operation on the geological body to be tunneled along the extension direction of the connecting passage in the preset construction area to obtain the current frozen barrier includes:

[0014] Install freezing equipment into the geological body to be tunneled along the extension direction in the preset construction area;

[0015] Use the freezing equipment to perform freezing operation on the geological body to be tunneled to obtain the current frozen barrier.

[0016] In one embodiment, the step of collecting the current geological parameters of the current frozen barrier includes:

[0017] Install data acquisition equipment on the current frozen barrier; wherein, the data acquisition equipment includes a temperature sensor, a core drill, and a rock hardness tester;

[0018] Collect the current geological parameters of the current frozen barrier through the data acquisition equipment.

[0019] In one embodiment, after the step of controlling the shield equipment to tunnel the current frozen barrier with the current tunneling parameters, it further includes:

[0020] Collect the real-time geological parameters of the current frozen barrier in real time;

[0021] According to the real-time geological parameters, obtain the real-time freezing control parameters during the tunneling operation of the shield equipment;

[0022] Control the shield equipment to perform freezing and heat preservation operation on the current frozen barrier according to the real-time freezing control parameters during the tunneling operation.

[0023] In one embodiment, before the step of controlling the shield equipment to perform freezing and heat preservation operation on the current frozen barrier according to the real-time freezing control parameters during the tunneling operation, it further includes:

[0024] Obtain the refrigerant injection parameters corresponding to the real-time freezing control parameters; wherein, the refrigerant injection parameters include the refrigerant injection volume and the injection speed.

[0025] In one embodiment, the step of controlling the shield equipment to perform the freezing and heat preservation operation on the current freezing barrier according to the real-time freezing control parameters during the tunneling operation includes:

[0026] Control the shield equipment to inject the refrigerant with the refrigerant injection parameters into the current freezing barrier according to the real-time freezing control parameters during the tunneling operation, so as to perform the freezing and heat preservation operation on the current freezing barrier.

[0027] In one embodiment, the step of installing the segment ring and grouting operation after tunneling the preset length includes:

[0028] After tunneling the preset length, perform segment assembly to form the segment ring;

[0029] Perform grouting operation in the area where the segment ring contacts the geological body.

[0030] In one embodiment, the step of performing segment assembly to form the segment ring after tunneling the preset length includes:

[0031] After tunneling the preset length until a ring of segment ring can be assembled, perform segment assembly to form the segment ring.

[0032] In one embodiment, after repeatedly executing the step of controlling the shield equipment to perform tunneling operation on the current freezing barrier with the current tunneling parameters in the preset construction area until the step of installing the segment ring and grouting operation after tunneling the preset length until the connection channel is constructed, the method further includes:

[0033] Perform grouting construction on the connection area between the portal of the connection channel and the existing tunnel.

[0034] When the technical solution of the present invention is in use, first, freezing operation is carried out on the preset construction area where the connection passage to be constructed is located to form the current freezing barrier. Next, the shield equipment is controlled to carry out tunneling operation on the current freezing barrier with the current tunneling parameters. At the same time, after tunneling a preset length, segment ring installation and grouting operation are carried out, so that the present invention can adopt the method combining shield and freezing to construct the connection passage. Meanwhile, during the tunneling process, the current freezing barrier is thermally insulated under the real-time freezing parameter conditions, which enables the present invention to carry out low-temperature thermal insulation on the construction area of the connection passage during specific implementation. Furthermore, the present invention can avoid the surrounding rock of the connection passage from collapsing and also prevent the geological body above the connection passage from becoming unstable. Finally, by repeatedly executing the steps of controlling the shield equipment to carry out tunneling operation on the current freezing barrier with the current tunneling parameters in the preset construction area until after tunneling a preset length, segment ring installation and grouting operation are carried out, until the connection passage is constructed, which enables the present invention to carry out continuous construction and ensures the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0036] Figure 1 It is a flowchart of the connection passage construction method provided by the present invention;

[0037] Figure 2 For Figure 1 it is a flowchart of step S100 exemplified in

[0038] Figure 3 For Figure 2 it is a flowchart of step S110 exemplified in

[0039] Figure 4 For Figure 2 it is a flowchart of step S120 exemplified in

[0040] Figure 5 For Figure 2 it is a flowchart of step S140 exemplified in

[0041] Figure 6 For Figure 1 it is a flowchart of step S200 exemplified in

[0042] Figure 7 It is a flowchart of some specific embodiments of the connection passage construction method exemplified by the present invention.

[0043] The realization, functional features and advantages of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0044] 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 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.

[0045] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0047] The present invention provides a construction method for a connection passage.

[0048] Please refer to Figures 1 to 7 , for the convenience of understanding, the construction method for a connection passage includes the following steps:

[0049] S100. In a preset construction area, control the shield equipment to carry out tunneling operations on the current freezing barrier with the current tunneling parameters; wherein, the current freezing barrier is thermally insulated under the real-time freezing parameter conditions.

[0050] Specifically, a current freezing barrier is established in the construction area of the connecting channel in advance. A series of freezing holes can be arranged along the construction range through drilling equipment, and refrigerant (such as liquid nitrogen or calcium chloride solution) is injected to freeze the stratum. The freezing process should adjust the amount of refrigerant and the circulation time according to the permeability and thermal conductivity of the stratum to ensure the formation and uniformity of the freezing barrier, so as to enhance the strength of the stratum and suppress water gushing and soil disturbance. When implementing shield tunneling, the tunneling parameters of the shield machine (such as cutter head speed, propulsion force, soil discharge speed, etc.) are controlled to ensure that the freezing barrier maintains its integrity. In order to prevent the freezing barrier from melting due to the heat of tunneling, the temperature changes of the freezing barrier are monitored in real time during the tunneling process (such as using buried temperature sensors) and the refrigerant is continuously replenished through the cooling system to maintain the effective thermal insulation of the freezing barrier.

[0051] S200: After the preset excavation length, the segment rings are installed and grouting operations are carried out.

[0052] When the shield machine has excavated to a preset length (such as 2m or 3m, which is usually longer than the length required to assemble a ring of segment rings), the machine is stopped to install the segment rings. The segment rings can be made of prefabricated reinforced concrete components, and the tightness of the splicing is achieved through precise alignment and mechanical locking during installation. Subsequently, grouting operations are carried out in the gaps between the segment rings and the surrounding strata, and slurry (such as cement slurry, clay-cement mixture or chemical slurry) is injected to fill the gaps and enhance the bonding between the segments and the strata. During the grouting process, a pressure monitoring device can be used to control the grouting pressure and flow in real time to ensure that the slurry is evenly filled without residual gaps.

[0053] S300, repeatedly executing the steps of controlling the shield equipment to excavate the current freezing barrier with current excavation parameters in the preset construction area until the preset excavation length is reached, and then performing segment ring installation and grouting operations until the connecting channel is formed through construction.

[0054] After each tunneling and segment installation, the cold barrier was re-insulated and the shield machine's tunneling parameters were adjusted to ensure smooth subsequent tunneling and stable surrounding rock. The status of the cold barrier and surrounding rock deformation were continuously monitored during tunneling (for example, using laser rangefinders or displacement monitoring devices). Based on this data, construction parameters (such as shield advance speed and grouting volume) were dynamically adjusted to adapt to changing geological conditions. Ultimately, through multiple iterations of construction, the connecting channel was successfully completed.

[0055] In this embodiment, first, freezing operations are performed on the preset construction area where the connection passage to be constructed is located to form the current freezing barrier. Next, the shield equipment is controlled to perform tunneling operations on the current freezing barrier with the current tunneling parameters. At the same time, after tunneling a preset length, segment ring installation and grouting operations are carried out. This enables the present invention to use a method combining shield tunneling and freezing for the construction of the connection passage. Meanwhile, during the tunneling process, the current freezing barrier is thermally insulated under the real-time freezing parameter conditions, which enables the present invention to perform low-temperature thermal insulation on the construction area of the connection passage during specific implementation. Furthermore, this enables the present invention to avoid the collapse of the surrounding rock of the connection passage and also prevents the instability of the geological body above the connection passage. Finally, by repeatedly executing the steps of controlling the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters in the preset construction area until after tunneling a preset length, segment ring installation and grouting operations are carried out, until the connection passage is constructed, which enables the present invention to carry out continuous construction and ensures the construction efficiency.

[0056] In one embodiment, step S100 includes:

[0057] S110. In the preset construction area, perform freezing operations on the geological body to be tunneled along the extension direction of the connection passage to obtain the current freezing barrier.

[0058] Specifically, freezing holes can be arranged along the extension direction of the connection passage in the preset construction area. The spacing of the freezing holes can be determined according to the water permeability of the geological body and the tunneling diameter. For example, the spacing of the freezing holes can be set to 0.8 meters to 1.2 meters. Refrigerant, such as liquid nitrogen or calcium chloride solution, is injected into the freezing holes to reduce the geological temperature in the construction area and gradually form a freezing barrier. To achieve uniform freezing, a phased injection strategy should be adopted. By systematically monitoring the temperature distribution and freezing depth during the freezing process, the flow rate and pressure of the injected refrigerant are adjusted at any time to ensure that the freezing barrier completely covers the passage area and reaches an appropriate hardness and thickness.

[0059] S120. Collect the current geological parameters of the current freezing barrier; wherein, the current geological parameters include the current temperature and current hardness of the current freezing barrier.

[0060] To monitor the characteristics of the freezing barrier in real time, multi-point temperature sensors and hardness measurement devices can be embedded in the freezing barrier to collect and record the temperature distribution status and hardness values of the current freezing barrier. The temperature data and hardness data of each point are collected once every 2 hours and transmitted to the monitoring center through a wireless module. During the formation stage of the freezing barrier, it should be ensured that the current geological parameters reach the preset thresholds (such as the temperature is lower than -10°C and the apparent hardness is higher than 30 MPa) to confirm that the freezing barrier can meet the engineering requirements for subsequent shield tunneling.

[0061] S130. Obtain the current tunneling parameters of the shield equipment during shield tunneling according to the current geological parameters; wherein, the current shield parameters include the current thrust, the current torque, and the current tunneling speed.

[0062] Based on the collected geological parameters of the freezing barrier, such as temperature, hardness, and permeability, appropriate shield tunneling parameters, including shield thrust, cutterhead torque, and tunneling speed, can be calculated with the help of an engineering database and a parameter matching model. Exemplarily, assuming that the apparent hardness of the freezing barrier is 35 MPa and the geological water content is 8%, the tunneling parameters can be set as follows: the shield thrust is 50 - 70 kN / m 2 , the cutterhead torque is 10 - 12 kN·m, and the tunneling speed is 1.5 - 2.0 m / h. Additionally, the operating load is monitored in real time through the sensors built in the shield equipment to ensure the dynamic matching of the parameters with the construction conditions.

[0063] S140. Control the shield equipment to tunnel the current freezing barrier with the current tunneling parameters.

[0064] After the freezing barrier meets the construction requirements, start the shield equipment for tunneling operations. Input the currently set tunneling parameters into the shield equipment through the control system and make dynamic adjustments in combination with the real-time monitoring feedback. During the entire tunneling process, the changes in the shield propulsion force and the cutterhead rotation speed should be monitored with emphasis to avoid problems such as local instability of the freezing barrier or ground settlement caused by improper parameters. The spoil generated during the tunneling process will be transported out of the construction area through an automatic conveying system to ensure the continuous excavation of the passage.

[0065] Through the precise setting of parameters and the dynamic control of the tunneling process, the coordinated action of the equipment with the freezing barrier and the surrounding geology can be achieved, thereby improving the safety and continuity of the passage construction and achieving the goal of efficient construction.

[0066] In one embodiment, step S110 includes:

[0067] S111. Install freezing equipment along the preset construction area and along the extension direction into the geological body to be tunneled.

[0068] Arrange freezing equipment in the preset construction area of the connection passage to fully freeze the geological body to be tunneled. Specifically, use drilling equipment to drill freezing holes in the geological body to be tunneled along the extension direction of the connection passage. The spacing and depth of the freezing holes can be adjusted according to the geological conditions. For example, when the area to be tunneled is sandy stratum, the spacing of the freezing holes can be set to 0.8 - 1.2 meters, and the depth is the full height of the tunneling section plus an additional 50 centimeters. Subsequently, insert freezing pipes or freezing cooling devices into the freezing holes. The outer wall of the freezing pipes is made of stainless steel and has good sealing performance to ensure that it can withstand the low-temperature operating environment of the freezing medium.

[0069] S112. Use the refrigeration equipment to perform refrigeration operations on the geological body to be tunnelled, so as to obtain the current refrigeration barrier.

[0070] After the refrigeration equipment is installed, the refrigeration operations on the geological body to be tunnelled are started. Specifically, the refrigeration operations can be carried out by continuously injecting low-temperature media, such as refrigerants with stable low-temperature characteristics like liquid nitrogen, freon or carbon dioxide, into the refrigeration pipes or cooling devices through the refrigeration system, and ensuring that the refrigerant circulation is leak-free. At the same time, monitor the temperature changes of the freezing holes to ensure that the freezing temperature of the area to be tunnelled meets the predetermined requirements. For example, control the temperature of the geological body below -15°C. The refrigeration operation time can be adjusted according to the formation conditions and is typically between 72 hours and 120 hours. After a covering freezing barrier has been formed as a whole in the area to be tunnelled, further supplement the refrigerant to maintain the stability of the current refrigeration barrier.

[0071] Through the refrigeration operations, a uniform and stable refrigeration barrier is formed in the geological body. This barrier can greatly improve the strength of the geological body, reduce the possibility of seepage or gushing, and provide safe and reliable surrounding rock conditions for shield tunnelling. In addition, due to the continuous supply of the low-temperature medium, the barrier can maintain its effectiveness for a long time.

[0072] In one embodiment, step S120 includes:

[0073] S121. Install data acquisition equipment on the current refrigeration barrier; wherein, the data acquisition equipment includes a temperature sensor, a core drill and a rock hardness tester.

[0074] After the refrigeration barrier is formed, data acquisition equipment needs to be installed on the refrigeration barrier to monitor the geological parameters of the refrigeration barrier. Specifically, first, plan the layout of the data acquisition points. Set monitoring sections along the direction of the connecting passage on the refrigeration barrier, with an interval of 5 - 10 meters between each section, and evenly arrange 4 - 8 monitoring points on each section in the circumferential direction.

[0075] It can be further explained that temperature data acquisition and core sampling operations can be carried out at each inspection point.

[0076] S122. Collect the current geological parameters of the current refrigeration barrier through the data acquisition equipment.

[0077] Use the installed data acquisition equipment to collect the geological parameters of the current refrigeration barrier at a predetermined time interval.

[0078] By systematically collecting geological parameters such as the temperature and hardness of the frozen barrier, the real-time state of the frozen barrier can be accurately grasped, and weak areas or uneven freezing areas can be detected in a timely manner. The construction management method based on the measured data improves the control ability of the quality of the frozen barrier, provides a reliable geological foundation for subsequent shield tunneling, and effectively avoids construction accidents caused by insufficient quality of the frozen barrier.

[0079] In one embodiment, after step S140, it further includes:

[0080] S141. Real-time collect the real-time geological parameters of the current frozen barrier.

[0081] During the formation of the frozen barrier, data acquisition devices (such as temperature sensors, rock hardness meters, etc.) configured on the current frozen barrier are used to collect real-time geological parameters.

[0082] S142. According to the real-time geological parameters, obtain the real-time freezing control parameters during the tunneling operation of the shield device.

[0083] Input the collected real-time geological parameters into the intelligent analysis system, and calculate the freezing control parameters suitable for the current construction environment through comprehensive analysis of these parameters.

[0084] S143. Control the shield device to perform freezing and heat preservation operations on the current frozen barrier according to the real-time freezing control parameters during the tunneling operation.

[0085] According to the analyzed freezing control parameters, adjust the freezing system to ensure that it can provide suitable environmental protection during shield operation.

[0086] Through the real-time adjustment of the computer control system, it can dynamically respond to environmental changes during the construction process, improve the adaptability and construction efficiency of the shield device, and at the same time minimize the engineering risks brought by the failure of the frozen barrier.

[0087] In one embodiment, before step S143, it further includes:

[0088] S144. Obtain the refrigerant injection parameters corresponding to the real-time freezing control parameters; wherein, the refrigerant injection parameters include the refrigerant injection volume and the injection speed.

[0089] Before adjusting the freezing system for heat preservation operation, it is necessary to accurately calculate the required refrigerant injection parameters according to the real-time freezing control parameters. In an exemplary embodiment, the refrigerant injection parameters can be calculated in the following specific manner.

[0090] Based on the real-time collected temperature distribution data of the freezing barrier and combined with the heat conduction model, calculate the cooling capacity required to maintain or adjust the state of the freezing barrier. For areas where the temperature sensor shows values close to the critical value (such as above -10°C), increase the refrigerant injection volume by 20%; for areas where the temperature is stable below -15°C, the conventional injection volume can be maintained or slightly reduced by 5% - 10% to save energy consumption. The calculation formula for the refrigerant injection volume is:

[0091] Q = mCK × ΔT

[0092] Where Q is the required cooling capacity (kJ), m is the mass of the surrounding rock (kg), C is the specific heat capacity of the surrounding rock (kJ / kg·°C), ΔT is the target temperature change value (°C), and K is the safety factor (usually taken as 1.2 - 1.5).

[0093] Specifically, for sandy soil layers, the typical injection volume is 150 - 200 L / m 3 / day; for clay layers, the typical injection volume is 100 - 150 L / m 3 / day; for strata with a water content exceeding 30%, the injection volume should be increased to 220 - 250 L / m 3 / day.

[0094] Next, select a suitable refrigerant injection speed according to the formation characteristics and the current state of the freezing barrier. Too fast an injection speed may lead to uneven freezing or excessive pipeline pressure, while too slow a speed will delay the formation of the freezing effect.

[0095] For newly formed frozen areas, the initial injection speed is set at 15 - 20 L / min. After 2 - 3 hours, it is gradually reduced to a stable speed of 10 - 15 L / min; for areas that have reached the target temperature, the maintenance speed is 5 - 10 L / min, which is only used to compensate for heat loss.

[0096] In addition, the injection speed also needs to be adjusted according to the layout density of the freezing pipes and the groundwater flow rate. For dense areas where the spacing between freezing pipes is less than 1.0 m, the injection speed can be reduced by 10% - 15%; while in areas where the groundwater flow rate exceeds 0.5 m / d, the injection speed should be increased by 15% - 20% to offset the heat carried away by the water flow.

[0097] Finally, select the appropriate type of refrigerant according to geological conditions and temperature requirements. For critical areas that require rapid freezing, liquid nitrogen (boiling point -196°C) can be selected as the refrigerant, and the injection speed is controlled at 25 - 30 L / min; for freezing areas that need to be maintained for a long time, calcium chloride solution (concentration 25% - 30%, freezing point about -55°C) can be selected, and the injection speed is 15 - 20 L / min; for shallow areas with low requirements for freezing depth, ethylene glycol solution (concentration 20% - 25%, freezing point about -15°C) can be used, and the injection speed is controlled at 10 - 15 L / min.

[0098] By precisely calculating and controlling the injection volume and injection speed of the refrigerant, the freezing barrier can be formed more uniformly and stably, avoiding energy waste and construction risks caused by insufficient freezing or over-freezing in traditional shield construction. At the same time, by differentially adjusting the injection parameters according to the real-time status of different areas, the response speed and adaptability of the freezing system are improved, ensuring that the shield equipment operates under optimal conditions.

[0099] In some other feasible embodiments, for complex working conditions with multiple geological layers, a refrigerant injection strategy of zoning and layering can be adopted:

[0100] Divide the construction area into several functional areas according to geological characteristics, and set up independent refrigerant supply systems and control units for each functional area. For example, for the water-bearing sand layer area, the refrigerant injection volume is set at 220 - 250 L / m 3 / day, and the injection speed is 18 - 22 L / min; for the clay layer area, the injection volume is set at 110 - 130 L / m 3 / day, and the injection speed is 8 - 12 L / min.

[0101] Improve the freezing efficiency through intermittent high-flow injection. The specific operation is that each high-flow (25 - 30 L / min) injection lasts for 15 - 20 minutes, then pauses for 5 - 10 minutes, and then proceeds to the next cycle. In this way, the same freezing effect as continuous injection can be achieved while reducing the total injection volume by 10% - 15%.

[0102] Dynamically adjust the refrigerant injection parameters of each area according to the three-dimensional temperature field monitoring data. When the temperature in a certain area drops 3°C below the target value, automatically reduce the injection speed of this area by 20%; when the temperature rises 2°C above the target value, restore the original injection speed and temporarily increase it by 10% until the temperature stabilizes again.

[0103] In one embodiment, step S143 includes:

[0104] Control the shield equipment to inject refrigerant with the refrigerant injection parameters into the current freezing barrier according to the real-time freezing control parameters during the tunneling operation, so as to perform freezing and heat preservation operations on the current freezing barrier.

[0105] Specifically, first, continuously collect the temperature data of the surrounding rock and the freezing barrier, as well as real-time environmental parameters such as the underground water flow velocity and direction through the temperature sensors and related monitoring equipment distributed in the shield construction area. Determine the specific parameters of refrigerant injection, including the injection volume and injection speed, according to the real-time freezing control parameters. Select a suitable type of refrigerant to meet the operation requirements according to the geology of the shield construction area and the state of the freezing barrier.

[0106] In one embodiment, step S200 includes:

[0107] S210. After tunneling the preset length, perform segment assembly to form the segment ring.

[0108] The preset length is usually determined according to the engineering design requirements to ensure that the length of each segment ring is appropriate and the overall structure stability is achieved.

[0109] During segment assembly, first place the precast segments in the tunnel that has been tunneled in sequence, and fix each segment by means of bolt connection or buckle connection to ensure their close fit.

[0110] During the assembly process, use precision instruments such as laser locators for real-time monitoring to ensure the roundness of the segment ring and the accurate positioning of the axis to meet the requirements of tunnel design.

[0111] S220. Perform grouting operation in the area where the segment ring contacts the geological body.

[0112] Perform grouting operation in the area where the segment ring contacts the geological body to achieve structural sealing and support. The specific steps are as follows:

[0113] After the assembly of each segment ring is completed, immediately perform grouting in the area of the gap between its outer side and the geological body. The grouting material can be selected from cement slurry, chemical slurry, etc., and adjusted according to the geological conditions.

[0114] The grouting pressure and speed need to be adjusted in combination with the actual geological pressure. Usually, the pressure is controlled at 0.2 - 0.5 MPa, and the grouting speed is 20 - 30 L / min to ensure that the slurry can fully fill the gap and solidify quickly.

[0115] The grouting material of the grouting operation quickly solidifies after reacting with water to form a sealing layer, enhancing the bearing capacity and anti-seepage performance of the segment ring structure, and is especially suitable for complex conditions such as high groundwater level and loose soil layers.

[0116] In one embodiment, step S210 includes:

[0117] After tunneling the preset length until a segment ring can be assembled, segment assembly is carried out to form the segment ring.

[0118] The preset length refers to the distance that the shield machine advances forward from the end of the previous segment ring until the next segment can be installed. According to the actual requirements of the tunnel project, this preset length is usually 1.5 - 2.0 meters, which is consistent with the width of the standard segment ring. During tunneling, a high-precision displacement sensor is used to monitor the tunneling distance of the shield machine in real time. When the monitored value reaches 98% of the preset length, the system automatically sends a prompt signal to remind the operator to prepare to enter the segment assembly stage.

[0119] In one embodiment, after step S300, the method further includes:

[0120] S400. Conduct grouting construction on the connection area between the portal of the connecting passage and the existing tunnel.

[0121] Specifically, before grouting construction, it is necessary to carry out cleaning and sealing pretreatment on the connection area between the portal of the connecting passage and the existing tunnel to ensure the smooth progress of subsequent construction. Clean the soil, gravel and sundries on the surface of the portal connection area, thoroughly wash the structure surface with a high-pressure water gun, and keep the surface moist. Use appropriate filling materials (such as dry hard cement mortar) to block larger cracks or holes to prevent the slurry from leaking during grouting, which may have an adverse impact on the working environment and the structure.

[0122] In this embodiment, through grouting construction, the gaps in the connection area between the portal and the existing tunnel can be effectively filled to form a uniform support body, preventing structural deformation and uneven settlement problems caused by the existence of fissures or pores.

[0123] The grouting operation can block the infiltration of groundwater and ensure the watertightness of the connection between the portal and the tunnel. Even in a highly permeable formation or an environment with high water pressure, long-term anti-seepage can be achieved.

[0124] Through the grouting operation, it is not only applicable to general stable geological conditions, but also can efficiently handle complex situations such as sand layers, faults, and water-rich conditions, enhancing the applicability and flexibility of the construction method.

[0125] The above is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A construction method for a connection passage, characterized in that The method includes the following steps: In a preset construction area, control the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters; wherein, the current freezing barrier is thermally insulated under the real-time freezing parameter conditions; After tunneling a preset length, perform segment ring installation and grouting operations; Repeat the steps of "In a preset construction area, control the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters" to "After tunneling a preset length, perform segment ring installation and grouting operations" until the connection passage is constructed.

2. The construction method of the connection passage according to claim 1, characterized in that The step of "In a preset construction area, control the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters" includes: In the preset construction area, perform freezing operations on the geological body to be tunneled along the extension direction of the connection passage to obtain the current freezing barrier; Collect the current geological parameters of the current freezing barrier; wherein, the current geological parameters include the current temperature and current hardness of the current freezing barrier; According to the current geological parameters, obtain the current tunneling parameters of the shield equipment during shield tunneling operations; wherein, the current shield parameters include the current thrust, current torque, and current tunneling speed; Control the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters.

3. The construction method of the connection passage according to claim 2, characterized in that The step of "In the preset construction area, perform freezing operations on the geological body to be tunneled along the extension direction of the connection passage to obtain the current freezing barrier" includes: Install freezing equipment into the geological body to be tunneled along the extension direction in the preset construction area; Use the freezing equipment to perform freezing operations on the geological body to be tunneled to obtain the current freezing barrier.

4. The construction method of the connection passage according to claim 3, wherein, The step of "Collect the current geological parameters of the current freezing barrier" includes: Install data acquisition equipment on the current freezing barrier; wherein, the data acquisition equipment includes a temperature sensor, a core drill, and a rock hardness tester; Collect the current geological parameters of the current freezing barrier through the data acquisition equipment.

5. The construction method of the connecting passage according to claim 2, characterized in that, After the step of "Control the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters", it further includes: Real-time collect the real-time geological parameters of the current freezing barrier; According to the real-time geological parameters, obtain the real-time freezing control parameters during the tunneling operations of the shield equipment; Control the shield equipment to perform freezing and heat preservation operations on the current freezing barrier according to the real-time freezing control parameters during tunneling operations.

6. The construction method of the connecting passage according to claim 5, characterized in that, Before the step of "Control the shield equipment to perform freezing and heat preservation operations on the current freezing barrier according to the real-time freezing control parameters during tunneling operations", it further includes: Obtain the refrigerant injection parameters corresponding to the real-time freezing control parameters; wherein, the refrigerant injection parameters include the refrigerant injection volume and injection speed.

7. The construction method of the connecting passage according to claim 6, wherein, The step of "Control the shield equipment to perform freezing and heat preservation operations on the current freezing barrier according to the real-time freezing control parameters during tunneling operations" includes: Control the shield equipment to inject refrigerant with the refrigerant injection parameters into the current freezing barrier according to the real-time freezing control parameters during the tunneling operation, so as to perform freezing and heat preservation operations on the current freezing barrier.

8. The construction method of the connecting passage according to any one of claims 1 to 7, characterized in that, The step of installing the segment ring and grouting after tunneling a preset length includes: After tunneling the preset length, assemble the segments to form the segment ring; Perform grouting operations in the area where the segment ring contacts the geological body.

9. The construction method of the connecting passage according to claim 8, characterized in that, The step of assembling the segments to form the segment ring after tunneling the preset length includes: After tunneling the preset length to the point where a ring of segment ring can be assembled, assemble the segments to form the segment ring.

10. The construction method of the connecting passage according to any one of claims 1 to 7, characterized in that, After repeatedly executing the step of controlling the shield equipment to perform tunneling operations on the current freezing barrier with the current tunneling parameters in the preset construction area until the step of installing the segment ring and grouting after tunneling the preset length is completed until the connection channel is constructed, the method further includes: Perform grouting construction on the connection area between the portal of the connection channel and the existing tunnel.

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