Construction method for subway shield section contact channel in water-rich soft stratum

Abstract

The invention relates to the technical field of shield section contact channel construction, and provides a subway shield section contact channel construction method used in a water-rich soft stratum, which comprises the following steps: S1, preparation work before construction: before construction, carrying out detailed geological investigation on a project, knowing the distribution condition of the stratum and the condition of underground water, and according to the investigation result, carrying out the construction of the underground water; formulating a detailed construction scheme and an emergency plan; s2, site arrangement and equipment selection: arranging temporary facilities in the construction area, and selecting a proper shield tunneling machine and auxiliary equipment according to geological conditions and construction requirements; and S3, soil body reinforcement is conducted, specifically, before construction, reinforcement treatment is conducted on the soil body of the connection channel. The stability and the bearing capacity of the stratum can be improved by reinforcing the soil body in the water-rich soft stratum, and the construction safety and quality are guaranteed and the construction efficiency is improved by monitoring the deformation condition of the stratum and selecting and adjusting the shield tunneling machine according to the geological conditions and the construction requirements.

Description

Technical Field

[0001] The invention relates to the technical field of shield section communication channel construction, in particular to a method for constructing a subway shield section communication channel in a water-rich soft stratum. Background Art

[0002] Water-rich soft strata refer to strata that contain a large amount of water in the soil or rock and have poor mechanical properties. Such strata are usually composed of soil or rock with high water content, large porosity, and loose particle structure. Water-rich soft strata often bring a series of problems and challenges in underground engineering, such as stratum settlement, water gushing, and slippage. At present, in underground projects such as subway shield tunneling, the existence of water-rich soft strata will increase the difficulty and risk of construction, and connecting passages need to be built between different sections of subway shield tunnels to achieve the connectivity and operation efficiency of subway lines.

[0003] The original construction method of the connecting channel was mining construction. Procedures such as jet grouting or freezing reinforcement have high requirements for the stratum, and the reinforcement results have a great impact on the mining excavation construction; the excavation process has high requirements for the support structure; the safety risk is relatively large during manual excavation; and the construction period is relatively long. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for constructing a connecting channel between subway shield sections in water-rich and soft strata, which solves the problems that the original connecting channel construction method has high requirements on the strata, its reinforcement results cannot adapt to mining excavation construction, and the excavation safety risks are relatively large and the construction period is long.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for constructing a subway shield tunnel section communication channel in a water-rich soft stratum, comprising the following steps: S1. Preparatory work before construction: Before construction, conduct a detailed geological survey of the project to understand the distribution of strata and the status of groundwater, and formulate a detailed construction plan and emergency plan based on the survey results; S2. Site layout and equipment selection: arrange temporary facilities in the construction area and select appropriate shield machines and auxiliary equipment according to geological conditions and construction requirements; S3. Soil reinforcement: Before construction, the soil of the connecting channel is reinforced, and the reinforcement depth is determined according to geological conditions and design requirements; S4. Shield machine positioning and commissioning: transport the shield machine to the construction site for installation and commissioning, and adjust various parameters of the shield machine according to geological conditions and construction requirements to ensure that it meets the construction needs; S5. Excavation of communication channel: Use a shield machine to excavate the communication channel; S6. Lining construction: After the excavation is completed, lining construction is carried out; S7, connection section construction: after the lining is completed, the connection section with the interval tunnel is constructed. The height and angle of the connection section are controlled and adjusted according to the design requirements; S8. Equipment dismantling and site cleaning: After the construction is completed, the shield machine and auxiliary equipment will be dismantled, and the construction site will be cleaned and restored.

[0006] Preferably, the reinforcement method used for soil reinforcement in step S3 is any one of freezing method construction, high-pressure grouting method, micropile reinforcement, curtain method construction, and pipe jacking method construction.

[0007] Preferably, the temporary settings in step S2 include a construction platform, a material yard, and a mixing station.

[0008] Preferably, the specific steps of excavating the communication channel in step S5 are: S5-1. Use a shield machine to excavate the communication channel, and control the advancement speed and excavation volume of the shield machine during the excavation process; S5-2. Closely monitor the deformation of the strata during the excavation process; S5-3. If the ground is deformed during the excavation process, timely measures must be taken to reinforce and treat it.

[0009] Preferably, the specific steps of monitoring in step S5-2 are: S5-21, monitoring the settlement of the ground surface points on the left and right lines of the section tunnel and the settlement of the ground surface points on the profile; S5-22, monitoring of tunnel convergence, tunnel arch bottom settlement, and arch top settlement during pipe jacking; S5-23. It is necessary to inspect the surface twice a day and inside the tunnel once a day, and adjust the frequency according to the size of the settlement.

[0010] Preferably, the specific steps of lining construction in step S6 are: S6-1. Preparation work: Before lining construction, prepare the required materials, equipment and construction plan; S6-2, Formwork construction: According to the design requirements, install the steel bars required for lining in the formwork. The arrangement of the steel bars must meet the requirements of structural strength and stability; S6-3, Concrete pouring: Pour the concrete into the formwork, control the pouring speed and uniformity, and at the same time, ensure that the concrete fits the steel bars fully to prevent the formation of gaps and cracks; S6-4. Curing treatment: Curing treatment is carried out on the newly poured concrete to ensure its full hardening and strength development.

[0011] Preferably, the lining in step S6 is reinforced concrete lining.

[0012] Preferably, the method for constructing the connection section in step S7 is selected from one of cast-in-place concrete and assembled pipe segments.

[0013] The present invention provides a method for constructing a connecting channel between shield tunnel sections in water-rich and soft strata of a subway. It has the following beneficial effects: The present invention can improve the stability and bearing capacity of the stratum by reinforcing the soil in the water-rich soft stratum, reduce the possibility of stratum settlement and deformation, and ensure construction safety and quality.

[0014] The present invention ensures construction safety and quality as well as stability of the geological environment by monitoring the deformation of the stratum and taking measures to reinforce and treat the stratum during the excavation and lining construction process.

[0015] The invention can effectively improve construction efficiency and quality and reduce difficulties and problems during construction by selecting and adjusting the shield machine according to geological conditions and construction requirements.

[0016] The present invention can ensure the smooth connection between the connecting channel and the interval tunnel by controlling and adjusting the height and angle of the connecting section according to the design requirements, and adopts reinforced concrete lining in the lining construction and cast-in-place concrete or assembled pipe segments in the connecting section construction. The methods can be selected according to the specific situation to improve the adaptability and flexibility of the construction. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example:

[0018] The embodiment of the present invention provides a method for constructing a subway shield tunnel section communication channel in a water-rich soft stratum, comprising the following steps: S1. Preparation work before construction: Before construction, conduct a detailed geological survey of the project to understand the distribution of the strata and the status of groundwater, and formulate a detailed construction plan and emergency plan based on the survey results to effectively improve the safety of construction. Through detailed geological surveys and groundwater status surveys, the formulation of construction plans and emergency plans can identify and evaluate potential geological risks in advance, take corresponding construction measures, reduce the probability of accidents and disasters, and improve construction safety; S2. Site layout and equipment selection: Temporary facilities are arranged in the construction area. According to the geological conditions and construction requirements, the temporary facilities are reasonably arranged and corresponding measures are taken to reduce land use and resource waste. Appropriate shield machines and auxiliary equipment are selected. By selecting appropriate shield machines and auxiliary equipment, they can be adjusted and optimized according to the geological conditions and construction requirements, so as to improve construction efficiency and quality, shorten the construction period, reduce construction costs, and reduce difficulties and problems during construction. S3. Soil reinforcement: Before construction, the soil of the connecting channel is reinforced. The reinforcement depth is determined according to geological conditions and design requirements. Appropriate soil reinforcement methods, such as freezing construction, high-pressure grouting, micro-pile reinforcement, curtain construction, and pipe jacking construction, can improve the stability and bearing capacity of the stratum, reduce the risk of stratum settlement and deformation, and ensure construction safety and long-term stability of the tunnel; S4. Shield machine positioning and commissioning: Transport the shield machine to the construction site for installation and commissioning, and adjust the various parameters of the shield machine according to geological conditions and construction requirements to ensure that it meets the needs of construction. The selection and adjustment of the shield machine according to geological conditions and construction requirements can effectively improve construction efficiency and quality and reduce difficulties and problems during construction; S5. Excavation of communication channels: Use a shield machine to excavate the communication channels, which has the ability to advance quickly and operate continuously. Compared with traditional manual excavation methods, the use of a shield machine can significantly shorten the construction period and improve construction efficiency. The shield machine has a precise control system and automated operation, which can ensure the accuracy and stability of excavation, reduce excavation errors and stratum damage, and thus improve construction quality. At the same time, the shield machine can reduce environmental pollution such as noise, vibration and dust during the excavation process, and has less impact on surrounding residents and the environment, which is conducive to protecting the safety and comfort of the surrounding environment. The operation and control of the shield machine is carried out in a closed control room, which reduces the risk of workers directly contacting the underground working environment and provides a safer working environment. At the same time, during the excavation process, real-time monitoring can be provided. It is equipped with various sensors and monitoring devices, which can monitor parameters such as stratum deformation and soil pressure during the excavation process in real time, discover and solve problems in a timely manner, and ensure the safety and stability of construction. S6. Lining construction: After the excavation is completed, lining construction is carried out; S7. Connection section construction: After the lining is completed, the connection section with the interval tunnel is constructed. The height and angle of the connection section are controlled and adjusted according to the design requirements. The connection section construction realizes structural continuity, improves structural stability, ensures smooth flow of fluid, ensures traffic comfort, optimizes traffic flow and improves the overall quality of the project, which helps to ensure the safe operation of the tunnel system and the long-term sustainable development of the project. By controlling and adjusting the height and angle of the connection section according to the design requirements, the smooth connection between the connecting channel and the interval tunnel can be guaranteed. In addition, the use of reinforced concrete lining in lining construction and cast-in-place concrete or assembled pipe segments in connection section construction can be selected according to specific conditions to improve the adaptability and flexibility of construction. S8. Equipment dismantling and site cleaning: After the construction is completed, the shield machine and auxiliary equipment will be dismantled, and the construction site will be cleaned and restored to protect the integrity and ecological balance of the surrounding environment.

[0019] In step S3, the reinforcement method used for soil reinforcement can be any one of freezing method construction, high-pressure grouting method, micro-pile reinforcement, curtain method construction, and jacking method construction. Freezing method construction: by injecting coolant around the soil, the soil is frozen to form a frozen body, thereby improving the strength and stability of the soil. In water-rich soft strata, the freezing method can effectively prevent stratum deformation and water seepage, and ensure construction safety; High-pressure grouting method: by injecting high-pressure cement slurry into the soil, a solid soil-slurry complex is formed to increase the strength and stability of the soil. This method can effectively prevent stratum deformation and water seepage, and is suitable for construction in water-rich soft strata; Micro-pile reinforcement: by injecting high-pressure cement slurry into the soil, a solid soil-slurry complex is formed, and the strength and stability of the soil is increased. This method can effectively prevent stratum deformation and water seepage, and is suitable for construction in water-rich soft strata; Drill holes and pour reinforced concrete to form micro piles, which increase the bearing capacity and stability of the soil. In water-rich soft strata, micro piles can effectively improve the bearing capacity and stability of the strata and prevent deformation and water seepage of the strata. Curtain method construction: By drilling holes in the soil and injecting cement slurry, a curtain body is formed to increase the strength and stability of the soil. In water-rich soft strata, the curtain method can effectively prevent deformation and water seepage of the strata and ensure construction safety. Pipe jacking method construction: Through the use of pipe jacking machinery to drill holes and install steel pipes, a pipe jacking body is formed to increase the strength and stability of the soil. In water-rich soft strata, the pipe jacking method can effectively avoid damage and disturbance to the strata and ensure construction safety.

[0020] The temporary settings in step S2 include construction platforms, material yards, and mixing stations, which help reduce the distance and time of material transportation and reduce construction costs.

[0021] The specific steps of communication channel mining in step S5 are: S5-1. Use a shield machine to excavate the communication channel. Control the advancement speed and excavation volume of the shield machine during the excavation process. Using a shield machine to excavate the communication channel is an efficient and relatively safe method. The shield machine has an automated control system that can control the advancement speed and excavation volume to ensure the stability of the construction. During the excavation process, the shield machine advances through soil cutting and thrust, and the excavated soil is sent out of the shield machine through a conveying system. It is fully enclosed to achieve structural safety throughout the construction process. Controlling the advancement speed and excavation volume of the shield machine is to avoid excessive advancement leading to ground collapse or excessive excavation volume causing unnecessary trouble; S5-2. Closely monitor the deformation of the stratum during the excavation process. Monitoring the deformation of the stratum can timely discover and evaluate the stability of the stratum. If the stratum has abnormal deformation, appropriate measures can be taken to ensure the safety of the construction; S5-3. If the ground is deformed during the excavation process, timely measures should be taken to reinforce and treat it, which can ensure the continuous progress of construction and the stability of the ground. Micro-reinforcement methods are adopted, mainly cutting portals and special structural designs. The grouting range is 3.0m outside the excavation line of the tunnel arch and side walls, and about 2.0m outside the bottom excavation line. The reinforcement range is small and the ground interference is low, which can prevent further deformation or collapse of the ground and ensure the smooth progress of construction and the safety of the tunnel. Taking measures to reinforce and treat can prevent further deformation or collapse of the ground and ensure the smooth progress of construction and the safety of the tunnel.

[0022] The specific steps of monitoring in step S5-2 are: S5-21. Monitoring the settlement of the left and right lines of the section tunnel is mainly to evaluate the deformation of the surface. Sectional surface settlement monitoring refers to selecting some specific locations on the surface and measuring their settlement to obtain the surface settlement data of the entire section tunnel profile. S5-22. Monitoring the convergence of the tunnel, the settlement of the tunnel arch bottom, and the settlement of the arch top. The purpose of monitoring the convergence of the tunnel, the settlement of the tunnel arch bottom, and the settlement of the arch top is to evaluate the deformation of the tunnel structure. Monitoring the deformation of the tunnel structure can help the staff to find problems in time and take corresponding measures to adjust and reinforce it to ensure the stability and safety of the tunnel; S5-23. The ground surface needs to be monitored twice a day and the tunnel needs to be monitored once a day. The frequency can be adjusted according to the settlement. During the monitoring process, the settlement of the ground surface points needs to be monitored twice a day to obtain more accurate data. The monitoring inside the tunnel needs to be monitored once a day. The monitoring frequency can be adjusted according to the actual settlement. If the settlement is large or a sudden change occurs, the monitoring frequency can be appropriately increased to timely grasp the deformation situation and take corresponding treatment measures to ensure the safety of construction and the stability of the tunnel structure.

[0023] The specific steps of lining construction in step S6 are: S6-1. Preparation work: Before lining construction, prepare the required materials, equipment and construction plan; S6-2, Formwork construction: According to the design requirements, install the steel bars required for lining in the formwork. The arrangement of the steel bars must meet the requirements of structural strength and stability; S6-3, Concrete pouring: Pour the concrete into the formwork, control the pouring speed and uniformity, and at the same time, ensure that the concrete fits the steel bars fully to prevent the formation of gaps and cracks; S6-4. Curing treatment: Curing treatment is carried out on the newly poured concrete to ensure its full hardening and strength development.

[0024] The purpose of the above steps is to ensure the accuracy, stability and quality of the lining structure to meet the engineering design requirements and ensure the safety and durability of the construction.

[0025] The method for the construction of the connection section in step S7 can be either cast-in-place concrete or assembled segments. Cast-in-place concrete refers to a method of pouring concrete on site at the connection section. This method requires building a formwork and installing the steel bars required for the connection section in the formwork. Then pour the concrete into the formwork and make the concrete fully dense by vibrating and other methods to ensure the strength and stability of the connection section. The advantage of cast-in-place concrete is that the construction process is highly controllable, and the shape and size of the connection section can be flexibly adjusted to meet different design requirements. Another method is to use assembled segments for the construction of the connection section. Assembled segments are prefabricated concrete segments that can be formed into connection sections by splicing and combining. This method requires the prefabricated segments to be transported to the connection section location and assembled together using appropriate connection methods. The advantage of assembled segments is that the construction speed is fast, which reduces the time and process of on-site construction, and also reduces the interference with the on-site environment. In addition, assembled segments also have higher quality control and can provide a more stable and consistent connection section structure. When choosing between cast-in-place concrete and assembled segments, multiple factors need to be considered, such as engineering design requirements, construction progress, material supply, etc. According to the specific situation, various factors can be comprehensively considered to select the most suitable connection section construction method to ensure the quality and construction efficiency of the connection section.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a subway shield tunnel in a water-rich soft stratum, characterized in that: The following steps are involved: S1. Preparatory work before construction: Before construction, conduct a detailed geological survey of the project to understand the distribution of strata and the status of groundwater, and formulate a detailed construction plan and emergency plan based on the survey results; S2. Site layout and equipment selection: Arrange temporary facilities in the construction area and select appropriate shield machines and auxiliary equipment according to geological conditions and construction requirements; S3. Soil reinforcement: Before construction, the soil of the connecting channel is reinforced, and the reinforcement depth is determined according to geological conditions and design requirements; S4. Shield machine positioning and commissioning: transport the shield machine to the construction site for installation and commissioning, and adjust various parameters of the shield machine according to geological conditions and construction requirements to ensure that it meets the construction needs; S5. Excavation of communication channel: Use a shield machine to excavate the communication channel; S6. Lining construction: After the excavation is completed, lining construction is carried out; S7, connection section construction: after the lining is completed, the connection section with the interval tunnel is constructed. The height and angle of the connection section are controlled and adjusted according to the design requirements; S8. Equipment dismantling and site cleaning: After the construction is completed, the shield machine and auxiliary equipment will be dismantled, and the construction site will be cleaned and restored.

2. The method for constructing a subway shield tunnel in a water-rich soft stratum according to claim 1 is characterized in that: The soil reinforcement method used in step S3 is any one of freezing method, high pressure grouting method, micro pile reinforcement, curtain method and pipe jacking method.

3. The method for constructing a subway shield tunnel in a water-rich soft stratum according to claim 1 is characterized in that: The temporary settings in step S2 include a construction platform, a material yard, and a mixing station.

4. The method for constructing a subway shield tunnel in a water-rich soft stratum according to claim 1 is characterized in that: The specific steps of communication channel mining in step S5 are: S5-1. Use a shield machine to excavate the communication channel, and control the advancement speed and excavation volume of the shield machine during the excavation process; S5-2. Closely monitor the deformation of the strata during the excavation process; S5-3. If the ground is deformed during the excavation process, timely measures must be taken to reinforce and treat it.

5. The method for constructing a subway shield tunnel section communication channel in a water-rich soft stratum according to claim 4 is characterized in that: The specific steps of monitoring in the step S5-2 are: S5-21, monitoring the settlement of the ground surface points on the left and right lines of the section tunnel and the settlement of the ground surface points on the profile; S5-22, monitoring of tunnel convergence, tunnel arch bottom settlement, and arch top settlement during pipe jacking; S5-23. It is necessary to inspect the surface twice a day and inside the tunnel once a day, and adjust the frequency according to the size of the settlement.

6. The method for constructing a subway shield tunnel section communication channel in a water-rich soft stratum according to claim 1, characterized in that: The specific steps of lining construction in step S6 are: S6-1. Preparation: Before lining construction, prepare the required materials, equipment and construction plan; S6-2, Formwork construction: According to the design requirements, install the steel bars required for lining in the formwork. The arrangement of the steel bars must meet the requirements of structural strength and stability; S6-3, Concrete pouring: Pour the concrete into the formwork, control the pouring speed and uniformity, and at the same time, ensure that the concrete and the steel bars fit well to prevent the formation of gaps and cracks; S6-4. Curing treatment: Curing treatment is carried out on the newly poured concrete to ensure its full hardening and strength development.

7. The method for constructing a subway shield tunnel in a water-rich soft stratum according to claim 1 is characterized in that: The lining in step S6 is reinforced concrete lining.

8. The method for constructing a subway shield tunnel section communication channel in a water-rich soft stratum according to claim 1, characterized in that: The method for constructing the connection section in step S7 may be either cast-in-place concrete or assembled segments.