Intermittent reverse construction method of pipe jacking working well based on traffic load feedback

Abstract

The application provides a pipe jacking working well intermittent reverse construction method based on traffic load feedback, establishes a pipe jacking working well segmented reverse construction system, a water stopping and drainage system and a traffic bearing system, divides a reverse construction unit along the depth direction of the working well and configures a stoppage stable state; target stoppage stable states and construction execution parameters are determined according to construction windows, working well construction states, underground water states and structure response data, and soil excavation and well wall reverse construction are implemented according to the construction execution parameters; the traffic bearing cover plate is closed and road traffic is restored after night construction is completed, working well structure responses and surrounding stratum responses caused by actual vehicle loads are obtained under the condition of maintaining working well drainage, and bearing response characteristics are formed; construction access results of the next construction window are determined according to the bearing response characteristics, and the construction execution parameters are updated, and the cycle construction is performed to the designed well bottom.

Description

Technical Field

[0001] This invention relates to the field of intermittent reverse construction of pipe jacking shafts, and in particular to a method for intermittent reverse construction of pipe jacking shafts based on traffic load feedback. Background Technology

[0002] With the continuous expansion of urban underground drainage networks, water supply networks, and other municipal underground pipelines, pipe jacking construction has been widely adopted due to its ability to reduce large-scale road excavation. Pipe jacking shafts, as crucial underground structures for launching and receiving pipe jacking equipment and connecting pipelines, typically require earthwork excavation, shaft wall support, water sealing and drainage, and bottom structure construction. For pipe jacking shafts located under existing urban roads, bridges, or in busy traffic areas, the construction area often cannot be closed for extended periods. Phased operations must be completed within a limited construction time, and road traffic must be restored during non-construction hours.

[0003] The corresponding project is located in the municipal road area, with some working wells under the overpass. The groundwater level is high, and the strata mainly consist of silty sand, silty clay and sandy gravel. During the construction period, only nighttime operations are allowed, and normal vehicle traffic is restored during the day, which makes it impossible to use the conventional continuous construction method under continuous closure conditions for the working wells.

[0004] Existing technology CN109306712A discloses a method for constructing a reverse-construction working shaft using pipe jacking. This method involves setting up a water-stop curtain and a ring beam, and constructing a reinforced concrete lining section by section as the working shaft is excavated downwards. The existing shaft wall structure is used to withstand lateral earth pressure, thus achieving the reverse-construction of the working shaft section by section. While this existing technology can solve the support problem during the excavation of deep foundation pits for working shafts, it mainly addresses the reverse-construction structure itself and the continuous section-by-section construction process. It does not address the control of the intermediate construction state of the working shaft under conditions of limited daily construction time and the need to repeatedly restore road traffic.

[0005] Existing technology CN114319433A discloses a prefabricated construction method for reverse-construction manholes. This method involves excavating the manhole layer by layer, sequentially installing prefabricated ring beam structures and manhole wall structures, repeating the excavation and wall installation until the designed depth is reached. Prefabricated components replace some of the on-site casting processes, thus forming the manhole structure. This existing technology mainly addresses the problems of cumbersome construction procedures and long construction cycles associated with traditional reverse-construction manholes. However, it still relies on layer-by-layer excavation and wall construction as the primary construction method. It does not establish a corresponding construction control closed loop to address the response of the manhole to the actual vehicle load during road opening periods when it is currently not in operation, or how this response can control the next construction stage.

[0006] The prior art CN1191258A discloses a spatiotemporal effect method for foundation pit excavation. Based on the foundation pit's spatial dimensions, excavation sequence, excavation time, and support structure, it implements layered, segmented, and time-limited excavation of the foundation pit, utilizing the unexcavated soil to provide phased support, thereby controlling foundation pit deformation. This prior art embodies the idea of ​​controlling foundation pit construction deformation using the spatiotemporal effect of soil. However, it primarily addresses the spatiotemporal relationship between soil and supports during general foundation pit excavation. It does not establish a stable shutdown state for the repeated intermittent working conditions of pipe jacking shafts operating at night and resuming road traffic during the day. Furthermore, it does not utilize the structural response of the working shaft and the response of the surrounding strata caused by actual vehicle loads after road reopening to determine the construction access status for the next construction window.

[0007] Therefore, although the existing reverse construction method for pipe jacking working shafts can achieve downward construction of the working shaft through measures such as segmented excavation, shaft wall support, water sealing and drainage, under the strict constraints of construction time and the need for periodic road traffic restoration, there may still be a problem that construction must be stopped before the current reverse construction unit has formed a stable support state. At the same time, after the road is restored, the structural and stratum response generated by the actual vehicle load and groundwater is usually only used as safety monitoring data. There is a lack of technical means to reverse the construction status and construction parameters of the next construction window based on the actual response. It is difficult to take into account the stability of the working shaft, the control of deformation of the surrounding strata, and the requirements for normal road traffic during intermittent construction. Summary of the Invention

[0008] The main objective of this invention is to provide an intermittent reverse construction method for pipe jacking shafts based on traffic load feedback, which solves the problems that when pipe jacking shafts can only be constructed intermittently on busy municipal roads, the support status is difficult to control stably during the downtime and the actual vehicle load response after the road is restored cannot be used for subsequent construction control.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an intermittent reverse construction method for pipe jacking working shaft based on traffic load feedback, comprising the following steps: S1. Establish a segmented reverse construction system, a water-stopping and drainage system, and a traffic-bearing system for the pipe jacking working shaft. Divide the reverse construction units along the depth direction of the working shaft and configure the road restoration-allowed shutdown stability state for the reverse construction units. S2. Obtain the current construction window, working well construction status, groundwater status and structural response data, and determine the target shutdown stability state and construction execution parameters of the current reverse construction unit based on the obtained data; S3. Perform soil excavation and well wall reverse construction of the current reverse construction unit according to the construction execution parameters, so that the working well can be converted to the target shutdown and stable state before the road is restored. S4. Close the traffic load cover at the manhole opening and restore road traffic. While maintaining drainage in the manhole, obtain the structural response of the manhole and the response of the surrounding strata during the actual vehicle load. S5. Determine the bearing response characteristics of the current shutdown stable state based on the structural response of the working well and the response of the surrounding strata. Generate the construction access results and construction execution parameters for the next construction window based on the bearing response characteristics, and control the construction of the next reverse construction unit according to the generated construction execution parameters. S6. Repeat steps S2 to S5 until the working well reaches the designed bottom, and complete the construction of the bottom structure of the working well and the back support structure of the pipe jacking.

[0010] In the preferred scheme, the shutdown stability state includes at least the soil support stability state and the well wall closure stability state; The soil support stability state is achieved by forming a pre-excavation area in the reverse construction unit and retaining the adjacent wall retention area of ​​the well wall to be constructed, so that the adjacent wall retention area and the well wall formed by the previous reverse construction unit jointly support the current excavation area. The well wall closure stability state is achieved by completing the transformation of the adjacent wall retention area into the well wall structure, so that the current reverse construction unit forms a closed well wall that is continuously connected to the previous reverse construction unit; Before the road is reopened to traffic, the current reverse construction unit should be kept in a stable state of soil support or well wall closure to avoid a work stoppage where a large area of ​​adjacent soil is removed while the well wall is not yet closed.

[0011] In the preferred scheme, step S2 involves constructing a construction window calculation process based on steady-state reachability; The current construction location, the status of the reverse construction unit, the stratum status, the groundwater status, and the status transition records of historical reverse construction units are used to form construction status data. The predicted completion time corresponding to the current reverse construction unit transitioning to different work stoppage stable states is recursively determined by using the historical status transition records adjacent to the current construction location. The effective construction time for the current construction window is obtained by subtracting the road restoration time corresponding to equipment removal, wellhead restoration, and traffic-bearing cover closure from the permitted nighttime construction time. The shutdown stability state that the current reverse construction unit can achieve is determined based on the relationship between the effective construction time and the predicted completion time, and the shutdown stability state that can be formed and maintained within the effective construction time is taken as the target shutdown stability state. As the reverse construction unit moves downwards, the predicted completion time of subsequent reverse construction units is updated based on the newly generated state transition records.

[0012] In the preferred scheme, when the soil support stability state transitions to the well wall closure stability state, the adjacent wall retention area is divided into multiple soil transition zones along the circumference of the working well; The soil conversion zones are constructed sequentially in a non-continuous and adjacent order. After the excavation of a soil conversion zone, a partial well wall construction structure is formed that is connected to the well wall of the previous reverse construction unit. Then, the construction of the next soil conversion zone that is not adjacent to the first soil conversion zone is carried out. The unconverted soil conversion zone is used to maintain the phased support of the adjacent soil, and as each soil conversion zone is converted in sequence, a continuous well wall construction structure is formed along the circumference of the working well. After completing the transformation of each soil conversion zone, the well wall of the current reverse construction unit is formed, so that the current reverse construction unit is transformed from a soil-supported stable state to a well wall closed stable state.

[0013] In the preferred scheme, in steps S4 and S5, traffic load events are identified based on changes in vehicle load during the road traffic opening period, and the monitoring data corresponding to the traffic load events are decomposed into a baseline response segment before the load is applied, a loading response segment formed by the vehicle load, and a recovery response segment after the vehicle leaves. The baseline response segment is used to determine the structural baseline state of the current traffic opening cycle. The loading response segment is used to determine the response amplitude of the traffic load-bearing cover plate, manhole wall and surrounding strata under actual vehicle load. The recovery response segment is used to determine the residual response and response recovery characteristics after the vehicle load is removed. The load-bearing response characteristics are formed based on the response amplitude, residual response, and response recovery characteristics corresponding to the same traffic load event, and the influence of long-term settlement of the working well and slow changes in groundwater on vehicle load response identification is eliminated by utilizing the baseline state changes between adjacent traffic load events. The obtained load-bearing response characteristics will be used as data input for construction control in the next construction window.

[0014] In the preferred scheme, in step S5, the load response characteristics are divided into load response amplitude information and unloading recovery information, and combined with groundwater changes to form a construction state characterization quantity. The working well response is determined to be in a stable recovery state, a limited recovery state, or an unstable recovery state based on the changes in the construction status characterization quantity during the continuous traffic opening cycle. Maintain or increase the construction progress of the next reverse construction unit while maintaining a stable recovery state; Under the restricted recovery state, reduce the construction advance and adjacent soil conversion range of the next reverse construction unit, so that the current reverse construction unit can preferentially form a stable soil support state. In the unstable recovery state, stop the downward excavation of the next reverse construction unit, carry out soil reinforcement, well wall support or drainage enhancement construction according to the abnormal response location, and re-determine the construction access result after the traffic load response is obtained again. The construction depth, adjacent wall retention range, and soil conversion sequence of the next reverse construction unit are generated from the construction access results, and the generated construction execution parameters are used to control the actual reverse construction.

[0015] In the preferred scheme, under unstable recovery conditions, the spatial distribution of structural response and formation response is determined based on monitoring locations set along the circumference of the working well and around the perimeter of the working well; Calculate the response change relationship between adjacent monitoring locations, determine the response concentration area and response change direction, and combine the groundwater changes to determine that the abnormal response corresponds to at least one of the abnormal types among well wall deformation, surrounding soil deformation, or groundwater seepage. For areas with concentrated abnormal responses due to well wall deformation, local support or reinforcement of the well wall perimeter is used; for areas with concentrated abnormal responses due to deformation of the surrounding soil, grouting reinforcement is used; and for areas with concentrated abnormal responses due to groundwater seepage, water-stopping reinforcement and drainage capacity adjustment are used. After completing the corresponding construction treatment, the bearing response characteristics under traffic load are reacquired, and the reacquired bearing response characteristics are used for subsequent construction access judgment.

[0016] In the preferred embodiment, a high-pressure jet grouting water-stopping reinforcement structure is installed around the working well and in the area affected by the pipe jacking tunnel. A water collection section and drainage pipe are installed inside the working well. The drainage pipe is connected to the ground drainage equipment through the reserved position of the traffic load-bearing cover plate, so that the working well is kept drained during the period when the road is open to traffic. Structural response monitoring locations were set up on the traffic load-bearing cover plate, the existing manhole wall, and the road surrounding the working manhole, and groundwater monitoring locations were also set up. Each monitoring location collects monitoring data according to a unified time benchmark, so that the traffic load data generated when vehicles pass through the working well area can establish a time correspondence with the traffic load cover response, well wall response, surrounding stratum response and groundwater response. Based on the time correspondence, multi-source response data under the same traffic load event is extracted and sent to the construction control computer.

[0017] In the preferred scheme, a construction response update model is established between the reverse construction parameters and the traffic load response; The completed reverse construction units are used to establish adjacent construction samples according to their construction depth. Each construction sample is associated with the corresponding reverse construction parameters, the stable state during work stoppage, and the load-bearing response characteristics obtained during the road traffic opening period. The local influence relationship of construction parameters on the response of the working well is determined based on the changes in reverse construction parameters and bearing response characteristics between adjacent construction samples, and a parameter response relationship updated with construction depth is formed. After completing a new reverse construction unit, the new construction sample is added to the parameter response relationship, and the influence of historical construction samples that are far from the current construction depth on the current parameter response relationship is reduced. Based on the updated parameter response relationship, predict the bearing response of the working well corresponding to different candidate construction parameters. Among the candidate construction parameters that meet the current construction access conditions, determine the construction depth, adjacent wall retention range and soil conversion sequence of the next reverse construction unit, and feed the determination results back to steps S2 and S3.

[0018] In the preferred embodiment, edge data acquisition nodes and construction control computers are set up at the construction site; Edge data acquisition nodes collect on-site monitoring data corresponding to traffic load-bearing cover plates, working well walls, surrounding strata and groundwater, and send the on-site monitoring data and construction status data to the construction control computer via RabbitMQ; The construction control computer is configured with a construction window processing module, a load response processing module, a construction access processing module, and a construction parameter update module. Each module is deployed using Docker containers and orchestrated using Kubernetes. The construction window processing module determines the target work stoppage stability state based on the construction status data, the load response processing module generates load response characteristics based on the on-site monitoring data, the construction access processing module generates construction access results based on the load response characteristics, and the construction parameter update module generates construction execution parameters based on the construction access results and historical reverse construction data. A PostgreSQL database is used to store the correlation data between the working well construction units, the stable state during shutdown, the on-site monitoring time sequence, the load response characteristics, the construction access results, and the construction parameter versions, so that the actual construction status, traffic load response, and subsequent construction execution parameters of each reverse construction unit form a traceable data correspondence.

[0019] This invention provides an intermittent reverse construction method for pipe jacking working shafts based on traffic load feedback. By dividing the pipe jacking working shaft into multiple reverse construction units along the depth direction and setting a shutdown stability state for each reverse construction unit that can be formed before the road is restored, the working shaft can maintain a certain soil support or shaft wall support state when the night construction ends, reducing the risk of soil instability and shaft wall deformation caused by intermittent construction.

[0020] The target shutdown stability state and construction execution parameters are determined based on the construction window, the construction status of the working well, the groundwater status, and the structural response. This ensures that the reverse construction progress matches the actual on-site construction time and the stability conditions of the working well, avoiding the situation where the support structure cannot be formed in time before the road is restored due to continuous excavation according to a fixed construction advance.

[0021] During the road traffic restoration period, the working manhole is kept dry and drained. The structural response of the working manhole and the response of the surrounding strata are obtained by using the traffic load generated by actual vehicles passing through the working manhole area. The actual on-site load generated by road traffic is transformed into the in-situ verification conditions of the working manhole construction state. Then, based on the bearing response characteristics, the construction access results and construction execution parameters of the next construction window are generated, thus forming a closed-loop construction process in which construction, traffic loading, state detection and subsequent construction adjustment are interconnected.

[0022] It can also continuously update subsequent reverse construction parameters based on construction parameters and traffic load response at different depths of the working shaft, and implement targeted support, grouting, water-stopping or drainage adjustments when abnormal structural response, stratum deformation or groundwater changes occur, so that the reverse construction process of the working shaft can adapt to changes in stratum conditions and construction status, and improve the stability and adaptability of intermittent construction of pipe jacking working shafts in complex municipal road environments. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart illustrating the overall process of the intermittent reverse construction method for pipe jacking working shafts based on traffic load feedback, as described in this invention.

[0024] Figure 2 This is a flowchart illustrating the process of achieving a stable shutdown state in this invention.

[0025] Figure 3 This is a flowchart for calculating the construction window and determining the target shutdown stability state of the present invention.

[0026] Figure 4 This is a flowchart illustrating the transition from the soil-supported stable state to the well-wall closed stable state according to the present invention.

[0027] Figure 5 This is a flowchart of the traffic load event response analysis of the present invention.

[0028] Figure 6 This is a flowchart of the construction access judgment and construction parameter update process of the present invention. Detailed Implementation

[0029] Example 1 like Figure 1 As shown, a method for intermittent reverse construction of a pipe jacking shaft based on traffic load feedback includes the following steps: S1. Establish a segmented reverse construction system, a water-stopping and drainage system, and a traffic-bearing system for the pipe jacking working shaft. Divide the reverse construction units along the depth direction of the working shaft and configure the road restoration-allowed shutdown stability state for the reverse construction units. S2. Obtain the current construction window, working well construction status, groundwater status and structural response data, and determine the target shutdown stability state and construction execution parameters of the current reverse construction unit based on the obtained data; S3. Perform soil excavation and well wall reverse construction of the current reverse construction unit according to the construction execution parameters, so that the working well can be converted to the target shutdown and stable state before the road is restored. S4. Close the traffic load cover at the manhole opening and restore road traffic. While maintaining drainage in the manhole, obtain the structural response of the manhole and the response of the surrounding strata during the actual vehicle load. S5. Determine the bearing response characteristics of the current stable state of shutdown based on the structural response of the working well and the response of the surrounding strata. Generate the construction access results and construction execution parameters for the next construction window based on the bearing response characteristics, and control the construction of the next reverse construction unit according to the generated construction execution parameters. S6. Repeat steps S2 to S5 until the working well reaches the designed bottom, and complete the construction of the bottom structure of the working well and the back support structure of the pipe jacking.

[0030] In the preferred scheme, the shutdown stability state includes at least the soil support stability state and the well wall closure stability state; The soil support stability is achieved by forming a pre-excavation area in the reverse construction unit and retaining the adjacent wall retention area of ​​the well wall to be constructed, so that the adjacent wall retention area and the well wall formed by the previous reverse construction unit jointly support the current excavation area. The well wall closure stability state is achieved by completing the transformation of the adjacent wall retention area into the well wall structure, so that the current reverse construction unit forms a closed well wall that is continuously connected to the previous reverse construction unit; Before the road is reopened to traffic, the current reverse construction unit should be kept in a stable state of soil support or well wall closure to avoid a work stoppage where a large area of ​​adjacent soil is removed while the well wall is not yet closed.

[0031] In the preferred scheme, step S2 involves constructing a construction window calculation process based on steady-state reachability; The current construction location, the status of the reverse construction unit, the stratum status, the groundwater status, and the status transition records of historical reverse construction units are used to form construction status data. The predicted completion time corresponding to the current reverse construction unit transitioning to different work stoppage stable states is recursively determined by using the historical status transition records adjacent to the current construction location. The effective construction time for the current construction window is obtained by subtracting the road restoration time corresponding to equipment removal, wellhead restoration, and traffic-bearing cover closure from the permitted nighttime construction time. The shutdown stability state that the current reverse construction unit can achieve is determined based on the relationship between the effective construction time and the predicted completion time, and the shutdown stability state that can be formed and maintained within the effective construction time is taken as the target shutdown stability state. As the reverse construction unit moves downwards, the predicted completion time of subsequent reverse construction units is updated based on the newly generated state transition records.

[0032] In the preferred scheme, when the soil support stability state transitions to the well wall closure stability state, the adjacent wall retention area is divided into multiple soil transition zones along the circumference of the working well; The soil conversion zones are constructed sequentially in a non-continuous and adjacent order. After the excavation of a soil conversion zone, a partial well wall construction structure is formed that is connected to the well wall of the previous reverse construction unit. Then, the construction of the next soil conversion zone that is not adjacent to the first soil conversion zone is carried out. The unconverted soil conversion zone is used to maintain the phased support of the adjacent soil, and as each soil conversion zone is converted in sequence, a continuous well wall construction structure is formed along the circumference of the working well. After completing the transformation of each soil conversion zone, the well wall of the current reverse construction unit is formed, so that the current reverse construction unit is transformed from a soil-supported stable state to a well wall closed stable state.

[0033] In the preferred scheme, in steps S4 and S5, traffic load events are identified based on changes in vehicle load during the road traffic opening period, and the monitoring data corresponding to the traffic load events are decomposed into a baseline response segment before the load is applied, a loading response segment formed by the vehicle load, and a recovery response segment after the vehicle leaves. The baseline response segment is used to determine the structural baseline state of the current traffic opening cycle. The loading response segment is used to determine the response amplitude of the traffic load-bearing cover plate, manhole wall and surrounding strata under actual vehicle load. The recovery response segment is used to determine the residual response and response recovery characteristics after the vehicle load is removed. The load-bearing response characteristics are formed based on the response amplitude, residual response, and response recovery characteristics corresponding to the same traffic load event, and the influence of long-term settlement of the working well and slow changes in groundwater on vehicle load response identification is eliminated by utilizing the baseline state changes between adjacent traffic load events. The obtained load-bearing response characteristics will be used as data input for construction control in the next construction window.

[0034] In the preferred scheme, in step S5, the load response characteristics are divided into load response amplitude information and unloading recovery information, and combined with groundwater changes to form a construction state characterization quantity. The working well response is determined to be in a stable recovery state, a limited recovery state, or an unstable recovery state based on the changes in the construction status characterization quantity during the continuous traffic opening cycle. Maintain or increase the construction progress of the next reverse construction unit while maintaining a stable recovery state; Under the restricted recovery state, reduce the construction advance and adjacent soil conversion range of the next reverse construction unit, so that the current reverse construction unit can preferentially form a soil support stability state. In the unstable recovery state, stop the downward excavation of the next reverse construction unit, carry out soil reinforcement, well wall support or drainage enhancement construction according to the abnormal response location, and re-determine the construction access result after the traffic load response is obtained again. The construction depth, adjacent wall retention range, and soil conversion sequence of the next reverse construction unit are generated from the construction access results, and the generated construction execution parameters are used to control the actual reverse construction.

[0035] In the preferred scheme, under unstable recovery conditions, the spatial distribution of structural response and formation response is determined based on monitoring locations set along the circumference of the working well and around the perimeter of the working well; Calculate the response change relationship between adjacent monitoring locations, determine the response concentration area and response change direction, and combine the groundwater changes to determine that the abnormal response corresponds to at least one of the abnormal types among well wall deformation, surrounding soil deformation, or groundwater seepage. For areas with concentrated abnormal responses due to well wall deformation, local support or reinforcement of the well wall perimeter is used; for areas with concentrated abnormal responses due to deformation of the surrounding soil, grouting reinforcement is used; and for areas with concentrated abnormal responses due to groundwater seepage, water-stopping reinforcement and drainage capacity adjustment are used. After completing the corresponding construction treatment, the bearing response characteristics under traffic load are reacquired, and the reacquired bearing response characteristics are used for subsequent construction access judgment.

[0036] In the preferred embodiment, a high-pressure jet grouting water-stopping reinforcement structure is installed around the working well and in the area affected by the pipe jacking tunnel. A water collection section and drainage pipe are installed inside the working well. The drainage pipe is connected to the ground drainage equipment through the reserved position of the traffic load-bearing cover plate, so that the working well is kept drained during the period when the road is open to traffic. Structural response monitoring locations were set up at the traffic load-bearing cover plate, the existing manhole wall, and the road surrounding the working manhole, and groundwater monitoring locations were also set up. Each monitoring location collects monitoring data according to a unified time benchmark, so that the traffic load data generated when vehicles pass through the working well area can establish a time correspondence with the traffic load cover response, well wall response, surrounding stratum response and groundwater response. Based on the time correspondence, multi-source response data under the same traffic load event is extracted and sent to the construction control computer.

[0037] In the preferred scheme, a construction response update model is established between the reverse construction parameters and the traffic load response; The completed reverse construction units are used to establish adjacent construction samples according to their construction depth. Each construction sample is associated with the corresponding reverse construction parameters, the stable state during work stoppage, and the load-bearing response characteristics obtained during the road traffic opening period. The local influence relationship of construction parameters on the response of the working well is determined based on the changes in reverse construction parameters and bearing response characteristics between adjacent construction samples, and a parameter response relationship updated with construction depth is formed. After completing a new reverse construction unit, the new construction sample is added to the parameter response relationship, and the influence of historical construction samples that are far from the current construction depth on the current parameter response relationship is reduced. Based on the updated parameter response relationship, predict the bearing response of the working well corresponding to different candidate construction parameters. Among the candidate construction parameters that meet the current construction access conditions, determine the construction depth, adjacent wall retention range and soil conversion sequence of the next reverse construction unit, and feed the determination results back to steps S2 and S3.

[0038] In the preferred embodiment, edge data acquisition nodes and construction control computers are set up at the construction site; Edge data acquisition nodes collect on-site monitoring data corresponding to traffic load-bearing cover plates, working well walls, surrounding strata and groundwater, and send the on-site monitoring data and construction status data to the construction control computer via RabbitMQ; The construction control computer is configured with a construction window processing module, a load response processing module, a construction access processing module, and a construction parameter update module. Each module is deployed using Docker containers and orchestrated using Kubernetes. The construction window processing module determines the target work stoppage stability state based on the construction status data, the load response processing module generates load response characteristics based on the on-site monitoring data, the construction access processing module generates construction access results based on the load response characteristics, and the construction parameter update module generates construction execution parameters based on the construction access results and historical reverse construction data. A PostgreSQL database is used to store the correlation data between the working well construction units, the stable state during shutdown, the on-site monitoring time sequence, the load response characteristics, the construction access results, and the construction parameter versions, so that the actual construction status, traffic load response, and subsequent construction execution parameters of each reverse construction unit form a traceable data correspondence.

[0039] Example 2 Further explanation in conjunction with Example 1, such as Figure 1The structure shown, the segmented reverse construction system, refers to a construction system that uses the wellhead ring beam and the completed upper well wall as the initial support structure, and proceeds segment by segment downwards along the depth direction of the working well for soil excavation, well wall construction, and the excavation of the next segment of soil. A reverse construction unit is a construction control section divided along the depth direction of the working well. After the completion of one reverse construction unit, a staged support structure capable of bearing the corresponding earth pressure and construction load is formed, before proceeding to the next reverse construction unit. In specific implementation, the height of the reverse construction unit can be determined according to the segmented reverse construction method of the working well. The standard construction segment uses a construction height of approximately 1.5m, and the well wall thickness is approximately 60cm. A portion of soil is retained near the well wall for manual treatment. These dimensions are specific engineering implementation parameters and can be adjusted according to the working well dimensions, geological conditions, and design documents.

[0040] The water-stopping and drainage system is used to control the seepage of groundwater from the perimeter of the working well into the well and to prevent water accumulation inside the well. It includes a water-stopping reinforcement structure around the working well, a water collection area inside the well, drainage pipes, and surface drainage equipment. The traffic-bearing system includes a traffic-bearing cover plate and its supporting foundation located at the well opening. After nighttime construction, the traffic-bearing cover plate is used to seal the well opening, allowing road traffic to resume, while simultaneously maintaining drainage inside the working well through pre-reserved drainage paths.

[0041] The construction status of the working well is used to characterize the degree of soil excavation, well wall formation, and stable state at the time of shutdown for the current reverse construction unit. Groundwater status is obtained from the groundwater levels inside and outside the working well and their changes over time. Structural response data is collected by monitoring equipment corresponding to the traffic-bearing cover, the working well wall, and the surrounding strata. Construction execution parameters are used to directly control subsequent soil excavation and reverse construction of the well wall, reflecting at least the construction depth, the extent of soil retention adjacent to the wall, and the soil conversion sequence. Therefore, the data obtained in step S2 is not construction management information, but rather engineering data directly reflecting the actual physical state of the working well, soil, groundwater, and support structure.

[0042] Step S3, based on the construction execution parameters obtained in Step S2, actually controls the soil excavation and well wall formation to achieve the target stable state after work stoppage. Step S4, after the traffic load-bearing cover is closed and road traffic is restored, uses the load generated by actual passing vehicles as the external force on site to obtain the actual physical response of the working well and the surrounding strata. Step S5, based on the actual physical response, determines whether the next reverse construction unit can continue construction and what construction parameters to use, thus forming a closed loop between on-site construction, actual traffic loading, structural response detection, and the control of the next stage of construction. Step S6, continues to repeat this closed loop until the working well reaches the designed well bottom, and then implements the bottom structure of the working well and the pipe jacking backing structure, so that the entire method ultimately acts on the actual working well physical structure, rather than stopping at the data analysis results.

[0043] The soil support stability state is a staged stability state formed before the current reverse construction unit has completed the construction of all the well walls. During construction, the soil is first excavated in the area away from the well wall to be constructed, forming the preliminary excavation zone, while the adjacent wall preservation zone is retained. The adjacent wall preservation zone continues to maintain the original soil continuity, so that it shares the lateral earth pressure and local construction disturbance at the current excavation depth with the well wall already formed in the previous reverse construction unit, avoiding the simultaneous exposure of the soil around the working well before the well wall is formed.

[0044] The working shaft is constructed by first mechanically excavating the main earthwork, then retaining the soil in the adjacent shaft wall area before manual excavation. Therefore, the retained area near the shaft wall provides a basis for actual engineering construction. The width of the retained area does not need to be exactly the same for each reverse construction unit; it can be determined based on the soil compaction, groundwater conditions, current excavation depth, the condition of the previous shaft wall section, and on-site deformation monitoring results. During construction, it should be ensured that the retained area near the shaft wall remains continuous or can form effective staged soil support during the period of soil support stability.

[0045] The well wall closure stability state is the structurally stable state formed after the soil conversion of the adjacent retaining area is completed. Soil conversion refers to the gradual removal of the adjacent retaining area and the completion of well wall reinforcement connections, formwork support, and concrete forming at the corresponding locations, so that the current reverse construction unit forms a well wall structure that is continuous along the circumference of the working well and connected to the previous reverse construction unit. Before the road is reopened to traffic, the current construction state must be in either a soil support stability state or a well wall closure stability state. The working well should not remain in an intermediate state where a large portion of the adjacent soil has been removed but the corresponding well wall has not yet formed continuous support. This structurally reduces the possibility of local soil deformation caused by the combined effects of daytime vehicle loads and groundwater.

[0046] The construction window calculation process based on steady-state reachability is used to determine which type of stop-work steady state can be formed within the current allowable construction time. The calculation process first reads the location and construction status of the current reverse construction unit, and then reads the stratum status and groundwater status at the corresponding construction depth. Next, it reads the actual time record of the transition from one construction state to another stop-work steady state for adjacent reverse construction units that have already been completed.

[0047] The state transition record corresponds at least to the location of the reverse construction unit, the start time of construction, the time when a stable stop state was formed, the type of stable stop state formed, the groundwater condition during construction, and the construction depth. In actual processing, the completed reverse construction unit closest to the current construction depth and with similar formation and groundwater conditions is used as the prediction reference for the current reverse construction unit. The actual state transition time of the most recently completed reverse construction unit is used as the initial prediction basis for the next reverse construction unit. When a new reverse construction unit is completed, the prediction basis for subsequent reverse construction units is updated with the newly generated actual state transition record, so that the prediction process is iteratively updated as the working well continues to descend.

[0048] The current construction window does not simply adopt the total time allowed for construction at night. Instead, it first reserves the road restoration time required for equipment removal, well cleaning, wellhead restoration, and closing of traffic-bearing covers from the allowed nighttime construction time. The remaining portion is used as the effective construction time for soil excavation and well wall reverse construction.

[0049] The construction control computer compares the effective construction time with the predicted completion time for achieving a stable soil support state and a stable well wall closure state. If the effective construction time only guarantees a stable soil support state, the excavation of the adjacent area is stopped, and the current reverse construction unit ends its nighttime construction while preserving the adjacent soil. If the effective construction time guarantees a stable well wall closure state, and allows time for wellhead restoration, the adjacent soil conversion and well wall forming continue. Therefore, the construction window calculation results ultimately determine whether soil excavation and well wall construction continue, constituting a technical process for controlling the actual construction process.

[0050] When transitioning from a supported, stable state to a closed, stable state, the entire adjacent retaining area is not removed at once. Instead, the adjacent retaining area is divided into multiple soil transition zones along the circumference of the working well. The number and circumferential length of the soil transition zones are determined based on the cross-sectional dimensions of the working well, the stability of the strata, and the available construction space. All soil transition zones together constitute the adjacent retaining area of ​​the current reverse construction unit.

[0051] During construction, a soil transfer zone is first excavated. After excavating to the connection point of the well wall of the previous reverse construction unit, the exposed area is trimmed, and the steel reinforcement of the well wall at the corresponding position of the current reverse construction unit and the previous reverse construction unit is connected. Subsequently, formwork and supports are set at this position to form a partial well wall construction structure. After completing the construction structure of this area, adjacent soil transfer zones are not directly and continuously excavated. Instead, the excavation is moved to a circumferentially discontinuous adjacent position for the construction of the next soil transfer zone.

[0052] The construction is carried out cyclically in the manner described above, with the already excavated areas supported by the local well wall construction structure, while the unexcavated areas continue to utilize the original or less disturbed adjacent soil for intermittent support. After each soil conversion zone is completed in sequence, a continuous reinforcement, formwork, and support system is formed along the circumference of the working well. Then, the well wall concrete construction of the current reverse construction unit is carried out, so that the current well wall and the well wall of the previous reverse construction unit form a continuous load-bearing structure.

[0053] Vertical steel reinforcement is connected at each excavation point, and construction in the adjacent area is controlled by excavating, connecting, and restoring the soil to a stable state as needed. This implementation method further clarifies this as a discontinuous circumferential transition method, allowing the soil itself and the artificially formed well wall structure to alternately bear local support during the transition process.

[0054] After traffic resumes, edge data acquisition nodes continuously collect the responses of the traffic load cover, manhole wall, and surrounding strata according to a unified time reference. A traffic load event is a continuous physical process in which a vehicle enters the influence range of the traffic load cover of the working manhole, generates a structural response, the vehicle leaves, and the structural response gradually recovers.

[0055] The baseline response segment is taken from continuous stable monitoring data prior to the significant application of vehicle load, used to determine the immediate baseline state of the working manhole before the onset of this traffic load event. Because the working manhole may experience long-term slow settlement and groundwater changes, the immediate baseline state before the load application is used for each traffic load event, rather than always using the fixed initial values ​​at the start of construction.

[0056] The loading response segment begins when the monitored response deviates continuously from the immediate baseline state, continues to increase, and reaches the peak response value of this event. The load response amplitude is obtained by measuring the change between the peak response value of this traffic load event and the immediate baseline state, and is used to reflect the transient load impact on the traffic load cover, manhole wall, and surrounding strata when a vehicle passes by.

[0057] The recovery response phase begins when the vehicle load decreases and the monitored response starts to recover from its peak value towards a stable state, and continues until the response enters a new steady state. The unrecovered portion between the new steady state and the immediate baseline state of this event is considered the residual response. The process of the peak response changing towards the new steady state characterizes the response recovery features. If the response can quickly return to near the immediate baseline state after the vehicle leaves, it indicates that the traffic load mainly produced a recoverable response. If the residual response persists or gradually accumulates after consecutive traffic load events, it indicates that the current shutdown steady state has a deformation trend that requires further control.

[0058] By comparing the baseline response segment, loading response segment, and recovery response segment within the same traffic load event, the interference of long-term slow settlement and slow changes in groundwater level on the judgment of short-term vehicle load response can be reduced, so that the bearing response characteristics mainly represent the impact of actual vehicle load on the current construction status of the working well.

[0059] The construction status characterization quantity is formed by the bearing response characteristics and groundwater changes. Its purpose is not to give an abstract score to the working well, but to determine whether the current physical state of the working well can withstand the construction disturbance caused by the continued excavation of the next reverse construction unit.

[0060] The stable recovery state is defined as a state in which the structural response remains within the engineering control range during traffic loads, the structural response recovers after the vehicle load decreases, the groundwater level remains normal, and no significant cumulative deformation trend appears during continuous traffic opening cycles. In this state, the next reverse construction unit can maintain the current construction parameters; when the on-site structural response remains stable and has sufficient control margin, the construction progress of the next reverse construction unit can also be increased within the design allowable range.

[0061] The restricted recovery state is a state in which the traffic load response is increased compared to the previous construction stage, or there is a certain residual response after the vehicles have left, but it has not yet reached the construction warning conditions and the response still has a convergence trend. In this state, the temporary support capacity of the soil support stability can be maintained by reducing the construction advance of the next reverse construction unit, increasing the degree of retention of adjacent soil, or reducing the range of one soil transfer.

[0062] The unsteady recovery state is characterized by structural response reaching the construction warning range, response failing to recover after vehicles leave, residual deformation accumulation due to continuous traffic load events, abnormal groundwater changes, or significant seepage and soil anomalies on site. In this state, excavation must cease, and construction should not be continued simply by changing data thresholds. Instead, actual soil reinforcement, well wall support, or drainage enhancement measures should be implemented. After these measures are completed, road traffic should be restored, and actual vehicle load responses should be collected again. Only after the bearing capacity response characteristics that meet the construction access conditions are regained can the next reverse construction unit proceed.

[0063] It is clear that when the monitoring data of the foundation pit reaches the warning value, the rate of change accelerates significantly, the ground load suddenly increases, and the surface settlement is abnormal, it is necessary to strengthen the observation and take measures. Therefore, the control boundaries of the stable recovery state, the limited recovery state, and the unstable recovery state can be determined by combining the design allowable value, the monitoring warning value, and the trend of change, rather than by the subjective judgment of the construction personnel.

[0064] Anomaly response spatial localization is achieved using monitoring points located at different positions along the perimeter of the working manhole and on the surrounding roads. The construction control computer first establishes a correspondence based on the actual spatial location of the monitoring points, and then compares the response amplitude, residual response, and recovery status of adjacent monitoring locations during the same traffic load event.

[0065] When the structural response at a certain monitoring location and its adjacent locations is significantly higher than that at other corresponding locations in the working well, and this difference persists during continuous traffic load events, this area is identified as a response concentration area. Based on the direction of change of the response concentration area from the working well wall to the surrounding strata, and combined with the groundwater status in this area, it can be further determined that the anomaly mainly originates from well wall deformation, surrounding soil deformation, or groundwater seepage.

[0066] Anomalies in well wall deformation are mainly manifested as concentrated structural responses at the corresponding well wall location, while the response of the surrounding surface is relatively weak. In this case, local support or reinforcement of the well wall perimeter should be implemented at the corresponding well wall location. Anomalies in the surrounding soil deformation are mainly manifested as the well wall and surrounding surface responses extending along the same spatial direction. In this case, grouting reinforcement should be implemented in the corresponding area to improve the integrity of the soil and limit further deformation. Anomalies in groundwater seepage are manifested as changes in structural response accompanied by abnormal groundwater conditions, increased water inflow within the well, or localized leakage. In this case, water-stopping reinforcement should be implemented along the abnormal seepage path, and drainage capacity should be adjusted.

[0067] After the construction is completed, the completion of the reinforcement project should not be used as the basis for resuming construction. Instead, the road traffic should be restored again by using traffic load-bearing covers to obtain the load-bearing response characteristics under actual vehicle loads. The retest results should then be re-input into the construction access judgment process, thus forming a complete technical closed loop between anomaly identification, physical reinforcement, actual load retesting, and resumption of construction.

[0068] The water-stopping structure of the working well can be formed by high-pressure jet grouting. High-pressure jet grouting piles are arranged around the perimeter of the working well and in the area affected by the jacking of the tunnel. The high-pressure cement grout cuts and mixes the original soil, and after solidification, a continuous or overlapping water-stopping reinforcement structure is formed.

[0069] The double-pipe high-pressure jet grouting process is adopted, and the layout range and reinforcement depth of the jet grouting piles are determined according to the stratum conditions. During the jet grouting process, the grouting pressure, grout mixing state, lifting speed and rotation state are controlled.

[0070] The working well is equipped with a water collection section to collect groundwater and construction water that seeps into the well and then pumps it to the ground through drainage pipes. After the traffic-bearing cover is closed, the drainage pipes remain connected to the ground drainage equipment through the reserved position on the cover, so the resumption of road traffic during the day will not cause the drainage of the working well to be interrupted.

[0071] During the construction of traffic load-bearing cover plates, it is necessary to ensure that the cover plates and hoisting system meet the actual construction load requirements. The crane lifting capacity for hoisting steel structure cover plates is checked using the following formula: ; In the formula, The crane's lifting capacity is expressed in tons. The weight of the traffic load-bearing cover plate component is in tons. Weight of slings and hooks, in tons; The dynamic load factor used in the hoisting process is 1.1.

[0072] The calculation relationship for the restricted construction area under the bridge is as follows: ; The calculation results are used to compare with the rated lifting capacity of the actual hoisting equipment at the corresponding boom length and operating radius to determine whether the traffic load cover opening and closing equipment has sufficient load-bearing capacity.

[0073] When four-point hoisting is used in the area under the bridge, the actual force calculation for a single sling is as follows: ; In the formula, 5.6 represents the tensile force borne by a single sling under the corresponding lifting condition, in kilonewtons; 9.8 represents the mass of the traffic load-bearing cover plate in this project, in tons; 1.1 represents the gravitational acceleration value used when converting mass to gravity; 4 represents the four lifting points. This refers to the included angle parameter of the slings under this lifting condition. By calculating the actual force on a single sling and comparing it with the allowable bearing capacity of the selected sling, it can be determined that the slings meet the construction requirements for repeated opening and closing of the traffic load-bearing cover.

[0074] The surveying and control of the working wells utilizes a total station and a level to establish a unified spatial benchmark. When verifying the coordinates of the control stakes and the traverse azimuth, the closure error control relationship is specified as follows: ; In the formula, This corresponds to the number of stations during the traverse survey process. This relationship is used to verify the closure accuracy of the control network for the construction of the working well, ensuring that the well wall displacement, road surface changes, and spatial position of the working well obtained at different construction stages have a unified measurement benchmark.

[0075] Structural response monitoring locations are set at the traffic load cover, the completed manhole wall, and the road surrounding the working manhole. Groundwater monitoring locations are used to obtain the groundwater status around the working manhole. Edge data acquisition nodes attach unified time information to each monitoring data point, enabling a one-to-one correspondence between the cover response, manhole wall response, surrounding stratum response, and groundwater status generated by the same vehicle passing over the traffic load cover, providing a data foundation for traffic load event identification as described in claim 5.

[0076] The construction response update model uses actual completed reverse construction units as construction samples, rather than using general training data unrelated to the current project. Each construction sample at least saves the construction depth, construction execution parameters, the shutdown stability state formed before road restoration, and the load-bearing response characteristics obtained during the subsequent road traffic reopening for that reverse construction unit.

[0077] The construction samples are arranged sequentially according to their construction depth. When updating parameters at the current construction depth, priority is given to selecting completed construction samples that are close to the current construction depth and have similar formation conditions. By comparing the direction of change of construction execution parameters and the direction of change of corresponding bearing response characteristics between adjacent construction samples, the local impact of changes in construction parameters on the actual response of the working well within the current working well and the current formation section is determined.

[0078] Once a new reverse construction unit is completed, the actual construction execution parameters used in that unit, the final stable state after shutdown, and the bearing response characteristics obtained under actual daytime vehicle loads are correlated to form a new construction sample, which is then added to the existing construction sample sequence according to the construction depth. For earlier construction samples that are far from the current construction depth and whose corresponding stratum conditions are significantly different, their role in the current parameter judgment is reduced, so that the parameter response relationship mainly reflects the actual engineering conditions near the current excavation depth.

[0079] Candidate construction parameters are generated based on the current construction access conditions, the design-allowed construction range, and the verified range of construction parameters. The construction response update model determines the potential load-bearing response change trend caused by different candidate construction parameters based on the parameter response relationships shown in construction samples near the current depth. Candidate parameters that meet the current construction access conditions and enable the next reverse construction unit to reach the target shutdown stability state are determined as the construction execution parameters for the next reverse construction unit.

[0080] Therefore, the output of the construction response update model is not an abstract prediction result, but a specific construction depth, adjacent wall retention range and soil conversion sequence for the next reverse construction unit. The output results are re-entered into steps S2 and S3 and used for on-site excavation and well wall reverse construction, so that the algorithm calculation results can be directly applied to the actual engineering object.

[0081] Edge data acquisition nodes are set up on the data acquisition side of the construction site and connected to traffic load-bearing cover plate monitoring equipment, working well wall monitoring equipment, surrounding strata monitoring equipment, and groundwater monitoring equipment. The edge data acquisition nodes standardize the acquisition time of different monitoring devices and combine the working well number, reverse construction unit, monitoring location, acquisition time, and monitoring value to form the on-site monitoring data.

[0082] RabbitMQ is used to transmit on-site monitoring data, construction status data, load response characteristics, construction access results, and construction execution parameters between different data processing services at the construction site. For continuously generated monitoring time-series data, the edge data acquisition node sends the data to the corresponding message channel after acquisition. The load response processing module reads the data to identify traffic load events and extract load response characteristics. The construction access processing module reads the load response characteristics and groundwater status to generate construction access results. The construction parameter update module then generates the construction execution parameters for the next reverse construction unit based on the construction access results and historical reverse construction data.

[0083] The construction window processing module, the load response processing module, the construction access processing module, and the construction parameter update module are each deployed using Docker containers, ensuring that each processing function has an independent operating environment. Kubernetes provides unified orchestration for these Docker containers, enabling the construction control computer to start the corresponding services according to the configuration after startup, and to restore the corresponding data processing service after a single service exits abnormally, thus preventing the entire on-site monitoring data processing from stopping due to the failure of one data processing function.

[0084] The PostgreSQL database is used to establish traceable data associations between different construction stages. The working shaft construction unit data records the construction depth and current construction status of each inverted construction unit; the shutdown stability state data records the actual stability state reached by each inverted construction unit before road restoration; the on-site monitoring time series data saves monitoring locations, monitoring times, and corresponding monitoring values; the load-bearing response characteristic data saves the baseline response, loading response, and recovery response processing results corresponding to different traffic load events; the construction access result data records whether continued excavation is allowed at each construction window and the corresponding restriction status; and the construction parameter version data saves the actual output construction depth, adjacent wall retention range, and soil conversion sequence after each parameter update.

[0085] All types of data are linked through working wells, reverse construction units, and time information, enabling the construction control computer to trace the actual construction parameters, the resulting stable state after shutdown, the actual traffic load response after road restoration, and the next stage construction parameters generated from that response from any reverse construction unit. The construction control computer ultimately sends the construction execution parameters to the on-site construction execution terminal to guide or control earthwork excavation equipment, manual excavation of adjacent walls, well wall construction, drainage equipment, and reinforcement construction. This ensures that the data processing process of the software modules is ultimately translated into actual construction actions of the working wells, rather than merely generating information for personnel to read.

[0086] Example 3 Further illustrating this with reference to Examples 1-2, this embodiment provides an intermittent reverse construction method for pipe jacking shafts based on traffic load feedback. This method is suitable for pipe jacking shaft construction located on existing urban roads where construction time is limited by traffic conditions and the road requires periodic restoration of traffic flow. Figures 1 to 6 This embodiment focuses on a pipe jacking shaft within a municipal road area. The groundwater level in the construction area is high, and the strata include silty sand, silty clay, and sandy soil. An intermittent construction method is adopted, with nighttime construction and daytime road traffic restoration. The corresponding groundwater level is approximately 1.10m to 3m, and the main strata include silty sand and silty clay, reflecting the high groundwater, soft, and sandy strata construction environment faced by this embodiment.

[0087] like Figure 1 As shown, the construction process begins with establishing a segmented reverse-construction system for the working shaft, a water-stopping and drainage system, and a traffic-bearing system. Before construction, surveying and setting out are conducted to determine the working shaft boundary, bottom design elevation, and jacking pipe axis based on the design location. High-pressure jet grouting water-stopping reinforcement structures are then constructed around the working shaft and in the area affected by the jacking pipe's entry and exit points. The high-pressure jet grouting piles utilize a double-pipe construction method, arranged around the working shaft, in the rear area, and in the jacking pipe's entry and exit points according to the actual geological conditions. Adjacent jet grouting piles are overlapped to form a water-stopping reinforcement area. The high-pressure jet grouting piles use a diameter of approximately 600mm, with a grouting pressure of 20MPa to 30MPa. Before construction, test piles are conducted based on the actual geological conditions, and construction parameters are adjusted.

[0088] The working well is equipped with a water collection section and drainage pipes. Groundwater and construction water are collected in the water collection section and then discharged by a water pump. The drainage pipes extend to the ground through the reserved position of the traffic load cover, so that drainage of the working well can continue even after the traffic load cover is closed and road traffic is restored.

[0089] The method combines in-well water collection and drainage, external water interception, and high-pressure jet grouting pile water-stopping curtain. Pumping facilities are also installed in the reserved positions of the well cover to ensure that pumping and drainage can continue during the period when construction work is stopped.

[0090] The working manhole is equipped with a traffic-bearing cover and corresponding supporting foundation. The traffic-bearing cover is made of steel structure, and its load-bearing capacity is designed according to the allowable vehicle load of the construction road. In this embodiment, the corresponding project uses a steel structure cover that meets the requirements for a 55t vehicle load, making it possible to open the manhole for construction at night and close it during the day to restore vehicle traffic. When the traffic-bearing cover is repeatedly opened and closed, the lifting safety performance is checked based on the weight of the cover, the weight of the slings, the rated lifting capacity of the lifting equipment, and the actual working radius.

[0091] The working shaft is divided into multiple reverse construction units along its depth. Based on engineering conditions, this embodiment can form a standard reverse construction unit with a construction height of approximately 1.5m and a shaft wall thickness of approximately 60cm. The specific construction height is adjusted according to the actual geological stability, groundwater conditions, construction window, and the structural design requirements of the working shaft; it is not required that all reverse construction units adopt the same construction height. The pipe jacking working shaft adopts segmented reverse construction, with each segment having an excavation depth of approximately 1.5m and a wall thickness of approximately 60cm, providing a concrete implementation basis for the segmented reverse construction in this embodiment.

[0092] like Figure 2 As shown, each reverse construction unit forms one of two stable states: a soil-supported stable state and a well-wall closed stable state. Upon entering a new reverse construction unit, the current construction area is divided into a preliminary excavation zone and a retaining zone adjacent to the well wall to be constructed. First, the soil in the preliminary excavation zone is excavated to create a construction space in the center of the working well. Simultaneously, the retaining zone is preserved, allowing the unexcavated adjacent soil to form a staged support together with the well wall already completed in the previous reverse construction unit.

[0093] In this embodiment, the upper earthwork can be carried out using a backhoe excavator, while the lower earthwork can be carried out using a combination of a mini backhoe excavator and manual labor. The area adjacent to the well wall is not completely excavated mechanically at once; instead, a certain range of adjacent soil is preserved.

[0094] Mechanical excavation of the main area was adopted, and about 0.30m of soil was left near the well wall before manual excavation, thereby avoiding mechanical over-excavation and improving the control accuracy of the working well structure dimensions.

[0095] When the nighttime construction window is insufficient to complete the conversion of the adjacent retaining area and the formation of the current reverse construction unit's manhole wall, the adjacent retaining area will not be removed on a large scale. Instead, construction will cease once the current construction unit has achieved a stable state of soil support. At this point, the interior of the working manhole will be cleaned, construction equipment will be removed or moved to a safe location, the drainage system will be restored, and the traffic-bearing cover will be closed. This ensures that the working manhole remains stable during daytime road opening periods, supported by the manhole wall of the previous reverse construction unit and the adjacent retaining area.

[0096] When the construction window meets the requirements for well wall construction, the soil support stability state is converted into a well wall closed stability state. For example... Figure 4 As shown, the adjacent retaining area is divided into multiple soil conversion zones along the circumference of the working well. One of the soil conversion zones is excavated first. After the excavation of this area is completed, the exposed positions are trimmed, and the reinforcing bars of the current reverse construction unit are connected to the corresponding reinforcing bars of the previous reverse construction unit. Subsequently, the corresponding formwork and formwork supports are installed.

[0097] After completing the construction of one soil conversion zone, priority is given to selecting the next soil conversion zone that is not discontinuously adjacent to the current soil conversion zone to continue construction, so that the unexcavated adjacent soil continues to retain its phased support function. For the construction of the well wall reinforcement, the corresponding vertical reinforcement is installed and connected after each excavation, and the construction of the adjacent area is controlled by excavating, connecting, and promptly restoring the stability of the construction area. Therefore, it can provide an engineering basis for the above-mentioned soil conversion method.

[0098] Repeat the above process until the construction of each soil transfer zone is completed and a continuous well wall reinforcement and formwork support structure is formed along the circumference of the working well. Then, pour the concrete for the well wall of the current reverse construction unit, continuously connecting the current well wall with the well wall of the previous reverse construction unit, forming a closed and stable well wall. After the well wall concrete construction is completed and reaches the strength requirements for the next stage of construction, proceed to the next reverse construction unit.

[0099] like Figure 3 As shown, after each nighttime construction window begins, the construction control computer performs a construction window calculation based on steady-state reachability. First, it obtains the nighttime construction time allowed by the road management conditions for the day, and then reserves the time required for equipment removal, manhole cleaning, closing of traffic load-bearing covers, and road restoration. This determines the effective construction time that can actually be used for the excavation and manhole wall construction of the current reverse construction unit.

[0100] The construction control computer reads the current construction depth, the current status of the reverse construction unit, the soil condition, and the groundwater condition, and retrieves historical state transition records from adjacent completed reverse construction units. These historical state transition records include the corresponding construction depth, start time, time required to reach soil support stability, time required to reach wellbore closure stability, and the soil and groundwater conditions during the corresponding construction period.

[0101] Historical construction records with similar construction depths, geological conditions, and groundwater conditions to the current reverse construction unit are selected as the basis for prediction. Based on this, the predicted completion time required for the current reverse construction unit to achieve both soil support stability and well wall closure stability is determined.

[0102] When the effective construction time is sufficient to allow the current reverse construction unit to form a closed and stable well wall and complete the wellhead restoration, the closed and stable well wall state is taken as the target stable state for work stoppage; when the effective construction time is insufficient to form a closed and stable well wall state, but sufficient to meet the requirements for construction in the excavated area and safe restoration of the construction site, the stable state of soil support is taken as the target stable state for work stoppage; when the effective construction time is insufficient to safely reach the above-mentioned stable state, the scope of the current construction is reduced, and construction areas that may not be able to complete the stable transition before the road is restored are not entered.

[0103] Therefore, the calculation output of the construction window is directly used to determine the actual soil excavation range and well wall construction range for that night, rather than simply a construction schedule plan.

[0104] like Figure 5 As shown, after the nighttime construction is completed and the target work stoppage and stabilization state is achieved, personnel and construction equipment inside the well will be evacuated to a safe location. The drainage system of the working well will remain operational, the traffic load-bearing cover will be closed, and road traffic will be restored. Corresponding monitoring equipment will be installed at the traffic load-bearing cover, the completed well wall, the road surrounding the working well, and the groundwater monitoring location. All monitoring equipment will collect data using a unified time reference.

[0105] After the road is opened, edge data acquisition nodes continuously collect data on the traffic load cover response, manhole wall response, surrounding strata response, and groundwater status. When a vehicle enters the working manhole's influence area and acts on the traffic load cover, the monitoring data changes relative to the steady state before the vehicle's entry, thus identifying a traffic load event.

[0106] For a traffic load event, the stable monitoring section before the vehicle's significant impact is defined as the baseline response section, the stage where the structural response changes from the baseline state and reaches the peak response after the vehicle enters is defined as the loading response section, and the stage where the structural response recovers from the peak to the stable state after the vehicle leaves is defined as the recovery response section.

[0107] The response amplitude corresponding to this traffic load event is determined based on the baseline response segment and the loaded response segment. The residual response and structural response recovery state after the vehicle leaves are determined based on the recovery response segment, thus forming the load-bearing response characteristics of the corresponding traffic load event. By continuously collecting multiple traffic load events, it can be determined whether the current stable state at the work stoppage will produce continuous cumulative deformation under the repeated loading of actual road vehicles.

[0108] The load-bearing response characteristics and groundwater conditions are used together to determine the construction state. When the groundwater condition remains normal, the structural and stratum responses under traffic loads are within the allowable control range, and the response can recover after the vehicles leave, the current construction state is determined as a stable recovery state, allowing the next reverse construction unit to continue construction according to the current construction parameters.

[0109] When the traffic load response increases or there is a residual response after the vehicle leaves, but the overall situation remains stable or convergent, the current construction state is defined as a restricted recovery state. In the next construction window, the construction advance is reduced, and the degree of wall preservation is increased or the primary soil transfer range is reduced, so that subsequent reverse construction prioritizes maintaining strong soil support.

[0110] When the monitoring response reaches the early warning control range, continuous vehicle load events result in significant residual deformation accumulation, or abnormal changes occur in the groundwater condition, the current construction state is determined to be an unstable recovery state, and the next reverse construction unit is stopped from continuing downward excavation. It is stipulated that when the foundation pit monitoring data reaches the early warning value, the rate of change accelerates, the ground load suddenly increases, or abnormal settlement occurs on the surrounding surface, monitoring needs to be strengthened and corresponding measures taken.

[0111] For unstable recovery states, the location of concentrated abnormal responses is determined based on monitoring points arranged along the perimeter of the working well and the surrounding roads. If the abnormality is mainly concentrated in the well wall area, local support or reinforcement of the well wall perimeter is implemented; if the abnormality extends to the surrounding strata, grouting reinforcement is implemented on the corresponding soil; if the abnormality is accompanied by changes in groundwater level, increased water inflow in the well, or local seepage, water-stopping reinforcement is implemented in the corresponding area and the drainage capacity of the working well is adjusted.

[0112] After reinforcement is completed, instead of immediately resuming excavation for the next reverse construction unit, the traffic load-bearing cover is closed again and road traffic is restored. The load-bearing response characteristics under actual vehicle loads are then re-collected. Only after the re-measurement results meet the construction access conditions can the next construction window be entered.

[0113] like Figure 6 As shown, this embodiment sets up edge data acquisition nodes and a construction control computer at the construction site. The edge data acquisition nodes are connected to traffic load-bearing cover plate monitoring equipment, working well wall monitoring equipment, surrounding strata monitoring equipment, and groundwater monitoring equipment, respectively, and add working well construction unit information, monitoring location, and acquisition time to the acquired data.

[0114] On-site monitoring data is sent to the construction control computer via RabbitMQ. The construction control computer is equipped with a construction window processing module, a load response processing module, a construction access processing module, and a construction parameter update module. Each module is deployed using Docker containers and orchestrated using Kubernetes.

[0115] Construction window processing module execution Figure 3 The corresponding target shutdown stability state determination process; execution by the load response processing module. Figure 5The corresponding traffic load event identification and bearing response feature extraction process; the construction access processing module determines the stable recovery state, restricted recovery state, or unstable recovery state based on the bearing response features and groundwater status; the construction parameter update module determines the construction depth, adjacent wall retention range, and soil conversion sequence of the next reverse construction unit based on the construction access results.

[0116] The PostgreSQL database stores the correlation data between construction units of the working shaft, the stable state after shutdown, the on-site monitoring time series, load response characteristics, construction access results, and construction parameter versions. Each data point establishes a correspondence with the construction unit and time information, thereby enabling the tracking of the construction parameters used for each reverse construction unit, the resulting stable state after shutdown, and the actual traffic load response obtained after the road was opened during the day.

[0117] As the working shaft continues to descend, the completed reverse construction units are used as construction samples. The construction execution parameters, shutdown stability, and bearing response characteristics of the corresponding reverse construction units are correlated, and the local relationship between construction parameters and bearing response is updated based on construction samples with adjacent construction depths and similar formation conditions.

[0118] When entering a new reverse construction unit, the construction parameter update module prioritizes using historical construction samples that are close to the current construction depth. Based on the verified actual construction results, it determines the appropriate construction advance, wall retention range, and soil conversion sequence under the current construction conditions, so that subsequent construction parameters are continuously updated as the working well construction depth, stratum condition, groundwater condition, and actual traffic load response change.

[0119] according to Figure 1 The cycle executes the following steps: construction window judgment, reverse construction, formation of a stable stop state, closure of the traffic load cover, road restoration, acquisition of actual vehicle load response, construction access judgment, and updating of construction parameters. When the working shaft has not yet reached the designed shaft bottom, the reverse construction cycle re-enters according to the next construction window. Once the working shaft reaches the designed shaft bottom, downward segmented excavation stops, the foundation is inspected and treated, the subbase and reinforced concrete base slab are constructed, and the post-jacking structure is constructed after the pipe jacking starting shaft.

[0120] Through the above construction process, the working shaft of the pipe jacking project is kept in a stable state of soil support or a stable state of closed shaft wall before the end of each day's construction and the restoration of road traffic. The structural response of the working shaft and the response of the surrounding strata generated by the actual vehicle load during the road restoration period are used to control the construction access status and construction execution parameters of the next construction window. This makes the intermittent reverse construction at night, the road traffic load during the day, the monitoring of the working shaft structure, and the subsequent reverse construction a continuous closed loop.

[0121] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for intermittent reverse construction of a pipe jacking shaft based on traffic load feedback, characterized by: Includes the following steps: S1. Establish a segmented reverse construction system, a water-stopping and drainage system, and a traffic-bearing system for the pipe jacking working shaft. Divide the reverse construction units along the depth direction of the working shaft and configure the road restoration-allowed shutdown stability state for the reverse construction units. S2. Obtain the current construction window, working well construction status, groundwater status and structural response data, and determine the target shutdown stability state and construction execution parameters of the current reverse construction unit based on the obtained data; S3. Perform soil excavation and well wall reverse construction of the current reverse construction unit according to the construction execution parameters, so that the working well can be converted to the target shutdown and stable state before the road is restored. S4. Close the traffic load cover at the manhole opening and restore road traffic. While maintaining drainage in the manhole, obtain the structural response of the manhole and the response of the surrounding strata during the actual vehicle load. S5. Determine the bearing response characteristics of the current stable state of shutdown based on the structural response of the working well and the response of the surrounding strata. Generate the construction access results and construction execution parameters for the next construction window based on the bearing response characteristics, and control the construction of the next reverse construction unit according to the generated construction execution parameters. S6. Repeat steps S2 to S5 until the working well reaches the designed bottom, and complete the construction of the bottom structure of the working well and the back support structure of the pipe jacking.

2. The intermittent reverse construction method for pipe jacking shafts based on traffic load feedback as described in claim 1, characterized in that: The stable state during shutdown includes at least the stable state of soil support and the stable state of well wall closure; The soil support stability state is achieved by forming a pre-excavation area in the reverse construction unit and retaining the adjacent wall retention area of ​​the well wall to be constructed, so that the adjacent wall retention area and the well wall formed by the previous reverse construction unit jointly support the current excavation area. The well wall closure stability state is achieved by completing the transformation of the adjacent wall retention area into the well wall structure, so that the current reverse construction unit forms a closed well wall that is continuously connected to the previous reverse construction unit; Before the road is reopened to traffic, the current reverse construction unit should be kept in a stable state of soil support or well wall closure to avoid a work stoppage where a large area of ​​adjacent soil is removed while the well wall is not yet closed.

3. The intermittent reverse construction method for pipe jacking shafts based on traffic load feedback as described in claim 1, characterized in that: In step S2, a construction window calculation process based on steady-state reachability is constructed; The current construction location, the status of the reverse construction unit, the stratum status, the groundwater status, and the status transition records of historical reverse construction units are used to form construction status data. The predicted completion time corresponding to the current reverse construction unit transitioning to different work stoppage stable states is recursively determined by using the historical status transition records adjacent to the current construction location. The effective construction time for the current construction window is obtained by subtracting the road restoration time corresponding to equipment removal, wellhead restoration, and traffic-bearing cover closure from the permitted nighttime construction time. The shutdown stability state that the current reverse construction unit can achieve is determined based on the relationship between the effective construction time and the predicted completion time, and the shutdown stability state that can be formed and maintained within the effective construction time is taken as the target shutdown stability state. As the reverse construction unit moves downwards, the predicted completion time of subsequent reverse construction units is updated based on the newly generated state transition records.

4. The intermittent reverse construction method for pipe jacking shaft based on traffic load feedback as described in claim 2, characterized in that: When the soil supports the stable state and the well wall closes the stable state, the adjacent wall retention area is divided into multiple soil transition zones along the circumference of the working well. The soil conversion zones are constructed sequentially in a non-continuous and adjacent order. After the excavation of a soil conversion zone, a partial well wall construction structure is formed that is connected to the well wall of the previous reverse construction unit. Then, the construction of the next soil conversion zone that is not adjacent to the first soil conversion zone is carried out. The unconverted soil conversion zone is used to maintain the phased support of the adjacent soil, and as each soil conversion zone is converted in sequence, a continuous well wall construction structure is formed along the circumference of the working well. After completing the transformation of each soil conversion zone, the well wall of the current reverse construction unit is formed, so that the current reverse construction unit is transformed from a soil-supported stable state to a well wall closed stable state.

5. The intermittent reverse construction method for pipe jacking shaft based on traffic load feedback according to claim 1, characterized in that: In steps S4 and S5, traffic load events are identified based on changes in vehicle load during the road traffic opening period. The monitoring data corresponding to the traffic load events are decomposed into the baseline response segment before the load is applied, the loading response segment formed by the vehicle load, and the recovery response segment after the vehicle leaves. The baseline response segment is used to determine the structural baseline state of the current traffic opening cycle. The loading response segment is used to determine the response amplitude of the traffic load-bearing cover plate, manhole wall and surrounding strata under actual vehicle load. The recovery response segment is used to determine the residual response and response recovery characteristics after the vehicle load is removed. The load-bearing response characteristics are formed based on the response amplitude, residual response, and response recovery characteristics corresponding to the same traffic load event, and the influence of long-term settlement of the working well and slow changes in groundwater on vehicle load response identification is eliminated by utilizing the baseline state changes between adjacent traffic load events. The obtained load-bearing response characteristics will be used as data input for construction control in the next construction window.

6. The intermittent reverse construction method for pipe jacking shaft based on traffic load feedback according to claim 5, characterized in that: In step S5, the load response characteristics are divided into load response amplitude information and unloading recovery information, and combined with groundwater changes to form a construction state characterization quantity; The working well response is determined to be in a stable recovery state, a limited recovery state, or an unstable recovery state based on the changes in the construction status characterization quantity during the continuous traffic opening cycle. Maintain or increase the construction progress of the next reverse construction unit while maintaining a stable recovery state; Under the restricted recovery state, reduce the construction advance and adjacent soil conversion range of the next reverse construction unit, so that the current reverse construction unit can preferentially form a soil support stability state. In the unstable recovery state, stop the downward excavation of the next reverse construction unit, carry out soil reinforcement, well wall support or drainage enhancement construction according to the abnormal response location, and re-determine the construction access result after the traffic load response is obtained again. The construction depth, adjacent wall retention range, and soil conversion sequence of the next reverse construction unit are generated from the construction access results, and the generated construction execution parameters are used to control the actual reverse construction.

7. The intermittent reverse construction method for pipe jacking working shaft based on traffic load feedback according to claim 6, characterized in that: in Under unstable recovery conditions, the spatial distribution of structural and formation responses is determined based on monitoring locations set along the circumference of the working well and around the perimeter of the working well. Calculate the response change relationship between adjacent monitoring locations, determine the response concentration area and response change direction, and combine the groundwater changes to determine that the abnormal response corresponds to at least one of the abnormal types among well wall deformation, surrounding soil deformation, or groundwater seepage. For areas with concentrated abnormal responses due to well wall deformation, local support or reinforcement of the well wall perimeter is used; for areas with concentrated abnormal responses due to deformation of the surrounding soil, grouting reinforcement is used; and for areas with concentrated abnormal responses due to groundwater seepage, water-stopping reinforcement and drainage capacity adjustment are used. After completing the corresponding construction treatment, the bearing response characteristics under traffic load are reacquired, and the reacquired bearing response characteristics are used for subsequent construction access judgment.

8. The intermittent reverse construction method for pipe jacking working shaft based on traffic load feedback according to claim 1, characterized in that: A high-pressure jet grouting water-stopping reinforcement structure is installed around the working well and in the area affected by the pipe jacking tunnel. A water collection section and drainage pipe are installed inside the working well. The drainage pipe is connected to the ground drainage equipment through the reserved position of the traffic load cover plate so that the working well is kept drained during the period when the road is open to traffic. Structural response monitoring locations were set up at the traffic load-bearing cover plate, the existing manhole wall, and the road surrounding the working manhole, and groundwater monitoring locations were also set up. Each monitoring location collects monitoring data according to a unified time benchmark, so that the traffic load data generated when vehicles pass through the working well area can establish a time correspondence with the traffic load cover response, well wall response, surrounding stratum response and groundwater response. Based on the time correspondence, multi-source response data under the same traffic load event is extracted and sent to the construction control computer.

9. The intermittent reverse construction method for pipe jacking shaft based on traffic load feedback according to claim 6, characterized in that: Establish a construction response update model between reverse construction parameters and traffic load response; The completed reverse construction units are used to establish adjacent construction samples according to their construction depth. Each construction sample is associated with the corresponding reverse construction parameters, the stable state during work stoppage, and the load-bearing response characteristics obtained during the road traffic opening period. The local influence relationship of construction parameters on the response of the working well is determined based on the changes in reverse construction parameters and bearing response characteristics between adjacent construction samples, and a parameter response relationship updated with construction depth is formed. After completing a new reverse construction unit, the new construction sample is added to the parameter response relationship, and the influence of historical construction samples that are far from the current construction depth on the current parameter response relationship is reduced. Based on the updated parameter response relationship, predict the bearing response of the working well corresponding to different candidate construction parameters. Among the candidate construction parameters that meet the current construction access conditions, determine the construction depth, adjacent wall retention range and soil conversion sequence of the next reverse construction unit, and feed the determination results back to steps S2 and S3.

10. The intermittent reverse construction method for pipe jacking shaft based on traffic load feedback according to claim 1, characterized in that: Edge data acquisition nodes and construction control computers are set up at the construction site; Edge data acquisition nodes collect on-site monitoring data corresponding to traffic load-bearing cover plates, working well walls, surrounding strata and groundwater, and send the on-site monitoring data and construction status data to the construction control computer via RabbitMQ; The construction control computer is configured with a construction window processing module, a load response processing module, a construction access processing module, and a construction parameter update module. Each module is deployed using Docker containers and orchestrated using Kubernetes. The construction window processing module determines the target work stoppage stability state based on the construction status data, the load response processing module generates load response characteristics based on the on-site monitoring data, the construction access processing module generates construction access results based on the load response characteristics, and the construction parameter update module generates construction execution parameters based on the construction access results and historical reverse construction data. A PostgreSQL database is used to store the correlation data between the working well construction units, the stable state during shutdown, the on-site monitoring time sequence, the load response characteristics, the construction access results, and the construction parameter versions, so that the actual construction status, traffic load response, and subsequent construction execution parameters of each reverse construction unit form a traceable data correspondence.

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