Construction method for constructing deep foundation pit by using existing structure

Abstract

The invention discloses a construction method for constructing a deep foundation pit by using an existing structure, and relates to the technical field of foundation pit construction.The construction method comprises the steps that the existing enclosure structure is positioned, a crown beam of the existing enclosure structure is chiseled away after excavation, and a fender post design scheme is confirmed; small-diameter secant piles are constructed according to the fender post design scheme, and a newly-built fender post is formed; the joint of the newly-built enclosure structure and the existing enclosure structure is reinforced; the crown beam is constructed, and the newly-built enclosure structure and the existing enclosure structure are connected; according to the excavation process, the defect position of the enclosure structure is reinforced; establishing and training a correlation model based on the water level data and the deformation data to obtain a water level deformation correlation model; and according to the real-time water level change, performing defect prediction and early warning on the enclosure structure in combination with the water level deformation correlation model, and reinforcing the defects of the enclosure structure. According to the method, the occupied area of the enclosure structure is reduced, the existing enclosure piles are repaired, and the defects of the enclosure structure can be accurately found and reinforced.

Description

Technical Field

[0001] This invention relates to the field of foundation pit construction technology, and more specifically, to a construction method for deep foundation pit construction using existing structures. Background Technology

[0002] The deep foundation pit retaining system is a key structure to ensure the safety of foundation pit excavation. Its construction method and structural form need to be comprehensively selected based on factors such as geological conditions, surrounding environment, and excavation depth. Conventional retaining structures include pile retaining structures, diaphragm walls, construction piles, and soil nailing walls. In terms of construction methods, all of these involve excavating deep soil, pouring concrete or other materials to form a retaining structure. In the construction of small foundation pits, steel sheet piles are sometimes driven directly into the soil. In some cases, there are also reverse construction and semi-reverse construction methods, where underground structural beams and slabs are constructed first as supports, and the structure is excavated and constructed layer by layer from top to bottom to reduce the amount of internal support required.

[0003] Existing technologies often require the excavation of deep soil, which is time-consuming, labor-intensive, and extremely costly. Existing technologies also result in large land area occupied by the retaining structure and low land utilization. Furthermore, existing technologies cannot promptly obtain data on water level and deformation within the foundation pit to take effective measures and ensure the safety of the foundation pit.

[0004] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0005] In view of the problems in related technologies, this invention proposes a construction method for deep foundation pit construction using existing structures, so as to overcome the above-mentioned technical problems existing in the existing related technologies.

[0006] Therefore, the specific technical solution adopted by the present invention is as follows:

[0007] A construction method for deep foundation pit construction utilizing existing structures, comprising the following steps:

[0008] Locate the existing retaining structure, excavate and remove the existing retaining structure cap beam, and confirm the retaining pile design scheme.

[0009] Construct small-diameter interlocking piles according to the retaining pile design scheme to form a new retaining structure;

[0010] Reinforce the connection between the new and existing enclosure structures;

[0011] Construction of the capping beam connects the newly built retaining structure and the existing retaining structure;

[0012] According to the excavation process, the foundation pit is excavated layer by layer, and the defective parts of the retaining structure are reinforced.

[0013] A correlation model is established and trained based on water level data and deformation data to obtain a water level deformation correlation model. Based on real-time water level changes and combined with the water level deformation correlation model, defects in the retaining structure are predicted and warned, and the defects in the retaining structure are reinforced.

[0014] Furthermore, the existing retaining structure is located, and after excavation, the existing retaining structure capping beam is removed. The design scheme for the retaining piles is then confirmed, including the following steps:

[0015] Based on the construction data of nearby buildings, locate the position of the existing retaining structure of the foundation pit;

[0016] Excavate the soil above the existing retaining structure until it is exposed to the ground, and remove the existing retaining structure cap beam.

[0017] The design scheme for retaining piles is determined based on the actual location of the existing retaining structure.

[0018] Furthermore, reinforcement of the connection between the new and existing enclosure structures includes:

[0019] The gaps between the new and existing retaining structures are filled by using all-round high-pressure jet grouting piles, thus reinforcing the connection between the new and old retaining structures.

[0020] Further, the construction of the capping beam, connecting the newly built retaining structure and the existing retaining structure, includes the following steps:

[0021] Excavation of the earthwork above the capping beam;

[0022] The construction includes the capping beam and the first concrete support, and the existing and new retaining structures are connected through the capping beam.

[0023] The connected structure, combined with concrete supports, forms the first layer of support.

[0024] Furthermore, reinforcement methods include:

[0025] At the junction of the old and new retaining structures and at the defective locations of the existing foundation pit retaining structure, the structures are reinforced by chiseling and spraying concrete. When seepage occurs, polyurethane and filter media are used to treat and reinforce the seepage points.

[0026] Furthermore, a correlation model is established and trained based on water level data and deformation data to obtain a water level-deformation correlation model. Based on real-time water level changes and in conjunction with the water level-deformation correlation model, defect prediction and early warning are performed on the retaining structure. Reinforcement of the retaining structure to address defects includes the following steps:

[0027] Historical water level data and historical deformation data of the retaining structure are acquired and preprocessed. Based on the preprocessed historical water level data and historical deformation data of the retaining structure, an associated dataset is constructed.

[0028] Construct a correlation model and train the correlation model based on the correlation dataset to obtain a water level deformation correlation model;

[0029] By using a water level deformation correlation model and based on real-time water level changes, defects in the retaining structure are predicted and early warnings are given, and corresponding strategies are derived.

[0030] Based on the response strategy, the defects in the building envelope are reinforced.

[0031] Furthermore, constructing a correlation model and training the correlation model based on the correlation dataset to obtain the water level deformation correlation model includes the following steps:

[0032] The associated dataset is divided into a training set and a validation set;

[0033] Initialize the association model and train it using the training set and cross-entropy loss function;

[0034] Based on the coefficient of determination and the validation set, the prediction accuracy of the trained correlation model is evaluated, and the trained correlation model is optimized according to the evaluation results to obtain the water level deformation correlation model.

[0035] Furthermore, by utilizing a water level deformation correlation model and based on real-time water level changes, defects in the retaining structure are predicted and early warnings are issued, resulting in response strategies including the following steps:

[0036] Acquire real-time water level data and real-time deformation data, and perform preprocessing;

[0037] By using a water level deformation correlation model, the preprocessed real-time water level data is analyzed to obtain the defect prediction results of the retaining structure.

[0038] Based on the design parameters of the foundation pit and the actual construction situation, different levels of early warning thresholds are set;

[0039] Based on the defect prediction results of the building envelope and the set early warning threshold, a response strategy is generated.

[0040] The beneficial effects of this invention are as follows:

[0041] 1. This invention uses small-diameter interlocking piles, existing retaining structures, and construction piles to form a new closed retaining structure, which reduces the land area occupied by the retaining structure and the workload of the retaining project.

[0042] 2. Repair existing retaining piles using materials such as shotcrete, filter media, and polyurethane to make them meet construction requirements.

[0043] 3. By using the water level deformation correlation model to predict and warn of defects in the retaining structure, the defects in the retaining structure can be accurately located and reinforced. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart of a construction method for deep foundation pit construction using existing structures, according to an embodiment of the present invention. Detailed Implementation

[0046] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0047] According to an embodiment of the present invention, a construction method for deep foundation pit construction using existing structures is provided.

[0048] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figure 1 As shown, according to an embodiment of the present invention, a construction method for deep foundation pit construction using existing structures includes the following steps:

[0049] S1. Locate the existing retaining structure, excavate and remove the existing retaining structure cap beam, and confirm the retaining pile design scheme, thereby constructing small-diameter interlocking piles according to the retaining pile design scheme.

[0050] Specifically, the process of locating the existing retaining structure, excavating and removing the existing retaining structure's capping beam, and confirming the retaining pile design scheme includes the following steps:

[0051] Based on the construction data of nearby buildings, locate the position of the existing retaining structure of the foundation pit;

[0052] Excavate the soil above the existing retaining structure until it is exposed to the ground, and remove the existing retaining structure cap beam.

[0053] The design scheme for retaining piles is determined based on the actual location of the existing retaining structure.

[0054] It needs to be explained that, based on the construction data of the adjacent buildings, the location of the retaining structure of the base was determined, and the upper earthwork was excavated until it was exposed to the ground. The existing capping beam of the retaining structure was removed, and the design scheme of the retaining piles was adjusted according to the actual location of the retaining structure.

[0055] S2. Construct small-diameter interlocking piles according to the retaining pile design scheme to form a new retaining structure, thereby determining the new retaining structure to be used in conjunction with the existing retaining structure.

[0056] It should be explained that the interlocking pile construction process using full casing interlocking piles is used to construct the interlocking piles, forming a complete retaining structure.

[0057] S3. Reinforce the connection between the new and existing enclosure structures to complete the connection between the new and old enclosure structures and form a closed water-stopping system.

[0058] Specifically, reinforcement of the connection between the new and existing building envelope includes:

[0059] The gaps between the new and existing retaining structures are filled by using all-round high-pressure jet grouting piles, thus reinforcing the connection between the new and old retaining structures.

[0060] It should be explained that after the interlocking piles are completed, the gap between them and the existing interlocking piles will be filled using MJS method piles (all-round high-pressure jetting method piles) to complete the connection between the new and old retaining structures and form a closed water-stopping system.

[0061] S4. Construct the cap beam to connect the new enclosure structure and the existing enclosure structure, thereby connecting the new enclosure structure and the existing enclosure structure together, and forming the first support with concrete supports.

[0062] Specifically, the construction of the capping beam, connecting the new enclosure structure and the existing enclosure structure, includes the following steps:

[0063] Excavation of the earthwork above the capping beam;

[0064] The construction includes the capping beam and the first concrete support, and the existing and new retaining structures are connected through the capping beam.

[0065] The connected structure, combined with concrete supports, forms the first layer of support.

[0066] It should be explained that after the construction of the retaining structure is completed, the earthwork above the cap beam is excavated, and then the cap beam and the first layer of concrete support are constructed. The existing retaining piles and the newly built retaining piles are connected by the cap beam, and the first layer of support is formed by combining the concrete support.

[0067] S5. According to the excavation process, the foundation pit is excavated layer by layer, and the defective locations of the retaining structure are reinforced. The existing retaining piles are repaired using materials such as shotcrete, filter material, and polyurethane to meet the construction requirements.

[0068] Specifically, the reinforcement methods include:

[0069] At the junction of the old and new retaining structures and at the defective locations of the existing foundation pit retaining structure, the structures are reinforced by chiseling and spraying concrete. When seepage occurs, polyurethane and filter media are used to treat and reinforce the seepage points.

[0070] It should be explained that, according to the excavation process, the foundation pit is excavated layer by layer. At the junction of the new and old retaining structures and at the defective locations of the existing foundation pit retaining structures, the soil is reinforced by chiseling and spraying concrete. When the seepage is severe, polyurethane and filter materials are used to divert the seepage points.

[0071] During reinforcement, excess concrete on the outside of the pile joint is removed. A specialist is assigned to use a pneumatic hammer to remove the surface concrete at the pile joint until the concrete surface is reached. Loose cement slurry and stones on the surface are cleaned up. The leaking area is cut and grooved. A hole is drilled at the leaking point in the trench and a plastic pipe is inserted to divert the leaking water to a nearby dewatering well. After the water flow decreases after a period of diversion, the diversion pipe is sealed with water-soluble polyurethane using a pile joint sealing device.

[0072] S6. Establish and train a correlation model based on water level data and deformation data to obtain a water level deformation correlation model; predict and warn of defects in the retaining structure based on real-time water level changes and in combination with the water level deformation correlation model, and reinforce the retaining structure to address the defects. Thus, by using the water level deformation correlation model to predict and warn of defects in the retaining structure, the defects in the retaining structure can be accurately identified and reinforced.

[0073] Specifically, a correlation model is established and trained based on water level data and deformation data to obtain a water level-deformation correlation model; based on real-time water level changes and in conjunction with the water level-deformation correlation model, defect prediction and early warning of the retaining structure are performed, and the defects of the retaining structure are reinforced, including the following steps:

[0074] Historical water level data and historical deformation data of the retaining structure are acquired and preprocessed. Based on the preprocessed historical water level data and historical deformation data of the retaining structure, an associated dataset is constructed.

[0075] Construct a correlation model and train the correlation model based on the correlation dataset to obtain a water level deformation correlation model;

[0076] By using a water level deformation correlation model and based on real-time water level changes, defects in the retaining structure are predicted and early warnings are given, and corresponding strategies are derived.

[0077] Based on the response strategy, the defects in the building envelope are reinforced.

[0078] Specifically, constructing a correlation model and training it based on the correlation dataset to obtain a water level deformation correlation model includes the following steps:

[0079] The associated dataset is divided into a training set and a validation set;

[0080] Initialize the association model and train it using the training set and cross-entropy loss function;

[0081] Based on the coefficient of determination and the validation set, the prediction accuracy of the trained correlation model is evaluated, and the trained correlation model is optimized according to the evaluation results to obtain the water level deformation correlation model.

[0082] Specifically, by using a water level deformation correlation model and based on real-time water level changes, defects in the retaining structure are predicted and early warnings are issued, resulting in response strategies including the following steps:

[0083] Acquire real-time water level data and real-time deformation data, and perform preprocessing;

[0084] By using a water level deformation correlation model, the preprocessed real-time water level data is analyzed to obtain the defect prediction results of the retaining structure.

[0085] Based on the design parameters of the foundation pit and the actual construction situation, different levels of early warning thresholds are set;

[0086] Based on the defect prediction results of the building envelope and the set early warning threshold, a response strategy is generated.

[0087] It should be explained that historical water level data, including real-time water level values, rate of change, and fluctuation amplitude, is obtained from the cloud-based precipitation water level monitor. Historical deformation data of the retaining structure, including displacement, settlement, and tilt information, is obtained from the deep foundation pit deformation intelligent monitor.

[0088] Historical water level data and historical deformation data of the retaining structure were preprocessed, including data cleaning, data synchronization, data standardization, and normalization. The preprocessed dataset was then divided into a training set and a validation set, with 70% of the data used as the training set and 30% used as the validation set.

[0089] Choose a suitable statistical or machine learning model to establish the correlation between water level data and deformation data, such as a neural network model as the correlation model. Initialize the weights and biases of the correlation model, input the training set data into the model, calculate the model's output, and train and optimize the correlation model based on the cross-entropy loss function.

[0090] The trained model was validated using validation set data to evaluate its predictive performance. The coefficient of determination was selected as the evaluation criterion, and the model was further optimized based on the validation results to obtain the water level deformation correlation model.

[0091] Real-time water level data and real-time deformation data are acquired and preprocessed. The preprocessed real-time water level data and deformation data are then input into the water level-deformation correlation model. The water level-deformation correlation model predicts the location of possible defects in the retaining structure based on the real-time data.

[0092] Based on the design parameters of the foundation pit and the actual construction conditions, different levels of early warning thresholds are set. For example, the early warning can be divided into three levels:

[0093] Level 1 warning (low risk): When the deformation or leakage at the predicted defect location is minor, a Level 1 warning is issued.

[0094] Level 2 warning (medium risk): A level 2 warning is issued when the deformation or leakage at the predicted defect location is severe.

[0095] Level 3 warning (high risk): A Level 3 warning is issued when the deformation or leakage at the predicted defect location is very severe.

[0096] Based on the prediction results of the water level deformation correlation model and the set warning threshold, a corresponding warning signal is generated. For example:

[0097] When the predicted deformation exceeds the first-level warning threshold but does not reach the second-level warning threshold, a first-level warning signal is generated.

[0098] A level 2 warning signal is generated when the predicted deformation exceeds the level 2 warning threshold but does not reach the level 3 warning threshold.

[0099] When the predicted deformation exceeds the level 3 warning threshold, a level 3 warning signal is generated.

[0100] Based on the defect locations and early warning signals predicted by the model, on-site construction personnel conducted a detailed inspection of the retaining structure to confirm the existence of defects and carried out corresponding reinforcement operations. The on-site inspection results were fed back into the water level deformation correlation model to verify the predictive accuracy and early warning effectiveness of the model.

[0101] To facilitate understanding of the above technical solutions of the present invention, the working principle or operation method of the present invention in actual process will be described in detail below.

[0102] In summary, by utilizing the above-mentioned technical solution of this invention, a new closed retaining structure is formed by employing small-diameter interlocking piles, existing retaining structures, and method piles, thereby reducing the footprint of the retaining structure and the workload of the retaining project. Existing retaining piles are repaired using shotcrete, filter media, polyurethane, and other materials to meet construction requirements. By using a water level deformation correlation model to predict and warn of defects in the retaining structure, defects can be accurately located and reinforced.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for deep foundation pit construction using existing structures, characterized in that, The method includes the following steps: Locate the existing retaining structure, excavate and remove the existing retaining structure cap beam, and confirm the retaining pile design scheme. Construct small-diameter interlocking piles according to the retaining pile design scheme to form a new retaining structure; Reinforce the connection between the new and existing enclosure structures; Construction of the capping beam connects the newly built retaining structure and the existing retaining structure; According to the excavation process, the foundation pit is excavated layer by layer, and the defective parts of the retaining structure are reinforced. A correlation model is established and trained based on water level data and deformation data to obtain a water level deformation correlation model. Based on real-time water level changes and combined with the water level deformation correlation model, defects in the retaining structure are predicted and warned, and the defects in the retaining structure are reinforced.

2. The construction method for deep foundation pit construction using existing structures according to claim 1, characterized in that, The process of locating the existing retaining structure, excavating and removing the existing retaining structure's capping beam, and confirming the retaining pile design includes the following steps: Based on the construction data of nearby buildings, locate the position of the existing retaining structure of the foundation pit; Excavate the soil above the existing retaining structure until it is exposed to the ground, and remove the existing retaining structure cap beam. The design scheme for retaining piles is determined based on the actual location of the existing retaining structure.

3. The construction method for deep foundation pit construction using existing structures according to claim 1, characterized in that, The reinforcement of the connection between the newly built enclosure structure and the existing enclosure structure includes: The gaps between the new and existing retaining structures are filled by using all-round high-pressure jet grouting piles, thus reinforcing the connection between the new and old retaining structures.

4. The construction method for deep foundation pit construction using existing structures according to claim 1, characterized in that, The construction of the cap beam, connecting the newly built retaining structure and the existing retaining structure, includes the following steps: Excavation of the earthwork above the capping beam; The construction includes the capping beam and the first concrete support, and the existing and new retaining structures are connected through the capping beam. The connected structure, combined with concrete supports, forms the first layer of support.

5. A construction method for deep foundation pit construction using existing structures according to claim 1, characterized in that, The reinforcement methods include: At the junction of the old and new retaining structures and at the defective locations of the existing foundation pit retaining structure, the structures are reinforced by chiseling and spraying concrete. When seepage occurs, polyurethane and filter media are used to treat and reinforce the seepage points.

6. A construction method for deep foundation pit construction using existing structures according to claim 1, characterized in that, The process of establishing and training a correlation model based on water level data and deformation data to obtain a water level-deformation correlation model; predicting and warning of defects in the retaining structure based on real-time water level changes and in conjunction with the water level-deformation correlation model; and reinforcing the defects in the retaining structure includes the following steps: Historical water level data and historical deformation data of the retaining structure are acquired and preprocessed. Based on the preprocessed historical water level data and historical deformation data of the retaining structure, an associated dataset is constructed. Construct a correlation model and train the correlation model based on the correlation dataset to obtain a water level deformation correlation model; By using a water level deformation correlation model and based on real-time water level changes, defects in the retaining structure are predicted and early warnings are given, and corresponding strategies are derived. Based on the response strategy, the defects in the building envelope are reinforced.

7. A construction method for deep foundation pit construction using existing structures according to claim 6, characterized in that, The process of constructing the correlation model and training it based on the correlation dataset to obtain the water level deformation correlation model includes the following steps: The associated dataset is divided into a training set and a validation set; Initialize the association model and train it using the training set and cross-entropy loss function; Based on the coefficient of determination and the validation set, the prediction accuracy of the trained correlation model is evaluated, and the trained correlation model is optimized according to the evaluation results to obtain the water level deformation correlation model.

8. A construction method for deep foundation pit construction using existing structures according to claim 6, characterized in that, The method of using a water level deformation correlation model to predict and warn of defects in the retaining structure based on real-time water level changes, and obtaining corresponding strategies, includes the following steps: Acquire real-time water level data and real-time deformation data, and perform preprocessing; By using a water level deformation correlation model, the preprocessed real-time water level data is analyzed to obtain the defect prediction results of the retaining structure. Based on the design parameters of the foundation pit and the actual construction situation, different levels of early warning thresholds are set; Based on the defect prediction results of the building envelope and the set early warning threshold, a response strategy is generated.

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