Construction method for rapid underwater soil taking of long and narrow foundation pit

Abstract

The construction method comprises the steps that S1, a rail system is laid along the longitudinal top of the foundation pit, a gantry crane capable of moving in a full-stroke mode is installed, multiple sets of grab buckets are hung below a cross beam of the gantry crane, and a rotary milling head module capable of being rapidly disassembled and assembled is arranged; s2, mounting an underwater detection device at the bottom of the grab bucket; s3, during excavation, the grab buckets on the two sides synchronously excavate a soil body within the range of 1-2 m away from the enclosure structure, and then the excavation is gradually propelled to the center of the foundation pit according to the state of the soil body; and S4, after the grab bucket is full of soil, the grab bucket is lifted to the position above the water surface, the soil is unloaded into a soil collecting pit or a transport vehicle arranged on one side of the foundation pit, and excavation is repeated till the designed pit bottom elevation is reached. Through cooperative operation of the rail type gantry crane and the multiple grab buckets, underwater detection real-time feedback and rapid switching of milling and grabbing modes, intelligent control and continuous efficient construction of underwater soil sampling of the long and narrow foundation pit are achieved, adaptability to complex underwater geology is remarkably improved, and excavation unbalance and hydraulic disturbance risks are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of foundation pit construction technology, specifically to a construction method for rapid underwater soil extraction in a long and narrow foundation pit. Background Technology

[0002] In underwater construction of long and narrow foundation pits (such as open-cut sections of subways, pipe gallery foundation pits, strip foundation pits, and rail transit station foundation pits), there are not only significant length-to-width ratio characteristics, resulting in extremely limited construction space on both sides of the foundation pit and difficulty in deploying large machinery and equipment, but also special challenges brought about by the underwater working environment: the underwater soil conditions are unknown, visibility is low, traditional equipment cannot accurately judge the state of the excavation face, and it is easy to cause over-excavation, under-excavation, or imbalance of the excavation face; changes in soil quality cannot be detected in real time, and efficiency is low when encountering hard or abnormal soil layers; multiple transfers further increase the complexity of construction and safety risks, seriously affecting the excavation progress and the stability of the foundation pit.

[0003] In the prior art, such as patent document (CN210562365U), an underwater rock breaking device is disclosed, including a gantry crane, a support frame, a ring track, a breaking mechanism (milling machine and bucket), and a soil removal mechanism (grab bucket). This device is suitable for breaking underwater rocks during caisson sinking construction, but it has the following technical problems: (1) Its ring track structure is only suitable for circular caissons and cannot adapt to the linear characteristics of long and narrow foundation pits; (2) The breaking mechanism and the soil removal mechanism are set separately, which cannot achieve multi-point synchronous soil removal and has low efficiency; (3) It lacks an underwater detection device and cannot perceive the soil condition in real time, which can easily lead to blind excavation; (4) It does not consider the soil balance problem unique to long and narrow foundation pits, which can easily lead to foundation pit instability. Patent document (CN110644505A) discloses a rapid soil removal system and method for ultra-deep vertical shaft foundation pit construction, including a sliding rail gantry crane, a soil collection pit, a temporary protective frame, and a soil collection box. The system is suitable for the construction of ultra-deep vertical shaft foundation pits, but it has the following technical problems: (1) It is designed for small circular or square foundation pits and cannot adapt to the length-to-width ratio of long and narrow foundation pits; (2) It only adopts the single-point soil sampling method and cannot achieve multi-point synchronous soil sampling, which is inefficient; (3) It lacks underwater detection devices and cannot perceive the soil elevation and soil conditions in real time; (4) It does not have the quick switching function of the rotary milling head module and is difficult to deal with underwater hard soil layers; (5) It does not consider the symmetrical excavation requirements unique to long and narrow foundation pits, which can easily cause soil stress imbalance.

[0004] Therefore, there is an urgent need for a rapid underwater soil removal method for narrow and elongated foundation pits that can solve the above problems, so as to improve construction efficiency and ensure the stability and safety of the foundation pit. Summary of the Invention

[0005] To address the aforementioned technical challenges, the present invention aims to provide a construction method for rapid underwater soil extraction in narrow and elongated foundation pits, thereby resolving the aforementioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A construction method for rapid underwater soil removal from a narrow, elongated foundation pit includes the following steps:

[0008] S1: Lay a track system along the top of the longitudinal direction of the foundation pit, install a gantry crane that can move in its entire stroke, suspend 2 to 4 independently controlled grab buckets under the crossbeam of the gantry crane, and configure a rotary milling head module that can be quickly assembled and disassembled;

[0009] S2: An underwater detection device is installed at the bottom of the grab bucket to sense the underwater soil elevation and soil conditions in real time;

[0010] Before excavation, the grab bucket lifting, opening and closing and detection system are debugged. After debugging, the higher soil areas are identified based on the detection data and excavation is carried out first.

[0011] S3: During excavation, the soil within a range of 1 to 2 meters from the retaining structure is first excavated simultaneously by the grab buckets on both sides, and then the excavation is gradually advanced towards the center of the pit according to the condition of the soil.

[0012] S4: After the grab bucket is full of soil, it is lifted above the water surface and the soil is unloaded into the soil collection pit or transport vehicle set up on one side of the foundation pit.

[0013] Furthermore, if hard soil layers are encountered during excavation, making it difficult for the grab bucket to directly extract soil, the operation will be suspended, and a rotary milling head module will be installed to break up the hard soil until it meets the requirements for grab bucket soil extraction before continuing excavation.

[0014] Furthermore, the underwater detection device includes a sonar detector or an underwater camera, which can provide real-time feedback on soil morphology and elevation information.

[0015] Furthermore, the underwater detection device installed at the bottom of the grab bucket is integrated with the grab bucket control system. When the difference in soil elevation is detected to exceed a set threshold, the grab bucket excavation sequence and depth are automatically adjusted to prioritize the treatment of areas with higher elevations.

[0016] Furthermore, the grab bucket is independently controlled by the grab bucket control system, enabling simultaneous soil extraction from multiple points.

[0017] Furthermore, the grab bucket includes a hydraulic grab bucket, a mechanical grab bucket, or a device suitable for underwater soil grabbing.

[0018] The beneficial effects of this invention are:

[0019] (1) By using a gantry crane that can move the entire length of the pipeline, combined with multiple independently controlled hydraulic grabs and underwater detection devices, continuous, multi-point synchronous soil sampling and intelligent sensing of underwater soil in narrow foundation pits are realized, effectively overcoming the problems of difficult positioning, low efficiency and blind excavation of traditional underwater machinery.

[0020] (2) Based on real-time detection data, higher areas are excavated first. Combined with the quick-change function of the rotary milling head module, the excavation mode can be quickly switched in underwater hard soil or obstacle layer conditions, which significantly improves the adaptability and construction continuity under complex geological conditions.

[0021] (3) Based on the symmetrical and balanced excavation based on the detection feedback, the underwater soil stress was released smoothly, avoiding the risk of underwater hydraulic disturbance such as pit overturning, leakage or instability of the retaining structure caused by excessively fast unloading in some areas or excessive soil height difference.

[0022] In summary, this invention achieves intelligent control and continuous, efficient construction of underwater soil extraction in narrow foundation pits through the coordinated operation of a rail-mounted gantry crane and multiple grab buckets, real-time feedback from underwater detection, and rapid switching between milling and grab modes. This significantly improves adaptability to complex underwater geology and effectively avoids the risks of excavation imbalance and hydraulic disturbance. Attached Figure Description

[0023] Figure 1 This is a flowchart of the construction method for rapid soil removal from a narrow and elongated foundation pit according to the present invention;

[0024] Figure 2 This is a cross-sectional schematic diagram of the present invention;

[0025] Figure 3 This is a planar schematic diagram of the present invention;

[0026] In the diagram, 1 is the track system, 2 is the gantry crane, 3 is the grab bucket, 4 is the rotary milling head module, and 5 is the underwater detection device. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0028] like Figures 1 to 3 As shown, the present invention provides a construction method for rapid underwater soil removal from a narrow, elongated foundation pit, comprising the following steps:

[0029] Step 1: Lay a track system 1 along the top of the longitudinal direction of the foundation pit, install a gantry crane 2 that can move in its entire stroke, suspend 2 to 4 sets of grab buckets 3 under the crossbeam of the gantry crane 2, and configure a rotary milling head module 4 that can be quickly assembled and disassembled;

[0030] Step 2: Install underwater detection device 5 at the bottom of the grab bucket to sense the underwater soil elevation and soil conditions in real time; before excavation, debug the lifting, opening and closing and detection systems of the grab bucket 3; after debugging, identify the higher soil areas based on the detection data and excavate them first to keep the soil balanced during the excavation process.

[0031] Step 3: During excavation, the soil within a range of 1 to 2 meters from the retaining structure is excavated simultaneously by the grab buckets 3 on both sides. Then, the excavation is gradually advanced towards the center of the pit according to the condition of the soil.

[0032] Step 4: After grab bucket 3 is full of soil, lift it above the water surface and unload the soil into the soil collection pit or transport vehicle set up on one side of the foundation pit. Repeat the excavation until the designed bottom elevation of the pit is reached.

[0033] Step 5: If a hard soil layer is encountered during excavation and the grab bucket 3 cannot directly remove soil, the operation is suspended, and the rotary milling head module 4 is installed to break the hard soil until it meets the requirements for the grab bucket to remove soil before continuing the excavation.

[0034] Furthermore, the grab bucket 3 lowered by the gantry crane 2 is independently controlled, enabling simultaneous soil removal from multiple points.

[0035] Furthermore, the grab bucket 3 includes hydraulic grab buckets, mechanical grab buckets, and other equipment suitable for underwater soil grabbing.

[0036] Furthermore, the underwater detection device 5 includes a sonar detector or underwater camera equipment, which can provide real-time feedback on soil morphology and elevation information.

[0037] As can be seen from the above embodiments, the method of the present invention effectively solves the key technical problems in underwater soil extraction construction of narrow and long foundation pits through innovative technologies such as intelligent sensing, symmetrical excavation, and rapid switching, and has significant technical advantages and practical value.

[0038] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A construction method for rapid underwater soil removal from a long and narrow foundation pit, characterized in that, Includes the following steps: S1: Lay a track system along the top of the longitudinal direction of the foundation pit, install a gantry crane that can move in its entire stroke, suspend 2 to 4 independently controlled grab buckets under the crossbeam of the gantry crane, and configure a rotary milling head module that can be quickly assembled and disassembled; S2: Install an underwater detection device at the bottom of the grab bucket to sense the elevation and soil conditions of the underwater soil in real time; before excavation, debug the grab bucket lifting, opening and closing and detection system. After debugging, identify the higher soil areas based on the detection data and excavate them first. S3: During excavation, the soil within a range of 1 to 2 meters from the retaining structure is first excavated simultaneously by the grab buckets on both sides, and then the excavation is gradually advanced towards the center of the pit according to the condition of the soil. S4: After the grab bucket is full of soil, it is lifted above the water surface and the soil is unloaded into the soil collection pit or transport vehicle set up on one side of the foundation pit.

2. The construction method for rapid underwater soil removal from a narrow, elongated foundation pit according to claim 1, characterized in that, If a hard soil layer is encountered during excavation, making it difficult for the grab bucket to directly extract soil, the operation is suspended, and a rotary milling head module is installed to break up the hard soil until it meets the requirements for grab bucket soil extraction before continuing excavation.

3. The construction method for rapid underwater soil removal from a narrow, elongated foundation pit according to claim 1, characterized in that, The underwater detection device 5 includes a sonar detector or an underwater camera, which can provide real-time feedback on soil morphology and elevation information.

4. The construction method for rapid underwater soil removal from a narrow, elongated foundation pit according to claim 1, characterized in that, The underwater detection device installed at the bottom of the grab bucket is integrated with the grab bucket control system. When the difference in soil elevation is detected to exceed the set threshold, the grab bucket excavation sequence and depth are automatically adjusted to prioritize the treatment of areas with higher elevation.

5. The construction method for rapid underwater soil removal from a narrow, elongated foundation pit according to claim 1, characterized in that, The grab bucket is independently controlled by the grab bucket control system, enabling simultaneous soil extraction from multiple points.

6. The construction method for rapid underwater soil removal from a narrow, elongated foundation pit according to claim 1, characterized in that, The grab bucket includes a hydraulic grab bucket, a mechanical grab bucket, or a device suitable for underwater soil grabbing.

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