Construction piling and sampling integrated steel sheet pile bottom soil layer detection method and device

Abstract

The invention discloses a construction piling and sampling integrated steel sheet pile bottom soil layer detection method and device. A steel pipe for soil sampling is installed on a steel sheet pile, the steel sheet pile is beaten, the steel sheet pile and the steel pipe for soil sampling are vertically beaten to the designed bottom elevation, and in the beating process, a soil core continuously enters the steel pipe for soil sampling on the steel sheet pile; after the steel sheet pile reaches the designed bottom elevation, the steel sheet pile and the steel pipe for soil sampling are pulled out, and the soil core is poured out of the steel pipe for soil sampling; according to the taken-out pile bottom soil core, whether the soil layer meets the design requirement or not is judged; compared with a traditional geological drilling coring method for obtaining the subsoil layer condition, the sampling construction period is shorter, meanwhile, during piling, the link that drilling operation personnel and piling operation personnel alternately enter a site is omitted, the link that drilling equipment and piling equipment alternately enter the site is omitted, the construction link is omitted, and the construction cost is reduced. The engineering efficiency is improved, and the engineering cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of water conservancy and geotechnical engineering, and particularly relates to a steel sheet pile bottom soil layer detection device and method integrated with construction piling and sampling. Background Art

[0002] Steel sheet piles, due to their advantages of rapid construction, reusability, and strong adaptability, are widely used in anti-seepage and foundation pit support projects. In water conservancy projects, steel sheet piles are used for river bank protection, embankment reinforcement, and cofferdam anti-seepage. In environmental protection projects, steel sheet piles can be used to isolate contaminated sites and form anti-seepage walls in landfills. In underground projects, steel sheet piles are used as water-blocking curtains in structures such as basements. Furthermore, steel sheet piles are commonly used in temporary support projects such as construction foundation pits, bridges, and docks. During the driving process, accurate understanding of the soil conditions beneath the piles is crucial to ensuring effective anti-seepage measures, pile bearing capacity, verticality, and construction safety.

[0003] Currently, three main methods are commonly used in engineering projects to identify the soil layer at the bottom of steel sheet piles. The first is the geological prediction method, which infers soil layer distribution based on surrounding geological drilling data. However, due to the discrete nature of the survey points, it is difficult to reflect local stratigraphic changes. The second is the vibration hammer parameter analysis method, which indirectly determines soil layer properties by recording the number of hammer strikes or changes in penetration velocity. However, this method relies on construction experience and is easily affected by factors such as equipment power and pile friction, making it difficult to accurately identify specific soil layers. The third is the geological drilling and coring method. Currently, obtaining soil layer information through drilling and coring generally takes two days. While this method can accurately obtain soil layer information, it requires suspending steel sheet pile construction and conducting separate surveys, which is time-consuming and cannot meet the requirements of continuous steel sheet pile installation projects, seriously affecting construction efficiency and being costly. All of these methods have significant limitations. Empirical judgments lack objective data support, while accurate detection struggles to balance economic efficiency and timeliness. Therefore, how to quickly and accurately determine the subsoil conditions of steel sheet piles while ensuring construction progress has become a key problem restricting the application of steel sheet pile technology.

[0004] To address this issue, there is an urgent need to develop a steel sheet pile bottom soil layer detection device that can not only realize real-time and accurate acquisition of soil layer data, but also has the characteristics of easy operation and low cost, thereby providing reliable technical support for steel sheet pile construction and improving project quality and construction safety. Summary of the Invention

[0005] The purpose of the present invention is to develop a real-time, accurate, low-cost, and easy-to-operate pile bottom soil layer detection device, which can synchronously and accurately identify the pile bottom soil layer during the steel sheet pile construction and piling process, effectively overcoming the disadvantages of traditional methods such as reliance on experience judgment, long time consumption, and high cost, and providing a scientific and reliable soil layer identification method for steel sheet pile construction, thereby ensuring the integrity of the anti-seepage system and the safety of the support structure, and promoting the development of steel sheet pile construction technology.

[0006] To achieve the above objectives, the technical solution of the present invention is: A method for detecting the subsoil layer of steel sheet piles with integrated construction piling and sampling, the method comprising: Install the steel pipe for soil extraction on the steel sheet pile, hammer the steel sheet pile, and vertically drive the steel sheet pile and the steel pipe for soil extraction to the designed bottom elevation. During the hammering process, the soil core continuously enters the steel pipe for soil extraction on the steel sheet pile; After the steel sheet pile reaches the designed bottom elevation, the driving and pulling machine clamps the steel sheet pile, pulls out the steel sheet pile and the steel pipe used for soil extraction, and pours the soil core out of the steel pipe used for soil extraction; According to the soil core taken out from the pile bottom, judge whether the soil layer meets the design requirements; If the designed soil layer at the bottom of the pile has been reached, large-scale piling will be carried out. If the designed soil layer has not been reached, the pile bottom design elevation will be adjusted and the soil excavation steps will be repeated until it is confirmed that the pile bottom soil layer meets the design requirements.

[0007] Furthermore, during the hammering process, a plurality of anti-falling baffles in the steel pipe used for soil excavation are pushed open by the pressure of the soil layer, and the soil core continues to enter the steel pipe used for soil excavation.

[0008] Furthermore, during the process of pulling out the steel sheet piles and the steel pipes for taking soil, if the soil core fits tightly against the inner wall of the steel pipes for taking soil, the soil core will not fall off when the steel sheet piles are lifted, and the soil core can be completely taken out; if the soil is loose, the soil core will fall downward due to vibration when the steel sheet piles are lifted, and when the soil core falls to the position of the anti-falling baffle opened inside the steel pipe for taking soil, the anti-falling baffle will be expanded to a horizontal position to prevent the soil core from falling off.

[0009] A steel sheet pile bottom soil layer detection device for implementing the detection method includes a soil-borrowing steel pipe, and an anti-falling baffle is installed at the lower end of the soil-borrowing steel pipe. When the anti-falling baffle is subjected to external force, the anti-falling baffle rotates inside the soil-borrowing steel pipe. The top end of the soil-borrowing steel pipe is connected to an upper steel pipe, and the upper steel pipe is fixedly connected to the steel sheet pile. The upper steel pipe and the soil-borrowing steel pipe are both located on the inner side of the steel sheet pile with a U-shaped cross-section.

[0010] Furthermore, a limiting boss is installed at the lower end of the soil-taking steel pipe, and an anti-falling baffle is located above the limiting boss, and the anti-falling baffle is hingedly connected to the limiting boss.

[0011] Furthermore, three limiting bosses are evenly spaced and installed at the lower end of the soil-borrowing steel pipe. The three limiting bosses are welded to the inner wall of the soil-borrowing steel pipe. A limiting boss is arranged every 120° inside the soil-borrowing steel pipe, and the limiting bosses are arranged vertically inside the soil-borrowing steel pipe.

[0012] Furthermore, each of the anti-falling baffles is a high-carbon steel sector with a central angle of 120°.

[0013] Furthermore, the top surface of each of the limiting bosses is hingedly connected to an anti-falling baffle, and a hinge axis is arranged on the top surface of the limiting boss. The hinge axis is located on the side of the top surface of the limiting boss close to the side wall of the soil-extracting steel pipe, that is, the hinge axis is located on the side of the top surface of the limiting boss away from the center of the soil-extracting steel pipe. A through hole is arranged at the end of the anti-falling baffle, and the through hole at the end of the anti-falling baffle is hingedly connected to the hinge axis on the top surface of the limiting boss. When the anti-falling baffle rotates from top to bottom, it is limited by the limiting action of the limiting boss, and the anti-falling baffle no longer rotates downward when it is expanded to a horizontal position.

[0014] Furthermore, the lower outer surface of the upper steel pipe is provided with a threaded inner threaded opening, and the upper outer surface of the soil-taking steel pipe is provided with a threaded outer threaded opening, and the threaded outer threaded opening matches the threaded inner threaded opening on the lower outer surface of the upper steel pipe.

[0015] Furthermore, the axis of the upper steel pipe coincides with the center line of the steel sheet pile.

[0016] The technical solution of the present invention has the following technical effects: 1. The traditional geological drilling and coring method is used to obtain the subsoil conditions, which generally takes about two days. This is time-consuming and cannot meet the engineering requirements of continuous steel sheet pile construction and piling, seriously affecting construction efficiency. Compared with the traditional drilling and sampling method, this application shortens the time for determining the subsoil layer of steel sheet piles by more than 90%, and shortens the construction period from two days of traditional drilling and coring to two hours, significantly improving construction efficiency.

[0017] 2. If the traditional geological coring method is used to obtain the subsoil conditions, before construction and piling, drilling personnel must first enter the site and use drilling equipment. When the composite design requirements of the subsoil are known, piling operations can be carried out. However, the present application obtains the subsoil conditions by piling, and the piling operations are carried out directly by the piling operators. Compared with the traditional geological coring method for obtaining the subsoil conditions, the present invention eliminates the drilling operation during piling, which saves construction links, improves engineering efficiency, and reduces engineering costs.

[0018] 3. The present invention completes the sampling of the bottom soil layer of the steel sheet pile by piling. Through the three-in-one operation of "construction piling-detection-sampling", the construction links are reduced and the construction team is simplified. Compared with traditional drilling sampling costs, the present invention saves about 95% or more.

[0019] 4. The present invention provides a real-time, accurate, low-cost, and easy-to-operate pile bottom soil layer detection device that is synchronized with steel sheet pile construction and piling. The present invention has good application prospects and is suitable for all scenarios where steel sheet piles are used. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a three-dimensional schematic diagram of the detection device assembly of the present invention.

[0021] Figure 2 This is a cross-sectional view of the detection device of the present invention when the anti-falling baffle is opened.

[0022] Figure 3 (a) is a structural diagram of the soil-excavating steel pipe when the anti-falling baffle of the present invention is closed.

[0023] Figure 3 (b) is a structural diagram of the soil-excavating steel pipe when the anti-falling baffle of the present invention is opened.

[0024] Figure 4 It is a plan view of the limiting boss of the present invention.

[0025] Among them: steel sheet pile 1; upper steel pipe 2; soil-boring steel pipe 3; limiting boss 31; anti-falling baffle 32; threaded external thread 33. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] The detection device of the present invention is used to detect the soil condition at the bottom of the steel sheet pile. Figure 1 As shown, the steel sheet pile subsoil layer detection device integrated with construction piling and sampling of the present invention comprises a steel sheet pile 1, an upper steel pipe 2 and a soil sampling steel pipe 3.

[0028] In the present invention, the steel sheet pile 1 adopts a standard Larsen steel sheet pile, and its size and material are in accordance with design requirements. The cross section of the steel sheet pile 1 is U-shaped. In a specific embodiment, the steel sheet pile is 9 meters long.

[0029] The upper steel pipe 2 is made of Q335B seamless steel pipe with an outer diameter D of 140 mm and a wall thickness t of 8 mm. The length is 60 cm shorter than the steel plate 1 . The lower outer surface of the upper steel pipe 2 is provided with a threaded inner thread port.

[0030] The soil-excavation steel pipe 3 comprises a steel pipe, a limiting boss 31, and an anti-dropout baffle 32. Made of Q335B seamless steel pipe, the soil-excavation steel pipe 3 has an outer diameter D of 140 mm, a wall thickness t of 8 mm, and a length of 60 cm. A threaded external opening 33 is provided on the upper outer surface of the soil-excavation steel pipe 3, which mates with the threaded internal opening on the lower outer surface of the upper steel pipe 2. There are three limiting bosses 31 welded to the inner wall of the soil-excavation steel pipe 3, with one located every 120°. The limiting bosses 31 are arranged vertically within the soil-excavation steel pipe 3 and are welded from steel plates. They are hollow wedge-shaped structures with a top width of 30 mm, a top length of 40 mm, and a height of 50 mm. The steel plate thickness of the hollow wedge structure is 5 mm. There are three anti-drop baffles 32 in total. Each anti-drop baffle 32 is a high-carbon steel fan-shaped baffle with a central angle of 120°. The three anti-drop baffles 32 form an approximately circular shape inside the soil-extracting steel pipe 3 to block the opening at the bottom of the soil-extracting steel pipe 3. The thickness of each anti-drop baffle 32 is 5mm. Each anti-drop baffle 32 is hingedly connected to the top surface of a limiting boss 31. A hinge axis can be set on the top surface of the limiting boss 31. The hinge axis is located on the side of the top surface of the limiting boss 31 close to the side wall of the soil-extracting steel pipe 3. A through hole is set at the end of the anti-drop baffle 32, and the through hole is hingedly connected to the hinge axis. When the anti-drop baffle 32 rotates from top to bottom, it is limited by the limiting boss 31. When the anti-drop baffle 32 is expanded to the horizontal position, it no longer rotates downward.

[0031] The upper steel pipe 2 is welded to the steel sheet pile 1. The steel sheet pile 1 has a U-shaped cross-section, and the upper steel pipe 2 is located inside the U-shaped steel sheet pile 1. The axis of the upper steel pipe 2 coincides with the centerline of the Larsen steel sheet pile. Full welds are made every 1.5 meters on both sides, with a weld height of no less than 6 mm and a weld length of no less than 5 cm per section. After welding is completed, the soil-boring steel pipe 3 is tightened to the upper steel pipe 2 using threaded connections.

[0032] In the present invention, after the upper steel pipe is connected to the soil-borrowing steel pipe, the upper steel pipe is welded to the steel sheet pile. The vertical load is mainly borne by the steel sheet pile. The upper steel pipe and the soil-borrowing steel pipe are both located on the inner side of the steel sheet pile with a U-shaped cross-section. During the hammering process, most of the horizontal load is borne by the steel sheet pile with a U-shaped cross-section, which can reduce the stiffness requirements for the upper steel pipe and the soil-borrowing steel pipe.

[0033] The principle of using the detection device of the present invention to sample the subsoil layer at the bottom of the pile is as follows: Injection stage: the anti-falling baffle 32 is automatically opened by the upward soil support, and the soil core smoothly enters the soil steel pipe 3.

[0034] During the extraction phase, if the soil core is tightly bonded to the inner wall of the steel pipe 3, the core will not fall out when the detection device is lifted, allowing for complete extraction. If the soil is loose, the core may vibrate downward during extraction and fall out. When the core falls to the open anti-fall baffle, the baffle automatically returns to its closed position, free from support from below and compression from above. Furthermore, the baffle 32, restrained by the limiting boss 31, unfolds to a horizontal position, preventing the core from falling out.

[0035] Soil sampling stage: After the detection device is pulled out as a whole, unscrew the lower soil sampling steel pipe 3, pour out the soil core upwards, identify the soil layer at the bottom of the pile, and further confirm whether the soil layer at the bottom of the steel sheet pile meets the design requirements.

[0036] The method for realizing subsoil layer detection by the pile bottom subsoil layer detection device of the present invention is as follows: 1. Procurement and production of device components: Purchase raw materials such as steel sheet piles 1, upper steel pipe 2, upper steel pipe 2, soil-boring steel pipe 3, soil-boring steel pipe 3, fan-shaped anti-falling baffle 31 and limiting boss 32, and steel plates and hinge structures required. Process them according to size, and match the inner thread of upper steel pipe 2 with the outer thread of soil-boring steel pipe 3. The steel sheet piles generally used in pile bottom soil layer detection devices are 6m longer than the maximum designed pile length to meet the requirements of a larger sampling depth.

[0037] 2. Device Assembly ①Install the anti-drop baffle 32. The three anti-drop baffles are hingedly installed on the limiting boss 31, and the opening and closing flexibility of the anti-drop baffles is checked to ensure that the anti-drop baffles can be smoothly pushed open when the soil layer enters the soil steel pipe 3 during injection; ② Welding of the limiting boss 31. The limiting boss 32 is welded from steel plates. Three assembled limiting bosses with anti-drop baffles are welded to the inner bottom side of the soil-boring steel pipe 3. A limiting boss 31 is installed every 120° along the circumferential direction to ensure that the weld strength meets the requirements for the impact load. ③ Welding of the upper steel pipe 2. The upper steel pipe 2 is welded vertically to the inner side of the steel sheet pile 1 with the thread end facing downwards, keeping the axis of the steel pipe aligned with the axis of the steel sheet pile. Welding is performed on both sides of the contact area between the steel pipe and the steel sheet pile every 1.5m. The weld height is not less than 6mm and the weld section length is not less than 50mm. ④ Connect the soil steel pipe 3. Screw the soil steel pipe 3 into the bottom of the upper steel pipe 2, ensuring that the threaded connection is tight and not loose. In the present invention, it is also possible to first connect the upper steel pipe 2 to the soil steel pipe 3 and then weld the upper steel pipe 2 to the inside of the steel sheet pile 1.

[0038] ⑤Quality inspection: Check all welding points and hinged parts to ensure that the structure is firm and the anti-drop baffle is moving without any jamming.

[0039] 3. Device injection: A hydraulic crawler-type driving machine is used to hammer the steel sheet pile 1, and the entire detection device is vertically injected to the designed bottom elevation. During the injection process, the soil pressure pushes open the anti-fall baffle 32, and the soil core continues to enter the soil sampling steel pipe 3 and the upper steel pipe 2. In the present invention, the steel sheet pile 1 is clamped by the hydraulic crawler-type driving machine, and the entire detection device is vertically injected to the designed bottom elevation by pressing.

[0040] 4. Pile pulling and coring: After the entire detection device reaches the designed bottom elevation, the hydraulic crawler-type pulling machine is clamped on the steel sheet pile 1, and the detection device is slowly pulled out by the hydraulic crawler-type pulling machine to minimize disturbance of the soil core; unscrew the soil extraction steel pipe 3 and pour out the internal soil core; if the soil core is stuck, use a wooden stick to push it upward from the bottom of the steel pipe 3 to ensure that the soil core is completely removed.

[0041] 5. Determine the soil layer: Geological engineers determine whether the soil layer meets the design requirements based on the soil cores taken from the pile bottom.

[0042] 6. Large-scale injection: If the designed pile bottom soil layer requirements have been met, large-scale piling can be carried out. At this time, ordinary Larsen steel sheet piles can be used for piling. At this time, steel sheet piles without upper steel pipes and soil-taking steel pipes can be used. If the designed soil layer has not been reached, repeat the above steps 3-5, and adjust the pile bottom elevation step by step. Generally, the pile bottom elevation should be 2m deeper than the last injection until the pile bottom soil layer meets the design requirements.

[0043] Through the above steps, the detection of the bottom soil layer of the steel sheet pile is completed.

[0044] The above embodiments are merely examples for clarity of explanation and are not intended to limit the embodiments. Those skilled in the art will appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all embodiments here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for detecting the bottom soil layer of steel sheet piles with integrated construction piling and sampling, characterized in that: The method comprises: Installing a steel pipe for soil extraction on the steel sheet pile (1), hammering the steel sheet pile (1), and vertically driving the steel sheet pile (1) and the steel pipe for soil extraction to the designed bottom elevation, wherein during the hammering process, the soil core continuously enters the steel pipe for soil extraction on the steel sheet pile (1); After the steel sheet pile (1) reaches the designed bottom elevation, the driving and pulling machine clamps the steel sheet pile, pulls out the steel sheet pile (1) and the steel pipe for soil extraction, and pours the soil core out of the steel pipe for soil extraction; According to the soil core taken out from the pile bottom, judge whether the soil layer meets the design requirements; If the designed soil layer at the bottom of the pile has been reached, large-scale piling will be carried out. If the designed soil layer has not been reached, the pile bottom design elevation will be adjusted and the soil excavation steps will be repeated until the soil layer at the bottom of the pile meets the design requirements.

2. The method for detecting the bottom soil layer of steel sheet piles with integrated construction piling and sampling according to claim 1, characterized in that: During the hammering process, a plurality of anti-falling baffles (32) in the steel pipe for soil excavation are pushed open by the pressure of the soil layer, and the soil core continues to enter the steel pipe for soil excavation.

3. The method for detecting the bottom soil layer of steel sheet piles with integrated construction piling and sampling according to claim 1, characterized in that: During the process of pulling out the steel sheet pile (1) and the steel pipe for soil extraction, if the soil core is tightly fitted to the inner wall of the steel pipe for soil extraction, the soil core does not fall off when the steel sheet pile (1) is lifted and can be completely removed; if the soil is loose, the soil core falls off downward due to vibration when the steel sheet pile (1) is lifted, and when the soil core falls off to the position of the anti-falling baffle opened inside the steel pipe for soil extraction, the anti-falling baffle is unfolded to a horizontal position to prevent the soil core from falling off.

4. A steel sheet pile subsoil layer detection device for implementing the detection method according to any one of claims 1 to 3, comprising a soil sampling steel pipe (3), characterized in that: An anti-falling baffle (32) is installed at the lower end of the soil-borrowing steel pipe (3). When the anti-falling baffle (32) is subjected to external force, the anti-falling baffle (32) rotates inside the soil-borrowing steel pipe (3). The top of the soil-borrowing steel pipe (3) is connected to an upper steel pipe (2). The upper steel pipe (2) is fixedly connected to the steel sheet pile (1). The upper steel pipe (2) and the soil-borrowing steel pipe (3) are both located on the inner side of the steel sheet pile (1) with a U-shaped cross-section.

5. The steel sheet pile bottom soil layer detection device according to claim 4, characterized in that: A limiting boss (31) is installed at the lower end of the soil-boring steel pipe (3), and an anti-falling baffle (32) is located above the limiting boss (31). The anti-falling baffle (32) is hingedly connected to the limiting boss (31).

6. The steel sheet pile bottom soil layer detection device according to claim 4, characterized in that: Three limiting bosses (31) are evenly spaced and installed at the lower end of the soil-borrowing steel pipe (3). The three limiting bosses (31) are welded to the inner wall of the soil-borrowing steel pipe (3). One limiting boss (31) is arranged every 120 degrees inside the soil-borrowing steel pipe (3). The limiting bosses (31) are arranged vertically inside the soil-borrowing steel pipe (3).

7. The steel sheet pile bottom soil layer detection device according to claim 6, characterized in that: Each of the anti-falling baffles (32) is a high-carbon steel sector with a central angle of 120°.

8. The steel sheet pile bottom soil layer detection device according to claim 6, characterized in that: The top surface of each of the limiting bosses 31 is hingedly connected to an anti-falling baffle (32), and a hinge shaft is provided on the top surface of the limiting boss (31). The hinge shaft is located on the side of the top surface of the limiting boss (31) close to the side wall of the soil-excavating steel pipe (3). A through hole is provided at the end of the anti-falling baffle (32). The through hole at the end of the anti-falling baffle (32) is hingedly connected to the hinge shaft on the top surface of the limiting boss (31). When the anti-falling baffle (32) rotates from top to bottom, due to the limiting effect of the limiting boss (31), the anti-falling baffle (32) no longer rotates downward when it is unfolded to a horizontal position.

9. The steel sheet pile bottom soil layer detection device according to claim 4, characterized in that: The lower outer surface of the upper steel pipe (2) is provided with a threaded inner threaded opening, and the upper outer surface of the soil-excavating steel pipe (3) is provided with a threaded outer threaded opening (33), and the threaded outer threaded opening (33) matches the threaded inner threaded opening on the lower outer surface of the upper steel pipe (2).

10. The steel sheet pile bottom soil layer detection device according to claim 4, characterized in that: The axis of the upper steel pipe (2) coincides with the center line of the steel sheet pile (1).

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