Device for eliminating side frictional resistance of drilled pile at excavation section of deep foundation pit

Abstract

The utility model discloses a device for eliminating side frictional resistance of a drilled pile at an excavation section of a deep foundation pit, which comprises a main reinforcement cage, an isolation reinforcement cage, a steel wire mesh, a nylon mesh, a straw mat mesh and an isolation steel casing, the main reinforcement cage is arranged in the isolation reinforcement cage, the lower end of the main reinforcement cage extends to the lower part of the isolation reinforcement cage, and the isolation steel casing is arranged in the isolation reinforcement cage. The steel wire net is arranged on the outer surface of the isolation steel reinforcement cage, the nylon net is arranged on the outer surface of the steel wire net, the straw mat net is arranged on the outer surface of the nylon net, and the isolation steel casing is arranged on the main steel reinforcement cage in a sleeving mode. The isolation reinforcement cage, the steel wire mesh, the nylon mesh, the straw mat mesh and the isolation steel casing are all located in the isolation steel casing. According to the method, the side frictional resistance between the pile and the surrounding rock is removed, so that the purpose of removing the side frictional resistance of the excavation section of the ultra-deep foundation pit is achieved, the pile side frictional resistance of the non-effective pile length section of the engineering pile is conveniently and effectively isolated, and it is ensured that static load test data collection is real and reliable.

Description

Technical Field

[0001] The utility model relates to the technical field of bored piles, in particular to a device for eliminating the side friction resistance of bored piles in a deep foundation pit excavation section. Background Art

[0002] With the rapid development of urban construction, super high-rise buildings have gradually become a new trend in construction, which has put forward higher and higher requirements on the bearing capacity of pile foundations. In order to accurately calculate the bearing capacity of pile foundations and provide accurate design and process parameters for the design and later construction of pile foundations, it is particularly important to conduct static load tests on pile foundations before the formal construction of foundation engineering piles. However, in actual engineering practice, due to the limitations of deep foundation pit support structures and the influence of factors such as excavation depth, it is difficult to conduct static load tests on large-tonnage engineering test piles after the foundation pit is excavated to the bottom of the foundation pit.

[0003] At present, the vertical static load test of pile foundation is usually carried out on the ground, but the vertical ultimate bearing capacity data of the single pile obtained in this way includes the pile side friction resistance of the stratum in the foundation pit excavation section (i.e., the non-effective pile length part), so it is difficult to truly reflect the actual bearing capacity data of the engineering pile after the foundation pit excavation. In order to solve this problem, a device is needed that can eliminate the side friction resistance of the bored pile in the deep foundation pit excavation section, so as to more accurately evaluate the actual bearing capacity of the engineering pile after the foundation pit excavation. Utility Model Content

[0004] The purpose of the utility model is to solve the above technical problems, thereby providing a device for eliminating the side friction resistance of bored piles in the excavation section of a deep foundation pit;

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] The utility model provides a device for eliminating the side friction resistance of bored piles in the deep foundation pit excavation section.

[0007] It includes a main steel cage, an isolation steel cage, a wire mesh, a nylon mesh, a straw mesh, and an isolation steel casing. The main steel cage is arranged in the isolation steel cage, and the lower end of the main steel cage extends to the bottom of the isolation steel cage. The outer surface of the isolation steel cage is provided with the wire mesh, the outer surface of the wire mesh is provided with the nylon mesh, and the outer surface of the nylon mesh is provided with the straw mesh. The isolation steel casing is sleeved on the main steel cage, and the isolation steel cage, the wire mesh, the nylon mesh, the straw mesh, and the isolation steel casing are all located in the isolation steel casing. An isolation steel cage reinforcement block is provided between the isolation steel casing and the isolation steel cage, and a main steel cage reinforcement block is provided between the isolation steel casing and the main steel cage.

[0008] Optionally, the isolation steel cage reinforcement blocks are evenly distributed along the length direction of the isolation steel cage, and each of the isolation steel cage reinforcement blocks is fixed to the isolation steel cage by welding or binding.

[0009] Optionally, the main steel cage reinforcement blocks are evenly distributed along the length direction of the main steel cage, and each of the main steel cage reinforcement blocks is fixed to the main steel cage by welding or binding.

[0010] Optionally, the wire mesh, nylon mesh and straw mat mesh are all fixed to the outer surface of the isolation steel cage by tying or sewing to form a multi-layer protective structure.

[0011] Optionally, a lifting ring is provided at the upper end of the isolation steel casing to facilitate lifting the device as a whole into the deep foundation pit excavation section, and a blade foot is provided at the lower end of the isolation steel casing to facilitate inserting the device into the soil.

[0012] Optionally, a first fixing ring and a second fixing ring are provided at the upper end of the main steel cage, the first fixing ring is used to fix the main steel cage and the nylon mesh sleeve together, and the second fixing ring is used to fix the main steel cage and the straw mat mesh sleeve together.

[0013] Beneficial effects of the utility model

[0014] This application eliminates the lateral friction between the pile and the surrounding rock, thereby achieving the purpose of eliminating the lateral friction in the ultra-deep foundation pit excavation section, conveniently and effectively isolating the lateral friction of the pile in the non-effective pile length section of the engineering pile, ensuring the authenticity and reliability of the static load test data collection, and the effect is remarkable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of the structure of the utility model.

[0016] Explanation of the accompanying numbers: 1-floor; 2-main steel cage; 3-isolation steel cage; 4-wire mesh; 5-nylon mesh; 6-grass mat mesh; 7-isolation steel cage reinforcement block; 8-foundation pit bottom; 9-casing wall; 10-main steel cage reinforcement block. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] Example

[0019] like Figure 1 As shown, the utility model provides a device for eliminating the side friction resistance of bored piles in the deep foundation pit excavation section.

[0020] It includes a main steel cage 2, an isolation steel cage 3, a wire mesh 4, a nylon mesh 5, a straw mesh 6, and an isolation steel casing 9, wherein the main steel cage 2 is arranged in the isolation steel cage 3, and the lower end of the main steel cage 2 extends to the bottom of the isolation steel cage 3, the outer surface of the isolation steel cage 3 is provided with the wire mesh 4, the outer surface of the wire mesh 4 is provided with the nylon mesh 5, and the outer surface of the nylon mesh 5 is provided with the straw mesh 6, and the isolation steel casing 9 is sleeved on the main steel cage 2, and the isolation steel cage 3, the wire mesh 4, the nylon mesh 5, the straw mesh 6, and the isolation steel casing 9 are all located in the isolation steel casing 9, an isolation steel cage reinforcement block 7 is arranged between the isolation steel casing 9 and the isolation steel cage 3, and a main steel cage reinforcement block 10 is arranged between the isolation steel casing 9 and the main steel cage 2.

[0021] The isolation steel cage reinforcement blocks 7 are evenly distributed along the length direction of the isolation steel cage 3, and each of the isolation steel cage reinforcement blocks 7 is fixed to the isolation steel cage 3 by welding or binding, ensuring that the isolation steel cage reinforcement blocks 7 are evenly distributed along the length direction, which is beneficial to the stability of the overall structure and the uniform transmission of bearing capacity. The reinforcement blocks are fixed to the isolation steel cage 3 by welding or binding, which enhances the stability of the device and prevents displacement or falling off during the test.

[0022] The main steel cage reinforcement blocks 10 are evenly distributed along the length direction of the main steel cage 2, and each of the main steel cage reinforcement blocks 10 is fixed to the main steel cage 2 by welding or binding. The reinforcement blocks are evenly fixed along the length direction of the main steel cage 2 by welding or binding, thereby improving the overall stability and bearing performance of the device.

[0023] The wire mesh 4, nylon mesh 5 and straw mat mesh 6 are all fixed on the outer surface of the isolation steel cage 3 by binding or sewing to form a multi-layer protective structure. The multi-layer mesh is fixed on the outer surface of the isolation steel cage 3 by binding or sewing to form an effective protective barrier to prevent external factors from interfering with and damaging the internal structure of the device. The multi-layer protective structure helps to maintain the stability and consistency of the device, thereby improving the accuracy of the static load test results.

[0024] A lifting ring is provided at the upper end of the isolation steel casing 9, which is convenient for lifting the entire device into the deep foundation pit excavation section, and a blade foot is provided at the lower end of the isolation steel casing 9, which is convenient for inserting the device into the soil. The design of the lifting ring enables the entire device to be conveniently lifted into the deep foundation pit excavation section, thereby improving construction efficiency. The design of the blade foot helps the isolation steel casing 9 to be smoothly inserted into the soil, thereby ensuring the stability and safety of the device during installation.

[0025] A first fixing ring and a second fixing ring are provided at the upper end of the main steel cage 2. The first fixing ring is used to fix the main steel cage 2 and the nylon net 5 together, and the second fixing ring is used to fix the main steel cage 2 and the straw mat net 6 together. The main steel cage 2, the nylon net 5 and the straw mat net 6 are fixed together by the first fixing ring and the second fixing ring, which further enhances the overall stability and bearing performance of the device. The stable structural design helps to prevent safety hazards such as collapse or slippage of the device during the test and ensure the safety of the test personnel.

[0026] The present application can effectively eliminate the lateral friction resistance of bored piles in the deep foundation pit excavation section, thereby more accurately evaluating the actual bearing capacity of the engineering piles after the foundation pit excavation. The device is mainly composed of a main steel cage 2, an isolation steel cage 3, a wire mesh 4, a nylon mesh 5, a straw mat mesh 6, an isolation steel casing 9, etc. The stability and protective effect of the device in the deep foundation pit excavation section are ensured by setting a multi-layer protective structure and reinforcement blocks.

[0027] This application includes the following steps during use:

[0028] Device preparation:

[0029] According to the design requirements, the main steel cage 2 and the isolation steel cage 3 are made, and the main steel cage 2 is set in the isolation steel cage 3, ensuring that the lower end of the main steel cage 2 extends to the bottom of the isolation steel cage 3, and the wire mesh 4, nylon mesh 5 and straw mat mesh 6 are arranged in sequence on the outer surface of the isolation steel cage 3 to form a multi-layer protection structure, and the isolation steel casing 9 is sleeved on the main steel cage 2, ensuring that the isolation steel cage 3, the wire mesh 4, the nylon mesh 5, the straw mat mesh 6, and the isolation steel casing 9 are all located in the isolation steel casing 9, an isolation steel cage reinforcement block 7 is arranged between the isolation steel casing 9 and the isolation steel cage 3, and a main steel cage reinforcement block 10 is arranged between the isolation steel casing 9 and the main steel cage 2.

[0030] Device hoisting and fixing:

[0031] By using the lifting ring at the upper end of the isolation steel casing 9, the entire device is lifted from the ground 1 to the bottom of the deep foundation pit 8 in the excavation section of the deep foundation pit. By adjusting the position of the device, its alignment and stability with the bored piles are ensured. By using the first fixing ring and the second fixing ring at the upper end of the main steel cage 2, the main steel cage 2 is fixed together with the nylon net 5 and the straw mat net 6 to further enhance the stability of the device.

[0032] Static load test:

[0033] After the device is installed, a static load test of the pile foundation is carried out. By applying a static load, the bearing capacity data of the pile foundation is observed and recorded. Due to the presence of the device, the influence of the stratum in the deep foundation pit excavation section on the side friction of the bored piles is effectively eliminated. Therefore, the bearing capacity data obtained is closer to the actual bearing capacity of the engineering piles after the foundation pit excavation.

[0034] Data Collection and Analysis:

[0035] Collect the bearing capacity data obtained during the static load test, analyze and process the data to obtain more accurate pile foundation bearing capacity assessment results. Based on the assessment results, provide accurate design and process parameters for the pile foundation design and subsequent construction.

[0036] This application eliminates the lateral friction between the pile and the surrounding rock, thereby achieving the purpose of eliminating the lateral friction in the ultra-deep foundation pit excavation section, conveniently and effectively isolating the lateral friction of the pile in the non-effective pile length section of the engineering pile, ensuring the authenticity and reliability of the static load test data collection, and the effect is remarkable.

[0037] This application eliminates the lateral friction resistance of bored piles in the deep foundation pit excavation section, making the bearing capacity data obtained from the static load test more real and accurate, and can more accurately reflect the actual bearing capacity of the engineering piles after the foundation pit excavation, providing reliable data support for the design and subsequent construction of the pile foundation.

[0038] The design of the device takes stability and protection effect into consideration. The multi-layer protection structure and reinforcement blocks effectively prevent potential safety hazards such as collapse and slippage that may occur during the test, thus ensuring the safety of the test personnel.

[0039] This application is applicable to deep foundation pit excavation sections of different depths and geological conditions, can meet the needs of different projects for pile foundation bearing capacity assessment, and has broad application prospects.

[0040] Through the technical means of this application, the bearing capacity of the pile foundation can be accurately evaluated during the foundation pit excavation stage, avoiding remedial measures due to insufficient bearing capacity in the later stage, improving construction efficiency and reducing project costs.

[0041] Finally, it should be noted that the above is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A device for eliminating the side friction resistance of bored piles in deep foundation pit excavation section, characterized in that: It includes a main steel cage, an isolation steel cage, a wire mesh, a nylon mesh, a straw mesh, and an isolation steel casing. The main steel cage is arranged in the isolation steel cage, and the lower end of the main steel cage extends to the bottom of the isolation steel cage. The outer surface of the isolation steel cage is provided with the wire mesh, the outer surface of the wire mesh is provided with the nylon mesh, and the outer surface of the nylon mesh is provided with the straw mesh. The isolation steel casing is sleeved on the main steel cage, and the isolation steel cage, the wire mesh, the nylon mesh, the straw mesh, and the isolation steel casing are all located in the isolation steel casing. An isolation steel cage reinforcement block is provided between the isolation steel casing and the isolation steel cage, and a main steel cage reinforcement block is provided between the isolation steel casing and the main steel cage.

2. The device for eliminating the side friction of bored piles in deep foundation pit excavation section according to claim 1 is characterized in that: The isolation steel cage reinforcement blocks are evenly distributed along the length direction of the isolation steel cage, and each of the isolation steel cage reinforcement blocks is fixed to the isolation steel cage by welding or binding.

3. The device for eliminating the side friction of bored piles in deep foundation pit excavation section according to claim 1 is characterized in that: The main steel cage reinforcement blocks are evenly distributed along the length direction of the main steel cage, and each of the main steel cage reinforcement blocks is fixed to the main steel cage by welding or binding.

4. The device for eliminating the side friction of bored piles in deep foundation pit excavation section according to claim 1 is characterized in that: The wire mesh, nylon mesh and straw mat mesh are all fixed on the outer surface of the isolation steel cage by tying or sewing to form a multi-layer protection structure.

5. The device for eliminating the side friction of bored piles in deep foundation pit excavation section according to claim 1 is characterized in that: The upper end of the isolation steel casing is provided with a lifting ring, which is convenient for lifting the device as a whole into the deep foundation pit excavation section, and the lower end of the isolation steel casing is provided with a blade foot, which is convenient for inserting the device into the soil.

6. The device for eliminating the side friction of bored piles in deep foundation pit excavation section according to claim 1 is characterized in that: A first fixing ring and a second fixing ring are provided at the upper end of the main steel cage, the first fixing ring is used to fix the main steel cage and the nylon mesh sleeve together, and the second fixing ring is used to fix the main steel cage and the straw mat mesh sleeve together.

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