A bank protection foundation pit enclosure structure

Abstract

The utility model relates to a kind of bank slope protection foundation pit enclosure structure.The current foundation pit enclosure structure exists only as temporary works, cannot balance water and soil pressure and cannot adapt to the problem of water environment construction.The utility model includes lock catch steel pipe pile, interlocking pile structure, corbel and cross brace;The lock catch steel pipe pile is arranged in bank slope periphery;The interlocking pile structure includes pile cap peripheral interlocking pile and bank slope side interlocking pile, the side of the pile cap peripheral interlocking pile close to the lock catch steel pipe pile and the bank slope side interlocking pile are parallel with the lock catch steel pipe pile Setting, and the pile cap peripheral interlocking pile and the bank slope side interlocking pile are all reinforced concrete structure;The corbel is set in the top of the pile cap peripheral interlocking pile, and the cross brace is set in the middle of the corbel.The utility model can continue to be used as bank slope protection structure to prevent bank collapse after main body pile cap pile foundation, bridge pier construction is completed, can effectively balance water and soil pressure, and can adapt to water environment construction.

Description

Technical Field

[0001] This utility model relates to the field of bridge foundation pit protection technology, specifically to a slope protection foundation pit retaining structure. Background Technology

[0002] Currently, bored interlocking piles are generally used as the retaining structure for deep foundation pits. Interlocking piles are pile walls formed by overlapping and interlocking two different types of piles.

[0003] In traditional engineering practices, interlocking pile foundation pit retaining structures are only used as temporary works. After the foundation pit is completed, except for specially designed diaphragm walls that also serve as the main structure, most other types of retaining structures become meaningless in the long-term use phase. Their utilization or contribution to the main structure is generally not considered. The cost of foundation pit retaining structures is quite high. For example, the retaining cost for a 10-meter-deep foundation pit is about 30,000 yuan per linear meter. The cost of retaining structures as temporary auxiliary works is quite considerable. Therefore, interlocking piles are not used as the main structure and are scrapped after the underground building is completed.

[0004] Furthermore, traditional underground structure design methods generally do not consider the sharing of water and soil pressure by interlocking piles. Existing retaining structures are only used as a means to prevent the collapse of the foundation pit. Their role is no longer considered after operation. The effects of landslides and bank collapses after the foundation pit is backfilled on the main structure are no longer considered. They are either demolished or abandoned in their original location. Their performance is not well utilized, resulting in project waste.

[0005] Conventional foundation pit retaining structures are typically implemented on land and cannot be adapted to construction in water environments. For working environments along riverbanks, corresponding bank slope protection works are required to form a construction site. Commonly used methods include gabion cofferdams, earth-rock dams, or island construction, but these methods have poor water-blocking effects and are not economical.

[0006] Therefore, there is an urgent need for a bank slope protection foundation pit retaining structure that can be used for a long time, effectively balance water and soil pressure, and adapt to construction in water environments. Summary of the Invention

[0007] The purpose of this utility model is to provide a slope protection foundation pit retaining structure to at least solve the problems that the current foundation pit retaining structures are only temporary projects, cannot balance water and soil pressure, and cannot adapt to construction in watery environments.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] A slope protection foundation pit retaining structure includes interlocking steel pipe piles, interlocking pile structure, capping beam and cross bracing;

[0010] The locking steel pipe piles are arranged on the outer perimeter of the bank slope;

[0011] The interlocking pile structure includes interlocking piles around the foundation and interlocking piles on the bank slope. The interlocking piles around the foundation near the locking steel pipe pile and the interlocking piles on the bank slope are both arranged parallel to the locking steel pipe pile, and both the interlocking piles around the foundation and the interlocking piles on the bank slope are reinforced concrete structures.

[0012] The cap beam is located on top of the interlocking piles around the foundation, and the cross brace is located in the middle of the cap beam.

[0013] Furthermore, the top of the locking steel pipe pile is higher than the top of the cap beam.

[0014] Furthermore, both the perimeter interlocking piles of the pier cap and the side interlocking piles of the bank slope include multiple type A piles and multiple type B piles, which are interlocked sequentially at intervals.

[0015] Furthermore, the A-type pile and the B-type pile are respectively provided with a first steel reinforcement cage and a second steel reinforcement cage.

[0016] Furthermore, the horizontal cross-section of the first reinforcing cage is rectangular.

[0017] Furthermore, the horizontal cross-section of the second reinforcing cage is circular.

[0018] Furthermore, sand piles are respectively installed on the front side of the starting piles of the interlocking piles around the foundation and the interlocking piles on the bank slope.

[0019] Furthermore, multiple acoustic detectors are respectively installed at intervals in the interlocking piles around the pier cap and the interlocking piles on the bank slope.

[0020] Furthermore, the acoustic detectors are all installed on the type B piles.

[0021] Furthermore, the cross brace has a symmetrical structure and is connected between the two opposite long sides of the crown beam.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] This utility model provides a bank slope protection foundation pit retaining structure, which is formed by interlocking steel pipe piles, interlocking pile structure, cap beam and cross bracing. After the main foundation pile foundation and bridge pier are completed, it can continue to be used as a bank slope protection structure to prevent bank collapse. It can not only prevent foundation pit collapse, but also be used as a retaining wall and cofferdam after operation. It can make good use of its own performance and avoid project waste. The interlocking steel pipe piles are used for water isolation, and the retaining structure forms a working platform. The interlocking pile structure is then constructed, which has a good waterproof effect and can adapt to construction in water environment. After the interlocking steel pipe piles are removed, one side of the interlocking pile structure is water and the other side is backfill, which can effectively balance the water and soil pressure and avoid the adverse effects of possible landslides and bank collapses. This further expands the application range of retaining structures and reduces construction difficulty and project cost. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a plan view of the present invention;

[0026] Figure 2 yes Figure 1 Sectional view of AA in the middle;

[0027] Figure 3 yes Figure 1 Cross-sectional view of the middle section (BB);

[0028] Figure 4 This is a plan view of type A piles and type B piles;

[0029] Figure 5 This is a plan view of the cap beam;

[0030] Figure 6 This is a plan view of the cross brace;

[0031] The diagram is labeled as follows:

[0032] 1-Interlocking steel pipe pile, 2-Interlocking pile structure, 21-Interlocking pile around the foundation, 22-Interlocking pile on the bank slope, 3-Cover beam, 4-Horizontal brace, 5-Type A pile, 6-Type B pile, 7-First reinforcing cage, 8-Second reinforcing cage. Detailed Implementation

[0033] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0034] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Furthermore, in the description of this utility model, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. Of course, such terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in a sequence other than those illustrated or described herein.

[0037] Example:

[0038] like Figure 1-3 As shown, this embodiment provides a bank slope protection pit retaining structure, including interlocking steel pipe piles 1, interlocking pile structure 2, cap beam 3 and cross brace 4. After the main pile foundation and bridge pier are completed, it can continue to be used as a bank slope protection structure to prevent bank collapse.

[0039] Specifically, the interlocking steel pipe pile 1 is arranged on the outer perimeter of the bank slope for water isolation. The diameter of the interlocking steel pipe pile 1 is 1m. The top of the interlocking steel pipe pile 1 is higher than the top of the cap beam 3. After the main pile foundation and bridge pier are completed, the interlocking steel pipe pile 1 can be recycled.

[0040] In this embodiment, the interlocking pile structure 2 includes a perimeter interlocking pile 21 of the foundation and a bank slope interlocking pile 22. The perimeter interlocking pile 21 of the foundation has a closed octagonal shape in plan. The side of the perimeter interlocking pile 21 of the foundation close to the locking steel pipe pile 1 and the bank slope interlocking pile 22 are both arranged parallel to the locking steel pipe pile 1. The center of the perimeter interlocking pile 21 of the foundation is 180cm away from the foundation. Both the perimeter interlocking pile 21 of the foundation and the bank slope interlocking pile 22 are reinforced concrete structures.

[0041] Among them, such as Figure 4 As shown, the interlocking piles 21 around the pier cap and the interlocking piles 22 on the bank slope both include multiple A-type piles 5 and multiple B-type piles 6. The A-type piles 5 and B-type piles 6 are interlocked sequentially. The A-type piles 5 are made of C35 underwater ultra-retarded concrete, and the retardation time of the ultra-retarded concrete should not be less than 60 hours. The B-type piles 6 are made of C35 underwater concrete, and the slump during dry hole grouting is not greater than 140 mm, and the slump during underwater grouting is not greater than 180 mm. The spacing between adjacent A-type piles 5 and B-type piles 6 is 85 cm. The diameter of A-type piles 5 and B-type piles 6 is the same, both being 1.1 m, and the interlocking length between adjacent A-type piles 5 and B-type piles 6 is 25 cm.

[0042] The A-type pile 5 has a first steel cage 7 inside. The horizontal cross section of the first steel cage 7 is rectangular, and the main reinforcement of the first steel cage 7 is HRB400φ28mm steel bar.

[0043] The B-type pile 6 has a second steel cage 8 inside. The horizontal cross section of the second steel cage 8 is circular, and the main reinforcement of the second steel cage 8 is HRB400φ25mm steel bar.

[0044] The first reinforcing cage 7 and the second reinforcing cage 8 are respectively equipped with guide pipes with an inner diameter of 200mm. After the guide pipes are lowered, the bottom of the guide pipes is 30-50cm away from the bottom. After the concrete is poured, the guide pipes are removed.

[0045] In this embodiment, the interlocking pile structure 2 is constructed using a soft cutting method. The B-type pile 6 must be constructed before the concrete of the A-type pile 5 initially sets. During the construction of the B-type pile 6, the cutting capability of the rotary drilling rig is used to cut away part of the concrete of the adjacent A-type pile 5 in order to achieve the interlocking of the A-type pile 5 and the B-type pile 6.

[0046] Among them, sand piles are set in front of the starting piles of the interlocking piles 21 around the foundation and the interlocking piles 22 on the bank slope, and water-stopping treatment is carried out at the joints of the sand piles. When continuous operation or segmented construction is not possible, the joint treatment adopts the sand pile method. Specifically, a sand pile is set at the end of the previous construction section, and the hole is filled with sand after drilling. When the subsequent construction section reaches this end, the sand is dug out and concrete is poured. After all the interlocking pile structure 2 is completed, the piles are cut off, the pile foundation is tested, and then the cap beam 3 is constructed.

[0047] Multiple acoustic detectors are installed at intervals in the interlocking piles 21 around the foundation and the interlocking piles 22 on the bank slope. In this embodiment, the acoustic detectors are acoustic logging tubes, and a detection point is set every 6m. The acoustic detectors are all installed on the B-type piles 6. The acoustic logging tubes are installed at the same time during the process of installing the first steel cage 7 and the second steel cage 8. The acoustic logging tubes are made of φ57×3mm steel pipes.

[0048] In this embodiment, as Figure 5 As shown, the cap beam 3 is set on top of the interlocking piles 21 around the foundation. The cap beam 3 is a reinforced concrete structure. The cap beam 3 has an octagonal plane and a rectangular cross section of 1.5m (width) × 1m (height) in the longitudinal direction. The steel reinforcement skeleton of the interlocking piles 21 around the foundation extends into the cap beam 3.

[0049] like Figure 6 As shown, the cross brace 4 is located in the middle of the cap beam 3. The cross brace 4 is a symmetrical reinforced concrete structure that connects the two opposite long sides of the cap beam 3. In this embodiment, the concrete grade of both the cap beam 3 and the cross brace 4 is C40. In other embodiments, the permanent concrete cross brace 4 can also be replaced with a temporary steel pipe support structure, which can enhance the convenience of construction.

[0050] To ensure the accuracy of the borehole of the interlocking pile structure 2 and improve the positioning efficiency, a concrete guide wall is set on the top of the interlocking pile structure 2. The guide wall is 500mm thick, 1000mm wide on one side, and the top of the guide wall is 100mm above the ground. A continuous steel mesh of Φ12@200mm is installed on the top of the guide wall. The concrete grade of the guide wall is C20. After the construction of the interlocking pile structure 2 is completed, the guide wall is removed.

[0051] To prevent the effective pile length of the interlocking pile structure 2 from falling due to concrete falling, the sleeve and guide pipe are pulled out 2-3m beyond the designed pile top when the concrete is poured to near the pile top elevation. Concrete is then poured using a hopper until fresh concrete emerges. After pouring, the guide pipe and sleeve are removed.

[0052] The retaining structure in this embodiment can not only prevent the foundation pit from collapsing, but also be used as a retaining wall and cofferdam after operation. It can make good use of its own performance and will not cause engineering waste. Furthermore, the use of interlocking steel pipe piles 1 to form a working platform after the retaining structure is enclosed, and then the interlocking pile structure 2 is constructed, which makes the waterproof effect good and can adapt to construction in watery environments.

[0053] In this embodiment, each structure has a clear function, a clear force transmission path, and is easy to construct. The interlocking piles 21 around the foundation form a closed polygonal plane. After the locking steel pipe piles 1 are removed, one side of the interlocking pile structure 2 is water and the other side is backfill, which can effectively balance the water and soil pressure and avoid the interlocking pile structure 2 from being affected by possible landslides, bank collapses, etc., further expanding the application scope of the retaining structure and reducing the construction difficulty and project cost.

[0054] The construction process for interlocking pile structure 2 is as follows:

[0055] Impact drilling pilot hole - filling the hole with sand and gravel - constructing guide wall - inserting the full casing of type A pile 5 - hoisting the first steel cage 7 - inserting the guide pipe - pouring super slow-setting concrete - inserting the full casing of type B pile 6 - hoisting the second steel cage 8 - inserting the guide pipe - pouring concrete - cycle.

[0056] The construction steps for Type A pile 5 are as follows:

[0057] Full casing drilling, rotary drilling for soil removal - final hole acceptance - installation of the first reinforcing cage 7 - installation of the guide pipe - pouring of super slow-setting concrete (guide pipe buried at a depth of 3-6m) - lifting the casing and guide pipe 2.5m above the pile top (using a hopper to continue pouring until fresh concrete is exposed) - removal of the guide pipe and casing.

[0058] The construction steps for type B pile 6 are as follows:

[0059] Full casing drilling, rotary drilling for soil removal - final hole acceptance - installation of the second reinforcing cage - installation of the guide pipe - concrete pouring (guide pipe buried at a depth of 3-6m) - lifting the casing and guide pipe 2.5m above the pile top (using a hopper to continue pouring until fresh concrete is exposed) - removal of the guide pipe and casing.

[0060] The construction steps in this embodiment are as follows:

[0061] During construction, the interlocking steel pipe piles 1 are driven and the island is built first. After the island is built, the water-retaining embankment is constructed. Then, the interlocking pile structure 2 and the main pier pile foundation are constructed. After the main pier pile foundation is completed, the cap beam 3 and the cross brace 4 are constructed. Then, the foundation pit of the pier is excavated. When the excavation reaches 1.5m from the bottom of the cap beam 3, the debris at the bottom of the cap beam 3 is cleaned up. Then, the excavation continues to the bottom of the cushion layer. Finally, the main pier foundation is constructed.

[0062] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A slope protection foundation pit retaining structure, characterized in that: It includes interlocking steel pipe piles (1), interlocking pile structure (2), cap beam (3) and cross bracing (4); The locking steel pipe piles (1) are arranged on the outer perimeter of the bank slope; The interlocking pile structure (2) includes a perimeter interlocking pile (21) of the pier cap and a side interlocking pile (22) of the bank slope. The perimeter interlocking pile (21) of the pier cap and the side interlocking pile (22) of the bank slope are both arranged parallel to the lock steel pipe pile (1). Both the perimeter interlocking pile (21) of the pier cap and the side interlocking pile (22) of the bank slope are reinforced concrete structures. The crown beam (3) is located on the top of the interlocking piles (21) around the foundation, and the cross brace (4) is located in the middle of the crown beam (3).

2. The slope protection foundation pit retaining structure according to claim 1, characterized in that: The top of the locking steel pipe pile (1) is higher than the top of the cap beam (3).

3. The slope protection foundation pit retaining structure according to claim 1, characterized in that: The interlocking piles (21) around the pier and the interlocking piles (22) on the bank slope each include multiple type A piles (5) and multiple type B piles (6), and the type A piles (5) and the type B piles (6) are interlocked in sequence at intervals.

4. The slope protection foundation pit retaining structure according to claim 3, characterized in that: The A-type pile (5) and the B-type pile (6) are respectively provided with a first steel cage (7) and a second steel cage (8).

5. The slope protection foundation pit retaining structure according to claim 4, characterized in that: The horizontal cross-section of the first steel cage (7) is rectangular.

6. The slope protection foundation pit retaining structure according to claim 4, characterized in that: The horizontal cross-section of the second steel cage (8) is circular.

7. The slope protection foundation pit retaining structure according to claim 1, characterized in that: Sand piles are respectively installed on the front side of the starting piles of the perimeter interlocking piles (21) of the foundation and the side interlocking piles (22) of the bank slope.

8. The slope protection foundation pit retaining structure according to claim 1, characterized in that: Multiple acoustic detectors are respectively installed at intervals in the interlocking piles (21) around the foundation and the interlocking piles (22) on the bank slope.

9. The slope protection foundation pit retaining structure according to claim 8, characterized in that: The acoustic detectors are all installed on the B-type pile (6).

10. The slope protection foundation pit retaining structure according to claim 1, characterized in that: The cross brace (4) is a symmetrical structure and is connected between the two opposite long sides of the crown beam (3).

Images