Construction method of prefabricated assembled retaining wall with artificial bored piles

Abstract

The present invention discloses a construction method for a prefabricated and assembled retaining wall for bored piles, comprising: ① first ring installation: excavating a circular trench on the ground according to the designed position, then placing the first and second prefabricated blocks so that they are alternately arranged to form a ring; then, installing a steel shoulder pole on the embedded screw at the top of the first prefabricated block, and providing square wood pads at both ends of the steel shoulder pole, so that the first prefabricated block is tightly connected to the second prefabricated block by tightening it; ② second ring installation: continuing to excavate the soil downward, when the predetermined depth is reached, first installing the second prefabricated block and connecting it to the first prefabricated block on the upper layer via embedded components; then, inserting the first prefabricated block from bottom to top between adjacent second prefabricated blocks, and connecting it to the second prefabricated block on the upper layer via embedded components; finally, sealing the operating hole with quick-drying cement; and ③ repeating the second step until the entire retaining wall construction is completed. The present invention improves the construction quality of retaining wall concrete and reduces the safety risk of bored pile hole wall collapse.

Description

Technical Field

[0001] The invention relates to the technical field of artificial bored pile construction, in particular to a construction method for a prefabricated assembled retaining wall of an artificial bored pile. Background Art

[0002] Manual bored pile construction is convenient, fast, and does not require large-scale machinery. Bored piles are more earthquake-resistant than wooden piles and driven concrete piles, and are less expensive than punching with a punch cone, impact cone, impact drill, rotary drill, or caisson foundations. Therefore, they are widely used in roads and civil construction. To prevent collapse and ensure operational safety, a cast-in-place reinforced concrete retaining wall can be constructed while the earth is excavated. After the formwork is supported, a casting gap must be reserved, usually in the form of a thick-top-thin-bottom inclined step. The above-mentioned cast-in-place retaining wall technology has a slow construction speed, is difficult to control quality, and requires a high amount of mixed soil. Secondly, when constructing in areas with quicksand geology, construction is usually impossible because the formwork cannot be quickly closed into a ring. Thirdly, when constructing bored piles near existing railway lines, the vibration caused by driving vehicles can cause cracks in the cast-in-place concrete retaining wall, affecting the stability of the retaining wall and causing safety accidents. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a construction method of prefabricated assembled retaining wall of artificial bored piles, which can specifically adopt the following technical solutions:

[0004] The construction method of the prefabricated assembled retaining wall of the artificial bored pile described in the present invention comprises the following steps:

[0005] The guard wall is a cylindrical structure assembled by a first prefabricated block and a second prefabricated block, the first prefabricated block and the second prefabricated block are arranged in multiple layers from top to bottom, the first prefabricated blocks and the second prefabricated blocks in the same layer are staggered and connected with inclined surfaces, and the first prefabricated blocks and the second prefabricated blocks in adjacent layers are connected and fixed by embedded components; the orthographic projection of the first prefabricated block on the side wall of the pile hole is an upright isosceles trapezoid, and the orthographic projection of the second prefabricated block on the side wall of the pile hole is an inverted isosceles trapezoid, and the upper base of the upright isosceles trapezoid is shorter than the lower base of the inverted isosceles trapezoid, and the lower base of the upright isosceles trapezoid is shorter than the upper base of the inverted isosceles trapezoid; the embedded component includes an embedded screw and an embedded sleeve adapted therewith, the embedded screw is arranged on the top of the first prefabricated block and the second prefabricated block and extends upward, the embedded sleeve is arranged at the bottom of the first prefabricated block and the second prefabricated block, and an operating hole is provided above the embedded sleeves of the first prefabricated block and the second prefabricated block;

[0006] The construction method comprises the following steps:

[0007] The first step is to install the first ring: according to the designed location of the bored pile, a circular trench with the same diameter as the retaining wall is excavated on the ground. Then, the first and second prefabricated blocks are placed, alternating to form a ring. Next, a steel shoulder pole is installed on the embedded screw rod at the top of the first prefabricated block, and square wood pads are placed at both ends of the steel shoulder pole. By tightening the first prefabricated block, it is tightly connected to the second prefabricated block.

[0008] The second step is to install the second ring layer: continue to excavate the soil downwards. When the predetermined depth is reached, first install the second prefabricated block and connect it to the first prefabricated block on the upper layer through embedded components. Then, insert the first prefabricated block from bottom to top between the adjacent second prefabricated blocks and connect it to the second prefabricated block on the upper layer through embedded components. Finally, seal the operation hole with quick-drying cement.

[0009] The third step is to repeat the second step until the construction of the entire retaining wall is completed.

[0010] The first and second prefabricated blocks are both provided with L-shaped reinforcing ribs around the embedded screws and embedded sleeves, which can improve the connection firmness between the embedded screws and embedded sleeves and the prefabricated blocks.

[0011] The outer sides of the first and second prefabricated blocks are both roughened, and waterstops are provided on the joint surfaces of the first and second prefabricated blocks. The roughened surfaces help strengthen the connection between the prefabricated blocks and the soil, and the waterstops (such as waterstop strips) effectively stop water from flowing through the retaining wall.

[0012] The weight of the first prefabricated blocks and the second prefabricated blocks are both less than 90 kg, and the number of the first prefabricated blocks and the second prefabricated blocks in the same layer is equal.

[0013] Preferably, when the outer diameter of the retaining wall is ≤1.5m, the sum of the number of the first prefabricated blocks and the second prefabricated blocks on the same layer is 8; when the outer diameter of the retaining wall is between 1.5-2m, the sum of the number of the first prefabricated blocks and the second prefabricated blocks on the same layer is 12.

[0014] Preferably, when the bored pile depth is less than 10 meters, the wall thickness of the retaining wall is 100 mm; when the bored pile depth is greater than or equal to 10 meters, the wall thickness of the retaining wall is 120 mm.

[0015] Preferably, in the second step, when installing the first prefabricated block and the second prefabricated block, a 4-6 cm thick M10 mortar layer is applied between them and the side wall of the pile hole; before sealing the operation hole, the connection structure of the embedded component is tightened again so that the first prefabricated block and the second prefabricated block on the same layer are tightly connected.

[0016] The present invention adopts trapezoidal prefabricated blocks of two specifications to be spliced ​​into a ring, and is arranged layer by layer. The two trapezoidal prefabricated blocks on the same layer are staggered and connected, and support each other under the action of the inclined trapezoidal socket surface. The adjacent rings are fastened into a whole by interlayer embedded connectors. The construction is fast, the structure is stable, and it can be quickly closed into a ring when digging holes. It improves the construction speed and reduces the amount of concrete used in the manual bored pile wall by combining factory prefabrication and on-site assembly, effectively saving construction costs, improving the construction quality of the wall concrete, and reducing the safety risk of bored pile hole wall collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the protective wall in the present invention.

[0018] Figure 2 yes Figure 1 Schematic diagram of the projection structure of the first prefabricated block.

[0019] Figure 3 yes Figure 1 Schematic diagram of the projection structure of the second prefabricated block.

[0020] Figure 4a-4d It is a schematic diagram of the installation of the retaining wall in the present invention. DETAILED DESCRIPTION

[0021] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and a specific construction process are given. However, the protection scope of the present invention is not limited to the following embodiment.

[0022] like Figure 1-3 As shown, the construction method of the prefabricated, assembled bored pile retaining wall described in the present invention is targeted at a cylindrical retaining wall structure assembled from first and second prefabricated blocks 1, 2. The first and second prefabricated blocks 1, 2 are arranged in multiple layers from top to bottom. The first and second prefabricated blocks 1, 2 on the same layer are staggered and joined at an inclined surface. The first and second prefabricated blocks 1, 2 on adjacent layers are connected and secured via embedded components. Typically, the number of first and second prefabricated blocks 1, 2 on a given layer is equal.

[0023] Specifically, the pile hole diameter in this embodiment is 1.5m, and each layer is composed of four first prefabricated blocks 1 and four second prefabricated blocks 2. The orthographic projection of the first prefabricated block 1 on the side wall of the pile hole is an upright isosceles trapezoid (see Figure 2 ), the orthographic projection of the second prefabricated block 2 on the side wall of the pile hole is an inverted isosceles trapezoid (see Figure 3), and the upper base of the upright isosceles trapezoid is shorter than the lower base of the inverted isosceles trapezoid, and the lower base of the upright isosceles trapezoid is shorter than the upper base of the inverted isosceles trapezoid. That is, the first prefabricated block 1 and the second prefabricated block 2 are isosceles trapezoids of equal height, with an inclined figure-eight joint surface. However, the first prefabricated block 1 is smaller than the second prefabricated block 2. With this isosceles trapezoidal structure, when the first prefabricated block 1 is lifted, the inclined contact surface strengthens its interaction with the second prefabricated block 2, ensuring a tight and seamless annular structure.

[0024] The embedded components for connecting the first prefabricated block 1 and the second prefabricated block 2 include an embedded screw 3 and an embedded sleeve 4 adapted thereto. Specifically, the embedded screw 3 is located at the center of the top of the first prefabricated block 1 and the second prefabricated block 2 and extends upward by about 15 cm. The embedded sleeve 4 is located at the bottom of the first prefabricated block 1 and the second prefabricated block 2, and an operating hole 5 is provided above the embedded sleeve 4 of the first prefabricated block 1 and the second prefabricated block 2. When the first prefabricated block 1 and the second prefabricated block 2 are stacked and assembled, the embedded screw 3 is passed through the embedded sleeve 4 of the upper layer, and the fastening nut 6 is screwed onto the embedded bolt 3 through the operating hole 5 to connect the two prefabricated blocks together. After the construction is completed, the operating hole 5 is sealed with quick-drying cement. In order to facilitate the positioning of the embedded screw 3 and the embedded sleeve 4 and improve the connection strength between them and the first prefabricated block 1 and the second prefabricated block 2, L-shaped reinforcement ribs 7 are provided around the embedded screw 3 and the embedded sleeve 4 in the first prefabricated block 1 and the second prefabricated block 2.

[0025] To strengthen the connection between the first and second prefabricated blocks 1 and 2 and the soil, the exterior surfaces of the first and second prefabricated blocks 1 and 2 are roughened. Furthermore, waterstops (such as waterstop strips) are installed on the joint surfaces of the first and second prefabricated blocks 1 and 2, ensuring effective watertightness even in areas with abundant groundwater. Furthermore, to facilitate construction, the weight of the first and second prefabricated blocks 1 and 2 is less than 90 kg.

[0026] The construction method of the prefabricated assembled retaining wall of the manually bored piles of the present invention comprises the following steps:

[0027] The first step is to install the first ring: according to the designed position of the bored pile, a circular groove with the same diameter as the retaining wall is excavated on the ground. Then, the first prefabricated block 1 and the second prefabricated block 2 are placed, and the two are arranged alternately to form a ring. Then, a steel shoulder pole 8 is installed on the embedded screw 3 on the top of each first prefabricated block 1, and square wood 9 is placed on the ground at both ends of the steel shoulder pole 8 (see Figure 4a ), to prevent the prefabricated blocks from sinking. Under the action of the steel shoulder pole 8, the first prefabricated block 1 is pulled upward, and its two side inclined surfaces contact the second prefabricated block 2, so that a certain circumferential thrust is generated between the first prefabricated block 1 and the second prefabricated block 2, thereby tightly connecting the first ring.

[0028] Specifically, the first and second prefabricated blocks 1 and 2 are arranged alternately to form a ring. When the first prefabricated block 1 is tightened upward to the steel shoulder pole 8 via the embedded screw 3 and the fastening nut 6, the first prefabricated block 1 contacts the second prefabricated block 2, generating a certain upward thrust that drives the second prefabricated blocks 2 on both sides upward, while the upper steel shoulder pole 8 generates a downward thrust that prevents the second prefabricated blocks 2 from moving upward. Because the top surfaces of the first and second prefabricated blocks 1 and 2 are both curved, with the arc being wide on the outside and narrow on the inside, the first prefabricated block 1 can convert the restraining force into an interblock annular thrust when tightened. When the ring-shaped first and second prefabricated blocks 1 and 2 are squeezed by passive earth pressure, similar to the force acting on an arch bridge, the first and second prefabricated blocks 1 and 2 can convert the squeezed passive earth pressure into an interblock annular thrust to resist the earth pressure.

[0029] Step 2: Installation of the second ring: Continue to dig the soil downwards. When the predetermined depth is reached, first install the second prefabricated block 2 (see Figure 4b ), then install the first prefabricated block 1 (see Figure 4c 、 Figure 4d ), and finally block the operation hole 5.

[0030] Specifically, the second prefabricated block 2 is installed below the upper first prefabricated block 1. The two are connected via an embedded assembly. Specifically, the embedded screw 3 at the top of the second prefabricated block 2 is inserted into the embedded sleeve 4 of the first prefabricated block 1 above it. A fastening nut 6 is screwed onto the embedded bolt 3 through the operating hole 5 to connect the two prefabricated blocks. Then, a 4-6 cm thick layer of M10 mortar is applied to the outside of the second prefabricated block 2 or the sidewall of the pile hole to ensure a tight connection between the two. Next, the first prefabricated block 1 is inserted from bottom to top into the gap between the adjacent second prefabricated blocks 2. This is connected to the upper second prefabricated block 2 via the embedded assembly. Finally, a 4-6 cm thick layer of M10 mortar is applied to the outside of the first prefabricated block 1 or the sidewall of the pile hole. Finally, each fastening nut 6 is re-tightened to ensure the prefabricated blocks are firmly connected, and the operating hole 5 is sealed with quick-drying cement. During the installation process, the first prefabricated block 1 can generate continuous circumferential thrust under the pressure of the second prefabricated block 2 on the upper layer and the force of the oblique contact surface between the first prefabricated block 1 and the second prefabricated block 2 on the same layer, so that the second layer ring is tightly connected together.

[0031] The third step is to repeat the second step until the construction of the entire retaining wall is completed.

[0032] Generally, when the bored pile depth is less than 10 meters, the wall thickness of the retaining wall is 100 mm; when the bored pile depth is greater than or equal to 10 meters, the wall thickness of the retaining wall is 120 mm.

[0033] Compared with the prior art, the advantages of the present invention are mainly:

[0034] Firstly, the existing difficulties of slow construction speed and difficult quality control of cast-in-place retaining walls of bored piles are solved. The prefabricated assembled retaining wall of the present invention can be quickly closed into a ring when the hole is dug, which reduces the time for waiting for the cast-in-place retaining wall to harden and speeds up the construction speed.

[0035] Secondly, the existing cast-in-place retaining wall needs to reserve a casting gap after the formwork is supported, and the thickness of the cast retaining wall varies. The thickness of the upper retaining wall is 15 cm, while the thickness of the lower retaining wall is only 5-8 cm. The prefabricated assembled retaining wall described in the present invention has a uniform thickness, wherein the thickness of the prefabricated blocks is 6 cm. After the assembly is completed, 4-6 cm thick M10 mortar is set on the outside of the retaining wall. Therefore, the thickness of the retaining wall after molding is 10-12 cm. It does not require in-hole casting, which can reduce the thickness of the retaining wall, save construction costs, and save the amount of retaining wall concrete.

[0036] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships such as “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “inside”, and “outside” are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Claims

1. A construction method for prefabricated and assembled retaining wall of manually excavated piles, characterized by: The guard wall is a cylindrical structure assembled by a first prefabricated block and a second prefabricated block, the first prefabricated block and the second prefabricated block are arranged in multiple layers from top to bottom, the first prefabricated blocks and the second prefabricated blocks in the same layer are staggered and connected with inclined surfaces, and the first prefabricated blocks and the second prefabricated blocks in adjacent layers are connected and fixed by embedded components; the orthographic projection of the first prefabricated block on the side wall of the pile hole is an upright isosceles trapezoid, and the orthographic projection of the second prefabricated block on the side wall of the pile hole is an inverted isosceles trapezoid, and the upper base of the upright isosceles trapezoid is shorter than the lower base of the inverted isosceles trapezoid, and the lower base of the upright isosceles trapezoid is shorter than the upper base of the inverted isosceles trapezoid; the embedded component includes an embedded screw and an embedded sleeve adapted therewith, the embedded screw is arranged on the top of the first prefabricated block and the second prefabricated block and extends upward, the embedded sleeve is arranged at the bottom of the first prefabricated block and the second prefabricated block, and an operating hole is provided above the embedded sleeves of the first prefabricated block and the second prefabricated block; The construction method comprises the following steps: The first step is to install the first ring: according to the designed location of the bored pile, a circular trench with the same diameter as the retaining wall is excavated on the ground. Then, the first and second prefabricated blocks are placed, alternating to form a ring. Next, a steel shoulder pole is installed on the embedded screw rod at the top of the first prefabricated block, and square wood pads are placed at both ends of the steel shoulder pole. By tightening the first prefabricated block, it is tightly connected to the second prefabricated block. The second step is to install the second ring layer: continue to excavate the soil downwards. When the predetermined depth is reached, first install the second prefabricated block and connect it to the first prefabricated block on the upper layer through embedded components. Then, insert the first prefabricated block from bottom to top between the adjacent second prefabricated blocks and connect it to the second prefabricated block on the upper layer through embedded components. Finally, seal the operation hole with quick-drying cement. The third step is to repeat the second step until the construction of the entire retaining wall is completed.

2. The construction method of the prefabricated assembled retaining wall of manually excavated piles according to claim 1 is characterized by: The first prefabricated block and the second prefabricated block are both provided with L-shaped reinforcing ribs around the embedded screw and the embedded sleeve.

3. The construction method of the prefabricated assembled retaining wall of manually excavated piles according to claim 1 is characterized by: The outer side surfaces of the first prefabricated block and the second prefabricated block are both roughened surfaces, and water stoppers are provided on the joint surfaces of the first prefabricated block and the second prefabricated block.

4. The construction method of the prefabricated assembled retaining wall of manually excavated piles according to claim 1 is characterized by: The weight of the first prefabricated blocks and the second prefabricated blocks are both less than 90 kg, and the number of the first prefabricated blocks and the second prefabricated blocks in the same layer is equal.

5. The construction method of the prefabricated assembled retaining wall of manually bored piles according to claim 4 is characterized by: When the outer diameter of the retaining wall is ≤1.5m, the sum of the number of the first prefabricated blocks and the second prefabricated blocks on the same layer is 8; when the outer diameter of the retaining wall is between 1.5-2m, the sum of the number of the first prefabricated blocks and the second prefabricated blocks on the same layer is 12.

6. The construction method of the prefabricated assembled retaining wall of manually bored piles according to claim 1 is characterized by: When the bored pile depth is less than 10 meters, the wall thickness of the retaining wall is 100 mm; when the bored pile depth is greater than or equal to 10 meters, the wall thickness of the retaining wall is 120 mm.

7. The construction method of prefabricated and assembled retaining wall of manually bored piles according to claim 1 is characterized by: In the second step, when installing the first prefabricated block and the second prefabricated block, a 4-6 cm thick M10 mortar layer is applied between the first prefabricated block and the side wall of the pile hole; before sealing the operation hole, the connection structure of the embedded component is tightened again so that the first prefabricated block and the second prefabricated block on the same layer are tightly connected.

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