Patent ID: 12188198

REFERENCE NUMERALS

1. pile foundation body;11. steel reinforcement ring;12. side connecting reinforcement bar;13. central vertical reinforcement bar;14. spiral reinforcement tube;15. measuring nail;16. bottom wooden board; and17. side wooden board; and2. extension body.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to make the objectives, technical solutions, and advantages of embodiments of the present disclosure clearer, the following clearly and completely describes the technical solutions in the embodiments of the present disclosure with reference to the embodiments of the present disclosure. Apparently, the described embodiments are some rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts should fall within the protection scope of the present disclosure.

Embodiment 1

As shown inFIGS.1,2, and3, a method for constructing a fixed monitoring pile for a mining area with a high phreatic water level includes the following steps.

S1. Pile foundation body1is prefabricated. The pile foundation body1has a columnar structure, and a plurality of extension connection ports are provided at an outer side and a bottom of the pile foundation body1.

The pile foundation body1includes the following components that are combined together through cement pouring: a plurality of steel reinforcement rings11, a plurality of side connecting reinforcement bars12, central vertical reinforcement bar13, and a plurality of spiral reinforcement tubes14.

In this embodiment, there are three steel reinforcement rings11. The three steel reinforcement rings11are regular polygons with four or more sides. This embodiment illustrates quadrilateral steel reinforcement rings. The sizes of the three steel reinforcement rings11increase in order from top to bottom, with the largest steel reinforcement ring11located at a bottom of a foundation pit. The three steel reinforcement rings11are vertically spaced and connected by the plurality of side connecting reinforcement bars12. The central vertical reinforcement bar13is located at a center of the steel reinforcement ring11. The plurality of spiral reinforcement tubes14are distributed at the outer side of the pile foundation body1, and open ends of the spiral reinforcement tubes14form the extension connection ports.

In this embodiment, a specific production process of the pile foundation body1is as follows.

S11. The plurality of steel reinforcement rings11, the plurality of side connecting reinforcement bars12, the central vertical reinforcement bar13, the plurality of spiral reinforcement tubes14, measuring nail15, bottom wooden board16, and side wooden boards17are prefabricated.

The steel reinforcement rings11of three specifications each can be formed by bending and connecting an entire reinforcement bar or by welding a plurality of reinforcement bars. The dimensions of top steel reinforcement ring11′ are: La=0.36 m, and φ=20 mm, and the dimensions of middle steel reinforcement ring11′ are: Lb=0.41 m, and φ=20 mm. The dimensions of bottom steel reinforcement ring11′″ are: Lc=0.56 m, and φ=20 mm. The dimensions of the side connecting reinforcement bar12are: L=1.0 m, and φ=20 mm. The dimension of the spiral reinforcement tube14is L=0.05 m, and the spiral reinforcement tube is provided therein with a spiral opening. A side number of the steel reinforcement ring11is equal to a side number of the side connecting reinforcement bar12.

The dimensions of the central vertical reinforcement bar13are: L=1.0 m, and φ=20 mm. An upper part of measuring nail15is provided with a cross nut, φ=20 mm. The measuring nail is connected to a top of the central vertical reinforcement bar13. A bottom of the central vertical reinforcement bar13is connected to a spiral reinforcement tube14. More specifically, the top of the central vertical reinforcement bar13is welded to the measuring nail15, and the bottom thereof is welded to a vertical spiral reinforcement tube14. A total length of a combination of the central vertical reinforcement bar13, the top measuring nail15, and the bottom spiral reinforcement tube14is greater than a length of the pile foundation body1, and the top measuring nail15is precisely located at a top protruding position of the pile foundation body1.

The bottom wooden board16is a polygon and is compatible with the bottom steel reinforcement ring11″. The dimensions of the bottom wooden board16are: L (side)=0.6 m, and φ(hole)=20 mm. The side wooden board17is a trapezoidal board. Therefore, the dimensions of the side wooden board17are: L (long base)=0.6 m, L (short base)=0.4 m, and φ(hole)=20 mm. The long base of the side wooden board17is 4 cm longer than the side of the bottom steel reinforcement ring11″, and the short base of the side wooden board17is 4 cm longer than the side of the top steel reinforcement ring11″.

The side wooden board17is provided with two holes corresponding to the lateral spiral reinforcement tube14, and a diameter of the holes is equal to a diameter of the lateral spiral reinforcement tube14. The bottom wooden board16is provided with a hole corresponding to the vertical spiral reinforcement tube14at the bottom of the central vertical reinforcement bar13. The hole of the bottom wooden board16is located at a center of the regular polygon, and has a diameter equal to a diameter of the vertical spiral reinforcement tube14.

The length of the long base of the side wooden board17is equal to the side length of the bottom wooden board16, and the number of the side wooden boards17is equal to the side number of the bottom wooden board16.

S12. The plurality of steel reinforcement rings11are connected to the plurality of side connecting reinforcement bars12to form a cage structure. The spiral reinforcement tube14is connected at a connection between the steel reinforcement ring11and the side connecting reinforcement bar12. The bottom wooden board16is provided at a bottom of the cage structure, and the side wooden boards17are sequentially connected at sides of the cage structure.

Specifically, the side connecting reinforcement bar12is inclined, and the side connecting reinforcement bar12is at a 75-90° angle, preferably an 85° angle, to a horizontal plane. After the side connecting reinforcement bar12is inclined, the lateral spiral reinforcement tubes14are welded horizontally to the middle and bottom of the side connecting reinforcement bars12. In this embodiment, the side connecting reinforcement bar12is 1.0 m long. The spiral reinforcement tubes14are respectively welded at a fixed position that is 0.05 m far from the bottom of the side connecting reinforcement bar12and a position that is 0.1 m far from the middle of the side connecting reinforcement bar.

The bottom steel reinforcement ring11′″ is tied to the spiral reinforcement tube14at the 0.05 m fixed position with an iron wire or other tying wires. The bottom steel reinforcement ring11′″ is located above the spiral reinforcement tube14. The position where the bottom steel reinforcement ring11′″ is tied is in the middle of each side.

The central steel reinforcement ring11″ is tied to the spiral reinforcement tube14at the 0.1 middle position with an iron wire or other tying wires. The central steel reinforcement ring11″ is located above the spiral reinforcement tube14. The position where the bottom steel reinforcement ring11′″ is tied is in the middle of each side.

The top steel reinforcement ring11′ is tied to the top of the side connecting reinforcement bar12with an iron wire or other tying wires. The position where the top steel reinforcement ring11′ is tied is in the middle of each side.

S13. The top of the central vertical reinforcement bar is connected to the measuring nail15, and the bottom of the central vertical reinforcement bar is connected to the spiral reinforcement tube to form a combination, and the combination is connected to the center of the bottom wooden board16.

Specifically, on a site where the pile foundation body1is prefabricated, the bottom wooden board16is placed in order, and a combination of the central vertical reinforcement bar13, the measuring nail15, and the vertical spiral reinforcement tube14is placed on the bottom wooden board16. The vertical spiral reinforcement tube14is placed on the bottom wooden board16and corresponds to the hole of the bottom wooden board16. A combination of the side connecting reinforcement bars12, the three steel reinforcement rings11, and the lateral spiral reinforcement tubes14, as well as the side wooden board17, are placed in order on the sides of the bottom wooden board. The lateral spiral reinforcement tubes14are placed on inner sides of the side wooden board17and correspond to the holes of the side wooden board17. The side wooden board17is tied in fixed order, and the bottom of the side wooden board17is combined with the side boundaries of the bottom wooden board16.

S14. Cement mortar is poured inside the bottom wooden board16and the side wooden boards17. After the cement mortar solidifies, the bottom wooden board16and the side wooden boards17are removed.

Specifically, the cement mortar includes a combination of cement, yellow sand, and gravel that are mixed in a ratio of 1:2:2 and are stirred into a fluid by water.

After the cement mortar inside the prefabricated wooden template solidifies, the side wooden boards17and the bottom wooden board16are removed to form the pile foundation body1.

In this embodiment, the pile foundation body1is 1 m high, with a top side length of 0.36 m and a bottom side length of 0.6 m.

S2. The foundation pit is dug at a designated monitoring point. The pile foundation body1is combined with extension body2to form a fixed monitoring pile. The fixed monitoring pile is placed into the foundation pit, and bottom extension body2′ and side extension body2′ are inserted into the pit foundation. Then backfilling and compaction operations are conducted.

The bottom extension body2′ and the side extension body2′ are threaded and are connected in a threaded manner to the bottom vertical spiral reinforcement tube14and the lateral spiral reinforcement tube14.

In this embodiment, the dimensions of the side extension body2″ are: L=0.45 m, and φ=20 mm, and one side of the side extension is threaded. The dimensions of the bottom extension body2′ are: L=0.5 m, and φ=20 mm, and a top of the bottom extension is threaded.

In this embodiment, the extension body2is a straight rod made of a reinforcement bar. Of course, the extension body2can also be curved, such as wavy and hooked, to further improve the bonding strength between the extension body and soil.

At the designated monitoring point, known fixed points (undisturbed points) are found at upper and lower positions of a working face in a mining area according to drawings. Observation lines are set up along the strike and inclination of the working face, and the fixed points are set up along the observation lines. At the undisturbed points, a disturbance range of the working face is calculated using a probability integration method before mining. The undisturbed points should be located outside the disturbance range, and the plurality of fixed points should be set up outside each disturbance range to prevent human influence.

A distance between designated monitoring points is appropriately 45 m, and the monitoring points should be densified at the mining boundary of the working face. In addition, they should avoid unsuitable locations such as ponds and temporary spoil banks.

A pit foundation with corresponding depth and width (H=1 m, L (bottom)=1.4 m) is dug according to the size of a steel reinforcement mold.

The pile foundation body1is hoisted through a crane or other means. The bottom extension body2′ is rotated into the vertical spiral reinforcement tube14, while the side extension body2′ is rotated into the lateral spiral reinforcement tube14.

The prefabricated fixed monitoring pile is transported to the designated monitoring point using a crane, and trucks and cranes can be used along the way.

The fixed monitoring pile is placed into the foundation pit through a crane or other means. The side extension body2′ is placed according to the opening of the foundation pit, and an exposed section of the bottom extension body2′ fully extends into a loose layer. The original soil is backfilled outside the fixed monitoring pile. The soil outside the monitoring pile is compacted by stones, and water is sprinkled to the upper part of the soil, allowing water to seep into the bottom of the soil to make it compact. Then the upper part of the compacted soil is further covered with soil, and the soil is compacted.

In this embodiment, a plurality of extension connection ports are formed on the sides of the pile foundation body1and the ground. The extension connection ports are detachably connected to the plurality of extension bodies2, forming an externally radiated fixed monitoring pile. On the one hand, the pile foundation body1and the extension body2are transported separately and assembled in the proximity of the foundation pit or a pre-assembly point to avoid transporting the entire fixed monitoring pile with a large volume, which is convenient for transportation and avoids additional transportation costs and difficulties. On the other hand, after the fixed monitoring pile is buried in the pit foundation, the side extension body2and the bottom extension body2′ extend out of the pile foundation body1and enter the loose layer, increasing the contact area between the fixed monitoring pile and the loose layer. The design increases the affinity between fixed monitoring pile and the loose layer, and strengthens the fixed monitoring pile to prevent it from loosening, thereby improving measurement accuracy.

Embodiment 2

As shown inFIG.7, this embodiment differs from Embodiment 1 in the side number of the steel reinforcement ring11.

In this embodiment, three steel reinforcement rings11each include six sides. In addition, the fixed monitoring pile includes side connecting reinforcement bars12, twelve lateral spiral reinforcement tubes14, six side wooden boards17, and twelve extension bodies2′ located on the sides of side extension body2. This embodiment increases the side number of the steel reinforcement ring11, and adaptively increases the number of the side extension bodies2′, improving the bonding force between the fixed monitoring pile and the soil.

The foregoing embodiments are only used to explain the technical solutions of the present disclosure, and are not intended to limit the same. Although the present disclosure is described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent substitutions on some technical features therein. These modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.