Connecting beam type pile net composite foundation structure

Abstract

The utility model discloses a coupling beam type pile net composite foundation structure which comprises a coupling beam, a reinforced mattress layer and a plurality of foundation reinforcing piles, the foundation reinforcing piles are arranged in a square mode, the tops of the foundation reinforcing piles are in longitudinal and transverse rigid connection through the coupling beam, haunch angles are arranged at cross joints of the coupling beam, a plain concrete cushion layer is arranged at the bottom of the coupling beam, and the reinforced mattress layer is arranged at the top of the coupling beam. And the reinforced mattress layer is formed by paving a layer of geotextile material in a broken stone hardcore. According to the coupling beam type pile net composite foundation technology, a pile cap structure is replaced by longitudinal and transverse crossed coupling beams, the pile-soil stress ratio is effectively increased, the foundation settlement control effect is further enhanced, and compared with a traditional piled raft or pile plate structure, a large amount of engineering investment can be saved while the similar reinforcing effect is achieved, and the construction cost is reduced. The method has a wide market application prospect in the field of traditional railroad bed foundation treatment.

Description

Technical Field

[0001] This utility model relates to the field of foundation treatment technology in civil engineering, and in particular to a composite foundation structure of beam-type pile-net. Background Technology

[0002] Currently, the main foundation treatment methods in railway subgrade engineering include three major foundation structure forms: pile cap pile network, pile raft, and pile slab. Under the same working conditions, their structural integrity, foundation reinforcement effect (bearing capacity and deformation), and project cost increase sequentially. Existing engineering practices and research show that, from the perspective of settlement control, assuming consistent pile length, pile diameter, and pile spacing, the settlement of a pile raft is approximately 10-20% less than that of a pile cap pile network, and the settlement of a pile slab structure is approximately 20-30% less than that of a pile raft structure.

[0003] The technical specifications state that "in special terrains such as sloping, soft foundations or riverbanks, and in cases of poor foundations or foundations consisting of a single, non-hard-shelled, fluid-plastic silt or silty soil stratum, the overall stability and lateral bearing capacity of the pile network structure must be calculated. For those that do not meet the requirements, measures such as strengthening the lateral connection at the pile top or strengthening the foundation treatment can be taken." The pile cap type pile network structure is the most widely used, but due to the structural characteristics of its discrete piles, it has many shortcomings in applications such as deep soft soil strata, slopes, and high-fill embankments. Furthermore, due to its weak overall integrity, low pile-soil load sharing ratio, and weak soil constraint between piles, there is still room for improvement in its foundation settlement control efficiency.

[0004] In the existing technology, Chinese patents CN102535263A, CN104947560B, and CN109811782A have successively proposed adding tie beams and other integral reinforcing components to improve the lateral stability of soft soil foundations and embankments and reduce the difference in pile-soil settlement on the basis of traditional pile cap type pile network structures. However, there are still redundancies in the structural form and cumbersome construction procedures, which have a certain impact on project investment and construction cycle. Utility Model Content

[0005] To address the problems mentioned in the background art, this utility model proposes a settlement control effect cavity, a simplified structure, and a robust and durable beam-type pile-net composite foundation structure.

[0006] Therefore, the present invention adopts the following technical solution:

[0007] A composite foundation structure consisting of a beam-type pile-net structure includes: a beam, a reinforced cushion layer, and several foundation reinforcement piles, wherein:

[0008] The connecting beam is a one-piece reinforced concrete beam, wherein the reinforced concrete beams are arranged equidistantly in a cross pattern, and square through holes are formed between the reinforced concrete beams.

[0009] Located above the foundation reinforcement pile; the top of the foundation reinforcement pile is embedded in the intersection of the reinforced concrete beam of the connecting beam; the reinforced mattress layer is laid on the connecting beam to form the upper surface of the foundation.

[0010] Preferably, the square through hole has armpit corners at its four corners.

[0011] Preferably, the length of the axle angle is 0.2 to 0.3 m, and the connecting beam is provided with a settlement joint.

[0012] Preferably, the reinforced mattress layer includes a crushed stone mattress layer and geotextile material sandwiched in the crushed stone mattress layer; the square through holes in the connecting beam are also filled with a filling layer.

[0013] Preferably, the thickness of the reinforced mattress layer is 0.5m, wherein the thickness of the crushed stone mattress layer above the geotextile is 0.2m, and the thickness of the crushed stone mattress layer below the geotextile is 0.3m.

[0014] Preferably, the crushed stone cushion layer is made of gravel or crushed stone, and the longitudinal and transverse tensile strength of the geotextile material is ≥100kN / m.

[0015] Preferably, the foundation reinforcement piles are rigid piles with a pile diameter of 0.4 to 0.6 m, a pile spacing of 4 to 6 times the pile diameter, and the distance between the pile tops of the foundation reinforcement piles embedded in the connecting beams is ≥0.05 m.

[0016] Preferably, the cross-sectional width of the reinforced concrete beam of the connecting beam is 0.1 to 0.2 m larger than the pile diameter of the foundation reinforcement pile, and the cross-sectional height of the reinforced concrete beam is 0.5 to 0.8 m.

[0017] Preferably, a plain concrete cushion layer with a thickness of 0.05 to 0.1 m is laid under the connecting beam to serve as the construction working surface for the connecting beam.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention replaces the pile cap structure with a longitudinal and transverse cross beam, which effectively improves the pile-soil stress ratio and enhances the foundation settlement control effect.

[0020] 2. Compared with traditional pile-raft or pile-slab structures, the structure of this utility model can save a lot of engineering investment without changing the reinforcement effect, and has broad market application prospects in the field of traditional railway subgrade foundation treatment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of the foundation treatment for the railway subgrade engineering in the embodiment;

[0022] Figure 2 This is a top view of the connecting beam in an embodiment of this utility model;

[0023] Figure 3 for Figure 1 A magnified schematic diagram of the slope foot structure in the middle circle;

[0024] Figure 4 This is a top view schematic diagram of the connecting beam and plain concrete cushion layer in an embodiment of this utility model;

[0025] In the diagram: 1. Foundation reinforcement pile; 2. Connecting beam; 3. Reinforced mattress layer; 4. Plain concrete cushion layer; 5. Haunch angle; 6. Crushed stone cushion layer; 7. Geotechnical material; 8. Railway subgrade fill material; 9. Filling layer. Detailed Implementation

[0026] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] In one embodiment of this utility model, such as Figure 1 As shown, the lower foundation section is the composite foundation structure of the present invention, which includes several foundation reinforcement piles 1, connecting beams 2 and reinforced mattress layer 3; the foundation section is supported by railway subgrade fill material 8.

[0028] All of the aforementioned foundation reinforcement piles 1 are arranged in a square pattern in the foundation;

[0029] like Figure 2 As shown, the connecting beam 2 is a monolithically formed, equidistantly arranged, intersecting reinforced concrete beam, located above the foundation reinforcement pile 1. A groove is provided at the intersection of the connecting beams 2 on the side facing the foundation reinforcement pile 1, for embedding into the top of the foundation reinforcement pile 1. Square through holes are formed between the reinforced concrete beams, and armholes 5 are provided at the four corners of the square through holes.

[0030] like Figure 3 As shown, the reinforced mattress layer 3 is laid on the top surface of the connecting beam 2, including a crushed stone mattress layer 6 and geotextile material 7 sandwiched therein, and the through holes in the connecting beam 2 are also filled with a filling layer 9.

[0031] like Figure 4 As shown, during construction, a plain concrete pad 4 is first laid in the construction area of ​​the connecting beam, and then it is used as the working surface for the pouring of reinforced concrete for the connecting beam 2.

[0032] In one embodiment of this utility model, the foundation reinforcement pile 1 is a rigid pile, such as a CFG pile, a screw pile, a pipe pile, or a plain concrete pile; the pile diameter is 0.4 to 0.6 m, the pile spacing is 4 to 6 times the pile diameter, and the pile top is embedded in the connecting beam 2 for not less than 0.05 m.

[0033] In one embodiment of this utility model, the cross-sectional width of the connecting beam 2 is 0.1 to 0.2 m larger than the pile diameter of the foundation reinforcement pile, the cross-sectional height is 0.5 to 0.8 m, the length of the haunch angle 5 is 0.2 to 0.3 m, and a settlement joint is provided every 20 to 25 m along the line direction of the connecting beam 2.

[0034] The reinforced mattress layer 3 has a total thickness of 0.5m. Its crushed stone mattress layer 6 and filling layer 9 are made of well-graded gravel or crushed stone that is not easily weathered. The longitudinal and transverse tensile strength of the geotextile material 7 should not be less than 100kN / m.

[0035] The thickness of the plain concrete cushion layer is 0.05 to 0.1 m, and the portion on one side that is wider than the connecting beam is not less than 0.05 m.

[0036] Based on the above technical solution, the beneficial effects achievable by this utility model are: replacing the pile cap structure with longitudinal and transverse intersecting beams effectively improves the pile-soil stress ratio, further enhancing the foundation settlement control effect. Compared with traditional pile-raft or pile-slab structures, the structure of this utility model can save a significant amount of engineering investment while achieving the same or similar reinforcement effect, and has broad market application prospects in the field of traditional railway subgrade foundation treatment.

Claims

1. A composite foundation structure of beam-type pile-net, characterized in that, The utility model relates to a kind of ground reinforcement structure, including: Joint beam (2), reinforced mattress layer (3) and several ground reinforcement piles (1), wherein: The joint beam (2) is integrally formed reinforced concrete beam body, and the beam body is arranged equidistantly in cross direction, and square through hole is formed between the beam body; Above the ground reinforcement pile (1); The top of the ground reinforcement pile (1) is embedded in the intersection of the reinforced concrete beam body of the joint beam (2); The reinforced mattress layer (3) is laid on the joint beam (2), and forms the upper surface of foundation.

2. The structure of the pile-net composite foundation according to claim 1, wherein: The four corners of the square through hole are provided with axillary angle (5).

3. The structure of the pile-net composite foundation according to claim 2, characterized in that: The length of the axillary angle (5) is 0.2-0.3 m, and the joint beam (2) is provided with settlement joint.

4. The structure of the pile-net composite foundation according to claim 2, wherein: The reinforced mattress layer (3) includes gravel cushion (6) and geotechnical material (7) sandwiched in the gravel cushion (6); The square through hole in the joint beam (2) is also filled with filling layer (9).

5. The structure of the pile-net composite foundation according to claim 4, characterized in that: The thickness of the reinforced mattress layer (3) is 0.5 m, wherein the thickness of the gravel cushion (6) above the geotechnical material (7) is 0.2 m, and the thickness of the gravel cushion (6) below the geotechnical material (7) is 0.3 m.

6. The structure of the pile-net composite foundation according to claim 4, wherein: The gravel cushion (6) uses gravel or gravel, and the longitudinal and transverse tensile strength of the geotechnical material (7) is greater than or equal to 100 kN / m.

7. The structure of the pile-net composite foundation according to claim 1, wherein: The ground reinforcement pile (1) is rigid pile, and the pile diameter is 0.4-0.6 m, and the pile spacing is 4-6 times of the pile diameter, and the distance between the top of the ground reinforcement pile (1) and the joint beam (2) is greater than or equal to 0.05 m.

8. The structure of the pile-net composite foundation according to claim 1, wherein: The cross-sectional width of the reinforced concrete beam body of the joint beam (2) is greater than or equal to 0.1-0.2 m than the pile diameter of the ground reinforcement pile (1), and the cross-sectional height of the reinforced concrete beam body is 0.5-0.8 m.

9. The structure of the pile-net composite foundation according to claim 8, characterized in that: Plain concrete cushion (4) is also laid below the joint beam (2), and the thickness of the plain concrete cushion (4) is 0.05-0.1 m, which is used as the construction operation surface of the joint beam (2).

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