一种用于地铁建设的悬臂式预应力管桩基坑支挡结构

Abstract

本实用新型公开了一种用于地铁建设的悬臂式预应力管桩基坑支挡结构，包括至少两排预应力管桩、挡土面板和现浇钢筋混凝土冠梁。预应力管桩靠近地质层设置，挡土面板位于管桩外侧。设置第一、第二、第三注浆加固区，形成整体土体注浆加固区。基坑底部设置定位孔，用于安装管桩。定位孔竖向设置，管桩插入后，孔壁与管桩间存在间隙层，内设填充体。该结构通过预应力管桩、挡土面板和现浇钢筋混凝土冠梁组合，形成稳固的基坑支护体系，有效抵抗土压力和水压力，确保基坑开挖安全稳定。注浆加固提高土体强度，定位孔便于管桩安装，间隙层填充增强整体稳定性。管桩采用高强度预应力预制管桩，提高支档结构可靠性和稳定性。

Claims

1. A cantilevered prestressed pipe pile foundation pit support structure for subway construction, characterized in that: It includes at least two rows of prestressed pipe piles, retaining panels, and cast-in-place reinforced concrete capping beams. The prestressed pipe piles are set close to the geological layer, the retaining panels are set outside the prestressed pipe piles, and the cast-in-place reinforced concrete capping beams are set on top of the prestressed pipe piles and retaining panels. A first grouting reinforcement zone is set between the geological layer and the prestressed pipe piles, a second grouting reinforcement zone is set between adjacent prestressed pipe piles, and a third grouting reinforcement zone is set between the retaining panel and the adjacent prestressed pipe piles; the first grouting reinforcement zone, the second grouting reinforcement zone, and the third grouting reinforcement zone form an integral soil grouting reinforcement zone. Positioning holes are set at the bottom of the foundation pit near the geological layer. The diameter of the positioning holes is larger than that of the prestressed pipe piles. The positioning holes are used to install the prestressed pipe piles. The positioning holes are set vertically. After the prestressed pipe piles are inserted into the positioning holes, there is a gap layer between the positioning hole wall and the prestressed pipe piles. Filler is set in the gap layer.

2. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 1, characterized in that: The prestressed pipe piles are arranged in three rows, with at least 6 prestressed pipe piles in each row, and the spacing between adjacent prestressed pipe piles in each row is consistent.

3. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 2, characterized in that: The three rows of prestressed pipe piles have the same structure, and the ends of the three rows of prestressed pipe piles are aligned.

4. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 1, characterized in that: The thickness of the retaining panel is 100mm-200mm.

5. The cantilever prestressed pipe pile retaining structure for subway construction according to any one of claims 1-4, characterized in that: A drainage pipe is installed on the retaining panel, and the drainage pipe is installed at an angle; the drainage pipe is inserted obliquely into the soil grouting reinforcement area.

6. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 1, characterized in that: The filler is fine aggregate concrete.

7. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 1, characterized in that: The prestressed pipe pile is equipped with reinforcing bars, the top of which is a top longitudinal bar that extends into the cast-in-place reinforced concrete capping beam. The cast-in-place reinforced concrete capping beam is also equipped with reinforcing anchor bars, the bottom of which is connected to the reinforcing bars. The top of the reinforcing anchor bars is a bent section.

8. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 7, characterized in that: The lower section of the top longitudinal reinforcement is the pile top welded reinforcement, which is part of the reinforcing reinforcement; the pile top welded reinforcement is welded to the prestressed pipe pile. A first baffle and a reinforcing bar are installed at the welded bar at the top of the pile. The first baffle is fixed inside the prestressed pipe pile, and the reinforcing bar is placed on the first baffle. The two ends of the reinforcing bar are fixed to two reinforcing bars respectively. The prestressed pipe pile section above the first baffle is filled with concrete.

9. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 8, characterized in that: A reinforcing section structure is provided on the prestressed pipe pile, which includes a limiting rod and a second baffle. The limiting rod passes through the prestressed pipe pile from the outside and into the prestressed pipe pile, and the second baffle is set on the limiting rod. A section of reinforcing concrete is set on the second baffle.

10. The cantilever prestressed pipe pile retaining structure for subway construction according to claim 1 or 9, characterized in that: An anchoring structure is provided between one prestressed pipe pile and another prestressed pipe pile. The anchoring structure includes a base plate, anchor rods, connecting plates, adjusting rods, and clamps. An anchor rods are provided on the back of the base plate, and the connecting plates are provided on the front of the base plate. The adjusting rods are connected to the connecting plates, and adjusting rods are provided on both the left and right sides of the connecting plates. Clamps are provided at the ends of the adjusting rods. The clamps are used to connect the prestressed pipe piles.

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