Permeable pipe pile supporting structure

Abstract

The utility model relates to the technical field of foundation pit supporting, and provides a pervious pipe pile supporting structure which comprises a plurality of pervious pipe piles and a plurality of high-pressure jet grouting piles which are alternately arranged along the edge of a foundation pit. The permeable pipe pile comprises a pile body, filler and a filter material. A plurality of water permeable holes are formed in the soil facing side of the pile body, water drainage holes are formed in the soil backing side of the pile body, a cavity for communicating the water permeable holes with the water drainage holes is formed in the pile body, and the cavity is filled with filler and filter materials; the arrangement height of the drainage holes is larger than the pit bottom elevation of the foundation pit. While foundation pit supporting is conducted through the permeable pipe piles, the underground water level of an active area is lowered through cooperation of the permeable holes, the filter materials and the drainage holes; a supporting structure and a dewatering structure are organically combined, on the premise that the soil body supporting and retaining function is achieved, secondary construction of a dewatering well outside a pit is avoided, resources are saved, the underground water level of an active area is reduced, the soil body shear strength of the active area is improved, and foundation pit stability is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of foundation pit support, and particularly relates to a permeable pipe pile support structure. Background Technique

[0002] In foundation pit engineering, in addition to considering the support of soil mass, attention also needs to be paid to the control of groundwater. Usually, for foundation pits with good soil quality, row pile support is adopted. To avoid the collapse of the soil between piles, wire mesh shotcrete is used, and drainage holes are arranged between the piles to enable the groundwater in the active area to drain, reducing the water pressure brought by groundwater. For strata containing silt soil and flowing plastic soil, when row pile support is adopted, to avoid flowing soil between piles, a water stop curtain is usually set behind the piles or high-pressure jet grouting piles are set between the piles. However, the groundwater in the active area cannot drain, and the water pressure accumulates, which is not conducive to the safety of the foundation pit support structure. Adopting dewatering measures can reduce the moisture in the soil, improve the soil strength, reduce the lateral displacement of the foundation pit soil mass, stabilize the foundation pit, and eliminate quicksand.

[0003] Usually, the support structure and groundwater control belong to two different systems. Among them, setting dewatering wells is one of the main ways of groundwater control. However, setting dewatering wells outside the pit requires separate drilling and well completion, and water pumping with a water pump is adopted, which not only occupies the construction space outside the pit but also is not conducive to shortening the construction period. Content of the Utility Model

[0004] In view of the above problems in the prior art, the present application proposes a permeable pipe pile support structure, which not only has the function of retaining soil for the foundation pit but also can reduce the groundwater level in the active area.

[0005] The utility model proposes a permeable pipe pile support structure, which includes a plurality of permeable pipe piles and a plurality of high-pressure jet grouting piles arranged alternately along the edge of the foundation pit; the permeable pipe pile includes a pile body, filler, and filter material; a plurality of water permeable holes are arranged on the soil-facing side of the pile body, a drainage hole is arranged on the soil-back side of the pile body, a cavity communicating the water permeable holes and the drainage hole is arranged inside the pile body, and the filler and the filter material are filled in the cavity; the setting height of the drainage hole is higher than the bottom elevation of the foundation pit.

[0006] Further, the filler is backfilled in the cavity of the pile body below the bottom elevation of the foundation pit, and the filter material is backfilled above the bottom elevation of the foundation pit; the filler is an impermeable material, and the filter material is a water permeable material.

[0007] Further, a drainage pipe is arranged in the drainage hole, one end of the drainage pipe extends into the filter material, and the other end extends out into the foundation pit.

[0008] Further, the part of the drainage pipe extending into the filter material is provided with water filtering holes, and the water filtering holes are wrapped with permeable geotextile.

[0009] Furthermore, there are multiple water-permeable holes, which are arranged at intervals along the vertical direction of the pile body.

[0010] Furthermore, there are multiple water-drainage holes, which are arranged at intervals along the vertical direction of the pile body.

[0011] Furthermore, a drainage ditch is arranged along the edge of the foundation pit below the water-drainage holes; the drainage ditch is communicated with a sump well.

[0012] Furthermore, a conical pile tip is arranged at the bottom of the pile body.

[0013] Furthermore, the pile body is of a cylindrical reinforced concrete structure, steel bars are arranged inside the pile body, and the distances between the water-permeable holes and the water-drainage holes and the steel bars are greater than the minimum cover thickness of the steel bars.

[0014] Furthermore, the height of the water-permeable holes is higher than that of the water-drainage holes.

[0015] The beneficial effects of the present utility model include: while carrying out foundation pit support through the permeable pipe pile, the cooperation of the water-permeable holes, the filter material and the water-drainage holes is utilized to lower the groundwater level in the active area; the support structure and the dewatering structure are organically combined. On the premise of meeting the function of retaining the soil body, it not only avoids the secondary construction of the dewatering wells outside the pit, saves resources, but also lowers the groundwater level in the active area, improves the shear strength of the soil body in the active area, and is beneficial to the stability of the foundation pit. The structure is simple, the existing drainage system of the foundation pit is fully utilized, no additional equipment investment is required, and the dewatering power consumption is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic cross-sectional structure view of the permeable pipe pile support structure of the present utility model.

[0017] Figure 2 is Figure 1 an enlarged schematic view at the water-drainage hole in

[0018] Figure 3 is a schematic cross-sectional view of the pile body of the present utility model.

[0019] Figure 4 is a schematic plan layout view of the permeable pipe pile support structure of the present utility model.

[0020] In the figure: 1 - water-permeable hole; 2 - water-drainage hole; 2-1 - water-filtering hole; 2-2 - permeable geotextile; 2-3 - drainage pipe; 3 - pile body; 3-1 - main reinforcement; 3-2 - stirrup; 3-3 - reinforcement hoop; 4 - pile tip; 5 - filler; 6 - filter material; 7 - drainage ditch; 8 - high-pressure jet grouting pile; 9 - permeable pipe pile. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present utility model will be further described in detail below with reference to the drawings and specific embodiments.

[0022] As shown Figures 1 - 4 in the figure, the permeable pipe pile support structure of the present utility model, as Figure 4 shown in the figure, includes a plurality of permeable pipe piles 9 and a plurality of high-pressure jet grouting piles 8 arranged alternately along the foundation pit edge; as Figures 1 - 3 shown in the figure, the permeable pipe pile includes a permeable hole 1, a water discharge hole 2, a pile body 3, a pile tip 4, a filler 5, and a filter material 6.

[0023] The pile body 3 is a cylindrical reinforced concrete structure with a certain wall thickness and cavity. A conical pile tip 4 is provided at the bottom of the pile to facilitate pile sinking.

[0024] A plurality of permeable holes 1 are uniformly arranged on the soil-facing side of the pile body 3 above the bottom of the pit. The cavity of the pile body 3 is filled with a filler 5 and a filter material 6. A water discharge hole 2 is provided at a certain height above the bottom of the pit on the soil-back side of the pile body. A drainage ditch 7 is arranged along the foundation pit edge below the water discharge hole 2.

[0025] The filler 5 backfilled in the cavity of the pile body 3 below the bottom elevation of the foundation pit is an impermeable material, and the filter material 6 filled above the bottom elevation of the pit is a permeable material.

[0026] The groundwater in the active area (outside the foundation pit) of the foundation pit flows into the cavity through the permeable holes 1, is filtered by the filter material 6, and is discharged into the bottom drainage ditch 7 through the water discharge holes 2, and is collected in the sump and then pumped into the drainage pipe network.

[0027] The water discharge holes 2 can be arranged in multiple numbers at different vertical positions of the pile body 3 according to the layered excavation depth of the foundation pit.

[0028] The water discharge hole 2 is a circular opening on the soil-back side of the pile body 3, and a drainage pipe 2-3 is inserted into the hole. One end of the pipe body of the drainage pipe 2-3 is provided with a filter hole 2-1 and is wrapped with a permeable geotextile 2-2. This area of the drainage pipe extends into the filter material 6. The opening diameter of the water discharge hole 2 of the pile body 3 is slightly larger than the outer diameter of the drainage pipe 2-3.

[0029] The permeable holes 1 and water discharge holes 2 on the pile body 3 should be arranged between the main reinforcement 3-1, stirrups 3-2, and reinforcement hoops 3-3 of the pile body 3 to ensure the minimum concrete cover thickness of the reinforcement and avoid corrosion of the reinforcement.

[0030] According to the geological conditions, high-pressure jet grouting piles 8 are set between the support piles when necessary to prevent groundwater from seeping into the foundation pit between the piles. According to the groundwater situation, the permeable support pipe piles 9 can be arranged at intervals with ordinary support piles.

[0031] According to the actual dewatering situation outside the pit, when it is necessary to reduce the amount of dewatering or stop dewatering, reverse grouting can be carried out through the water discharge holes 2 for plugging.

[0032] During specific use, first hoist the prefabricated permeable pipe pile 9 to the pile position. Before pile driving, adjust the orientation of the pile body 3, place the side with the permeable holes 1 on the outside of the foundation pit, and the side with the drain holes 2 on the inside of the foundation pit, and then pile driving construction can be carried out. During the pile driving process, it is necessary to adjust the orientation of the pile body 3 according to the actual situation until the design elevation is reached. According to the geological conditions, high-pressure jet grouting piles 8 are arranged between the permeable pipe piles 9 to prevent water leakage and soil loss between the permeable pipe piles 9; according to the abundance of groundwater, the permeable support pipe piles 9 and ordinary support piles can be arranged at intervals.

[0033] After the construction of the retaining structure is completed, backfill the cavity of the permeable pipe pile 9, densely backfill the impermeable filler 5 into the cavity, and the backfill height is near the bottom elevation of the pit, and then backfill the filter material 6. Preferably, the filler 5 can use the existing impermeable soil in the site, and the filter material 6 can use gravel.

[0034] After the soil is excavated to expose the drain holes 2, first dredge the possible soil in the drain holes 2, then insert a drainage pipe 2-3 with a filter hole 2-1 at one end and wrapped with a permeable geotextile 2-2, and complete the drainage ditch 7 in the pit. Then, the groundwater is collected by the in-pit drainage system and pumped out of the pit to complete the active zone dewatering.

[0035] In summary, a permeable pipe pile support structure provided by the present utility model, while meeting the function of retaining the soil body, not only avoids the secondary construction of the external dewatering wells of the foundation pit, saves resources, but also reduces the groundwater level in the active zone and improves the shear strength of the soil in the active zone, which is beneficial to the stability of the foundation pit. The structure is simple, makes full use of the existing drainage system of the foundation pit, does not require additional equipment investment, and saves electricity for dewatering.

[0036] The above is only the preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above embodiments. All technical solutions falling within the idea of the present utility model belong to the protection scope of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the principle of the present utility model should also be regarded as the protection scope of the present utility model.

Claims

1. A permeable pipe pile support structure, characterized in that: It comprises a plurality of permeable pipe piles and a plurality of high-pressure rotary jet piles alternately arranged along the edge of a foundation pit; the permeable pipe piles comprise a pile body, fillers and filter materials; a plurality of permeable holes are arranged on the soil-facing side of the pile body, a drainage hole is arranged on the soil-receiving side of the pile body, a cavity connecting the permeable holes and the drainage holes is arranged inside the pile body, and the cavity is filled with the fillers and the filter materials; the drainage holes are arranged at a height higher than the pit bottom elevation of the foundation pit.

2. A permeable pipe pile support structure according to claim 1, characterized in that: The cavity of the pile body is backfilled with the filler below the pit bottom elevation, and is backfilled with the filter material above the pit bottom elevation; the filler is a water-impermeable material, and the filter material is a water-permeable material.

3. A permeable pipe pile support structure according to claim 2, characterized in that: A drainage pipe is arranged in the drainage hole, one end of the drainage pipe extends into the filter material, and the other end extends into the foundation pit.

4. A permeable pipe pile support structure according to claim 3, characterized in that: The portion of the drainage pipe extending into the filter material is provided with a water filtering hole, and the water filtering hole is wrapped with a permeable geotextile.

5. A permeable pipe pile support structure according to claim 1, characterized in that: There are a plurality of water-permeable holes, which are arranged at intervals along the vertical direction of the pile body.

6. A permeable pipe pile support structure according to claim 1, characterized in that: There are a plurality of drainage holes, which are arranged at intervals along the vertical direction of the pile body.

7. A permeable pipe pile support structure according to claim 1, characterized in that: A drainage ditch is arranged below the drainage hole along the edge of the foundation pit; the drainage ditch is connected to a water collection well.

8. The permeable pipe pile support structure according to claim 1, characterized in that: A conical pile tip is arranged at the bottom of the pile body.

9. A permeable pipe pile support structure according to claim 1, characterized in that: The pile body is a cylindrical reinforced concrete structure, and steel bars are built into the pile body. The distance between the water-permeable holes and the drainage holes and the steel bars is greater than the minimum protective layer thickness of the steel bars.

10. A permeable pipe pile support structure according to claim 1, characterized in that: The height of the water-permeable hole is higher than the height of the water-draining hole.

Images