A long casing bottom flange water stop device for high water level pile foundation construction

Abstract

The utility model discloses a long casing bottom flange water stop device for high water level pile foundation construction relates to building engineering pile foundation construction technical field, and this device includes long casing, flange plate, sealing pad layer and cement mortar plugging layer, and the flange plate is in long casing installation in position after, and the field splicing fixed outside its bottom, sealing pad layer is located between flange plate and basement floor, and forms first mechanical pressure tight seal, cement mortar plugging layer is located between flange plate inner surface and long casing outer wall, and the annular region in the ring that flange plate lower surface and basement floor enclose forms second rigid seal. The utility model discloses through "field installable flange plate + double -deck composite sealing", has solved traditional casing bottom plugging not dense, the problem of easy leakage, especially applicable to complex working conditions such as pressure water stratum and existing building bottom plate opening, has the advantages such as water stop reliable, construction flexible, quality controllable.

Description

Technical Field

[0001] This utility model relates to the field of building pile foundation construction technology, specifically to a long casing bottom flange water-stopping device for high water level pile foundation construction. Background Technology

[0002] In urban construction, deep foundation pit projects are becoming increasingly common, and bored piles are widely used. When constructing in areas with high confined water head and complex hydrogeological conditions, it is necessary to use ultra-long steel casings to penetrate the existing basement floor slab in order to control the water head pressure and prevent the pile hole from collapsing and the sudden surge of confined water.

[0003] Traditional construction methods typically involve sealing the gap between the casing and the bottom slab by filling it with ordinary cement mortar. This method has significant drawbacks: firstly, the mortar is easily eroded by water before it hardens, resulting in insufficient density; secondly, mortar shrinkage can easily create gaps; and thirdly, it relies on a single material for sealing, leading to poor reliability. If the sealing fails, high-pressure groundwater will seep into the foundation pit along the outer wall of the casing, affecting not only construction safety and pile quality but also potentially causing serious accidents such as flooding of the foundation pit and settlement of surrounding strata.

[0004] Therefore, there is a need for a long casing bottom water-stopping device that has more reliable sealing performance, is easy to construct, and can effectively resist high water pressure. Utility Model Content

[0005] The technical problem to be solved by this utility model is to address the issues of insufficient sealing, easy leakage, and inadequate water pressure resistance of traditional mortar at the bottom of long casings in the prior art. This utility model provides a simple, reliable sealing device for the bottom flange of long casings that can effectively prevent the sudden surge of pressurized water at high water levels.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: A bottom flange water-stopping device for long casing for high water level pile foundation construction, comprising a long casing, a flange, a sealing gasket layer and a cement mortar sealing layer; the flange is spliced ​​and fixed on the outside of the bottom of the long casing after the long casing is installed in place; the sealing gasket layer is placed between the flange and the basement floor slab to form a first mechanical compression seal; the cement mortar sealing layer is placed between the inner surface of the flange and the outer wall of the long casing, and in the annular area enclosed by the lower surface of the flange and the basement floor slab to form a second rigid seal.

[0007] Furthermore, the flange is a split flange, which is composed of two semi-circular steel plates spliced ​​together. Its inner diameter is consistent with the outer diameter of the long protective sleeve, and it is fixed to the long protective sleeve by bolt connection.

[0008] Furthermore, the flange has a width of 100mm to 200mm and a thickness of not less than 16mm.

[0009] Furthermore, the sealing gasket is a water-swellable waterproof strip. Of course, other sealing materials can also be used.

[0010] Furthermore, the flange is provided with grouting holes evenly distributed throughout its circumference.

[0011] Furthermore, the number of grouting holes is 4 to 8.

[0012] Furthermore, each grouting hole is equipped with a grouting pipe.

[0013] Compared with the prior art, the present invention has the following beneficial effects: Double sealing ensures reliable performance: The first layer forms an initial seal by pressing the sealing gasket layer with the flange; the second layer forms a dense cement mortar sealing layer by applying a dense layer and injecting pressure grout. This double protection greatly improves the reliability of water stopping.

[0014] Strong water pressure resistance: The flange expands the water-stopping cross-section, and the grout is fully filled, which can effectively resist the pressure of high-pressure water head.

[0015] Convenient construction and controllable quality: All components can be prefabricated in the factory, and the on-site installation process is clear. The grouting process is visible and controllable, which facilitates ensuring construction quality.

[0016] High applicability: It can be widely used in various high-water-level pile foundation projects that need to penetrate the bottom slab, and is especially suitable for sensitive environments with extremely high requirements for water stoppage.

[0017] Significant economic benefits: Low initial investment cost, but can effectively avoid engineering risks and economic losses caused by leakage, resulting in high overall benefits.

[0018] In summary, this utility model solves the problem of poor sealing and easy leakage at the bottom of traditional casings through the structure of "on-site installable flange + double composite seal". It is especially suitable for complex working conditions such as pressurized water strata and openings in the foundation slab of existing buildings. It has the advantages of reliable water sealing, flexible construction and controllable quality. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional view of the structure of a bottom flange water-stopping device for a long casing used in high-water-level pile foundation construction, according to an embodiment of the present invention.

[0021] Figure 2 for Figure 1Top view of the embodiment shown.

[0022] Explanation of the reference numerals in the figure: 1-Long casing, 2-Flange, 3-Sealing gasket, 4-Grouting hole, 5-Grouting pipe, 6-Basement floor slab, 7-Cement mortar sealing layer. Detailed Implementation

[0023] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] Reference Figure 1 and Figure 2 This embodiment provides a bottom flange water-stopping device for long casing for high-water-level pile foundation construction, including a long casing 1, a flange 2, a sealing gasket 3, and a cement mortar sealing layer 7; after the long casing 1 is installed in place, the flange 2 is spliced ​​and fixed on the outside of the bottom of the long casing 1 on site; the sealing gasket 3 is placed between the flange 2 and the basement floor slab 6 to form a first mechanical compression seal; the cement mortar sealing layer 7 is placed between the inner surface of the flange 2 and the outer wall of the long casing 1, and in the annular area enclosed by the lower surface of the flange 2 and the basement floor slab 6 to form a second rigid seal.

[0025] In this embodiment, the flange 2 is a split flange, which is composed of two semi-circular steel plates (including a horizontal part and a vertical part, the horizontal part is attached to the basement floor slab 6, and the vertical part is attached to the long protective sleeve 1) spliced ​​together. Its inner diameter is consistent with the outer diameter of the long protective sleeve 1, and it is fixed to the long protective sleeve 1 by bolt connection; the width is 100mm to 200mm, and the thickness is not less than 16mm.

[0026] In this embodiment, the sealing gasket 3 is a water-swellable sealing strip. Of course, other sealing materials can also be used.

[0027] In this embodiment, the flange 2 has four grouting holes 4 evenly distributed around its circumference, and each grouting hole 4 is equipped with a grouting pipe 5. Of course, the number of grouting holes 4 and grouting pipes 5 can also be set to 5 to 8.

[0028] In this embodiment, the cement mortar sealing layer 7 uses cement mortar with a mass ratio of 1:1. The cement mortar contains water glass additives accounting for 4% of the cement mass.

[0029] Specific implementation process: During construction, holes are first precisely drilled in the existing or newly built basement floor slab 6 according to the design. Then, a lifting device is used to vertically lower the long casing 1 (usually a steel casing with a wall thickness of 16mm) so that it passes through the holes in the floor slab and is adjusted to the design elevation and verticality.

[0030] Key Step 1: On-site Installation of the Flange. After the long casing 1 is securely in place, the flange 2 is assembled. The flange 2 is preferably composed of two semi-circular steel plates, with an inner diameter matching the outer diameter of the long casing 1, a width of 150mm, and a thickness of 16mm. The two flange halves are placed over the bottom outer side of the long casing 1 at the predetermined elevation, aligned, and then circumferentially fastened with high-strength bolts to form a solid integral unit with the outer wall of the long casing. This design avoids the problem of the integral flange needing to be hoisted and passed through holes along with the long casing.

[0031] Key Step Two: Formation of the First Seal. A continuous ring of water-swellable rubber sealing strip is pre-attached or subsequently applied to the lower surface of flange 2 as a sealing gasket 3. By further tightening flange 2 or fine-tuning the long protective sleeve 1, the sealing gasket 3 is fully compressed between flange 2 and the bottom surface of basement floor 6, utilizing its own elasticity and water-swellable properties to form the first effective flexible waterproof barrier.

[0032] Key Step Three: Construction of the Second Seal. Within the annular area enclosed by the outer wall of the long casing 1, the inner surface of the flange 2, and the lower surface of the flange 2 and the basement floor slab 6, a polymer-modified cement waterproof mortar mixed with 4% water glass by weight of cement is applied densely to form a cement mortar sealing layer 7. This layer, after curing, exhibits high strength, good impermeability, and excellent adhesion to both metal and concrete, forming a robust second rigid waterproof barrier. The auxiliary grouting holes 4 pre-drilled on the flange 2 can be used for supplementary grouting in special circumstances, but are not the primary sealing method.

[0033] The installation of this water-stopping device is completed by following the above three steps. Through its innovative split installation method and double-seal principle, this device provides a reliable and practical solution for waterproofing the bottom of the casing in high-water-level pile foundation construction.

[0034] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these are within the scope of protection of the present invention.

Claims

1. A bottom flange water-stopping device for long casings used in high-water-level pile foundation construction, characterized in that: It includes a long casing, a flange, a sealing gasket, and a cement mortar sealing layer; the flange is spliced ​​and fixed on the outside of the bottom of the long casing after it is installed in place; the sealing gasket is placed between the flange and the basement floor slab to form the first mechanical compression seal; the cement mortar sealing layer is placed between the inner surface of the flange and the outer wall of the long casing, and in the annular area enclosed by the lower surface of the flange and the basement floor slab to form the second rigid seal.

2. The water-stopping device for the bottom flange of a long casing used in high-water-level pile foundation construction according to claim 1, characterized in that: The flange is a split flange, which is composed of two semi-circular steel plates spliced ​​together. Its inner diameter is the same as the outer diameter of the long protective sleeve, and it is fixed to the long protective sleeve by bolt connection.

3. The water-stopping device for the bottom flange of a long casing used in high-water-level pile foundation construction according to claim 2, characterized in that: The flange has a width of 100mm to 200mm and a thickness of not less than 16mm.

4. A bottom flange water-stopping device for long casing used in high-water-level pile foundation construction according to claim 1, 2, or 3, characterized in that: The sealing gasket is a water-swellable waterproof strip.

5. A bottom flange water-stopping device for long casing used in high-water-level pile foundation construction according to claim 1, 2, or 3, characterized in that: The flange has grouting holes evenly distributed around its circumference.

6. A bottom flange water-stopping device for long casing used in high-water-level pile foundation construction according to claim 5, characterized in that: The number of grouting holes is 4 to 8.

7. A bottom flange water-stopping device for long casing used in high-water-level pile foundation construction according to claim 6, characterized in that: Each grouting hole is equipped with a grouting pipe.

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