Shaft with a special-shaped grille and its method of excavating and sinking a caisson

Abstract

The present invention provides a shaft with a special-shaped grille and a method for excavating and sinking a caisson, which relates to the technical field of shaft excavation. It solves the technical problems existing in the prior art, such as high construction cost, low construction efficiency, and poor operation safety. The shaft with a special-shaped grille includes a shaft wall, a special-shaped grille, a mating surface between the brick formwork of the barrel body and the grille brick formwork, and a steel corner guard installation part. The brick formwork of the barrel body and the grille brick formwork are each made of lime-sand bricks and cement mortar; by chiseling the brick formwork of the barrel body and the grille brick formwork, a cutting edge can be formed at the bottom of the shaft wall and the partition wall. The present invention reduces the construction cost and operation risk, and improves the operation safety and construction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of vertical shaft excavation, and in particular to a vertical shaft with a special-shaped grid and a method for excavating and caissoning the vertical shaft with the special-shaped grid. Background Art

[0002] Vertical shafts with special-shaped grilles are widely used in the field of sewage treatment, but how to scientifically and reasonably design and construct the structure has always been a difficult problem in the engineering field.

[0003] In the prior art, the method for constructing a shaft with a special-shaped grille generally involves first excavating earth at a predetermined construction location to dig a deep pit sufficient to accommodate the shaft with the special-shaped grille. Due to the depth of the deep pit, a large amount of muddy water will seep out of the surrounding soil and flow into the deep pit, especially in low-lying areas or near rivers and lakes. A high-power water pump is required to promptly pump out the muddy water at the bottom of the deep pit. After the muddy water is pumped out, the reinforced concrete can be poured.

[0004] The applicant has found that the prior art has at least the following technical problems:

[0005] The construction method of the shaft with special-shaped grids in the prior art is only suitable for construction in areas with relatively dry soil. When excavating earth near rivers and lakes, a lot of mud and water will seep out of the side walls of the deep pit. The water pumping capacity of the water pump is usually not enough to keep up with the amount of mud and water seeping out. The deep accumulation of mud and water will make it impossible to pour concrete, which seriously delays the construction period. Adding more high-power water pumps is not only time-consuming and labor-intensive, but also reduces construction efficiency and increases construction costs. In addition, the mud and water seeping out during the pumping operation can easily cause the soil around the deep pit to collapse, which in turn causes safety accidents, resulting in poor operation safety. Summary of the invention

[0006] The embodiments of the present invention provide a vertical shaft with a special-shaped grid and a method for digging and caissoning the vertical shaft with the special-shaped grid, which solve the technical problems of high construction cost, low construction efficiency and poor operation safety in the prior art.

[0007] The embodiment of the present invention provides the following technical solutions:

[0008] An embodiment of the present invention provides a vertical shaft with a special-shaped grille, comprising a vertical shaft wall, a special-shaped grille, a matching surface of a barrel brick mold, a matching surface of a grille brick mold, and a steel corner protection installation portion, wherein:

[0009] The shaft walls and special-shaped grilles are all reinforced concrete structures with waterproof properties;

[0010] The special-shaped grille is composed of several partition walls fixedly installed inside the shaft wall;

[0011] The mating surface of the barrel brick formwork is an inclined surface provided on the inner side of the bottom of the shaft wall, and the mating surface of the grid brick formwork is an inclined surface provided at the side edges of both sides of the partition wall; the shaft with the special-shaped grid exists in the above-ground state and the underground state. When the shaft with the special-shaped grid is in the above-ground state, the mating surface of the barrel brick formwork abuts against the barrel brick formwork, and the mating surface of the grid brick formwork abuts against the grid brick formwork;

[0012] The steel corner guard installation part accommodates the steel corner guard that wraps the right-angle corners on the outer side of the shaft wall. The cross-section of the steel corner guard is a steel material in the shape of an "∟". The vertical outer wall of the steel corner guard is flush with the outer side wall of the shaft wall, and the horizontal outer wall of the steel corner guard is flush with the bottom surface of the shaft wall; both the barrel brick formwork and the grid brick formwork are made of lime-sand bricks and cement mortar; by chiseling the barrel brick formwork and the grid brick formwork, a cutting edge can be formed at the bottom of the shaft wall and the partition wall.

[0013] Optionally, the inner walls of the vertical part and the horizontal part of the steel corner guard are welded to the steel bars in the shaft wall through two staggered steel connecting bars.

[0014] Optionally, the vertical surface of the barrel brick formwork is flush with the inner wall of the shaft wall, and the vertical surface of the grid brick formwork is flush with the side wall of the partition wall; in the barrel brick formwork and the grid brick formwork, the cement mortar is between the lime-sand bricks and in the gaps between the lime-sand bricks and the mating surface of the barrel brick formwork or the mating surface of the grid brick formwork.

[0015] Optionally, the mass ratio of cement to sand in the cement mortar is 1 / 5 - 1 / 3, and the mass ratio of water to cement is 0.6 - 0.7.

[0016] Optionally, the lime-sand bricks are stacked in a staggered arrangement in the vertical direction.

[0017] Optionally, the shaft with the special-shaped grid further includes a valve well. The vertical section of the valve well is in a U shape and the well wall of the valve well is integrated with the shaft wall, and the valve well is connected to the bin through a pre-embedded waterproof sleeve;

[0018] A gravel layer is laid below the valve well. When the shaft with the special-shaped grid is in the underground state, the bottom of the valve well abuts against the gravel layer. The vertical cross-sectional shapes of both the gravel layer and the pit accommodating the valve well are in the shape of an inverted right-angled trapezoid, and the space above the gravel layer where the pit accommodating the valve well is located is filled with earthwork.

[0019] Optionally, when the shaft with the special-shaped grid is in the above-ground state, the bottom surfaces of the shaft wall and the partition wall respectively form a cushion pressing surface that presses against the plain concrete cushion on the soil. The plain concrete cushion is made of plain concrete; the plain concrete contains cement, sand, gravel, and water but does not contain steel bars.

[0020] Optionally, the shaft with the special-shaped grille further includes a sealing layer, a drainage and counterweight layer, a plurality of water-blocking bottom plates, and a plurality of cover plates, where:

[0021] The special-shaped grille divides the internal space of the shaft wall into several compartments horizontally, and cover plates are provided on the compartments; different water-blocking bottom plates are respectively arranged in different compartments; the sealing layer is between the water-blocking bottom plate and the soil; the drainage and counterweight layer is located above the water-blocking bottom plate and has a slope; both the shaft wall and the partition wall of the special-shaped grille have construction grooves recessed horizontally inward, and the edges of the water-blocking bottom plates in each compartment are embedded in the construction grooves.

[0022] The method for excavating and sinking the shaft with the special-shaped grille provided by the present invention includes the following steps:

[0023] Step A: Excavate to form a foundation pit, construct a plain concrete cushion layer in the foundation pit, and construct a brick formwork for the cylinder body, a brick formwork for the grille, and place steel corner guards on the plain concrete cushion layer;

[0024] Step B: Construct the lower section of the shaft wall and the lower section of the partition wall on the plain concrete cushion layer, the brick formwork for the cylinder body, the brick formwork for the grille, and the steel corner guards;

[0025] Step C: Chisel off the plain concrete cushion layer, the brick formwork for the cylinder body, and the brick formwork for the grille, so that the cushion pressing surface directly contacts the soil below, and the bottom of the shaft wall and the partition wall forms a cutting edge; carry out excavation work on the soil below the compartment, excavate a pot-bottom-shaped pit on the soil until the lower section of the shaft wall and the lower section of the partition wall sink to the target depth position of the shaft with the special-shaped grille under the action of gravity;

[0026] Step D: Construct the sealing layer and the water-blocking bottom plates in sequence from bottom to top in the compartment, construct the upper section of the shaft wall and the upper section of the partition wall on the lower section of the shaft wall and the lower section of the partition wall, and construct a valve well and a drainage and counterweight layer, and install the cover plate.

[0027] Optionally, the method for excavating and sinking the shaft with the special-shaped grille further includes the following steps:

[0028] Step E: While chiseling off the plain concrete cushion layer, fill the cavity generated after chiseling off the plain concrete cushion layer with sand between the plain concrete cushion layer and the soil below;

[0029] Step F: If the soil at the cutting edge cannot collapse to the central position of the pot-bottom-shaped pit formed by excavation during the excavation process, use a water jet pipe to spray water on the soil at the cutting edge to promote the collapse of the soil to increase the sinking speed;

[0030] Step G: Dig a number of dewatering wells outside the shaft wall. There is a gap between adjacent dewatering wells, and each dewatering well is equipped with a water pump.

[0031] Step H: The water pump continuously sucks water from the dewatering well and discharges the water into a nearby river or lake.

[0032] At least the following technical effects are produced by any of the above technical solutions provided by the embodiments of the present invention:

[0033] The present invention can first build the cylindrical brick formwork, grid brick formwork and the shaft with special-shaped grids on the ground, and then chisel the cylindrical brick formwork and grid brick formwork to form a blade-like cutting edge at the bottom of the shaft wall and the partition wall. At this time, only the earthwork excavation operation needs to be carried out on the soil in the bin to make the shaft with special-shaped grids sink to the ground under its own weight and switch from the ground state to the underground state. The setting of the steel corner protector improves the structural strength and sharpness of the cutting edge, improves the sinking efficiency, and reduces the workload of earthwork excavation. Since both the shaft wall and the special-shaped grids are made of reinforced concrete structures with waterproof performance, a water retaining wall will be formed during the sinking process of the shaft wall, thereby blocking the muddy water on the side wall of the deep pit dug during the earthwork excavation from seeping into the bin and the deep pit, thus avoiding the influence of too much muddy water on the construction progress and construction efficiency, and also saving the cost caused by removing the muddy water. Therefore, the construction cost is lower. Even if some muddy water may gush out from below the deep pit, the amount of muddy water in the deep pit is much less than that in the prior art. At the same time, water is also needed for the construction of the sealing layer itself. Therefore, the muddy water gushing out from the ground not only has a negligible negative impact on the construction, but also saves the step of adding water during the construction of the sealing layer, giving full play to the utility of the on-site muddy water. In addition, the water retaining wall formed during the sinking process of the shaft wall can also prevent the soil around the deep pit from collapsing, thereby avoiding safety accidents caused by the collapse. Therefore, the operation safety is also more ideal, thus solving the technical problems of high construction cost, low construction efficiency and poor operation safety existing in the prior art.

[0034] Since the present invention has good water retaining characteristics, it can not only be applied to occasions with dry soil, but also be suitable for application in occasions with wet soil such as beside rivers or lakes, and the application range is wider. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Through the following drawings, those skilled in the art can better understand the technical effects of the present invention, where:

[0036] Figure 1 is a plan view of the shaft with special-shaped grids provided by the embodiment of the present invention.

[0037] Figure 2 is Figure 1 a cross-sectional view along line A-A.

[0038] Figure 3 is Figure 1 A schematic cross-sectional view along line B-B.

[0039] Figure 4 is Figure 1 A schematic cross-sectional view along line C-C.

[0040] Figure 5 A schematic diagram showing the connection relationship between the middle shaft wall of a shaft with special-shaped gratings and the special-shaped gratings provided in the embodiments of the present invention.

[0041] Figure 6 A schematic diagram showing the connection relationship between the steel bars (thick solid lines represent the steel bar structure) and the concrete (thin solid lines represent the outer contour of the concrete) inside the shaft wall of a shaft with special-shaped gratings provided in the embodiments of the present invention.

[0042] Figure 7 A schematic diagram showing the connection relationship between the steel bars (thick solid lines represent the steel bar structure) and the concrete (thin solid lines represent the outer contour of the concrete) inside one of the partition walls of the special-shaped gratings of a shaft with special-shaped gratings provided in the embodiments of the present invention.

[0043] Figure 8 A schematic diagram showing the connection relationship between the steel bars (thick solid lines represent the steel bar structure) and the concrete (thin solid lines represent the outer contour of the concrete) inside the other partition wall of the special-shaped gratings of a shaft with special-shaped gratings provided in the embodiments of the present invention.

[0044] Figure 9 A schematic diagram showing the positional relationship between a shaft with special-shaped gratings provided in the embodiments of the present invention and a plain concrete cushion when in the above-ground state.

[0045] Figure 10 A schematic diagram showing the connection relationship between the steel corner protection of a shaft with special-shaped gratings provided in the embodiments of the present invention and the steel bars inside the shaft wall.

[0046] Markings in the figure: 1. Shaft wall; 101. Steel bars inside the shaft wall; 2. Special-shaped grating; 3. Cushion pressing surface; 4. Brick tire mold mating surface; 41. Cylinder body brick tire mold mating surface; 42. Grating brick tire mold mating surface; 5. Plain concrete cushion; 6. Steel corner protection; 7. Valve well; 8. Sealing bottom layer; 9. Drainage counterweight layer; 10. Waterproof floor slab; 11. Cover plate; 12. Cylinder body brick tire mold; 13. Vertical convex edge; 14. Horizontal convex edge; 156. Waterproof sleeve; 15. Sleeve body; 16. Limit flange; 17. Construction groove; 18. Gravel layer; 19. Frame column; 20. Steel connecting bars; 21. Sand cushion. Detailed implementation manners

[0047] The following combines the above attachments Figures 1-10More specifically, the preferred embodiments provided by the embodiments of the present invention and many alternative implementation schemes will be described.

[0048] As Figures 1-10 shown, a shaft with a special-shaped grid provided by the present invention includes a shaft wall 1, a special-shaped grid 2, a cushion pressing surface 3, a brick formwork mating surface 4, a steel corner protection installation part, a valve well 7, a sealing layer 8, a drainage counterweight layer 9, a plurality of waterproof bottom plates 10, and a plurality of cover plates 11, wherein:

[0049] Both the shaft wall 1 and the special-shaped grid 2 are reinforced concrete structures with waterproof properties, and both the sealing layer 8 and the drainage counterweight layer 9 are concrete structures with waterproof properties;

[0050] The special-shaped grid 2 is composed of several partition walls fixedly arranged inside the shaft wall 1. The special-shaped grid 2 divides the internal space of the shaft wall 1 into several compartments in the horizontal direction. Each compartment is provided with several openings, and each opening is covered with a cover plate 11. Waterproof sleeves for water passage are embedded in the partition walls, and the waterproof sleeves connect different compartments;

[0051] The cushion pressing surface 3 is arranged at the bottom of the shaft wall 1 and the partition walls, and the cushion pressing surface 3 is parallel to the horizontal plane;

[0052] This shaft with a special-shaped grid has a ground state and an underground state. When this shaft with a special-shaped grid is in the ground state, the cushion pressing surfaces 3 of the shaft wall 1 and the partition walls respectively press against the plain concrete cushion 5 on the soil, and the top surface of the plain concrete cushion 5 is parallel to the horizontal plane; when this shaft with a special-shaped grid is in the underground state, the cushion pressing surfaces 3 of the shaft wall 1 and the partition walls respectively press against the soil;

[0053] The brick formwork mating surface 4 includes a cylinder brick formwork mating surface 41 and a grid brick formwork mating surface 42. The cylinder brick formwork mating surface 41 is an inclined surface arranged on the inner side of the bottom of the shaft wall 1. There is an angle of 50° to 75° between the cylinder brick formwork mating surface 41 and the horizontal plane, and the vertical section of the cylinder brick formwork 12 is a right triangle; when this shaft with a special-shaped grid is in the ground state, the inclined surface of the cylinder brick formwork 12 abuts against the cylinder brick formwork mating surface 41, the horizontal plane of the cylinder brick formwork 12 is flush with the cushion pressing surface 3 and presses against the plain concrete cushion 5, the vertical surface of the cylinder brick formwork 12 is flush with the inner wall of the shaft wall 1, and the width dimension of the plain concrete cushion 5 against which the cushion pressing surface 3 of the shaft wall 1 presses in the horizontal direction is 1.5 - 2.5 times the thickness dimension of the shaft wall 1;

[0054] The mating surface 42 of the grid brick formwork is an inclined surface provided at the side edges on both sides of the partition wall. The vertical section of the grid brick formwork is a right triangle. When the shaft with the special-shaped grid is in the above-ground state, two grid brick formworks are respectively arranged on both sides of the partition wall. The inclined surface of the grid brick formwork abuts against the mating surface 42 of the grid brick formwork. The horizontal plane of the grid brick formwork is flush with the cushion pressing surface 3 and presses against the plain concrete cushion 5. The vertical surface of the grid brick formwork is flush with the side wall of the partition wall. The width dimension of the plain concrete cushion 5 pressed by the cushion pressing surface 3 of the partition wall in the horizontal direction is 1.5 - 2.5 times the thickness dimension of the partition wall.

[0055] The steel corner guard installation part accommodates the steel corner guard 6 that wraps the right-angled corners on the outer side of the shaft wall 1. The cross-section of the steel corner guard 6 is a steel material in the shape of an "L". The vertical outer wall of the steel corner guard 6 is flush with the outer side wall of the shaft wall 1, and the horizontal outer wall of the steel corner guard 6 is flush with the cushion pressing surface 3 of the shaft wall 1.

[0056] When the plain concrete cushion 5, the cylinder brick formwork 12, and the grid brick formwork are chiseled off, a cutting edge can be formed at the bottom of the shaft wall 1 and the partition wall. During the process of excavating the soil inside the shaft wall 1 (in the bin), the shaft with the special-shaped grid can sink to the ground under its own weight and switch from the above-ground state to the underground state.

[0057] The steel corner guard 6 of the present invention can not only protect the right-angled corners on the outer side of the shaft wall 1 and prevent damage to the right-angled corners on the outer side of the shaft wall 1 during the process of chiseling off the plain concrete cushion 5, the cylinder brick formwork 12, and the grid brick formwork, but also increase the sharpness of the cutting edge formed at the bottom of the shaft wall 1 after the plain concrete cushion 5, the cylinder brick formwork 12, and the grid brick formwork are chiseled off, thereby facilitating the improvement of the sinking speed of the shaft with the special-shaped grid and reducing the amount of soil excavation. The cooperation of the structures of the plain concrete cushion 5, the cylinder brick formwork 12, and the grid brick formwork can form a support structure that is firm in the vertical direction but easy to chisel off in the horizontal direction, so that the shaft wall 1 and the partition wall can be made higher in the vertical direction, reducing the frequency of segmented production or even eliminating the need for segmented production when the height of the shaft with the special-shaped grid is low. At the same time, the cutting edge is sharper in the horizontal direction, which is conducive to improving the construction efficiency.

[0058] The vertical section of the valve well 7 is in a U shape and the well wall of the valve well 7 is integrated with the shaft wall 1, and the valve well 7 is connected to the bin through a pre-embedded waterproof sleeve.

[0059] A gravel layer 18 is laid below the valve well 7. When the shaft with the special-shaped grid is in the underground state, the bottom of the valve well 7 abuts against the gravel layer 18.

[0060] The position height of the water-proof bottom plate 10 is higher than the mating surface 4 of the brick formwork. Different water-proof bottom plates 10 are respectively arranged in different bin cells, and the water-proof bottom plates 10 in different bin cells are all at the same height.

[0061] The sealing layer 8 is located between the water-proof bottom plate 10 and the soil, and the thickness dimension of the sealing layer 8 in the vertical direction is not less than the spacing dimension between the cushion pressing surface 3 and the water-proof bottom plate 10.

[0062] The drainage and counterweight layer 9 is made of the same material as the sealing layer 8, and the drainage and counterweight layer 9 is located above the water-proof bottom plate 10 and has a slope. The drainage and counterweight layer 9 can guide the water in some bin cells to the bin cells close to the shaft wall 1 by gravity.

[0063] The openings of the shaft wall 1 and the special-shaped grille 2 have flanges extending in the horizontal direction, and the cover plate 11 is pressed against the flanges and is flush with the top surfaces of the shaft wall 1 and the special-shaped grille 2.

[0064] In the present invention, the plain concrete cushion 5, the cylinder brick formwork 12, the grille brick formwork and the shaft with a special-shaped grille can be first built on the ground, and then the plain concrete cushion 5, the cylinder brick formwork 12 and the grille brick formwork are chiseled away, so that the bottom parts of the shaft wall 1 and the partition wall form a blade-like cutting edge. At this time, only the excavation operation of the soil in the bin cells is needed, and the shaft with the special-shaped grille can sink to the ground under its own weight and switch from the ground state to the underground state. Since both the shaft wall 1 and the special-shaped grille 2 are reinforced concrete structures with waterproof performance, a water retaining wall will be formed during the sinking process of the shaft wall 1, thereby blocking the muddy water on the side wall of the deep pit dug out during the excavation of the soil from seeping into the bin cells and the deep pit, thus avoiding the influence of too much muddy water on the construction progress and construction efficiency, and also saving the cost caused by draining the muddy water. Therefore, the construction cost is lower. Even if some muddy water may gush out from below the deep pit, the amount of muddy water in the deep pit is greatly reduced compared with the prior art. At the same time, water is also needed for the construction of the sealing layer 8 itself. Therefore, the muddy water gushing out from the ground not only has a negligible negative impact on the construction, but also saves the step of adding water during the construction of the sealing layer 8, giving full play to the utility of the on-site muddy water. In addition, the water retaining wall formed during the sinking process of the shaft wall 1 can also prevent the soil around the deep pit from collapsing, thereby avoiding safety accidents caused by the collapse. Therefore, the operation safety is also more ideal.

[0065] Due to the good water retaining characteristics of the present invention, it can not only be applied to the occasions where the soil is dry, but also be suitable for the occasions where the soil is wet, such as beside rivers or lakes, and the application range is wider.

[0066] As an optional embodiment of the present invention, the inner wall of the vertical part and the inner wall of the horizontal part of the steel corner guard 6 in this embodiment are welded to the steel bars 101 in the shaft wall through two staggered steel connecting bars 20. The steel connecting bars 20 increase the connection strength between the steel corner guard 6 and the shaft wall, thereby also increasing the structural strength of the blade foot. The staggered steel connecting bars 20 each have a large angle with the inner wall of the steel corner guard 6, which is conducive to increasing the bending resistance of the steel corner guard 6.

[0067] As an optional embodiment of the present invention, in this embodiment, the vertical surface of the barrel brick mold 12 is flush with the inner wall of the shaft wall, and the vertical surface of the grid brick mold is flush with the side wall of the partition wall; the cement mortar in the barrel brick mold 12 and the grid brick mold is between the lime sand bricks and the gap between the lime sand bricks and the matching surface of the barrel brick mold 12 or the matching surface of the grid brick mold. The above structure occupies little space in the horizontal direction, which can not only reduce the amount of excavation of the foundation pit, but also help save the amount of cement mortar and lime sand bricks.

[0068] As an optional embodiment of the present invention, the mass ratio of cement to sand in the cement mortar in this embodiment is 1 / 5-1 / 3, and the mass ratio of water to cement is 0.6-0.7. The cement mortar obtained by this ratio can not only meet the structural strength requirements of the barrel brick mold 12 and the grid brick mold, but also facilitate chiseling during the subsequent sinking operation.

[0069] As an optional embodiment of the present invention, in this embodiment, the sand-lime bricks are stacked in a staggered arrangement in the vertical direction. The cylindrical brick mold 12 and the sand-lime bricks in the grid brick mold obtained by this structure are evenly stressed at all places, and the overall structure is stable and has strong pressure bearing capacity.

[0070] As an optional embodiment of the present invention, the contour line of the horizontal cross section of the cell in this embodiment is rectangular or right-angled trapezoidal; the section where the flange contacts the cover plate 11 includes a vertical convex edge 13 extending in the vertical direction and a horizontal convex edge 14 extending in the horizontal direction and connected to the vertical convex edge 13 as a whole; the circumferential outer wall of the cover plate 11 abuts against the vertical convex edge 13, and the bottom surface of the edge portion of the cover plate 11 presses against the horizontal convex edge 14;

[0071] The provision of the vertical flange 13 can increase the size of the flange in the vertical direction, thereby improving the flexibility of the arrangement of the horizontal flange 14 in the vertical direction, and can also make the connection area between the horizontal flange 14 and the vertical flange 13 larger, which is beneficial to improving the connection strength of the horizontal flange 14.

[0072] The waterproof sleeve 156 includes a sleeve body 15 with a central axis extending horizontally, and a limiting flange 16 fixedly arranged in the middle of the outer wall of the sleeve body 15 and extending vertically. The limiting flange 16 is embedded in the partition wall of the shaft wall 1 or the special-shaped grid 2, and the port end face of the sleeve body 15 is flush with the vertical surface of the partition wall of the shaft wall 1 or the special-shaped grid 2.

[0073] The waterproof sleeve 156 can serve as a water flow channel between different compartments. Thus, the sedimentation and treatment of sewage can be realized by using different compartments respectively.

[0074] As an alternative embodiment of the present invention, in this embodiment, the plain concrete cushion layer 5 is made of plain concrete; the plain concrete contains cement, sand, gravel and water but does not contain steel bars. The thickness of the plain concrete cushion layer 5 is not less than 150 mm and not more than 250 mm, and the strength grade of the plain concrete is not lower than C20;

[0075] The cylindrical brick formwork 12 and the grid brick formwork are each made of lime-sand bricks and cement mortar, and the lime-sand bricks are stacked in a staggered manner in the vertical direction. The cement mortar is filled in the gaps between the lime-sand bricks. The mass ratio of the lime-sand bricks to the cement mortar is 1 / 3. The brick formwork formed by stacking the lime-sand bricks and the cement mortar in the above manner can not only ensure sufficient strength in the vertical direction to support the shaft wall 1 and the special-shaped grid 2, but also ensure easy chiseling in the horizontal direction.

[0076] The main function of the plain concrete cushion layer 5 is to provide an ideal horizontal support platform. The advantage of using the plain concrete cushion layer 5, lime-sand bricks and cement mortar in combination is that it can not only meet the strength requirements of construction, but also facilitate subsequent chiseling to expose the cutting edge.

[0077] The valve well 7 and the water-proof bottom plate 10 are both made of reinforced concrete, the sealing bottom layer 8 and the drainage counterweight layer 9 are both made of concrete, and the cover plate 11 is made of metal;

[0078] The reinforced concrete material not only has high strength, but also has good waterproof characteristics, and is suitable for application in sewage treatment. The sealing bottom layer 8 can, on the one hand, reduce vibration, and on the other hand, block the influx of groundwater into the compartments.

[0079] The drainage counterweight layer 9 can not only use the gravity of the water flow itself to introduce water into the preset compartments, but also increase the weight of the shaft with the special-shaped grid, thereby improving its stability.

[0080] In the horizontal direction, the width dimension of the gravel layer 18 is larger than the width dimension of the valve well 7. The vertical cross-sectional shapes of both the gravel layer 18 and the pit accommodating the valve well 7 are inverted right-angled trapezoids. The space above the gravel layer 18 where the pit accommodating the valve well 7 is located is filled with earthwork.

[0081] The gravel layer 18 has good vibration damping characteristics. The concave pit with an inverted right trapezoidal vertical cross-sectional shape has a slope for the gravel to fall, facilitating the paving of the gravel. The relatively large top area of the gravel layer 18 with the above structure can ensure that all parts at the bottom of the valve well 7 can be pressed on the gravel layer 18, thus obtaining good vibration damping effects.

[0082] As an alternative embodiment of the present invention, in this embodiment, both the shaft wall 1 and the partition wall of the special-shaped grille 2 have construction grooves 17 that are concave inward in the horizontal direction, and the edges of the water-proof bottom plates 10 in each bin are embedded in the construction grooves 17. The meshing fit between the construction grooves 17 and the water-proof bottom plates 10 can improve the connection reliability and water-proof performance between the two.

[0083] As an alternative embodiment of the present invention, in this embodiment, the shaft wall 1 and the partition wall of the shaft are divided into several sections from bottom to top. The shaft wall 1 and the partition wall of different sections are cast in different time periods, and steel plate water stops for sealing horizontal construction joints are provided between the shaft walls 1 of different sections and between the partition walls of different sections. The wall thickness of the section with the lowest position height in the shaft wall 1 of different sections is the largest, and the wall thickness of the section with the lowest position height in the partition walls of different sections is the largest.

[0084] When the height of the shaft wall 1 is relatively high and it is not convenient to build a scaffolding, a part of the section of the shaft wall 1 can be sunk first and then the remaining sections can be built. At the same time, because the reinforced concrete structure needs to dry and solidify before it can bear a large weight, constructing in time periods and sections can ensure that the structural strength reaches the optimum.

[0085] The steel plate water stop can seal the horizontal construction joints of the shaft wall 1 and the partition wall respectively, thereby improving the water-proof performance of the shaft wall 1 and the partition wall.

[0086] The reason why the wall thickness of the section with the lowest position height is the largest is that the wall body of the section with the lowest position height needs to bear a greater weight. Therefore, setting its wall thickness larger can improve the strength of the foundation and the stability and reliability of the overall structure.

[0087] The cut-and-sink method for a shaft with a special-shaped grille provided by the embodiment of the present invention includes the following steps:

[0088] Step A: Excavate in a predetermined construction area to form a foundation pit, and the depth dimension of the foundation pit is greater than the thickness dimension of the plain concrete cushion 5 of the shaft with a special-shaped grille provided by any technical solution of the embodiment of the present invention;

[0089] Build a plain concrete cushion 5 in the foundation pit, and build a brick formwork 12 for the cylinder body, a brick formwork for the grille and place steel corner guards 6 on the plain concrete cushion 5;

[0090] Step B: Construct the lower section of the shaft wall 1 and the lower section of the partition wall on the plain concrete cushion 5, the brick formwork 12 of the cylinder body, the brick formwork of the grid and the steel corner guard 6.

[0091] Step C: Chisel off the plain concrete cushion 5, the brick formwork 12 of the cylinder body and the brick formwork of the grid, so that the cushion pressing surface 3 directly contacts the soil below, and the bottom of the shaft wall 1 and the partition wall form cutting edges; conduct excavation operations on the soil below the bin, and excavate a pot-shaped pit on the soil until the lower section of the shaft wall 1 and the lower section of the partition wall sink to the target depth position of the shaft with a special-shaped grid under the action of gravity.

[0092] Step D: Construct the sealing layer 8 and the water-proof bottom plate 10 from bottom to top in the bin, construct the upper section of the shaft wall 1 and the upper section of the partition wall on the lower section of the shaft wall 1 and the lower section of the partition wall, and construct the valve well 7; construct the drainage counterweight layer 9 and install the upper cover plate 11.

[0093] In the present invention, the plain concrete cushion 5, the brick formwork 12 of the cylinder body, the brick formwork of the grid are first constructed and the steel corner guard 6 is placed, then the lower section of the shaft wall 1 and the lower section of the partition wall are constructed and then the plain concrete cushion 5, the brick formwork 12 of the cylinder body and the brick formwork of the grid are chiseled off, and then the soil in the bin is excavated, so that the lower section of the shaft wall 1 and the lower section of the partition wall sink to the target depth position under the action of gravity and then the sealing layer 8, the water-proof bottom plate 10, the upper section of the shaft wall 1, the upper section of the partition wall, the valve well 7 and the drainage counterweight layer 9 are constructed, and finally the upper cover plate 11 is installed. This construction method, on the one hand, utilizes the lower section of the shaft wall 1 and the lower section of the partition wall as a water retaining wall, greatly reducing the amount of muddy water seeping into the bin and avoiding the collapse of the surrounding soil, thus improving the construction efficiency and construction safety and reducing the construction cost. On the other hand, during the construction of the shaft wall 1 and the partition wall, the height of the part exceeding the ground is relatively low, which facilitates the erection of the scaffold and reduces the construction difficulty.

[0094] The present invention can also cause the lower section of the shaft wall 1 and the lower section of the partition wall to sink under the action of gravity to a certain height position above the target depth position of the shaft with the special-shaped grid. After constructing the upper section of the shaft wall 1 and the upper section of the partition wall and building the valve well 7, the whole is then sunk to the target depth position of the shaft with the special-shaped grid. Although this method can minimize the seepage of muddy water, on the one hand, it requires arranging two sinking operations, the scaffolding built previously needs to be removed midway, and it is difficult to carry out the excavation operation in different compartments synchronously; on the other hand, the muddy water itself can also be used when constructing the sealing layer 8. When the soil seepage situation is not serious, it is preferably to construct the upper section of the shaft wall 1 and the upper section of the partition wall after the lower section of the shaft wall 1 and the lower section of the partition wall sink to the target depth position of the shaft with the special-shaped grid under the action of gravity.

[0095] As an alternative embodiment of the present invention, before step B in this embodiment, there is also step L: Step L is to detect the bearing capacity of the soil at the bottom of the foundation pit. If the bearing capacity is greater than 130 kPa, a plain concrete cushion 5 is directly constructed on the soil at the bottom of the foundation pit. If the bearing capacity of the soil at the bottom of the foundation pit is less than 130 kPa, a sand cushion 21 with a bearing capacity greater than 130 kPa is first constructed and then a plain concrete cushion 5 is constructed on the sand cushion 21;

[0096] In step C, when the shaft wall 1 and the partition wall sink to a depth of 1 to 3 meters from the target depth position of the shaft with the special-shaped grid, the speed of soil excavation is reduced. After the shaft wall 1 and the partition wall sink to the target depth position of the shaft with the special-shaped grid, continuous observation is carried out for 6 - 10 hours. If it is observed that the settlement amount is less than 10 mm, then step D is implemented;

[0097] The above method can ensure the sinking accuracy of the shaft with the special-shaped grid of the present invention. Once it is found during the sinking process that the settlement amount of some blade feet is relatively large, the excavation speed of the compartments adjacent to the blade feet can be reduced. On the contrary, if it is found that the settlement amount of some blade feet is relatively small, the excavation speed of the compartments adjacent to the blade feet can be increased to correct the deviation.

[0098] The method for excavating and sinking the shaft with the special-shaped grid further includes the following steps:

[0099] Step I: Build a ground building based on the shaft with the special-shaped grid. The ground building includes frame columns 19, horizontal support beams connected between the frame columns 19, and parapets provided on the frame columns 19, ensuring that the vertical projections of the frame columns 19 and the parapets fall on the shaft wall 1.

[0100] The construction method of the above-mentioned above-ground building can ensure that the gravity of the main load-bearing wall in the frame column 19 falls on the part with the greatest structural strength of the shaft structure with special-shaped gratings, thereby improving the structural strength and service life of the entire building. The specific use and structure of the above-ground building can be designed according to needs.

[0101] As an alternative embodiment of the present invention, in the process of excavating a pot-bottom-shaped pit in the soil in step C of this embodiment, it is necessary to synchronously observe the subsidence amount of each inflection point of the shaft wall 1 of the shaft, and correct the position by controlling the excavation speed to ensure that the subsidence amount of each inflection point is consistent.

[0102] This subsidence method can ensure that the structure of the shaft with special-shaped gratings of the present invention will not be damaged due to the lateral pressure of the soil after subsidence.

[0103] As an alternative embodiment of the present invention, the cut-and-sink method of the shaft with special-shaped gratings in this embodiment further includes the following steps: Step E: While chiseling the plain concrete cushion layer, fill the space between the plain concrete cushion layer and the underlying soil with sand to backfill the cavity generated after chiseling the plain concrete cushion layer; this method can ensure that the supporting forces received by each part of the shaft with special-shaped gratings are uniform, which is beneficial to smooth sinking.

[0104] Step F: If the soil at the blade foot cannot collapse towards the central position of the pot-bottom-shaped pit formed by excavation during the excavation process, use a water jet pipe to spray water on the soil at the blade foot to promote the collapse of the soil to increase the sinking speed. The water sprayed on the soil at the blade foot can not only wash away the soil, but also has a lubricating effect on the blade foot. At the same time, the method of spraying water can operate at a long distance and has high construction safety.

[0105] As an alternative embodiment of the present invention, in step C of this embodiment, if the water level in a certain bin is higher than the preset water level, use a water pump to pump away the excess water;

[0106] The cut-and-sink method of the shaft with special-shaped gratings further includes the following steps:

[0107] Step G: Dig a number of dewatering wells at a distance of 2 meters to 5 meters from the outside of the shaft wall of the shaft, with a spacing of 4 meters to 6 meters between adjacent dewatering wells. The diameter of the dewatering wells is 0.3 meters to 0.6 meters, and the depth is 16 meters to 20 meters. Each dewatering well is equipped with a water pump;

[0108] Step H: The water pump continuously sucks water from the dewatering wells and discharges the water into a nearby river or lake.

[0109] The precipitation well can further lower the water level outside the shaft wall, thus requiring a lower power for the water pump. There is no need to equip with an expensive water pump, which is beneficial to cost reduction. At the same time, the precipitation well can minimize the amount of water seeping into the shaft wall. If too much muddy water seeps into the shaft wall, the water pump can be used to pump out the excess water to ensure the smooth progress of the project. Even if it is impossible to completely avoid too much muddy water seepage in some special occasions, compared with the prior art, the amount of muddy water that needs to be pumped out in the present invention has been greatly reduced. The present invention reduces the negative impact of muddy water on the project progress to the lowest possible level.

[0110] The above technical solutions are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. A shaft with a special-shaped grille, characterized in that: It includes a shaft wall, a special-shaped grille, the mating surface of the brick formwork for the cylinder body, the mating surface of the brick formwork for the grille, and the steel angle protection installation part, where: Both the shaft wall and the special-shaped grille are reinforced concrete structures with waterproof performance; The special-shaped grille is composed of several partition walls fixedly arranged inside the shaft wall; The mating surface of the brick formwork for the cylinder body is an inclined surface arranged on the inner side of the bottom of the shaft wall, and the mating surface of the brick formwork for the grille is an inclined surface arranged at the side edges of both sides of the partition wall; when the shaft with the special-shaped grille is in the above-ground state, the mating surface of the brick formwork for the cylinder body abuts against the brick formwork for the cylinder body, and the mating surface of the brick formwork for the grille abuts against the brick formwork for the grille; The steel angle protection installation part accommodates and wraps the steel angle protection at the right-angle corners on the outer side of the shaft wall. The cross-section of the steel angle protection is a steel material in the shape of "∟". The vertical outer wall of the steel angle protection is flush with the outer side wall of the shaft wall, and the horizontal outer wall of the steel angle protection is flush with the bottom surface of the shaft wall; the brick formwork for the cylinder body and the brick formwork for the grille are each made of lime-sand bricks and cement mortar; by chiseling the brick formwork for the cylinder body and the brick formwork for the grille, the bottom of the shaft wall and the partition wall can form a cutting edge.

2. The shaft with a special-shaped grille according to claim 1, characterized in that: The inner walls of the vertical part and the horizontal part of the steel angle protection are welded to the steel bars in the shaft wall through two cross-arranged steel connecting bars.

3. The shaft with a special-shaped grille according to claim 1, characterized in that: The vertical surface of the brick formwork for the cylinder body is flush with the inner wall of the shaft wall, and the vertical surface of the brick formwork for the grille is flush with the side wall of the partition wall; in the brick formwork for the cylinder body and the brick formwork for the grille, the cement mortar is between the lime-sand bricks and in the gaps between the lime-sand bricks and the mating surface of the brick formwork for the cylinder body or the mating surface of the brick formwork for the grille.

4. The shaft with a special-shaped grille according to claim 3, characterized in that: In the cement mortar, the mass ratio of cement to sand is 1 / 5 - 1 / 3, and the mass ratio of water to cement is 0.6 - 0.

7.

5. The shaft with a special-shaped grille according to claim 1, characterized in that: The lime-sand bricks are stacked in a staggered manner in the vertical direction.

6. The shaft with a special-shaped grille according to claim 1, characterized in that: The shaft with the special-shaped grille also includes a valve well. The vertical cross-section of the valve well is in a U shape, and the well wall of the valve well is integrated with the shaft wall, and the valve well is connected to the bin through a pre-buried waterproof casing; There is a gravel layer laid below the valve well. When the shaft with the special-shaped grille is in the underground state, the bottom of the valve well abuts against the gravel layer. The vertical cross-section shapes of both the gravel layer and the pit accommodating the valve well are inverted right-angled trapezoids, and the space above the gravel layer where the pit accommodating the valve well is located is filled with earthwork.

7. The shaft with a special-shaped grille according to claim 6, characterized in that: When the shaft with the special-shaped grille is in the above-ground state, the bottom surfaces of the shaft wall and the partition wall respectively form a cushion pressing surface that presses against the plain concrete cushion on the soil. The plain concrete cushion is made of plain concrete; the plain concrete contains cement, sand, stones, and water but does not contain steel bars.

8. The shaft with a special-shaped grille according to claim 7, characterized in that: The shaft with the special-shaped grille also includes a sealing layer, a drainage and counterweight layer, several waterproof bottom plates, and several covers, where: The special-shaped grid divides the internal space of the shaft wall into several compartments horizontally, and cover plates are provided on the compartments; different water-proof bottom plates are respectively arranged in different compartments; the sealing layer is located between the water-proof bottom plate and the soil; the drainage and counterweight layer is located above the water-proof bottom plate and has a slope; both the shaft wall and the partition wall of the special-shaped grid have construction grooves recessed horizontally, and the edges of the water-proof bottom plates in each compartment are embedded in the construction grooves.

9. The method for excavating and sinking a caisson of a shaft with a special-shaped grille according to claim 8, characterized in that: It includes the following steps: Step A: Excavate to form a foundation pit, construct a plain concrete cushion in the foundation pit, and construct a cylinder brick formwork, a grid brick formwork and place steel corner guards on the plain concrete cushion. Step B: Construct the lower section of the shaft wall and the lower section of the partition wall on the plain concrete cushion, the cylinder brick formwork, the grid brick formwork and the steel corner guards. Step C: Chisel off the plain concrete cushion, the cylinder brick formwork and the grid brick formwork, so that the cushion pressing surface directly contacts the underlying soil, and the bottom of the shaft wall and the partition wall form cutting edges; carry out excavation work on the soil below the compartment, and excavate a pot-shaped concave pit on the soil until the lower section of the shaft wall and the lower section of the partition wall sink to the target depth position of the shaft with a special-shaped grid under the action of gravity. Step D: Construct the sealing layer and the water-proof bottom plate in sequence from bottom to top in the compartment, construct the upper section of the shaft wall and the upper section of the partition wall on the lower section of the shaft wall and the lower section of the partition wall, and construct a valve well and a drainage and counterweight layer, and install the cover plate.

10. The excavation and sinking method of the shaft with a special-shaped grid according to claim 9, characterized in that: The excavation and sinking method of the shaft with a special-shaped grid further includes the following steps: Step E: While chiseling off the plain concrete cushion, fill the cavity generated after chiseling off the plain concrete cushion with sand between the plain concrete cushion and the underlying soil. Step F: If the soil at the cutting edge cannot collapse to the central position of the pot-shaped concave pit formed by excavation during the excavation process, use a water jet pipe to spray water on the soil at the cutting edge to promote the collapse of the soil to increase the sinking speed. Step G: Dig several dewatering wells outside the shaft wall, with intervals between adjacent dewatering wells, and a water pump is equipped in each dewatering well. Step H: The water pump continuously sucks water from the dewatering well and discharges the water into the nearby river or lake.

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