LU502171B1 - Method for pouring artesian energy-dissipating concrete to deep foundation pit and concrete automatic-flow energy-dissipating structure - Google Patents

Abstract

Wherein deep foundation pit concrete pouring is performed by a concrete artesian energy- dissipating structure; arrangements, geometric dimensions, thicknesses and materials of energy- dissipating boxes and drainage guide pipes are determined before construction; a plurality of stages of energy-dissipating boxes with holes formed in upper and bottom end are sequentially arranged in the depth direction of the deep foundation pit at intervals from top to bottom, kept consistent in the vertical direction and connected with a lining wall of the foundation pit by fixing structures; the energy-dissipating boxes are communicated with the drainage guide pipes; and after concrete is introduced into the drainage guide pipe at the top, then the concrete with high dynamic energy flows through the plurality of stages of energy-dissipating boxes and drainage guide pipes in sequence for stage-by-stage energy-dissipating buffering, and finally pours to a discharging pipe at the lowest end.

Description

DESCRIPTION METHOD FOR POURING ARTESIAN ENERGY-DISSIPATING CONCRETE TO DEEP FOUNDATION PIT AND CONCRETE AUTOMATIC-FLOW ENERGY- DISSIPATING STRUCTURE

TECHNICAL FIELD The present invention relates to a foundation pit construction method, in particular to a method for pouring artesian energy-dissipating concrete to a deep foundation pit.

BACKGROUND ART With the continuous acceleration of China’s urbanization, the urban size and population size are also rapidly increased correspondingly, and urban land is also increasingly under shortage. Buildings gradually develop in the air and under the ground in order to relieve the problems of urban overground resource shortage, traffic jams, etc. Various buildings and structures such as high-rise and even super-high-rise buildings, underground parking lots, underground malls and underground stations are developed rapidly. In order to meet construction requirements, it is necessary to increase the excavation depth of a foundation pit and expand the excavation scale of the foundation pit usually, resulting in continuous emergence of corresponding construction problems. In ordinary foundation pit construction, concrete can be directly transported to the bottom of the foundation pit from the surface by pipelines, and then normal pouring work can be performed. However, when the foundation pit has deep depth, if the concrete is conveyed by a conventional method, it may generate large dynamic energy due to gravity acting in the conveying process, that is, the flow velocity is too high. Impact force of the high-flow-velocity concrete will affect normal pouring work of the concrete. In addition, concrete characters may change due to excessively high flow velocity, then construction quality is affected, even construction accidents may be caused seriously, and normal use of structures is affected. In order to solve the problem of excessively high flow velocity caused by the deep foundation pit and guarantee the concrete characters during deep foundation pit pouring, it is urgently necessary to invent a simple and reliable pouring method for weakening artesian dynamic energy of concrete in a deep foundation pit based on a novel structure, thereby reducing the construction risk and improving the construction quality.

BRIEF SUMMARY OF THE INVENTION The present invention provides a method for pouring artesian energy-dissipating concrete to a deep foundation pit as for the above prior art, which mainly aims at solving the problem that the concrete artesian velocity is too high during deep foundation pit concrete transportation, reducing pouring impact force and guaranteeing concrete characters based on a concrete artesian energy-dissipating structure and concrete drainage guide pipes. In order to solve the above technical problems, the present invention provides a method for pouring artesian energy-dissipating concrete to a deep foundation pit, deep foundation pit concrete pouring is performed by a concrete artesian energy-dissipating structure, and the method comprises the following steps:

Step 1, preparing concrete, by constructors, according to construction requirements before construction, and determining the maximum flow velocity of the concrete placement and required concrete characters; Step 2, determining arrangement densities, geometric dimensions, thicknesses and materials of energy-dissipating boxes according to the depth of the foundation pit and concrete characters, and determining pipe diameters, pipe wall thicknesses and materials of drainage guide pipes according to the arrangement densities, concrete characters and physical properties of the energy-dissipating boxes; Step 3, arranging a plurality of stages of energy-dissipating boxes sequentially in the depth direction of the deep foundation pit at intervals from top to bottom according to the arrangement densities of the energy-dissipating boxes, wherein upper and bottom ends of the energy- dissipating boxes are provided with holes; the upper end of the energy-dissipating box located at the top is provided with a drainage guide pipe communicating with the energy-dissipating box, and every two vertically-adjacent energy-dissipating boxes are communicated with a drainage guide pipe; and the plurality of stages of energy-dissipating boxes are kept consistent in the vertical direction; Step 4, all the energy-dissipating boxes being connected with a lining wall of the foundation pit by fixing structures; and a discharging pipe led to an underground deep layer is arranged at the bottom of the energy-dissipating box located at the lowest end; Step 5, implementing concrete pouring, introducing the concrete into an inlet of the drainage guide pipe at upper end of the energy-dissipating box located at the top and above the surface, then the concrete with high dynamic energy flowing through the plurality of stages of energy- dissipating boxes and drainage guide pipes in sequence for stage-by-stage energy-dissipating buffering, and finally pouring to a bottom plate of the underground deep layer by the discharging pipe at the lowest end.

Meanwhile, the present invention provides the concrete artesian energy-dissipating structure achieving the above method for pouring the artesian energy-dissipating concrete to the deep foundation pit, comprising energy-dissipating boxes sequentially arranged in the depth direction of the deep foundation pit at intervals from top to bottom, wherein upper and bottom ends of the energy-dissipating boxes are provided with holes; the upper end of the energy-dissipating box located at the top is provided with a drainage guide pipe communicating with the energy- dissipating box, and every two vertically-adjacent energy-dissipating boxes are communicated with a drainage guide pipe; all the energy-dissipating boxes are connected with a lining wall of the foundation pit by fixing structures; and a discharging pipe led to an underground deep layer is arranged at the bottom of the energy-dissipating box at the lowest end.

Further, the method for pouring the artesian energy-dissipating concrete to the deep foundation pit in the present invention, wherein: a drainage funnel is arranged at the inlet of the drainage guide pipe at upper end of the energy- dissipating box located at the top and above the surface, so as to guarantee that the concrete evenly flows into the drainage guide pipes, and the size, thickness and material of the drainage funnel are determined according to the artesian velocity (the artesian velocity is lower than the maximum concrete pouring flow velocity) of the concrete.

The energy-dissipating boxes are made of metal, and steel preferably.

The axial direction of the drainage guide pipes is the vertical direction; optionally, the axial direction of the drainage guide pipes and the depth direction of the deep foundation pit have an included angle of 25-35°, and all the drainage guide pipes have same inclination directions. The fixing structures between the energy-dissipating boxes and the lining wall are triangular supports, so as to avoid position change of the energy-dissipating boxes during concrete impact, and the fixing structures are fixedly connected with the lining wall of the foundation pit by anchoring structures. Compared with the prior art, the present invention has the following beneficial effects: By reducing the concrete artesian velocity, the problem of large impact force due to excessively high artesian velocity during deep foundation pit concrete conveying is effectively solved, the concrete characters are guaranteed, construction is facilitated, and the construction quality is guaranteed. The method for pouring the artesian energy-dissipating concrete to the deep foundation pit is simple in construction process and structure, and the speed reduction effect meets requirements.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of an energy-dissipating structure and drainage guide pipes installed between an underground diaphragm wall and a stratum; FIG. 2 is a side view of arrangement of the energy-dissipating structure and the drainage guide pipes shown in FIG. 1. FIG. 3 is a front view of an energy-dissipating structure used in the present invention. FIG. 4 is a schematic diagram of concrete flow based on an energy-dissipating structure and drainage guide pipes in the present invention. In the drawings: 1: drainage funnel 2: drainage guide pipe 3: energy-dissipating box 4: fixing structure 5: stratum 6: lining wall 7: bottom plate 8: anchoring structure

DETAILED DESCRIPTION OF THE PRESENT INVENTION The design concept of a method for pouring artesian energy-dissipating concrete to a deep foundation pit is as follows: deep foundation pit concrete pouring is performed by a concrete artesian energy-dissipating structure, the dynamic energy of the concrete with high dynamic energy flowing in from drainage guide pipes on upper portions is reduced through the buffering effect of a plurality of stages of energy-dissipating boxes, and the concrete is conveyed to lower portions by drainage guide pipes located at bottom of the energy-dissipating boxes for stage-by- stage energy dissipating. The energy-dissipating boxes are connected with a lining wall by triangular fixing structures, so as to guarantee that the energy-dissipating boxes still can be fixed when bearing large impact force. A drainage funnel is arranged at an inlet of the drainage guide pipe on the surface, so that the concrete conveniently flows into the drainage guide pipes and is transported to an underground deep layer. The concrete can be stably transported from the surface to the deep foundation pit through the buffering effect of the energy-dissipating boxes and transportation of the drainage guide pipes, the concrete is kept in good character and controlled at low flow velocity, so as to reduce its impact to bottom pouring of the deep foundation pit, its characters are guaranteed, and construction requirements are met.

The concrete artesian energy-dissipating structure adopted in the present invention is simple, convenient to construct and capable of meeting deep foundation pit concrete pouring requirements.

The present invention is further illustrated with reference to accompanying drawings and specific embodiments below, but the embodiments below do not limit the present invention at all.

The concrete artesian energy-dissipating structure achieving the method for pouring the artesian energy-dissipating concrete to the deep foundation pit provided in the present invention, as shown in FIG. 1 and FIG. 4, comprises energy-dissipating boxes 3 sequentially arranged in the depth direction of the deep foundation pit at intervals from top to bottom, wherein upper and bottom ends of the energy-dissipating boxes 3 are provided with holes; the upper end of the energy-dissipating box 3 located at the top is provided with a drainage guide pipe 2 communicating with the energy-dissipating box 3, and every two vertically-adjacent energy- dissipating boxes 3 are communicated with a drainage guide pipe 2; all the energy-dissipating boxes 3 are connected with a lining wall 6 of a supporting stratum 5 by fixing structures 4, the fixing structures 4 are triangular supports and fixedly connected with the lining wall 6 by anchoring structures 8, as shown in FIG. 3 and FIG. 4, so as to avoid position change of the energy-dissipating boxes 3 during concrete impact, and a discharging pipe for pouring of a bottom plate 7 of an underground deep layer is arranged at the bottom of the energy-dissipating box 3 at the lowest end.

The arrangement densities (intervals), geometric dimensions, thicknesses and materials of the energy-dissipating boxes 3 can be reasonably set according to construction conditions such as concrete pouring requirements, concrete characters and the depth of the foundation pit, and the wall thicknesses of the energy-dissipating boxes 3 can be properly increased so as to reduce deformation caused by concrete impact.

As shown in FIG. 3, the drainage guide pipes 2 provide channels for concrete flow, and the axial direction of the drainage guide pipes is the vertical direction; optionally, the axial direction of the drainage guide pipes 2 and the depth direction of the deep foundation pit have an included angle of 25-35°, and all the drainage guide pipes 2 have same inclination directions so that it is guaranteed that the energy-dissipating structure is kept consistent in the vertical direction.

The drainage guide pipes 2 can be made of metal, and the pipe diameters and pipe wall thicknesses of the drainage guide pipes 2 can be reasonably set according to the construction conditions such as the concrete pouring requirements, concrete characters and the depth of the foundation pit.

As shown in FIG. 1 and FIG. 2, a drainage funnel 1 is arranged at the inlet of the drainage guide pipe at upper end of the energy-dissipating box located at the top and above the surface, so as to guarantee that the concrete evenly flows into the drainage guide pipes, and the size, thickness and material of the drainage funnel 1 are determined according to the artesian velocity of the concrete.

The method for pouring the artesian energy-dissipating concrete to the deep foundation pit by the concrete artesian energy-dissipating structure provided in the present invention comprises the following steps: Constructors prepare concrete according to construction requirements before construction, and the maximum pouring flow velocity of the concrete and required concrete characters are determined.

Arrangement densities, geometric dimensions, thicknesses and materials of energy- dissipating boxes 3 are determined according to the depth of the foundation pit and the concrete characters.

Pipe diameters, pipe wall thicknesses and materials of drainage guide pipes 2 are determined according to the arrangement densities, concrete characters and physical properties of the energy-dissipating boxes 3; and the size, thickness and material of the drainage funnel 1 are determined according to the artesian velocity of the concrete.

In the embodiment, the maximum flow velocity Vmax of the concrete is equal to 10 m/s.

Gravitational potential energy is converted into concrete flow dynamic energy according to an energy conversion formula. mgh = 5 pre” The allowable maximum flow velocity Vmax = 10 m/s of the concrete is substituted so that the length h of the drainage guide pipes 2 can be obtained. pe 1608 - da 2x10 0 The length h of the drainage guide pipes 2 obtained is maximum length, the arrangement densities (intervals) of the energy-dissipating boxes 3 are 5 m/piece, and if the depth H of the foundation pit is 60 m, the arrangement number # of the energy-dissipating boxes 3 is: HA 60 42 3 SE mn IS es OX j yr i 5 It is assumed that the internal diameter D of the drainage guide pipes 2 is 0.1 m, the pipe wall thickness 7 is 0.005 m, and the drainage guide pipes are made of stainless steel.

The volume V of each drainage guide pipe 2 can be calculated to: y HD wx 01° 5 — 004m ON 000000000007 FF SNS 200000000000000000000000 THE 4 X i.

EFI 4 4 ; The size of the energy-dissipating boxes 3 can be designed according to the above calculations.

It is assumed that length (L) * width (B) of the energy-dissipating boxes 3 is equal to 0.3 m * 0.3 m, and the thickness is 0.01 m.

The minimum height hy min of the energy-dissipating boxes 3 can be calculated according to the volume V of each drainage guide pipe 2 as: ; V 04 0.45 Slo puy PTT BR pees = LAS RER L6 63x03 Meanwhile, a safety coefficient f can be additionally set to increase the design height hy of the energy-dissipating boxes 3: hx = fhx min = 1.2 *0.45=054m At this moment, the heights of the drainage guide pipes 2 and the energy-dissipating boxes 3 are larger than the depth H of the foundation pit, and then the drainage guide pipes 2 can be inclined, as shown in FIG. 3 and FIG. 5.

The maximum size of the drainage funnel 1 can be calculated according to the depth H of the foundation pit and the internal diameter D of the drainage guide pipes 2. It is assumed that length (Ly) * width (By) of the drainage funnel 1 is equal to 1 m * 1 m, and then the height of the drainage funnel is: wi gow EX 0.1° x 60 = 047m

YELLE TAIN It is assumed that the thickness of the drainage funnel 1 is 0.01 m, and it is made of stainless steel. In the embodiment, 12 energy-dissipating boxes, 13 drainage guide pipes (including a discharging pipe) and 1 drainage funnel which are all made of stainless steel are manufactured according to the above design. Wherein, the size of the energy-dissipating boxes is as follows: length * width * height = 0.3 m * 0.3 m *0.54 m, and the thickness is 0.01 m; and the size of the drainage guide pipes is as follows: length is 5 m, pipe diameter is 0.1 m, and pipe wall thickness is 0.005 m. The size of the drainage funnel is: length * width * height=1m * 1 m * 0.47 m, and the thickness is 0.01 m. One energy-dissipating box is arranged every 5 m in the depth (e.g. 60 m) direction of the deep foundation pit from top to bottom in sequence according to the arrangement densities of the energy-dissipating boxes 3, there are 12 energy-dissipating boxes 3, wherein upper and bottom ends of the energy-dissipating boxes are provided with holes; a fixing structure 4 is installed on the lower portion of each energy-dissipating box according to the normal pouring requirements of the foundation pit, as shown in FIG. 3, the fixing structures 4 are triangular supports and connected with the lining wall 6 by anchoring structures 8, then the energy-dissipating boxes 3 are fixed to the anchoring structures 8. In the embodiment, the anchoring structures 8 are made of iron, and the length may be 0.3 m or above. The upper and bottom ends of the energy- dissipating boxes 3 are inserted into the drainage guide pipes 2 and sequentially connected from top to bottom. In the embodiment, the axial direction of the drainage guide pipes 2 and the depth direction of the deep foundation pit have an included angle of 30°, and all the drainage guide pipes have same inclination directions, and therefore the plurality of stages of energy-dissipating boxes 3 are kept consistent in the vertical direction. The drainage funnel 1 is installed at the top of the drainage guide pipe 2 at the uppermost end, and the discharging pipe for pouring of the bottom plate 7 of the underground deep layer is arranged at the bottom of the energy-dissipating box 3 at the lowest end. Concrete pouring is implemented. The pre-prepared concrete is poured into the drainage funnel 1 according to requirements, the concrete introduced into an inlet of the drainage guide pipe at upper end of the energy-dissipating box 3 located at the top and above the surface, the concrete reduced flow velocity in the energy-dissipating boxes 3, and then the concrete passed through the drainage guide pipe 2 located at the bottom end of the energy-dissipating box 3 and flowed toward the deep position of the foundation pit, so as to reach the following energy-dissipating boxes 3 on lower portions (e.g. next stages) with the flow velocity reduced. The concrete flowed downwards stage3-by-stage in a similar way, and the concrete with high dynamic energy flowing from the drainage guide pipe 2 at the uppermost end sequentially flowed through the plurality of stages of energy-dissipating boxes 3 and drainage guide pipes 2 in sequence for stage-by-stage energy-dissipating buffering, and finally flowed to the energy-dissipating boxes 3 at the lowest end and poured to a pouring position by the discharging pipe arranged at the bottom of the energy-dissipating box 3 located at the lowest end.

The method for pouring the artesian energy-dissipating concrete to the deep foundation pit is adopted for construction, thereby relieving the problem of high dynamic energy during deep foundation pit concrete transportation, reducing impact force of the concrete, keeping the concrete characters, meeting the pouring requirements and guaranteeing the construction quality.

Although the present invention is described with reference to accompanying drawings above, it is not limited to the above specific implementations, the above specific implementations are only schematic instead of limitative, those ordinarily skilled in the art can make many transformations without departing from the objective of the present invention under inspiration of the present invention, and these transformations all belong to protection of the present invention.

Claims (10)

1. A method for pouring artesian energy-dissipating concrete to a deep foundation pit, characterized in that deep foundation pit concrete pouring is performed by a concrete artesian energy-dissipating structure, and it comprises the following steps: Step 1, preparing concrete, by constructors, according to construction requirements before construction, and determining the maximum flow velocity of the concrete placement and required concrete characters; Step 2, determining arrangement densities, geometric dimensions, thicknesses and materials of energy-dissipating boxes (3) according to the depth of the foundation pit and concrete characters, and determining pipe diameters, pipe wall thicknesses and materials of drainage guide pipes (2) according to the arrangement densities, concrete characters and physical properties of the energy-dissipating boxes (3); Step 3, arranging a plurality of stages of energy-dissipating boxes (3) sequentially in the depth direction of the deep foundation pit at intervals from top to bottom according to the arrangement densities of the energy-dissipating boxes (3), wherein upper and bottom ends of the energy-dissipating boxes (3) are provided with holes; the upper end of the energy-dissipating box (3) located at the top is provided with a drainage guide pipe (2) communicating with the energy- dissipating box (3), and every two vertically-adjacent energy-dissipating boxes (3) are communicated with a drainage guide pipe (2); and the plurality of stages of energy-dissipating boxes (3) are kept consistent in the vertical direction; Step 4, all the energy-dissipating boxes (3) being connected with a lining wall (6) of the foundation pit by fixing structures (4); and a discharging pipe led to an underground deep layer is arranged at the bottom of the energy-dissipating box (3) located at the lowest end, Step 5, implementing concrete pouring, introducing the concrete into an inlet of the drainage guide pipe (2) at upper end of the energy-dissipating box (3) located at the top and above the surface, then the concrete with high dynamic energy flowing through the plurality of stages of energy-dissipating boxes (3) and drainage guide pipes (2) in sequence for stage-by- stage energy-dissipating buffering, and finally pouring to a bottom plate of the underground deep layer by the discharging pipe at the lowest end.

2. The method for pouring the artesian energy-dissipating concrete to the deep foundation pit according to claim 1, characterized in that a drainage funnel (1) is arranged at the inlet of the drainage guide pipe (2) at upper end of the energy-dissipating box located at the top and above the surface, and the size, thickness and material of the drainage funnel (1) are determined according to the artesian velocity of the concrete.

3. The method for pouring the artesian energy-dissipating concrete to the deep foundation pit according to claim 1, characterized in that the energy-dissipating boxes (3) are made of metal.

4. The method for pouring the artesian energy-dissipating concrete to the deep foundation pit according to claim 2, characterized in that the energy-dissipating boxes (3) are made of steel.

5. The method for pouring the artesian energy-dissipating concrete to the deep foundation pit according to claim 1, characterized in that the axial direction of the drainage guide pipes (2) is the vertical direction; optionally, the axial direction of the drainage guide pipes (2) and the depth direction of the deep foundation pit have an included angle of 25-35°, and all the drainage guide pipes (2) have same inclination directions.

6. The method for pouring the artesian energy-dissipating concrete to the deep foundation pit according to claim 1, characterized in that the fixing structures (4) are triangular supports, and the fixing structures (4) are fixedly connected with the lining wall (6) by anchoring structures (8).

7. À concrete artesian energy-dissipating structure achieving the method for pouring the artesian energy-dissipating concrete to the deep foundation pit according to any one of claims 1- 6, characterized in that the energy-dissipating structure comprises energy-dissipating boxes (3) sequentially arranged in the depth direction of the deep foundation pit at intervals from top to bottom, wherein upper and bottom ends of the energy-dissipating boxes (3) are provided with holes; the upper end of the energy-dissipating box (3) located at the top is provided with a drainage guide pipe communicating with the energy-dissipating box (3), and every two vertically-adjacent energy-dissipating boxes (3) are communicated with a drainage guide pipe (2); all the energy-dissipating boxes (3) are connected with a lining wall (6) by fixing structures (4); and a discharging pipe led to an underground deep layer 1s arranged at the bottom of the energy- dissipating box (3) at the lowest end.

8. The concrete artesian energy-dissipating structure according to claim 7, characterized in that the axial direction of the drainage guide pipes (2) is the vertical direction; optionally, the axial direction of the drainage guide pipes (2) and the depth direction of the deep foundation pit have an included angle of 25-35°, and all the drainage guide pipes (2) have same inclination directions.

9. The concrete artesian energy-dissipating structure according to claim 7, characterized in that a drainage funnel (1) 1s arranged at the inlet of the drainage guide pipe (2) at upper end of the energy-dissipating box located at the top and above the surface, and the size, thickness and material of the drainage funnel (1) are determined according to the artesian velocity of the concrete.

10. The concrete artesian energy-dissipating structure according to claim 7, characterized in that arrangement densities, geometric dimensions, thicknesses and materials of energy- dissipating boxes (3) are determined according to the depth of the foundation pit and concrete characters, and pipe diameters, pipe wall thicknesses and materials of drainage guide pipes (2) are determined according to the arrangement densities, concrete characters and physical properties of the energy-dissipating boxes (3).